URL
https://opencores.org/ocsvn/open8_urisc/open8_urisc/trunk
Subversion Repositories open8_urisc
[/] [open8_urisc/] [trunk/] [gnu/] [binutils/] [bfd/] [elf32-xtensa.c] - Rev 88
Go to most recent revision | Compare with Previous | Blame | View Log
/* Xtensa-specific support for 32-bit ELF. Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. This file is part of BFD, the Binary File Descriptor library. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ #include "sysdep.h" #include "bfd.h" #include <stdarg.h> #include <strings.h> #include "bfdlink.h" #include "libbfd.h" #include "elf-bfd.h" #include "elf/xtensa.h" #include "xtensa-isa.h" #include "xtensa-config.h" #define XTENSA_NO_NOP_REMOVAL 0 /* Local helper functions. */ static bfd_boolean add_extra_plt_sections (struct bfd_link_info *, int); static char *vsprint_msg (const char *, const char *, int, ...) ATTRIBUTE_PRINTF(2,4); static bfd_reloc_status_type bfd_elf_xtensa_reloc (bfd *, arelent *, asymbol *, void *, asection *, bfd *, char **); static bfd_boolean do_fix_for_relocatable_link (Elf_Internal_Rela *, bfd *, asection *, bfd_byte *); static void do_fix_for_final_link (Elf_Internal_Rela *, bfd *, asection *, bfd_byte *, bfd_vma *); /* Local functions to handle Xtensa configurability. */ static bfd_boolean is_indirect_call_opcode (xtensa_opcode); static bfd_boolean is_direct_call_opcode (xtensa_opcode); static bfd_boolean is_windowed_call_opcode (xtensa_opcode); static xtensa_opcode get_const16_opcode (void); static xtensa_opcode get_l32r_opcode (void); static bfd_vma l32r_offset (bfd_vma, bfd_vma); static int get_relocation_opnd (xtensa_opcode, int); static int get_relocation_slot (int); static xtensa_opcode get_relocation_opcode (bfd *, asection *, bfd_byte *, Elf_Internal_Rela *); static bfd_boolean is_l32r_relocation (bfd *, asection *, bfd_byte *, Elf_Internal_Rela *); static bfd_boolean is_alt_relocation (int); static bfd_boolean is_operand_relocation (int); static bfd_size_type insn_decode_len (bfd_byte *, bfd_size_type, bfd_size_type); static xtensa_opcode insn_decode_opcode (bfd_byte *, bfd_size_type, bfd_size_type, int); static bfd_boolean check_branch_target_aligned (bfd_byte *, bfd_size_type, bfd_vma, bfd_vma); static bfd_boolean check_loop_aligned (bfd_byte *, bfd_size_type, bfd_vma, bfd_vma); static bfd_boolean check_branch_target_aligned_address (bfd_vma, int); static bfd_size_type get_asm_simplify_size (bfd_byte *, bfd_size_type, bfd_size_type); /* Functions for link-time code simplifications. */ static bfd_reloc_status_type elf_xtensa_do_asm_simplify (bfd_byte *, bfd_vma, bfd_vma, char **); static bfd_reloc_status_type contract_asm_expansion (bfd_byte *, bfd_vma, Elf_Internal_Rela *, char **); static xtensa_opcode swap_callx_for_call_opcode (xtensa_opcode); static xtensa_opcode get_expanded_call_opcode (bfd_byte *, int, bfd_boolean *); /* Access to internal relocations, section contents and symbols. */ static Elf_Internal_Rela *retrieve_internal_relocs (bfd *, asection *, bfd_boolean); static void pin_internal_relocs (asection *, Elf_Internal_Rela *); static void release_internal_relocs (asection *, Elf_Internal_Rela *); static bfd_byte *retrieve_contents (bfd *, asection *, bfd_boolean); static void pin_contents (asection *, bfd_byte *); static void release_contents (asection *, bfd_byte *); static Elf_Internal_Sym *retrieve_local_syms (bfd *); /* Miscellaneous utility functions. */ static asection *elf_xtensa_get_plt_section (struct bfd_link_info *, int); static asection *elf_xtensa_get_gotplt_section (struct bfd_link_info *, int); static asection *get_elf_r_symndx_section (bfd *, unsigned long); static struct elf_link_hash_entry *get_elf_r_symndx_hash_entry (bfd *, unsigned long); static bfd_vma get_elf_r_symndx_offset (bfd *, unsigned long); static bfd_boolean is_reloc_sym_weak (bfd *, Elf_Internal_Rela *); static bfd_boolean pcrel_reloc_fits (xtensa_opcode, int, bfd_vma, bfd_vma); static bfd_boolean xtensa_is_property_section (asection *); static bfd_boolean xtensa_is_insntable_section (asection *); static bfd_boolean xtensa_is_littable_section (asection *); static bfd_boolean xtensa_is_proptable_section (asection *); static int internal_reloc_compare (const void *, const void *); static int internal_reloc_matches (const void *, const void *); static asection *xtensa_get_property_section (asection *, const char *); extern asection *xtensa_make_property_section (asection *, const char *); static flagword xtensa_get_property_predef_flags (asection *); /* Other functions called directly by the linker. */ typedef void (*deps_callback_t) (asection *, bfd_vma, asection *, bfd_vma, void *); extern bfd_boolean xtensa_callback_required_dependence (bfd *, asection *, struct bfd_link_info *, deps_callback_t, void *); /* Globally visible flag for choosing size optimization of NOP removal instead of branch-target-aware minimization for NOP removal. When nonzero, narrow all instructions and remove all NOPs possible around longcall expansions. */ int elf32xtensa_size_opt; /* The "new_section_hook" is used to set up a per-section "xtensa_relax_info" data structure with additional information used during relaxation. */ typedef struct xtensa_relax_info_struct xtensa_relax_info; /* The GNU tools do not easily allow extending interfaces to pass around the pointer to the Xtensa ISA information, so instead we add a global variable here (in BFD) that can be used by any of the tools that need this information. */ xtensa_isa xtensa_default_isa; /* When this is true, relocations may have been modified to refer to symbols from other input files. The per-section list of "fix" records needs to be checked when resolving relocations. */ static bfd_boolean relaxing_section = FALSE; /* When this is true, during final links, literals that cannot be coalesced and their relocations may be moved to other sections. */ int elf32xtensa_no_literal_movement = 1; /* Rename one of the generic section flags to better document how it is used here. */ /* Whether relocations have been processed. */ #define reloc_done sec_flg0 static reloc_howto_type elf_howto_table[] = { HOWTO (R_XTENSA_NONE, 0, 0, 0, FALSE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_NONE", FALSE, 0, 0, FALSE), HOWTO (R_XTENSA_32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_xtensa_reloc, "R_XTENSA_32", TRUE, 0xffffffff, 0xffffffff, FALSE), /* Replace a 32-bit value with a value from the runtime linker (only used by linker-generated stub functions). The r_addend value is special: 1 means to substitute a pointer to the runtime linker's dynamic resolver function; 2 means to substitute the link map for the shared object. */ HOWTO (R_XTENSA_RTLD, 0, 2, 32, FALSE, 0, complain_overflow_dont, NULL, "R_XTENSA_RTLD", FALSE, 0, 0, FALSE), HOWTO (R_XTENSA_GLOB_DAT, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_XTENSA_GLOB_DAT", FALSE, 0, 0xffffffff, FALSE), HOWTO (R_XTENSA_JMP_SLOT, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_XTENSA_JMP_SLOT", FALSE, 0, 0xffffffff, FALSE), HOWTO (R_XTENSA_RELATIVE, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_XTENSA_RELATIVE", FALSE, 0, 0xffffffff, FALSE), HOWTO (R_XTENSA_PLT, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_xtensa_reloc, "R_XTENSA_PLT", FALSE, 0, 0xffffffff, FALSE), EMPTY_HOWTO (7), /* Old relocations for backward compatibility. */ HOWTO (R_XTENSA_OP0, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_OP0", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_OP1, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_OP1", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_OP2, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_OP2", FALSE, 0, 0, TRUE), /* Assembly auto-expansion. */ HOWTO (R_XTENSA_ASM_EXPAND, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_ASM_EXPAND", FALSE, 0, 0, TRUE), /* Relax assembly auto-expansion. */ HOWTO (R_XTENSA_ASM_SIMPLIFY, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_ASM_SIMPLIFY", FALSE, 0, 0, TRUE), EMPTY_HOWTO (13), HOWTO (R_XTENSA_32_PCREL, 0, 2, 32, TRUE, 0, complain_overflow_bitfield, bfd_elf_xtensa_reloc, "R_XTENSA_32_PCREL", FALSE, 0, 0xffffffff, TRUE), /* GNU extension to record C++ vtable hierarchy. */ HOWTO (R_XTENSA_GNU_VTINHERIT, 0, 2, 0, FALSE, 0, complain_overflow_dont, NULL, "R_XTENSA_GNU_VTINHERIT", FALSE, 0, 0, FALSE), /* GNU extension to record C++ vtable member usage. */ HOWTO (R_XTENSA_GNU_VTENTRY, 0, 2, 0, FALSE, 0, complain_overflow_dont, _bfd_elf_rel_vtable_reloc_fn, "R_XTENSA_GNU_VTENTRY", FALSE, 0, 0, FALSE), /* Relocations for supporting difference of symbols. */ HOWTO (R_XTENSA_DIFF8, 0, 0, 8, FALSE, 0, complain_overflow_bitfield, bfd_elf_xtensa_reloc, "R_XTENSA_DIFF8", FALSE, 0, 0xff, FALSE), HOWTO (R_XTENSA_DIFF16, 0, 1, 16, FALSE, 0, complain_overflow_bitfield, bfd_elf_xtensa_reloc, "R_XTENSA_DIFF16", FALSE, 0, 0xffff, FALSE), HOWTO (R_XTENSA_DIFF32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_xtensa_reloc, "R_XTENSA_DIFF32", FALSE, 0, 0xffffffff, FALSE), /* General immediate operand relocations. */ HOWTO (R_XTENSA_SLOT0_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT0_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT1_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT1_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT2_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT2_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT3_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT3_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT4_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT4_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT5_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT5_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT6_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT6_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT7_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT7_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT8_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT8_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT9_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT9_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT10_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT10_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT11_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT11_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT12_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT12_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT13_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT13_OP", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT14_OP, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT14_OP", FALSE, 0, 0, TRUE), /* "Alternate" relocations. The meaning of these is opcode-specific. */ HOWTO (R_XTENSA_SLOT0_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT0_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT1_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT1_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT2_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT2_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT3_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT3_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT4_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT4_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT5_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT5_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT6_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT6_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT7_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT7_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT8_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT8_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT9_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT9_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT10_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT10_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT11_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT11_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT12_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT12_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT13_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT13_ALT", FALSE, 0, 0, TRUE), HOWTO (R_XTENSA_SLOT14_ALT, 0, 0, 0, TRUE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_SLOT14_ALT", FALSE, 0, 0, TRUE), /* TLS relocations. */ HOWTO (R_XTENSA_TLSDESC_FN, 0, 2, 32, FALSE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_TLSDESC_FN", FALSE, 0, 0xffffffff, FALSE), HOWTO (R_XTENSA_TLSDESC_ARG, 0, 2, 32, FALSE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_TLSDESC_ARG", FALSE, 0, 0xffffffff, FALSE), HOWTO (R_XTENSA_TLS_DTPOFF, 0, 2, 32, FALSE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_TLS_DTPOFF", FALSE, 0, 0xffffffff, FALSE), HOWTO (R_XTENSA_TLS_TPOFF, 0, 2, 32, FALSE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_TLS_TPOFF", FALSE, 0, 0xffffffff, FALSE), HOWTO (R_XTENSA_TLS_FUNC, 0, 0, 0, FALSE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_TLS_FUNC", FALSE, 0, 0, FALSE), HOWTO (R_XTENSA_TLS_ARG, 0, 0, 0, FALSE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_TLS_ARG", FALSE, 0, 0, FALSE), HOWTO (R_XTENSA_TLS_CALL, 0, 0, 0, FALSE, 0, complain_overflow_dont, bfd_elf_xtensa_reloc, "R_XTENSA_TLS_CALL", FALSE, 0, 0, FALSE), }; #if DEBUG_GEN_RELOC #define TRACE(str) \ fprintf (stderr, "Xtensa bfd reloc lookup %d (%s)\n", code, str) #else #define TRACE(str) #endif static reloc_howto_type * elf_xtensa_reloc_type_lookup (bfd *abfd ATTRIBUTE_UNUSED, bfd_reloc_code_real_type code) { switch (code) { case BFD_RELOC_NONE: TRACE ("BFD_RELOC_NONE"); return &elf_howto_table[(unsigned) R_XTENSA_NONE ]; case BFD_RELOC_32: TRACE ("BFD_RELOC_32"); return &elf_howto_table[(unsigned) R_XTENSA_32 ]; case BFD_RELOC_32_PCREL: TRACE ("BFD_RELOC_32_PCREL"); return &elf_howto_table[(unsigned) R_XTENSA_32_PCREL ]; case BFD_RELOC_XTENSA_DIFF8: TRACE ("BFD_RELOC_XTENSA_DIFF8"); return &elf_howto_table[(unsigned) R_XTENSA_DIFF8 ]; case BFD_RELOC_XTENSA_DIFF16: TRACE ("BFD_RELOC_XTENSA_DIFF16"); return &elf_howto_table[(unsigned) R_XTENSA_DIFF16 ]; case BFD_RELOC_XTENSA_DIFF32: TRACE ("BFD_RELOC_XTENSA_DIFF32"); return &elf_howto_table[(unsigned) R_XTENSA_DIFF32 ]; case BFD_RELOC_XTENSA_RTLD: TRACE ("BFD_RELOC_XTENSA_RTLD"); return &elf_howto_table[(unsigned) R_XTENSA_RTLD ]; case BFD_RELOC_XTENSA_GLOB_DAT: TRACE ("BFD_RELOC_XTENSA_GLOB_DAT"); return &elf_howto_table[(unsigned) R_XTENSA_GLOB_DAT ]; case BFD_RELOC_XTENSA_JMP_SLOT: TRACE ("BFD_RELOC_XTENSA_JMP_SLOT"); return &elf_howto_table[(unsigned) R_XTENSA_JMP_SLOT ]; case BFD_RELOC_XTENSA_RELATIVE: TRACE ("BFD_RELOC_XTENSA_RELATIVE"); return &elf_howto_table[(unsigned) R_XTENSA_RELATIVE ]; case BFD_RELOC_XTENSA_PLT: TRACE ("BFD_RELOC_XTENSA_PLT"); return &elf_howto_table[(unsigned) R_XTENSA_PLT ]; case BFD_RELOC_XTENSA_OP0: TRACE ("BFD_RELOC_XTENSA_OP0"); return &elf_howto_table[(unsigned) R_XTENSA_OP0 ]; case BFD_RELOC_XTENSA_OP1: TRACE ("BFD_RELOC_XTENSA_OP1"); return &elf_howto_table[(unsigned) R_XTENSA_OP1 ]; case BFD_RELOC_XTENSA_OP2: TRACE ("BFD_RELOC_XTENSA_OP2"); return &elf_howto_table[(unsigned) R_XTENSA_OP2 ]; case BFD_RELOC_XTENSA_ASM_EXPAND: TRACE ("BFD_RELOC_XTENSA_ASM_EXPAND"); return &elf_howto_table[(unsigned) R_XTENSA_ASM_EXPAND ]; case BFD_RELOC_XTENSA_ASM_SIMPLIFY: TRACE ("BFD_RELOC_XTENSA_ASM_SIMPLIFY"); return &elf_howto_table[(unsigned) R_XTENSA_ASM_SIMPLIFY ]; case BFD_RELOC_VTABLE_INHERIT: TRACE ("BFD_RELOC_VTABLE_INHERIT"); return &elf_howto_table[(unsigned) R_XTENSA_GNU_VTINHERIT ]; case BFD_RELOC_VTABLE_ENTRY: TRACE ("BFD_RELOC_VTABLE_ENTRY"); return &elf_howto_table[(unsigned) R_XTENSA_GNU_VTENTRY ]; case BFD_RELOC_XTENSA_TLSDESC_FN: TRACE ("BFD_RELOC_XTENSA_TLSDESC_FN"); return &elf_howto_table[(unsigned) R_XTENSA_TLSDESC_FN ]; case BFD_RELOC_XTENSA_TLSDESC_ARG: TRACE ("BFD_RELOC_XTENSA_TLSDESC_ARG"); return &elf_howto_table[(unsigned) R_XTENSA_TLSDESC_ARG ]; case BFD_RELOC_XTENSA_TLS_DTPOFF: TRACE ("BFD_RELOC_XTENSA_TLS_DTPOFF"); return &elf_howto_table[(unsigned) R_XTENSA_TLS_DTPOFF ]; case BFD_RELOC_XTENSA_TLS_TPOFF: TRACE ("BFD_RELOC_XTENSA_TLS_TPOFF"); return &elf_howto_table[(unsigned) R_XTENSA_TLS_TPOFF ]; case BFD_RELOC_XTENSA_TLS_FUNC: TRACE ("BFD_RELOC_XTENSA_TLS_FUNC"); return &elf_howto_table[(unsigned) R_XTENSA_TLS_FUNC ]; case BFD_RELOC_XTENSA_TLS_ARG: TRACE ("BFD_RELOC_XTENSA_TLS_ARG"); return &elf_howto_table[(unsigned) R_XTENSA_TLS_ARG ]; case BFD_RELOC_XTENSA_TLS_CALL: TRACE ("BFD_RELOC_XTENSA_TLS_CALL"); return &elf_howto_table[(unsigned) R_XTENSA_TLS_CALL ]; default: if (code >= BFD_RELOC_XTENSA_SLOT0_OP && code <= BFD_RELOC_XTENSA_SLOT14_OP) { unsigned n = (R_XTENSA_SLOT0_OP + (code - BFD_RELOC_XTENSA_SLOT0_OP)); return &elf_howto_table[n]; } if (code >= BFD_RELOC_XTENSA_SLOT0_ALT && code <= BFD_RELOC_XTENSA_SLOT14_ALT) { unsigned n = (R_XTENSA_SLOT0_ALT + (code - BFD_RELOC_XTENSA_SLOT0_ALT)); return &elf_howto_table[n]; } break; } TRACE ("Unknown"); return NULL; } static reloc_howto_type * elf_xtensa_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED, const char *r_name) { unsigned int i; for (i = 0; i < sizeof (elf_howto_table) / sizeof (elf_howto_table[0]); i++) if (elf_howto_table[i].name != NULL && strcasecmp (elf_howto_table[i].name, r_name) == 0) return &elf_howto_table[i]; return NULL; } /* Given an ELF "rela" relocation, find the corresponding howto and record it in the BFD internal arelent representation of the relocation. */ static void elf_xtensa_info_to_howto_rela (bfd *abfd ATTRIBUTE_UNUSED, arelent *cache_ptr, Elf_Internal_Rela *dst) { unsigned int r_type = ELF32_R_TYPE (dst->r_info); BFD_ASSERT (r_type < (unsigned int) R_XTENSA_max); cache_ptr->howto = &elf_howto_table[r_type]; } /* Functions for the Xtensa ELF linker. */ /* The name of the dynamic interpreter. This is put in the .interp section. */ #define ELF_DYNAMIC_INTERPRETER "/lib/ld.so" /* The size in bytes of an entry in the procedure linkage table. (This does _not_ include the space for the literals associated with the PLT entry.) */ #define PLT_ENTRY_SIZE 16 /* For _really_ large PLTs, we may need to alternate between literals and code to keep the literals within the 256K range of the L32R instructions in the code. It's unlikely that anyone would ever need such a big PLT, but an arbitrary limit on the PLT size would be bad. Thus, we split the PLT into chunks. Since there's very little overhead (2 extra literals) for each chunk, the chunk size is kept small so that the code for handling multiple chunks get used and tested regularly. With 254 entries, there are 1K of literals for each chunk, and that seems like a nice round number. */ #define PLT_ENTRIES_PER_CHUNK 254 /* PLT entries are actually used as stub functions for lazy symbol resolution. Once the symbol is resolved, the stub function is never invoked. Note: the 32-byte frame size used here cannot be changed without a corresponding change in the runtime linker. */ static const bfd_byte elf_xtensa_be_plt_entry[PLT_ENTRY_SIZE] = { 0x6c, 0x10, 0x04, /* entry sp, 32 */ 0x18, 0x00, 0x00, /* l32r a8, [got entry for rtld's resolver] */ 0x1a, 0x00, 0x00, /* l32r a10, [got entry for rtld's link map] */ 0x1b, 0x00, 0x00, /* l32r a11, [literal for reloc index] */ 0x0a, 0x80, 0x00, /* jx a8 */ 0 /* unused */ }; static const bfd_byte elf_xtensa_le_plt_entry[PLT_ENTRY_SIZE] = { 0x36, 0x41, 0x00, /* entry sp, 32 */ 0x81, 0x00, 0x00, /* l32r a8, [got entry for rtld's resolver] */ 0xa1, 0x00, 0x00, /* l32r a10, [got entry for rtld's link map] */ 0xb1, 0x00, 0x00, /* l32r a11, [literal for reloc index] */ 0xa0, 0x08, 0x00, /* jx a8 */ 0 /* unused */ }; /* The size of the thread control block. */ #define TCB_SIZE 8 struct elf_xtensa_link_hash_entry { struct elf_link_hash_entry elf; bfd_signed_vma tlsfunc_refcount; #define GOT_UNKNOWN 0 #define GOT_NORMAL 1 #define GOT_TLS_GD 2 /* global or local dynamic */ #define GOT_TLS_IE 4 /* initial or local exec */ #define GOT_TLS_ANY (GOT_TLS_GD | GOT_TLS_IE) unsigned char tls_type; }; #define elf_xtensa_hash_entry(ent) ((struct elf_xtensa_link_hash_entry *)(ent)) struct elf_xtensa_obj_tdata { struct elf_obj_tdata root; /* tls_type for each local got entry. */ char *local_got_tls_type; bfd_signed_vma *local_tlsfunc_refcounts; }; #define elf_xtensa_tdata(abfd) \ ((struct elf_xtensa_obj_tdata *) (abfd)->tdata.any) #define elf_xtensa_local_got_tls_type(abfd) \ (elf_xtensa_tdata (abfd)->local_got_tls_type) #define elf_xtensa_local_tlsfunc_refcounts(abfd) \ (elf_xtensa_tdata (abfd)->local_tlsfunc_refcounts) #define is_xtensa_elf(bfd) \ (bfd_get_flavour (bfd) == bfd_target_elf_flavour \ && elf_tdata (bfd) != NULL \ && elf_object_id (bfd) == XTENSA_ELF_DATA) static bfd_boolean elf_xtensa_mkobject (bfd *abfd) { return bfd_elf_allocate_object (abfd, sizeof (struct elf_xtensa_obj_tdata), XTENSA_ELF_DATA); } /* Xtensa ELF linker hash table. */ struct elf_xtensa_link_hash_table { struct elf_link_hash_table elf; /* Short-cuts to get to dynamic linker sections. */ asection *sgot; asection *sgotplt; asection *srelgot; asection *splt; asection *srelplt; asection *sgotloc; asection *spltlittbl; /* Total count of PLT relocations seen during check_relocs. The actual PLT code must be split into multiple sections and all the sections have to be created before size_dynamic_sections, where we figure out the exact number of PLT entries that will be needed. It is OK if this count is an overestimate, e.g., some relocations may be removed by GC. */ int plt_reloc_count; struct elf_xtensa_link_hash_entry *tlsbase; }; /* Get the Xtensa ELF linker hash table from a link_info structure. */ #define elf_xtensa_hash_table(p) \ (elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) \ == XTENSA_ELF_DATA ? ((struct elf_xtensa_link_hash_table *) ((p)->hash)) : NULL) /* Create an entry in an Xtensa ELF linker hash table. */ static struct bfd_hash_entry * elf_xtensa_link_hash_newfunc (struct bfd_hash_entry *entry, struct bfd_hash_table *table, const char *string) { /* Allocate the structure if it has not already been allocated by a subclass. */ if (entry == NULL) { entry = bfd_hash_allocate (table, sizeof (struct elf_xtensa_link_hash_entry)); if (entry == NULL) return entry; } /* Call the allocation method of the superclass. */ entry = _bfd_elf_link_hash_newfunc (entry, table, string); if (entry != NULL) { struct elf_xtensa_link_hash_entry *eh = elf_xtensa_hash_entry (entry); eh->tlsfunc_refcount = 0; eh->tls_type = GOT_UNKNOWN; } return entry; } /* Create an Xtensa ELF linker hash table. */ static struct bfd_link_hash_table * elf_xtensa_link_hash_table_create (bfd *abfd) { struct elf_link_hash_entry *tlsbase; struct elf_xtensa_link_hash_table *ret; bfd_size_type amt = sizeof (struct elf_xtensa_link_hash_table); ret = bfd_malloc (amt); if (ret == NULL) return NULL; if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd, elf_xtensa_link_hash_newfunc, sizeof (struct elf_xtensa_link_hash_entry), XTENSA_ELF_DATA)) { free (ret); return NULL; } ret->sgot = NULL; ret->sgotplt = NULL; ret->srelgot = NULL; ret->splt = NULL; ret->srelplt = NULL; ret->sgotloc = NULL; ret->spltlittbl = NULL; ret->plt_reloc_count = 0; /* Create a hash entry for "_TLS_MODULE_BASE_" to speed up checking for it later. */ tlsbase = elf_link_hash_lookup (&ret->elf, "_TLS_MODULE_BASE_", TRUE, FALSE, FALSE); tlsbase->root.type = bfd_link_hash_new; tlsbase->root.u.undef.abfd = NULL; tlsbase->non_elf = 0; ret->tlsbase = elf_xtensa_hash_entry (tlsbase); ret->tlsbase->tls_type = GOT_UNKNOWN; return &ret->elf.root; } /* Copy the extra info we tack onto an elf_link_hash_entry. */ static void elf_xtensa_copy_indirect_symbol (struct bfd_link_info *info, struct elf_link_hash_entry *dir, struct elf_link_hash_entry *ind) { struct elf_xtensa_link_hash_entry *edir, *eind; edir = elf_xtensa_hash_entry (dir); eind = elf_xtensa_hash_entry (ind); if (ind->root.type == bfd_link_hash_indirect) { edir->tlsfunc_refcount += eind->tlsfunc_refcount; eind->tlsfunc_refcount = 0; if (dir->got.refcount <= 0) { edir->tls_type = eind->tls_type; eind->tls_type = GOT_UNKNOWN; } } _bfd_elf_link_hash_copy_indirect (info, dir, ind); } static inline bfd_boolean elf_xtensa_dynamic_symbol_p (struct elf_link_hash_entry *h, struct bfd_link_info *info) { /* Check if we should do dynamic things to this symbol. The "ignore_protected" argument need not be set, because Xtensa code does not require special handling of STV_PROTECTED to make function pointer comparisons work properly. The PLT addresses are never used for function pointers. */ return _bfd_elf_dynamic_symbol_p (h, info, 0); } static int property_table_compare (const void *ap, const void *bp) { const property_table_entry *a = (const property_table_entry *) ap; const property_table_entry *b = (const property_table_entry *) bp; if (a->address == b->address) { if (a->size != b->size) return (a->size - b->size); if ((a->flags & XTENSA_PROP_ALIGN) != (b->flags & XTENSA_PROP_ALIGN)) return ((b->flags & XTENSA_PROP_ALIGN) - (a->flags & XTENSA_PROP_ALIGN)); if ((a->flags & XTENSA_PROP_ALIGN) && (GET_XTENSA_PROP_ALIGNMENT (a->flags) != GET_XTENSA_PROP_ALIGNMENT (b->flags))) return (GET_XTENSA_PROP_ALIGNMENT (a->flags) - GET_XTENSA_PROP_ALIGNMENT (b->flags)); if ((a->flags & XTENSA_PROP_UNREACHABLE) != (b->flags & XTENSA_PROP_UNREACHABLE)) return ((b->flags & XTENSA_PROP_UNREACHABLE) - (a->flags & XTENSA_PROP_UNREACHABLE)); return (a->flags - b->flags); } return (a->address - b->address); } static int property_table_matches (const void *ap, const void *bp) { const property_table_entry *a = (const property_table_entry *) ap; const property_table_entry *b = (const property_table_entry *) bp; /* Check if one entry overlaps with the other. */ if ((b->address >= a->address && b->address < (a->address + a->size)) || (a->address >= b->address && a->address < (b->address + b->size))) return 0; return (a->address - b->address); } /* Get the literal table or property table entries for the given section. Sets TABLE_P and returns the number of entries. On error, returns a negative value. */ static int xtensa_read_table_entries (bfd *abfd, asection *section, property_table_entry **table_p, const char *sec_name, bfd_boolean output_addr) { asection *table_section; bfd_size_type table_size = 0; bfd_byte *table_data; property_table_entry *blocks; int blk, block_count; bfd_size_type num_records; Elf_Internal_Rela *internal_relocs, *irel, *rel_end; bfd_vma section_addr, off; flagword predef_flags; bfd_size_type table_entry_size, section_limit; if (!section || !(section->flags & SEC_ALLOC) || (section->flags & SEC_DEBUGGING)) { *table_p = NULL; return 0; } table_section = xtensa_get_property_section (section, sec_name); if (table_section) table_size = table_section->size; if (table_size == 0) { *table_p = NULL; return 0; } predef_flags = xtensa_get_property_predef_flags (table_section); table_entry_size = 12; if (predef_flags) table_entry_size -= 4; num_records = table_size / table_entry_size; table_data = retrieve_contents (abfd, table_section, TRUE); blocks = (property_table_entry *) bfd_malloc (num_records * sizeof (property_table_entry)); block_count = 0; if (output_addr) section_addr = section->output_section->vma + section->output_offset; else section_addr = section->vma; internal_relocs = retrieve_internal_relocs (abfd, table_section, TRUE); if (internal_relocs && !table_section->reloc_done) { qsort (internal_relocs, table_section->reloc_count, sizeof (Elf_Internal_Rela), internal_reloc_compare); irel = internal_relocs; } else irel = NULL; section_limit = bfd_get_section_limit (abfd, section); rel_end = internal_relocs + table_section->reloc_count; for (off = 0; off < table_size; off += table_entry_size) { bfd_vma address = bfd_get_32 (abfd, table_data + off); /* Skip any relocations before the current offset. This should help avoid confusion caused by unexpected relocations for the preceding table entry. */ while (irel && (irel->r_offset < off || (irel->r_offset == off && ELF32_R_TYPE (irel->r_info) == R_XTENSA_NONE))) { irel += 1; if (irel >= rel_end) irel = 0; } if (irel && irel->r_offset == off) { bfd_vma sym_off; unsigned long r_symndx = ELF32_R_SYM (irel->r_info); BFD_ASSERT (ELF32_R_TYPE (irel->r_info) == R_XTENSA_32); if (get_elf_r_symndx_section (abfd, r_symndx) != section) continue; sym_off = get_elf_r_symndx_offset (abfd, r_symndx); BFD_ASSERT (sym_off == 0); address += (section_addr + sym_off + irel->r_addend); } else { if (address < section_addr || address >= section_addr + section_limit) continue; } blocks[block_count].address = address; blocks[block_count].size = bfd_get_32 (abfd, table_data + off + 4); if (predef_flags) blocks[block_count].flags = predef_flags; else blocks[block_count].flags = bfd_get_32 (abfd, table_data + off + 8); block_count++; } release_contents (table_section, table_data); release_internal_relocs (table_section, internal_relocs); if (block_count > 0) { /* Now sort them into address order for easy reference. */ qsort (blocks, block_count, sizeof (property_table_entry), property_table_compare); /* Check that the table contents are valid. Problems may occur, for example, if an unrelocated object file is stripped. */ for (blk = 1; blk < block_count; blk++) { /* The only circumstance where two entries may legitimately have the same address is when one of them is a zero-size placeholder to mark a place where fill can be inserted. The zero-size entry should come first. */ if (blocks[blk - 1].address == blocks[blk].address && blocks[blk - 1].size != 0) { (*_bfd_error_handler) (_("%B(%A): invalid property table"), abfd, section); bfd_set_error (bfd_error_bad_value); free (blocks); return -1; } } } *table_p = blocks; return block_count; } static property_table_entry * elf_xtensa_find_property_entry (property_table_entry *property_table, int property_table_size, bfd_vma addr) { property_table_entry entry; property_table_entry *rv; if (property_table_size == 0) return NULL; entry.address = addr; entry.size = 1; entry.flags = 0; rv = bsearch (&entry, property_table, property_table_size, sizeof (property_table_entry), property_table_matches); return rv; } static bfd_boolean elf_xtensa_in_literal_pool (property_table_entry *lit_table, int lit_table_size, bfd_vma addr) { if (elf_xtensa_find_property_entry (lit_table, lit_table_size, addr)) return TRUE; return FALSE; } /* Look through the relocs for a section during the first phase, and calculate needed space in the dynamic reloc sections. */ static bfd_boolean elf_xtensa_check_relocs (bfd *abfd, struct bfd_link_info *info, asection *sec, const Elf_Internal_Rela *relocs) { struct elf_xtensa_link_hash_table *htab; Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes; const Elf_Internal_Rela *rel; const Elf_Internal_Rela *rel_end; if (info->relocatable || (sec->flags & SEC_ALLOC) == 0) return TRUE; BFD_ASSERT (is_xtensa_elf (abfd)); htab = elf_xtensa_hash_table (info); if (htab == NULL) return FALSE; symtab_hdr = &elf_tdata (abfd)->symtab_hdr; sym_hashes = elf_sym_hashes (abfd); rel_end = relocs + sec->reloc_count; for (rel = relocs; rel < rel_end; rel++) { unsigned int r_type; unsigned long r_symndx; struct elf_link_hash_entry *h = NULL; struct elf_xtensa_link_hash_entry *eh; int tls_type, old_tls_type; bfd_boolean is_got = FALSE; bfd_boolean is_plt = FALSE; bfd_boolean is_tlsfunc = FALSE; r_symndx = ELF32_R_SYM (rel->r_info); r_type = ELF32_R_TYPE (rel->r_info); if (r_symndx >= NUM_SHDR_ENTRIES (symtab_hdr)) { (*_bfd_error_handler) (_("%B: bad symbol index: %d"), abfd, r_symndx); return FALSE; } if (r_symndx >= symtab_hdr->sh_info) { h = sym_hashes[r_symndx - symtab_hdr->sh_info]; while (h->root.type == bfd_link_hash_indirect || h->root.type == bfd_link_hash_warning) h = (struct elf_link_hash_entry *) h->root.u.i.link; } eh = elf_xtensa_hash_entry (h); switch (r_type) { case R_XTENSA_TLSDESC_FN: if (info->shared) { tls_type = GOT_TLS_GD; is_got = TRUE; is_tlsfunc = TRUE; } else tls_type = GOT_TLS_IE; break; case R_XTENSA_TLSDESC_ARG: if (info->shared) { tls_type = GOT_TLS_GD; is_got = TRUE; } else { tls_type = GOT_TLS_IE; if (h && elf_xtensa_hash_entry (h) != htab->tlsbase) is_got = TRUE; } break; case R_XTENSA_TLS_DTPOFF: if (info->shared) tls_type = GOT_TLS_GD; else tls_type = GOT_TLS_IE; break; case R_XTENSA_TLS_TPOFF: tls_type = GOT_TLS_IE; if (info->shared) info->flags |= DF_STATIC_TLS; if (info->shared || h) is_got = TRUE; break; case R_XTENSA_32: tls_type = GOT_NORMAL; is_got = TRUE; break; case R_XTENSA_PLT: tls_type = GOT_NORMAL; is_plt = TRUE; break; case R_XTENSA_GNU_VTINHERIT: /* This relocation describes the C++ object vtable hierarchy. Reconstruct it for later use during GC. */ if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset)) return FALSE; continue; case R_XTENSA_GNU_VTENTRY: /* This relocation describes which C++ vtable entries are actually used. Record for later use during GC. */ BFD_ASSERT (h != NULL); if (h != NULL && !bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend)) return FALSE; continue; default: /* Nothing to do for any other relocations. */ continue; } if (h) { if (is_plt) { if (h->plt.refcount <= 0) { h->needs_plt = 1; h->plt.refcount = 1; } else h->plt.refcount += 1; /* Keep track of the total PLT relocation count even if we don't yet know whether the dynamic sections will be created. */ htab->plt_reloc_count += 1; if (elf_hash_table (info)->dynamic_sections_created) { if (! add_extra_plt_sections (info, htab->plt_reloc_count)) return FALSE; } } else if (is_got) { if (h->got.refcount <= 0) h->got.refcount = 1; else h->got.refcount += 1; } if (is_tlsfunc) eh->tlsfunc_refcount += 1; old_tls_type = eh->tls_type; } else { /* Allocate storage the first time. */ if (elf_local_got_refcounts (abfd) == NULL) { bfd_size_type size = symtab_hdr->sh_info; void *mem; mem = bfd_zalloc (abfd, size * sizeof (bfd_signed_vma)); if (mem == NULL) return FALSE; elf_local_got_refcounts (abfd) = (bfd_signed_vma *) mem; mem = bfd_zalloc (abfd, size); if (mem == NULL) return FALSE; elf_xtensa_local_got_tls_type (abfd) = (char *) mem; mem = bfd_zalloc (abfd, size * sizeof (bfd_signed_vma)); if (mem == NULL) return FALSE; elf_xtensa_local_tlsfunc_refcounts (abfd) = (bfd_signed_vma *) mem; } /* This is a global offset table entry for a local symbol. */ if (is_got || is_plt) elf_local_got_refcounts (abfd) [r_symndx] += 1; if (is_tlsfunc) elf_xtensa_local_tlsfunc_refcounts (abfd) [r_symndx] += 1; old_tls_type = elf_xtensa_local_got_tls_type (abfd) [r_symndx]; } if ((old_tls_type & GOT_TLS_IE) && (tls_type & GOT_TLS_IE)) tls_type |= old_tls_type; /* If a TLS symbol is accessed using IE at least once, there is no point to use a dynamic model for it. */ else if (old_tls_type != tls_type && old_tls_type != GOT_UNKNOWN && ((old_tls_type & GOT_TLS_GD) == 0 || (tls_type & GOT_TLS_IE) == 0)) { if ((old_tls_type & GOT_TLS_IE) && (tls_type & GOT_TLS_GD)) tls_type = old_tls_type; else if ((old_tls_type & GOT_TLS_GD) && (tls_type & GOT_TLS_GD)) tls_type |= old_tls_type; else { (*_bfd_error_handler) (_("%B: `%s' accessed both as normal and thread local symbol"), abfd, h ? h->root.root.string : "<local>"); return FALSE; } } if (old_tls_type != tls_type) { if (eh) eh->tls_type = tls_type; else elf_xtensa_local_got_tls_type (abfd) [r_symndx] = tls_type; } } return TRUE; } static void elf_xtensa_make_sym_local (struct bfd_link_info *info, struct elf_link_hash_entry *h) { if (info->shared) { if (h->plt.refcount > 0) { /* For shared objects, there's no need for PLT entries for local symbols (use RELATIVE relocs instead of JMP_SLOT relocs). */ if (h->got.refcount < 0) h->got.refcount = 0; h->got.refcount += h->plt.refcount; h->plt.refcount = 0; } } else { /* Don't need any dynamic relocations at all. */ h->plt.refcount = 0; h->got.refcount = 0; } } static void elf_xtensa_hide_symbol (struct bfd_link_info *info, struct elf_link_hash_entry *h, bfd_boolean force_local) { /* For a shared link, move the plt refcount to the got refcount to leave space for RELATIVE relocs. */ elf_xtensa_make_sym_local (info, h); _bfd_elf_link_hash_hide_symbol (info, h, force_local); } /* Return the section that should be marked against GC for a given relocation. */ static asection * elf_xtensa_gc_mark_hook (asection *sec, struct bfd_link_info *info, Elf_Internal_Rela *rel, struct elf_link_hash_entry *h, Elf_Internal_Sym *sym) { /* Property sections are marked "KEEP" in the linker scripts, but they should not cause other sections to be marked. (This approach relies on elf_xtensa_discard_info to remove property table entries that describe discarded sections. Alternatively, it might be more efficient to avoid using "KEEP" in the linker scripts and instead use the gc_mark_extra_sections hook to mark only the property sections that describe marked sections. That alternative does not work well with the current property table sections, which do not correspond one-to-one with the sections they describe, but that should be fixed someday.) */ if (xtensa_is_property_section (sec)) return NULL; if (h != NULL) switch (ELF32_R_TYPE (rel->r_info)) { case R_XTENSA_GNU_VTINHERIT: case R_XTENSA_GNU_VTENTRY: return NULL; } return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym); } /* Update the GOT & PLT entry reference counts for the section being removed. */ static bfd_boolean elf_xtensa_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info, asection *sec, const Elf_Internal_Rela *relocs) { Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes; const Elf_Internal_Rela *rel, *relend; struct elf_xtensa_link_hash_table *htab; htab = elf_xtensa_hash_table (info); if (htab == NULL) return FALSE; if (info->relocatable) return TRUE; if ((sec->flags & SEC_ALLOC) == 0) return TRUE; symtab_hdr = &elf_tdata (abfd)->symtab_hdr; sym_hashes = elf_sym_hashes (abfd); relend = relocs + sec->reloc_count; for (rel = relocs; rel < relend; rel++) { unsigned long r_symndx; unsigned int r_type; struct elf_link_hash_entry *h = NULL; struct elf_xtensa_link_hash_entry *eh; bfd_boolean is_got = FALSE; bfd_boolean is_plt = FALSE; bfd_boolean is_tlsfunc = FALSE; r_symndx = ELF32_R_SYM (rel->r_info); if (r_symndx >= symtab_hdr->sh_info) { h = sym_hashes[r_symndx - symtab_hdr->sh_info]; while (h->root.type == bfd_link_hash_indirect || h->root.type == bfd_link_hash_warning) h = (struct elf_link_hash_entry *) h->root.u.i.link; } eh = elf_xtensa_hash_entry (h); r_type = ELF32_R_TYPE (rel->r_info); switch (r_type) { case R_XTENSA_TLSDESC_FN: if (info->shared) { is_got = TRUE; is_tlsfunc = TRUE; } break; case R_XTENSA_TLSDESC_ARG: if (info->shared) is_got = TRUE; else { if (h && elf_xtensa_hash_entry (h) != htab->tlsbase) is_got = TRUE; } break; case R_XTENSA_TLS_TPOFF: if (info->shared || h) is_got = TRUE; break; case R_XTENSA_32: is_got = TRUE; break; case R_XTENSA_PLT: is_plt = TRUE; break; default: continue; } if (h) { if (is_plt) { if (h->plt.refcount > 0) h->plt.refcount--; } else if (is_got) { if (h->got.refcount > 0) h->got.refcount--; } if (is_tlsfunc) { if (eh->tlsfunc_refcount > 0) eh->tlsfunc_refcount--; } } else { if (is_got || is_plt) { bfd_signed_vma *got_refcount = &elf_local_got_refcounts (abfd) [r_symndx]; if (*got_refcount > 0) *got_refcount -= 1; } if (is_tlsfunc) { bfd_signed_vma *tlsfunc_refcount = &elf_xtensa_local_tlsfunc_refcounts (abfd) [r_symndx]; if (*tlsfunc_refcount > 0) *tlsfunc_refcount -= 1; } } } return TRUE; } /* Create all the dynamic sections. */ static bfd_boolean elf_xtensa_create_dynamic_sections (bfd *dynobj, struct bfd_link_info *info) { struct elf_xtensa_link_hash_table *htab; flagword flags, noalloc_flags; htab = elf_xtensa_hash_table (info); if (htab == NULL) return FALSE; /* First do all the standard stuff. */ if (! _bfd_elf_create_dynamic_sections (dynobj, info)) return FALSE; htab->splt = bfd_get_section_by_name (dynobj, ".plt"); htab->srelplt = bfd_get_section_by_name (dynobj, ".rela.plt"); htab->sgot = bfd_get_section_by_name (dynobj, ".got"); htab->sgotplt = bfd_get_section_by_name (dynobj, ".got.plt"); htab->srelgot = bfd_get_section_by_name (dynobj, ".rela.got"); /* Create any extra PLT sections in case check_relocs has already been called on all the non-dynamic input files. */ if (! add_extra_plt_sections (info, htab->plt_reloc_count)) return FALSE; noalloc_flags = (SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_LINKER_CREATED | SEC_READONLY); flags = noalloc_flags | SEC_ALLOC | SEC_LOAD; /* Mark the ".got.plt" section READONLY. */ if (htab->sgotplt == NULL || ! bfd_set_section_flags (dynobj, htab->sgotplt, flags)) return FALSE; /* Create ".got.loc" (literal tables for use by dynamic linker). */ htab->sgotloc = bfd_make_section_with_flags (dynobj, ".got.loc", flags); if (htab->sgotloc == NULL || ! bfd_set_section_alignment (dynobj, htab->sgotloc, 2)) return FALSE; /* Create ".xt.lit.plt" (literal table for ".got.plt*"). */ htab->spltlittbl = bfd_make_section_with_flags (dynobj, ".xt.lit.plt", noalloc_flags); if (htab->spltlittbl == NULL || ! bfd_set_section_alignment (dynobj, htab->spltlittbl, 2)) return FALSE; return TRUE; } static bfd_boolean add_extra_plt_sections (struct bfd_link_info *info, int count) { bfd *dynobj = elf_hash_table (info)->dynobj; int chunk; /* Iterate over all chunks except 0 which uses the standard ".plt" and ".got.plt" sections. */ for (chunk = count / PLT_ENTRIES_PER_CHUNK; chunk > 0; chunk--) { char *sname; flagword flags; asection *s; /* Stop when we find a section has already been created. */ if (elf_xtensa_get_plt_section (info, chunk)) break; flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_LINKER_CREATED | SEC_READONLY); sname = (char *) bfd_malloc (10); sprintf (sname, ".plt.%u", chunk); s = bfd_make_section_with_flags (dynobj, sname, flags | SEC_CODE); if (s == NULL || ! bfd_set_section_alignment (dynobj, s, 2)) return FALSE; sname = (char *) bfd_malloc (14); sprintf (sname, ".got.plt.%u", chunk); s = bfd_make_section_with_flags (dynobj, sname, flags); if (s == NULL || ! bfd_set_section_alignment (dynobj, s, 2)) return FALSE; } return TRUE; } /* Adjust a symbol defined by a dynamic object and referenced by a regular object. The current definition is in some section of the dynamic object, but we're not including those sections. We have to change the definition to something the rest of the link can understand. */ static bfd_boolean elf_xtensa_adjust_dynamic_symbol (struct bfd_link_info *info ATTRIBUTE_UNUSED, struct elf_link_hash_entry *h) { /* If this is a weak symbol, and there is a real definition, the processor independent code will have arranged for us to see the real definition first, and we can just use the same value. */ if (h->u.weakdef) { BFD_ASSERT (h->u.weakdef->root.type == bfd_link_hash_defined || h->u.weakdef->root.type == bfd_link_hash_defweak); h->root.u.def.section = h->u.weakdef->root.u.def.section; h->root.u.def.value = h->u.weakdef->root.u.def.value; return TRUE; } /* This is a reference to a symbol defined by a dynamic object. The reference must go through the GOT, so there's no need for COPY relocs, .dynbss, etc. */ return TRUE; } static bfd_boolean elf_xtensa_allocate_dynrelocs (struct elf_link_hash_entry *h, void *arg) { struct bfd_link_info *info; struct elf_xtensa_link_hash_table *htab; struct elf_xtensa_link_hash_entry *eh = elf_xtensa_hash_entry (h); if (h->root.type == bfd_link_hash_indirect) return TRUE; if (h->root.type == bfd_link_hash_warning) h = (struct elf_link_hash_entry *) h->root.u.i.link; info = (struct bfd_link_info *) arg; htab = elf_xtensa_hash_table (info); if (htab == NULL) return FALSE; /* If we saw any use of an IE model for this symbol, we can then optimize away GOT entries for any TLSDESC_FN relocs. */ if ((eh->tls_type & GOT_TLS_IE) != 0) { BFD_ASSERT (h->got.refcount >= eh->tlsfunc_refcount); h->got.refcount -= eh->tlsfunc_refcount; } if (! elf_xtensa_dynamic_symbol_p (h, info)) elf_xtensa_make_sym_local (info, h); if (h->plt.refcount > 0) htab->srelplt->size += (h->plt.refcount * sizeof (Elf32_External_Rela)); if (h->got.refcount > 0) htab->srelgot->size += (h->got.refcount * sizeof (Elf32_External_Rela)); return TRUE; } static void elf_xtensa_allocate_local_got_size (struct bfd_link_info *info) { struct elf_xtensa_link_hash_table *htab; bfd *i; htab = elf_xtensa_hash_table (info); if (htab == NULL) return; for (i = info->input_bfds; i; i = i->link_next) { bfd_signed_vma *local_got_refcounts; bfd_size_type j, cnt; Elf_Internal_Shdr *symtab_hdr; local_got_refcounts = elf_local_got_refcounts (i); if (!local_got_refcounts) continue; symtab_hdr = &elf_tdata (i)->symtab_hdr; cnt = symtab_hdr->sh_info; for (j = 0; j < cnt; ++j) { /* If we saw any use of an IE model for this symbol, we can then optimize away GOT entries for any TLSDESC_FN relocs. */ if ((elf_xtensa_local_got_tls_type (i) [j] & GOT_TLS_IE) != 0) { bfd_signed_vma *tlsfunc_refcount = &elf_xtensa_local_tlsfunc_refcounts (i) [j]; BFD_ASSERT (local_got_refcounts[j] >= *tlsfunc_refcount); local_got_refcounts[j] -= *tlsfunc_refcount; } if (local_got_refcounts[j] > 0) htab->srelgot->size += (local_got_refcounts[j] * sizeof (Elf32_External_Rela)); } } } /* Set the sizes of the dynamic sections. */ static bfd_boolean elf_xtensa_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, struct bfd_link_info *info) { struct elf_xtensa_link_hash_table *htab; bfd *dynobj, *abfd; asection *s, *srelplt, *splt, *sgotplt, *srelgot, *spltlittbl, *sgotloc; bfd_boolean relplt, relgot; int plt_entries, plt_chunks, chunk; plt_entries = 0; plt_chunks = 0; htab = elf_xtensa_hash_table (info); if (htab == NULL) return FALSE; dynobj = elf_hash_table (info)->dynobj; if (dynobj == NULL) abort (); srelgot = htab->srelgot; srelplt = htab->srelplt; if (elf_hash_table (info)->dynamic_sections_created) { BFD_ASSERT (htab->srelgot != NULL && htab->srelplt != NULL && htab->sgot != NULL && htab->spltlittbl != NULL && htab->sgotloc != NULL); /* Set the contents of the .interp section to the interpreter. */ if (info->executable) { s = bfd_get_section_by_name (dynobj, ".interp"); if (s == NULL) abort (); s->size = sizeof ELF_DYNAMIC_INTERPRETER; s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER; } /* Allocate room for one word in ".got". */ htab->sgot->size = 4; /* Allocate space in ".rela.got" for literals that reference global symbols and space in ".rela.plt" for literals that have PLT entries. */ elf_link_hash_traverse (elf_hash_table (info), elf_xtensa_allocate_dynrelocs, (void *) info); /* If we are generating a shared object, we also need space in ".rela.got" for R_XTENSA_RELATIVE relocs for literals that reference local symbols. */ if (info->shared) elf_xtensa_allocate_local_got_size (info); /* Allocate space in ".plt" to match the size of ".rela.plt". For each PLT entry, we need the PLT code plus a 4-byte literal. For each chunk of ".plt", we also need two more 4-byte literals, two corresponding entries in ".rela.got", and an 8-byte entry in ".xt.lit.plt". */ spltlittbl = htab->spltlittbl; plt_entries = srelplt->size / sizeof (Elf32_External_Rela); plt_chunks = (plt_entries + PLT_ENTRIES_PER_CHUNK - 1) / PLT_ENTRIES_PER_CHUNK; /* Iterate over all the PLT chunks, including any extra sections created earlier because the initial count of PLT relocations was an overestimate. */ for (chunk = 0; (splt = elf_xtensa_get_plt_section (info, chunk)) != NULL; chunk++) { int chunk_entries; sgotplt = elf_xtensa_get_gotplt_section (info, chunk); BFD_ASSERT (sgotplt != NULL); if (chunk < plt_chunks - 1) chunk_entries = PLT_ENTRIES_PER_CHUNK; else if (chunk == plt_chunks - 1) chunk_entries = plt_entries - (chunk * PLT_ENTRIES_PER_CHUNK); else chunk_entries = 0; if (chunk_entries != 0) { sgotplt->size = 4 * (chunk_entries + 2); splt->size = PLT_ENTRY_SIZE * chunk_entries; srelgot->size += 2 * sizeof (Elf32_External_Rela); spltlittbl->size += 8; } else { sgotplt->size = 0; splt->size = 0; } } /* Allocate space in ".got.loc" to match the total size of all the literal tables. */ sgotloc = htab->sgotloc; sgotloc->size = spltlittbl->size; for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next) { if (abfd->flags & DYNAMIC) continue; for (s = abfd->sections; s != NULL; s = s->next) { if (! elf_discarded_section (s) && xtensa_is_littable_section (s) && s != spltlittbl) sgotloc->size += s->size; } } } /* Allocate memory for dynamic sections. */ relplt = FALSE; relgot = FALSE; for (s = dynobj->sections; s != NULL; s = s->next) { const char *name; if ((s->flags & SEC_LINKER_CREATED) == 0) continue; /* It's OK to base decisions on the section name, because none of the dynobj section names depend upon the input files. */ name = bfd_get_section_name (dynobj, s); if (CONST_STRNEQ (name, ".rela")) { if (s->size != 0) { if (strcmp (name, ".rela.plt") == 0) relplt = TRUE; else if (strcmp (name, ".rela.got") == 0) relgot = TRUE; /* We use the reloc_count field as a counter if we need to copy relocs into the output file. */ s->reloc_count = 0; } } else if (! CONST_STRNEQ (name, ".plt.") && ! CONST_STRNEQ (name, ".got.plt.") && strcmp (name, ".got") != 0 && strcmp (name, ".plt") != 0 && strcmp (name, ".got.plt") != 0 && strcmp (name, ".xt.lit.plt") != 0 && strcmp (name, ".got.loc") != 0) { /* It's not one of our sections, so don't allocate space. */ continue; } if (s->size == 0) { /* If we don't need this section, strip it from the output file. We must create the ".plt*" and ".got.plt*" sections in create_dynamic_sections and/or check_relocs based on a conservative estimate of the PLT relocation count, because the sections must be created before the linker maps input sections to output sections. The linker does that before size_dynamic_sections, where we compute the exact size of the PLT, so there may be more of these sections than are actually needed. */ s->flags |= SEC_EXCLUDE; } else if ((s->flags & SEC_HAS_CONTENTS) != 0) { /* Allocate memory for the section contents. */ s->contents = (bfd_byte *) bfd_zalloc (dynobj, s->size); if (s->contents == NULL) return FALSE; } } if (elf_hash_table (info)->dynamic_sections_created) { /* Add the special XTENSA_RTLD relocations now. The offsets won't be known until finish_dynamic_sections, but we need to get the relocs in place before they are sorted. */ for (chunk = 0; chunk < plt_chunks; chunk++) { Elf_Internal_Rela irela; bfd_byte *loc; irela.r_offset = 0; irela.r_info = ELF32_R_INFO (0, R_XTENSA_RTLD); irela.r_addend = 0; loc = (srelgot->contents + srelgot->reloc_count * sizeof (Elf32_External_Rela)); bfd_elf32_swap_reloca_out (output_bfd, &irela, loc); bfd_elf32_swap_reloca_out (output_bfd, &irela, loc + sizeof (Elf32_External_Rela)); srelgot->reloc_count += 2; } /* Add some entries to the .dynamic section. We fill in the values later, in elf_xtensa_finish_dynamic_sections, but we must add the entries now so that we get the correct size for the .dynamic section. The DT_DEBUG entry is filled in by the dynamic linker and used by the debugger. */ #define add_dynamic_entry(TAG, VAL) \ _bfd_elf_add_dynamic_entry (info, TAG, VAL) if (info->executable) { if (!add_dynamic_entry (DT_DEBUG, 0)) return FALSE; } if (relplt) { if (!add_dynamic_entry (DT_PLTRELSZ, 0) || !add_dynamic_entry (DT_PLTREL, DT_RELA) || !add_dynamic_entry (DT_JMPREL, 0)) return FALSE; } if (relgot) { if (!add_dynamic_entry (DT_RELA, 0) || !add_dynamic_entry (DT_RELASZ, 0) || !add_dynamic_entry (DT_RELAENT, sizeof (Elf32_External_Rela))) return FALSE; } if (!add_dynamic_entry (DT_PLTGOT, 0) || !add_dynamic_entry (DT_XTENSA_GOT_LOC_OFF, 0) || !add_dynamic_entry (DT_XTENSA_GOT_LOC_SZ, 0)) return FALSE; } #undef add_dynamic_entry return TRUE; } static bfd_boolean elf_xtensa_always_size_sections (bfd *output_bfd, struct bfd_link_info *info) { struct elf_xtensa_link_hash_table *htab; asection *tls_sec; htab = elf_xtensa_hash_table (info); if (htab == NULL) return FALSE; tls_sec = htab->elf.tls_sec; if (tls_sec && (htab->tlsbase->tls_type & GOT_TLS_ANY) != 0) { struct elf_link_hash_entry *tlsbase = &htab->tlsbase->elf; struct bfd_link_hash_entry *bh = &tlsbase->root; const struct elf_backend_data *bed = get_elf_backend_data (output_bfd); tlsbase->type = STT_TLS; if (!(_bfd_generic_link_add_one_symbol (info, output_bfd, "_TLS_MODULE_BASE_", BSF_LOCAL, tls_sec, 0, NULL, FALSE, bed->collect, &bh))) return FALSE; tlsbase->def_regular = 1; tlsbase->other = STV_HIDDEN; (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE); } return TRUE; } /* Return the base VMA address which should be subtracted from real addresses when resolving @dtpoff relocation. This is PT_TLS segment p_vaddr. */ static bfd_vma dtpoff_base (struct bfd_link_info *info) { /* If tls_sec is NULL, we should have signalled an error already. */ if (elf_hash_table (info)->tls_sec == NULL) return 0; return elf_hash_table (info)->tls_sec->vma; } /* Return the relocation value for @tpoff relocation if STT_TLS virtual address is ADDRESS. */ static bfd_vma tpoff (struct bfd_link_info *info, bfd_vma address) { struct elf_link_hash_table *htab = elf_hash_table (info); bfd_vma base; /* If tls_sec is NULL, we should have signalled an error already. */ if (htab->tls_sec == NULL) return 0; base = align_power ((bfd_vma) TCB_SIZE, htab->tls_sec->alignment_power); return address - htab->tls_sec->vma + base; } /* Perform the specified relocation. The instruction at (contents + address) is modified to set one operand to represent the value in "relocation". The operand position is determined by the relocation type recorded in the howto. */ #define CALL_SEGMENT_BITS (30) #define CALL_SEGMENT_SIZE (1 << CALL_SEGMENT_BITS) static bfd_reloc_status_type elf_xtensa_do_reloc (reloc_howto_type *howto, bfd *abfd, asection *input_section, bfd_vma relocation, bfd_byte *contents, bfd_vma address, bfd_boolean is_weak_undef, char **error_message) { xtensa_format fmt; xtensa_opcode opcode; xtensa_isa isa = xtensa_default_isa; static xtensa_insnbuf ibuff = NULL; static xtensa_insnbuf sbuff = NULL; bfd_vma self_address; bfd_size_type input_size; int opnd, slot; uint32 newval; if (!ibuff) { ibuff = xtensa_insnbuf_alloc (isa); sbuff = xtensa_insnbuf_alloc (isa); } input_size = bfd_get_section_limit (abfd, input_section); /* Calculate the PC address for this instruction. */ self_address = (input_section->output_section->vma + input_section->output_offset + address); switch (howto->type) { case R_XTENSA_NONE: case R_XTENSA_DIFF8: case R_XTENSA_DIFF16: case R_XTENSA_DIFF32: case R_XTENSA_TLS_FUNC: case R_XTENSA_TLS_ARG: case R_XTENSA_TLS_CALL: return bfd_reloc_ok; case R_XTENSA_ASM_EXPAND: if (!is_weak_undef) { /* Check for windowed CALL across a 1GB boundary. */ opcode = get_expanded_call_opcode (contents + address, input_size - address, 0); if (is_windowed_call_opcode (opcode)) { if ((self_address >> CALL_SEGMENT_BITS) != (relocation >> CALL_SEGMENT_BITS)) { *error_message = "windowed longcall crosses 1GB boundary; " "return may fail"; return bfd_reloc_dangerous; } } } return bfd_reloc_ok; case R_XTENSA_ASM_SIMPLIFY: { /* Convert the L32R/CALLX to CALL. */ bfd_reloc_status_type retval = elf_xtensa_do_asm_simplify (contents, address, input_size, error_message); if (retval != bfd_reloc_ok) return bfd_reloc_dangerous; /* The CALL needs to be relocated. Continue below for that part. */ address += 3; self_address += 3; howto = &elf_howto_table[(unsigned) R_XTENSA_SLOT0_OP ]; } break; case R_XTENSA_32: { bfd_vma x; x = bfd_get_32 (abfd, contents + address); x = x + relocation; bfd_put_32 (abfd, x, contents + address); } return bfd_reloc_ok; case R_XTENSA_32_PCREL: bfd_put_32 (abfd, relocation - self_address, contents + address); return bfd_reloc_ok; case R_XTENSA_PLT: case R_XTENSA_TLSDESC_FN: case R_XTENSA_TLSDESC_ARG: case R_XTENSA_TLS_DTPOFF: case R_XTENSA_TLS_TPOFF: bfd_put_32 (abfd, relocation, contents + address); return bfd_reloc_ok; } /* Only instruction slot-specific relocations handled below.... */ slot = get_relocation_slot (howto->type); if (slot == XTENSA_UNDEFINED) { *error_message = "unexpected relocation"; return bfd_reloc_dangerous; } /* Read the instruction into a buffer and decode the opcode. */ xtensa_insnbuf_from_chars (isa, ibuff, contents + address, input_size - address); fmt = xtensa_format_decode (isa, ibuff); if (fmt == XTENSA_UNDEFINED) { *error_message = "cannot decode instruction format"; return bfd_reloc_dangerous; } xtensa_format_get_slot (isa, fmt, slot, ibuff, sbuff); opcode = xtensa_opcode_decode (isa, fmt, slot, sbuff); if (opcode == XTENSA_UNDEFINED) { *error_message = "cannot decode instruction opcode"; return bfd_reloc_dangerous; } /* Check for opcode-specific "alternate" relocations. */ if (is_alt_relocation (howto->type)) { if (opcode == get_l32r_opcode ()) { /* Handle the special-case of non-PC-relative L32R instructions. */ bfd *output_bfd = input_section->output_section->owner; asection *lit4_sec = bfd_get_section_by_name (output_bfd, ".lit4"); if (!lit4_sec) { *error_message = "relocation references missing .lit4 section"; return bfd_reloc_dangerous; } self_address = ((lit4_sec->vma & ~0xfff) + 0x40000 - 3); /* -3 to compensate for do_reloc */ newval = relocation; opnd = 1; } else if (opcode == get_const16_opcode ()) { /* ALT used for high 16 bits. */ newval = relocation >> 16; opnd = 1; } else { /* No other "alternate" relocations currently defined. */ *error_message = "unexpected relocation"; return bfd_reloc_dangerous; } } else /* Not an "alternate" relocation.... */ { if (opcode == get_const16_opcode ()) { newval = relocation & 0xffff; opnd = 1; } else { /* ...normal PC-relative relocation.... */ /* Determine which operand is being relocated. */ opnd = get_relocation_opnd (opcode, howto->type); if (opnd == XTENSA_UNDEFINED) { *error_message = "unexpected relocation"; return bfd_reloc_dangerous; } if (!howto->pc_relative) { *error_message = "expected PC-relative relocation"; return bfd_reloc_dangerous; } newval = relocation; } } /* Apply the relocation. */ if (xtensa_operand_do_reloc (isa, opcode, opnd, &newval, self_address) || xtensa_operand_encode (isa, opcode, opnd, &newval) || xtensa_operand_set_field (isa, opcode, opnd, fmt, slot, sbuff, newval)) { const char *opname = xtensa_opcode_name (isa, opcode); const char *msg; msg = "cannot encode"; if (is_direct_call_opcode (opcode)) { if ((relocation & 0x3) != 0) msg = "misaligned call target"; else msg = "call target out of range"; } else if (opcode == get_l32r_opcode ()) { if ((relocation & 0x3) != 0) msg = "misaligned literal target"; else if (is_alt_relocation (howto->type)) msg = "literal target out of range (too many literals)"; else if (self_address > relocation) msg = "literal target out of range (try using text-section-literals)"; else msg = "literal placed after use"; } *error_message = vsprint_msg (opname, ": %s", strlen (msg) + 2, msg); return bfd_reloc_dangerous; } /* Check for calls across 1GB boundaries. */ if (is_direct_call_opcode (opcode) && is_windowed_call_opcode (opcode)) { if ((self_address >> CALL_SEGMENT_BITS) != (relocation >> CALL_SEGMENT_BITS)) { *error_message = "windowed call crosses 1GB boundary; return may fail"; return bfd_reloc_dangerous; } } /* Write the modified instruction back out of the buffer. */ xtensa_format_set_slot (isa, fmt, slot, ibuff, sbuff); xtensa_insnbuf_to_chars (isa, ibuff, contents + address, input_size - address); return bfd_reloc_ok; } static char * vsprint_msg (const char *origmsg, const char *fmt, int arglen, ...) { /* To reduce the size of the memory leak, we only use a single message buffer. */ static bfd_size_type alloc_size = 0; static char *message = NULL; bfd_size_type orig_len, len = 0; bfd_boolean is_append; VA_OPEN (ap, arglen); VA_FIXEDARG (ap, const char *, origmsg); is_append = (origmsg == message); orig_len = strlen (origmsg); len = orig_len + strlen (fmt) + arglen + 20; if (len > alloc_size) { message = (char *) bfd_realloc_or_free (message, len); alloc_size = len; } if (message != NULL) { if (!is_append) memcpy (message, origmsg, orig_len); vsprintf (message + orig_len, fmt, ap); } VA_CLOSE (ap); return message; } /* This function is registered as the "special_function" in the Xtensa howto for handling simplify operations. bfd_perform_relocation / bfd_install_relocation use it to perform (install) the specified relocation. Since this replaces the code in bfd_perform_relocation, it is basically an Xtensa-specific, stripped-down version of bfd_perform_relocation. */ static bfd_reloc_status_type bfd_elf_xtensa_reloc (bfd *abfd, arelent *reloc_entry, asymbol *symbol, void *data, asection *input_section, bfd *output_bfd, char **error_message) { bfd_vma relocation; bfd_reloc_status_type flag; bfd_size_type octets = reloc_entry->address * bfd_octets_per_byte (abfd); bfd_vma output_base = 0; reloc_howto_type *howto = reloc_entry->howto; asection *reloc_target_output_section; bfd_boolean is_weak_undef; if (!xtensa_default_isa) xtensa_default_isa = xtensa_isa_init (0, 0); /* ELF relocs are against symbols. If we are producing relocatable output, and the reloc is against an external symbol, the resulting reloc will also be against the same symbol. In such a case, we don't want to change anything about the way the reloc is handled, since it will all be done at final link time. This test is similar to what bfd_elf_generic_reloc does except that it lets relocs with howto->partial_inplace go through even if the addend is non-zero. (The real problem is that partial_inplace is set for XTENSA_32 relocs to begin with, but that's a long story and there's little we can do about it now....) */ if (output_bfd && (symbol->flags & BSF_SECTION_SYM) == 0) { reloc_entry->address += input_section->output_offset; return bfd_reloc_ok; } /* Is the address of the relocation really within the section? */ if (reloc_entry->address > bfd_get_section_limit (abfd, input_section)) return bfd_reloc_outofrange; /* Work out which section the relocation is targeted at and the initial relocation command value. */ /* Get symbol value. (Common symbols are special.) */ if (bfd_is_com_section (symbol->section)) relocation = 0; else relocation = symbol->value; reloc_target_output_section = symbol->section->output_section; /* Convert input-section-relative symbol value to absolute. */ if ((output_bfd && !howto->partial_inplace) || reloc_target_output_section == NULL) output_base = 0; else output_base = reloc_target_output_section->vma; relocation += output_base + symbol->section->output_offset; /* Add in supplied addend. */ relocation += reloc_entry->addend; /* Here the variable relocation holds the final address of the symbol we are relocating against, plus any addend. */ if (output_bfd) { if (!howto->partial_inplace) { /* This is a partial relocation, and we want to apply the relocation to the reloc entry rather than the raw data. Everything except relocations against section symbols has already been handled above. */ BFD_ASSERT (symbol->flags & BSF_SECTION_SYM); reloc_entry->addend = relocation; reloc_entry->address += input_section->output_offset; return bfd_reloc_ok; } else { reloc_entry->address += input_section->output_offset; reloc_entry->addend = 0; } } is_weak_undef = (bfd_is_und_section (symbol->section) && (symbol->flags & BSF_WEAK) != 0); flag = elf_xtensa_do_reloc (howto, abfd, input_section, relocation, (bfd_byte *) data, (bfd_vma) octets, is_weak_undef, error_message); if (flag == bfd_reloc_dangerous) { /* Add the symbol name to the error message. */ if (! *error_message) *error_message = ""; *error_message = vsprint_msg (*error_message, ": (%s + 0x%lx)", strlen (symbol->name) + 17, symbol->name, (unsigned long) reloc_entry->addend); } return flag; } /* Set up an entry in the procedure linkage table. */ static bfd_vma elf_xtensa_create_plt_entry (struct bfd_link_info *info, bfd *output_bfd, unsigned reloc_index) { asection *splt, *sgotplt; bfd_vma plt_base, got_base; bfd_vma code_offset, lit_offset; int chunk; chunk = reloc_index / PLT_ENTRIES_PER_CHUNK; splt = elf_xtensa_get_plt_section (info, chunk); sgotplt = elf_xtensa_get_gotplt_section (info, chunk); BFD_ASSERT (splt != NULL && sgotplt != NULL); plt_base = splt->output_section->vma + splt->output_offset; got_base = sgotplt->output_section->vma + sgotplt->output_offset; lit_offset = 8 + (reloc_index % PLT_ENTRIES_PER_CHUNK) * 4; code_offset = (reloc_index % PLT_ENTRIES_PER_CHUNK) * PLT_ENTRY_SIZE; /* Fill in the literal entry. This is the offset of the dynamic relocation entry. */ bfd_put_32 (output_bfd, reloc_index * sizeof (Elf32_External_Rela), sgotplt->contents + lit_offset); /* Fill in the entry in the procedure linkage table. */ memcpy (splt->contents + code_offset, (bfd_big_endian (output_bfd) ? elf_xtensa_be_plt_entry : elf_xtensa_le_plt_entry), PLT_ENTRY_SIZE); bfd_put_16 (output_bfd, l32r_offset (got_base + 0, plt_base + code_offset + 3), splt->contents + code_offset + 4); bfd_put_16 (output_bfd, l32r_offset (got_base + 4, plt_base + code_offset + 6), splt->contents + code_offset + 7); bfd_put_16 (output_bfd, l32r_offset (got_base + lit_offset, plt_base + code_offset + 9), splt->contents + code_offset + 10); return plt_base + code_offset; } static bfd_boolean get_indirect_call_dest_reg (xtensa_opcode, unsigned *); static bfd_boolean replace_tls_insn (Elf_Internal_Rela *rel, bfd *abfd, asection *input_section, bfd_byte *contents, bfd_boolean is_ld_model, char **error_message) { static xtensa_insnbuf ibuff = NULL; static xtensa_insnbuf sbuff = NULL; xtensa_isa isa = xtensa_default_isa; xtensa_format fmt; xtensa_opcode old_op, new_op; bfd_size_type input_size; int r_type; unsigned dest_reg, src_reg; if (ibuff == NULL) { ibuff = xtensa_insnbuf_alloc (isa); sbuff = xtensa_insnbuf_alloc (isa); } input_size = bfd_get_section_limit (abfd, input_section); /* Read the instruction into a buffer and decode the opcode. */ xtensa_insnbuf_from_chars (isa, ibuff, contents + rel->r_offset, input_size - rel->r_offset); fmt = xtensa_format_decode (isa, ibuff); if (fmt == XTENSA_UNDEFINED) { *error_message = "cannot decode instruction format"; return FALSE; } BFD_ASSERT (xtensa_format_num_slots (isa, fmt) == 1); xtensa_format_get_slot (isa, fmt, 0, ibuff, sbuff); old_op = xtensa_opcode_decode (isa, fmt, 0, sbuff); if (old_op == XTENSA_UNDEFINED) { *error_message = "cannot decode instruction opcode"; return FALSE; } r_type = ELF32_R_TYPE (rel->r_info); switch (r_type) { case R_XTENSA_TLS_FUNC: case R_XTENSA_TLS_ARG: if (old_op != get_l32r_opcode () || xtensa_operand_get_field (isa, old_op, 0, fmt, 0, sbuff, &dest_reg) != 0) { *error_message = "cannot extract L32R destination for TLS access"; return FALSE; } break; case R_XTENSA_TLS_CALL: if (! get_indirect_call_dest_reg (old_op, &dest_reg) || xtensa_operand_get_field (isa, old_op, 0, fmt, 0, sbuff, &src_reg) != 0) { *error_message = "cannot extract CALLXn operands for TLS access"; return FALSE; } break; default: abort (); } if (is_ld_model) { switch (r_type) { case R_XTENSA_TLS_FUNC: case R_XTENSA_TLS_ARG: /* Change the instruction to a NOP (or "OR a1, a1, a1" for older versions of Xtensa). */ new_op = xtensa_opcode_lookup (isa, "nop"); if (new_op == XTENSA_UNDEFINED) { new_op = xtensa_opcode_lookup (isa, "or"); if (new_op == XTENSA_UNDEFINED || xtensa_opcode_encode (isa, fmt, 0, sbuff, new_op) != 0 || xtensa_operand_set_field (isa, new_op, 0, fmt, 0, sbuff, 1) != 0 || xtensa_operand_set_field (isa, new_op, 1, fmt, 0, sbuff, 1) != 0 || xtensa_operand_set_field (isa, new_op, 2, fmt, 0, sbuff, 1) != 0) { *error_message = "cannot encode OR for TLS access"; return FALSE; } } else { if (xtensa_opcode_encode (isa, fmt, 0, sbuff, new_op) != 0) { *error_message = "cannot encode NOP for TLS access"; return FALSE; } } break; case R_XTENSA_TLS_CALL: /* Read THREADPTR into the CALLX's return value register. */ new_op = xtensa_opcode_lookup (isa, "rur.threadptr"); if (new_op == XTENSA_UNDEFINED || xtensa_opcode_encode (isa, fmt, 0, sbuff, new_op) != 0 || xtensa_operand_set_field (isa, new_op, 0, fmt, 0, sbuff, dest_reg + 2) != 0) { *error_message = "cannot encode RUR.THREADPTR for TLS access"; return FALSE; } break; } } else { switch (r_type) { case R_XTENSA_TLS_FUNC: new_op = xtensa_opcode_lookup (isa, "rur.threadptr"); if (new_op == XTENSA_UNDEFINED || xtensa_opcode_encode (isa, fmt, 0, sbuff, new_op) != 0 || xtensa_operand_set_field (isa, new_op, 0, fmt, 0, sbuff, dest_reg) != 0) { *error_message = "cannot encode RUR.THREADPTR for TLS access"; return FALSE; } break; case R_XTENSA_TLS_ARG: /* Nothing to do. Keep the original L32R instruction. */ return TRUE; case R_XTENSA_TLS_CALL: /* Add the CALLX's src register (holding the THREADPTR value) to the first argument register (holding the offset) and put the result in the CALLX's return value register. */ new_op = xtensa_opcode_lookup (isa, "add"); if (new_op == XTENSA_UNDEFINED || xtensa_opcode_encode (isa, fmt, 0, sbuff, new_op) != 0 || xtensa_operand_set_field (isa, new_op, 0, fmt, 0, sbuff, dest_reg + 2) != 0 || xtensa_operand_set_field (isa, new_op, 1, fmt, 0, sbuff, dest_reg + 2) != 0 || xtensa_operand_set_field (isa, new_op, 2, fmt, 0, sbuff, src_reg) != 0) { *error_message = "cannot encode ADD for TLS access"; return FALSE; } break; } } xtensa_format_set_slot (isa, fmt, 0, ibuff, sbuff); xtensa_insnbuf_to_chars (isa, ibuff, contents + rel->r_offset, input_size - rel->r_offset); return TRUE; } #define IS_XTENSA_TLS_RELOC(R_TYPE) \ ((R_TYPE) == R_XTENSA_TLSDESC_FN \ || (R_TYPE) == R_XTENSA_TLSDESC_ARG \ || (R_TYPE) == R_XTENSA_TLS_DTPOFF \ || (R_TYPE) == R_XTENSA_TLS_TPOFF \ || (R_TYPE) == R_XTENSA_TLS_FUNC \ || (R_TYPE) == R_XTENSA_TLS_ARG \ || (R_TYPE) == R_XTENSA_TLS_CALL) /* Relocate an Xtensa ELF section. This is invoked by the linker for both relocatable and final links. */ static bfd_boolean elf_xtensa_relocate_section (bfd *output_bfd, struct bfd_link_info *info, bfd *input_bfd, asection *input_section, bfd_byte *contents, Elf_Internal_Rela *relocs, Elf_Internal_Sym *local_syms, asection **local_sections) { struct elf_xtensa_link_hash_table *htab; Elf_Internal_Shdr *symtab_hdr; Elf_Internal_Rela *rel; Elf_Internal_Rela *relend; struct elf_link_hash_entry **sym_hashes; property_table_entry *lit_table = 0; int ltblsize = 0; char *local_got_tls_types; char *error_message = NULL; bfd_size_type input_size; int tls_type; if (!xtensa_default_isa) xtensa_default_isa = xtensa_isa_init (0, 0); BFD_ASSERT (is_xtensa_elf (input_bfd)); htab = elf_xtensa_hash_table (info); if (htab == NULL) return FALSE; symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr; sym_hashes = elf_sym_hashes (input_bfd); local_got_tls_types = elf_xtensa_local_got_tls_type (input_bfd); if (elf_hash_table (info)->dynamic_sections_created) { ltblsize = xtensa_read_table_entries (input_bfd, input_section, &lit_table, XTENSA_LIT_SEC_NAME, TRUE); if (ltblsize < 0) return FALSE; } input_size = bfd_get_section_limit (input_bfd, input_section); rel = relocs; relend = relocs + input_section->reloc_count; for (; rel < relend; rel++) { int r_type; reloc_howto_type *howto; unsigned long r_symndx; struct elf_link_hash_entry *h; Elf_Internal_Sym *sym; char sym_type; const char *name; asection *sec; bfd_vma relocation; bfd_reloc_status_type r; bfd_boolean is_weak_undef; bfd_boolean unresolved_reloc; bfd_boolean warned; bfd_boolean dynamic_symbol; r_type = ELF32_R_TYPE (rel->r_info); if (r_type == (int) R_XTENSA_GNU_VTINHERIT || r_type == (int) R_XTENSA_GNU_VTENTRY) continue; if (r_type < 0 || r_type >= (int) R_XTENSA_max) { bfd_set_error (bfd_error_bad_value); return FALSE; } howto = &elf_howto_table[r_type]; r_symndx = ELF32_R_SYM (rel->r_info); h = NULL; sym = NULL; sec = NULL; is_weak_undef = FALSE; unresolved_reloc = FALSE; warned = FALSE; if (howto->partial_inplace && !info->relocatable) { /* Because R_XTENSA_32 was made partial_inplace to fix some problems with DWARF info in partial links, there may be an addend stored in the contents. Take it out of there and move it back into the addend field of the reloc. */ rel->r_addend += bfd_get_32 (input_bfd, contents + rel->r_offset); bfd_put_32 (input_bfd, 0, contents + rel->r_offset); } if (r_symndx < symtab_hdr->sh_info) { sym = local_syms + r_symndx; sym_type = ELF32_ST_TYPE (sym->st_info); sec = local_sections[r_symndx]; relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel); } else { RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel, r_symndx, symtab_hdr, sym_hashes, h, sec, relocation, unresolved_reloc, warned); if (relocation == 0 && !unresolved_reloc && h->root.type == bfd_link_hash_undefweak) is_weak_undef = TRUE; sym_type = h->type; } if (sec != NULL && elf_discarded_section (sec)) RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section, rel, relend, howto, contents); if (info->relocatable) { bfd_vma dest_addr; asection * sym_sec = get_elf_r_symndx_section (input_bfd, r_symndx); /* This is a relocatable link. 1) If the reloc is against a section symbol, adjust according to the output section. 2) If there is a new target for this relocation, the new target will be in the same output section. We adjust the relocation by the output section difference. */ if (relaxing_section) { /* Check if this references a section in another input file. */ if (!do_fix_for_relocatable_link (rel, input_bfd, input_section, contents)) return FALSE; } dest_addr = sym_sec->output_section->vma + sym_sec->output_offset + get_elf_r_symndx_offset (input_bfd, r_symndx) + rel->r_addend; if (r_type == R_XTENSA_ASM_SIMPLIFY) { error_message = NULL; /* Convert ASM_SIMPLIFY into the simpler relocation so that they never escape a relaxing link. */ r = contract_asm_expansion (contents, input_size, rel, &error_message); if (r != bfd_reloc_ok) { if (!((*info->callbacks->reloc_dangerous) (info, error_message, input_bfd, input_section, rel->r_offset))) return FALSE; } r_type = ELF32_R_TYPE (rel->r_info); } /* This is a relocatable link, so we don't have to change anything unless the reloc is against a section symbol, in which case we have to adjust according to where the section symbol winds up in the output section. */ if (r_symndx < symtab_hdr->sh_info) { sym = local_syms + r_symndx; if (ELF_ST_TYPE (sym->st_info) == STT_SECTION) { sec = local_sections[r_symndx]; rel->r_addend += sec->output_offset + sym->st_value; } } /* If there is an addend with a partial_inplace howto, then move the addend to the contents. This is a hack to work around problems with DWARF in relocatable links with some previous version of BFD. Now we can't easily get rid of the hack without breaking backward compatibility.... */ r = bfd_reloc_ok; howto = &elf_howto_table[r_type]; if (howto->partial_inplace && rel->r_addend) { r = elf_xtensa_do_reloc (howto, input_bfd, input_section, rel->r_addend, contents, rel->r_offset, FALSE, &error_message); rel->r_addend = 0; } else { /* Put the correct bits in the target instruction, even though the relocation will still be present in the output file. This makes disassembly clearer, as well as allowing loadable kernel modules to work without needing relocations on anything other than calls and l32r's. */ /* If it is not in the same section, there is nothing we can do. */ if (r_type >= R_XTENSA_SLOT0_OP && r_type <= R_XTENSA_SLOT14_OP && sym_sec->output_section == input_section->output_section) { r = elf_xtensa_do_reloc (howto, input_bfd, input_section, dest_addr, contents, rel->r_offset, FALSE, &error_message); } } if (r != bfd_reloc_ok) { if (!((*info->callbacks->reloc_dangerous) (info, error_message, input_bfd, input_section, rel->r_offset))) return FALSE; } /* Done with work for relocatable link; continue with next reloc. */ continue; } /* This is a final link. */ if (relaxing_section) { /* Check if this references a section in another input file. */ do_fix_for_final_link (rel, input_bfd, input_section, contents, &relocation); } /* Sanity check the address. */ if (rel->r_offset >= input_size && ELF32_R_TYPE (rel->r_info) != R_XTENSA_NONE) { (*_bfd_error_handler) (_("%B(%A+0x%lx): relocation offset out of range (size=0x%x)"), input_bfd, input_section, rel->r_offset, input_size); bfd_set_error (bfd_error_bad_value); return FALSE; } if (h != NULL) name = h->root.root.string; else { name = (bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link, sym->st_name)); if (name == NULL || *name == '\0') name = bfd_section_name (input_bfd, sec); } if (r_symndx != STN_UNDEF && r_type != R_XTENSA_NONE && (h == NULL || h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak) && IS_XTENSA_TLS_RELOC (r_type) != (sym_type == STT_TLS)) { (*_bfd_error_handler) ((sym_type == STT_TLS ? _("%B(%A+0x%lx): %s used with TLS symbol %s") : _("%B(%A+0x%lx): %s used with non-TLS symbol %s")), input_bfd, input_section, (long) rel->r_offset, howto->name, name); } dynamic_symbol = elf_xtensa_dynamic_symbol_p (h, info); tls_type = GOT_UNKNOWN; if (h) tls_type = elf_xtensa_hash_entry (h)->tls_type; else if (local_got_tls_types) tls_type = local_got_tls_types [r_symndx]; switch (r_type) { case R_XTENSA_32: case R_XTENSA_PLT: if (elf_hash_table (info)->dynamic_sections_created && (input_section->flags & SEC_ALLOC) != 0 && (dynamic_symbol || info->shared)) { Elf_Internal_Rela outrel; bfd_byte *loc; asection *srel; if (dynamic_symbol && r_type == R_XTENSA_PLT) srel = htab->srelplt; else srel = htab->srelgot; BFD_ASSERT (srel != NULL); outrel.r_offset = _bfd_elf_section_offset (output_bfd, info, input_section, rel->r_offset); if ((outrel.r_offset | 1) == (bfd_vma) -1) memset (&outrel, 0, sizeof outrel); else { outrel.r_offset += (input_section->output_section->vma + input_section->output_offset); /* Complain if the relocation is in a read-only section and not in a literal pool. */ if ((input_section->flags & SEC_READONLY) != 0 && !elf_xtensa_in_literal_pool (lit_table, ltblsize, outrel.r_offset)) { error_message = _("dynamic relocation in read-only section"); if (!((*info->callbacks->reloc_dangerous) (info, error_message, input_bfd, input_section, rel->r_offset))) return FALSE; } if (dynamic_symbol) { outrel.r_addend = rel->r_addend; rel->r_addend = 0; if (r_type == R_XTENSA_32) { outrel.r_info = ELF32_R_INFO (h->dynindx, R_XTENSA_GLOB_DAT); relocation = 0; } else /* r_type == R_XTENSA_PLT */ { outrel.r_info = ELF32_R_INFO (h->dynindx, R_XTENSA_JMP_SLOT); /* Create the PLT entry and set the initial contents of the literal entry to the address of the PLT entry. */ relocation = elf_xtensa_create_plt_entry (info, output_bfd, srel->reloc_count); } unresolved_reloc = FALSE; } else { /* Generate a RELATIVE relocation. */ outrel.r_info = ELF32_R_INFO (0, R_XTENSA_RELATIVE); outrel.r_addend = 0; } } loc = (srel->contents + srel->reloc_count++ * sizeof (Elf32_External_Rela)); bfd_elf32_swap_reloca_out (output_bfd, &outrel, loc); BFD_ASSERT (sizeof (Elf32_External_Rela) * srel->reloc_count <= srel->size); } else if (r_type == R_XTENSA_ASM_EXPAND && dynamic_symbol) { /* This should only happen for non-PIC code, which is not supposed to be used on systems with dynamic linking. Just ignore these relocations. */ continue; } break; case R_XTENSA_TLS_TPOFF: /* Switch to LE model for local symbols in an executable. */ if (! info->shared && ! dynamic_symbol) { relocation = tpoff (info, relocation); break; } /* fall through */ case R_XTENSA_TLSDESC_FN: case R_XTENSA_TLSDESC_ARG: { if (r_type == R_XTENSA_TLSDESC_FN) { if (! info->shared || (tls_type & GOT_TLS_IE) != 0) r_type = R_XTENSA_NONE; } else if (r_type == R_XTENSA_TLSDESC_ARG) { if (info->shared) { if ((tls_type & GOT_TLS_IE) != 0) r_type = R_XTENSA_TLS_TPOFF; } else { r_type = R_XTENSA_TLS_TPOFF; if (! dynamic_symbol) { relocation = tpoff (info, relocation); break; } } } if (r_type == R_XTENSA_NONE) /* Nothing to do here; skip to the next reloc. */ continue; if (! elf_hash_table (info)->dynamic_sections_created) { error_message = _("TLS relocation invalid without dynamic sections"); if (!((*info->callbacks->reloc_dangerous) (info, error_message, input_bfd, input_section, rel->r_offset))) return FALSE; } else { Elf_Internal_Rela outrel; bfd_byte *loc; asection *srel = htab->srelgot; int indx; outrel.r_offset = (input_section->output_section->vma + input_section->output_offset + rel->r_offset); /* Complain if the relocation is in a read-only section and not in a literal pool. */ if ((input_section->flags & SEC_READONLY) != 0 && ! elf_xtensa_in_literal_pool (lit_table, ltblsize, outrel.r_offset)) { error_message = _("dynamic relocation in read-only section"); if (!((*info->callbacks->reloc_dangerous) (info, error_message, input_bfd, input_section, rel->r_offset))) return FALSE; } indx = h && h->dynindx != -1 ? h->dynindx : 0; if (indx == 0) outrel.r_addend = relocation - dtpoff_base (info); else outrel.r_addend = 0; rel->r_addend = 0; outrel.r_info = ELF32_R_INFO (indx, r_type); relocation = 0; unresolved_reloc = FALSE; BFD_ASSERT (srel); loc = (srel->contents + srel->reloc_count++ * sizeof (Elf32_External_Rela)); bfd_elf32_swap_reloca_out (output_bfd, &outrel, loc); BFD_ASSERT (sizeof (Elf32_External_Rela) * srel->reloc_count <= srel->size); } } break; case R_XTENSA_TLS_DTPOFF: if (! info->shared) /* Switch from LD model to LE model. */ relocation = tpoff (info, relocation); else relocation -= dtpoff_base (info); break; case R_XTENSA_TLS_FUNC: case R_XTENSA_TLS_ARG: case R_XTENSA_TLS_CALL: /* Check if optimizing to IE or LE model. */ if ((tls_type & GOT_TLS_IE) != 0) { bfd_boolean is_ld_model = (h && elf_xtensa_hash_entry (h) == htab->tlsbase); if (! replace_tls_insn (rel, input_bfd, input_section, contents, is_ld_model, &error_message)) { if (!((*info->callbacks->reloc_dangerous) (info, error_message, input_bfd, input_section, rel->r_offset))) return FALSE; } if (r_type != R_XTENSA_TLS_ARG || is_ld_model) { /* Skip subsequent relocations on the same instruction. */ while (rel + 1 < relend && rel[1].r_offset == rel->r_offset) rel++; } } continue; default: if (elf_hash_table (info)->dynamic_sections_created && dynamic_symbol && (is_operand_relocation (r_type) || r_type == R_XTENSA_32_PCREL)) { error_message = vsprint_msg ("invalid relocation for dynamic symbol", ": %s", strlen (name) + 2, name); if (!((*info->callbacks->reloc_dangerous) (info, error_message, input_bfd, input_section, rel->r_offset))) return FALSE; continue; } break; } /* Dynamic relocs are not propagated for SEC_DEBUGGING sections because such sections are not SEC_ALLOC and thus ld.so will not process them. */ if (unresolved_reloc && !((input_section->flags & SEC_DEBUGGING) != 0 && h->def_dynamic)) { (*_bfd_error_handler) (_("%B(%A+0x%lx): unresolvable %s relocation against symbol `%s'"), input_bfd, input_section, (long) rel->r_offset, howto->name, name); return FALSE; } /* TLS optimizations may have changed r_type; update "howto". */ howto = &elf_howto_table[r_type]; /* There's no point in calling bfd_perform_relocation here. Just go directly to our "special function". */ r = elf_xtensa_do_reloc (howto, input_bfd, input_section, relocation + rel->r_addend, contents, rel->r_offset, is_weak_undef, &error_message); if (r != bfd_reloc_ok && !warned) { BFD_ASSERT (r == bfd_reloc_dangerous || r == bfd_reloc_other); BFD_ASSERT (error_message != NULL); if (rel->r_addend == 0) error_message = vsprint_msg (error_message, ": %s", strlen (name) + 2, name); else error_message = vsprint_msg (error_message, ": (%s+0x%x)", strlen (name) + 22, name, (int) rel->r_addend); if (!((*info->callbacks->reloc_dangerous) (info, error_message, input_bfd, input_section, rel->r_offset))) return FALSE; } } if (lit_table) free (lit_table); input_section->reloc_done = TRUE; return TRUE; } /* Finish up dynamic symbol handling. There's not much to do here since the PLT and GOT entries are all set up by relocate_section. */ static bfd_boolean elf_xtensa_finish_dynamic_symbol (bfd *output_bfd ATTRIBUTE_UNUSED, struct bfd_link_info *info ATTRIBUTE_UNUSED, struct elf_link_hash_entry *h, Elf_Internal_Sym *sym) { if (h->needs_plt && !h->def_regular) { /* Mark the symbol as undefined, rather than as defined in the .plt section. Leave the value alone. */ sym->st_shndx = SHN_UNDEF; /* If the symbol is weak, we do need to clear the value. Otherwise, the PLT entry would provide a definition for the symbol even if the symbol wasn't defined anywhere, and so the symbol would never be NULL. */ if (!h->ref_regular_nonweak) sym->st_value = 0; } /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. */ if (strcmp (h->root.root.string, "_DYNAMIC") == 0 || h == elf_hash_table (info)->hgot) sym->st_shndx = SHN_ABS; return TRUE; } /* Combine adjacent literal table entries in the output. Adjacent entries within each input section may have been removed during relaxation, but we repeat the process here, even though it's too late to shrink the output section, because it's important to minimize the number of literal table entries to reduce the start-up work for the runtime linker. Returns the number of remaining table entries or -1 on error. */ static int elf_xtensa_combine_prop_entries (bfd *output_bfd, asection *sxtlit, asection *sgotloc) { bfd_byte *contents; property_table_entry *table; bfd_size_type section_size, sgotloc_size; bfd_vma offset; int n, m, num; section_size = sxtlit->size; BFD_ASSERT (section_size % 8 == 0); num = section_size / 8; sgotloc_size = sgotloc->size; if (sgotloc_size != section_size) { (*_bfd_error_handler) (_("internal inconsistency in size of .got.loc section")); return -1; } table = bfd_malloc (num * sizeof (property_table_entry)); if (table == 0) return -1; /* The ".xt.lit.plt" section has the SEC_IN_MEMORY flag set and this propagates to the output section, where it doesn't really apply and where it breaks the following call to bfd_malloc_and_get_section. */ sxtlit->flags &= ~SEC_IN_MEMORY; if (!bfd_malloc_and_get_section (output_bfd, sxtlit, &contents)) { if (contents != 0) free (contents); free (table); return -1; } /* There should never be any relocations left at this point, so this is quite a bit easier than what is done during relaxation. */ /* Copy the raw contents into a property table array and sort it. */ offset = 0; for (n = 0; n < num; n++) { table[n].address = bfd_get_32 (output_bfd, &contents[offset]); table[n].size = bfd_get_32 (output_bfd, &contents[offset + 4]); offset += 8; } qsort (table, num, sizeof (property_table_entry), property_table_compare); for (n = 0; n < num; n++) { bfd_boolean remove_entry = FALSE; if (table[n].size == 0) remove_entry = TRUE; else if (n > 0 && (table[n-1].address + table[n-1].size == table[n].address)) { table[n-1].size += table[n].size; remove_entry = TRUE; } if (remove_entry) { for (m = n; m < num - 1; m++) { table[m].address = table[m+1].address; table[m].size = table[m+1].size; } n--; num--; } } /* Copy the data back to the raw contents. */ offset = 0; for (n = 0; n < num; n++) { bfd_put_32 (output_bfd, table[n].address, &contents[offset]); bfd_put_32 (output_bfd, table[n].size, &contents[offset + 4]); offset += 8; } /* Clear the removed bytes. */ if ((bfd_size_type) (num * 8) < section_size) memset (&contents[num * 8], 0, section_size - num * 8); if (! bfd_set_section_contents (output_bfd, sxtlit, contents, 0, section_size)) return -1; /* Copy the contents to ".got.loc". */ memcpy (sgotloc->contents, contents, section_size); free (contents); free (table); return num; } /* Finish up the dynamic sections. */ static bfd_boolean elf_xtensa_finish_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info) { struct elf_xtensa_link_hash_table *htab; bfd *dynobj; asection *sdyn, *srelplt, *sgot, *sxtlit, *sgotloc; Elf32_External_Dyn *dyncon, *dynconend; int num_xtlit_entries = 0; if (! elf_hash_table (info)->dynamic_sections_created) return TRUE; htab = elf_xtensa_hash_table (info); if (htab == NULL) return FALSE; dynobj = elf_hash_table (info)->dynobj; sdyn = bfd_get_section_by_name (dynobj, ".dynamic"); BFD_ASSERT (sdyn != NULL); /* Set the first entry in the global offset table to the address of the dynamic section. */ sgot = htab->sgot; if (sgot) { BFD_ASSERT (sgot->size == 4); if (sdyn == NULL) bfd_put_32 (output_bfd, 0, sgot->contents); else bfd_put_32 (output_bfd, sdyn->output_section->vma + sdyn->output_offset, sgot->contents); } srelplt = htab->srelplt; if (srelplt && srelplt->size != 0) { asection *sgotplt, *srelgot, *spltlittbl; int chunk, plt_chunks, plt_entries; Elf_Internal_Rela irela; bfd_byte *loc; unsigned rtld_reloc; srelgot = htab->srelgot; spltlittbl = htab->spltlittbl; BFD_ASSERT (srelgot != NULL && spltlittbl != NULL); /* Find the first XTENSA_RTLD relocation. Presumably the rest of them follow immediately after.... */ for (rtld_reloc = 0; rtld_reloc < srelgot->reloc_count; rtld_reloc++) { loc = srelgot->contents + rtld_reloc * sizeof (Elf32_External_Rela); bfd_elf32_swap_reloca_in (output_bfd, loc, &irela); if (ELF32_R_TYPE (irela.r_info) == R_XTENSA_RTLD) break; } BFD_ASSERT (rtld_reloc < srelgot->reloc_count); plt_entries = srelplt->size / sizeof (Elf32_External_Rela); plt_chunks = (plt_entries + PLT_ENTRIES_PER_CHUNK - 1) / PLT_ENTRIES_PER_CHUNK; for (chunk = 0; chunk < plt_chunks; chunk++) { int chunk_entries = 0; sgotplt = elf_xtensa_get_gotplt_section (info, chunk); BFD_ASSERT (sgotplt != NULL); /* Emit special RTLD relocations for the first two entries in each chunk of the .got.plt section. */ loc = srelgot->contents + rtld_reloc * sizeof (Elf32_External_Rela); bfd_elf32_swap_reloca_in (output_bfd, loc, &irela); BFD_ASSERT (ELF32_R_TYPE (irela.r_info) == R_XTENSA_RTLD); irela.r_offset = (sgotplt->output_section->vma + sgotplt->output_offset); irela.r_addend = 1; /* tell rtld to set value to resolver function */ bfd_elf32_swap_reloca_out (output_bfd, &irela, loc); rtld_reloc += 1; BFD_ASSERT (rtld_reloc <= srelgot->reloc_count); /* Next literal immediately follows the first. */ loc += sizeof (Elf32_External_Rela); bfd_elf32_swap_reloca_in (output_bfd, loc, &irela); BFD_ASSERT (ELF32_R_TYPE (irela.r_info) == R_XTENSA_RTLD); irela.r_offset = (sgotplt->output_section->vma + sgotplt->output_offset + 4); /* Tell rtld to set value to object's link map. */ irela.r_addend = 2; bfd_elf32_swap_reloca_out (output_bfd, &irela, loc); rtld_reloc += 1; BFD_ASSERT (rtld_reloc <= srelgot->reloc_count); /* Fill in the literal table. */ if (chunk < plt_chunks - 1) chunk_entries = PLT_ENTRIES_PER_CHUNK; else chunk_entries = plt_entries - (chunk * PLT_ENTRIES_PER_CHUNK); BFD_ASSERT ((unsigned) (chunk + 1) * 8 <= spltlittbl->size); bfd_put_32 (output_bfd, sgotplt->output_section->vma + sgotplt->output_offset, spltlittbl->contents + (chunk * 8) + 0); bfd_put_32 (output_bfd, 8 + (chunk_entries * 4), spltlittbl->contents + (chunk * 8) + 4); } /* All the dynamic relocations have been emitted at this point. Make sure the relocation sections are the correct size. */ if (srelgot->size != (sizeof (Elf32_External_Rela) * srelgot->reloc_count) || srelplt->size != (sizeof (Elf32_External_Rela) * srelplt->reloc_count)) abort (); /* The .xt.lit.plt section has just been modified. This must happen before the code below which combines adjacent literal table entries, and the .xt.lit.plt contents have to be forced to the output here. */ if (! bfd_set_section_contents (output_bfd, spltlittbl->output_section, spltlittbl->contents, spltlittbl->output_offset, spltlittbl->size)) return FALSE; /* Clear SEC_HAS_CONTENTS so the contents won't be output again. */ spltlittbl->flags &= ~SEC_HAS_CONTENTS; } /* Combine adjacent literal table entries. */ BFD_ASSERT (! info->relocatable); sxtlit = bfd_get_section_by_name (output_bfd, ".xt.lit"); sgotloc = htab->sgotloc; BFD_ASSERT (sgotloc); if (sxtlit) { num_xtlit_entries = elf_xtensa_combine_prop_entries (output_bfd, sxtlit, sgotloc); if (num_xtlit_entries < 0) return FALSE; } dyncon = (Elf32_External_Dyn *) sdyn->contents; dynconend = (Elf32_External_Dyn *) (sdyn->contents + sdyn->size); for (; dyncon < dynconend; dyncon++) { Elf_Internal_Dyn dyn; bfd_elf32_swap_dyn_in (dynobj, dyncon, &dyn); switch (dyn.d_tag) { default: break; case DT_XTENSA_GOT_LOC_SZ: dyn.d_un.d_val = num_xtlit_entries; break; case DT_XTENSA_GOT_LOC_OFF: dyn.d_un.d_ptr = htab->sgotloc->output_section->vma; break; case DT_PLTGOT: dyn.d_un.d_ptr = htab->sgot->output_section->vma; break; case DT_JMPREL: dyn.d_un.d_ptr = htab->srelplt->output_section->vma; break; case DT_PLTRELSZ: dyn.d_un.d_val = htab->srelplt->output_section->size; break; case DT_RELASZ: /* Adjust RELASZ to not include JMPREL. This matches what glibc expects and what is done for several other ELF targets (e.g., i386, alpha), but the "correct" behavior seems to be unresolved. Since the linker script arranges for .rela.plt to follow all other relocation sections, we don't have to worry about changing the DT_RELA entry. */ if (htab->srelplt) dyn.d_un.d_val -= htab->srelplt->output_section->size; break; } bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon); } return TRUE; } /* Functions for dealing with the e_flags field. */ /* Merge backend specific data from an object file to the output object file when linking. */ static bfd_boolean elf_xtensa_merge_private_bfd_data (bfd *ibfd, bfd *obfd) { unsigned out_mach, in_mach; flagword out_flag, in_flag; /* Check if we have the same endianness. */ if (!_bfd_generic_verify_endian_match (ibfd, obfd)) return FALSE; /* Don't even pretend to support mixed-format linking. */ if (bfd_get_flavour (ibfd) != bfd_target_elf_flavour || bfd_get_flavour (obfd) != bfd_target_elf_flavour) return FALSE; out_flag = elf_elfheader (obfd)->e_flags; in_flag = elf_elfheader (ibfd)->e_flags; out_mach = out_flag & EF_XTENSA_MACH; in_mach = in_flag & EF_XTENSA_MACH; if (out_mach != in_mach) { (*_bfd_error_handler) (_("%B: incompatible machine type. Output is 0x%x. Input is 0x%x"), ibfd, out_mach, in_mach); bfd_set_error (bfd_error_wrong_format); return FALSE; } if (! elf_flags_init (obfd)) { elf_flags_init (obfd) = TRUE; elf_elfheader (obfd)->e_flags = in_flag; if (bfd_get_arch (obfd) == bfd_get_arch (ibfd) && bfd_get_arch_info (obfd)->the_default) return bfd_set_arch_mach (obfd, bfd_get_arch (ibfd), bfd_get_mach (ibfd)); return TRUE; } if ((out_flag & EF_XTENSA_XT_INSN) != (in_flag & EF_XTENSA_XT_INSN)) elf_elfheader (obfd)->e_flags &= (~ EF_XTENSA_XT_INSN); if ((out_flag & EF_XTENSA_XT_LIT) != (in_flag & EF_XTENSA_XT_LIT)) elf_elfheader (obfd)->e_flags &= (~ EF_XTENSA_XT_LIT); return TRUE; } static bfd_boolean elf_xtensa_set_private_flags (bfd *abfd, flagword flags) { BFD_ASSERT (!elf_flags_init (abfd) || elf_elfheader (abfd)->e_flags == flags); elf_elfheader (abfd)->e_flags |= flags; elf_flags_init (abfd) = TRUE; return TRUE; } static bfd_boolean elf_xtensa_print_private_bfd_data (bfd *abfd, void *farg) { FILE *f = (FILE *) farg; flagword e_flags = elf_elfheader (abfd)->e_flags; fprintf (f, "\nXtensa header:\n"); if ((e_flags & EF_XTENSA_MACH) == E_XTENSA_MACH) fprintf (f, "\nMachine = Base\n"); else fprintf (f, "\nMachine Id = 0x%x\n", e_flags & EF_XTENSA_MACH); fprintf (f, "Insn tables = %s\n", (e_flags & EF_XTENSA_XT_INSN) ? "true" : "false"); fprintf (f, "Literal tables = %s\n", (e_flags & EF_XTENSA_XT_LIT) ? "true" : "false"); return _bfd_elf_print_private_bfd_data (abfd, farg); } /* Set the right machine number for an Xtensa ELF file. */ static bfd_boolean elf_xtensa_object_p (bfd *abfd) { int mach; unsigned long arch = elf_elfheader (abfd)->e_flags & EF_XTENSA_MACH; switch (arch) { case E_XTENSA_MACH: mach = bfd_mach_xtensa; break; default: return FALSE; } (void) bfd_default_set_arch_mach (abfd, bfd_arch_xtensa, mach); return TRUE; } /* The final processing done just before writing out an Xtensa ELF object file. This gets the Xtensa architecture right based on the machine number. */ static void elf_xtensa_final_write_processing (bfd *abfd, bfd_boolean linker ATTRIBUTE_UNUSED) { int mach; unsigned long val; switch (mach = bfd_get_mach (abfd)) { case bfd_mach_xtensa: val = E_XTENSA_MACH; break; default: return; } elf_elfheader (abfd)->e_flags &= (~ EF_XTENSA_MACH); elf_elfheader (abfd)->e_flags |= val; } static enum elf_reloc_type_class elf_xtensa_reloc_type_class (const Elf_Internal_Rela *rela) { switch ((int) ELF32_R_TYPE (rela->r_info)) { case R_XTENSA_RELATIVE: return reloc_class_relative; case R_XTENSA_JMP_SLOT: return reloc_class_plt; default: return reloc_class_normal; } } static bfd_boolean elf_xtensa_discard_info_for_section (bfd *abfd, struct elf_reloc_cookie *cookie, struct bfd_link_info *info, asection *sec) { bfd_byte *contents; bfd_vma offset, actual_offset; bfd_size_type removed_bytes = 0; bfd_size_type entry_size; if (sec->output_section && bfd_is_abs_section (sec->output_section)) return FALSE; if (xtensa_is_proptable_section (sec)) entry_size = 12; else entry_size = 8; if (sec->size == 0 || sec->size % entry_size != 0) return FALSE; contents = retrieve_contents (abfd, sec, info->keep_memory); if (!contents) return FALSE; cookie->rels = retrieve_internal_relocs (abfd, sec, info->keep_memory); if (!cookie->rels) { release_contents (sec, contents); return FALSE; } /* Sort the relocations. They should already be in order when relaxation is enabled, but it might not be. */ qsort (cookie->rels, sec->reloc_count, sizeof (Elf_Internal_Rela), internal_reloc_compare); cookie->rel = cookie->rels; cookie->relend = cookie->rels + sec->reloc_count; for (offset = 0; offset < sec->size; offset += entry_size) { actual_offset = offset - removed_bytes; /* The ...symbol_deleted_p function will skip over relocs but it won't adjust their offsets, so do that here. */ while (cookie->rel < cookie->relend && cookie->rel->r_offset < offset) { cookie->rel->r_offset -= removed_bytes; cookie->rel++; } while (cookie->rel < cookie->relend && cookie->rel->r_offset == offset) { if (bfd_elf_reloc_symbol_deleted_p (offset, cookie)) { /* Remove the table entry. (If the reloc type is NONE, then the entry has already been merged with another and deleted during relaxation.) */ if (ELF32_R_TYPE (cookie->rel->r_info) != R_XTENSA_NONE) { /* Shift the contents up. */ if (offset + entry_size < sec->size) memmove (&contents[actual_offset], &contents[actual_offset + entry_size], sec->size - offset - entry_size); removed_bytes += entry_size; } /* Remove this relocation. */ cookie->rel->r_info = ELF32_R_INFO (0, R_XTENSA_NONE); } /* Adjust the relocation offset for previous removals. This should not be done before calling ...symbol_deleted_p because it might mess up the offset comparisons there. Make sure the offset doesn't underflow in the case where the first entry is removed. */ if (cookie->rel->r_offset >= removed_bytes) cookie->rel->r_offset -= removed_bytes; else cookie->rel->r_offset = 0; cookie->rel++; } } if (removed_bytes != 0) { /* Adjust any remaining relocs (shouldn't be any). */ for (; cookie->rel < cookie->relend; cookie->rel++) { if (cookie->rel->r_offset >= removed_bytes) cookie->rel->r_offset -= removed_bytes; else cookie->rel->r_offset = 0; } /* Clear the removed bytes. */ memset (&contents[sec->size - removed_bytes], 0, removed_bytes); pin_contents (sec, contents); pin_internal_relocs (sec, cookie->rels); /* Shrink size. */ if (sec->rawsize == 0) sec->rawsize = sec->size; sec->size -= removed_bytes; if (xtensa_is_littable_section (sec)) { asection *sgotloc = elf_xtensa_hash_table (info)->sgotloc; if (sgotloc) sgotloc->size -= removed_bytes; } } else { release_contents (sec, contents); release_internal_relocs (sec, cookie->rels); } return (removed_bytes != 0); } static bfd_boolean elf_xtensa_discard_info (bfd *abfd, struct elf_reloc_cookie *cookie, struct bfd_link_info *info) { asection *sec; bfd_boolean changed = FALSE; for (sec = abfd->sections; sec != NULL; sec = sec->next) { if (xtensa_is_property_section (sec)) { if (elf_xtensa_discard_info_for_section (abfd, cookie, info, sec)) changed = TRUE; } } return changed; } static bfd_boolean elf_xtensa_ignore_discarded_relocs (asection *sec) { return xtensa_is_property_section (sec); } static unsigned int elf_xtensa_action_discarded (asection *sec) { if (strcmp (".xt_except_table", sec->name) == 0) return 0; if (strcmp (".xt_except_desc", sec->name) == 0) return 0; return _bfd_elf_default_action_discarded (sec); } /* Support for core dump NOTE sections. */ static bfd_boolean elf_xtensa_grok_prstatus (bfd *abfd, Elf_Internal_Note *note) { int offset; unsigned int size; /* The size for Xtensa is variable, so don't try to recognize the format based on the size. Just assume this is GNU/Linux. */ /* pr_cursig */ elf_tdata (abfd)->core_signal = bfd_get_16 (abfd, note->descdata + 12); /* pr_pid */ elf_tdata (abfd)->core_lwpid = bfd_get_32 (abfd, note->descdata + 24); /* pr_reg */ offset = 72; size = note->descsz - offset - 4; /* Make a ".reg/999" section. */ return _bfd_elfcore_make_pseudosection (abfd, ".reg", size, note->descpos + offset); } static bfd_boolean elf_xtensa_grok_psinfo (bfd *abfd, Elf_Internal_Note *note) { switch (note->descsz) { default: return FALSE; case 128: /* GNU/Linux elf_prpsinfo */ elf_tdata (abfd)->core_program = _bfd_elfcore_strndup (abfd, note->descdata + 32, 16); elf_tdata (abfd)->core_command = _bfd_elfcore_strndup (abfd, note->descdata + 48, 80); } /* Note that for some reason, a spurious space is tacked onto the end of the args in some (at least one anyway) implementations, so strip it off if it exists. */ { char *command = elf_tdata (abfd)->core_command; int n = strlen (command); if (0 < n && command[n - 1] == ' ') command[n - 1] = '\0'; } return TRUE; } /* Generic Xtensa configurability stuff. */ static xtensa_opcode callx0_op = XTENSA_UNDEFINED; static xtensa_opcode callx4_op = XTENSA_UNDEFINED; static xtensa_opcode callx8_op = XTENSA_UNDEFINED; static xtensa_opcode callx12_op = XTENSA_UNDEFINED; static xtensa_opcode call0_op = XTENSA_UNDEFINED; static xtensa_opcode call4_op = XTENSA_UNDEFINED; static xtensa_opcode call8_op = XTENSA_UNDEFINED; static xtensa_opcode call12_op = XTENSA_UNDEFINED; static void init_call_opcodes (void) { if (callx0_op == XTENSA_UNDEFINED) { callx0_op = xtensa_opcode_lookup (xtensa_default_isa, "callx0"); callx4_op = xtensa_opcode_lookup (xtensa_default_isa, "callx4"); callx8_op = xtensa_opcode_lookup (xtensa_default_isa, "callx8"); callx12_op = xtensa_opcode_lookup (xtensa_default_isa, "callx12"); call0_op = xtensa_opcode_lookup (xtensa_default_isa, "call0"); call4_op = xtensa_opcode_lookup (xtensa_default_isa, "call4"); call8_op = xtensa_opcode_lookup (xtensa_default_isa, "call8"); call12_op = xtensa_opcode_lookup (xtensa_default_isa, "call12"); } } static bfd_boolean is_indirect_call_opcode (xtensa_opcode opcode) { init_call_opcodes (); return (opcode == callx0_op || opcode == callx4_op || opcode == callx8_op || opcode == callx12_op); } static bfd_boolean is_direct_call_opcode (xtensa_opcode opcode) { init_call_opcodes (); return (opcode == call0_op || opcode == call4_op || opcode == call8_op || opcode == call12_op); } static bfd_boolean is_windowed_call_opcode (xtensa_opcode opcode) { init_call_opcodes (); return (opcode == call4_op || opcode == call8_op || opcode == call12_op || opcode == callx4_op || opcode == callx8_op || opcode == callx12_op); } static bfd_boolean get_indirect_call_dest_reg (xtensa_opcode opcode, unsigned *pdst) { unsigned dst = (unsigned) -1; init_call_opcodes (); if (opcode == callx0_op) dst = 0; else if (opcode == callx4_op) dst = 4; else if (opcode == callx8_op) dst = 8; else if (opcode == callx12_op) dst = 12; if (dst == (unsigned) -1) return FALSE; *pdst = dst; return TRUE; } static xtensa_opcode get_const16_opcode (void) { static bfd_boolean done_lookup = FALSE; static xtensa_opcode const16_opcode = XTENSA_UNDEFINED; if (!done_lookup) { const16_opcode = xtensa_opcode_lookup (xtensa_default_isa, "const16"); done_lookup = TRUE; } return const16_opcode; } static xtensa_opcode get_l32r_opcode (void) { static xtensa_opcode l32r_opcode = XTENSA_UNDEFINED; static bfd_boolean done_lookup = FALSE; if (!done_lookup) { l32r_opcode = xtensa_opcode_lookup (xtensa_default_isa, "l32r"); done_lookup = TRUE; } return l32r_opcode; } static bfd_vma l32r_offset (bfd_vma addr, bfd_vma pc) { bfd_vma offset; offset = addr - ((pc+3) & -4); BFD_ASSERT ((offset & ((1 << 2) - 1)) == 0); offset = (signed int) offset >> 2; BFD_ASSERT ((signed int) offset >> 16 == -1); return offset; } static int get_relocation_opnd (xtensa_opcode opcode, int r_type) { xtensa_isa isa = xtensa_default_isa; int last_immed, last_opnd, opi; if (opcode == XTENSA_UNDEFINED) return XTENSA_UNDEFINED; /* Find the last visible PC-relative immediate operand for the opcode. If there are no PC-relative immediates, then choose the last visible immediate; otherwise, fail and return XTENSA_UNDEFINED. */ last_immed = XTENSA_UNDEFINED; last_opnd = xtensa_opcode_num_operands (isa, opcode); for (opi = last_opnd - 1; opi >= 0; opi--) { if (xtensa_operand_is_visible (isa, opcode, opi) == 0) continue; if (xtensa_operand_is_PCrelative (isa, opcode, opi) == 1) { last_immed = opi; break; } if (last_immed == XTENSA_UNDEFINED && xtensa_operand_is_register (isa, opcode, opi) == 0) last_immed = opi; } if (last_immed < 0) return XTENSA_UNDEFINED; /* If the operand number was specified in an old-style relocation, check for consistency with the operand computed above. */ if (r_type >= R_XTENSA_OP0 && r_type <= R_XTENSA_OP2) { int reloc_opnd = r_type - R_XTENSA_OP0; if (reloc_opnd != last_immed) return XTENSA_UNDEFINED; } return last_immed; } int get_relocation_slot (int r_type) { switch (r_type) { case R_XTENSA_OP0: case R_XTENSA_OP1: case R_XTENSA_OP2: return 0; default: if (r_type >= R_XTENSA_SLOT0_OP && r_type <= R_XTENSA_SLOT14_OP) return r_type - R_XTENSA_SLOT0_OP; if (r_type >= R_XTENSA_SLOT0_ALT && r_type <= R_XTENSA_SLOT14_ALT) return r_type - R_XTENSA_SLOT0_ALT; break; } return XTENSA_UNDEFINED; } /* Get the opcode for a relocation. */ static xtensa_opcode get_relocation_opcode (bfd *abfd, asection *sec, bfd_byte *contents, Elf_Internal_Rela *irel) { static xtensa_insnbuf ibuff = NULL; static xtensa_insnbuf sbuff = NULL; xtensa_isa isa = xtensa_default_isa; xtensa_format fmt; int slot; if (contents == NULL) return XTENSA_UNDEFINED; if (bfd_get_section_limit (abfd, sec) <= irel->r_offset) return XTENSA_UNDEFINED; if (ibuff == NULL) { ibuff = xtensa_insnbuf_alloc (isa); sbuff = xtensa_insnbuf_alloc (isa); } /* Decode the instruction. */ xtensa_insnbuf_from_chars (isa, ibuff, &contents[irel->r_offset], sec->size - irel->r_offset); fmt = xtensa_format_decode (isa, ibuff); slot = get_relocation_slot (ELF32_R_TYPE (irel->r_info)); if (slot == XTENSA_UNDEFINED) return XTENSA_UNDEFINED; xtensa_format_get_slot (isa, fmt, slot, ibuff, sbuff); return xtensa_opcode_decode (isa, fmt, slot, sbuff); } bfd_boolean is_l32r_relocation (bfd *abfd, asection *sec, bfd_byte *contents, Elf_Internal_Rela *irel) { xtensa_opcode opcode; if (!is_operand_relocation (ELF32_R_TYPE (irel->r_info))) return FALSE; opcode = get_relocation_opcode (abfd, sec, contents, irel); return (opcode == get_l32r_opcode ()); } static bfd_size_type get_asm_simplify_size (bfd_byte *contents, bfd_size_type content_len, bfd_size_type offset) { bfd_size_type insnlen, size = 0; /* Decode the size of the next two instructions. */ insnlen = insn_decode_len (contents, content_len, offset); if (insnlen == 0) return 0; size += insnlen; insnlen = insn_decode_len (contents, content_len, offset + size); if (insnlen == 0) return 0; size += insnlen; return size; } bfd_boolean is_alt_relocation (int r_type) { return (r_type >= R_XTENSA_SLOT0_ALT && r_type <= R_XTENSA_SLOT14_ALT); } bfd_boolean is_operand_relocation (int r_type) { switch (r_type) { case R_XTENSA_OP0: case R_XTENSA_OP1: case R_XTENSA_OP2: return TRUE; default: if (r_type >= R_XTENSA_SLOT0_OP && r_type <= R_XTENSA_SLOT14_OP) return TRUE; if (r_type >= R_XTENSA_SLOT0_ALT && r_type <= R_XTENSA_SLOT14_ALT) return TRUE; break; } return FALSE; } #define MIN_INSN_LENGTH 2 /* Return 0 if it fails to decode. */ bfd_size_type insn_decode_len (bfd_byte *contents, bfd_size_type content_len, bfd_size_type offset) { int insn_len; xtensa_isa isa = xtensa_default_isa; xtensa_format fmt; static xtensa_insnbuf ibuff = NULL; if (offset + MIN_INSN_LENGTH > content_len) return 0; if (ibuff == NULL) ibuff = xtensa_insnbuf_alloc (isa); xtensa_insnbuf_from_chars (isa, ibuff, &contents[offset], content_len - offset); fmt = xtensa_format_decode (isa, ibuff); if (fmt == XTENSA_UNDEFINED) return 0; insn_len = xtensa_format_length (isa, fmt); if (insn_len == XTENSA_UNDEFINED) return 0; return insn_len; } /* Decode the opcode for a single slot instruction. Return 0 if it fails to decode or the instruction is multi-slot. */ xtensa_opcode insn_decode_opcode (bfd_byte *contents, bfd_size_type content_len, bfd_size_type offset, int slot) { xtensa_isa isa = xtensa_default_isa; xtensa_format fmt; static xtensa_insnbuf insnbuf = NULL; static xtensa_insnbuf slotbuf = NULL; if (offset + MIN_INSN_LENGTH > content_len) return XTENSA_UNDEFINED; if (insnbuf == NULL) { insnbuf = xtensa_insnbuf_alloc (isa); slotbuf = xtensa_insnbuf_alloc (isa); } xtensa_insnbuf_from_chars (isa, insnbuf, &contents[offset], content_len - offset); fmt = xtensa_format_decode (isa, insnbuf); if (fmt == XTENSA_UNDEFINED) return XTENSA_UNDEFINED; if (slot >= xtensa_format_num_slots (isa, fmt)) return XTENSA_UNDEFINED; xtensa_format_get_slot (isa, fmt, slot, insnbuf, slotbuf); return xtensa_opcode_decode (isa, fmt, slot, slotbuf); } /* The offset is the offset in the contents. The address is the address of that offset. */ static bfd_boolean check_branch_target_aligned (bfd_byte *contents, bfd_size_type content_length, bfd_vma offset, bfd_vma address) { bfd_size_type insn_len = insn_decode_len (contents, content_length, offset); if (insn_len == 0) return FALSE; return check_branch_target_aligned_address (address, insn_len); } static bfd_boolean check_loop_aligned (bfd_byte *contents, bfd_size_type content_length, bfd_vma offset, bfd_vma address) { bfd_size_type loop_len, insn_len; xtensa_opcode opcode; opcode = insn_decode_opcode (contents, content_length, offset, 0); if (opcode == XTENSA_UNDEFINED || xtensa_opcode_is_loop (xtensa_default_isa, opcode) != 1) { BFD_ASSERT (FALSE); return FALSE; } loop_len = insn_decode_len (contents, content_length, offset); insn_len = insn_decode_len (contents, content_length, offset + loop_len); if (loop_len == 0 || insn_len == 0) { BFD_ASSERT (FALSE); return FALSE; } return check_branch_target_aligned_address (address + loop_len, insn_len); } static bfd_boolean check_branch_target_aligned_address (bfd_vma addr, int len) { if (len == 8) return (addr % 8 == 0); return ((addr >> 2) == ((addr + len - 1) >> 2)); } /* Instruction widening and narrowing. */ /* When FLIX is available we need to access certain instructions only when they are 16-bit or 24-bit instructions. This table caches information about such instructions by walking through all the opcodes and finding the smallest single-slot format into which each can be encoded. */ static xtensa_format *op_single_fmt_table = NULL; static void init_op_single_format_table (void) { xtensa_isa isa = xtensa_default_isa; xtensa_insnbuf ibuf; xtensa_opcode opcode; xtensa_format fmt; int num_opcodes; if (op_single_fmt_table) return; ibuf = xtensa_insnbuf_alloc (isa); num_opcodes = xtensa_isa_num_opcodes (isa); op_single_fmt_table = (xtensa_format *) bfd_malloc (sizeof (xtensa_format) * num_opcodes); for (opcode = 0; opcode < num_opcodes; opcode++) { op_single_fmt_table[opcode] = XTENSA_UNDEFINED; for (fmt = 0; fmt < xtensa_isa_num_formats (isa); fmt++) { if (xtensa_format_num_slots (isa, fmt) == 1 && xtensa_opcode_encode (isa, fmt, 0, ibuf, opcode) == 0) { xtensa_opcode old_fmt = op_single_fmt_table[opcode]; int fmt_length = xtensa_format_length (isa, fmt); if (old_fmt == XTENSA_UNDEFINED || fmt_length < xtensa_format_length (isa, old_fmt)) op_single_fmt_table[opcode] = fmt; } } } xtensa_insnbuf_free (isa, ibuf); } static xtensa_format get_single_format (xtensa_opcode opcode) { init_op_single_format_table (); return op_single_fmt_table[opcode]; } /* For the set of narrowable instructions we do NOT include the narrowings beqz -> beqz.n or bnez -> bnez.n because of complexities involved during linker relaxation that may require these to re-expand in some conditions. Also, the narrowing "or" -> mov.n requires special case code to ensure it only works when op1 == op2. */ struct string_pair { const char *wide; const char *narrow; }; struct string_pair narrowable[] = { { "add", "add.n" }, { "addi", "addi.n" }, { "addmi", "addi.n" }, { "l32i", "l32i.n" }, { "movi", "movi.n" }, { "ret", "ret.n" }, { "retw", "retw.n" }, { "s32i", "s32i.n" }, { "or", "mov.n" } /* special case only when op1 == op2 */ }; struct string_pair widenable[] = { { "add", "add.n" }, { "addi", "addi.n" }, { "addmi", "addi.n" }, { "beqz", "beqz.n" }, { "bnez", "bnez.n" }, { "l32i", "l32i.n" }, { "movi", "movi.n" }, { "ret", "ret.n" }, { "retw", "retw.n" }, { "s32i", "s32i.n" }, { "or", "mov.n" } /* special case only when op1 == op2 */ }; /* Check if an instruction can be "narrowed", i.e., changed from a standard 3-byte instruction to a 2-byte "density" instruction. If it is valid, return the instruction buffer holding the narrow instruction. Otherwise, return 0. The set of valid narrowing are specified by a string table but require some special case operand checks in some cases. */ static xtensa_insnbuf can_narrow_instruction (xtensa_insnbuf slotbuf, xtensa_format fmt, xtensa_opcode opcode) { xtensa_isa isa = xtensa_default_isa; xtensa_format o_fmt; unsigned opi; static xtensa_insnbuf o_insnbuf = NULL; static xtensa_insnbuf o_slotbuf = NULL; if (o_insnbuf == NULL) { o_insnbuf = xtensa_insnbuf_alloc (isa); o_slotbuf = xtensa_insnbuf_alloc (isa); } for (opi = 0; opi < (sizeof (narrowable)/sizeof (struct string_pair)); opi++) { bfd_boolean is_or = (strcmp ("or", narrowable[opi].wide) == 0); if (opcode == xtensa_opcode_lookup (isa, narrowable[opi].wide)) { uint32 value, newval; int i, operand_count, o_operand_count; xtensa_opcode o_opcode; /* Address does not matter in this case. We might need to fix it to handle branches/jumps. */ bfd_vma self_address = 0; o_opcode = xtensa_opcode_lookup (isa, narrowable[opi].narrow); if (o_opcode == XTENSA_UNDEFINED) return 0; o_fmt = get_single_format (o_opcode); if (o_fmt == XTENSA_UNDEFINED) return 0; if (xtensa_format_length (isa, fmt) != 3 || xtensa_format_length (isa, o_fmt) != 2) return 0; xtensa_format_encode (isa, o_fmt, o_insnbuf); operand_count = xtensa_opcode_num_operands (isa, opcode); o_operand_count = xtensa_opcode_num_operands (isa, o_opcode); if (xtensa_opcode_encode (isa, o_fmt, 0, o_slotbuf, o_opcode) != 0) return 0; if (!is_or) { if (xtensa_opcode_num_operands (isa, o_opcode) != operand_count) return 0; } else { uint32 rawval0, rawval1, rawval2; if (o_operand_count + 1 != operand_count || xtensa_operand_get_field (isa, opcode, 0, fmt, 0, slotbuf, &rawval0) != 0 || xtensa_operand_get_field (isa, opcode, 1, fmt, 0, slotbuf, &rawval1) != 0 || xtensa_operand_get_field (isa, opcode, 2, fmt, 0, slotbuf, &rawval2) != 0 || rawval1 != rawval2 || rawval0 == rawval1 /* it is a nop */) return 0; } for (i = 0; i < o_operand_count; ++i) { if (xtensa_operand_get_field (isa, opcode, i, fmt, 0, slotbuf, &value) || xtensa_operand_decode (isa, opcode, i, &value)) return 0; /* PC-relative branches need adjustment, but the PC-rel operand will always have a relocation. */ newval = value; if (xtensa_operand_do_reloc (isa, o_opcode, i, &newval, self_address) || xtensa_operand_encode (isa, o_opcode, i, &newval) || xtensa_operand_set_field (isa, o_opcode, i, o_fmt, 0, o_slotbuf, newval)) return 0; } if (xtensa_format_set_slot (isa, o_fmt, 0, o_insnbuf, o_slotbuf)) return 0; return o_insnbuf; } } return 0; } /* Attempt to narrow an instruction. If the narrowing is valid, perform the action in-place directly into the contents and return TRUE. Otherwise, the return value is FALSE and the contents are not modified. */ static bfd_boolean narrow_instruction (bfd_byte *contents, bfd_size_type content_length, bfd_size_type offset) { xtensa_opcode opcode; bfd_size_type insn_len; xtensa_isa isa = xtensa_default_isa; xtensa_format fmt; xtensa_insnbuf o_insnbuf; static xtensa_insnbuf insnbuf = NULL; static xtensa_insnbuf slotbuf = NULL; if (insnbuf == NULL) { insnbuf = xtensa_insnbuf_alloc (isa); slotbuf = xtensa_insnbuf_alloc (isa); } BFD_ASSERT (offset < content_length); if (content_length < 2) return FALSE; /* We will hand-code a few of these for a little while. These have all been specified in the assembler aleady. */ xtensa_insnbuf_from_chars (isa, insnbuf, &contents[offset], content_length - offset); fmt = xtensa_format_decode (isa, insnbuf); if (xtensa_format_num_slots (isa, fmt) != 1) return FALSE; if (xtensa_format_get_slot (isa, fmt, 0, insnbuf, slotbuf) != 0) return FALSE; opcode = xtensa_opcode_decode (isa, fmt, 0, slotbuf); if (opcode == XTENSA_UNDEFINED) return FALSE; insn_len = xtensa_format_length (isa, fmt); if (insn_len > content_length) return FALSE; o_insnbuf = can_narrow_instruction (slotbuf, fmt, opcode); if (o_insnbuf) { xtensa_insnbuf_to_chars (isa, o_insnbuf, contents + offset, content_length - offset); return TRUE; } return FALSE; } /* Check if an instruction can be "widened", i.e., changed from a 2-byte "density" instruction to a standard 3-byte instruction. If it is valid, return the instruction buffer holding the wide instruction. Otherwise, return 0. The set of valid widenings are specified by a string table but require some special case operand checks in some cases. */ static xtensa_insnbuf can_widen_instruction (xtensa_insnbuf slotbuf, xtensa_format fmt, xtensa_opcode opcode) { xtensa_isa isa = xtensa_default_isa; xtensa_format o_fmt; unsigned opi; static xtensa_insnbuf o_insnbuf = NULL; static xtensa_insnbuf o_slotbuf = NULL; if (o_insnbuf == NULL) { o_insnbuf = xtensa_insnbuf_alloc (isa); o_slotbuf = xtensa_insnbuf_alloc (isa); } for (opi = 0; opi < (sizeof (widenable)/sizeof (struct string_pair)); opi++) { bfd_boolean is_or = (strcmp ("or", widenable[opi].wide) == 0); bfd_boolean is_branch = (strcmp ("beqz", widenable[opi].wide) == 0 || strcmp ("bnez", widenable[opi].wide) == 0); if (opcode == xtensa_opcode_lookup (isa, widenable[opi].narrow)) { uint32 value, newval; int i, operand_count, o_operand_count, check_operand_count; xtensa_opcode o_opcode; /* Address does not matter in this case. We might need to fix it to handle branches/jumps. */ bfd_vma self_address = 0; o_opcode = xtensa_opcode_lookup (isa, widenable[opi].wide); if (o_opcode == XTENSA_UNDEFINED) return 0; o_fmt = get_single_format (o_opcode); if (o_fmt == XTENSA_UNDEFINED) return 0; if (xtensa_format_length (isa, fmt) != 2 || xtensa_format_length (isa, o_fmt) != 3) return 0; xtensa_format_encode (isa, o_fmt, o_insnbuf); operand_count = xtensa_opcode_num_operands (isa, opcode); o_operand_count = xtensa_opcode_num_operands (isa, o_opcode); check_operand_count = o_operand_count; if (xtensa_opcode_encode (isa, o_fmt, 0, o_slotbuf, o_opcode) != 0) return 0; if (!is_or) { if (xtensa_opcode_num_operands (isa, o_opcode) != operand_count) return 0; } else { uint32 rawval0, rawval1; if (o_operand_count != operand_count + 1 || xtensa_operand_get_field (isa, opcode, 0, fmt, 0, slotbuf, &rawval0) != 0 || xtensa_operand_get_field (isa, opcode, 1, fmt, 0, slotbuf, &rawval1) != 0 || rawval0 == rawval1 /* it is a nop */) return 0; } if (is_branch) check_operand_count--; for (i = 0; i < check_operand_count; i++) { int new_i = i; if (is_or && i == o_operand_count - 1) new_i = i - 1; if (xtensa_operand_get_field (isa, opcode, new_i, fmt, 0, slotbuf, &value) || xtensa_operand_decode (isa, opcode, new_i, &value)) return 0; /* PC-relative branches need adjustment, but the PC-rel operand will always have a relocation. */ newval = value; if (xtensa_operand_do_reloc (isa, o_opcode, i, &newval, self_address) || xtensa_operand_encode (isa, o_opcode, i, &newval) || xtensa_operand_set_field (isa, o_opcode, i, o_fmt, 0, o_slotbuf, newval)) return 0; } if (xtensa_format_set_slot (isa, o_fmt, 0, o_insnbuf, o_slotbuf)) return 0; return o_insnbuf; } } return 0; } /* Attempt to widen an instruction. If the widening is valid, perform the action in-place directly into the contents and return TRUE. Otherwise, the return value is FALSE and the contents are not modified. */ static bfd_boolean widen_instruction (bfd_byte *contents, bfd_size_type content_length, bfd_size_type offset) { xtensa_opcode opcode; bfd_size_type insn_len; xtensa_isa isa = xtensa_default_isa; xtensa_format fmt; xtensa_insnbuf o_insnbuf; static xtensa_insnbuf insnbuf = NULL; static xtensa_insnbuf slotbuf = NULL; if (insnbuf == NULL) { insnbuf = xtensa_insnbuf_alloc (isa); slotbuf = xtensa_insnbuf_alloc (isa); } BFD_ASSERT (offset < content_length); if (content_length < 2) return FALSE; /* We will hand-code a few of these for a little while. These have all been specified in the assembler aleady. */ xtensa_insnbuf_from_chars (isa, insnbuf, &contents[offset], content_length - offset); fmt = xtensa_format_decode (isa, insnbuf); if (xtensa_format_num_slots (isa, fmt) != 1) return FALSE; if (xtensa_format_get_slot (isa, fmt, 0, insnbuf, slotbuf) != 0) return FALSE; opcode = xtensa_opcode_decode (isa, fmt, 0, slotbuf); if (opcode == XTENSA_UNDEFINED) return FALSE; insn_len = xtensa_format_length (isa, fmt); if (insn_len > content_length) return FALSE; o_insnbuf = can_widen_instruction (slotbuf, fmt, opcode); if (o_insnbuf) { xtensa_insnbuf_to_chars (isa, o_insnbuf, contents + offset, content_length - offset); return TRUE; } return FALSE; } /* Code for transforming CALLs at link-time. */ static bfd_reloc_status_type elf_xtensa_do_asm_simplify (bfd_byte *contents, bfd_vma address, bfd_vma content_length, char **error_message) { static xtensa_insnbuf insnbuf = NULL; static xtensa_insnbuf slotbuf = NULL; xtensa_format core_format = XTENSA_UNDEFINED; xtensa_opcode opcode; xtensa_opcode direct_call_opcode; xtensa_isa isa = xtensa_default_isa; bfd_byte *chbuf = contents + address; int opn; if (insnbuf == NULL) { insnbuf = xtensa_insnbuf_alloc (isa); slotbuf = xtensa_insnbuf_alloc (isa); } if (content_length < address) { *error_message = _("Attempt to convert L32R/CALLX to CALL failed"); return bfd_reloc_other; } opcode = get_expanded_call_opcode (chbuf, content_length - address, 0); direct_call_opcode = swap_callx_for_call_opcode (opcode); if (direct_call_opcode == XTENSA_UNDEFINED) { *error_message = _("Attempt to convert L32R/CALLX to CALL failed"); return bfd_reloc_other; } /* Assemble a NOP ("or a1, a1, a1") into the 0 byte offset. */ core_format = xtensa_format_lookup (isa, "x24"); opcode = xtensa_opcode_lookup (isa, "or"); xtensa_opcode_encode (isa, core_format, 0, slotbuf, opcode); for (opn = 0; opn < 3; opn++) { uint32 regno = 1; xtensa_operand_encode (isa, opcode, opn, ®no); xtensa_operand_set_field (isa, opcode, opn, core_format, 0, slotbuf, regno); } xtensa_format_encode (isa, core_format, insnbuf); xtensa_format_set_slot (isa, core_format, 0, insnbuf, slotbuf); xtensa_insnbuf_to_chars (isa, insnbuf, chbuf, content_length - address); /* Assemble a CALL ("callN 0") into the 3 byte offset. */ xtensa_opcode_encode (isa, core_format, 0, slotbuf, direct_call_opcode); xtensa_operand_set_field (isa, opcode, 0, core_format, 0, slotbuf, 0); xtensa_format_encode (isa, core_format, insnbuf); xtensa_format_set_slot (isa, core_format, 0, insnbuf, slotbuf); xtensa_insnbuf_to_chars (isa, insnbuf, chbuf + 3, content_length - address - 3); return bfd_reloc_ok; } static bfd_reloc_status_type contract_asm_expansion (bfd_byte *contents, bfd_vma content_length, Elf_Internal_Rela *irel, char **error_message) { bfd_reloc_status_type retval = elf_xtensa_do_asm_simplify (contents, irel->r_offset, content_length, error_message); if (retval != bfd_reloc_ok) return bfd_reloc_dangerous; /* Update the irel->r_offset field so that the right immediate and the right instruction are modified during the relocation. */ irel->r_offset += 3; irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info), R_XTENSA_SLOT0_OP); return bfd_reloc_ok; } static xtensa_opcode swap_callx_for_call_opcode (xtensa_opcode opcode) { init_call_opcodes (); if (opcode == callx0_op) return call0_op; if (opcode == callx4_op) return call4_op; if (opcode == callx8_op) return call8_op; if (opcode == callx12_op) return call12_op; /* Return XTENSA_UNDEFINED if the opcode is not an indirect call. */ return XTENSA_UNDEFINED; } /* Check if "buf" is pointing to a "L32R aN; CALLX aN" or "CONST16 aN; CONST16 aN; CALLX aN" sequence, and if so, return the CALLX opcode. If not, return XTENSA_UNDEFINED. */ #define L32R_TARGET_REG_OPERAND 0 #define CONST16_TARGET_REG_OPERAND 0 #define CALLN_SOURCE_OPERAND 0 static xtensa_opcode get_expanded_call_opcode (bfd_byte *buf, int bufsize, bfd_boolean *p_uses_l32r) { static xtensa_insnbuf insnbuf = NULL; static xtensa_insnbuf slotbuf = NULL; xtensa_format fmt; xtensa_opcode opcode; xtensa_isa isa = xtensa_default_isa; uint32 regno, const16_regno, call_regno; int offset = 0; if (insnbuf == NULL) { insnbuf = xtensa_insnbuf_alloc (isa); slotbuf = xtensa_insnbuf_alloc (isa); } xtensa_insnbuf_from_chars (isa, insnbuf, buf, bufsize); fmt = xtensa_format_decode (isa, insnbuf); if (fmt == XTENSA_UNDEFINED || xtensa_format_get_slot (isa, fmt, 0, insnbuf, slotbuf)) return XTENSA_UNDEFINED; opcode = xtensa_opcode_decode (isa, fmt, 0, slotbuf); if (opcode == XTENSA_UNDEFINED) return XTENSA_UNDEFINED; if (opcode == get_l32r_opcode ()) { if (p_uses_l32r) *p_uses_l32r = TRUE; if (xtensa_operand_get_field (isa, opcode, L32R_TARGET_REG_OPERAND, fmt, 0, slotbuf, ®no) || xtensa_operand_decode (isa, opcode, L32R_TARGET_REG_OPERAND, ®no)) return XTENSA_UNDEFINED; } else if (opcode == get_const16_opcode ()) { if (p_uses_l32r) *p_uses_l32r = FALSE; if (xtensa_operand_get_field (isa, opcode, CONST16_TARGET_REG_OPERAND, fmt, 0, slotbuf, ®no) || xtensa_operand_decode (isa, opcode, CONST16_TARGET_REG_OPERAND, ®no)) return XTENSA_UNDEFINED; /* Check that the next instruction is also CONST16. */ offset += xtensa_format_length (isa, fmt); xtensa_insnbuf_from_chars (isa, insnbuf, buf + offset, bufsize - offset); fmt = xtensa_format_decode (isa, insnbuf); if (fmt == XTENSA_UNDEFINED || xtensa_format_get_slot (isa, fmt, 0, insnbuf, slotbuf)) return XTENSA_UNDEFINED; opcode = xtensa_opcode_decode (isa, fmt, 0, slotbuf); if (opcode != get_const16_opcode ()) return XTENSA_UNDEFINED; if (xtensa_operand_get_field (isa, opcode, CONST16_TARGET_REG_OPERAND, fmt, 0, slotbuf, &const16_regno) || xtensa_operand_decode (isa, opcode, CONST16_TARGET_REG_OPERAND, &const16_regno) || const16_regno != regno) return XTENSA_UNDEFINED; } else return XTENSA_UNDEFINED; /* Next instruction should be an CALLXn with operand 0 == regno. */ offset += xtensa_format_length (isa, fmt); xtensa_insnbuf_from_chars (isa, insnbuf, buf + offset, bufsize - offset); fmt = xtensa_format_decode (isa, insnbuf); if (fmt == XTENSA_UNDEFINED || xtensa_format_get_slot (isa, fmt, 0, insnbuf, slotbuf)) return XTENSA_UNDEFINED; opcode = xtensa_opcode_decode (isa, fmt, 0, slotbuf); if (opcode == XTENSA_UNDEFINED || !is_indirect_call_opcode (opcode)) return XTENSA_UNDEFINED; if (xtensa_operand_get_field (isa, opcode, CALLN_SOURCE_OPERAND, fmt, 0, slotbuf, &call_regno) || xtensa_operand_decode (isa, opcode, CALLN_SOURCE_OPERAND, &call_regno)) return XTENSA_UNDEFINED; if (call_regno != regno) return XTENSA_UNDEFINED; return opcode; } /* Data structures used during relaxation. */ /* r_reloc: relocation values. */ /* Through the relaxation process, we need to keep track of the values that will result from evaluating relocations. The standard ELF relocation structure is not sufficient for this purpose because we're operating on multiple input files at once, so we need to know which input file a relocation refers to. The r_reloc structure thus records both the input file (bfd) and ELF relocation. For efficiency, an r_reloc also contains a "target_offset" field to cache the target-section-relative offset value that is represented by the relocation. The r_reloc also contains a virtual offset that allows multiple inserted literals to be placed at the same "address" with different offsets. */ typedef struct r_reloc_struct r_reloc; struct r_reloc_struct { bfd *abfd; Elf_Internal_Rela rela; bfd_vma target_offset; bfd_vma virtual_offset; }; /* The r_reloc structure is included by value in literal_value, but not every literal_value has an associated relocation -- some are simple constants. In such cases, we set all the fields in the r_reloc struct to zero. The r_reloc_is_const function should be used to detect this case. */ static bfd_boolean r_reloc_is_const (const r_reloc *r_rel) { return (r_rel->abfd == NULL); } static bfd_vma r_reloc_get_target_offset (const r_reloc *r_rel) { bfd_vma target_offset; unsigned long r_symndx; BFD_ASSERT (!r_reloc_is_const (r_rel)); r_symndx = ELF32_R_SYM (r_rel->rela.r_info); target_offset = get_elf_r_symndx_offset (r_rel->abfd, r_symndx); return (target_offset + r_rel->rela.r_addend); } static struct elf_link_hash_entry * r_reloc_get_hash_entry (const r_reloc *r_rel) { unsigned long r_symndx = ELF32_R_SYM (r_rel->rela.r_info); return get_elf_r_symndx_hash_entry (r_rel->abfd, r_symndx); } static asection * r_reloc_get_section (const r_reloc *r_rel) { unsigned long r_symndx = ELF32_R_SYM (r_rel->rela.r_info); return get_elf_r_symndx_section (r_rel->abfd, r_symndx); } static bfd_boolean r_reloc_is_defined (const r_reloc *r_rel) { asection *sec; if (r_rel == NULL) return FALSE; sec = r_reloc_get_section (r_rel); if (sec == bfd_abs_section_ptr || sec == bfd_com_section_ptr || sec == bfd_und_section_ptr) return FALSE; return TRUE; } static void r_reloc_init (r_reloc *r_rel, bfd *abfd, Elf_Internal_Rela *irel, bfd_byte *contents, bfd_size_type content_length) { int r_type; reloc_howto_type *howto; if (irel) { r_rel->rela = *irel; r_rel->abfd = abfd; r_rel->target_offset = r_reloc_get_target_offset (r_rel); r_rel->virtual_offset = 0; r_type = ELF32_R_TYPE (r_rel->rela.r_info); howto = &elf_howto_table[r_type]; if (howto->partial_inplace) { bfd_vma inplace_val; BFD_ASSERT (r_rel->rela.r_offset < content_length); inplace_val = bfd_get_32 (abfd, &contents[r_rel->rela.r_offset]); r_rel->target_offset += inplace_val; } } else memset (r_rel, 0, sizeof (r_reloc)); } #if DEBUG static void print_r_reloc (FILE *fp, const r_reloc *r_rel) { if (r_reloc_is_defined (r_rel)) { asection *sec = r_reloc_get_section (r_rel); fprintf (fp, " %s(%s + ", sec->owner->filename, sec->name); } else if (r_reloc_get_hash_entry (r_rel)) fprintf (fp, " %s + ", r_reloc_get_hash_entry (r_rel)->root.root.string); else fprintf (fp, " ?? + "); fprintf_vma (fp, r_rel->target_offset); if (r_rel->virtual_offset) { fprintf (fp, " + "); fprintf_vma (fp, r_rel->virtual_offset); } fprintf (fp, ")"); } #endif /* DEBUG */ /* source_reloc: relocations that reference literals. */ /* To determine whether literals can be coalesced, we need to first record all the relocations that reference the literals. The source_reloc structure below is used for this purpose. The source_reloc entries are kept in a per-literal-section array, sorted by offset within the literal section (i.e., target offset). The source_sec and r_rel.rela.r_offset fields identify the source of the relocation. The r_rel field records the relocation value, i.e., the offset of the literal being referenced. The opnd field is needed to determine the range of the immediate field to which the relocation applies, so we can determine whether another literal with the same value is within range. The is_null field is true when the relocation is being removed (e.g., when an L32R is being removed due to a CALLX that is converted to a direct CALL). */ typedef struct source_reloc_struct source_reloc; struct source_reloc_struct { asection *source_sec; r_reloc r_rel; xtensa_opcode opcode; int opnd; bfd_boolean is_null; bfd_boolean is_abs_literal; }; static void init_source_reloc (source_reloc *reloc, asection *source_sec, const r_reloc *r_rel, xtensa_opcode opcode, int opnd, bfd_boolean is_abs_literal) { reloc->source_sec = source_sec; reloc->r_rel = *r_rel; reloc->opcode = opcode; reloc->opnd = opnd; reloc->is_null = FALSE; reloc->is_abs_literal = is_abs_literal; } /* Find the source_reloc for a particular source offset and relocation type. Note that the array is sorted by _target_ offset, so this is just a linear search. */ static source_reloc * find_source_reloc (source_reloc *src_relocs, int src_count, asection *sec, Elf_Internal_Rela *irel) { int i; for (i = 0; i < src_count; i++) { if (src_relocs[i].source_sec == sec && src_relocs[i].r_rel.rela.r_offset == irel->r_offset && (ELF32_R_TYPE (src_relocs[i].r_rel.rela.r_info) == ELF32_R_TYPE (irel->r_info))) return &src_relocs[i]; } return NULL; } static int source_reloc_compare (const void *ap, const void *bp) { const source_reloc *a = (const source_reloc *) ap; const source_reloc *b = (const source_reloc *) bp; if (a->r_rel.target_offset != b->r_rel.target_offset) return (a->r_rel.target_offset - b->r_rel.target_offset); /* We don't need to sort on these criteria for correctness, but enforcing a more strict ordering prevents unstable qsort from behaving differently with different implementations. Without the code below we get correct but different results on Solaris 2.7 and 2.8. We would like to always produce the same results no matter the host. */ if ((!a->is_null) - (!b->is_null)) return ((!a->is_null) - (!b->is_null)); return internal_reloc_compare (&a->r_rel.rela, &b->r_rel.rela); } /* Literal values and value hash tables. */ /* Literals with the same value can be coalesced. The literal_value structure records the value of a literal: the "r_rel" field holds the information from the relocation on the literal (if there is one) and the "value" field holds the contents of the literal word itself. The value_map structure records a literal value along with the location of a literal holding that value. The value_map hash table is indexed by the literal value, so that we can quickly check if a particular literal value has been seen before and is thus a candidate for coalescing. */ typedef struct literal_value_struct literal_value; typedef struct value_map_struct value_map; typedef struct value_map_hash_table_struct value_map_hash_table; struct literal_value_struct { r_reloc r_rel; unsigned long value; bfd_boolean is_abs_literal; }; struct value_map_struct { literal_value val; /* The literal value. */ r_reloc loc; /* Location of the literal. */ value_map *next; }; struct value_map_hash_table_struct { unsigned bucket_count; value_map **buckets; unsigned count; bfd_boolean has_last_loc; r_reloc last_loc; }; static void init_literal_value (literal_value *lit, const r_reloc *r_rel, unsigned long value, bfd_boolean is_abs_literal) { lit->r_rel = *r_rel; lit->value = value; lit->is_abs_literal = is_abs_literal; } static bfd_boolean literal_value_equal (const literal_value *src1, const literal_value *src2, bfd_boolean final_static_link) { struct elf_link_hash_entry *h1, *h2; if (r_reloc_is_const (&src1->r_rel) != r_reloc_is_const (&src2->r_rel)) return FALSE; if (r_reloc_is_const (&src1->r_rel)) return (src1->value == src2->value); if (ELF32_R_TYPE (src1->r_rel.rela.r_info) != ELF32_R_TYPE (src2->r_rel.rela.r_info)) return FALSE; if (src1->r_rel.target_offset != src2->r_rel.target_offset) return FALSE; if (src1->r_rel.virtual_offset != src2->r_rel.virtual_offset) return FALSE; if (src1->value != src2->value) return FALSE; /* Now check for the same section (if defined) or the same elf_hash (if undefined or weak). */ h1 = r_reloc_get_hash_entry (&src1->r_rel); h2 = r_reloc_get_hash_entry (&src2->r_rel); if (r_reloc_is_defined (&src1->r_rel) && (final_static_link || ((!h1 || h1->root.type != bfd_link_hash_defweak) && (!h2 || h2->root.type != bfd_link_hash_defweak)))) { if (r_reloc_get_section (&src1->r_rel) != r_reloc_get_section (&src2->r_rel)) return FALSE; } else { /* Require that the hash entries (i.e., symbols) be identical. */ if (h1 != h2 || h1 == 0) return FALSE; } if (src1->is_abs_literal != src2->is_abs_literal) return FALSE; return TRUE; } /* Must be power of 2. */ #define INITIAL_HASH_RELOC_BUCKET_COUNT 1024 static value_map_hash_table * value_map_hash_table_init (void) { value_map_hash_table *values; values = (value_map_hash_table *) bfd_zmalloc (sizeof (value_map_hash_table)); values->bucket_count = INITIAL_HASH_RELOC_BUCKET_COUNT; values->count = 0; values->buckets = (value_map **) bfd_zmalloc (sizeof (value_map *) * values->bucket_count); if (values->buckets == NULL) { free (values); return NULL; } values->has_last_loc = FALSE; return values; } static void value_map_hash_table_delete (value_map_hash_table *table) { free (table->buckets); free (table); } static unsigned hash_bfd_vma (bfd_vma val) { return (val >> 2) + (val >> 10); } static unsigned literal_value_hash (const literal_value *src) { unsigned hash_val; hash_val = hash_bfd_vma (src->value); if (!r_reloc_is_const (&src->r_rel)) { void *sec_or_hash; hash_val += hash_bfd_vma (src->is_abs_literal * 1000); hash_val += hash_bfd_vma (src->r_rel.target_offset); hash_val += hash_bfd_vma (src->r_rel.virtual_offset); /* Now check for the same section and the same elf_hash. */ if (r_reloc_is_defined (&src->r_rel)) sec_or_hash = r_reloc_get_section (&src->r_rel); else sec_or_hash = r_reloc_get_hash_entry (&src->r_rel); hash_val += hash_bfd_vma ((bfd_vma) (size_t) sec_or_hash); } return hash_val; } /* Check if the specified literal_value has been seen before. */ static value_map * value_map_get_cached_value (value_map_hash_table *map, const literal_value *val, bfd_boolean final_static_link) { value_map *map_e; value_map *bucket; unsigned idx; idx = literal_value_hash (val); idx = idx & (map->bucket_count - 1); bucket = map->buckets[idx]; for (map_e = bucket; map_e; map_e = map_e->next) { if (literal_value_equal (&map_e->val, val, final_static_link)) return map_e; } return NULL; } /* Record a new literal value. It is illegal to call this if VALUE already has an entry here. */ static value_map * add_value_map (value_map_hash_table *map, const literal_value *val, const r_reloc *loc, bfd_boolean final_static_link) { value_map **bucket_p; unsigned idx; value_map *val_e = (value_map *) bfd_zmalloc (sizeof (value_map)); if (val_e == NULL) { bfd_set_error (bfd_error_no_memory); return NULL; } BFD_ASSERT (!value_map_get_cached_value (map, val, final_static_link)); val_e->val = *val; val_e->loc = *loc; idx = literal_value_hash (val); idx = idx & (map->bucket_count - 1); bucket_p = &map->buckets[idx]; val_e->next = *bucket_p; *bucket_p = val_e; map->count++; /* FIXME: Consider resizing the hash table if we get too many entries. */ return val_e; } /* Lists of text actions (ta_) for narrowing, widening, longcall conversion, space fill, code & literal removal, etc. */ /* The following text actions are generated: "ta_remove_insn" remove an instruction or instructions "ta_remove_longcall" convert longcall to call "ta_convert_longcall" convert longcall to nop/call "ta_narrow_insn" narrow a wide instruction "ta_widen" widen a narrow instruction "ta_fill" add fill or remove fill removed < 0 is a fill; branches to the fill address will be changed to address + fill size (e.g., address - removed) removed >= 0 branches to the fill address will stay unchanged "ta_remove_literal" remove a literal; this action is indicated when a literal is removed or replaced. "ta_add_literal" insert a new literal; this action is indicated when a literal has been moved. It may use a virtual_offset because multiple literals can be placed at the same location. For each of these text actions, we also record the number of bytes removed by performing the text action. In the case of a "ta_widen" or a "ta_fill" that adds space, the removed_bytes will be negative. */ typedef struct text_action_struct text_action; typedef struct text_action_list_struct text_action_list; typedef enum text_action_enum_t text_action_t; enum text_action_enum_t { ta_none, ta_remove_insn, /* removed = -size */ ta_remove_longcall, /* removed = -size */ ta_convert_longcall, /* removed = 0 */ ta_narrow_insn, /* removed = -1 */ ta_widen_insn, /* removed = +1 */ ta_fill, /* removed = +size */ ta_remove_literal, ta_add_literal }; /* Structure for a text action record. */ struct text_action_struct { text_action_t action; asection *sec; /* Optional */ bfd_vma offset; bfd_vma virtual_offset; /* Zero except for adding literals. */ int removed_bytes; literal_value value; /* Only valid when adding literals. */ text_action *next; }; /* List of all of the actions taken on a text section. */ struct text_action_list_struct { text_action *head; }; static text_action * find_fill_action (text_action_list *l, asection *sec, bfd_vma offset) { text_action **m_p; /* It is not necessary to fill at the end of a section. */ if (sec->size == offset) return NULL; for (m_p = &l->head; *m_p && (*m_p)->offset <= offset; m_p = &(*m_p)->next) { text_action *t = *m_p; /* When the action is another fill at the same address, just increase the size. */ if (t->offset == offset && t->action == ta_fill) return t; } return NULL; } static int compute_removed_action_diff (const text_action *ta, asection *sec, bfd_vma offset, int removed, int removable_space) { int new_removed; int current_removed = 0; if (ta) current_removed = ta->removed_bytes; BFD_ASSERT (ta == NULL || ta->offset == offset); BFD_ASSERT (ta == NULL || ta->action == ta_fill); /* It is not necessary to fill at the end of a section. Clean this up. */ if (sec->size == offset) new_removed = removable_space - 0; else { int space; int added = -removed - current_removed; /* Ignore multiples of the section alignment. */ added = ((1 << sec->alignment_power) - 1) & added; new_removed = (-added); /* Modify for removable. */ space = removable_space - new_removed; new_removed = (removable_space - (((1 << sec->alignment_power) - 1) & space)); } return (new_removed - current_removed); } static void adjust_fill_action (text_action *ta, int fill_diff) { ta->removed_bytes += fill_diff; } /* Add a modification action to the text. For the case of adding or removing space, modify any current fill and assume that "unreachable_space" bytes can be freely contracted. Note that a negative removed value is a fill. */ static void text_action_add (text_action_list *l, text_action_t action, asection *sec, bfd_vma offset, int removed) { text_action **m_p; text_action *ta; /* It is not necessary to fill at the end of a section. */ if (action == ta_fill && sec->size == offset) return; /* It is not necessary to fill 0 bytes. */ if (action == ta_fill && removed == 0) return; for (m_p = &l->head; *m_p && (*m_p)->offset <= offset; m_p = &(*m_p)->next) { text_action *t = *m_p; if (action == ta_fill) { /* When the action is another fill at the same address, just increase the size. */ if (t->offset == offset && t->action == ta_fill) { t->removed_bytes += removed; return; } /* Fills need to happen before widens so that we don't insert fill bytes into the instruction stream. */ if (t->offset == offset && t->action == ta_widen_insn) break; } } /* Create a new record and fill it up. */ ta = (text_action *) bfd_zmalloc (sizeof (text_action)); ta->action = action; ta->sec = sec; ta->offset = offset; ta->removed_bytes = removed; ta->next = (*m_p); *m_p = ta; } static void text_action_add_literal (text_action_list *l, text_action_t action, const r_reloc *loc, const literal_value *value, int removed) { text_action **m_p; text_action *ta; asection *sec = r_reloc_get_section (loc); bfd_vma offset = loc->target_offset; bfd_vma virtual_offset = loc->virtual_offset; BFD_ASSERT (action == ta_add_literal); for (m_p = &l->head; *m_p != NULL; m_p = &(*m_p)->next) { if ((*m_p)->offset > offset && ((*m_p)->offset != offset || (*m_p)->virtual_offset > virtual_offset)) break; } /* Create a new record and fill it up. */ ta = (text_action *) bfd_zmalloc (sizeof (text_action)); ta->action = action; ta->sec = sec; ta->offset = offset; ta->virtual_offset = virtual_offset; ta->value = *value; ta->removed_bytes = removed; ta->next = (*m_p); *m_p = ta; } /* Find the total offset adjustment for the relaxations specified by text_actions, beginning from a particular starting action. This is typically used from offset_with_removed_text to search an entire list of actions, but it may also be called directly when adjusting adjacent offsets so that each search may begin where the previous one left off. */ static int removed_by_actions (text_action **p_start_action, bfd_vma offset, bfd_boolean before_fill) { text_action *r; int removed = 0; r = *p_start_action; while (r) { if (r->offset > offset) break; if (r->offset == offset && (before_fill || r->action != ta_fill || r->removed_bytes >= 0)) break; removed += r->removed_bytes; r = r->next; } *p_start_action = r; return removed; } static bfd_vma offset_with_removed_text (text_action_list *action_list, bfd_vma offset) { text_action *r = action_list->head; return offset - removed_by_actions (&r, offset, FALSE); } static unsigned action_list_count (text_action_list *action_list) { text_action *r = action_list->head; unsigned count = 0; for (r = action_list->head; r != NULL; r = r->next) { count++; } return count; } /* The find_insn_action routine will only find non-fill actions. */ static text_action * find_insn_action (text_action_list *action_list, bfd_vma offset) { text_action *t; for (t = action_list->head; t; t = t->next) { if (t->offset == offset) { switch (t->action) { case ta_none: case ta_fill: break; case ta_remove_insn: case ta_remove_longcall: case ta_convert_longcall: case ta_narrow_insn: case ta_widen_insn: return t; case ta_remove_literal: case ta_add_literal: BFD_ASSERT (0); break; } } } return NULL; } #if DEBUG static void print_action_list (FILE *fp, text_action_list *action_list) { text_action *r; fprintf (fp, "Text Action\n"); for (r = action_list->head; r != NULL; r = r->next) { const char *t = "unknown"; switch (r->action) { case ta_remove_insn: t = "remove_insn"; break; case ta_remove_longcall: t = "remove_longcall"; break; case ta_convert_longcall: t = "convert_longcall"; break; case ta_narrow_insn: t = "narrow_insn"; break; case ta_widen_insn: t = "widen_insn"; break; case ta_fill: t = "fill"; break; case ta_none: t = "none"; break; case ta_remove_literal: t = "remove_literal"; break; case ta_add_literal: t = "add_literal"; break; } fprintf (fp, "%s: %s[0x%lx] \"%s\" %d\n", r->sec->owner->filename, r->sec->name, (unsigned long) r->offset, t, r->removed_bytes); } } #endif /* DEBUG */ /* Lists of literals being coalesced or removed. */ /* In the usual case, the literal identified by "from" is being coalesced with another literal identified by "to". If the literal is unused and is being removed altogether, "to.abfd" will be NULL. The removed_literal entries are kept on a per-section list, sorted by the "from" offset field. */ typedef struct removed_literal_struct removed_literal; typedef struct removed_literal_list_struct removed_literal_list; struct removed_literal_struct { r_reloc from; r_reloc to; removed_literal *next; }; struct removed_literal_list_struct { removed_literal *head; removed_literal *tail; }; /* Record that the literal at "from" is being removed. If "to" is not NULL, the "from" literal is being coalesced with the "to" literal. */ static void add_removed_literal (removed_literal_list *removed_list, const r_reloc *from, const r_reloc *to) { removed_literal *r, *new_r, *next_r; new_r = (removed_literal *) bfd_zmalloc (sizeof (removed_literal)); new_r->from = *from; if (to) new_r->to = *to; else new_r->to.abfd = NULL; new_r->next = NULL; r = removed_list->head; if (r == NULL) { removed_list->head = new_r; removed_list->tail = new_r; } /* Special check for common case of append. */ else if (removed_list->tail->from.target_offset < from->target_offset) { removed_list->tail->next = new_r; removed_list->tail = new_r; } else { while (r->from.target_offset < from->target_offset && r->next) { r = r->next; } next_r = r->next; r->next = new_r; new_r->next = next_r; if (next_r == NULL) removed_list->tail = new_r; } } /* Check if the list of removed literals contains an entry for the given address. Return the entry if found. */ static removed_literal * find_removed_literal (removed_literal_list *removed_list, bfd_vma addr) { removed_literal *r = removed_list->head; while (r && r->from.target_offset < addr) r = r->next; if (r && r->from.target_offset == addr) return r; return NULL; } #if DEBUG static void print_removed_literals (FILE *fp, removed_literal_list *removed_list) { removed_literal *r; r = removed_list->head; if (r) fprintf (fp, "Removed Literals\n"); for (; r != NULL; r = r->next) { print_r_reloc (fp, &r->from); fprintf (fp, " => "); if (r->to.abfd == NULL) fprintf (fp, "REMOVED"); else print_r_reloc (fp, &r->to); fprintf (fp, "\n"); } } #endif /* DEBUG */ /* Per-section data for relaxation. */ typedef struct reloc_bfd_fix_struct reloc_bfd_fix; struct xtensa_relax_info_struct { bfd_boolean is_relaxable_literal_section; bfd_boolean is_relaxable_asm_section; int visited; /* Number of times visited. */ source_reloc *src_relocs; /* Array[src_count]. */ int src_count; int src_next; /* Next src_relocs entry to assign. */ removed_literal_list removed_list; text_action_list action_list; reloc_bfd_fix *fix_list; reloc_bfd_fix *fix_array; unsigned fix_array_count; /* Support for expanding the reloc array that is stored in the section structure. If the relocations have been reallocated, the newly allocated relocations will be referenced here along with the actual size allocated. The relocation count will always be found in the section structure. */ Elf_Internal_Rela *allocated_relocs; unsigned relocs_count; unsigned allocated_relocs_count; }; struct elf_xtensa_section_data { struct bfd_elf_section_data elf; xtensa_relax_info relax_info; }; static bfd_boolean elf_xtensa_new_section_hook (bfd *abfd, asection *sec) { if (!sec->used_by_bfd) { struct elf_xtensa_section_data *sdata; bfd_size_type amt = sizeof (*sdata); sdata = bfd_zalloc (abfd, amt); if (sdata == NULL) return FALSE; sec->used_by_bfd = sdata; } return _bfd_elf_new_section_hook (abfd, sec); } static xtensa_relax_info * get_xtensa_relax_info (asection *sec) { struct elf_xtensa_section_data *section_data; /* No info available if no section or if it is an output section. */ if (!sec || sec == sec->output_section) return NULL; section_data = (struct elf_xtensa_section_data *) elf_section_data (sec); return §ion_data->relax_info; } static void init_xtensa_relax_info (asection *sec) { xtensa_relax_info *relax_info = get_xtensa_relax_info (sec); relax_info->is_relaxable_literal_section = FALSE; relax_info->is_relaxable_asm_section = FALSE; relax_info->visited = 0; relax_info->src_relocs = NULL; relax_info->src_count = 0; relax_info->src_next = 0; relax_info->removed_list.head = NULL; relax_info->removed_list.tail = NULL; relax_info->action_list.head = NULL; relax_info->fix_list = NULL; relax_info->fix_array = NULL; relax_info->fix_array_count = 0; relax_info->allocated_relocs = NULL; relax_info->relocs_count = 0; relax_info->allocated_relocs_count = 0; } /* Coalescing literals may require a relocation to refer to a section in a different input file, but the standard relocation information cannot express that. Instead, the reloc_bfd_fix structures are used to "fix" the relocations that refer to sections in other input files. These structures are kept on per-section lists. The "src_type" field records the relocation type in case there are multiple relocations on the same location. FIXME: This is ugly; an alternative might be to add new symbols with the "owner" field to some other input file. */ struct reloc_bfd_fix_struct { asection *src_sec; bfd_vma src_offset; unsigned src_type; /* Relocation type. */ asection *target_sec; bfd_vma target_offset; bfd_boolean translated; reloc_bfd_fix *next; }; static reloc_bfd_fix * reloc_bfd_fix_init (asection *src_sec, bfd_vma src_offset, unsigned src_type, asection *target_sec, bfd_vma target_offset, bfd_boolean translated) { reloc_bfd_fix *fix; fix = (reloc_bfd_fix *) bfd_malloc (sizeof (reloc_bfd_fix)); fix->src_sec = src_sec; fix->src_offset = src_offset; fix->src_type = src_type; fix->target_sec = target_sec; fix->target_offset = target_offset; fix->translated = translated; return fix; } static void add_fix (asection *src_sec, reloc_bfd_fix *fix) { xtensa_relax_info *relax_info; relax_info = get_xtensa_relax_info (src_sec); fix->next = relax_info->fix_list; relax_info->fix_list = fix; } static int fix_compare (const void *ap, const void *bp) { const reloc_bfd_fix *a = (const reloc_bfd_fix *) ap; const reloc_bfd_fix *b = (const reloc_bfd_fix *) bp; if (a->src_offset != b->src_offset) return (a->src_offset - b->src_offset); return (a->src_type - b->src_type); } static void cache_fix_array (asection *sec) { unsigned i, count = 0; reloc_bfd_fix *r; xtensa_relax_info *relax_info = get_xtensa_relax_info (sec); if (relax_info == NULL) return; if (relax_info->fix_list == NULL) return; for (r = relax_info->fix_list; r != NULL; r = r->next) count++; relax_info->fix_array = (reloc_bfd_fix *) bfd_malloc (sizeof (reloc_bfd_fix) * count); relax_info->fix_array_count = count; r = relax_info->fix_list; for (i = 0; i < count; i++, r = r->next) { relax_info->fix_array[count - 1 - i] = *r; relax_info->fix_array[count - 1 - i].next = NULL; } qsort (relax_info->fix_array, relax_info->fix_array_count, sizeof (reloc_bfd_fix), fix_compare); } static reloc_bfd_fix * get_bfd_fix (asection *sec, bfd_vma offset, unsigned type) { xtensa_relax_info *relax_info = get_xtensa_relax_info (sec); reloc_bfd_fix *rv; reloc_bfd_fix key; if (relax_info == NULL) return NULL; if (relax_info->fix_list == NULL) return NULL; if (relax_info->fix_array == NULL) cache_fix_array (sec); key.src_offset = offset; key.src_type = type; rv = bsearch (&key, relax_info->fix_array, relax_info->fix_array_count, sizeof (reloc_bfd_fix), fix_compare); return rv; } /* Section caching. */ typedef struct section_cache_struct section_cache_t; struct section_cache_struct { asection *sec; bfd_byte *contents; /* Cache of the section contents. */ bfd_size_type content_length; property_table_entry *ptbl; /* Cache of the section property table. */ unsigned pte_count; Elf_Internal_Rela *relocs; /* Cache of the section relocations. */ unsigned reloc_count; }; static void init_section_cache (section_cache_t *sec_cache) { memset (sec_cache, 0, sizeof (*sec_cache)); } static void clear_section_cache (section_cache_t *sec_cache) { if (sec_cache->sec) { release_contents (sec_cache->sec, sec_cache->contents); release_internal_relocs (sec_cache->sec, sec_cache->relocs); if (sec_cache->ptbl) free (sec_cache->ptbl); memset (sec_cache, 0, sizeof (sec_cache)); } } static bfd_boolean section_cache_section (section_cache_t *sec_cache, asection *sec, struct bfd_link_info *link_info) { bfd *abfd; property_table_entry *prop_table = NULL; int ptblsize = 0; bfd_byte *contents = NULL; Elf_Internal_Rela *internal_relocs = NULL; bfd_size_type sec_size; if (sec == NULL) return FALSE; if (sec == sec_cache->sec) return TRUE; abfd = sec->owner; sec_size = bfd_get_section_limit (abfd, sec); /* Get the contents. */ contents = retrieve_contents (abfd, sec, link_info->keep_memory); if (contents == NULL && sec_size != 0) goto err; /* Get the relocations. */ internal_relocs = retrieve_internal_relocs (abfd, sec, link_info->keep_memory); /* Get the entry table. */ ptblsize = xtensa_read_table_entries (abfd, sec, &prop_table, XTENSA_PROP_SEC_NAME, FALSE); if (ptblsize < 0) goto err; /* Fill in the new section cache. */ clear_section_cache (sec_cache); memset (sec_cache, 0, sizeof (sec_cache)); sec_cache->sec = sec; sec_cache->contents = contents; sec_cache->content_length = sec_size; sec_cache->relocs = internal_relocs; sec_cache->reloc_count = sec->reloc_count; sec_cache->pte_count = ptblsize; sec_cache->ptbl = prop_table; return TRUE; err: release_contents (sec, contents); release_internal_relocs (sec, internal_relocs); if (prop_table) free (prop_table); return FALSE; } /* Extended basic blocks. */ /* An ebb_struct represents an Extended Basic Block. Within this range, we guarantee that all instructions are decodable, the property table entries are contiguous, and no property table specifies a segment that cannot have instructions moved. This structure contains caches of the contents, property table and relocations for the specified section for easy use. The range is specified by ranges of indices for the byte offset, property table offsets and relocation offsets. These must be consistent. */ typedef struct ebb_struct ebb_t; struct ebb_struct { asection *sec; bfd_byte *contents; /* Cache of the section contents. */ bfd_size_type content_length; property_table_entry *ptbl; /* Cache of the section property table. */ unsigned pte_count; Elf_Internal_Rela *relocs; /* Cache of the section relocations. */ unsigned reloc_count; bfd_vma start_offset; /* Offset in section. */ unsigned start_ptbl_idx; /* Offset in the property table. */ unsigned start_reloc_idx; /* Offset in the relocations. */ bfd_vma end_offset; unsigned end_ptbl_idx; unsigned end_reloc_idx; bfd_boolean ends_section; /* Is this the last ebb in a section? */ /* The unreachable property table at the end of this set of blocks; NULL if the end is not an unreachable block. */ property_table_entry *ends_unreachable; }; enum ebb_target_enum { EBB_NO_ALIGN = 0, EBB_DESIRE_TGT_ALIGN, EBB_REQUIRE_TGT_ALIGN, EBB_REQUIRE_LOOP_ALIGN, EBB_REQUIRE_ALIGN }; /* proposed_action_struct is similar to the text_action_struct except that is represents a potential transformation, not one that will occur. We build a list of these for an extended basic block and use them to compute the actual actions desired. We must be careful that the entire set of actual actions we perform do not break any relocations that would fit if the actions were not performed. */ typedef struct proposed_action_struct proposed_action; struct proposed_action_struct { enum ebb_target_enum align_type; /* for the target alignment */ bfd_vma alignment_pow; text_action_t action; bfd_vma offset; int removed_bytes; bfd_boolean do_action; /* If false, then we will not perform the action. */ }; /* The ebb_constraint_struct keeps a set of proposed actions for an extended basic block. */ typedef struct ebb_constraint_struct ebb_constraint; struct ebb_constraint_struct { ebb_t ebb; bfd_boolean start_movable; /* Bytes of extra space at the beginning if movable. */ int start_extra_space; enum ebb_target_enum start_align; bfd_boolean end_movable; /* Bytes of extra space at the end if movable. */ int end_extra_space; unsigned action_count; unsigned action_allocated; /* Array of proposed actions. */ proposed_action *actions; /* Action alignments -- one for each proposed action. */ enum ebb_target_enum *action_aligns; }; static void init_ebb_constraint (ebb_constraint *c) { memset (c, 0, sizeof (ebb_constraint)); } static void free_ebb_constraint (ebb_constraint *c) { if (c->actions) free (c->actions); } static void init_ebb (ebb_t *ebb, asection *sec, bfd_byte *contents, bfd_size_type content_length, property_table_entry *prop_table, unsigned ptblsize, Elf_Internal_Rela *internal_relocs, unsigned reloc_count) { memset (ebb, 0, sizeof (ebb_t)); ebb->sec = sec; ebb->contents = contents; ebb->content_length = content_length; ebb->ptbl = prop_table; ebb->pte_count = ptblsize; ebb->relocs = internal_relocs; ebb->reloc_count = reloc_count; ebb->start_offset = 0; ebb->end_offset = ebb->content_length - 1; ebb->start_ptbl_idx = 0; ebb->end_ptbl_idx = ptblsize; ebb->start_reloc_idx = 0; ebb->end_reloc_idx = reloc_count; } /* Extend the ebb to all decodable contiguous sections. The algorithm for building a basic block around an instruction is to push it forward until we hit the end of a section, an unreachable block or a block that cannot be transformed. Then we push it backwards searching for similar conditions. */ static bfd_boolean extend_ebb_bounds_forward (ebb_t *); static bfd_boolean extend_ebb_bounds_backward (ebb_t *); static bfd_size_type insn_block_decodable_len (bfd_byte *, bfd_size_type, bfd_vma, bfd_size_type); static bfd_boolean extend_ebb_bounds (ebb_t *ebb) { if (!extend_ebb_bounds_forward (ebb)) return FALSE; if (!extend_ebb_bounds_backward (ebb)) return FALSE; return TRUE; } static bfd_boolean extend_ebb_bounds_forward (ebb_t *ebb) { property_table_entry *the_entry, *new_entry; the_entry = &ebb->ptbl[ebb->end_ptbl_idx]; /* Stop when (1) we cannot decode an instruction, (2) we are at the end of the property tables, (3) we hit a non-contiguous property table entry, (4) we hit a NO_TRANSFORM region. */ while (1) { bfd_vma entry_end; bfd_size_type insn_block_len; entry_end = the_entry->address - ebb->sec->vma + the_entry->size; insn_block_len = insn_block_decodable_len (ebb->contents, ebb->content_length, ebb->end_offset, entry_end - ebb->end_offset); if (insn_block_len != (entry_end - ebb->end_offset)) { (*_bfd_error_handler) (_("%B(%A+0x%lx): could not decode instruction; possible configuration mismatch"), ebb->sec->owner, ebb->sec, ebb->end_offset + insn_block_len); return FALSE; } ebb->end_offset += insn_block_len; if (ebb->end_offset == ebb->sec->size) ebb->ends_section = TRUE; /* Update the reloc counter. */ while (ebb->end_reloc_idx + 1 < ebb->reloc_count && (ebb->relocs[ebb->end_reloc_idx + 1].r_offset < ebb->end_offset)) { ebb->end_reloc_idx++; } if (ebb->end_ptbl_idx + 1 == ebb->pte_count) return TRUE; new_entry = &ebb->ptbl[ebb->end_ptbl_idx + 1]; if (((new_entry->flags & XTENSA_PROP_INSN) == 0) || ((new_entry->flags & XTENSA_PROP_NO_TRANSFORM) != 0) || ((the_entry->flags & XTENSA_PROP_ALIGN) != 0)) break; if (the_entry->address + the_entry->size != new_entry->address) break; the_entry = new_entry; ebb->end_ptbl_idx++; } /* Quick check for an unreachable or end of file just at the end. */ if (ebb->end_ptbl_idx + 1 == ebb->pte_count) { if (ebb->end_offset == ebb->content_length) ebb->ends_section = TRUE; } else { new_entry = &ebb->ptbl[ebb->end_ptbl_idx + 1]; if ((new_entry->flags & XTENSA_PROP_UNREACHABLE) != 0 && the_entry->address + the_entry->size == new_entry->address) ebb->ends_unreachable = new_entry; } /* Any other ending requires exact alignment. */ return TRUE; } static bfd_boolean extend_ebb_bounds_backward (ebb_t *ebb) { property_table_entry *the_entry, *new_entry; the_entry = &ebb->ptbl[ebb->start_ptbl_idx]; /* Stop when (1) we cannot decode the instructions in the current entry. (2) we are at the beginning of the property tables, (3) we hit a non-contiguous property table entry, (4) we hit a NO_TRANSFORM region. */ while (1) { bfd_vma block_begin; bfd_size_type insn_block_len; block_begin = the_entry->address - ebb->sec->vma; insn_block_len = insn_block_decodable_len (ebb->contents, ebb->content_length, block_begin, ebb->start_offset - block_begin); if (insn_block_len != ebb->start_offset - block_begin) { (*_bfd_error_handler) (_("%B(%A+0x%lx): could not decode instruction; possible configuration mismatch"), ebb->sec->owner, ebb->sec, ebb->end_offset + insn_block_len); return FALSE; } ebb->start_offset -= insn_block_len; /* Update the reloc counter. */ while (ebb->start_reloc_idx > 0 && (ebb->relocs[ebb->start_reloc_idx - 1].r_offset >= ebb->start_offset)) { ebb->start_reloc_idx--; } if (ebb->start_ptbl_idx == 0) return TRUE; new_entry = &ebb->ptbl[ebb->start_ptbl_idx - 1]; if ((new_entry->flags & XTENSA_PROP_INSN) == 0 || ((new_entry->flags & XTENSA_PROP_NO_TRANSFORM) != 0) || ((new_entry->flags & XTENSA_PROP_ALIGN) != 0)) return TRUE; if (new_entry->address + new_entry->size != the_entry->address) return TRUE; the_entry = new_entry; ebb->start_ptbl_idx--; } return TRUE; } static bfd_size_type insn_block_decodable_len (bfd_byte *contents, bfd_size_type content_len, bfd_vma block_offset, bfd_size_type block_len) { bfd_vma offset = block_offset; while (offset < block_offset + block_len) { bfd_size_type insn_len = 0; insn_len = insn_decode_len (contents, content_len, offset); if (insn_len == 0) return (offset - block_offset); offset += insn_len; } return (offset - block_offset); } static void ebb_propose_action (ebb_constraint *c, enum ebb_target_enum align_type, bfd_vma alignment_pow, text_action_t action, bfd_vma offset, int removed_bytes, bfd_boolean do_action) { proposed_action *act; if (c->action_allocated <= c->action_count) { unsigned new_allocated, i; proposed_action *new_actions; new_allocated = (c->action_count + 2) * 2; new_actions = (proposed_action *) bfd_zmalloc (sizeof (proposed_action) * new_allocated); for (i = 0; i < c->action_count; i++) new_actions[i] = c->actions[i]; if (c->actions) free (c->actions); c->actions = new_actions; c->action_allocated = new_allocated; } act = &c->actions[c->action_count]; act->align_type = align_type; act->alignment_pow = alignment_pow; act->action = action; act->offset = offset; act->removed_bytes = removed_bytes; act->do_action = do_action; c->action_count++; } /* Access to internal relocations, section contents and symbols. */ /* During relaxation, we need to modify relocations, section contents, and symbol definitions, and we need to keep the original values from being reloaded from the input files, i.e., we need to "pin" the modified values in memory. We also want to continue to observe the setting of the "keep-memory" flag. The following functions wrap the standard BFD functions to take care of this for us. */ static Elf_Internal_Rela * retrieve_internal_relocs (bfd *abfd, asection *sec, bfd_boolean keep_memory) { Elf_Internal_Rela *internal_relocs; if ((sec->flags & SEC_LINKER_CREATED) != 0) return NULL; internal_relocs = elf_section_data (sec)->relocs; if (internal_relocs == NULL) internal_relocs = (_bfd_elf_link_read_relocs (abfd, sec, NULL, NULL, keep_memory)); return internal_relocs; } static void pin_internal_relocs (asection *sec, Elf_Internal_Rela *internal_relocs) { elf_section_data (sec)->relocs = internal_relocs; } static void release_internal_relocs (asection *sec, Elf_Internal_Rela *internal_relocs) { if (internal_relocs && elf_section_data (sec)->relocs != internal_relocs) free (internal_relocs); } static bfd_byte * retrieve_contents (bfd *abfd, asection *sec, bfd_boolean keep_memory) { bfd_byte *contents; bfd_size_type sec_size; sec_size = bfd_get_section_limit (abfd, sec); contents = elf_section_data (sec)->this_hdr.contents; if (contents == NULL && sec_size != 0) { if (!bfd_malloc_and_get_section (abfd, sec, &contents)) { if (contents) free (contents); return NULL; } if (keep_memory) elf_section_data (sec)->this_hdr.contents = contents; } return contents; } static void pin_contents (asection *sec, bfd_byte *contents) { elf_section_data (sec)->this_hdr.contents = contents; } static void release_contents (asection *sec, bfd_byte *contents) { if (contents && elf_section_data (sec)->this_hdr.contents != contents) free (contents); } static Elf_Internal_Sym * retrieve_local_syms (bfd *input_bfd) { Elf_Internal_Shdr *symtab_hdr; Elf_Internal_Sym *isymbuf; size_t locsymcount; symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr; locsymcount = symtab_hdr->sh_info; isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents; if (isymbuf == NULL && locsymcount != 0) isymbuf = bfd_elf_get_elf_syms (input_bfd, symtab_hdr, locsymcount, 0, NULL, NULL, NULL); /* Save the symbols for this input file so they won't be read again. */ if (isymbuf && isymbuf != (Elf_Internal_Sym *) symtab_hdr->contents) symtab_hdr->contents = (unsigned char *) isymbuf; return isymbuf; } /* Code for link-time relaxation. */ /* Initialization for relaxation: */ static bfd_boolean analyze_relocations (struct bfd_link_info *); static bfd_boolean find_relaxable_sections (bfd *, asection *, struct bfd_link_info *, bfd_boolean *); static bfd_boolean collect_source_relocs (bfd *, asection *, struct bfd_link_info *); static bfd_boolean is_resolvable_asm_expansion (bfd *, asection *, bfd_byte *, Elf_Internal_Rela *, struct bfd_link_info *, bfd_boolean *); static Elf_Internal_Rela *find_associated_l32r_irel (bfd *, asection *, bfd_byte *, Elf_Internal_Rela *, Elf_Internal_Rela *); static bfd_boolean compute_text_actions (bfd *, asection *, struct bfd_link_info *); static bfd_boolean compute_ebb_proposed_actions (ebb_constraint *); static bfd_boolean compute_ebb_actions (ebb_constraint *); static bfd_boolean check_section_ebb_pcrels_fit (bfd *, asection *, bfd_byte *, Elf_Internal_Rela *, const ebb_constraint *, const xtensa_opcode *); static bfd_boolean check_section_ebb_reduces (const ebb_constraint *); static void text_action_add_proposed (text_action_list *, const ebb_constraint *, asection *); static int compute_fill_extra_space (property_table_entry *); /* First pass: */ static bfd_boolean compute_removed_literals (bfd *, asection *, struct bfd_link_info *, value_map_hash_table *); static Elf_Internal_Rela *get_irel_at_offset (asection *, Elf_Internal_Rela *, bfd_vma); static bfd_boolean is_removable_literal (const source_reloc *, int, const source_reloc *, int, asection *, property_table_entry *, int); static bfd_boolean remove_dead_literal (bfd *, asection *, struct bfd_link_info *, Elf_Internal_Rela *, Elf_Internal_Rela *, source_reloc *, property_table_entry *, int); static bfd_boolean identify_literal_placement (bfd *, asection *, bfd_byte *, struct bfd_link_info *, value_map_hash_table *, bfd_boolean *, Elf_Internal_Rela *, int, source_reloc *, property_table_entry *, int, section_cache_t *, bfd_boolean); static bfd_boolean relocations_reach (source_reloc *, int, const r_reloc *); static bfd_boolean coalesce_shared_literal (asection *, source_reloc *, property_table_entry *, int, value_map *); static bfd_boolean move_shared_literal (asection *, struct bfd_link_info *, source_reloc *, property_table_entry *, int, const r_reloc *, const literal_value *, section_cache_t *); /* Second pass: */ static bfd_boolean relax_section (bfd *, asection *, struct bfd_link_info *); static bfd_boolean translate_section_fixes (asection *); static bfd_boolean translate_reloc_bfd_fix (reloc_bfd_fix *); static asection *translate_reloc (const r_reloc *, r_reloc *, asection *); static void shrink_dynamic_reloc_sections (struct bfd_link_info *, bfd *, asection *, Elf_Internal_Rela *); static bfd_boolean move_literal (bfd *, struct bfd_link_info *, asection *, bfd_vma, bfd_byte *, xtensa_relax_info *, Elf_Internal_Rela **, const literal_value *); static bfd_boolean relax_property_section (bfd *, asection *, struct bfd_link_info *); /* Third pass: */ static bfd_boolean relax_section_symbols (bfd *, asection *); static bfd_boolean elf_xtensa_relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info, bfd_boolean *again) { static value_map_hash_table *values = NULL; static bfd_boolean relocations_analyzed = FALSE; xtensa_relax_info *relax_info; if (!relocations_analyzed) { /* Do some overall initialization for relaxation. */ values = value_map_hash_table_init (); if (values == NULL) return FALSE; relaxing_section = TRUE; if (!analyze_relocations (link_info)) return FALSE; relocations_analyzed = TRUE; } *again = FALSE; /* Don't mess with linker-created sections. */ if ((sec->flags & SEC_LINKER_CREATED) != 0) return TRUE; relax_info = get_xtensa_relax_info (sec); BFD_ASSERT (relax_info != NULL); switch (relax_info->visited) { case 0: /* Note: It would be nice to fold this pass into analyze_relocations, but it is important for this step that the sections be examined in link order. */ if (!compute_removed_literals (abfd, sec, link_info, values)) return FALSE; *again = TRUE; break; case 1: if (values) value_map_hash_table_delete (values); values = NULL; if (!relax_section (abfd, sec, link_info)) return FALSE; *again = TRUE; break; case 2: if (!relax_section_symbols (abfd, sec)) return FALSE; break; } relax_info->visited++; return TRUE; } /* Initialization for relaxation. */ /* This function is called once at the start of relaxation. It scans all the input sections and marks the ones that are relaxable (i.e., literal sections with L32R relocations against them), and then collects source_reloc information for all the relocations against those relaxable sections. During this process, it also detects longcalls, i.e., calls relaxed by the assembler into indirect calls, that can be optimized back into direct calls. Within each extended basic block (ebb) containing an optimized longcall, it computes a set of "text actions" that can be performed to remove the L32R associated with the longcall while optionally preserving branch target alignments. */ static bfd_boolean analyze_relocations (struct bfd_link_info *link_info) { bfd *abfd; asection *sec; bfd_boolean is_relaxable = FALSE; /* Initialize the per-section relaxation info. */ for (abfd = link_info->input_bfds; abfd != NULL; abfd = abfd->link_next) for (sec = abfd->sections; sec != NULL; sec = sec->next) { init_xtensa_relax_info (sec); } /* Mark relaxable sections (and count relocations against each one). */ for (abfd = link_info->input_bfds; abfd != NULL; abfd = abfd->link_next) for (sec = abfd->sections; sec != NULL; sec = sec->next) { if (!find_relaxable_sections (abfd, sec, link_info, &is_relaxable)) return FALSE; } /* Bail out if there are no relaxable sections. */ if (!is_relaxable) return TRUE; /* Allocate space for source_relocs. */ for (abfd = link_info->input_bfds; abfd != NULL; abfd = abfd->link_next) for (sec = abfd->sections; sec != NULL; sec = sec->next) { xtensa_relax_info *relax_info; relax_info = get_xtensa_relax_info (sec); if (relax_info->is_relaxable_literal_section || relax_info->is_relaxable_asm_section) { relax_info->src_relocs = (source_reloc *) bfd_malloc (relax_info->src_count * sizeof (source_reloc)); } else relax_info->src_count = 0; } /* Collect info on relocations against each relaxable section. */ for (abfd = link_info->input_bfds; abfd != NULL; abfd = abfd->link_next) for (sec = abfd->sections; sec != NULL; sec = sec->next) { if (!collect_source_relocs (abfd, sec, link_info)) return FALSE; } /* Compute the text actions. */ for (abfd = link_info->input_bfds; abfd != NULL; abfd = abfd->link_next) for (sec = abfd->sections; sec != NULL; sec = sec->next) { if (!compute_text_actions (abfd, sec, link_info)) return FALSE; } return TRUE; } /* Find all the sections that might be relaxed. The motivation for this pass is that collect_source_relocs() needs to record _all_ the relocations that target each relaxable section. That is expensive and unnecessary unless the target section is actually going to be relaxed. This pass identifies all such sections by checking if they have L32Rs pointing to them. In the process, the total number of relocations targeting each section is also counted so that we know how much space to allocate for source_relocs against each relaxable literal section. */ static bfd_boolean find_relaxable_sections (bfd *abfd, asection *sec, struct bfd_link_info *link_info, bfd_boolean *is_relaxable_p) { Elf_Internal_Rela *internal_relocs; bfd_byte *contents; bfd_boolean ok = TRUE; unsigned i; xtensa_relax_info *source_relax_info; bfd_boolean is_l32r_reloc; internal_relocs = retrieve_internal_relocs (abfd, sec, link_info->keep_memory); if (internal_relocs == NULL) return ok; contents = retrieve_contents (abfd, sec, link_info->keep_memory); if (contents == NULL && sec->size != 0) { ok = FALSE; goto error_return; } source_relax_info = get_xtensa_relax_info (sec); for (i = 0; i < sec->reloc_count; i++) { Elf_Internal_Rela *irel = &internal_relocs[i]; r_reloc r_rel; asection *target_sec; xtensa_relax_info *target_relax_info; /* If this section has not already been marked as "relaxable", and if it contains any ASM_EXPAND relocations (marking expanded longcalls) that can be optimized into direct calls, then mark the section as "relaxable". */ if (source_relax_info && !source_relax_info->is_relaxable_asm_section && ELF32_R_TYPE (irel->r_info) == R_XTENSA_ASM_EXPAND) { bfd_boolean is_reachable = FALSE; if (is_resolvable_asm_expansion (abfd, sec, contents, irel, link_info, &is_reachable) && is_reachable) { source_relax_info->is_relaxable_asm_section = TRUE; *is_relaxable_p = TRUE; } } r_reloc_init (&r_rel, abfd, irel, contents, bfd_get_section_limit (abfd, sec)); target_sec = r_reloc_get_section (&r_rel); target_relax_info = get_xtensa_relax_info (target_sec); if (!target_relax_info) continue; /* Count PC-relative operand relocations against the target section. Note: The conditions tested here must match the conditions under which init_source_reloc is called in collect_source_relocs(). */ is_l32r_reloc = FALSE; if (is_operand_relocation (ELF32_R_TYPE (irel->r_info))) { xtensa_opcode opcode = get_relocation_opcode (abfd, sec, contents, irel); if (opcode != XTENSA_UNDEFINED) { is_l32r_reloc = (opcode == get_l32r_opcode ()); if (!is_alt_relocation (ELF32_R_TYPE (irel->r_info)) || is_l32r_reloc) target_relax_info->src_count++; } } if (is_l32r_reloc && r_reloc_is_defined (&r_rel)) { /* Mark the target section as relaxable. */ target_relax_info->is_relaxable_literal_section = TRUE; *is_relaxable_p = TRUE; } } error_return: release_contents (sec, contents); release_internal_relocs (sec, internal_relocs); return ok; } /* Record _all_ the relocations that point to relaxable sections, and get rid of ASM_EXPAND relocs by either converting them to ASM_SIMPLIFY or by removing them. */ static bfd_boolean collect_source_relocs (bfd *abfd, asection *sec, struct bfd_link_info *link_info) { Elf_Internal_Rela *internal_relocs; bfd_byte *contents; bfd_boolean ok = TRUE; unsigned i; bfd_size_type sec_size; internal_relocs = retrieve_internal_relocs (abfd, sec, link_info->keep_memory); if (internal_relocs == NULL) return ok; sec_size = bfd_get_section_limit (abfd, sec); contents = retrieve_contents (abfd, sec, link_info->keep_memory); if (contents == NULL && sec_size != 0) { ok = FALSE; goto error_return; } /* Record relocations against relaxable literal sections. */ for (i = 0; i < sec->reloc_count; i++) { Elf_Internal_Rela *irel = &internal_relocs[i]; r_reloc r_rel; asection *target_sec; xtensa_relax_info *target_relax_info; r_reloc_init (&r_rel, abfd, irel, contents, sec_size); target_sec = r_reloc_get_section (&r_rel); target_relax_info = get_xtensa_relax_info (target_sec); if (target_relax_info && (target_relax_info->is_relaxable_literal_section || target_relax_info->is_relaxable_asm_section)) { xtensa_opcode opcode = XTENSA_UNDEFINED; int opnd = -1; bfd_boolean is_abs_literal = FALSE; if (is_alt_relocation (ELF32_R_TYPE (irel->r_info))) { /* None of the current alternate relocs are PC-relative, and only PC-relative relocs matter here. However, we still need to record the opcode for literal coalescing. */ opcode = get_relocation_opcode (abfd, sec, contents, irel); if (opcode == get_l32r_opcode ()) { is_abs_literal = TRUE; opnd = 1; } else opcode = XTENSA_UNDEFINED; } else if (is_operand_relocation (ELF32_R_TYPE (irel->r_info))) { opcode = get_relocation_opcode (abfd, sec, contents, irel); opnd = get_relocation_opnd (opcode, ELF32_R_TYPE (irel->r_info)); } if (opcode != XTENSA_UNDEFINED) { int src_next = target_relax_info->src_next++; source_reloc *s_reloc = &target_relax_info->src_relocs[src_next]; init_source_reloc (s_reloc, sec, &r_rel, opcode, opnd, is_abs_literal); } } } /* Now get rid of ASM_EXPAND relocations. At this point, the src_relocs array for the target literal section may still be incomplete, but it must at least contain the entries for the L32R relocations associated with ASM_EXPANDs because they were just added in the preceding loop over the relocations. */ for (i = 0; i < sec->reloc_count; i++) { Elf_Internal_Rela *irel = &internal_relocs[i]; bfd_boolean is_reachable; if (!is_resolvable_asm_expansion (abfd, sec, contents, irel, link_info, &is_reachable)) continue; if (is_reachable) { Elf_Internal_Rela *l32r_irel; r_reloc r_rel; asection *target_sec; xtensa_relax_info *target_relax_info; /* Mark the source_reloc for the L32R so that it will be removed in compute_removed_literals(), along with the associated literal. */ l32r_irel = find_associated_l32r_irel (abfd, sec, contents, irel, internal_relocs); if (l32r_irel == NULL) continue; r_reloc_init (&r_rel, abfd, l32r_irel, contents, sec_size); target_sec = r_reloc_get_section (&r_rel); target_relax_info = get_xtensa_relax_info (target_sec); if (target_relax_info && (target_relax_info->is_relaxable_literal_section || target_relax_info->is_relaxable_asm_section)) { source_reloc *s_reloc; /* Search the source_relocs for the entry corresponding to the l32r_irel. Note: The src_relocs array is not yet sorted, but it wouldn't matter anyway because we're searching by source offset instead of target offset. */ s_reloc = find_source_reloc (target_relax_info->src_relocs, target_relax_info->src_next, sec, l32r_irel); BFD_ASSERT (s_reloc); s_reloc->is_null = TRUE; } /* Convert this reloc to ASM_SIMPLIFY. */ irel->r_info = ELF32_R_INFO (ELF32_R_SYM (irel->r_info), R_XTENSA_ASM_SIMPLIFY); l32r_irel->r_info = ELF32_R_INFO (0, R_XTENSA_NONE); pin_internal_relocs (sec, internal_relocs); } else { /* It is resolvable but doesn't reach. We resolve now by eliminating the relocation -- the call will remain expanded into L32R/CALLX. */ irel->r_info = ELF32_R_INFO (0, R_XTENSA_NONE); pin_internal_relocs (sec, internal_relocs); } } error_return: release_contents (sec, contents); release_internal_relocs (sec, internal_relocs); return ok; } /* Return TRUE if the asm expansion can be resolved. Generally it can be resolved on a final link or when a partial link locates it in the same section as the target. Set "is_reachable" flag if the target of the call is within the range of a direct call, given the current VMA for this section and the target section. */ bfd_boolean is_resolvable_asm_expansion (bfd *abfd, asection *sec, bfd_byte *contents, Elf_Internal_Rela *irel, struct bfd_link_info *link_info, bfd_boolean *is_reachable_p) { asection *target_sec; bfd_vma target_offset; r_reloc r_rel; xtensa_opcode opcode, direct_call_opcode; bfd_vma self_address; bfd_vma dest_address; bfd_boolean uses_l32r; bfd_size_type sec_size; *is_reachable_p = FALSE; if (contents == NULL) return FALSE; if (ELF32_R_TYPE (irel->r_info) != R_XTENSA_ASM_EXPAND) return FALSE; sec_size = bfd_get_section_limit (abfd, sec); opcode = get_expanded_call_opcode (contents + irel->r_offset, sec_size - irel->r_offset, &uses_l32r); /* Optimization of longcalls that use CONST16 is not yet implemented. */ if (!uses_l32r) return FALSE; direct_call_opcode = swap_callx_for_call_opcode (opcode); if (direct_call_opcode == XTENSA_UNDEFINED) return FALSE; /* Check and see that the target resolves. */ r_reloc_init (&r_rel, abfd, irel, contents, sec_size); if (!r_reloc_is_defined (&r_rel)) return FALSE; target_sec = r_reloc_get_section (&r_rel); target_offset = r_rel.target_offset; /* If the target is in a shared library, then it doesn't reach. This isn't supposed to come up because the compiler should never generate non-PIC calls on systems that use shared libraries, but the linker shouldn't crash regardless. */ if (!target_sec->output_section) return FALSE; /* For relocatable sections, we can only simplify when the output section of the target is the same as the output section of the source. */ if (link_info->relocatable && (target_sec->output_section != sec->output_section || is_reloc_sym_weak (abfd, irel))) return FALSE; self_address = (sec->output_section->vma + sec->output_offset + irel->r_offset + 3); dest_address = (target_sec->output_section->vma + target_sec->output_offset + target_offset); *is_reachable_p = pcrel_reloc_fits (direct_call_opcode, 0, self_address, dest_address); if ((self_address >> CALL_SEGMENT_BITS) != (dest_address >> CALL_SEGMENT_BITS)) return FALSE; return TRUE; } static Elf_Internal_Rela * find_associated_l32r_irel (bfd *abfd, asection *sec, bfd_byte *contents, Elf_Internal_Rela *other_irel, Elf_Internal_Rela *internal_relocs) { unsigned i; for (i = 0; i < sec->reloc_count; i++) { Elf_Internal_Rela *irel = &internal_relocs[i]; if (irel == other_irel) continue; if (irel->r_offset != other_irel->r_offset) continue; if (is_l32r_relocation (abfd, sec, contents, irel)) return irel; } return NULL; } static xtensa_opcode * build_reloc_opcodes (bfd *abfd, asection *sec, bfd_byte *contents, Elf_Internal_Rela *internal_relocs) { unsigned i; xtensa_opcode *reloc_opcodes = (xtensa_opcode *) bfd_malloc (sizeof (xtensa_opcode) * sec->reloc_count); for (i = 0; i < sec->reloc_count; i++) { Elf_Internal_Rela *irel = &internal_relocs[i]; reloc_opcodes[i] = get_relocation_opcode (abfd, sec, contents, irel); } return reloc_opcodes; } /* The compute_text_actions function will build a list of potential transformation actions for code in the extended basic block of each longcall that is optimized to a direct call. From this list we generate a set of actions to actually perform that optimizes for space and, if not using size_opt, maintains branch target alignments. These actions to be performed are placed on a per-section list. The actual changes are performed by relax_section() in the second pass. */ bfd_boolean compute_text_actions (bfd *abfd, asection *sec, struct bfd_link_info *link_info) { xtensa_opcode *reloc_opcodes = NULL; xtensa_relax_info *relax_info; bfd_byte *contents; Elf_Internal_Rela *internal_relocs; bfd_boolean ok = TRUE; unsigned i; property_table_entry *prop_table = 0; int ptblsize = 0; bfd_size_type sec_size; relax_info = get_xtensa_relax_info (sec); BFD_ASSERT (relax_info); BFD_ASSERT (relax_info->src_next == relax_info->src_count); /* Do nothing if the section contains no optimized longcalls. */ if (!relax_info->is_relaxable_asm_section) return ok; internal_relocs = retrieve_internal_relocs (abfd, sec, link_info->keep_memory); if (internal_relocs) qsort (internal_relocs, sec->reloc_count, sizeof (Elf_Internal_Rela), internal_reloc_compare); sec_size = bfd_get_section_limit (abfd, sec); contents = retrieve_contents (abfd, sec, link_info->keep_memory); if (contents == NULL && sec_size != 0) { ok = FALSE; goto error_return; } ptblsize = xtensa_read_table_entries (abfd, sec, &prop_table, XTENSA_PROP_SEC_NAME, FALSE); if (ptblsize < 0) { ok = FALSE; goto error_return; } for (i = 0; i < sec->reloc_count; i++) { Elf_Internal_Rela *irel = &internal_relocs[i]; bfd_vma r_offset; property_table_entry *the_entry; int ptbl_idx; ebb_t *ebb; ebb_constraint ebb_table; bfd_size_type simplify_size; if (irel && ELF32_R_TYPE (irel->r_info) != R_XTENSA_ASM_SIMPLIFY) continue; r_offset = irel->r_offset; simplify_size = get_asm_simplify_size (contents, sec_size, r_offset); if (simplify_size == 0) { (*_bfd_error_handler) (_("%B(%A+0x%lx): could not decode instruction for XTENSA_ASM_SIMPLIFY relocation; possible configuration mismatch"), sec->owner, sec, r_offset); continue; } /* If the instruction table is not around, then don't do this relaxation. */ the_entry = elf_xtensa_find_property_entry (prop_table, ptblsize, sec->vma + irel->r_offset); if (the_entry == NULL || XTENSA_NO_NOP_REMOVAL) { text_action_add (&relax_info->action_list, ta_convert_longcall, sec, r_offset, 0); continue; } /* If the next longcall happens to be at the same address as an unreachable section of size 0, then skip forward. */ ptbl_idx = the_entry - prop_table; while ((the_entry->flags & XTENSA_PROP_UNREACHABLE) && the_entry->size == 0 && ptbl_idx + 1 < ptblsize && (prop_table[ptbl_idx + 1].address == prop_table[ptbl_idx].address)) { ptbl_idx++; the_entry++; } if (the_entry->flags & XTENSA_PROP_NO_TRANSFORM) /* NO_REORDER is OK */ continue; init_ebb_constraint (&ebb_table); ebb = &ebb_table.ebb; init_ebb (ebb, sec, contents, sec_size, prop_table, ptblsize, internal_relocs, sec->reloc_count); ebb->start_offset = r_offset + simplify_size; ebb->end_offset = r_offset + simplify_size; ebb->start_ptbl_idx = ptbl_idx; ebb->end_ptbl_idx = ptbl_idx; ebb->start_reloc_idx = i; ebb->end_reloc_idx = i; /* Precompute the opcode for each relocation. */ if (reloc_opcodes == NULL) reloc_opcodes = build_reloc_opcodes (abfd, sec, contents, internal_relocs); if (!extend_ebb_bounds (ebb) || !compute_ebb_proposed_actions (&ebb_table) || !compute_ebb_actions (&ebb_table) || !check_section_ebb_pcrels_fit (abfd, sec, contents, internal_relocs, &ebb_table, reloc_opcodes) || !check_section_ebb_reduces (&ebb_table)) { /* If anything goes wrong or we get unlucky and something does not fit, with our plan because of expansion between critical branches, just convert to a NOP. */ text_action_add (&relax_info->action_list, ta_convert_longcall, sec, r_offset, 0); i = ebb_table.ebb.end_reloc_idx; free_ebb_constraint (&ebb_table); continue; } text_action_add_proposed (&relax_info->action_list, &ebb_table, sec); /* Update the index so we do not go looking at the relocations we have already processed. */ i = ebb_table.ebb.end_reloc_idx; free_ebb_constraint (&ebb_table); } #if DEBUG if (relax_info->action_list.head) print_action_list (stderr, &relax_info->action_list); #endif error_return: release_contents (sec, contents); release_internal_relocs (sec, internal_relocs); if (prop_table) free (prop_table); if (reloc_opcodes) free (reloc_opcodes); return ok; } /* Do not widen an instruction if it is preceeded by a loop opcode. It might cause misalignment. */ static bfd_boolean prev_instr_is_a_loop (bfd_byte *contents, bfd_size_type content_length, bfd_size_type offset) { xtensa_opcode prev_opcode; if (offset < 3) return FALSE; prev_opcode = insn_decode_opcode (contents, content_length, offset-3, 0); return (xtensa_opcode_is_loop (xtensa_default_isa, prev_opcode) == 1); } /* Find all of the possible actions for an extended basic block. */ bfd_boolean compute_ebb_proposed_actions (ebb_constraint *ebb_table) { const ebb_t *ebb = &ebb_table->ebb; unsigned rel_idx = ebb->start_reloc_idx; property_table_entry *entry, *start_entry, *end_entry; bfd_vma offset = 0; xtensa_isa isa = xtensa_default_isa; xtensa_format fmt; static xtensa_insnbuf insnbuf = NULL; static xtensa_insnbuf slotbuf = NULL; if (insnbuf == NULL) { insnbuf = xtensa_insnbuf_alloc (isa); slotbuf = xtensa_insnbuf_alloc (isa); } start_entry = &ebb->ptbl[ebb->start_ptbl_idx]; end_entry = &ebb->ptbl[ebb->end_ptbl_idx]; for (entry = start_entry; entry <= end_entry; entry++) { bfd_vma start_offset, end_offset; bfd_size_type insn_len; start_offset = entry->address - ebb->sec->vma; end_offset = entry->address + entry->size - ebb->sec->vma; if (entry == start_entry) start_offset = ebb->start_offset; if (entry == end_entry) end_offset = ebb->end_offset; offset = start_offset; if (offset == entry->address - ebb->sec->vma && (entry->flags & XTENSA_PROP_INSN_BRANCH_TARGET) != 0) { enum ebb_target_enum align_type = EBB_DESIRE_TGT_ALIGN; BFD_ASSERT (offset != end_offset); if (offset == end_offset) return FALSE; insn_len = insn_decode_len (ebb->contents, ebb->content_length, offset); if (insn_len == 0) goto decode_error; if (check_branch_target_aligned_address (offset, insn_len)) align_type = EBB_REQUIRE_TGT_ALIGN; ebb_propose_action (ebb_table, align_type, 0, ta_none, offset, 0, TRUE); } while (offset != end_offset) { Elf_Internal_Rela *irel; xtensa_opcode opcode; while (rel_idx < ebb->end_reloc_idx && (ebb->relocs[rel_idx].r_offset < offset || (ebb->relocs[rel_idx].r_offset == offset && (ELF32_R_TYPE (ebb->relocs[rel_idx].r_info) != R_XTENSA_ASM_SIMPLIFY)))) rel_idx++; /* Check for longcall. */ irel = &ebb->relocs[rel_idx]; if (irel->r_offset == offset && ELF32_R_TYPE (irel->r_info) == R_XTENSA_ASM_SIMPLIFY) { bfd_size_type simplify_size; simplify_size = get_asm_simplify_size (ebb->contents, ebb->content_length, irel->r_offset); if (simplify_size == 0) goto decode_error; ebb_propose_action (ebb_table, EBB_NO_ALIGN, 0, ta_convert_longcall, offset, 0, TRUE); offset += simplify_size; continue; } if (offset + MIN_INSN_LENGTH > ebb->content_length) goto decode_error; xtensa_insnbuf_from_chars (isa, insnbuf, &ebb->contents[offset], ebb->content_length - offset); fmt = xtensa_format_decode (isa, insnbuf); if (fmt == XTENSA_UNDEFINED) goto decode_error; insn_len = xtensa_format_length (isa, fmt); if (insn_len == (bfd_size_type) XTENSA_UNDEFINED) goto decode_error; if (xtensa_format_num_slots (isa, fmt) != 1) { offset += insn_len; continue; } xtensa_format_get_slot (isa, fmt, 0, insnbuf, slotbuf); opcode = xtensa_opcode_decode (isa, fmt, 0, slotbuf); if (opcode == XTENSA_UNDEFINED) goto decode_error; if ((entry->flags & XTENSA_PROP_INSN_NO_DENSITY) == 0 && (entry->flags & XTENSA_PROP_NO_TRANSFORM) == 0 && can_narrow_instruction (slotbuf, fmt, opcode) != 0) { /* Add an instruction narrow action. */ ebb_propose_action (ebb_table, EBB_NO_ALIGN, 0, ta_narrow_insn, offset, 0, FALSE); } else if ((entry->flags & XTENSA_PROP_NO_TRANSFORM) == 0 && can_widen_instruction (slotbuf, fmt, opcode) != 0 && ! prev_instr_is_a_loop (ebb->contents, ebb->content_length, offset)) { /* Add an instruction widen action. */ ebb_propose_action (ebb_table, EBB_NO_ALIGN, 0, ta_widen_insn, offset, 0, FALSE); } else if (xtensa_opcode_is_loop (xtensa_default_isa, opcode) == 1) { /* Check for branch targets. */ ebb_propose_action (ebb_table, EBB_REQUIRE_LOOP_ALIGN, 0, ta_none, offset, 0, TRUE); } offset += insn_len; } } if (ebb->ends_unreachable) { ebb_propose_action (ebb_table, EBB_NO_ALIGN, 0, ta_fill, ebb->end_offset, 0, TRUE); } return TRUE; decode_error: (*_bfd_error_handler) (_("%B(%A+0x%lx): could not decode instruction; possible configuration mismatch"), ebb->sec->owner, ebb->sec, offset); return FALSE; } /* After all of the information has collected about the transformations possible in an EBB, compute the appropriate actions here in compute_ebb_actions. We still must check later to make sure that the actions do not break any relocations. The algorithm used here is pretty greedy. Basically, it removes as many no-ops as possible so that the end of the EBB has the same alignment characteristics as the original. First, it uses narrowing, then fill space at the end of the EBB, and finally widenings. If that does not work, it tries again with one fewer no-op removed. The optimization will only be performed if all of the branch targets that were aligned before transformation are also aligned after the transformation. When the size_opt flag is set, ignore the branch target alignments, narrow all wide instructions, and remove all no-ops unless the end of the EBB prevents it. */ bfd_boolean compute_ebb_actions (ebb_constraint *ebb_table) { unsigned i = 0; unsigned j; int removed_bytes = 0; ebb_t *ebb = &ebb_table->ebb; unsigned seg_idx_start = 0; unsigned seg_idx_end = 0; /* We perform this like the assembler relaxation algorithm: Start by assuming all instructions are narrow and all no-ops removed; then walk through.... */ /* For each segment of this that has a solid constraint, check to see if there are any combinations that will keep the constraint. If so, use it. */ for (seg_idx_end = 0; seg_idx_end < ebb_table->action_count; seg_idx_end++) { bfd_boolean requires_text_end_align = FALSE; unsigned longcall_count = 0; unsigned longcall_convert_count = 0; unsigned narrowable_count = 0; unsigned narrowable_convert_count = 0; unsigned widenable_count = 0; unsigned widenable_convert_count = 0; proposed_action *action = NULL; int align = (1 << ebb_table->ebb.sec->alignment_power); seg_idx_start = seg_idx_end; for (i = seg_idx_start; i < ebb_table->action_count; i++) { action = &ebb_table->actions[i]; if (action->action == ta_convert_longcall) longcall_count++; if (action->action == ta_narrow_insn) narrowable_count++; if (action->action == ta_widen_insn) widenable_count++; if (action->action == ta_fill) break; if (action->align_type == EBB_REQUIRE_LOOP_ALIGN) break; if (action->align_type == EBB_REQUIRE_TGT_ALIGN && !elf32xtensa_size_opt) break; } seg_idx_end = i; if (seg_idx_end == ebb_table->action_count && !ebb->ends_unreachable) requires_text_end_align = TRUE; if (elf32xtensa_size_opt && !requires_text_end_align && action->align_type != EBB_REQUIRE_LOOP_ALIGN && action->align_type != EBB_REQUIRE_TGT_ALIGN) { longcall_convert_count = longcall_count; narrowable_convert_count = narrowable_count; widenable_convert_count = 0; } else { /* There is a constraint. Convert the max number of longcalls. */ narrowable_convert_count = 0; longcall_convert_count = 0; widenable_convert_count = 0; for (j = 0; j < longcall_count; j++) { int removed = (longcall_count - j) * 3 & (align - 1); unsigned desire_narrow = (align - removed) & (align - 1); unsigned desire_widen = removed; if (desire_narrow <= narrowable_count) { narrowable_convert_count = desire_narrow; narrowable_convert_count += (align * ((narrowable_count - narrowable_convert_count) / align)); longcall_convert_count = (longcall_count - j); widenable_convert_count = 0; break; } if (desire_widen <= widenable_count && !elf32xtensa_size_opt) { narrowable_convert_count = 0; longcall_convert_count = longcall_count - j; widenable_convert_count = desire_widen; break; } } } /* Now the number of conversions are saved. Do them. */ for (i = seg_idx_start; i < seg_idx_end; i++) { action = &ebb_table->actions[i]; switch (action->action) { case ta_convert_longcall: if (longcall_convert_count != 0) { action->action = ta_remove_longcall; action->do_action = TRUE; action->removed_bytes += 3; longcall_convert_count--; } break; case ta_narrow_insn: if (narrowable_convert_count != 0) { action->do_action = TRUE; action->removed_bytes += 1; narrowable_convert_count--; } break; case ta_widen_insn: if (widenable_convert_count != 0) { action->do_action = TRUE; action->removed_bytes -= 1; widenable_convert_count--; } break; default: break; } } } /* Now we move on to some local opts. Try to remove each of the remaining longcalls. */ if (ebb_table->ebb.ends_section || ebb_table->ebb.ends_unreachable) { removed_bytes = 0; for (i = 0; i < ebb_table->action_count; i++) { int old_removed_bytes = removed_bytes; proposed_action *action = &ebb_table->actions[i]; if (action->do_action && action->action == ta_convert_longcall) { bfd_boolean bad_alignment = FALSE; removed_bytes += 3; for (j = i + 1; j < ebb_table->action_count; j++) { proposed_action *new_action = &ebb_table->actions[j]; bfd_vma offset = new_action->offset; if (new_action->align_type == EBB_REQUIRE_TGT_ALIGN) { if (!check_branch_target_aligned (ebb_table->ebb.contents, ebb_table->ebb.content_length, offset, offset - removed_bytes)) { bad_alignment = TRUE; break; } } if (new_action->align_type == EBB_REQUIRE_LOOP_ALIGN) { if (!check_loop_aligned (ebb_table->ebb.contents, ebb_table->ebb.content_length, offset, offset - removed_bytes)) { bad_alignment = TRUE; break; } } if (new_action->action == ta_narrow_insn && !new_action->do_action && ebb_table->ebb.sec->alignment_power == 2) { /* Narrow an instruction and we are done. */ new_action->do_action = TRUE; new_action->removed_bytes += 1; bad_alignment = FALSE; break; } if (new_action->action == ta_widen_insn && new_action->do_action && ebb_table->ebb.sec->alignment_power == 2) { /* Narrow an instruction and we are done. */ new_action->do_action = FALSE; new_action->removed_bytes += 1; bad_alignment = FALSE; break; } if (new_action->do_action) removed_bytes += new_action->removed_bytes; } if (!bad_alignment) { action->removed_bytes += 3; action->action = ta_remove_longcall; action->do_action = TRUE; } } removed_bytes = old_removed_bytes; if (action->do_action) removed_bytes += action->removed_bytes; } } removed_bytes = 0; for (i = 0; i < ebb_table->action_count; ++i) { proposed_action *action = &ebb_table->actions[i]; if (action->do_action) removed_bytes += action->removed_bytes; } if ((removed_bytes % (1 << ebb_table->ebb.sec->alignment_power)) != 0 && ebb->ends_unreachable) { proposed_action *action; int br; int extra_space; BFD_ASSERT (ebb_table->action_count != 0); action = &ebb_table->actions[ebb_table->action_count - 1]; BFD_ASSERT (action->action == ta_fill); BFD_ASSERT (ebb->ends_unreachable->flags & XTENSA_PROP_UNREACHABLE); extra_space = compute_fill_extra_space (ebb->ends_unreachable); br = action->removed_bytes + removed_bytes + extra_space; br = br & ((1 << ebb->sec->alignment_power ) - 1); action->removed_bytes = extra_space - br; } return TRUE; } /* The xlate_map is a sorted array of address mappings designed to answer the offset_with_removed_text() query with a binary search instead of a linear search through the section's action_list. */ typedef struct xlate_map_entry xlate_map_entry_t; typedef struct xlate_map xlate_map_t; struct xlate_map_entry { unsigned orig_address; unsigned new_address; unsigned size; }; struct xlate_map { unsigned entry_count; xlate_map_entry_t *entry; }; static int xlate_compare (const void *a_v, const void *b_v) { const xlate_map_entry_t *a = (const xlate_map_entry_t *) a_v; const xlate_map_entry_t *b = (const xlate_map_entry_t *) b_v; if (a->orig_address < b->orig_address) return -1; if (a->orig_address > (b->orig_address + b->size - 1)) return 1; return 0; } static bfd_vma xlate_offset_with_removed_text (const xlate_map_t *map, text_action_list *action_list, bfd_vma offset) { void *r; xlate_map_entry_t *e; if (map == NULL) return offset_with_removed_text (action_list, offset); if (map->entry_count == 0) return offset; r = bsearch (&offset, map->entry, map->entry_count, sizeof (xlate_map_entry_t), &xlate_compare); e = (xlate_map_entry_t *) r; BFD_ASSERT (e != NULL); if (e == NULL) return offset; return e->new_address - e->orig_address + offset; } /* Build a binary searchable offset translation map from a section's action list. */ static xlate_map_t * build_xlate_map (asection *sec, xtensa_relax_info *relax_info) { xlate_map_t *map = (xlate_map_t *) bfd_malloc (sizeof (xlate_map_t)); text_action_list *action_list = &relax_info->action_list; unsigned num_actions = 0; text_action *r; int removed; xlate_map_entry_t *current_entry; if (map == NULL) return NULL; num_actions = action_list_count (action_list); map->entry = (xlate_map_entry_t *) bfd_malloc (sizeof (xlate_map_entry_t) * (num_actions + 1)); if (map->entry == NULL) { free (map); return NULL; } map->entry_count = 0; removed = 0; current_entry = &map->entry[0]; current_entry->orig_address = 0; current_entry->new_address = 0; current_entry->size = 0; for (r = action_list->head; r != NULL; r = r->next) { unsigned orig_size = 0; switch (r->action) { case ta_none: case ta_remove_insn: case ta_convert_longcall: case ta_remove_literal: case ta_add_literal: break; case ta_remove_longcall: orig_size = 6; break; case ta_narrow_insn: orig_size = 3; break; case ta_widen_insn: orig_size = 2; break; case ta_fill: break; } current_entry->size = r->offset + orig_size - current_entry->orig_address; if (current_entry->size != 0) { current_entry++; map->entry_count++; } current_entry->orig_address = r->offset + orig_size; removed += r->removed_bytes; current_entry->new_address = r->offset + orig_size - removed; current_entry->size = 0; } current_entry->size = (bfd_get_section_limit (sec->owner, sec) - current_entry->orig_address); if (current_entry->size != 0) map->entry_count++; return map; } /* Free an offset translation map. */ static void free_xlate_map (xlate_map_t *map) { if (map && map->entry) free (map->entry); if (map) free (map); } /* Use check_section_ebb_pcrels_fit to make sure that all of the relocations in a section will fit if a proposed set of actions are performed. */ static bfd_boolean check_section_ebb_pcrels_fit (bfd *abfd, asection *sec, bfd_byte *contents, Elf_Internal_Rela *internal_relocs, const ebb_constraint *constraint, const xtensa_opcode *reloc_opcodes) { unsigned i, j; Elf_Internal_Rela *irel; xlate_map_t *xmap = NULL; bfd_boolean ok = TRUE; xtensa_relax_info *relax_info; relax_info = get_xtensa_relax_info (sec); if (relax_info && sec->reloc_count > 100) { xmap = build_xlate_map (sec, relax_info); /* NULL indicates out of memory, but the slow version can still be used. */ } for (i = 0; i < sec->reloc_count; i++) { r_reloc r_rel; bfd_vma orig_self_offset, orig_target_offset; bfd_vma self_offset, target_offset; int r_type; reloc_howto_type *howto; int self_removed_bytes, target_removed_bytes; irel = &internal_relocs[i]; r_type = ELF32_R_TYPE (irel->r_info); howto = &elf_howto_table[r_type]; /* We maintain the required invariant: PC-relative relocations that fit before linking must fit after linking. Thus we only need to deal with relocations to the same section that are PC-relative. */ if (r_type == R_XTENSA_ASM_SIMPLIFY || r_type == R_XTENSA_32_PCREL || !howto->pc_relative) continue; r_reloc_init (&r_rel, abfd, irel, contents, bfd_get_section_limit (abfd, sec)); if (r_reloc_get_section (&r_rel) != sec) continue; orig_self_offset = irel->r_offset; orig_target_offset = r_rel.target_offset; self_offset = orig_self_offset; target_offset = orig_target_offset; if (relax_info) { self_offset = xlate_offset_with_removed_text (xmap, &relax_info->action_list, orig_self_offset); target_offset = xlate_offset_with_removed_text (xmap, &relax_info->action_list, orig_target_offset); } self_removed_bytes = 0; target_removed_bytes = 0; for (j = 0; j < constraint->action_count; ++j) { proposed_action *action = &constraint->actions[j]; bfd_vma offset = action->offset; int removed_bytes = action->removed_bytes; if (offset < orig_self_offset || (offset == orig_self_offset && action->action == ta_fill && action->removed_bytes < 0)) self_removed_bytes += removed_bytes; if (offset < orig_target_offset || (offset == orig_target_offset && action->action == ta_fill && action->removed_bytes < 0)) target_removed_bytes += removed_bytes; } self_offset -= self_removed_bytes; target_offset -= target_removed_bytes; /* Try to encode it. Get the operand and check. */ if (is_alt_relocation (ELF32_R_TYPE (irel->r_info))) { /* None of the current alternate relocs are PC-relative, and only PC-relative relocs matter here. */ } else { xtensa_opcode opcode; int opnum; if (reloc_opcodes) opcode = reloc_opcodes[i]; else opcode = get_relocation_opcode (abfd, sec, contents, irel); if (opcode == XTENSA_UNDEFINED) { ok = FALSE; break; } opnum = get_relocation_opnd (opcode, ELF32_R_TYPE (irel->r_info)); if (opnum == XTENSA_UNDEFINED) { ok = FALSE; break; } if (!pcrel_reloc_fits (opcode, opnum, self_offset, target_offset)) { ok = FALSE; break; } } } if (xmap) free_xlate_map (xmap); return ok; } static bfd_boolean check_section_ebb_reduces (const ebb_constraint *constraint) { int removed = 0; unsigned i; for (i = 0; i < constraint->action_count; i++) { const proposed_action *action = &constraint->actions[i]; if (action->do_action) removed += action->removed_bytes; } if (removed < 0) return FALSE; return TRUE; } void text_action_add_proposed (text_action_list *l, const ebb_constraint *ebb_table, asection *sec) { unsigned i; for (i = 0; i < ebb_table->action_count; i++) { proposed_action *action = &ebb_table->actions[i]; if (!action->do_action) continue; switch (action->action) { case ta_remove_insn: case ta_remove_longcall: case ta_convert_longcall: case ta_narrow_insn: case ta_widen_insn: case ta_fill: case ta_remove_literal: text_action_add (l, action->action, sec, action->offset, action->removed_bytes); break; case ta_none: break; default: BFD_ASSERT (0); break; } } } int compute_fill_extra_space (property_table_entry *entry) { int fill_extra_space; if (!entry) return 0; if ((entry->flags & XTENSA_PROP_UNREACHABLE) == 0) return 0; fill_extra_space = entry->size; if ((entry->flags & XTENSA_PROP_ALIGN) != 0) { /* Fill bytes for alignment: (2**n)-1 - (addr + (2**n)-1) & (2**n -1) */ int pow = GET_XTENSA_PROP_ALIGNMENT (entry->flags); int nsm = (1 << pow) - 1; bfd_vma addr = entry->address + entry->size; bfd_vma align_fill = nsm - ((addr + nsm) & nsm); fill_extra_space += align_fill; } return fill_extra_space; } /* First relaxation pass. */ /* If the section contains relaxable literals, check each literal to see if it has the same value as another literal that has already been seen, either in the current section or a previous one. If so, add an entry to the per-section list of removed literals. The actual changes are deferred until the next pass. */ static bfd_boolean compute_removed_literals (bfd *abfd, asection *sec, struct bfd_link_info *link_info, value_map_hash_table *values) { xtensa_relax_info *relax_info; bfd_byte *contents; Elf_Internal_Rela *internal_relocs; source_reloc *src_relocs, *rel; bfd_boolean ok = TRUE; property_table_entry *prop_table = NULL; int ptblsize; int i, prev_i; bfd_boolean last_loc_is_prev = FALSE; bfd_vma last_target_offset = 0; section_cache_t target_sec_cache; bfd_size_type sec_size; init_section_cache (&target_sec_cache); /* Do nothing if it is not a relaxable literal section. */ relax_info = get_xtensa_relax_info (sec); BFD_ASSERT (relax_info); if (!relax_info->is_relaxable_literal_section) return ok; internal_relocs = retrieve_internal_relocs (abfd, sec, link_info->keep_memory); sec_size = bfd_get_section_limit (abfd, sec); contents = retrieve_contents (abfd, sec, link_info->keep_memory); if (contents == NULL && sec_size != 0) { ok = FALSE; goto error_return; } /* Sort the source_relocs by target offset. */ src_relocs = relax_info->src_relocs; qsort (src_relocs, relax_info->src_count, sizeof (source_reloc), source_reloc_compare); qsort (internal_relocs, sec->reloc_count, sizeof (Elf_Internal_Rela), internal_reloc_compare); ptblsize = xtensa_read_table_entries (abfd, sec, &prop_table, XTENSA_PROP_SEC_NAME, FALSE); if (ptblsize < 0) { ok = FALSE; goto error_return; } prev_i = -1; for (i = 0; i < relax_info->src_count; i++) { Elf_Internal_Rela *irel = NULL; rel = &src_relocs[i]; if (get_l32r_opcode () != rel->opcode) continue; irel = get_irel_at_offset (sec, internal_relocs, rel->r_rel.target_offset); /* If the relocation on this is not a simple R_XTENSA_32 or R_XTENSA_PLT then do not consider it. This may happen when the difference of two symbols is used in a literal. */ if (irel && (ELF32_R_TYPE (irel->r_info) != R_XTENSA_32 && ELF32_R_TYPE (irel->r_info) != R_XTENSA_PLT)) continue; /* If the target_offset for this relocation is the same as the previous relocation, then we've already considered whether the literal can be coalesced. Skip to the next one.... */ if (i != 0 && prev_i != -1 && src_relocs[i-1].r_rel.target_offset == rel->r_rel.target_offset) continue; prev_i = i; if (last_loc_is_prev && last_target_offset + 4 != rel->r_rel.target_offset) last_loc_is_prev = FALSE; /* Check if the relocation was from an L32R that is being removed because a CALLX was converted to a direct CALL, and check if there are no other relocations to the literal. */ if (is_removable_literal (rel, i, src_relocs, relax_info->src_count, sec, prop_table, ptblsize)) { if (!remove_dead_literal (abfd, sec, link_info, internal_relocs, irel, rel, prop_table, ptblsize)) { ok = FALSE; goto error_return; } last_target_offset = rel->r_rel.target_offset; continue; } if (!identify_literal_placement (abfd, sec, contents, link_info, values, &last_loc_is_prev, irel, relax_info->src_count - i, rel, prop_table, ptblsize, &target_sec_cache, rel->is_abs_literal)) { ok = FALSE; goto error_return; } last_target_offset = rel->r_rel.target_offset; } #if DEBUG print_removed_literals (stderr, &relax_info->removed_list); print_action_list (stderr, &relax_info->action_list); #endif /* DEBUG */ error_return: if (prop_table) free (prop_table); clear_section_cache (&target_sec_cache); release_contents (sec, contents); release_internal_relocs (sec, internal_relocs); return ok; } static Elf_Internal_Rela * get_irel_at_offset (asection *sec, Elf_Internal_Rela *internal_relocs, bfd_vma offset) { unsigned i; Elf_Internal_Rela *irel; unsigned r_type; Elf_Internal_Rela key; if (!internal_relocs) return NULL; key.r_offset = offset; irel = bsearch (&key, internal_relocs, sec->reloc_count, sizeof (Elf_Internal_Rela), internal_reloc_matches); if (!irel) return NULL; /* bsearch does not guarantee which will be returned if there are multiple matches. We need the first that is not an alignment. */ i = irel - internal_relocs; while (i > 0) { if (internal_relocs[i-1].r_offset != offset) break; i--; } for ( ; i < sec->reloc_count; i++) { irel = &internal_relocs[i]; r_type = ELF32_R_TYPE (irel->r_info); if (irel->r_offset == offset && r_type != R_XTENSA_NONE) return irel; } return NULL; } bfd_boolean is_removable_literal (const source_reloc *rel, int i, const source_reloc *src_relocs, int src_count, asection *sec, property_table_entry *prop_table, int ptblsize) { const source_reloc *curr_rel; property_table_entry *entry; if (!rel->is_null) return FALSE; entry = elf_xtensa_find_property_entry (prop_table, ptblsize, sec->vma + rel->r_rel.target_offset); if (entry && (entry->flags & XTENSA_PROP_NO_TRANSFORM)) return FALSE; for (++i; i < src_count; ++i) { curr_rel = &src_relocs[i]; /* If all others have the same target offset.... */ if (curr_rel->r_rel.target_offset != rel->r_rel.target_offset) return TRUE; if (!curr_rel->is_null && !xtensa_is_property_section (curr_rel->source_sec) && !(curr_rel->source_sec->flags & SEC_DEBUGGING)) return FALSE; } return TRUE; } bfd_boolean remove_dead_literal (bfd *abfd, asection *sec, struct bfd_link_info *link_info, Elf_Internal_Rela *internal_relocs, Elf_Internal_Rela *irel, source_reloc *rel, property_table_entry *prop_table, int ptblsize) { property_table_entry *entry; xtensa_relax_info *relax_info; relax_info = get_xtensa_relax_info (sec); if (!relax_info) return FALSE; entry = elf_xtensa_find_property_entry (prop_table, ptblsize, sec->vma + rel->r_rel.target_offset); /* Mark the unused literal so that it will be removed. */ add_removed_literal (&relax_info->removed_list, &rel->r_rel, NULL); text_action_add (&relax_info->action_list, ta_remove_literal, sec, rel->r_rel.target_offset, 4); /* If the section is 4-byte aligned, do not add fill. */ if (sec->alignment_power > 2) { int fill_extra_space; bfd_vma entry_sec_offset; text_action *fa; property_table_entry *the_add_entry; int removed_diff; if (entry) entry_sec_offset = entry->address - sec->vma + entry->size; else entry_sec_offset = rel->r_rel.target_offset + 4; /* If the literal range is at the end of the section, do not add fill. */ the_add_entry = elf_xtensa_find_property_entry (prop_table, ptblsize, entry_sec_offset); fill_extra_space = compute_fill_extra_space (the_add_entry); fa = find_fill_action (&relax_info->action_list, sec, entry_sec_offset); removed_diff = compute_removed_action_diff (fa, sec, entry_sec_offset, -4, fill_extra_space); if (fa) adjust_fill_action (fa, removed_diff); else text_action_add (&relax_info->action_list, ta_fill, sec, entry_sec_offset, removed_diff); } /* Zero out the relocation on this literal location. */ if (irel) { if (elf_hash_table (link_info)->dynamic_sections_created) shrink_dynamic_reloc_sections (link_info, abfd, sec, irel); irel->r_info = ELF32_R_INFO (0, R_XTENSA_NONE); pin_internal_relocs (sec, internal_relocs); } /* Do not modify "last_loc_is_prev". */ return TRUE; } bfd_boolean identify_literal_placement (bfd *abfd, asection *sec, bfd_byte *contents, struct bfd_link_info *link_info, value_map_hash_table *values, bfd_boolean *last_loc_is_prev_p, Elf_Internal_Rela *irel, int remaining_src_rels, source_reloc *rel, property_table_entry *prop_table, int ptblsize, section_cache_t *target_sec_cache, bfd_boolean is_abs_literal) { literal_value val; value_map *val_map; xtensa_relax_info *relax_info; bfd_boolean literal_placed = FALSE; r_reloc r_rel; unsigned long value; bfd_boolean final_static_link; bfd_size_type sec_size; relax_info = get_xtensa_relax_info (sec); if (!relax_info) return FALSE; sec_size = bfd_get_section_limit (abfd, sec); final_static_link = (!link_info->relocatable && !elf_hash_table (link_info)->dynamic_sections_created); /* The placement algorithm first checks to see if the literal is already in the value map. If so and the value map is reachable from all uses, then the literal is moved to that location. If not, then we identify the last location where a fresh literal was placed. If the literal can be safely moved there, then we do so. If not, then we assume that the literal is not to move and leave the literal where it is, marking it as the last literal location. */ /* Find the literal value. */ value = 0; r_reloc_init (&r_rel, abfd, irel, contents, sec_size); if (!irel) { BFD_ASSERT (rel->r_rel.target_offset < sec_size); value = bfd_get_32 (abfd, contents + rel->r_rel.target_offset); } init_literal_value (&val, &r_rel, value, is_abs_literal); /* Check if we've seen another literal with the same value that is in the same output section. */ val_map = value_map_get_cached_value (values, &val, final_static_link); if (val_map && (r_reloc_get_section (&val_map->loc)->output_section == sec->output_section) && relocations_reach (rel, remaining_src_rels, &val_map->loc) && coalesce_shared_literal (sec, rel, prop_table, ptblsize, val_map)) { /* No change to last_loc_is_prev. */ literal_placed = TRUE; } /* For relocatable links, do not try to move literals. To do it correctly might increase the number of relocations in an input section making the default relocatable linking fail. */ if (!link_info->relocatable && !literal_placed && values->has_last_loc && !(*last_loc_is_prev_p)) { asection *target_sec = r_reloc_get_section (&values->last_loc); if (target_sec && target_sec->output_section == sec->output_section) { /* Increment the virtual offset. */ r_reloc try_loc = values->last_loc; try_loc.virtual_offset += 4; /* There is a last loc that was in the same output section. */ if (relocations_reach (rel, remaining_src_rels, &try_loc) && move_shared_literal (sec, link_info, rel, prop_table, ptblsize, &try_loc, &val, target_sec_cache)) { values->last_loc.virtual_offset += 4; literal_placed = TRUE; if (!val_map) val_map = add_value_map (values, &val, &try_loc, final_static_link); else val_map->loc = try_loc; } } } if (!literal_placed) { /* Nothing worked, leave the literal alone but update the last loc. */ values->has_last_loc = TRUE; values->last_loc = rel->r_rel; if (!val_map) val_map = add_value_map (values, &val, &rel->r_rel, final_static_link); else val_map->loc = rel->r_rel; *last_loc_is_prev_p = TRUE; } return TRUE; } /* Check if the original relocations (presumably on L32R instructions) identified by reloc[0..N] can be changed to reference the literal identified by r_rel. If r_rel is out of range for any of the original relocations, then we don't want to coalesce the original literal with the one at r_rel. We only check reloc[0..N], where the offsets are all the same as for reloc[0] (i.e., they're all referencing the same literal) and where N is also bounded by the number of remaining entries in the "reloc" array. The "reloc" array is sorted by target offset so we know all the entries for the same literal will be contiguous. */ static bfd_boolean relocations_reach (source_reloc *reloc, int remaining_relocs, const r_reloc *r_rel) { bfd_vma from_offset, source_address, dest_address; asection *sec; int i; if (!r_reloc_is_defined (r_rel)) return FALSE; sec = r_reloc_get_section (r_rel); from_offset = reloc[0].r_rel.target_offset; for (i = 0; i < remaining_relocs; i++) { if (reloc[i].r_rel.target_offset != from_offset) break; /* Ignore relocations that have been removed. */ if (reloc[i].is_null) continue; /* The original and new output section for these must be the same in order to coalesce. */ if (r_reloc_get_section (&reloc[i].r_rel)->output_section != sec->output_section) return FALSE; /* Absolute literals in the same output section can always be combined. */ if (reloc[i].is_abs_literal) continue; /* A literal with no PC-relative relocations can be moved anywhere. */ if (reloc[i].opnd != -1) { /* Otherwise, check to see that it fits. */ source_address = (reloc[i].source_sec->output_section->vma + reloc[i].source_sec->output_offset + reloc[i].r_rel.rela.r_offset); dest_address = (sec->output_section->vma + sec->output_offset + r_rel->target_offset); if (!pcrel_reloc_fits (reloc[i].opcode, reloc[i].opnd, source_address, dest_address)) return FALSE; } } return TRUE; } /* Move a literal to another literal location because it is the same as the other literal value. */ static bfd_boolean coalesce_shared_literal (asection *sec, source_reloc *rel, property_table_entry *prop_table, int ptblsize, value_map *val_map) { property_table_entry *entry; text_action *fa; property_table_entry *the_add_entry; int removed_diff; xtensa_relax_info *relax_info; relax_info = get_xtensa_relax_info (sec); if (!relax_info) return FALSE; entry = elf_xtensa_find_property_entry (prop_table, ptblsize, sec->vma + rel->r_rel.target_offset); if (entry && (entry->flags & XTENSA_PROP_NO_TRANSFORM)) return TRUE; /* Mark that the literal will be coalesced. */ add_removed_literal (&relax_info->removed_list, &rel->r_rel, &val_map->loc); text_action_add (&relax_info->action_list, ta_remove_literal, sec, rel->r_rel.target_offset, 4); /* If the section is 4-byte aligned, do not add fill. */ if (sec->alignment_power > 2) { int fill_extra_space; bfd_vma entry_sec_offset; if (entry) entry_sec_offset = entry->address - sec->vma + entry->size; else entry_sec_offset = rel->r_rel.target_offset + 4; /* If the literal range is at the end of the section, do not add fill. */ fill_extra_space = 0; the_add_entry = elf_xtensa_find_property_entry (prop_table, ptblsize, entry_sec_offset); if (the_add_entry && (the_add_entry->flags & XTENSA_PROP_UNREACHABLE)) fill_extra_space = the_add_entry->size; fa = find_fill_action (&relax_info->action_list, sec, entry_sec_offset); removed_diff = compute_removed_action_diff (fa, sec, entry_sec_offset, -4, fill_extra_space); if (fa) adjust_fill_action (fa, removed_diff); else text_action_add (&relax_info->action_list, ta_fill, sec, entry_sec_offset, removed_diff); } return TRUE; } /* Move a literal to another location. This may actually increase the total amount of space used because of alignments so we need to do this carefully. Also, it may make a branch go out of range. */ static bfd_boolean move_shared_literal (asection *sec, struct bfd_link_info *link_info, source_reloc *rel, property_table_entry *prop_table, int ptblsize, const r_reloc *target_loc, const literal_value *lit_value, section_cache_t *target_sec_cache) { property_table_entry *the_add_entry, *src_entry, *target_entry = NULL; text_action *fa, *target_fa; int removed_diff; xtensa_relax_info *relax_info, *target_relax_info; asection *target_sec; ebb_t *ebb; ebb_constraint ebb_table; bfd_boolean relocs_fit; /* If this routine always returns FALSE, the literals that cannot be coalesced will not be moved. */ if (elf32xtensa_no_literal_movement) return FALSE; relax_info = get_xtensa_relax_info (sec); if (!relax_info) return FALSE; target_sec = r_reloc_get_section (target_loc); target_relax_info = get_xtensa_relax_info (target_sec); /* Literals to undefined sections may not be moved because they must report an error. */ if (bfd_is_und_section (target_sec)) return FALSE; src_entry = elf_xtensa_find_property_entry (prop_table, ptblsize, sec->vma + rel->r_rel.target_offset); if (!section_cache_section (target_sec_cache, target_sec, link_info)) return FALSE; target_entry = elf_xtensa_find_property_entry (target_sec_cache->ptbl, target_sec_cache->pte_count, target_sec->vma + target_loc->target_offset); if (!target_entry) return FALSE; /* Make sure that we have not broken any branches. */ relocs_fit = FALSE; init_ebb_constraint (&ebb_table); ebb = &ebb_table.ebb; init_ebb (ebb, target_sec_cache->sec, target_sec_cache->contents, target_sec_cache->content_length, target_sec_cache->ptbl, target_sec_cache->pte_count, target_sec_cache->relocs, target_sec_cache->reloc_count); /* Propose to add 4 bytes + worst-case alignment size increase to destination. */ ebb_propose_action (&ebb_table, EBB_NO_ALIGN, 0, ta_fill, target_loc->target_offset, -4 - (1 << target_sec->alignment_power), TRUE); /* Check all of the PC-relative relocations to make sure they still fit. */ relocs_fit = check_section_ebb_pcrels_fit (target_sec->owner, target_sec, target_sec_cache->contents, target_sec_cache->relocs, &ebb_table, NULL); if (!relocs_fit) return FALSE; text_action_add_literal (&target_relax_info->action_list, ta_add_literal, target_loc, lit_value, -4); if (target_sec->alignment_power > 2 && target_entry != src_entry) { /* May need to add or remove some fill to maintain alignment. */ int fill_extra_space; bfd_vma entry_sec_offset; entry_sec_offset = target_entry->address - target_sec->vma + target_entry->size; /* If the literal range is at the end of the section, do not add fill. */ fill_extra_space = 0; the_add_entry = elf_xtensa_find_property_entry (target_sec_cache->ptbl, target_sec_cache->pte_count, entry_sec_offset); if (the_add_entry && (the_add_entry->flags & XTENSA_PROP_UNREACHABLE)) fill_extra_space = the_add_entry->size; target_fa = find_fill_action (&target_relax_info->action_list, target_sec, entry_sec_offset); removed_diff = compute_removed_action_diff (target_fa, target_sec, entry_sec_offset, 4, fill_extra_space); if (target_fa) adjust_fill_action (target_fa, removed_diff); else text_action_add (&target_relax_info->action_list, ta_fill, target_sec, entry_sec_offset, removed_diff); } /* Mark that the literal will be moved to the new location. */ add_removed_literal (&relax_info->removed_list, &rel->r_rel, target_loc); /* Remove the literal. */ text_action_add (&relax_info->action_list, ta_remove_literal, sec, rel->r_rel.target_offset, 4); /* If the section is 4-byte aligned, do not add fill. */ if (sec->alignment_power > 2 && target_entry != src_entry) { int fill_extra_space; bfd_vma entry_sec_offset; if (src_entry) entry_sec_offset = src_entry->address - sec->vma + src_entry->size; else entry_sec_offset = rel->r_rel.target_offset+4; /* If the literal range is at the end of the section, do not add fill. */ fill_extra_space = 0; the_add_entry = elf_xtensa_find_property_entry (prop_table, ptblsize, entry_sec_offset); if (the_add_entry && (the_add_entry->flags & XTENSA_PROP_UNREACHABLE)) fill_extra_space = the_add_entry->size; fa = find_fill_action (&relax_info->action_list, sec, entry_sec_offset); removed_diff = compute_removed_action_diff (fa, sec, entry_sec_offset, -4, fill_extra_space); if (fa) adjust_fill_action (fa, removed_diff); else text_action_add (&relax_info->action_list, ta_fill, sec, entry_sec_offset, removed_diff); } return TRUE; } /* Second relaxation pass. */ /* Modify all of the relocations to point to the right spot, and if this is a relaxable section, delete the unwanted literals and fix the section size. */ bfd_boolean relax_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info) { Elf_Internal_Rela *internal_relocs; xtensa_relax_info *relax_info; bfd_byte *contents; bfd_boolean ok = TRUE; unsigned i; bfd_boolean rv = FALSE; bfd_boolean virtual_action; bfd_size_type sec_size; sec_size = bfd_get_section_limit (abfd, sec); relax_info = get_xtensa_relax_info (sec); BFD_ASSERT (relax_info); /* First translate any of the fixes that have been added already. */ translate_section_fixes (sec); /* Handle property sections (e.g., literal tables) specially. */ if (xtensa_is_property_section (sec)) { BFD_ASSERT (!relax_info->is_relaxable_literal_section); return relax_property_section (abfd, sec, link_info); } internal_relocs = retrieve_internal_relocs (abfd, sec, link_info->keep_memory); if (!internal_relocs && !relax_info->action_list.head) return TRUE; contents = retrieve_contents (abfd, sec, link_info->keep_memory); if (contents == NULL && sec_size != 0) { ok = FALSE; goto error_return; } if (internal_relocs) { for (i = 0; i < sec->reloc_count; i++) { Elf_Internal_Rela *irel; xtensa_relax_info *target_relax_info; bfd_vma source_offset, old_source_offset; r_reloc r_rel; unsigned r_type; asection *target_sec; /* Locally change the source address. Translate the target to the new target address. If it points to this section and has been removed, NULLify it. Write it back. */ irel = &internal_relocs[i]; source_offset = irel->r_offset; old_source_offset = source_offset; r_type = ELF32_R_TYPE (irel->r_info); r_reloc_init (&r_rel, abfd, irel, contents, bfd_get_section_limit (abfd, sec)); /* If this section could have changed then we may need to change the relocation's offset. */ if (relax_info->is_relaxable_literal_section || relax_info->is_relaxable_asm_section) { pin_internal_relocs (sec, internal_relocs); if (r_type != R_XTENSA_NONE && find_removed_literal (&relax_info->removed_list, irel->r_offset)) { /* Remove this relocation. */ if (elf_hash_table (link_info)->dynamic_sections_created) shrink_dynamic_reloc_sections (link_info, abfd, sec, irel); irel->r_info = ELF32_R_INFO (0, R_XTENSA_NONE); irel->r_offset = offset_with_removed_text (&relax_info->action_list, irel->r_offset); continue; } if (r_type == R_XTENSA_ASM_SIMPLIFY) { text_action *action = find_insn_action (&relax_info->action_list, irel->r_offset); if (action && (action->action == ta_convert_longcall || action->action == ta_remove_longcall)) { bfd_reloc_status_type retval; char *error_message = NULL; retval = contract_asm_expansion (contents, sec_size, irel, &error_message); if (retval != bfd_reloc_ok) { (*link_info->callbacks->reloc_dangerous) (link_info, error_message, abfd, sec, irel->r_offset); goto error_return; } /* Update the action so that the code that moves the contents will do the right thing. */ if (action->action == ta_remove_longcall) action->action = ta_remove_insn; else action->action = ta_none; /* Refresh the info in the r_rel. */ r_reloc_init (&r_rel, abfd, irel, contents, sec_size); r_type = ELF32_R_TYPE (irel->r_info); } } source_offset = offset_with_removed_text (&relax_info->action_list, irel->r_offset); irel->r_offset = source_offset; } /* If the target section could have changed then we may need to change the relocation's target offset. */ target_sec = r_reloc_get_section (&r_rel); /* For a reference to a discarded section from a DWARF section, i.e., where action_discarded is PRETEND, the symbol will eventually be modified to refer to the kept section (at least if the kept and discarded sections are the same size). Anticipate that here and adjust things accordingly. */ if (! elf_xtensa_ignore_discarded_relocs (sec) && elf_xtensa_action_discarded (sec) == PRETEND && sec->sec_info_type != ELF_INFO_TYPE_STABS && target_sec != NULL && elf_discarded_section (target_sec)) { /* It would be natural to call _bfd_elf_check_kept_section here, but it's not exported from elflink.c. It's also a fairly expensive check. Adjusting the relocations to the discarded section is fairly harmless; it will only adjust some addends and difference values. If it turns out that _bfd_elf_check_kept_section fails later, it won't matter, so just compare the section names to find the right group member. */ asection *kept = target_sec->kept_section; if (kept != NULL) { if ((kept->flags & SEC_GROUP) != 0) { asection *first = elf_next_in_group (kept); asection *s = first; kept = NULL; while (s != NULL) { if (strcmp (s->name, target_sec->name) == 0) { kept = s; break; } s = elf_next_in_group (s); if (s == first) break; } } } if (kept != NULL && ((target_sec->rawsize != 0 ? target_sec->rawsize : target_sec->size) == (kept->rawsize != 0 ? kept->rawsize : kept->size))) target_sec = kept; } target_relax_info = get_xtensa_relax_info (target_sec); if (target_relax_info && (target_relax_info->is_relaxable_literal_section || target_relax_info->is_relaxable_asm_section)) { r_reloc new_reloc; target_sec = translate_reloc (&r_rel, &new_reloc, target_sec); if (r_type == R_XTENSA_DIFF8 || r_type == R_XTENSA_DIFF16 || r_type == R_XTENSA_DIFF32) { bfd_vma diff_value = 0, new_end_offset, diff_mask = 0; if (bfd_get_section_limit (abfd, sec) < old_source_offset) { (*link_info->callbacks->reloc_dangerous) (link_info, _("invalid relocation address"), abfd, sec, old_source_offset); goto error_return; } switch (r_type) { case R_XTENSA_DIFF8: diff_value = bfd_get_8 (abfd, &contents[old_source_offset]); break; case R_XTENSA_DIFF16: diff_value = bfd_get_16 (abfd, &contents[old_source_offset]); break; case R_XTENSA_DIFF32: diff_value = bfd_get_32 (abfd, &contents[old_source_offset]); break; } new_end_offset = offset_with_removed_text (&target_relax_info->action_list, r_rel.target_offset + diff_value); diff_value = new_end_offset - new_reloc.target_offset; switch (r_type) { case R_XTENSA_DIFF8: diff_mask = 0xff; bfd_put_8 (abfd, diff_value, &contents[old_source_offset]); break; case R_XTENSA_DIFF16: diff_mask = 0xffff; bfd_put_16 (abfd, diff_value, &contents[old_source_offset]); break; case R_XTENSA_DIFF32: diff_mask = 0xffffffff; bfd_put_32 (abfd, diff_value, &contents[old_source_offset]); break; } /* Check for overflow. */ if ((diff_value & ~diff_mask) != 0) { (*link_info->callbacks->reloc_dangerous) (link_info, _("overflow after relaxation"), abfd, sec, old_source_offset); goto error_return; } pin_contents (sec, contents); } /* If the relocation still references a section in the same input file, modify the relocation directly instead of adding a "fix" record. */ if (target_sec->owner == abfd) { unsigned r_symndx = ELF32_R_SYM (new_reloc.rela.r_info); irel->r_info = ELF32_R_INFO (r_symndx, r_type); irel->r_addend = new_reloc.rela.r_addend; pin_internal_relocs (sec, internal_relocs); } else { bfd_vma addend_displacement; reloc_bfd_fix *fix; addend_displacement = new_reloc.target_offset + new_reloc.virtual_offset; fix = reloc_bfd_fix_init (sec, source_offset, r_type, target_sec, addend_displacement, TRUE); add_fix (sec, fix); } } } } if ((relax_info->is_relaxable_literal_section || relax_info->is_relaxable_asm_section) && relax_info->action_list.head) { /* Walk through the planned actions and build up a table of move, copy and fill records. Use the move, copy and fill records to perform the actions once. */ int removed = 0; bfd_size_type final_size, copy_size, orig_insn_size; bfd_byte *scratch = NULL; bfd_byte *dup_contents = NULL; bfd_size_type orig_size = sec->size; bfd_vma orig_dot = 0; bfd_vma orig_dot_copied = 0; /* Byte copied already from orig dot in physical memory. */ bfd_vma orig_dot_vo = 0; /* Virtual offset from orig_dot. */ bfd_vma dup_dot = 0; text_action *action = relax_info->action_list.head; final_size = sec->size; for (action = relax_info->action_list.head; action; action = action->next) { final_size -= action->removed_bytes; } scratch = (bfd_byte *) bfd_zmalloc (final_size); dup_contents = (bfd_byte *) bfd_zmalloc (final_size); /* The dot is the current fill location. */ #if DEBUG print_action_list (stderr, &relax_info->action_list); #endif for (action = relax_info->action_list.head; action; action = action->next) { virtual_action = FALSE; if (action->offset > orig_dot) { orig_dot += orig_dot_copied; orig_dot_copied = 0; orig_dot_vo = 0; /* Out of the virtual world. */ } if (action->offset > orig_dot) { copy_size = action->offset - orig_dot; memmove (&dup_contents[dup_dot], &contents[orig_dot], copy_size); orig_dot += copy_size; dup_dot += copy_size; BFD_ASSERT (action->offset == orig_dot); } else if (action->offset < orig_dot) { if (action->action == ta_fill && action->offset - action->removed_bytes == orig_dot) { /* This is OK because the fill only effects the dup_dot. */ } else if (action->action == ta_add_literal) { /* TBD. Might need to handle this. */ } } if (action->offset == orig_dot) { if (action->virtual_offset > orig_dot_vo) { if (orig_dot_vo == 0) { /* Need to copy virtual_offset bytes. Probably four. */ copy_size = action->virtual_offset - orig_dot_vo; memmove (&dup_contents[dup_dot], &contents[orig_dot], copy_size); orig_dot_copied = copy_size; dup_dot += copy_size; } virtual_action = TRUE; } else BFD_ASSERT (action->virtual_offset <= orig_dot_vo); } switch (action->action) { case ta_remove_literal: case ta_remove_insn: BFD_ASSERT (action->removed_bytes >= 0); orig_dot += action->removed_bytes; break; case ta_narrow_insn: orig_insn_size = 3; copy_size = 2; memmove (scratch, &contents[orig_dot], orig_insn_size); BFD_ASSERT (action->removed_bytes == 1); rv = narrow_instruction (scratch, final_size, 0); BFD_ASSERT (rv); memmove (&dup_contents[dup_dot], scratch, copy_size); orig_dot += orig_insn_size; dup_dot += copy_size; break; case ta_fill: if (action->removed_bytes >= 0) orig_dot += action->removed_bytes; else { /* Already zeroed in dup_contents. Just bump the counters. */ dup_dot += (-action->removed_bytes); } break; case ta_none: BFD_ASSERT (action->removed_bytes == 0); break; case ta_convert_longcall: case ta_remove_longcall: /* These will be removed or converted before we get here. */ BFD_ASSERT (0); break; case ta_widen_insn: orig_insn_size = 2; copy_size = 3; memmove (scratch, &contents[orig_dot], orig_insn_size); BFD_ASSERT (action->removed_bytes == -1); rv = widen_instruction (scratch, final_size, 0); BFD_ASSERT (rv); memmove (&dup_contents[dup_dot], scratch, copy_size); orig_dot += orig_insn_size; dup_dot += copy_size; break; case ta_add_literal: orig_insn_size = 0; copy_size = 4; BFD_ASSERT (action->removed_bytes == -4); /* TBD -- place the literal value here and insert into the table. */ memset (&dup_contents[dup_dot], 0, 4); pin_internal_relocs (sec, internal_relocs); pin_contents (sec, contents); if (!move_literal (abfd, link_info, sec, dup_dot, dup_contents, relax_info, &internal_relocs, &action->value)) goto error_return; if (virtual_action) orig_dot_vo += copy_size; orig_dot += orig_insn_size; dup_dot += copy_size; break; default: /* Not implemented yet. */ BFD_ASSERT (0); break; } removed += action->removed_bytes; BFD_ASSERT (dup_dot <= final_size); BFD_ASSERT (orig_dot <= orig_size); } orig_dot += orig_dot_copied; orig_dot_copied = 0; if (orig_dot != orig_size) { copy_size = orig_size - orig_dot; BFD_ASSERT (orig_size > orig_dot); BFD_ASSERT (dup_dot + copy_size == final_size); memmove (&dup_contents[dup_dot], &contents[orig_dot], copy_size); orig_dot += copy_size; dup_dot += copy_size; } BFD_ASSERT (orig_size == orig_dot); BFD_ASSERT (final_size == dup_dot); /* Move the dup_contents back. */ if (final_size > orig_size) { /* Contents need to be reallocated. Swap the dup_contents into contents. */ sec->contents = dup_contents; free (contents); contents = dup_contents; pin_contents (sec, contents); } else { BFD_ASSERT (final_size <= orig_size); memset (contents, 0, orig_size); memcpy (contents, dup_contents, final_size); free (dup_contents); } free (scratch); pin_contents (sec, contents); if (sec->rawsize == 0) sec->rawsize = sec->size; sec->size = final_size; } error_return: release_internal_relocs (sec, internal_relocs); release_contents (sec, contents); return ok; } static bfd_boolean translate_section_fixes (asection *sec) { xtensa_relax_info *relax_info; reloc_bfd_fix *r; relax_info = get_xtensa_relax_info (sec); if (!relax_info) return TRUE; for (r = relax_info->fix_list; r != NULL; r = r->next) if (!translate_reloc_bfd_fix (r)) return FALSE; return TRUE; } /* Translate a fix given the mapping in the relax info for the target section. If it has already been translated, no work is required. */ static bfd_boolean translate_reloc_bfd_fix (reloc_bfd_fix *fix) { reloc_bfd_fix new_fix; asection *sec; xtensa_relax_info *relax_info; removed_literal *removed; bfd_vma new_offset, target_offset; if (fix->translated) return TRUE; sec = fix->target_sec; target_offset = fix->target_offset; relax_info = get_xtensa_relax_info (sec); if (!relax_info) { fix->translated = TRUE; return TRUE; } new_fix = *fix; /* The fix does not need to be translated if the section cannot change. */ if (!relax_info->is_relaxable_literal_section && !relax_info->is_relaxable_asm_section) { fix->translated = TRUE; return TRUE; } /* If the literal has been moved and this relocation was on an opcode, then the relocation should move to the new literal location. Otherwise, the relocation should move within the section. */ removed = FALSE; if (is_operand_relocation (fix->src_type)) { /* Check if the original relocation is against a literal being removed. */ removed = find_removed_literal (&relax_info->removed_list, target_offset); } if (removed) { asection *new_sec; /* The fact that there is still a relocation to this literal indicates that the literal is being coalesced, not simply removed. */ BFD_ASSERT (removed->to.abfd != NULL); /* This was moved to some other address (possibly another section). */ new_sec = r_reloc_get_section (&removed->to); if (new_sec != sec) { sec = new_sec; relax_info = get_xtensa_relax_info (sec); if (!relax_info || (!relax_info->is_relaxable_literal_section && !relax_info->is_relaxable_asm_section)) { target_offset = removed->to.target_offset; new_fix.target_sec = new_sec; new_fix.target_offset = target_offset; new_fix.translated = TRUE; *fix = new_fix; return TRUE; } } target_offset = removed->to.target_offset; new_fix.target_sec = new_sec; } /* The target address may have been moved within its section. */ new_offset = offset_with_removed_text (&relax_info->action_list, target_offset); new_fix.target_offset = new_offset; new_fix.target_offset = new_offset; new_fix.translated = TRUE; *fix = new_fix; return TRUE; } /* Fix up a relocation to take account of removed literals. */ static asection * translate_reloc (const r_reloc *orig_rel, r_reloc *new_rel, asection *sec) { xtensa_relax_info *relax_info; removed_literal *removed; bfd_vma target_offset, base_offset; text_action *act; *new_rel = *orig_rel; if (!r_reloc_is_defined (orig_rel)) return sec ; relax_info = get_xtensa_relax_info (sec); BFD_ASSERT (relax_info && (relax_info->is_relaxable_literal_section || relax_info->is_relaxable_asm_section)); target_offset = orig_rel->target_offset; removed = FALSE; if (is_operand_relocation (ELF32_R_TYPE (orig_rel->rela.r_info))) { /* Check if the original relocation is against a literal being removed. */ removed = find_removed_literal (&relax_info->removed_list, target_offset); } if (removed && removed->to.abfd) { asection *new_sec; /* The fact that there is still a relocation to this literal indicates that the literal is being coalesced, not simply removed. */ BFD_ASSERT (removed->to.abfd != NULL); /* This was moved to some other address (possibly in another section). */ *new_rel = removed->to; new_sec = r_reloc_get_section (new_rel); if (new_sec != sec) { sec = new_sec; relax_info = get_xtensa_relax_info (sec); if (!relax_info || (!relax_info->is_relaxable_literal_section && !relax_info->is_relaxable_asm_section)) return sec; } target_offset = new_rel->target_offset; } /* Find the base offset of the reloc symbol, excluding any addend from the reloc or from the section contents (for a partial_inplace reloc). Then find the adjusted values of the offsets due to relaxation. The base offset is needed to determine the change to the reloc's addend; the reloc addend should not be adjusted due to relaxations located before the base offset. */ base_offset = r_reloc_get_target_offset (new_rel) - new_rel->rela.r_addend; act = relax_info->action_list.head; if (base_offset <= target_offset) { int base_removed = removed_by_actions (&act, base_offset, FALSE); int addend_removed = removed_by_actions (&act, target_offset, FALSE); new_rel->target_offset = target_offset - base_removed - addend_removed; new_rel->rela.r_addend -= addend_removed; } else { /* Handle a negative addend. The base offset comes first. */ int tgt_removed = removed_by_actions (&act, target_offset, FALSE); int addend_removed = removed_by_actions (&act, base_offset, FALSE); new_rel->target_offset = target_offset - tgt_removed; new_rel->rela.r_addend += addend_removed; } return sec; } /* For dynamic links, there may be a dynamic relocation for each literal. The number of dynamic relocations must be computed in size_dynamic_sections, which occurs before relaxation. When a literal is removed, this function checks if there is a corresponding dynamic relocation and shrinks the size of the appropriate dynamic relocation section accordingly. At this point, the contents of the dynamic relocation sections have not yet been filled in, so there's nothing else that needs to be done. */ static void shrink_dynamic_reloc_sections (struct bfd_link_info *info, bfd *abfd, asection *input_section, Elf_Internal_Rela *rel) { struct elf_xtensa_link_hash_table *htab; Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes; unsigned long r_symndx; int r_type; struct elf_link_hash_entry *h; bfd_boolean dynamic_symbol; htab = elf_xtensa_hash_table (info); if (htab == NULL) return; symtab_hdr = &elf_tdata (abfd)->symtab_hdr; sym_hashes = elf_sym_hashes (abfd); r_type = ELF32_R_TYPE (rel->r_info); r_symndx = ELF32_R_SYM (rel->r_info); if (r_symndx < symtab_hdr->sh_info) h = NULL; else h = sym_hashes[r_symndx - symtab_hdr->sh_info]; dynamic_symbol = elf_xtensa_dynamic_symbol_p (h, info); if ((r_type == R_XTENSA_32 || r_type == R_XTENSA_PLT) && (input_section->flags & SEC_ALLOC) != 0 && (dynamic_symbol || info->shared)) { asection *srel; bfd_boolean is_plt = FALSE; if (dynamic_symbol && r_type == R_XTENSA_PLT) { srel = htab->srelplt; is_plt = TRUE; } else srel = htab->srelgot; /* Reduce size of the .rela.* section by one reloc. */ BFD_ASSERT (srel != NULL); BFD_ASSERT (srel->size >= sizeof (Elf32_External_Rela)); srel->size -= sizeof (Elf32_External_Rela); if (is_plt) { asection *splt, *sgotplt, *srelgot; int reloc_index, chunk; /* Find the PLT reloc index of the entry being removed. This is computed from the size of ".rela.plt". It is needed to figure out which PLT chunk to resize. Usually "last index = size - 1" since the index starts at zero, but in this context, the size has just been decremented so there's no need to subtract one. */ reloc_index = srel->size / sizeof (Elf32_External_Rela); chunk = reloc_index / PLT_ENTRIES_PER_CHUNK; splt = elf_xtensa_get_plt_section (info, chunk); sgotplt = elf_xtensa_get_gotplt_section (info, chunk); BFD_ASSERT (splt != NULL && sgotplt != NULL); /* Check if an entire PLT chunk has just been eliminated. */ if (reloc_index % PLT_ENTRIES_PER_CHUNK == 0) { /* The two magic GOT entries for that chunk can go away. */ srelgot = htab->srelgot; BFD_ASSERT (srelgot != NULL); srelgot->reloc_count -= 2; srelgot->size -= 2 * sizeof (Elf32_External_Rela); sgotplt->size -= 8; /* There should be only one entry left (and it will be removed below). */ BFD_ASSERT (sgotplt->size == 4); BFD_ASSERT (splt->size == PLT_ENTRY_SIZE); } BFD_ASSERT (sgotplt->size >= 4); BFD_ASSERT (splt->size >= PLT_ENTRY_SIZE); sgotplt->size -= 4; splt->size -= PLT_ENTRY_SIZE; } } } /* Take an r_rel and move it to another section. This usually requires extending the interal_relocation array and pinning it. If the original r_rel is from the same BFD, we can complete this here. Otherwise, we add a fix record to let the final link fix the appropriate address. Contents and internal relocations for the section must be pinned after calling this routine. */ static bfd_boolean move_literal (bfd *abfd, struct bfd_link_info *link_info, asection *sec, bfd_vma offset, bfd_byte *contents, xtensa_relax_info *relax_info, Elf_Internal_Rela **internal_relocs_p, const literal_value *lit) { Elf_Internal_Rela *new_relocs = NULL; size_t new_relocs_count = 0; Elf_Internal_Rela this_rela; const r_reloc *r_rel; r_rel = &lit->r_rel; BFD_ASSERT (elf_section_data (sec)->relocs == *internal_relocs_p); if (r_reloc_is_const (r_rel)) bfd_put_32 (abfd, lit->value, contents + offset); else { int r_type; unsigned i; reloc_bfd_fix *fix; unsigned insert_at; r_type = ELF32_R_TYPE (r_rel->rela.r_info); /* This is the difficult case. We have to create a fix up. */ this_rela.r_offset = offset; this_rela.r_info = ELF32_R_INFO (0, r_type); this_rela.r_addend = r_rel->target_offset - r_reloc_get_target_offset (r_rel); bfd_put_32 (abfd, lit->value, contents + offset); /* Currently, we cannot move relocations during a relocatable link. */ BFD_ASSERT (!link_info->relocatable); fix = reloc_bfd_fix_init (sec, offset, r_type, r_reloc_get_section (r_rel), r_rel->target_offset + r_rel->virtual_offset, FALSE); /* We also need to mark that relocations are needed here. */ sec->flags |= SEC_RELOC; translate_reloc_bfd_fix (fix); /* This fix has not yet been translated. */ add_fix (sec, fix); /* Add the relocation. If we have already allocated our own space for the relocations and we have room for more, then use it. Otherwise, allocate new space and move the literals. */ insert_at = sec->reloc_count; for (i = 0; i < sec->reloc_count; ++i) { if (this_rela.r_offset < (*internal_relocs_p)[i].r_offset) { insert_at = i; break; } } if (*internal_relocs_p != relax_info->allocated_relocs || sec->reloc_count + 1 > relax_info->allocated_relocs_count) { BFD_ASSERT (relax_info->allocated_relocs == NULL || sec->reloc_count == relax_info->relocs_count); if (relax_info->allocated_relocs_count == 0) new_relocs_count = (sec->reloc_count + 2) * 2; else new_relocs_count = (relax_info->allocated_relocs_count + 2) * 2; new_relocs = (Elf_Internal_Rela *) bfd_zmalloc (sizeof (Elf_Internal_Rela) * (new_relocs_count)); if (!new_relocs) return FALSE; /* We could handle this more quickly by finding the split point. */ if (insert_at != 0) memcpy (new_relocs, *internal_relocs_p, insert_at * sizeof (Elf_Internal_Rela)); new_relocs[insert_at] = this_rela; if (insert_at != sec->reloc_count) memcpy (new_relocs + insert_at + 1, (*internal_relocs_p) + insert_at, (sec->reloc_count - insert_at) * sizeof (Elf_Internal_Rela)); if (*internal_relocs_p != relax_info->allocated_relocs) { /* The first time we re-allocate, we can only free the old relocs if they were allocated with bfd_malloc. This is not true when keep_memory is in effect. */ if (!link_info->keep_memory) free (*internal_relocs_p); } else free (*internal_relocs_p); relax_info->allocated_relocs = new_relocs; relax_info->allocated_relocs_count = new_relocs_count; elf_section_data (sec)->relocs = new_relocs; sec->reloc_count++; relax_info->relocs_count = sec->reloc_count; *internal_relocs_p = new_relocs; } else { if (insert_at != sec->reloc_count) { unsigned idx; for (idx = sec->reloc_count; idx > insert_at; idx--) (*internal_relocs_p)[idx] = (*internal_relocs_p)[idx-1]; } (*internal_relocs_p)[insert_at] = this_rela; sec->reloc_count++; if (relax_info->allocated_relocs) relax_info->relocs_count = sec->reloc_count; } } return TRUE; } /* This is similar to relax_section except that when a target is moved, we shift addresses up. We also need to modify the size. This algorithm does NOT allow for relocations into the middle of the property sections. */ static bfd_boolean relax_property_section (bfd *abfd, asection *sec, struct bfd_link_info *link_info) { Elf_Internal_Rela *internal_relocs; bfd_byte *contents; unsigned i; bfd_boolean ok = TRUE; bfd_boolean is_full_prop_section; size_t last_zfill_target_offset = 0; asection *last_zfill_target_sec = NULL; bfd_size_type sec_size; bfd_size_type entry_size; sec_size = bfd_get_section_limit (abfd, sec); internal_relocs = retrieve_internal_relocs (abfd, sec, link_info->keep_memory); contents = retrieve_contents (abfd, sec, link_info->keep_memory); if (contents == NULL && sec_size != 0) { ok = FALSE; goto error_return; } is_full_prop_section = xtensa_is_proptable_section (sec); if (is_full_prop_section) entry_size = 12; else entry_size = 8; if (internal_relocs) { for (i = 0; i < sec->reloc_count; i++) { Elf_Internal_Rela *irel; xtensa_relax_info *target_relax_info; unsigned r_type; asection *target_sec; literal_value val; bfd_byte *size_p, *flags_p; /* Locally change the source address. Translate the target to the new target address. If it points to this section and has been removed, MOVE IT. Also, don't forget to modify the associated SIZE at (offset + 4). */ irel = &internal_relocs[i]; r_type = ELF32_R_TYPE (irel->r_info); if (r_type == R_XTENSA_NONE) continue; /* Find the literal value. */ r_reloc_init (&val.r_rel, abfd, irel, contents, sec_size); size_p = &contents[irel->r_offset + 4]; flags_p = NULL; if (is_full_prop_section) flags_p = &contents[irel->r_offset + 8]; BFD_ASSERT (irel->r_offset + entry_size <= sec_size); target_sec = r_reloc_get_section (&val.r_rel); target_relax_info = get_xtensa_relax_info (target_sec); if (target_relax_info && (target_relax_info->is_relaxable_literal_section || target_relax_info->is_relaxable_asm_section )) { /* Translate the relocation's destination. */ bfd_vma old_offset = val.r_rel.target_offset; bfd_vma new_offset; long old_size, new_size; text_action *act = target_relax_info->action_list.head; new_offset = old_offset - removed_by_actions (&act, old_offset, FALSE); /* Assert that we are not out of bounds. */ old_size = bfd_get_32 (abfd, size_p); new_size = old_size; if (old_size == 0) { /* Only the first zero-sized unreachable entry is allowed to expand. In this case the new offset should be the offset before the fill and the new size is the expansion size. For other zero-sized entries the resulting size should be zero with an offset before or after the fill address depending on whether the expanding unreachable entry preceeds it. */ if (last_zfill_target_sec == 0 || last_zfill_target_sec != target_sec || last_zfill_target_offset != old_offset) { bfd_vma new_end_offset = new_offset; /* Recompute the new_offset, but this time don't include any fill inserted by relaxation. */ act = target_relax_info->action_list.head; new_offset = old_offset - removed_by_actions (&act, old_offset, TRUE); /* If it is not unreachable and we have not yet seen an unreachable at this address, place it before the fill address. */ if (flags_p && (bfd_get_32 (abfd, flags_p) & XTENSA_PROP_UNREACHABLE) != 0) { new_size = new_end_offset - new_offset; last_zfill_target_sec = target_sec; last_zfill_target_offset = old_offset; } } } else new_size -= removed_by_actions (&act, old_offset + old_size, TRUE); if (new_size != old_size) { bfd_put_32 (abfd, new_size, size_p); pin_contents (sec, contents); } if (new_offset != old_offset) { bfd_vma diff = new_offset - old_offset; irel->r_addend += diff; pin_internal_relocs (sec, internal_relocs); } } } } /* Combine adjacent property table entries. This is also done in finish_dynamic_sections() but at that point it's too late to reclaim the space in the output section, so we do this twice. */ if (internal_relocs && (!link_info->relocatable || xtensa_is_littable_section (sec))) { Elf_Internal_Rela *last_irel = NULL; Elf_Internal_Rela *irel, *next_rel, *rel_end; int removed_bytes = 0; bfd_vma offset; flagword predef_flags; predef_flags = xtensa_get_property_predef_flags (sec); /* Walk over memory and relocations at the same time. This REQUIRES that the internal_relocs be sorted by offset. */ qsort (internal_relocs, sec->reloc_count, sizeof (Elf_Internal_Rela), internal_reloc_compare); pin_internal_relocs (sec, internal_relocs); pin_contents (sec, contents); next_rel = internal_relocs; rel_end = internal_relocs + sec->reloc_count; BFD_ASSERT (sec->size % entry_size == 0); for (offset = 0; offset < sec->size; offset += entry_size) { Elf_Internal_Rela *offset_rel, *extra_rel; bfd_vma bytes_to_remove, size, actual_offset; bfd_boolean remove_this_rel; flagword flags; /* Find the first relocation for the entry at the current offset. Adjust the offsets of any extra relocations for the previous entry. */ offset_rel = NULL; if (next_rel) { for (irel = next_rel; irel < rel_end; irel++) { if ((irel->r_offset == offset && ELF32_R_TYPE (irel->r_info) != R_XTENSA_NONE) || irel->r_offset > offset) { offset_rel = irel; break; } irel->r_offset -= removed_bytes; } } /* Find the next relocation (if there are any left). */ extra_rel = NULL; if (offset_rel) { for (irel = offset_rel + 1; irel < rel_end; irel++) { if (ELF32_R_TYPE (irel->r_info) != R_XTENSA_NONE) { extra_rel = irel; break; } } } /* Check if there are relocations on the current entry. There should usually be a relocation on the offset field. If there are relocations on the size or flags, then we can't optimize this entry. Also, find the next relocation to examine on the next iteration. */ if (offset_rel) { if (offset_rel->r_offset >= offset + entry_size) { next_rel = offset_rel; /* There are no relocations on the current entry, but we might still be able to remove it if the size is zero. */ offset_rel = NULL; } else if (offset_rel->r_offset > offset || (extra_rel && extra_rel->r_offset < offset + entry_size)) { /* There is a relocation on the size or flags, so we can't do anything with this entry. Continue with the next. */ next_rel = offset_rel; continue; } else { BFD_ASSERT (offset_rel->r_offset == offset); offset_rel->r_offset -= removed_bytes; next_rel = offset_rel + 1; } } else next_rel = NULL; remove_this_rel = FALSE; bytes_to_remove = 0; actual_offset = offset - removed_bytes; size = bfd_get_32 (abfd, &contents[actual_offset + 4]); if (is_full_prop_section) flags = bfd_get_32 (abfd, &contents[actual_offset + 8]); else flags = predef_flags; if (size == 0 && (flags & XTENSA_PROP_ALIGN) == 0 && (flags & XTENSA_PROP_UNREACHABLE) == 0) { /* Always remove entries with zero size and no alignment. */ bytes_to_remove = entry_size; if (offset_rel) remove_this_rel = TRUE; } else if (offset_rel && ELF32_R_TYPE (offset_rel->r_info) == R_XTENSA_32) { if (last_irel) { flagword old_flags; bfd_vma old_size = bfd_get_32 (abfd, &contents[last_irel->r_offset + 4]); bfd_vma old_address = (last_irel->r_addend + bfd_get_32 (abfd, &contents[last_irel->r_offset])); bfd_vma new_address = (offset_rel->r_addend + bfd_get_32 (abfd, &contents[actual_offset])); if (is_full_prop_section) old_flags = bfd_get_32 (abfd, &contents[last_irel->r_offset + 8]); else old_flags = predef_flags; if ((ELF32_R_SYM (offset_rel->r_info) == ELF32_R_SYM (last_irel->r_info)) && old_address + old_size == new_address && old_flags == flags && (old_flags & XTENSA_PROP_INSN_BRANCH_TARGET) == 0 && (old_flags & XTENSA_PROP_INSN_LOOP_TARGET) == 0) { /* Fix the old size. */ bfd_put_32 (abfd, old_size + size, &contents[last_irel->r_offset + 4]); bytes_to_remove = entry_size; remove_this_rel = TRUE; } else last_irel = offset_rel; } else last_irel = offset_rel; } if (remove_this_rel) { offset_rel->r_info = ELF32_R_INFO (0, R_XTENSA_NONE); offset_rel->r_offset = 0; } if (bytes_to_remove != 0) { removed_bytes += bytes_to_remove; if (offset + bytes_to_remove < sec->size) memmove (&contents[actual_offset], &contents[actual_offset + bytes_to_remove], sec->size - offset - bytes_to_remove); } } if (removed_bytes) { /* Fix up any extra relocations on the last entry. */ for (irel = next_rel; irel < rel_end; irel++) irel->r_offset -= removed_bytes; /* Clear the removed bytes. */ memset (&contents[sec->size - removed_bytes], 0, removed_bytes); if (sec->rawsize == 0) sec->rawsize = sec->size; sec->size -= removed_bytes; if (xtensa_is_littable_section (sec)) { asection *sgotloc = elf_xtensa_hash_table (link_info)->sgotloc; if (sgotloc) sgotloc->size -= removed_bytes; } } } error_return: release_internal_relocs (sec, internal_relocs); release_contents (sec, contents); return ok; } /* Third relaxation pass. */ /* Change symbol values to account for removed literals. */ bfd_boolean relax_section_symbols (bfd *abfd, asection *sec) { xtensa_relax_info *relax_info; unsigned int sec_shndx; Elf_Internal_Shdr *symtab_hdr; Elf_Internal_Sym *isymbuf; unsigned i, num_syms, num_locals; relax_info = get_xtensa_relax_info (sec); BFD_ASSERT (relax_info); if (!relax_info->is_relaxable_literal_section && !relax_info->is_relaxable_asm_section) return TRUE; sec_shndx = _bfd_elf_section_from_bfd_section (abfd, sec); symtab_hdr = &elf_tdata (abfd)->symtab_hdr; isymbuf = retrieve_local_syms (abfd); num_syms = symtab_hdr->sh_size / sizeof (Elf32_External_Sym); num_locals = symtab_hdr->sh_info; /* Adjust the local symbols defined in this section. */ for (i = 0; i < num_locals; i++) { Elf_Internal_Sym *isym = &isymbuf[i]; if (isym->st_shndx == sec_shndx) { text_action *act = relax_info->action_list.head; bfd_vma orig_addr = isym->st_value; isym->st_value -= removed_by_actions (&act, orig_addr, FALSE); if (ELF32_ST_TYPE (isym->st_info) == STT_FUNC) isym->st_size -= removed_by_actions (&act, orig_addr + isym->st_size, FALSE); } } /* Now adjust the global symbols defined in this section. */ for (i = 0; i < (num_syms - num_locals); i++) { struct elf_link_hash_entry *sym_hash; sym_hash = elf_sym_hashes (abfd)[i]; if (sym_hash->root.type == bfd_link_hash_warning) sym_hash = (struct elf_link_hash_entry *) sym_hash->root.u.i.link; if ((sym_hash->root.type == bfd_link_hash_defined || sym_hash->root.type == bfd_link_hash_defweak) && sym_hash->root.u.def.section == sec) { text_action *act = relax_info->action_list.head; bfd_vma orig_addr = sym_hash->root.u.def.value; sym_hash->root.u.def.value -= removed_by_actions (&act, orig_addr, FALSE); if (sym_hash->type == STT_FUNC) sym_hash->size -= removed_by_actions (&act, orig_addr + sym_hash->size, FALSE); } } return TRUE; } /* "Fix" handling functions, called while performing relocations. */ static bfd_boolean do_fix_for_relocatable_link (Elf_Internal_Rela *rel, bfd *input_bfd, asection *input_section, bfd_byte *contents) { r_reloc r_rel; asection *sec, *old_sec; bfd_vma old_offset; int r_type = ELF32_R_TYPE (rel->r_info); reloc_bfd_fix *fix; if (r_type == R_XTENSA_NONE) return TRUE; fix = get_bfd_fix (input_section, rel->r_offset, r_type); if (!fix) return TRUE; r_reloc_init (&r_rel, input_bfd, rel, contents, bfd_get_section_limit (input_bfd, input_section)); old_sec = r_reloc_get_section (&r_rel); old_offset = r_rel.target_offset; if (!old_sec || !r_reloc_is_defined (&r_rel)) { if (r_type != R_XTENSA_ASM_EXPAND) { (*_bfd_error_handler) (_("%B(%A+0x%lx): unexpected fix for %s relocation"), input_bfd, input_section, rel->r_offset, elf_howto_table[r_type].name); return FALSE; } /* Leave it be. Resolution will happen in a later stage. */ } else { sec = fix->target_sec; rel->r_addend += ((sec->output_offset + fix->target_offset) - (old_sec->output_offset + old_offset)); } return TRUE; } static void do_fix_for_final_link (Elf_Internal_Rela *rel, bfd *input_bfd, asection *input_section, bfd_byte *contents, bfd_vma *relocationp) { asection *sec; int r_type = ELF32_R_TYPE (rel->r_info); reloc_bfd_fix *fix; bfd_vma fixup_diff; if (r_type == R_XTENSA_NONE) return; fix = get_bfd_fix (input_section, rel->r_offset, r_type); if (!fix) return; sec = fix->target_sec; fixup_diff = rel->r_addend; if (elf_howto_table[fix->src_type].partial_inplace) { bfd_vma inplace_val; BFD_ASSERT (fix->src_offset < bfd_get_section_limit (input_bfd, input_section)); inplace_val = bfd_get_32 (input_bfd, &contents[fix->src_offset]); fixup_diff += inplace_val; } *relocationp = (sec->output_section->vma + sec->output_offset + fix->target_offset - fixup_diff); } /* Miscellaneous utility functions.... */ static asection * elf_xtensa_get_plt_section (struct bfd_link_info *info, int chunk) { struct elf_xtensa_link_hash_table *htab; bfd *dynobj; char plt_name[10]; if (chunk == 0) { htab = elf_xtensa_hash_table (info); if (htab == NULL) return NULL; return htab->splt; } dynobj = elf_hash_table (info)->dynobj; sprintf (plt_name, ".plt.%u", chunk); return bfd_get_section_by_name (dynobj, plt_name); } static asection * elf_xtensa_get_gotplt_section (struct bfd_link_info *info, int chunk) { struct elf_xtensa_link_hash_table *htab; bfd *dynobj; char got_name[14]; if (chunk == 0) { htab = elf_xtensa_hash_table (info); if (htab == NULL) return NULL; return htab->sgotplt; } dynobj = elf_hash_table (info)->dynobj; sprintf (got_name, ".got.plt.%u", chunk); return bfd_get_section_by_name (dynobj, got_name); } /* Get the input section for a given symbol index. If the symbol is: . a section symbol, return the section; . a common symbol, return the common section; . an undefined symbol, return the undefined section; . an indirect symbol, follow the links; . an absolute value, return the absolute section. */ static asection * get_elf_r_symndx_section (bfd *abfd, unsigned long r_symndx) { Elf_Internal_Shdr *symtab_hdr = &elf_tdata (abfd)->symtab_hdr; asection *target_sec = NULL; if (r_symndx < symtab_hdr->sh_info) { Elf_Internal_Sym *isymbuf; unsigned int section_index; isymbuf = retrieve_local_syms (abfd); section_index = isymbuf[r_symndx].st_shndx; if (section_index == SHN_UNDEF) target_sec = bfd_und_section_ptr; else if (section_index == SHN_ABS) target_sec = bfd_abs_section_ptr; else if (section_index == SHN_COMMON) target_sec = bfd_com_section_ptr; else target_sec = bfd_section_from_elf_index (abfd, section_index); } else { unsigned long indx = r_symndx - symtab_hdr->sh_info; struct elf_link_hash_entry *h = elf_sym_hashes (abfd)[indx]; while (h->root.type == bfd_link_hash_indirect || h->root.type == bfd_link_hash_warning) h = (struct elf_link_hash_entry *) h->root.u.i.link; switch (h->root.type) { case bfd_link_hash_defined: case bfd_link_hash_defweak: target_sec = h->root.u.def.section; break; case bfd_link_hash_common: target_sec = bfd_com_section_ptr; break; case bfd_link_hash_undefined: case bfd_link_hash_undefweak: target_sec = bfd_und_section_ptr; break; default: /* New indirect warning. */ target_sec = bfd_und_section_ptr; break; } } return target_sec; } static struct elf_link_hash_entry * get_elf_r_symndx_hash_entry (bfd *abfd, unsigned long r_symndx) { unsigned long indx; struct elf_link_hash_entry *h; Elf_Internal_Shdr *symtab_hdr = &elf_tdata (abfd)->symtab_hdr; if (r_symndx < symtab_hdr->sh_info) return NULL; indx = r_symndx - symtab_hdr->sh_info; h = elf_sym_hashes (abfd)[indx]; while (h->root.type == bfd_link_hash_indirect || h->root.type == bfd_link_hash_warning) h = (struct elf_link_hash_entry *) h->root.u.i.link; return h; } /* Get the section-relative offset for a symbol number. */ static bfd_vma get_elf_r_symndx_offset (bfd *abfd, unsigned long r_symndx) { Elf_Internal_Shdr *symtab_hdr = &elf_tdata (abfd)->symtab_hdr; bfd_vma offset = 0; if (r_symndx < symtab_hdr->sh_info) { Elf_Internal_Sym *isymbuf; isymbuf = retrieve_local_syms (abfd); offset = isymbuf[r_symndx].st_value; } else { unsigned long indx = r_symndx - symtab_hdr->sh_info; struct elf_link_hash_entry *h = elf_sym_hashes (abfd)[indx]; while (h->root.type == bfd_link_hash_indirect || h->root.type == bfd_link_hash_warning) h = (struct elf_link_hash_entry *) h->root.u.i.link; if (h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak) offset = h->root.u.def.value; } return offset; } static bfd_boolean is_reloc_sym_weak (bfd *abfd, Elf_Internal_Rela *rel) { unsigned long r_symndx = ELF32_R_SYM (rel->r_info); struct elf_link_hash_entry *h; h = get_elf_r_symndx_hash_entry (abfd, r_symndx); if (h && h->root.type == bfd_link_hash_defweak) return TRUE; return FALSE; } static bfd_boolean pcrel_reloc_fits (xtensa_opcode opc, int opnd, bfd_vma self_address, bfd_vma dest_address) { xtensa_isa isa = xtensa_default_isa; uint32 valp = dest_address; if (xtensa_operand_do_reloc (isa, opc, opnd, &valp, self_address) || xtensa_operand_encode (isa, opc, opnd, &valp)) return FALSE; return TRUE; } static bfd_boolean xtensa_is_property_section (asection *sec) { if (xtensa_is_insntable_section (sec) || xtensa_is_littable_section (sec) || xtensa_is_proptable_section (sec)) return TRUE; return FALSE; } static bfd_boolean xtensa_is_insntable_section (asection *sec) { if (CONST_STRNEQ (sec->name, XTENSA_INSN_SEC_NAME) || CONST_STRNEQ (sec->name, ".gnu.linkonce.x.")) return TRUE; return FALSE; } static bfd_boolean xtensa_is_littable_section (asection *sec) { if (CONST_STRNEQ (sec->name, XTENSA_LIT_SEC_NAME) || CONST_STRNEQ (sec->name, ".gnu.linkonce.p.")) return TRUE; return FALSE; } static bfd_boolean xtensa_is_proptable_section (asection *sec) { if (CONST_STRNEQ (sec->name, XTENSA_PROP_SEC_NAME) || CONST_STRNEQ (sec->name, ".gnu.linkonce.prop.")) return TRUE; return FALSE; } static int internal_reloc_compare (const void *ap, const void *bp) { const Elf_Internal_Rela *a = (const Elf_Internal_Rela *) ap; const Elf_Internal_Rela *b = (const Elf_Internal_Rela *) bp; if (a->r_offset != b->r_offset) return (a->r_offset - b->r_offset); /* We don't need to sort on these criteria for correctness, but enforcing a more strict ordering prevents unstable qsort from behaving differently with different implementations. Without the code below we get correct but different results on Solaris 2.7 and 2.8. We would like to always produce the same results no matter the host. */ if (a->r_info != b->r_info) return (a->r_info - b->r_info); return (a->r_addend - b->r_addend); } static int internal_reloc_matches (const void *ap, const void *bp) { const Elf_Internal_Rela *a = (const Elf_Internal_Rela *) ap; const Elf_Internal_Rela *b = (const Elf_Internal_Rela *) bp; /* Check if one entry overlaps with the other; this shouldn't happen except when searching for a match. */ return (a->r_offset - b->r_offset); } /* Predicate function used to look up a section in a particular group. */ static bfd_boolean match_section_group (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *inf) { const char *gname = inf; const char *group_name = elf_group_name (sec); return (group_name == gname || (group_name != NULL && gname != NULL && strcmp (group_name, gname) == 0)); } static int linkonce_len = sizeof (".gnu.linkonce.") - 1; static char * xtensa_property_section_name (asection *sec, const char *base_name) { const char *suffix, *group_name; char *prop_sec_name; group_name = elf_group_name (sec); if (group_name) { suffix = strrchr (sec->name, '.'); if (suffix == sec->name) suffix = 0; prop_sec_name = (char *) bfd_malloc (strlen (base_name) + 1 + (suffix ? strlen (suffix) : 0)); strcpy (prop_sec_name, base_name); if (suffix) strcat (prop_sec_name, suffix); } else if (strncmp (sec->name, ".gnu.linkonce.", linkonce_len) == 0) { char *linkonce_kind = 0; if (strcmp (base_name, XTENSA_INSN_SEC_NAME) == 0) linkonce_kind = "x."; else if (strcmp (base_name, XTENSA_LIT_SEC_NAME) == 0) linkonce_kind = "p."; else if (strcmp (base_name, XTENSA_PROP_SEC_NAME) == 0) linkonce_kind = "prop."; else abort (); prop_sec_name = (char *) bfd_malloc (strlen (sec->name) + strlen (linkonce_kind) + 1); memcpy (prop_sec_name, ".gnu.linkonce.", linkonce_len); strcpy (prop_sec_name + linkonce_len, linkonce_kind); suffix = sec->name + linkonce_len; /* For backward compatibility, replace "t." instead of inserting the new linkonce_kind (but not for "prop" sections). */ if (CONST_STRNEQ (suffix, "t.") && linkonce_kind[1] == '.') suffix += 2; strcat (prop_sec_name + linkonce_len, suffix); } else prop_sec_name = strdup (base_name); return prop_sec_name; } static asection * xtensa_get_property_section (asection *sec, const char *base_name) { char *prop_sec_name; asection *prop_sec; prop_sec_name = xtensa_property_section_name (sec, base_name); prop_sec = bfd_get_section_by_name_if (sec->owner, prop_sec_name, match_section_group, (void *) elf_group_name (sec)); free (prop_sec_name); return prop_sec; } asection * xtensa_make_property_section (asection *sec, const char *base_name) { char *prop_sec_name; asection *prop_sec; /* Check if the section already exists. */ prop_sec_name = xtensa_property_section_name (sec, base_name); prop_sec = bfd_get_section_by_name_if (sec->owner, prop_sec_name, match_section_group, (void *) elf_group_name (sec)); /* If not, create it. */ if (! prop_sec) { flagword flags = (SEC_RELOC | SEC_HAS_CONTENTS | SEC_READONLY); flags |= (bfd_get_section_flags (sec->owner, sec) & (SEC_LINK_ONCE | SEC_LINK_DUPLICATES)); prop_sec = bfd_make_section_anyway_with_flags (sec->owner, strdup (prop_sec_name), flags); if (! prop_sec) return 0; elf_group_name (prop_sec) = elf_group_name (sec); } free (prop_sec_name); return prop_sec; } flagword xtensa_get_property_predef_flags (asection *sec) { if (xtensa_is_insntable_section (sec)) return (XTENSA_PROP_INSN | XTENSA_PROP_NO_TRANSFORM | XTENSA_PROP_INSN_NO_REORDER); if (xtensa_is_littable_section (sec)) return (XTENSA_PROP_LITERAL | XTENSA_PROP_NO_TRANSFORM | XTENSA_PROP_INSN_NO_REORDER); return 0; } /* Other functions called directly by the linker. */ bfd_boolean xtensa_callback_required_dependence (bfd *abfd, asection *sec, struct bfd_link_info *link_info, deps_callback_t callback, void *closure) { Elf_Internal_Rela *internal_relocs; bfd_byte *contents; unsigned i; bfd_boolean ok = TRUE; bfd_size_type sec_size; sec_size = bfd_get_section_limit (abfd, sec); /* ".plt*" sections have no explicit relocations but they contain L32R instructions that reference the corresponding ".got.plt*" sections. */ if ((sec->flags & SEC_LINKER_CREATED) != 0 && CONST_STRNEQ (sec->name, ".plt")) { asection *sgotplt; /* Find the corresponding ".got.plt*" section. */ if (sec->name[4] == '\0') sgotplt = bfd_get_section_by_name (sec->owner, ".got.plt"); else { char got_name[14]; int chunk = 0; BFD_ASSERT (sec->name[4] == '.'); chunk = strtol (&sec->name[5], NULL, 10); sprintf (got_name, ".got.plt.%u", chunk); sgotplt = bfd_get_section_by_name (sec->owner, got_name); } BFD_ASSERT (sgotplt); /* Assume worst-case offsets: L32R at the very end of the ".plt" section referencing a literal at the very beginning of ".got.plt". This is very close to the real dependence, anyway. */ (*callback) (sec, sec_size, sgotplt, 0, closure); } /* Only ELF files are supported for Xtensa. Check here to avoid a segfault when building uclibc, which runs "ld -b binary /dev/null". */ if (bfd_get_flavour (abfd) != bfd_target_elf_flavour) return ok; internal_relocs = retrieve_internal_relocs (abfd, sec, link_info->keep_memory); if (internal_relocs == NULL || sec->reloc_count == 0) return ok; /* Cache the contents for the duration of this scan. */ contents = retrieve_contents (abfd, sec, link_info->keep_memory); if (contents == NULL && sec_size != 0) { ok = FALSE; goto error_return; } if (!xtensa_default_isa) xtensa_default_isa = xtensa_isa_init (0, 0); for (i = 0; i < sec->reloc_count; i++) { Elf_Internal_Rela *irel = &internal_relocs[i]; if (is_l32r_relocation (abfd, sec, contents, irel)) { r_reloc l32r_rel; asection *target_sec; bfd_vma target_offset; r_reloc_init (&l32r_rel, abfd, irel, contents, sec_size); target_sec = NULL; target_offset = 0; /* L32Rs must be local to the input file. */ if (r_reloc_is_defined (&l32r_rel)) { target_sec = r_reloc_get_section (&l32r_rel); target_offset = l32r_rel.target_offset; } (*callback) (sec, irel->r_offset, target_sec, target_offset, closure); } } error_return: release_internal_relocs (sec, internal_relocs); release_contents (sec, contents); return ok; } /* The default literal sections should always be marked as "code" (i.e., SHF_EXECINSTR). This is particularly important for the Linux kernel module loader so that the literals are not placed after the text. */ static const struct bfd_elf_special_section elf_xtensa_special_sections[] = { { STRING_COMMA_LEN (".fini.literal"), 0, SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR }, { STRING_COMMA_LEN (".init.literal"), 0, SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR }, { STRING_COMMA_LEN (".literal"), 0, SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR }, { STRING_COMMA_LEN (".xtensa.info"), 0, SHT_NOTE, 0 }, { NULL, 0, 0, 0, 0 } }; #define ELF_TARGET_ID XTENSA_ELF_DATA #ifndef ELF_ARCH #define TARGET_LITTLE_SYM bfd_elf32_xtensa_le_vec #define TARGET_LITTLE_NAME "elf32-xtensa-le" #define TARGET_BIG_SYM bfd_elf32_xtensa_be_vec #define TARGET_BIG_NAME "elf32-xtensa-be" #define ELF_ARCH bfd_arch_xtensa #define ELF_MACHINE_CODE EM_XTENSA #define ELF_MACHINE_ALT1 EM_XTENSA_OLD #if XCHAL_HAVE_MMU #define ELF_MAXPAGESIZE (1 << XCHAL_MMU_MIN_PTE_PAGE_SIZE) #else /* !XCHAL_HAVE_MMU */ #define ELF_MAXPAGESIZE 1 #endif /* !XCHAL_HAVE_MMU */ #endif /* ELF_ARCH */ #define elf_backend_can_gc_sections 1 #define elf_backend_can_refcount 1 #define elf_backend_plt_readonly 1 #define elf_backend_got_header_size 4 #define elf_backend_want_dynbss 0 #define elf_backend_want_got_plt 1 #define elf_info_to_howto elf_xtensa_info_to_howto_rela #define bfd_elf32_mkobject elf_xtensa_mkobject #define bfd_elf32_bfd_merge_private_bfd_data elf_xtensa_merge_private_bfd_data #define bfd_elf32_new_section_hook elf_xtensa_new_section_hook #define bfd_elf32_bfd_print_private_bfd_data elf_xtensa_print_private_bfd_data #define bfd_elf32_bfd_relax_section elf_xtensa_relax_section #define bfd_elf32_bfd_reloc_type_lookup elf_xtensa_reloc_type_lookup #define bfd_elf32_bfd_reloc_name_lookup \ elf_xtensa_reloc_name_lookup #define bfd_elf32_bfd_set_private_flags elf_xtensa_set_private_flags #define bfd_elf32_bfd_link_hash_table_create elf_xtensa_link_hash_table_create #define elf_backend_adjust_dynamic_symbol elf_xtensa_adjust_dynamic_symbol #define elf_backend_check_relocs elf_xtensa_check_relocs #define elf_backend_create_dynamic_sections elf_xtensa_create_dynamic_sections #define elf_backend_discard_info elf_xtensa_discard_info #define elf_backend_ignore_discarded_relocs elf_xtensa_ignore_discarded_relocs #define elf_backend_final_write_processing elf_xtensa_final_write_processing #define elf_backend_finish_dynamic_sections elf_xtensa_finish_dynamic_sections #define elf_backend_finish_dynamic_symbol elf_xtensa_finish_dynamic_symbol #define elf_backend_gc_mark_hook elf_xtensa_gc_mark_hook #define elf_backend_gc_sweep_hook elf_xtensa_gc_sweep_hook #define elf_backend_grok_prstatus elf_xtensa_grok_prstatus #define elf_backend_grok_psinfo elf_xtensa_grok_psinfo #define elf_backend_hide_symbol elf_xtensa_hide_symbol #define elf_backend_object_p elf_xtensa_object_p #define elf_backend_reloc_type_class elf_xtensa_reloc_type_class #define elf_backend_relocate_section elf_xtensa_relocate_section #define elf_backend_size_dynamic_sections elf_xtensa_size_dynamic_sections #define elf_backend_always_size_sections elf_xtensa_always_size_sections #define elf_backend_omit_section_dynsym \ ((bfd_boolean (*) (bfd *, struct bfd_link_info *, asection *)) bfd_true) #define elf_backend_special_sections elf_xtensa_special_sections #define elf_backend_action_discarded elf_xtensa_action_discarded #define elf_backend_copy_indirect_symbol elf_xtensa_copy_indirect_symbol #include "elf32-target.h"
Go to most recent revision | Compare with Previous | Blame | View Log