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[/] [open8_urisc/] [trunk/] [gnu/] [binutils/] [bfd/] [elf32-i386.c] - Rev 249
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/* Intel 80386/80486-specific support for 32-bit ELF Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 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 "bfdlink.h" #include "libbfd.h" #include "elf-bfd.h" #include "elf-vxworks.h" #include "bfd_stdint.h" #include "objalloc.h" #include "hashtab.h" #include "dwarf2.h" /* 386 uses REL relocations instead of RELA. */ #define USE_REL 1 #include "elf/i386.h" static reloc_howto_type elf_howto_table[]= { HOWTO(R_386_NONE, 0, 0, 0, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_NONE", TRUE, 0x00000000, 0x00000000, FALSE), HOWTO(R_386_32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_32", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_PC32, 0, 2, 32, TRUE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_PC32", TRUE, 0xffffffff, 0xffffffff, TRUE), HOWTO(R_386_GOT32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_GOT32", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_PLT32, 0, 2, 32, TRUE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_PLT32", TRUE, 0xffffffff, 0xffffffff, TRUE), HOWTO(R_386_COPY, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_COPY", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_GLOB_DAT, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_GLOB_DAT", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_JUMP_SLOT, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_JUMP_SLOT", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_RELATIVE, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_RELATIVE", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_GOTOFF, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_GOTOFF", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_GOTPC, 0, 2, 32, TRUE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_GOTPC", TRUE, 0xffffffff, 0xffffffff, TRUE), /* We have a gap in the reloc numbers here. R_386_standard counts the number up to this point, and R_386_ext_offset is the value to subtract from a reloc type of R_386_16 thru R_386_PC8 to form an index into this table. */ #define R_386_standard (R_386_GOTPC + 1) #define R_386_ext_offset (R_386_TLS_TPOFF - R_386_standard) /* These relocs are a GNU extension. */ HOWTO(R_386_TLS_TPOFF, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_TPOFF", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_TLS_IE, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_IE", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_TLS_GOTIE, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_GOTIE", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_TLS_LE, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_LE", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_TLS_GD, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_GD", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_TLS_LDM, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_LDM", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_16, 0, 1, 16, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_16", TRUE, 0xffff, 0xffff, FALSE), HOWTO(R_386_PC16, 0, 1, 16, TRUE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_PC16", TRUE, 0xffff, 0xffff, TRUE), HOWTO(R_386_8, 0, 0, 8, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_8", TRUE, 0xff, 0xff, FALSE), HOWTO(R_386_PC8, 0, 0, 8, TRUE, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_386_PC8", TRUE, 0xff, 0xff, TRUE), #define R_386_ext (R_386_PC8 + 1 - R_386_ext_offset) #define R_386_tls_offset (R_386_TLS_LDO_32 - R_386_ext) /* These are common with Solaris TLS implementation. */ HOWTO(R_386_TLS_LDO_32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_LDO_32", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_TLS_IE_32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_IE_32", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_TLS_LE_32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_LE_32", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_TLS_DTPMOD32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_DTPMOD32", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_TLS_DTPOFF32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_DTPOFF32", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_TLS_TPOFF32, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_TPOFF32", TRUE, 0xffffffff, 0xffffffff, FALSE), EMPTY_HOWTO (38), HOWTO(R_386_TLS_GOTDESC, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_GOTDESC", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_TLS_DESC_CALL, 0, 0, 0, FALSE, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_386_TLS_DESC_CALL", FALSE, 0, 0, FALSE), HOWTO(R_386_TLS_DESC, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_TLS_DESC", TRUE, 0xffffffff, 0xffffffff, FALSE), HOWTO(R_386_IRELATIVE, 0, 2, 32, FALSE, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_386_IRELATIVE", TRUE, 0xffffffff, 0xffffffff, FALSE), /* Another gap. */ #define R_386_irelative (R_386_IRELATIVE + 1 - R_386_tls_offset) #define R_386_vt_offset (R_386_GNU_VTINHERIT - R_386_irelative) /* GNU extension to record C++ vtable hierarchy. */ HOWTO (R_386_GNU_VTINHERIT, /* type */ 0, /* rightshift */ 2, /* size (0 = byte, 1 = short, 2 = long) */ 0, /* bitsize */ FALSE, /* pc_relative */ 0, /* bitpos */ complain_overflow_dont, /* complain_on_overflow */ NULL, /* special_function */ "R_386_GNU_VTINHERIT", /* name */ FALSE, /* partial_inplace */ 0, /* src_mask */ 0, /* dst_mask */ FALSE), /* pcrel_offset */ /* GNU extension to record C++ vtable member usage. */ HOWTO (R_386_GNU_VTENTRY, /* type */ 0, /* rightshift */ 2, /* size (0 = byte, 1 = short, 2 = long) */ 0, /* bitsize */ FALSE, /* pc_relative */ 0, /* bitpos */ complain_overflow_dont, /* complain_on_overflow */ _bfd_elf_rel_vtable_reloc_fn, /* special_function */ "R_386_GNU_VTENTRY", /* name */ FALSE, /* partial_inplace */ 0, /* src_mask */ 0, /* dst_mask */ FALSE) /* pcrel_offset */ #define R_386_vt (R_386_GNU_VTENTRY + 1 - R_386_vt_offset) }; #ifdef DEBUG_GEN_RELOC #define TRACE(str) \ fprintf (stderr, "i386 bfd reloc lookup %d (%s)\n", code, str) #else #define TRACE(str) #endif static reloc_howto_type * elf_i386_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[R_386_NONE]; case BFD_RELOC_32: TRACE ("BFD_RELOC_32"); return &elf_howto_table[R_386_32]; case BFD_RELOC_CTOR: TRACE ("BFD_RELOC_CTOR"); return &elf_howto_table[R_386_32]; case BFD_RELOC_32_PCREL: TRACE ("BFD_RELOC_PC32"); return &elf_howto_table[R_386_PC32]; case BFD_RELOC_386_GOT32: TRACE ("BFD_RELOC_386_GOT32"); return &elf_howto_table[R_386_GOT32]; case BFD_RELOC_386_PLT32: TRACE ("BFD_RELOC_386_PLT32"); return &elf_howto_table[R_386_PLT32]; case BFD_RELOC_386_COPY: TRACE ("BFD_RELOC_386_COPY"); return &elf_howto_table[R_386_COPY]; case BFD_RELOC_386_GLOB_DAT: TRACE ("BFD_RELOC_386_GLOB_DAT"); return &elf_howto_table[R_386_GLOB_DAT]; case BFD_RELOC_386_JUMP_SLOT: TRACE ("BFD_RELOC_386_JUMP_SLOT"); return &elf_howto_table[R_386_JUMP_SLOT]; case BFD_RELOC_386_RELATIVE: TRACE ("BFD_RELOC_386_RELATIVE"); return &elf_howto_table[R_386_RELATIVE]; case BFD_RELOC_386_GOTOFF: TRACE ("BFD_RELOC_386_GOTOFF"); return &elf_howto_table[R_386_GOTOFF]; case BFD_RELOC_386_GOTPC: TRACE ("BFD_RELOC_386_GOTPC"); return &elf_howto_table[R_386_GOTPC]; /* These relocs are a GNU extension. */ case BFD_RELOC_386_TLS_TPOFF: TRACE ("BFD_RELOC_386_TLS_TPOFF"); return &elf_howto_table[R_386_TLS_TPOFF - R_386_ext_offset]; case BFD_RELOC_386_TLS_IE: TRACE ("BFD_RELOC_386_TLS_IE"); return &elf_howto_table[R_386_TLS_IE - R_386_ext_offset]; case BFD_RELOC_386_TLS_GOTIE: TRACE ("BFD_RELOC_386_TLS_GOTIE"); return &elf_howto_table[R_386_TLS_GOTIE - R_386_ext_offset]; case BFD_RELOC_386_TLS_LE: TRACE ("BFD_RELOC_386_TLS_LE"); return &elf_howto_table[R_386_TLS_LE - R_386_ext_offset]; case BFD_RELOC_386_TLS_GD: TRACE ("BFD_RELOC_386_TLS_GD"); return &elf_howto_table[R_386_TLS_GD - R_386_ext_offset]; case BFD_RELOC_386_TLS_LDM: TRACE ("BFD_RELOC_386_TLS_LDM"); return &elf_howto_table[R_386_TLS_LDM - R_386_ext_offset]; case BFD_RELOC_16: TRACE ("BFD_RELOC_16"); return &elf_howto_table[R_386_16 - R_386_ext_offset]; case BFD_RELOC_16_PCREL: TRACE ("BFD_RELOC_16_PCREL"); return &elf_howto_table[R_386_PC16 - R_386_ext_offset]; case BFD_RELOC_8: TRACE ("BFD_RELOC_8"); return &elf_howto_table[R_386_8 - R_386_ext_offset]; case BFD_RELOC_8_PCREL: TRACE ("BFD_RELOC_8_PCREL"); return &elf_howto_table[R_386_PC8 - R_386_ext_offset]; /* Common with Sun TLS implementation. */ case BFD_RELOC_386_TLS_LDO_32: TRACE ("BFD_RELOC_386_TLS_LDO_32"); return &elf_howto_table[R_386_TLS_LDO_32 - R_386_tls_offset]; case BFD_RELOC_386_TLS_IE_32: TRACE ("BFD_RELOC_386_TLS_IE_32"); return &elf_howto_table[R_386_TLS_IE_32 - R_386_tls_offset]; case BFD_RELOC_386_TLS_LE_32: TRACE ("BFD_RELOC_386_TLS_LE_32"); return &elf_howto_table[R_386_TLS_LE_32 - R_386_tls_offset]; case BFD_RELOC_386_TLS_DTPMOD32: TRACE ("BFD_RELOC_386_TLS_DTPMOD32"); return &elf_howto_table[R_386_TLS_DTPMOD32 - R_386_tls_offset]; case BFD_RELOC_386_TLS_DTPOFF32: TRACE ("BFD_RELOC_386_TLS_DTPOFF32"); return &elf_howto_table[R_386_TLS_DTPOFF32 - R_386_tls_offset]; case BFD_RELOC_386_TLS_TPOFF32: TRACE ("BFD_RELOC_386_TLS_TPOFF32"); return &elf_howto_table[R_386_TLS_TPOFF32 - R_386_tls_offset]; case BFD_RELOC_386_TLS_GOTDESC: TRACE ("BFD_RELOC_386_TLS_GOTDESC"); return &elf_howto_table[R_386_TLS_GOTDESC - R_386_tls_offset]; case BFD_RELOC_386_TLS_DESC_CALL: TRACE ("BFD_RELOC_386_TLS_DESC_CALL"); return &elf_howto_table[R_386_TLS_DESC_CALL - R_386_tls_offset]; case BFD_RELOC_386_TLS_DESC: TRACE ("BFD_RELOC_386_TLS_DESC"); return &elf_howto_table[R_386_TLS_DESC - R_386_tls_offset]; case BFD_RELOC_386_IRELATIVE: TRACE ("BFD_RELOC_386_IRELATIVE"); return &elf_howto_table[R_386_IRELATIVE - R_386_tls_offset]; case BFD_RELOC_VTABLE_INHERIT: TRACE ("BFD_RELOC_VTABLE_INHERIT"); return &elf_howto_table[R_386_GNU_VTINHERIT - R_386_vt_offset]; case BFD_RELOC_VTABLE_ENTRY: TRACE ("BFD_RELOC_VTABLE_ENTRY"); return &elf_howto_table[R_386_GNU_VTENTRY - R_386_vt_offset]; default: break; } TRACE ("Unknown"); return 0; } static reloc_howto_type * elf_i386_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; } static reloc_howto_type * elf_i386_rtype_to_howto (bfd *abfd, unsigned r_type) { unsigned int indx; if ((indx = r_type) >= R_386_standard && ((indx = r_type - R_386_ext_offset) - R_386_standard >= R_386_ext - R_386_standard) && ((indx = r_type - R_386_tls_offset) - R_386_ext >= R_386_irelative - R_386_ext) && ((indx = r_type - R_386_vt_offset) - R_386_irelative >= R_386_vt - R_386_irelative)) { (*_bfd_error_handler) (_("%B: invalid relocation type %d"), abfd, (int) r_type); indx = R_386_NONE; } BFD_ASSERT (elf_howto_table [indx].type == r_type); return &elf_howto_table[indx]; } static void elf_i386_info_to_howto_rel (bfd *abfd ATTRIBUTE_UNUSED, arelent *cache_ptr, Elf_Internal_Rela *dst) { unsigned int r_type = ELF32_R_TYPE (dst->r_info); cache_ptr->howto = elf_i386_rtype_to_howto (abfd, r_type); } /* Return whether a symbol name implies a local label. The UnixWare 2.1 cc generates temporary symbols that start with .X, so we recognize them here. FIXME: do other SVR4 compilers also use .X?. If so, we should move the .X recognition into _bfd_elf_is_local_label_name. */ static bfd_boolean elf_i386_is_local_label_name (bfd *abfd, const char *name) { if (name[0] == '.' && name[1] == 'X') return TRUE; return _bfd_elf_is_local_label_name (abfd, name); } /* Support for core dump NOTE sections. */ static bfd_boolean elf_i386_grok_prstatus (bfd *abfd, Elf_Internal_Note *note) { int offset; size_t size; if (note->namesz == 8 && strcmp (note->namedata, "FreeBSD") == 0) { int pr_version = bfd_get_32 (abfd, note->descdata); if (pr_version != 1) return FALSE; /* pr_cursig */ elf_tdata (abfd)->core_signal = bfd_get_32 (abfd, note->descdata + 20); /* pr_pid */ elf_tdata (abfd)->core_lwpid = bfd_get_32 (abfd, note->descdata + 24); /* pr_reg */ offset = 28; size = bfd_get_32 (abfd, note->descdata + 8); } else { switch (note->descsz) { default: return FALSE; case 144: /* Linux/i386 */ /* 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 = 68; break; } } /* Make a ".reg/999" section. */ return _bfd_elfcore_make_pseudosection (abfd, ".reg", size, note->descpos + offset); } static bfd_boolean elf_i386_grok_psinfo (bfd *abfd, Elf_Internal_Note *note) { if (note->namesz == 8 && strcmp (note->namedata, "FreeBSD") == 0) { int pr_version = bfd_get_32 (abfd, note->descdata); if (pr_version != 1) return FALSE; elf_tdata (abfd)->core_program = _bfd_elfcore_strndup (abfd, note->descdata + 8, 17); elf_tdata (abfd)->core_command = _bfd_elfcore_strndup (abfd, note->descdata + 25, 81); } else { switch (note->descsz) { default: return FALSE; case 124: /* Linux/i386 elf_prpsinfo. */ elf_tdata (abfd)->core_pid = bfd_get_32 (abfd, note->descdata + 12); elf_tdata (abfd)->core_program = _bfd_elfcore_strndup (abfd, note->descdata + 28, 16); elf_tdata (abfd)->core_command = _bfd_elfcore_strndup (abfd, note->descdata + 44, 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; } /* Functions for the i386 ELF linker. In order to gain some understanding of code in this file without knowing all the intricate details of the linker, note the following: Functions named elf_i386_* are called by external routines, other functions are only called locally. elf_i386_* functions appear in this file more or less in the order in which they are called from external routines. eg. elf_i386_check_relocs is called early in the link process, elf_i386_finish_dynamic_sections is one of the last functions. */ /* The name of the dynamic interpreter. This is put in the .interp section. */ #define ELF_DYNAMIC_INTERPRETER "/usr/lib/libc.so.1" /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid copying dynamic variables from a shared lib into an app's dynbss section, and instead use a dynamic relocation to point into the shared lib. */ #define ELIMINATE_COPY_RELOCS 1 /* The size in bytes of an entry in the procedure linkage table. */ #define PLT_ENTRY_SIZE 16 /* The first entry in an absolute procedure linkage table looks like this. See the SVR4 ABI i386 supplement to see how this works. Will be padded to PLT_ENTRY_SIZE with htab->plt0_pad_byte. */ static const bfd_byte elf_i386_plt0_entry[12] = { 0xff, 0x35, /* pushl contents of address */ 0, 0, 0, 0, /* replaced with address of .got + 4. */ 0xff, 0x25, /* jmp indirect */ 0, 0, 0, 0 /* replaced with address of .got + 8. */ }; /* Subsequent entries in an absolute procedure linkage table look like this. */ static const bfd_byte elf_i386_plt_entry[PLT_ENTRY_SIZE] = { 0xff, 0x25, /* jmp indirect */ 0, 0, 0, 0, /* replaced with address of this symbol in .got. */ 0x68, /* pushl immediate */ 0, 0, 0, 0, /* replaced with offset into relocation table. */ 0xe9, /* jmp relative */ 0, 0, 0, 0 /* replaced with offset to start of .plt. */ }; /* The first entry in a PIC procedure linkage table look like this. Will be padded to PLT_ENTRY_SIZE with htab->plt0_pad_byte. */ static const bfd_byte elf_i386_pic_plt0_entry[12] = { 0xff, 0xb3, 4, 0, 0, 0, /* pushl 4(%ebx) */ 0xff, 0xa3, 8, 0, 0, 0 /* jmp *8(%ebx) */ }; /* Subsequent entries in a PIC procedure linkage table look like this. */ static const bfd_byte elf_i386_pic_plt_entry[PLT_ENTRY_SIZE] = { 0xff, 0xa3, /* jmp *offset(%ebx) */ 0, 0, 0, 0, /* replaced with offset of this symbol in .got. */ 0x68, /* pushl immediate */ 0, 0, 0, 0, /* replaced with offset into relocation table. */ 0xe9, /* jmp relative */ 0, 0, 0, 0 /* replaced with offset to start of .plt. */ }; /* .eh_frame covering the .plt section. */ static const bfd_byte elf_i386_eh_frame_plt[] = { #define PLT_CIE_LENGTH 20 #define PLT_FDE_LENGTH 36 #define PLT_FDE_START_OFFSET 4 + PLT_CIE_LENGTH + 8 #define PLT_FDE_LEN_OFFSET 4 + PLT_CIE_LENGTH + 12 PLT_CIE_LENGTH, 0, 0, 0, /* CIE length */ 0, 0, 0, 0, /* CIE ID */ 1, /* CIE version */ 'z', 'R', 0, /* Augmentation string */ 1, /* Code alignment factor */ 0x7c, /* Data alignment factor */ 8, /* Return address column */ 1, /* Augmentation size */ DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding */ DW_CFA_def_cfa, 4, 4, /* DW_CFA_def_cfa: r4 (esp) ofs 4 */ DW_CFA_offset + 8, 1, /* DW_CFA_offset: r8 (eip) at cfa-4 */ DW_CFA_nop, DW_CFA_nop, PLT_FDE_LENGTH, 0, 0, 0, /* FDE length */ PLT_CIE_LENGTH + 8, 0, 0, 0, /* CIE pointer */ 0, 0, 0, 0, /* R_386_PC32 .plt goes here */ 0, 0, 0, 0, /* .plt size goes here */ 0, /* Augmentation size */ DW_CFA_def_cfa_offset, 8, /* DW_CFA_def_cfa_offset: 8 */ DW_CFA_advance_loc + 6, /* DW_CFA_advance_loc: 6 to __PLT__+6 */ DW_CFA_def_cfa_offset, 12, /* DW_CFA_def_cfa_offset: 12 */ DW_CFA_advance_loc + 10, /* DW_CFA_advance_loc: 10 to __PLT__+16 */ DW_CFA_def_cfa_expression, /* DW_CFA_def_cfa_expression */ 11, /* Block length */ DW_OP_breg4, 4, /* DW_OP_breg4 (esp): 4 */ DW_OP_breg8, 0, /* DW_OP_breg8 (eip): 0 */ DW_OP_lit15, DW_OP_and, DW_OP_lit11, DW_OP_ge, DW_OP_lit2, DW_OP_shl, DW_OP_plus, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop }; struct elf_i386_plt_layout { /* The first entry in an absolute procedure linkage table looks like this. */ const bfd_byte *plt0_entry; unsigned int plt0_entry_size; /* Offsets into plt0_entry that are to be replaced with GOT[1] and GOT[2]. */ unsigned int plt0_got1_offset; unsigned int plt0_got2_offset; /* Later entries in an absolute procedure linkage table look like this. */ const bfd_byte *plt_entry; unsigned int plt_entry_size; /* Offsets into plt_entry that are to be replaced with... */ unsigned int plt_got_offset; /* ... address of this symbol in .got. */ unsigned int plt_reloc_offset; /* ... offset into relocation table. */ unsigned int plt_plt_offset; /* ... offset to start of .plt. */ /* Offset into plt_entry where the initial value of the GOT entry points. */ unsigned int plt_lazy_offset; /* The first entry in a PIC procedure linkage table looks like this. */ const bfd_byte *pic_plt0_entry; /* Subsequent entries in a PIC procedure linkage table look like this. */ const bfd_byte *pic_plt_entry; /* .eh_frame covering the .plt section. */ const bfd_byte *eh_frame_plt; unsigned int eh_frame_plt_size; }; #define GET_PLT_ENTRY_SIZE(abfd) \ get_elf_i386_backend_data (abfd)->plt->plt_entry_size /* These are the standard parameters. */ static const struct elf_i386_plt_layout elf_i386_plt = { elf_i386_plt0_entry, /* plt0_entry */ sizeof (elf_i386_plt0_entry), /* plt0_entry_size */ 2, /* plt0_got1_offset */ 8, /* plt0_got2_offset */ elf_i386_plt_entry, /* plt_entry */ PLT_ENTRY_SIZE, /* plt_entry_size */ 2, /* plt_got_offset */ 7, /* plt_reloc_offset */ 12, /* plt_plt_offset */ 6, /* plt_lazy_offset */ elf_i386_pic_plt0_entry, /* pic_plt0_entry */ elf_i386_pic_plt_entry, /* pic_plt_entry */ elf_i386_eh_frame_plt, /* eh_frame_plt */ sizeof (elf_i386_eh_frame_plt), /* eh_frame_plt_size */ }; /* On VxWorks, the .rel.plt.unloaded section has absolute relocations for the PLTResolve stub and then for each PLT entry. */ #define PLTRESOLVE_RELOCS_SHLIB 0 #define PLTRESOLVE_RELOCS 2 #define PLT_NON_JUMP_SLOT_RELOCS 2 /* Architecture-specific backend data for i386. */ struct elf_i386_backend_data { /* Parameters describing PLT generation. */ const struct elf_i386_plt_layout *plt; /* Value used to fill the unused bytes of the first PLT entry. */ bfd_byte plt0_pad_byte; /* True if the target system is VxWorks. */ int is_vxworks; }; #define get_elf_i386_backend_data(abfd) \ ((const struct elf_i386_backend_data *) \ get_elf_backend_data (abfd)->arch_data) /* These are the standard parameters. */ static const struct elf_i386_backend_data elf_i386_arch_bed = { &elf_i386_plt, /* plt */ 0, /* plt0_pad_byte */ 0, /* is_vxworks */ }; #define elf_backend_arch_data &elf_i386_arch_bed /* i386 ELF linker hash entry. */ struct elf_i386_link_hash_entry { struct elf_link_hash_entry elf; /* Track dynamic relocs copied for this symbol. */ struct elf_dyn_relocs *dyn_relocs; #define GOT_UNKNOWN 0 #define GOT_NORMAL 1 #define GOT_TLS_GD 2 #define GOT_TLS_IE 4 #define GOT_TLS_IE_POS 5 #define GOT_TLS_IE_NEG 6 #define GOT_TLS_IE_BOTH 7 #define GOT_TLS_GDESC 8 #define GOT_TLS_GD_BOTH_P(type) \ ((type) == (GOT_TLS_GD | GOT_TLS_GDESC)) #define GOT_TLS_GD_P(type) \ ((type) == GOT_TLS_GD || GOT_TLS_GD_BOTH_P (type)) #define GOT_TLS_GDESC_P(type) \ ((type) == GOT_TLS_GDESC || GOT_TLS_GD_BOTH_P (type)) #define GOT_TLS_GD_ANY_P(type) \ (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type)) unsigned char tls_type; /* Offset of the GOTPLT entry reserved for the TLS descriptor, starting at the end of the jump table. */ bfd_vma tlsdesc_got; }; #define elf_i386_hash_entry(ent) ((struct elf_i386_link_hash_entry *)(ent)) struct elf_i386_obj_tdata { struct elf_obj_tdata root; /* tls_type for each local got entry. */ char *local_got_tls_type; /* GOTPLT entries for TLS descriptors. */ bfd_vma *local_tlsdesc_gotent; }; #define elf_i386_tdata(abfd) \ ((struct elf_i386_obj_tdata *) (abfd)->tdata.any) #define elf_i386_local_got_tls_type(abfd) \ (elf_i386_tdata (abfd)->local_got_tls_type) #define elf_i386_local_tlsdesc_gotent(abfd) \ (elf_i386_tdata (abfd)->local_tlsdesc_gotent) #define is_i386_elf(bfd) \ (bfd_get_flavour (bfd) == bfd_target_elf_flavour \ && elf_tdata (bfd) != NULL \ && elf_object_id (bfd) == I386_ELF_DATA) static bfd_boolean elf_i386_mkobject (bfd *abfd) { return bfd_elf_allocate_object (abfd, sizeof (struct elf_i386_obj_tdata), I386_ELF_DATA); } /* i386 ELF linker hash table. */ struct elf_i386_link_hash_table { struct elf_link_hash_table elf; /* Short-cuts to get to dynamic linker sections. */ asection *sdynbss; asection *srelbss; asection *plt_eh_frame; union { bfd_signed_vma refcount; bfd_vma offset; } tls_ldm_got; /* The amount of space used by the reserved portion of the sgotplt section, plus whatever space is used by the jump slots. */ bfd_vma sgotplt_jump_table_size; /* Small local sym cache. */ struct sym_cache sym_cache; /* _TLS_MODULE_BASE_ symbol. */ struct bfd_link_hash_entry *tls_module_base; /* Used by local STT_GNU_IFUNC symbols. */ htab_t loc_hash_table; void * loc_hash_memory; /* The (unloaded but important) .rel.plt.unloaded section on VxWorks. */ asection *srelplt2; /* The index of the next unused R_386_TLS_DESC slot in .rel.plt. */ bfd_vma next_tls_desc_index; /* The index of the next unused R_386_JUMP_SLOT slot in .rel.plt. */ bfd_vma next_jump_slot_index; /* The index of the next unused R_386_IRELATIVE slot in .rel.plt. */ bfd_vma next_irelative_index; }; /* Get the i386 ELF linker hash table from a link_info structure. */ #define elf_i386_hash_table(p) \ (elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) \ == I386_ELF_DATA ? ((struct elf_i386_link_hash_table *) ((p)->hash)) : NULL) #define elf_i386_compute_jump_table_size(htab) \ ((htab)->next_tls_desc_index * 4) /* Create an entry in an i386 ELF linker hash table. */ static struct bfd_hash_entry * elf_i386_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 = (struct bfd_hash_entry *) bfd_hash_allocate (table, sizeof (struct elf_i386_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_i386_link_hash_entry *eh; eh = (struct elf_i386_link_hash_entry *) entry; eh->dyn_relocs = NULL; eh->tls_type = GOT_UNKNOWN; eh->tlsdesc_got = (bfd_vma) -1; } return entry; } /* Compute a hash of a local hash entry. We use elf_link_hash_entry for local symbol so that we can handle local STT_GNU_IFUNC symbols as global symbol. We reuse indx and dynstr_index for local symbol hash since they aren't used by global symbols in this backend. */ static hashval_t elf_i386_local_htab_hash (const void *ptr) { struct elf_link_hash_entry *h = (struct elf_link_hash_entry *) ptr; return ELF_LOCAL_SYMBOL_HASH (h->indx, h->dynstr_index); } /* Compare local hash entries. */ static int elf_i386_local_htab_eq (const void *ptr1, const void *ptr2) { struct elf_link_hash_entry *h1 = (struct elf_link_hash_entry *) ptr1; struct elf_link_hash_entry *h2 = (struct elf_link_hash_entry *) ptr2; return h1->indx == h2->indx && h1->dynstr_index == h2->dynstr_index; } /* Find and/or create a hash entry for local symbol. */ static struct elf_link_hash_entry * elf_i386_get_local_sym_hash (struct elf_i386_link_hash_table *htab, bfd *abfd, const Elf_Internal_Rela *rel, bfd_boolean create) { struct elf_i386_link_hash_entry e, *ret; asection *sec = abfd->sections; hashval_t h = ELF_LOCAL_SYMBOL_HASH (sec->id, ELF32_R_SYM (rel->r_info)); void **slot; e.elf.indx = sec->id; e.elf.dynstr_index = ELF32_R_SYM (rel->r_info); slot = htab_find_slot_with_hash (htab->loc_hash_table, &e, h, create ? INSERT : NO_INSERT); if (!slot) return NULL; if (*slot) { ret = (struct elf_i386_link_hash_entry *) *slot; return &ret->elf; } ret = (struct elf_i386_link_hash_entry *) objalloc_alloc ((struct objalloc *) htab->loc_hash_memory, sizeof (struct elf_i386_link_hash_entry)); if (ret) { memset (ret, 0, sizeof (*ret)); ret->elf.indx = sec->id; ret->elf.dynstr_index = ELF32_R_SYM (rel->r_info); ret->elf.dynindx = -1; *slot = ret; } return &ret->elf; } /* Create an i386 ELF linker hash table. */ static struct bfd_link_hash_table * elf_i386_link_hash_table_create (bfd *abfd) { struct elf_i386_link_hash_table *ret; bfd_size_type amt = sizeof (struct elf_i386_link_hash_table); ret = (struct elf_i386_link_hash_table *) bfd_malloc (amt); if (ret == NULL) return NULL; if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd, elf_i386_link_hash_newfunc, sizeof (struct elf_i386_link_hash_entry), I386_ELF_DATA)) { free (ret); return NULL; } ret->sdynbss = NULL; ret->srelbss = NULL; ret->plt_eh_frame = NULL; ret->tls_ldm_got.refcount = 0; ret->next_tls_desc_index = 0; ret->sgotplt_jump_table_size = 0; ret->sym_cache.abfd = NULL; ret->srelplt2 = NULL; ret->tls_module_base = NULL; ret->next_jump_slot_index = 0; ret->next_irelative_index = 0; ret->loc_hash_table = htab_try_create (1024, elf_i386_local_htab_hash, elf_i386_local_htab_eq, NULL); ret->loc_hash_memory = objalloc_create (); if (!ret->loc_hash_table || !ret->loc_hash_memory) { free (ret); return NULL; } return &ret->elf.root; } /* Destroy an i386 ELF linker hash table. */ static void elf_i386_link_hash_table_free (struct bfd_link_hash_table *hash) { struct elf_i386_link_hash_table *htab = (struct elf_i386_link_hash_table *) hash; if (htab->loc_hash_table) htab_delete (htab->loc_hash_table); if (htab->loc_hash_memory) objalloc_free ((struct objalloc *) htab->loc_hash_memory); _bfd_generic_link_hash_table_free (hash); } /* Create .plt, .rel.plt, .got, .got.plt, .rel.got, .dynbss, and .rel.bss sections in DYNOBJ, and set up shortcuts to them in our hash table. */ static bfd_boolean elf_i386_create_dynamic_sections (bfd *dynobj, struct bfd_link_info *info) { struct elf_i386_link_hash_table *htab; if (!_bfd_elf_create_dynamic_sections (dynobj, info)) return FALSE; htab = elf_i386_hash_table (info); if (htab == NULL) return FALSE; htab->sdynbss = bfd_get_section_by_name (dynobj, ".dynbss"); if (!info->shared) htab->srelbss = bfd_get_section_by_name (dynobj, ".rel.bss"); if (!htab->sdynbss || (!info->shared && !htab->srelbss)) abort (); if (get_elf_i386_backend_data (dynobj)->is_vxworks && !elf_vxworks_create_dynamic_sections (dynobj, info, &htab->srelplt2)) return FALSE; if (!info->no_ld_generated_unwind_info && bfd_get_section_by_name (dynobj, ".eh_frame") == NULL && htab->elf.splt != NULL) { flagword flags = get_elf_backend_data (dynobj)->dynamic_sec_flags; htab->plt_eh_frame = bfd_make_section_with_flags (dynobj, ".eh_frame", flags | SEC_READONLY); if (htab->plt_eh_frame == NULL || !bfd_set_section_alignment (dynobj, htab->plt_eh_frame, 2)) return FALSE; htab->plt_eh_frame->size = sizeof (elf_i386_eh_frame_plt); htab->plt_eh_frame->contents = bfd_alloc (dynobj, htab->plt_eh_frame->size); memcpy (htab->plt_eh_frame->contents, elf_i386_eh_frame_plt, sizeof (elf_i386_eh_frame_plt)); } return TRUE; } /* Copy the extra info we tack onto an elf_link_hash_entry. */ static void elf_i386_copy_indirect_symbol (struct bfd_link_info *info, struct elf_link_hash_entry *dir, struct elf_link_hash_entry *ind) { struct elf_i386_link_hash_entry *edir, *eind; edir = (struct elf_i386_link_hash_entry *) dir; eind = (struct elf_i386_link_hash_entry *) ind; if (eind->dyn_relocs != NULL) { if (edir->dyn_relocs != NULL) { struct elf_dyn_relocs **pp; struct elf_dyn_relocs *p; /* Add reloc counts against the indirect sym to the direct sym list. Merge any entries against the same section. */ for (pp = &eind->dyn_relocs; (p = *pp) != NULL; ) { struct elf_dyn_relocs *q; for (q = edir->dyn_relocs; q != NULL; q = q->next) if (q->sec == p->sec) { q->pc_count += p->pc_count; q->count += p->count; *pp = p->next; break; } if (q == NULL) pp = &p->next; } *pp = edir->dyn_relocs; } edir->dyn_relocs = eind->dyn_relocs; eind->dyn_relocs = NULL; } if (ind->root.type == bfd_link_hash_indirect && dir->got.refcount <= 0) { edir->tls_type = eind->tls_type; eind->tls_type = GOT_UNKNOWN; } if (ELIMINATE_COPY_RELOCS && ind->root.type != bfd_link_hash_indirect && dir->dynamic_adjusted) { /* If called to transfer flags for a weakdef during processing of elf_adjust_dynamic_symbol, don't copy non_got_ref. We clear it ourselves for ELIMINATE_COPY_RELOCS. */ dir->ref_dynamic |= ind->ref_dynamic; dir->ref_regular |= ind->ref_regular; dir->ref_regular_nonweak |= ind->ref_regular_nonweak; dir->needs_plt |= ind->needs_plt; dir->pointer_equality_needed |= ind->pointer_equality_needed; } else _bfd_elf_link_hash_copy_indirect (info, dir, ind); } /* Return TRUE if the TLS access code sequence support transition from R_TYPE. */ static bfd_boolean elf_i386_check_tls_transition (bfd *abfd, asection *sec, bfd_byte *contents, Elf_Internal_Shdr *symtab_hdr, struct elf_link_hash_entry **sym_hashes, unsigned int r_type, const Elf_Internal_Rela *rel, const Elf_Internal_Rela *relend) { unsigned int val, type; unsigned long r_symndx; struct elf_link_hash_entry *h; bfd_vma offset; /* Get the section contents. */ if (contents == NULL) { if (elf_section_data (sec)->this_hdr.contents != NULL) contents = elf_section_data (sec)->this_hdr.contents; else { /* FIXME: How to better handle error condition? */ if (!bfd_malloc_and_get_section (abfd, sec, &contents)) return FALSE; /* Cache the section contents for elf_link_input_bfd. */ elf_section_data (sec)->this_hdr.contents = contents; } } offset = rel->r_offset; switch (r_type) { case R_386_TLS_GD: case R_386_TLS_LDM: if (offset < 2 || (rel + 1) >= relend) return FALSE; type = bfd_get_8 (abfd, contents + offset - 2); if (r_type == R_386_TLS_GD) { /* Check transition from GD access model. Only leal foo@tlsgd(,%reg,1), %eax; call ___tls_get_addr leal foo@tlsgd(%reg), %eax; call ___tls_get_addr; nop can transit to different access model. */ if ((offset + 10) > sec->size || (type != 0x8d && type != 0x04)) return FALSE; val = bfd_get_8 (abfd, contents + offset - 1); if (type == 0x04) { /* leal foo@tlsgd(,%reg,1), %eax; call ___tls_get_addr */ if (offset < 3) return FALSE; if (bfd_get_8 (abfd, contents + offset - 3) != 0x8d) return FALSE; if ((val & 0xc7) != 0x05 || val == (4 << 3)) return FALSE; } else { /* leal foo@tlsgd(%reg), %eax; call ___tls_get_addr; nop */ if ((val & 0xf8) != 0x80 || (val & 7) == 4) return FALSE; if (bfd_get_8 (abfd, contents + offset + 9) != 0x90) return FALSE; } } else { /* Check transition from LD access model. Only leal foo@tlsgd(%reg), %eax; call ___tls_get_addr can transit to different access model. */ if (type != 0x8d || (offset + 9) > sec->size) return FALSE; val = bfd_get_8 (abfd, contents + offset - 1); if ((val & 0xf8) != 0x80 || (val & 7) == 4) return FALSE; } if (bfd_get_8 (abfd, contents + offset + 4) != 0xe8) return FALSE; r_symndx = ELF32_R_SYM (rel[1].r_info); if (r_symndx < symtab_hdr->sh_info) return FALSE; h = sym_hashes[r_symndx - symtab_hdr->sh_info]; /* Use strncmp to check ___tls_get_addr since ___tls_get_addr may be versioned. */ return (h != NULL && h->root.root.string != NULL && (ELF32_R_TYPE (rel[1].r_info) == R_386_PC32 || ELF32_R_TYPE (rel[1].r_info) == R_386_PLT32) && (strncmp (h->root.root.string, "___tls_get_addr", 15) == 0)); case R_386_TLS_IE: /* Check transition from IE access model: movl foo@indntpoff(%rip), %eax movl foo@indntpoff(%rip), %reg addl foo@indntpoff(%rip), %reg */ if (offset < 1 || (offset + 4) > sec->size) return FALSE; /* Check "movl foo@tpoff(%rip), %eax" first. */ val = bfd_get_8 (abfd, contents + offset - 1); if (val == 0xa1) return TRUE; if (offset < 2) return FALSE; /* Check movl|addl foo@tpoff(%rip), %reg. */ type = bfd_get_8 (abfd, contents + offset - 2); return ((type == 0x8b || type == 0x03) && (val & 0xc7) == 0x05); case R_386_TLS_GOTIE: case R_386_TLS_IE_32: /* Check transition from {IE_32,GOTIE} access model: subl foo@{tpoff,gontoff}(%reg1), %reg2 movl foo@{tpoff,gontoff}(%reg1), %reg2 addl foo@{tpoff,gontoff}(%reg1), %reg2 */ if (offset < 2 || (offset + 4) > sec->size) return FALSE; val = bfd_get_8 (abfd, contents + offset - 1); if ((val & 0xc0) != 0x80 || (val & 7) == 4) return FALSE; type = bfd_get_8 (abfd, contents + offset - 2); return type == 0x8b || type == 0x2b || type == 0x03; case R_386_TLS_GOTDESC: /* Check transition from GDesc access model: leal x@tlsdesc(%ebx), %eax Make sure it's a leal adding ebx to a 32-bit offset into any register, although it's probably almost always going to be eax. */ if (offset < 2 || (offset + 4) > sec->size) return FALSE; if (bfd_get_8 (abfd, contents + offset - 2) != 0x8d) return FALSE; val = bfd_get_8 (abfd, contents + offset - 1); return (val & 0xc7) == 0x83; case R_386_TLS_DESC_CALL: /* Check transition from GDesc access model: call *x@tlsdesc(%rax) */ if (offset + 2 <= sec->size) { /* Make sure that it's a call *x@tlsdesc(%rax). */ static const unsigned char call[] = { 0xff, 0x10 }; return memcmp (contents + offset, call, 2) == 0; } return FALSE; default: abort (); } } /* Return TRUE if the TLS access transition is OK or no transition will be performed. Update R_TYPE if there is a transition. */ static bfd_boolean elf_i386_tls_transition (struct bfd_link_info *info, bfd *abfd, asection *sec, bfd_byte *contents, Elf_Internal_Shdr *symtab_hdr, struct elf_link_hash_entry **sym_hashes, unsigned int *r_type, int tls_type, const Elf_Internal_Rela *rel, const Elf_Internal_Rela *relend, struct elf_link_hash_entry *h, unsigned long r_symndx) { unsigned int from_type = *r_type; unsigned int to_type = from_type; bfd_boolean check = TRUE; /* Skip TLS transition for functions. */ if (h != NULL && (h->type == STT_FUNC || h->type == STT_GNU_IFUNC)) return TRUE; switch (from_type) { case R_386_TLS_GD: case R_386_TLS_GOTDESC: case R_386_TLS_DESC_CALL: case R_386_TLS_IE_32: case R_386_TLS_IE: case R_386_TLS_GOTIE: if (info->executable) { if (h == NULL) to_type = R_386_TLS_LE_32; else if (from_type != R_386_TLS_IE && from_type != R_386_TLS_GOTIE) to_type = R_386_TLS_IE_32; } /* When we are called from elf_i386_relocate_section, CONTENTS isn't NULL and there may be additional transitions based on TLS_TYPE. */ if (contents != NULL) { unsigned int new_to_type = to_type; if (info->executable && h != NULL && h->dynindx == -1 && (tls_type & GOT_TLS_IE)) new_to_type = R_386_TLS_LE_32; if (to_type == R_386_TLS_GD || to_type == R_386_TLS_GOTDESC || to_type == R_386_TLS_DESC_CALL) { if (tls_type == GOT_TLS_IE_POS) new_to_type = R_386_TLS_GOTIE; else if (tls_type & GOT_TLS_IE) new_to_type = R_386_TLS_IE_32; } /* We checked the transition before when we were called from elf_i386_check_relocs. We only want to check the new transition which hasn't been checked before. */ check = new_to_type != to_type && from_type == to_type; to_type = new_to_type; } break; case R_386_TLS_LDM: if (info->executable) to_type = R_386_TLS_LE_32; break; default: return TRUE; } /* Return TRUE if there is no transition. */ if (from_type == to_type) return TRUE; /* Check if the transition can be performed. */ if (check && ! elf_i386_check_tls_transition (abfd, sec, contents, symtab_hdr, sym_hashes, from_type, rel, relend)) { reloc_howto_type *from, *to; const char *name; from = elf_i386_rtype_to_howto (abfd, from_type); to = elf_i386_rtype_to_howto (abfd, to_type); if (h) name = h->root.root.string; else { struct elf_i386_link_hash_table *htab; htab = elf_i386_hash_table (info); if (htab == NULL) name = "*unknown*"; else { Elf_Internal_Sym *isym; isym = bfd_sym_from_r_symndx (&htab->sym_cache, abfd, r_symndx); name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL); } } (*_bfd_error_handler) (_("%B: TLS transition from %s to %s against `%s' at 0x%lx " "in section `%A' failed"), abfd, sec, from->name, to->name, name, (unsigned long) rel->r_offset); bfd_set_error (bfd_error_bad_value); return FALSE; } *r_type = to_type; return TRUE; } /* Look through the relocs for a section during the first phase, and calculate needed space in the global offset table, procedure linkage table, and dynamic reloc sections. */ static bfd_boolean elf_i386_check_relocs (bfd *abfd, struct bfd_link_info *info, asection *sec, const Elf_Internal_Rela *relocs) { struct elf_i386_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; asection *sreloc; if (info->relocatable) return TRUE; BFD_ASSERT (is_i386_elf (abfd)); htab = elf_i386_hash_table (info); if (htab == NULL) return FALSE; symtab_hdr = &elf_symtab_hdr (abfd); sym_hashes = elf_sym_hashes (abfd); sreloc = NULL; 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; Elf_Internal_Sym *isym; const char *name; 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) { /* A local symbol. */ isym = bfd_sym_from_r_symndx (&htab->sym_cache, abfd, r_symndx); if (isym == NULL) return FALSE; /* Check relocation against local STT_GNU_IFUNC symbol. */ if (ELF32_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) { h = elf_i386_get_local_sym_hash (htab, abfd, rel, TRUE); if (h == NULL) return FALSE; /* Fake a STT_GNU_IFUNC symbol. */ h->type = STT_GNU_IFUNC; h->def_regular = 1; h->ref_regular = 1; h->forced_local = 1; h->root.type = bfd_link_hash_defined; } else h = NULL; } else { isym = NULL; 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; } if (h != NULL) { /* Create the ifunc sections for static executables. If we never see an indirect function symbol nor we are building a static executable, those sections will be empty and won't appear in output. */ switch (r_type) { default: break; case R_386_32: case R_386_PC32: case R_386_PLT32: case R_386_GOT32: case R_386_GOTOFF: if (htab->elf.dynobj == NULL) htab->elf.dynobj = abfd; if (!_bfd_elf_create_ifunc_sections (htab->elf.dynobj, info)) return FALSE; break; } /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it here if it is defined in a non-shared object. */ if (h->type == STT_GNU_IFUNC && h->def_regular) { /* It is referenced by a non-shared object. */ h->ref_regular = 1; h->needs_plt = 1; /* STT_GNU_IFUNC symbol must go through PLT. */ h->plt.refcount += 1; /* STT_GNU_IFUNC needs dynamic sections. */ if (htab->elf.dynobj == NULL) htab->elf.dynobj = abfd; switch (r_type) { default: if (h->root.root.string) name = h->root.root.string; else name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL); (*_bfd_error_handler) (_("%B: relocation %s against STT_GNU_IFUNC " "symbol `%s' isn't handled by %s"), abfd, elf_howto_table[r_type].name, name, __FUNCTION__); bfd_set_error (bfd_error_bad_value); return FALSE; case R_386_32: h->non_got_ref = 1; h->pointer_equality_needed = 1; if (info->shared) { /* We must copy these reloc types into the output file. Create a reloc section in dynobj and make room for this reloc. */ sreloc = _bfd_elf_create_ifunc_dyn_reloc (abfd, info, sec, sreloc, &((struct elf_i386_link_hash_entry *) h)->dyn_relocs); if (sreloc == NULL) return FALSE; } break; case R_386_PC32: h->non_got_ref = 1; break; case R_386_PLT32: break; case R_386_GOT32: case R_386_GOTOFF: h->got.refcount += 1; if (htab->elf.sgot == NULL && !_bfd_elf_create_got_section (htab->elf.dynobj, info)) return FALSE; break; } continue; } } if (! elf_i386_tls_transition (info, abfd, sec, NULL, symtab_hdr, sym_hashes, &r_type, GOT_UNKNOWN, rel, rel_end, h, r_symndx)) return FALSE; switch (r_type) { case R_386_TLS_LDM: htab->tls_ldm_got.refcount += 1; goto create_got; case R_386_PLT32: /* This symbol requires a procedure linkage table entry. We actually build the entry in adjust_dynamic_symbol, because this might be a case of linking PIC code which is never referenced by a dynamic object, in which case we don't need to generate a procedure linkage table entry after all. */ /* If this is a local symbol, we resolve it directly without creating a procedure linkage table entry. */ if (h == NULL) continue; h->needs_plt = 1; h->plt.refcount += 1; break; case R_386_TLS_IE_32: case R_386_TLS_IE: case R_386_TLS_GOTIE: if (!info->executable) info->flags |= DF_STATIC_TLS; /* Fall through */ case R_386_GOT32: case R_386_TLS_GD: case R_386_TLS_GOTDESC: case R_386_TLS_DESC_CALL: /* This symbol requires a global offset table entry. */ { int tls_type, old_tls_type; switch (r_type) { default: case R_386_GOT32: tls_type = GOT_NORMAL; break; case R_386_TLS_GD: tls_type = GOT_TLS_GD; break; case R_386_TLS_GOTDESC: case R_386_TLS_DESC_CALL: tls_type = GOT_TLS_GDESC; break; case R_386_TLS_IE_32: if (ELF32_R_TYPE (rel->r_info) == r_type) tls_type = GOT_TLS_IE_NEG; else /* If this is a GD->IE transition, we may use either of R_386_TLS_TPOFF and R_386_TLS_TPOFF32. */ tls_type = GOT_TLS_IE; break; case R_386_TLS_IE: case R_386_TLS_GOTIE: tls_type = GOT_TLS_IE_POS; break; } if (h != NULL) { h->got.refcount += 1; old_tls_type = elf_i386_hash_entry(h)->tls_type; } else { bfd_signed_vma *local_got_refcounts; /* This is a global offset table entry for a local symbol. */ local_got_refcounts = elf_local_got_refcounts (abfd); if (local_got_refcounts == NULL) { bfd_size_type size; size = symtab_hdr->sh_info; size *= (sizeof (bfd_signed_vma) + sizeof (bfd_vma) + sizeof(char)); local_got_refcounts = (bfd_signed_vma *) bfd_zalloc (abfd, size); if (local_got_refcounts == NULL) return FALSE; elf_local_got_refcounts (abfd) = local_got_refcounts; elf_i386_local_tlsdesc_gotent (abfd) = (bfd_vma *) (local_got_refcounts + symtab_hdr->sh_info); elf_i386_local_got_tls_type (abfd) = (char *) (local_got_refcounts + 2 * symtab_hdr->sh_info); } local_got_refcounts[r_symndx] += 1; old_tls_type = elf_i386_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 dynamic model for it. */ else if (old_tls_type != tls_type && old_tls_type != GOT_UNKNOWN && (! GOT_TLS_GD_ANY_P (old_tls_type) || (tls_type & GOT_TLS_IE) == 0)) { if ((old_tls_type & GOT_TLS_IE) && GOT_TLS_GD_ANY_P (tls_type)) tls_type = old_tls_type; else if (GOT_TLS_GD_ANY_P (old_tls_type) && GOT_TLS_GD_ANY_P (tls_type)) tls_type |= old_tls_type; else { if (h) name = h->root.root.string; else name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL); (*_bfd_error_handler) (_("%B: `%s' accessed both as normal and " "thread local symbol"), abfd, name); return FALSE; } } if (old_tls_type != tls_type) { if (h != NULL) elf_i386_hash_entry (h)->tls_type = tls_type; else elf_i386_local_got_tls_type (abfd) [r_symndx] = tls_type; } } /* Fall through */ case R_386_GOTOFF: case R_386_GOTPC: create_got: if (htab->elf.sgot == NULL) { if (htab->elf.dynobj == NULL) htab->elf.dynobj = abfd; if (!_bfd_elf_create_got_section (htab->elf.dynobj, info)) return FALSE; } if (r_type != R_386_TLS_IE) break; /* Fall through */ case R_386_TLS_LE_32: case R_386_TLS_LE: if (info->executable) break; info->flags |= DF_STATIC_TLS; /* Fall through */ case R_386_32: case R_386_PC32: if (h != NULL && info->executable) { /* If this reloc is in a read-only section, we might need a copy reloc. We can't check reliably at this stage whether the section is read-only, as input sections have not yet been mapped to output sections. Tentatively set the flag for now, and correct in adjust_dynamic_symbol. */ h->non_got_ref = 1; /* We may need a .plt entry if the function this reloc refers to is in a shared lib. */ h->plt.refcount += 1; if (r_type != R_386_PC32) h->pointer_equality_needed = 1; } /* If we are creating a shared library, and this is a reloc against a global symbol, or a non PC relative reloc against a local symbol, then we need to copy the reloc into the shared library. However, if we are linking with -Bsymbolic, we do not need to copy a reloc against a global symbol which is defined in an object we are including in the link (i.e., DEF_REGULAR is set). At this point we have not seen all the input files, so it is possible that DEF_REGULAR is not set now but will be set later (it is never cleared). In case of a weak definition, DEF_REGULAR may be cleared later by a strong definition in a shared library. We account for that possibility below by storing information in the relocs_copied field of the hash table entry. A similar situation occurs when creating shared libraries and symbol visibility changes render the symbol local. If on the other hand, we are creating an executable, we may need to keep relocations for symbols satisfied by a dynamic library if we manage to avoid copy relocs for the symbol. */ if ((info->shared && (sec->flags & SEC_ALLOC) != 0 && (r_type != R_386_PC32 || (h != NULL && (! SYMBOLIC_BIND (info, h) || h->root.type == bfd_link_hash_defweak || !h->def_regular)))) || (ELIMINATE_COPY_RELOCS && !info->shared && (sec->flags & SEC_ALLOC) != 0 && h != NULL && (h->root.type == bfd_link_hash_defweak || !h->def_regular))) { struct elf_dyn_relocs *p; struct elf_dyn_relocs **head; /* We must copy these reloc types into the output file. Create a reloc section in dynobj and make room for this reloc. */ if (sreloc == NULL) { if (htab->elf.dynobj == NULL) htab->elf.dynobj = abfd; sreloc = _bfd_elf_make_dynamic_reloc_section (sec, htab->elf.dynobj, 2, abfd, /*rela?*/ FALSE); if (sreloc == NULL) return FALSE; } /* If this is a global symbol, we count the number of relocations we need for this symbol. */ if (h != NULL) { head = &((struct elf_i386_link_hash_entry *) h)->dyn_relocs; } else { /* Track dynamic relocs needed for local syms too. We really need local syms available to do this easily. Oh well. */ void **vpp; asection *s; isym = bfd_sym_from_r_symndx (&htab->sym_cache, abfd, r_symndx); if (isym == NULL) return FALSE; s = bfd_section_from_elf_index (abfd, isym->st_shndx); if (s == NULL) s = sec; vpp = &elf_section_data (s)->local_dynrel; head = (struct elf_dyn_relocs **)vpp; } p = *head; if (p == NULL || p->sec != sec) { bfd_size_type amt = sizeof *p; p = (struct elf_dyn_relocs *) bfd_alloc (htab->elf.dynobj, amt); if (p == NULL) return FALSE; p->next = *head; *head = p; p->sec = sec; p->count = 0; p->pc_count = 0; } p->count += 1; if (r_type == R_386_PC32) p->pc_count += 1; } break; /* This relocation describes the C++ object vtable hierarchy. Reconstruct it for later use during GC. */ case R_386_GNU_VTINHERIT: if (!bfd_elf_gc_record_vtinherit (abfd, sec, h, rel->r_offset)) return FALSE; break; /* This relocation describes which C++ vtable entries are actually used. Record for later use during GC. */ case R_386_GNU_VTENTRY: BFD_ASSERT (h != NULL); if (h != NULL && !bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_offset)) return FALSE; break; default: break; } } return TRUE; } /* Return the section that should be marked against GC for a given relocation. */ static asection * elf_i386_gc_mark_hook (asection *sec, struct bfd_link_info *info, Elf_Internal_Rela *rel, struct elf_link_hash_entry *h, Elf_Internal_Sym *sym) { if (h != NULL) switch (ELF32_R_TYPE (rel->r_info)) { case R_386_GNU_VTINHERIT: case R_386_GNU_VTENTRY: return NULL; } return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym); } /* Update the got entry reference counts for the section being removed. */ static bfd_boolean elf_i386_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info, asection *sec, const Elf_Internal_Rela *relocs) { struct elf_i386_link_hash_table *htab; Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes; bfd_signed_vma *local_got_refcounts; const Elf_Internal_Rela *rel, *relend; if (info->relocatable) return TRUE; htab = elf_i386_hash_table (info); if (htab == NULL) return FALSE; elf_section_data (sec)->local_dynrel = NULL; symtab_hdr = &elf_symtab_hdr (abfd); sym_hashes = elf_sym_hashes (abfd); local_got_refcounts = elf_local_got_refcounts (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; 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; } else { /* A local symbol. */ Elf_Internal_Sym *isym; isym = bfd_sym_from_r_symndx (&htab->sym_cache, abfd, r_symndx); /* Check relocation against local STT_GNU_IFUNC symbol. */ if (isym != NULL && ELF32_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) { h = elf_i386_get_local_sym_hash (htab, abfd, rel, FALSE); if (h == NULL) abort (); } } if (h) { struct elf_i386_link_hash_entry *eh; struct elf_dyn_relocs **pp; struct elf_dyn_relocs *p; eh = (struct elf_i386_link_hash_entry *) h; for (pp = &eh->dyn_relocs; (p = *pp) != NULL; pp = &p->next) if (p->sec == sec) { /* Everything must go for SEC. */ *pp = p->next; break; } } r_type = ELF32_R_TYPE (rel->r_info); if (! elf_i386_tls_transition (info, abfd, sec, NULL, symtab_hdr, sym_hashes, &r_type, GOT_UNKNOWN, rel, relend, h, r_symndx)) return FALSE; switch (r_type) { case R_386_TLS_LDM: if (htab->tls_ldm_got.refcount > 0) htab->tls_ldm_got.refcount -= 1; break; case R_386_TLS_GD: case R_386_TLS_GOTDESC: case R_386_TLS_DESC_CALL: case R_386_TLS_IE_32: case R_386_TLS_IE: case R_386_TLS_GOTIE: case R_386_GOT32: if (h != NULL) { if (h->got.refcount > 0) h->got.refcount -= 1; if (h->type == STT_GNU_IFUNC) { if (h->plt.refcount > 0) h->plt.refcount -= 1; } } else if (local_got_refcounts != NULL) { if (local_got_refcounts[r_symndx] > 0) local_got_refcounts[r_symndx] -= 1; } break; case R_386_32: case R_386_PC32: if (info->shared && (h == NULL || h->type != STT_GNU_IFUNC)) break; /* Fall through */ case R_386_PLT32: if (h != NULL) { if (h->plt.refcount > 0) h->plt.refcount -= 1; } break; case R_386_GOTOFF: if (h != NULL && h->type == STT_GNU_IFUNC) { if (h->got.refcount > 0) h->got.refcount -= 1; if (h->plt.refcount > 0) h->plt.refcount -= 1; } break; default: break; } } 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_i386_adjust_dynamic_symbol (struct bfd_link_info *info, struct elf_link_hash_entry *h) { struct elf_i386_link_hash_table *htab; asection *s; /* STT_GNU_IFUNC symbol must go through PLT. */ if (h->type == STT_GNU_IFUNC) { if (h->plt.refcount <= 0) { h->plt.offset = (bfd_vma) -1; h->needs_plt = 0; } return TRUE; } /* If this is a function, put it in the procedure linkage table. We will fill in the contents of the procedure linkage table later, when we know the address of the .got section. */ if (h->type == STT_FUNC || h->needs_plt) { if (h->plt.refcount <= 0 || SYMBOL_CALLS_LOCAL (info, h) || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT && h->root.type == bfd_link_hash_undefweak)) { /* This case can occur if we saw a PLT32 reloc in an input file, but the symbol was never referred to by a dynamic object, or if all references were garbage collected. In such a case, we don't actually need to build a procedure linkage table, and we can just do a PC32 reloc instead. */ h->plt.offset = (bfd_vma) -1; h->needs_plt = 0; } return TRUE; } else /* It's possible that we incorrectly decided a .plt reloc was needed for an R_386_PC32 reloc to a non-function sym in check_relocs. We can't decide accurately between function and non-function syms in check-relocs; Objects loaded later in the link may change h->type. So fix it now. */ h->plt.offset = (bfd_vma) -1; /* 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 != NULL) { 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; if (ELIMINATE_COPY_RELOCS || info->nocopyreloc) h->non_got_ref = h->u.weakdef->non_got_ref; return TRUE; } /* This is a reference to a symbol defined by a dynamic object which is not a function. */ /* If we are creating a shared library, we must presume that the only references to the symbol are via the global offset table. For such cases we need not do anything here; the relocations will be handled correctly by relocate_section. */ if (info->shared) return TRUE; /* If there are no references to this symbol that do not use the GOT, we don't need to generate a copy reloc. */ if (!h->non_got_ref) return TRUE; /* If -z nocopyreloc was given, we won't generate them either. */ if (info->nocopyreloc) { h->non_got_ref = 0; return TRUE; } htab = elf_i386_hash_table (info); if (htab == NULL) return FALSE; /* If there aren't any dynamic relocs in read-only sections, then we can keep the dynamic relocs and avoid the copy reloc. This doesn't work on VxWorks, where we can not have dynamic relocations (other than copy and jump slot relocations) in an executable. */ if (ELIMINATE_COPY_RELOCS && !get_elf_i386_backend_data (info->output_bfd)->is_vxworks) { struct elf_i386_link_hash_entry * eh; struct elf_dyn_relocs *p; eh = (struct elf_i386_link_hash_entry *) h; for (p = eh->dyn_relocs; p != NULL; p = p->next) { s = p->sec->output_section; if (s != NULL && (s->flags & SEC_READONLY) != 0) break; } if (p == NULL) { h->non_got_ref = 0; return TRUE; } } if (h->size == 0) { (*_bfd_error_handler) (_("dynamic variable `%s' is zero size"), h->root.root.string); return TRUE; } /* We must allocate the symbol in our .dynbss section, which will become part of the .bss section of the executable. There will be an entry for this symbol in the .dynsym section. The dynamic object will contain position independent code, so all references from the dynamic object to this symbol will go through the global offset table. The dynamic linker will use the .dynsym entry to determine the address it must put in the global offset table, so both the dynamic object and the regular object will refer to the same memory location for the variable. */ /* We must generate a R_386_COPY reloc to tell the dynamic linker to copy the initial value out of the dynamic object and into the runtime process image. */ if ((h->root.u.def.section->flags & SEC_ALLOC) != 0) { htab->srelbss->size += sizeof (Elf32_External_Rel); h->needs_copy = 1; } s = htab->sdynbss; return _bfd_elf_adjust_dynamic_copy (h, s); } /* Allocate space in .plt, .got and associated reloc sections for dynamic relocs. */ static bfd_boolean elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) { struct bfd_link_info *info; struct elf_i386_link_hash_table *htab; struct elf_i386_link_hash_entry *eh; struct elf_dyn_relocs *p; unsigned plt_entry_size; if (h->root.type == bfd_link_hash_indirect) return TRUE; eh = (struct elf_i386_link_hash_entry *) h; info = (struct bfd_link_info *) inf; htab = elf_i386_hash_table (info); if (htab == NULL) return FALSE; plt_entry_size = GET_PLT_ENTRY_SIZE (info->output_bfd); /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it here if it is defined and referenced in a non-shared object. */ if (h->type == STT_GNU_IFUNC && h->def_regular) return _bfd_elf_allocate_ifunc_dyn_relocs (info, h, &eh->dyn_relocs, plt_entry_size, 4); else if (htab->elf.dynamic_sections_created && h->plt.refcount > 0) { /* Make sure this symbol is output as a dynamic symbol. Undefined weak syms won't yet be marked as dynamic. */ if (h->dynindx == -1 && !h->forced_local) { if (! bfd_elf_link_record_dynamic_symbol (info, h)) return FALSE; } if (info->shared || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h)) { asection *s = htab->elf.splt; /* If this is the first .plt entry, make room for the special first entry. */ if (s->size == 0) s->size += plt_entry_size; h->plt.offset = s->size; /* If this symbol is not defined in a regular file, and we are not generating a shared library, then set the symbol to this location in the .plt. This is required to make function pointers compare as equal between the normal executable and the shared library. */ if (! info->shared && !h->def_regular) { h->root.u.def.section = s; h->root.u.def.value = h->plt.offset; } /* Make room for this entry. */ s->size += plt_entry_size; /* We also need to make an entry in the .got.plt section, which will be placed in the .got section by the linker script. */ htab->elf.sgotplt->size += 4; /* We also need to make an entry in the .rel.plt section. */ htab->elf.srelplt->size += sizeof (Elf32_External_Rel); htab->elf.srelplt->reloc_count++; if (get_elf_i386_backend_data (info->output_bfd)->is_vxworks && !info->shared) { /* VxWorks has a second set of relocations for each PLT entry in executables. They go in a separate relocation section, which is processed by the kernel loader. */ /* There are two relocations for the initial PLT entry: an R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 4 and an R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 8. */ if (h->plt.offset == plt_entry_size) htab->srelplt2->size += (sizeof (Elf32_External_Rel) * 2); /* There are two extra relocations for each subsequent PLT entry: an R_386_32 relocation for the GOT entry, and an R_386_32 relocation for the PLT entry. */ htab->srelplt2->size += (sizeof (Elf32_External_Rel) * 2); } } else { h->plt.offset = (bfd_vma) -1; h->needs_plt = 0; } } else { h->plt.offset = (bfd_vma) -1; h->needs_plt = 0; } eh->tlsdesc_got = (bfd_vma) -1; /* If R_386_TLS_{IE_32,IE,GOTIE} symbol is now local to the binary, make it a R_386_TLS_LE_32 requiring no TLS entry. */ if (h->got.refcount > 0 && info->executable && h->dynindx == -1 && (elf_i386_hash_entry(h)->tls_type & GOT_TLS_IE)) h->got.offset = (bfd_vma) -1; else if (h->got.refcount > 0) { asection *s; bfd_boolean dyn; int tls_type = elf_i386_hash_entry(h)->tls_type; /* Make sure this symbol is output as a dynamic symbol. Undefined weak syms won't yet be marked as dynamic. */ if (h->dynindx == -1 && !h->forced_local) { if (! bfd_elf_link_record_dynamic_symbol (info, h)) return FALSE; } s = htab->elf.sgot; if (GOT_TLS_GDESC_P (tls_type)) { eh->tlsdesc_got = htab->elf.sgotplt->size - elf_i386_compute_jump_table_size (htab); htab->elf.sgotplt->size += 8; h->got.offset = (bfd_vma) -2; } if (! GOT_TLS_GDESC_P (tls_type) || GOT_TLS_GD_P (tls_type)) { h->got.offset = s->size; s->size += 4; /* R_386_TLS_GD needs 2 consecutive GOT slots. */ if (GOT_TLS_GD_P (tls_type) || tls_type == GOT_TLS_IE_BOTH) s->size += 4; } dyn = htab->elf.dynamic_sections_created; /* R_386_TLS_IE_32 needs one dynamic relocation, R_386_TLS_IE resp. R_386_TLS_GOTIE needs one dynamic relocation, (but if both R_386_TLS_IE_32 and R_386_TLS_IE is present, we need two), R_386_TLS_GD needs one if local symbol and two if global. */ if (tls_type == GOT_TLS_IE_BOTH) htab->elf.srelgot->size += 2 * sizeof (Elf32_External_Rel); else if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1) || (tls_type & GOT_TLS_IE)) htab->elf.srelgot->size += sizeof (Elf32_External_Rel); else if (GOT_TLS_GD_P (tls_type)) htab->elf.srelgot->size += 2 * sizeof (Elf32_External_Rel); else if (! GOT_TLS_GDESC_P (tls_type) && (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT || h->root.type != bfd_link_hash_undefweak) && (info->shared || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h))) htab->elf.srelgot->size += sizeof (Elf32_External_Rel); if (GOT_TLS_GDESC_P (tls_type)) htab->elf.srelplt->size += sizeof (Elf32_External_Rel); } else h->got.offset = (bfd_vma) -1; if (eh->dyn_relocs == NULL) return TRUE; /* In the shared -Bsymbolic case, discard space allocated for dynamic pc-relative relocs against symbols which turn out to be defined in regular objects. For the normal shared case, discard space for pc-relative relocs that have become local due to symbol visibility changes. */ if (info->shared) { /* The only reloc that uses pc_count is R_386_PC32, which will appear on a call or on something like ".long foo - .". We want calls to protected symbols to resolve directly to the function rather than going via the plt. If people want function pointer comparisons to work as expected then they should avoid writing assembly like ".long foo - .". */ if (SYMBOL_CALLS_LOCAL (info, h)) { struct elf_dyn_relocs **pp; for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) { p->count -= p->pc_count; p->pc_count = 0; if (p->count == 0) *pp = p->next; else pp = &p->next; } } if (get_elf_i386_backend_data (info->output_bfd)->is_vxworks) { struct elf_dyn_relocs **pp; for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) { if (strcmp (p->sec->output_section->name, ".tls_vars") == 0) *pp = p->next; else pp = &p->next; } } /* Also discard relocs on undefined weak syms with non-default visibility. */ if (eh->dyn_relocs != NULL && h->root.type == bfd_link_hash_undefweak) { if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT) eh->dyn_relocs = NULL; /* Make sure undefined weak symbols are output as a dynamic symbol in PIEs. */ else if (h->dynindx == -1 && !h->forced_local) { if (! bfd_elf_link_record_dynamic_symbol (info, h)) return FALSE; } } } else if (ELIMINATE_COPY_RELOCS) { /* For the non-shared case, discard space for relocs against symbols which turn out to need copy relocs or are not dynamic. */ if (!h->non_got_ref && ((h->def_dynamic && !h->def_regular) || (htab->elf.dynamic_sections_created && (h->root.type == bfd_link_hash_undefweak || h->root.type == bfd_link_hash_undefined)))) { /* Make sure this symbol is output as a dynamic symbol. Undefined weak syms won't yet be marked as dynamic. */ if (h->dynindx == -1 && !h->forced_local) { if (! bfd_elf_link_record_dynamic_symbol (info, h)) return FALSE; } /* If that succeeded, we know we'll be keeping all the relocs. */ if (h->dynindx != -1) goto keep; } eh->dyn_relocs = NULL; keep: ; } /* Finally, allocate space. */ for (p = eh->dyn_relocs; p != NULL; p = p->next) { asection *sreloc; sreloc = elf_section_data (p->sec)->sreloc; BFD_ASSERT (sreloc != NULL); sreloc->size += p->count * sizeof (Elf32_External_Rel); } return TRUE; } /* Allocate space in .plt, .got and associated reloc sections for local dynamic relocs. */ static bfd_boolean elf_i386_allocate_local_dynrelocs (void **slot, void *inf) { struct elf_link_hash_entry *h = (struct elf_link_hash_entry *) *slot; if (h->type != STT_GNU_IFUNC || !h->def_regular || !h->ref_regular || !h->forced_local || h->root.type != bfd_link_hash_defined) abort (); return elf_i386_allocate_dynrelocs (h, inf); } /* Find any dynamic relocs that apply to read-only sections. */ static bfd_boolean elf_i386_readonly_dynrelocs (struct elf_link_hash_entry *h, void *inf) { struct elf_i386_link_hash_entry *eh; struct elf_dyn_relocs *p; /* Skip local IFUNC symbols. */ if (h->forced_local && h->type == STT_GNU_IFUNC) return TRUE; eh = (struct elf_i386_link_hash_entry *) h; for (p = eh->dyn_relocs; p != NULL; p = p->next) { asection *s = p->sec->output_section; if (s != NULL && (s->flags & SEC_READONLY) != 0) { struct bfd_link_info *info = (struct bfd_link_info *) inf; info->flags |= DF_TEXTREL; if (info->warn_shared_textrel && info->shared) info->callbacks->einfo (_("%P: %B: warning: relocation against `%s' in readonly section `%A'.\n"), p->sec->owner, h->root.root.string, p->sec); /* Not an error, just cut short the traversal. */ return FALSE; } } return TRUE; } /* Set the sizes of the dynamic sections. */ static bfd_boolean elf_i386_size_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info) { struct elf_i386_link_hash_table *htab; bfd *dynobj; asection *s; bfd_boolean relocs; bfd *ibfd; htab = elf_i386_hash_table (info); if (htab == NULL) return FALSE; dynobj = htab->elf.dynobj; if (dynobj == NULL) abort (); if (htab->elf.dynamic_sections_created) { /* 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; } } /* Set up .got offsets for local syms, and space for local dynamic relocs. */ for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link_next) { bfd_signed_vma *local_got; bfd_signed_vma *end_local_got; char *local_tls_type; bfd_vma *local_tlsdesc_gotent; bfd_size_type locsymcount; Elf_Internal_Shdr *symtab_hdr; asection *srel; if (! is_i386_elf (ibfd)) continue; for (s = ibfd->sections; s != NULL; s = s->next) { struct elf_dyn_relocs *p; for (p = ((struct elf_dyn_relocs *) elf_section_data (s)->local_dynrel); p != NULL; p = p->next) { if (!bfd_is_abs_section (p->sec) && bfd_is_abs_section (p->sec->output_section)) { /* Input section has been discarded, either because it is a copy of a linkonce section or due to linker script /DISCARD/, so we'll be discarding the relocs too. */ } else if (get_elf_i386_backend_data (output_bfd)->is_vxworks && strcmp (p->sec->output_section->name, ".tls_vars") == 0) { /* Relocations in vxworks .tls_vars sections are handled specially by the loader. */ } else if (p->count != 0) { srel = elf_section_data (p->sec)->sreloc; srel->size += p->count * sizeof (Elf32_External_Rel); if ((p->sec->output_section->flags & SEC_READONLY) != 0 && (info->flags & DF_TEXTREL) == 0) { info->flags |= DF_TEXTREL; if (info->warn_shared_textrel && info->shared) info->callbacks->einfo (_("%P: %B: warning: relocation in readonly section `%A'.\n"), p->sec->owner, p->sec); } } } } local_got = elf_local_got_refcounts (ibfd); if (!local_got) continue; symtab_hdr = &elf_symtab_hdr (ibfd); locsymcount = symtab_hdr->sh_info; end_local_got = local_got + locsymcount; local_tls_type = elf_i386_local_got_tls_type (ibfd); local_tlsdesc_gotent = elf_i386_local_tlsdesc_gotent (ibfd); s = htab->elf.sgot; srel = htab->elf.srelgot; for (; local_got < end_local_got; ++local_got, ++local_tls_type, ++local_tlsdesc_gotent) { *local_tlsdesc_gotent = (bfd_vma) -1; if (*local_got > 0) { if (GOT_TLS_GDESC_P (*local_tls_type)) { *local_tlsdesc_gotent = htab->elf.sgotplt->size - elf_i386_compute_jump_table_size (htab); htab->elf.sgotplt->size += 8; *local_got = (bfd_vma) -2; } if (! GOT_TLS_GDESC_P (*local_tls_type) || GOT_TLS_GD_P (*local_tls_type)) { *local_got = s->size; s->size += 4; if (GOT_TLS_GD_P (*local_tls_type) || *local_tls_type == GOT_TLS_IE_BOTH) s->size += 4; } if (info->shared || GOT_TLS_GD_ANY_P (*local_tls_type) || (*local_tls_type & GOT_TLS_IE)) { if (*local_tls_type == GOT_TLS_IE_BOTH) srel->size += 2 * sizeof (Elf32_External_Rel); else if (GOT_TLS_GD_P (*local_tls_type) || ! GOT_TLS_GDESC_P (*local_tls_type)) srel->size += sizeof (Elf32_External_Rel); if (GOT_TLS_GDESC_P (*local_tls_type)) htab->elf.srelplt->size += sizeof (Elf32_External_Rel); } } else *local_got = (bfd_vma) -1; } } if (htab->tls_ldm_got.refcount > 0) { /* Allocate 2 got entries and 1 dynamic reloc for R_386_TLS_LDM relocs. */ htab->tls_ldm_got.offset = htab->elf.sgot->size; htab->elf.sgot->size += 8; htab->elf.srelgot->size += sizeof (Elf32_External_Rel); } else htab->tls_ldm_got.offset = -1; /* Allocate global sym .plt and .got entries, and space for global sym dynamic relocs. */ elf_link_hash_traverse (&htab->elf, elf_i386_allocate_dynrelocs, info); /* Allocate .plt and .got entries, and space for local symbols. */ htab_traverse (htab->loc_hash_table, elf_i386_allocate_local_dynrelocs, info); /* For every jump slot reserved in the sgotplt, reloc_count is incremented. However, when we reserve space for TLS descriptors, it's not incremented, so in order to compute the space reserved for them, it suffices to multiply the reloc count by the jump slot size. PR ld/13302: We start next_irelative_index at the end of .rela.plt so that R_386_IRELATIVE entries come last. */ if (htab->elf.srelplt) { htab->next_tls_desc_index = htab->elf.srelplt->reloc_count; htab->sgotplt_jump_table_size = htab->next_tls_desc_index * 4; htab->next_irelative_index = htab->elf.srelplt->reloc_count - 1; } else if (htab->elf.irelplt) htab->next_irelative_index = htab->elf.irelplt->reloc_count - 1; if (htab->elf.sgotplt) { struct elf_link_hash_entry *got; got = elf_link_hash_lookup (elf_hash_table (info), "_GLOBAL_OFFSET_TABLE_", FALSE, FALSE, FALSE); /* Don't allocate .got.plt section if there are no GOT nor PLT entries and there is no refeence to _GLOBAL_OFFSET_TABLE_. */ if ((got == NULL || !got->ref_regular_nonweak) && (htab->elf.sgotplt->size == get_elf_backend_data (output_bfd)->got_header_size) && (htab->elf.splt == NULL || htab->elf.splt->size == 0) && (htab->elf.sgot == NULL || htab->elf.sgot->size == 0) && (htab->elf.iplt == NULL || htab->elf.iplt->size == 0) && (htab->elf.igotplt == NULL || htab->elf.igotplt->size == 0)) htab->elf.sgotplt->size = 0; } /* We now have determined the sizes of the various dynamic sections. Allocate memory for them. */ relocs = FALSE; for (s = dynobj->sections; s != NULL; s = s->next) { bfd_boolean strip_section = TRUE; if ((s->flags & SEC_LINKER_CREATED) == 0) continue; if (s == htab->elf.splt || s == htab->elf.sgot || s == htab->elf.sgotplt || s == htab->elf.iplt || s == htab->elf.igotplt || s == htab->sdynbss) { /* Strip this section if we don't need it; see the comment below. */ /* We'd like to strip these sections if they aren't needed, but if we've exported dynamic symbols from them we must leave them. It's too late to tell BFD to get rid of the symbols. */ if (htab->elf.hplt != NULL) strip_section = FALSE; } else if (CONST_STRNEQ (bfd_get_section_name (dynobj, s), ".rel")) { if (s->size != 0 && s != htab->elf.srelplt && s != htab->srelplt2) relocs = 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 { /* 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. This is mostly to handle .rel.bss and .rel.plt. We must create both sections in create_dynamic_sections, because they must be created before the linker maps input sections to output sections. The linker does that before adjust_dynamic_symbol is called, and it is that function which decides whether anything needs to go into these sections. */ if (strip_section) s->flags |= SEC_EXCLUDE; continue; } if ((s->flags & SEC_HAS_CONTENTS) == 0) continue; /* Allocate memory for the section contents. We use bfd_zalloc here in case unused entries are not reclaimed before the section's contents are written out. This should not happen, but this way if it does, we get a R_386_NONE reloc instead of garbage. */ s->contents = (unsigned char *) bfd_zalloc (dynobj, s->size); if (s->contents == NULL) return FALSE; } if (htab->plt_eh_frame != NULL && htab->elf.splt != NULL && htab->elf.splt->size != 0 && (htab->elf.splt->flags & SEC_EXCLUDE) == 0) bfd_put_32 (dynobj, htab->elf.splt->size, htab->plt_eh_frame->contents + PLT_FDE_LEN_OFFSET); if (htab->elf.dynamic_sections_created) { /* Add some entries to the .dynamic section. We fill in the values later, in elf_i386_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 (htab->elf.splt->size != 0) { if (!add_dynamic_entry (DT_PLTGOT, 0) || !add_dynamic_entry (DT_PLTRELSZ, 0) || !add_dynamic_entry (DT_PLTREL, DT_REL) || !add_dynamic_entry (DT_JMPREL, 0)) return FALSE; } if (relocs) { if (!add_dynamic_entry (DT_REL, 0) || !add_dynamic_entry (DT_RELSZ, 0) || !add_dynamic_entry (DT_RELENT, sizeof (Elf32_External_Rel))) return FALSE; /* If any dynamic relocs apply to a read-only section, then we need a DT_TEXTREL entry. */ if ((info->flags & DF_TEXTREL) == 0) elf_link_hash_traverse (&htab->elf, elf_i386_readonly_dynrelocs, info); if ((info->flags & DF_TEXTREL) != 0) { if (!add_dynamic_entry (DT_TEXTREL, 0)) return FALSE; } } if (get_elf_i386_backend_data (output_bfd)->is_vxworks && !elf_vxworks_add_dynamic_entries (output_bfd, info)) return FALSE; } #undef add_dynamic_entry return TRUE; } static bfd_boolean elf_i386_always_size_sections (bfd *output_bfd, struct bfd_link_info *info) { asection *tls_sec = elf_hash_table (info)->tls_sec; if (tls_sec) { struct elf_link_hash_entry *tlsbase; tlsbase = elf_link_hash_lookup (elf_hash_table (info), "_TLS_MODULE_BASE_", FALSE, FALSE, FALSE); if (tlsbase && tlsbase->type == STT_TLS) { struct elf_i386_link_hash_table *htab; struct bfd_link_hash_entry *bh = NULL; const struct elf_backend_data *bed = get_elf_backend_data (output_bfd); htab = elf_i386_hash_table (info); if (htab == NULL) return FALSE; 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; htab->tls_module_base = bh; tlsbase = (struct elf_link_hash_entry *)bh; tlsbase->def_regular = 1; tlsbase->other = STV_HIDDEN; (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE); } } return TRUE; } /* Set the correct type for an x86 ELF section. We do this by the section name, which is a hack, but ought to work. */ static bfd_boolean elf_i386_fake_sections (bfd *abfd ATTRIBUTE_UNUSED, Elf_Internal_Shdr *hdr, asection *sec) { const char *name; name = bfd_get_section_name (abfd, sec); /* This is an ugly, but unfortunately necessary hack that is needed when producing EFI binaries on x86. It tells elf.c:elf_fake_sections() not to consider ".reloc" as a section containing ELF relocation info. We need this hack in order to be able to generate ELF binaries that can be translated into EFI applications (which are essentially COFF objects). Those files contain a COFF ".reloc" section inside an ELFNN object, which would normally cause BFD to segfault because it would attempt to interpret this section as containing relocation entries for section "oc". With this hack enabled, ".reloc" will be treated as a normal data section, which will avoid the segfault. However, you won't be able to create an ELFNN binary with a section named "oc" that needs relocations, but that's the kind of ugly side-effects you get when detecting section types based on their names... In practice, this limitation is unlikely to bite. */ if (strcmp (name, ".reloc") == 0) hdr->sh_type = SHT_PROGBITS; return TRUE; } /* _TLS_MODULE_BASE_ needs to be treated especially when linking executables. Rather than setting it to the beginning of the TLS section, we have to set it to the end. This function may be called multiple times, it is idempotent. */ static void elf_i386_set_tls_module_base (struct bfd_link_info *info) { struct elf_i386_link_hash_table *htab; struct bfd_link_hash_entry *base; if (!info->executable) return; htab = elf_i386_hash_table (info); if (htab == NULL) return; base = htab->tls_module_base; if (base == NULL) return; base->u.def.value = htab->elf.tls_size; } /* 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 elf_i386_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 elf_i386_tpoff (struct bfd_link_info *info, bfd_vma address) { struct elf_link_hash_table *htab = elf_hash_table (info); const struct elf_backend_data *bed = get_elf_backend_data (info->output_bfd); bfd_vma static_tls_size; /* If tls_sec is NULL, we should have signalled an error already. */ if (htab->tls_sec == NULL) return 0; /* Consider special static TLS alignment requirements. */ static_tls_size = BFD_ALIGN (htab->tls_size, bed->static_tls_alignment); return static_tls_size + htab->tls_sec->vma - address; } /* Relocate an i386 ELF section. */ static bfd_boolean elf_i386_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_i386_link_hash_table *htab; Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes; bfd_vma *local_got_offsets; bfd_vma *local_tlsdesc_gotents; Elf_Internal_Rela *rel; Elf_Internal_Rela *relend; bfd_boolean is_vxworks_tls; unsigned plt_entry_size; BFD_ASSERT (is_i386_elf (input_bfd)); htab = elf_i386_hash_table (info); if (htab == NULL) return FALSE; symtab_hdr = &elf_symtab_hdr (input_bfd); sym_hashes = elf_sym_hashes (input_bfd); local_got_offsets = elf_local_got_offsets (input_bfd); local_tlsdesc_gotents = elf_i386_local_tlsdesc_gotent (input_bfd); /* We have to handle relocations in vxworks .tls_vars sections specially, because the dynamic loader is 'weird'. */ is_vxworks_tls = (get_elf_i386_backend_data (output_bfd)->is_vxworks && info->shared && !strcmp (input_section->output_section->name, ".tls_vars")); elf_i386_set_tls_module_base (info); plt_entry_size = GET_PLT_ENTRY_SIZE (output_bfd); rel = relocs; relend = relocs + input_section->reloc_count; for (; rel < relend; rel++) { unsigned int r_type; reloc_howto_type *howto; unsigned long r_symndx; struct elf_link_hash_entry *h; Elf_Internal_Sym *sym; asection *sec; bfd_vma off, offplt; bfd_vma relocation; bfd_boolean unresolved_reloc; bfd_reloc_status_type r; unsigned int indx; int tls_type; r_type = ELF32_R_TYPE (rel->r_info); if (r_type == R_386_GNU_VTINHERIT || r_type == R_386_GNU_VTENTRY) continue; if ((indx = r_type) >= R_386_standard && ((indx = r_type - R_386_ext_offset) - R_386_standard >= R_386_ext - R_386_standard) && ((indx = r_type - R_386_tls_offset) - R_386_ext >= R_386_irelative - R_386_ext)) { (*_bfd_error_handler) (_("%B: unrecognized relocation (0x%x) in section `%A'"), input_bfd, input_section, r_type); bfd_set_error (bfd_error_bad_value); return FALSE; } howto = elf_howto_table + indx; r_symndx = ELF32_R_SYM (rel->r_info); h = NULL; sym = NULL; sec = NULL; unresolved_reloc = FALSE; if (r_symndx < symtab_hdr->sh_info) { sym = local_syms + r_symndx; sec = local_sections[r_symndx]; relocation = (sec->output_section->vma + sec->output_offset + sym->st_value); if (ELF_ST_TYPE (sym->st_info) == STT_SECTION && ((sec->flags & SEC_MERGE) != 0 || (info->relocatable && sec->output_offset != 0))) { bfd_vma addend; bfd_byte *where = contents + rel->r_offset; switch (howto->size) { case 0: addend = bfd_get_8 (input_bfd, where); if (howto->pc_relative) { addend = (addend ^ 0x80) - 0x80; addend += 1; } break; case 1: addend = bfd_get_16 (input_bfd, where); if (howto->pc_relative) { addend = (addend ^ 0x8000) - 0x8000; addend += 2; } break; case 2: addend = bfd_get_32 (input_bfd, where); if (howto->pc_relative) { addend = (addend ^ 0x80000000) - 0x80000000; addend += 4; } break; default: abort (); } if (info->relocatable) addend += sec->output_offset; else { asection *msec = sec; addend = _bfd_elf_rel_local_sym (output_bfd, sym, &msec, addend); addend -= relocation; addend += msec->output_section->vma + msec->output_offset; } switch (howto->size) { case 0: /* FIXME: overflow checks. */ if (howto->pc_relative) addend -= 1; bfd_put_8 (input_bfd, addend, where); break; case 1: if (howto->pc_relative) addend -= 2; bfd_put_16 (input_bfd, addend, where); break; case 2: if (howto->pc_relative) addend -= 4; bfd_put_32 (input_bfd, addend, where); break; } } else if (!info->relocatable && ELF32_ST_TYPE (sym->st_info) == STT_GNU_IFUNC) { /* Relocate against local STT_GNU_IFUNC symbol. */ h = elf_i386_get_local_sym_hash (htab, input_bfd, rel, FALSE); if (h == NULL) abort (); /* Set STT_GNU_IFUNC symbol value. */ h->root.u.def.value = sym->st_value; h->root.u.def.section = sec; } } else { bfd_boolean warned ATTRIBUTE_UNUSED; RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel, r_symndx, symtab_hdr, sym_hashes, h, sec, relocation, unresolved_reloc, warned); } if (sec != NULL && elf_discarded_section (sec)) RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section, rel, relend, howto, contents); if (info->relocatable) continue; /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it here if it is defined in a non-shared object. */ if (h != NULL && h->type == STT_GNU_IFUNC && h->def_regular) { asection *plt, *gotplt, *base_got; bfd_vma plt_index; const char *name; if ((input_section->flags & SEC_ALLOC) == 0 || h->plt.offset == (bfd_vma) -1) abort (); /* STT_GNU_IFUNC symbol must go through PLT. */ if (htab->elf.splt != NULL) { plt = htab->elf.splt; gotplt = htab->elf.sgotplt; } else { plt = htab->elf.iplt; gotplt = htab->elf.igotplt; } relocation = (plt->output_section->vma + plt->output_offset + h->plt.offset); switch (r_type) { default: if (h->root.root.string) name = h->root.root.string; else name = bfd_elf_sym_name (input_bfd, symtab_hdr, sym, NULL); (*_bfd_error_handler) (_("%B: relocation %s against STT_GNU_IFUNC " "symbol `%s' isn't handled by %s"), input_bfd, elf_howto_table[r_type].name, name, __FUNCTION__); bfd_set_error (bfd_error_bad_value); return FALSE; case R_386_32: /* Generate dynamic relcoation only when there is a non-GOT reference in a shared object. */ if (info->shared && h->non_got_ref) { Elf_Internal_Rela outrel; bfd_byte *loc; asection *sreloc; bfd_vma offset; bfd_boolean relocate; /* Need a dynamic relocation to get the real function adddress. */ offset = _bfd_elf_section_offset (output_bfd, info, input_section, rel->r_offset); if (offset == (bfd_vma) -1 || offset == (bfd_vma) -2) abort (); outrel.r_offset = (input_section->output_section->vma + input_section->output_offset + offset); if (h->dynindx == -1 || h->forced_local || info->executable) { /* This symbol is resolved locally. */ outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE); relocate = TRUE; } else { outrel.r_info = ELF32_R_INFO (h->dynindx, r_type); relocate = FALSE; } sreloc = htab->elf.irelifunc; loc = sreloc->contents; loc += (sreloc->reloc_count++ * sizeof (Elf32_External_Rel)); bfd_elf32_swap_reloc_out (output_bfd, &outrel, loc); /* If this reloc is against an external symbol, we do not want to fiddle with the addend. Otherwise, we need to include the symbol value so that it becomes an addend for the dynamic reloc. For an internal symbol, we have updated addend. */ if (! relocate) continue; } /* FALLTHROUGH */ case R_386_PC32: case R_386_PLT32: goto do_relocation; case R_386_GOT32: base_got = htab->elf.sgot; off = h->got.offset; if (base_got == NULL) abort (); if (off == (bfd_vma) -1) { /* We can't use h->got.offset here to save state, or even just remember the offset, as finish_dynamic_symbol would use that as offset into .got. */ if (htab->elf.splt != NULL) { plt_index = h->plt.offset / plt_entry_size - 1; off = (plt_index + 3) * 4; base_got = htab->elf.sgotplt; } else { plt_index = h->plt.offset / plt_entry_size; off = plt_index * 4; base_got = htab->elf.igotplt; } if (h->dynindx == -1 || h->forced_local || info->symbolic) { /* This references the local defitionion. We must initialize this entry in the global offset table. Since the offset must always be a multiple of 8, we use the least significant bit to record whether we have initialized it already. When doing a dynamic link, we create a .rela.got relocation entry to initialize the value. This is done in the finish_dynamic_symbol routine. */ if ((off & 1) != 0) off &= ~1; else { bfd_put_32 (output_bfd, relocation, base_got->contents + off); h->got.offset |= 1; } } relocation = off; /* Adjust for static executables. */ if (htab->elf.splt == NULL) relocation += gotplt->output_offset; } else { relocation = (base_got->output_section->vma + base_got->output_offset + off - gotplt->output_section->vma - gotplt->output_offset); /* Adjust for static executables. */ if (htab->elf.splt == NULL) relocation += gotplt->output_offset; } goto do_relocation; case R_386_GOTOFF: relocation -= (gotplt->output_section->vma + gotplt->output_offset); goto do_relocation; } } switch (r_type) { case R_386_GOT32: /* Relocation is to the entry for this symbol in the global offset table. */ if (htab->elf.sgot == NULL) abort (); if (h != NULL) { bfd_boolean dyn; off = h->got.offset; dyn = htab->elf.dynamic_sections_created; if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h) || (info->shared && SYMBOL_REFERENCES_LOCAL (info, h)) || (ELF_ST_VISIBILITY (h->other) && h->root.type == bfd_link_hash_undefweak)) { /* This is actually a static link, or it is a -Bsymbolic link and the symbol is defined locally, or the symbol was forced to be local because of a version file. We must initialize this entry in the global offset table. Since the offset must always be a multiple of 4, we use the least significant bit to record whether we have initialized it already. When doing a dynamic link, we create a .rel.got relocation entry to initialize the value. This is done in the finish_dynamic_symbol routine. */ if ((off & 1) != 0) off &= ~1; else { bfd_put_32 (output_bfd, relocation, htab->elf.sgot->contents + off); h->got.offset |= 1; } } else unresolved_reloc = FALSE; } else { if (local_got_offsets == NULL) abort (); off = local_got_offsets[r_symndx]; /* The offset must always be a multiple of 4. We use the least significant bit to record whether we have already generated the necessary reloc. */ if ((off & 1) != 0) off &= ~1; else { bfd_put_32 (output_bfd, relocation, htab->elf.sgot->contents + off); if (info->shared) { asection *s; Elf_Internal_Rela outrel; bfd_byte *loc; s = htab->elf.srelgot; if (s == NULL) abort (); outrel.r_offset = (htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off); outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE); loc = s->contents; loc += s->reloc_count++ * sizeof (Elf32_External_Rel); bfd_elf32_swap_reloc_out (output_bfd, &outrel, loc); } local_got_offsets[r_symndx] |= 1; } } if (off >= (bfd_vma) -2) abort (); relocation = htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off - htab->elf.sgotplt->output_section->vma - htab->elf.sgotplt->output_offset; break; case R_386_GOTOFF: /* Relocation is relative to the start of the global offset table. */ /* Check to make sure it isn't a protected function symbol for shared library since it may not be local when used as function address. We also need to make sure that a symbol is defined locally. */ if (info->shared && h) { if (!h->def_regular) { const char *v; switch (ELF_ST_VISIBILITY (h->other)) { case STV_HIDDEN: v = _("hidden symbol"); break; case STV_INTERNAL: v = _("internal symbol"); break; case STV_PROTECTED: v = _("protected symbol"); break; default: v = _("symbol"); break; } (*_bfd_error_handler) (_("%B: relocation R_386_GOTOFF against undefined %s `%s' can not be used when making a shared object"), input_bfd, v, h->root.root.string); bfd_set_error (bfd_error_bad_value); return FALSE; } else if (!info->executable && h->type == STT_FUNC && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED) { (*_bfd_error_handler) (_("%B: relocation R_386_GOTOFF against protected function `%s' can not be used when making a shared object"), input_bfd, h->root.root.string); bfd_set_error (bfd_error_bad_value); return FALSE; } } /* Note that sgot is not involved in this calculation. We always want the start of .got.plt. If we defined _GLOBAL_OFFSET_TABLE_ in a different way, as is permitted by the ABI, we might have to change this calculation. */ relocation -= htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset; break; case R_386_GOTPC: /* Use global offset table as symbol value. */ relocation = htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset; unresolved_reloc = FALSE; break; case R_386_PLT32: /* Relocation is to the entry for this symbol in the procedure linkage table. */ /* Resolve a PLT32 reloc against a local symbol directly, without using the procedure linkage table. */ if (h == NULL) break; if (h->plt.offset == (bfd_vma) -1 || htab->elf.splt == NULL) { /* We didn't make a PLT entry for this symbol. This happens when statically linking PIC code, or when using -Bsymbolic. */ break; } relocation = (htab->elf.splt->output_section->vma + htab->elf.splt->output_offset + h->plt.offset); unresolved_reloc = FALSE; break; case R_386_32: case R_386_PC32: if ((input_section->flags & SEC_ALLOC) == 0 || is_vxworks_tls) break; if ((info->shared && (h == NULL || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT || h->root.type != bfd_link_hash_undefweak) && (r_type != R_386_PC32 || !SYMBOL_CALLS_LOCAL (info, h))) || (ELIMINATE_COPY_RELOCS && !info->shared && h != NULL && h->dynindx != -1 && !h->non_got_ref && ((h->def_dynamic && !h->def_regular) || h->root.type == bfd_link_hash_undefweak || h->root.type == bfd_link_hash_undefined))) { Elf_Internal_Rela outrel; bfd_byte *loc; bfd_boolean skip, relocate; asection *sreloc; /* When generating a shared object, these relocations are copied into the output file to be resolved at run time. */ skip = FALSE; relocate = FALSE; outrel.r_offset = _bfd_elf_section_offset (output_bfd, info, input_section, rel->r_offset); if (outrel.r_offset == (bfd_vma) -1) skip = TRUE; else if (outrel.r_offset == (bfd_vma) -2) skip = TRUE, relocate = TRUE; outrel.r_offset += (input_section->output_section->vma + input_section->output_offset); if (skip) memset (&outrel, 0, sizeof outrel); else if (h != NULL && h->dynindx != -1 && (r_type == R_386_PC32 || !info->shared || !SYMBOLIC_BIND (info, h) || !h->def_regular)) outrel.r_info = ELF32_R_INFO (h->dynindx, r_type); else { /* This symbol is local, or marked to become local. */ relocate = TRUE; outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE); } sreloc = elf_section_data (input_section)->sreloc; if (sreloc == NULL || sreloc->contents == NULL) { r = bfd_reloc_notsupported; goto check_relocation_error; } loc = sreloc->contents; loc += sreloc->reloc_count++ * sizeof (Elf32_External_Rel); bfd_elf32_swap_reloc_out (output_bfd, &outrel, loc); /* If this reloc is against an external symbol, we do not want to fiddle with the addend. Otherwise, we need to include the symbol value so that it becomes an addend for the dynamic reloc. */ if (! relocate) continue; } break; case R_386_TLS_IE: if (!info->executable) { Elf_Internal_Rela outrel; bfd_byte *loc; asection *sreloc; outrel.r_offset = rel->r_offset + input_section->output_section->vma + input_section->output_offset; outrel.r_info = ELF32_R_INFO (0, R_386_RELATIVE); sreloc = elf_section_data (input_section)->sreloc; if (sreloc == NULL) abort (); loc = sreloc->contents; loc += sreloc->reloc_count++ * sizeof (Elf32_External_Rel); bfd_elf32_swap_reloc_out (output_bfd, &outrel, loc); } /* Fall through */ case R_386_TLS_GD: case R_386_TLS_GOTDESC: case R_386_TLS_DESC_CALL: case R_386_TLS_IE_32: case R_386_TLS_GOTIE: tls_type = GOT_UNKNOWN; if (h == NULL && local_got_offsets) tls_type = elf_i386_local_got_tls_type (input_bfd) [r_symndx]; else if (h != NULL) tls_type = elf_i386_hash_entry(h)->tls_type; if (tls_type == GOT_TLS_IE) tls_type = GOT_TLS_IE_NEG; if (! elf_i386_tls_transition (info, input_bfd, input_section, contents, symtab_hdr, sym_hashes, &r_type, tls_type, rel, relend, h, r_symndx)) return FALSE; if (r_type == R_386_TLS_LE_32) { BFD_ASSERT (! unresolved_reloc); if (ELF32_R_TYPE (rel->r_info) == R_386_TLS_GD) { unsigned int type; bfd_vma roff; /* GD->LE transition. */ type = bfd_get_8 (input_bfd, contents + rel->r_offset - 2); if (type == 0x04) { /* leal foo(,%reg,1), %eax; call ___tls_get_addr Change it into: movl %gs:0, %eax; subl $foo@tpoff, %eax (6 byte form of subl). */ memcpy (contents + rel->r_offset - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); roff = rel->r_offset + 5; } else { /* leal foo(%reg), %eax; call ___tls_get_addr; nop Change it into: movl %gs:0, %eax; subl $foo@tpoff, %eax (6 byte form of subl). */ memcpy (contents + rel->r_offset - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); roff = rel->r_offset + 6; } bfd_put_32 (output_bfd, elf_i386_tpoff (info, relocation), contents + roff); /* Skip R_386_PC32/R_386_PLT32. */ rel++; continue; } else if (ELF32_R_TYPE (rel->r_info) == R_386_TLS_GOTDESC) { /* GDesc -> LE transition. It's originally something like: leal x@tlsdesc(%ebx), %eax leal x@ntpoff, %eax Registers other than %eax may be set up here. */ unsigned int val; bfd_vma roff; roff = rel->r_offset; val = bfd_get_8 (input_bfd, contents + roff - 1); /* Now modify the instruction as appropriate. */ /* aoliva FIXME: remove the above and xor the byte below with 0x86. */ bfd_put_8 (output_bfd, val ^ 0x86, contents + roff - 1); bfd_put_32 (output_bfd, -elf_i386_tpoff (info, relocation), contents + roff); continue; } else if (ELF32_R_TYPE (rel->r_info) == R_386_TLS_DESC_CALL) { /* GDesc -> LE transition. It's originally: call *(%eax) Turn it into: xchg %ax,%ax */ bfd_vma roff; roff = rel->r_offset; bfd_put_8 (output_bfd, 0x66, contents + roff); bfd_put_8 (output_bfd, 0x90, contents + roff + 1); continue; } else if (ELF32_R_TYPE (rel->r_info) == R_386_TLS_IE) { unsigned int val; /* IE->LE transition: Originally it can be one of: movl foo, %eax movl foo, %reg addl foo, %reg We change it into: movl $foo, %eax movl $foo, %reg addl $foo, %reg. */ val = bfd_get_8 (input_bfd, contents + rel->r_offset - 1); if (val == 0xa1) { /* movl foo, %eax. */ bfd_put_8 (output_bfd, 0xb8, contents + rel->r_offset - 1); } else { unsigned int type; type = bfd_get_8 (input_bfd, contents + rel->r_offset - 2); switch (type) { case 0x8b: /* movl */ bfd_put_8 (output_bfd, 0xc7, contents + rel->r_offset - 2); bfd_put_8 (output_bfd, 0xc0 | ((val >> 3) & 7), contents + rel->r_offset - 1); break; case 0x03: /* addl */ bfd_put_8 (output_bfd, 0x81, contents + rel->r_offset - 2); bfd_put_8 (output_bfd, 0xc0 | ((val >> 3) & 7), contents + rel->r_offset - 1); break; default: BFD_FAIL (); break; } } bfd_put_32 (output_bfd, -elf_i386_tpoff (info, relocation), contents + rel->r_offset); continue; } else { unsigned int val, type; /* {IE_32,GOTIE}->LE transition: Originally it can be one of: subl foo(%reg1), %reg2 movl foo(%reg1), %reg2 addl foo(%reg1), %reg2 We change it into: subl $foo, %reg2 movl $foo, %reg2 (6 byte form) addl $foo, %reg2. */ type = bfd_get_8 (input_bfd, contents + rel->r_offset - 2); val = bfd_get_8 (input_bfd, contents + rel->r_offset - 1); if (type == 0x8b) { /* movl */ bfd_put_8 (output_bfd, 0xc7, contents + rel->r_offset - 2); bfd_put_8 (output_bfd, 0xc0 | ((val >> 3) & 7), contents + rel->r_offset - 1); } else if (type == 0x2b) { /* subl */ bfd_put_8 (output_bfd, 0x81, contents + rel->r_offset - 2); bfd_put_8 (output_bfd, 0xe8 | ((val >> 3) & 7), contents + rel->r_offset - 1); } else if (type == 0x03) { /* addl */ bfd_put_8 (output_bfd, 0x81, contents + rel->r_offset - 2); bfd_put_8 (output_bfd, 0xc0 | ((val >> 3) & 7), contents + rel->r_offset - 1); } else BFD_FAIL (); if (ELF32_R_TYPE (rel->r_info) == R_386_TLS_GOTIE) bfd_put_32 (output_bfd, -elf_i386_tpoff (info, relocation), contents + rel->r_offset); else bfd_put_32 (output_bfd, elf_i386_tpoff (info, relocation), contents + rel->r_offset); continue; } } if (htab->elf.sgot == NULL) abort (); if (h != NULL) { off = h->got.offset; offplt = elf_i386_hash_entry (h)->tlsdesc_got; } else { if (local_got_offsets == NULL) abort (); off = local_got_offsets[r_symndx]; offplt = local_tlsdesc_gotents[r_symndx]; } if ((off & 1) != 0) off &= ~1; else { Elf_Internal_Rela outrel; bfd_byte *loc; int dr_type; asection *sreloc; if (htab->elf.srelgot == NULL) abort (); indx = h && h->dynindx != -1 ? h->dynindx : 0; if (GOT_TLS_GDESC_P (tls_type)) { outrel.r_info = ELF32_R_INFO (indx, R_386_TLS_DESC); BFD_ASSERT (htab->sgotplt_jump_table_size + offplt + 8 <= htab->elf.sgotplt->size); outrel.r_offset = (htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset + offplt + htab->sgotplt_jump_table_size); sreloc = htab->elf.srelplt; loc = sreloc->contents; loc += (htab->next_tls_desc_index++ * sizeof (Elf32_External_Rel)); BFD_ASSERT (loc + sizeof (Elf32_External_Rel) <= sreloc->contents + sreloc->size); bfd_elf32_swap_reloc_out (output_bfd, &outrel, loc); if (indx == 0) { BFD_ASSERT (! unresolved_reloc); bfd_put_32 (output_bfd, relocation - elf_i386_dtpoff_base (info), htab->elf.sgotplt->contents + offplt + htab->sgotplt_jump_table_size + 4); } else { bfd_put_32 (output_bfd, 0, htab->elf.sgotplt->contents + offplt + htab->sgotplt_jump_table_size + 4); } } sreloc = htab->elf.srelgot; outrel.r_offset = (htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off); if (GOT_TLS_GD_P (tls_type)) dr_type = R_386_TLS_DTPMOD32; else if (GOT_TLS_GDESC_P (tls_type)) goto dr_done; else if (tls_type == GOT_TLS_IE_POS) dr_type = R_386_TLS_TPOFF; else dr_type = R_386_TLS_TPOFF32; if (dr_type == R_386_TLS_TPOFF && indx == 0) bfd_put_32 (output_bfd, relocation - elf_i386_dtpoff_base (info), htab->elf.sgot->contents + off); else if (dr_type == R_386_TLS_TPOFF32 && indx == 0) bfd_put_32 (output_bfd, elf_i386_dtpoff_base (info) - relocation, htab->elf.sgot->contents + off); else if (dr_type != R_386_TLS_DESC) bfd_put_32 (output_bfd, 0, htab->elf.sgot->contents + off); outrel.r_info = ELF32_R_INFO (indx, dr_type); loc = sreloc->contents; loc += sreloc->reloc_count++ * sizeof (Elf32_External_Rel); BFD_ASSERT (loc + sizeof (Elf32_External_Rel) <= sreloc->contents + sreloc->size); bfd_elf32_swap_reloc_out (output_bfd, &outrel, loc); if (GOT_TLS_GD_P (tls_type)) { if (indx == 0) { BFD_ASSERT (! unresolved_reloc); bfd_put_32 (output_bfd, relocation - elf_i386_dtpoff_base (info), htab->elf.sgot->contents + off + 4); } else { bfd_put_32 (output_bfd, 0, htab->elf.sgot->contents + off + 4); outrel.r_info = ELF32_R_INFO (indx, R_386_TLS_DTPOFF32); outrel.r_offset += 4; sreloc->reloc_count++; loc += sizeof (Elf32_External_Rel); BFD_ASSERT (loc + sizeof (Elf32_External_Rel) <= sreloc->contents + sreloc->size); bfd_elf32_swap_reloc_out (output_bfd, &outrel, loc); } } else if (tls_type == GOT_TLS_IE_BOTH) { bfd_put_32 (output_bfd, (indx == 0 ? relocation - elf_i386_dtpoff_base (info) : 0), htab->elf.sgot->contents + off + 4); outrel.r_info = ELF32_R_INFO (indx, R_386_TLS_TPOFF); outrel.r_offset += 4; sreloc->reloc_count++; loc += sizeof (Elf32_External_Rel); bfd_elf32_swap_reloc_out (output_bfd, &outrel, loc); } dr_done: if (h != NULL) h->got.offset |= 1; else local_got_offsets[r_symndx] |= 1; } if (off >= (bfd_vma) -2 && ! GOT_TLS_GDESC_P (tls_type)) abort (); if (r_type == R_386_TLS_GOTDESC || r_type == R_386_TLS_DESC_CALL) { relocation = htab->sgotplt_jump_table_size + offplt; unresolved_reloc = FALSE; } else if (r_type == ELF32_R_TYPE (rel->r_info)) { bfd_vma g_o_t = htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset; relocation = htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off - g_o_t; if ((r_type == R_386_TLS_IE || r_type == R_386_TLS_GOTIE) && tls_type == GOT_TLS_IE_BOTH) relocation += 4; if (r_type == R_386_TLS_IE) relocation += g_o_t; unresolved_reloc = FALSE; } else if (ELF32_R_TYPE (rel->r_info) == R_386_TLS_GD) { unsigned int val, type; bfd_vma roff; /* GD->IE transition. */ type = bfd_get_8 (input_bfd, contents + rel->r_offset - 2); val = bfd_get_8 (input_bfd, contents + rel->r_offset - 1); if (type == 0x04) { /* leal foo(,%reg,1), %eax; call ___tls_get_addr Change it into: movl %gs:0, %eax; subl $foo@gottpoff(%reg), %eax. */ val >>= 3; roff = rel->r_offset - 3; } else { /* leal foo(%reg), %eax; call ___tls_get_addr; nop Change it into: movl %gs:0, %eax; subl $foo@gottpoff(%reg), %eax. */ roff = rel->r_offset - 2; } memcpy (contents + roff, "\x65\xa1\0\0\0\0\x2b\x80\0\0\0", 12); contents[roff + 7] = 0x80 | (val & 7); /* If foo is used only with foo@gotntpoff(%reg) and foo@indntpoff, but not with foo@gottpoff(%reg), change subl $foo@gottpoff(%reg), %eax into: addl $foo@gotntpoff(%reg), %eax. */ if (tls_type == GOT_TLS_IE_POS) contents[roff + 6] = 0x03; bfd_put_32 (output_bfd, htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off - htab->elf.sgotplt->output_section->vma - htab->elf.sgotplt->output_offset, contents + roff + 8); /* Skip R_386_PLT32. */ rel++; continue; } else if (ELF32_R_TYPE (rel->r_info) == R_386_TLS_GOTDESC) { /* GDesc -> IE transition. It's originally something like: leal x@tlsdesc(%ebx), %eax Change it to: movl x@gotntpoff(%ebx), %eax # before xchg %ax,%ax or: movl x@gottpoff(%ebx), %eax # before negl %eax Registers other than %eax may be set up here. */ bfd_vma roff; /* First, make sure it's a leal adding ebx to a 32-bit offset into any register, although it's probably almost always going to be eax. */ roff = rel->r_offset; /* Now modify the instruction as appropriate. */ /* To turn a leal into a movl in the form we use it, it suffices to change the first byte from 0x8d to 0x8b. aoliva FIXME: should we decide to keep the leal, all we have to do is remove the statement below, and adjust the relaxation of R_386_TLS_DESC_CALL. */ bfd_put_8 (output_bfd, 0x8b, contents + roff - 2); if (tls_type == GOT_TLS_IE_BOTH) off += 4; bfd_put_32 (output_bfd, htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off - htab->elf.sgotplt->output_section->vma - htab->elf.sgotplt->output_offset, contents + roff); continue; } else if (ELF32_R_TYPE (rel->r_info) == R_386_TLS_DESC_CALL) { /* GDesc -> IE transition. It's originally: call *(%eax) Change it to: xchg %ax,%ax or negl %eax depending on how we transformed the TLS_GOTDESC above. */ bfd_vma roff; roff = rel->r_offset; /* Now modify the instruction as appropriate. */ if (tls_type != GOT_TLS_IE_NEG) { /* xchg %ax,%ax */ bfd_put_8 (output_bfd, 0x66, contents + roff); bfd_put_8 (output_bfd, 0x90, contents + roff + 1); } else { /* negl %eax */ bfd_put_8 (output_bfd, 0xf7, contents + roff); bfd_put_8 (output_bfd, 0xd8, contents + roff + 1); } continue; } else BFD_ASSERT (FALSE); break; case R_386_TLS_LDM: if (! elf_i386_tls_transition (info, input_bfd, input_section, contents, symtab_hdr, sym_hashes, &r_type, GOT_UNKNOWN, rel, relend, h, r_symndx)) return FALSE; if (r_type != R_386_TLS_LDM) { /* LD->LE transition: leal foo(%reg), %eax; call ___tls_get_addr. We change it into: movl %gs:0, %eax; nop; leal 0(%esi,1), %esi. */ BFD_ASSERT (r_type == R_386_TLS_LE_32); memcpy (contents + rel->r_offset - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26", 11); /* Skip R_386_PC32/R_386_PLT32. */ rel++; continue; } if (htab->elf.sgot == NULL) abort (); off = htab->tls_ldm_got.offset; if (off & 1) off &= ~1; else { Elf_Internal_Rela outrel; bfd_byte *loc; if (htab->elf.srelgot == NULL) abort (); outrel.r_offset = (htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off); bfd_put_32 (output_bfd, 0, htab->elf.sgot->contents + off); bfd_put_32 (output_bfd, 0, htab->elf.sgot->contents + off + 4); outrel.r_info = ELF32_R_INFO (0, R_386_TLS_DTPMOD32); loc = htab->elf.srelgot->contents; loc += htab->elf.srelgot->reloc_count++ * sizeof (Elf32_External_Rel); bfd_elf32_swap_reloc_out (output_bfd, &outrel, loc); htab->tls_ldm_got.offset |= 1; } relocation = htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off - htab->elf.sgotplt->output_section->vma - htab->elf.sgotplt->output_offset; unresolved_reloc = FALSE; break; case R_386_TLS_LDO_32: if (!info->executable || (input_section->flags & SEC_CODE) == 0) relocation -= elf_i386_dtpoff_base (info); else /* When converting LDO to LE, we must negate. */ relocation = -elf_i386_tpoff (info, relocation); break; case R_386_TLS_LE_32: case R_386_TLS_LE: if (!info->executable) { Elf_Internal_Rela outrel; asection *sreloc; bfd_byte *loc; outrel.r_offset = rel->r_offset + input_section->output_section->vma + input_section->output_offset; if (h != NULL && h->dynindx != -1) indx = h->dynindx; else indx = 0; if (r_type == R_386_TLS_LE_32) outrel.r_info = ELF32_R_INFO (indx, R_386_TLS_TPOFF32); else outrel.r_info = ELF32_R_INFO (indx, R_386_TLS_TPOFF); sreloc = elf_section_data (input_section)->sreloc; if (sreloc == NULL) abort (); loc = sreloc->contents; loc += sreloc->reloc_count++ * sizeof (Elf32_External_Rel); bfd_elf32_swap_reloc_out (output_bfd, &outrel, loc); if (indx) continue; else if (r_type == R_386_TLS_LE_32) relocation = elf_i386_dtpoff_base (info) - relocation; else relocation -= elf_i386_dtpoff_base (info); } else if (r_type == R_386_TLS_LE_32) relocation = elf_i386_tpoff (info, relocation); else relocation = -elf_i386_tpoff (info, relocation); break; default: 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_elf_section_offset (output_bfd, info, input_section, rel->r_offset) != (bfd_vma) -1) { (*_bfd_error_handler) (_("%B(%A+0x%lx): unresolvable %s relocation against symbol `%s'"), input_bfd, input_section, (long) rel->r_offset, howto->name, h->root.root.string); return FALSE; } do_relocation: r = _bfd_final_link_relocate (howto, input_bfd, input_section, contents, rel->r_offset, relocation, 0); check_relocation_error: if (r != bfd_reloc_ok) { const char *name; 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) return FALSE; if (*name == '\0') name = bfd_section_name (input_bfd, sec); } if (r == bfd_reloc_overflow) { if (! ((*info->callbacks->reloc_overflow) (info, (h ? &h->root : NULL), name, howto->name, (bfd_vma) 0, input_bfd, input_section, rel->r_offset))) return FALSE; } else { (*_bfd_error_handler) (_("%B(%A+0x%lx): reloc against `%s': error %d"), input_bfd, input_section, (long) rel->r_offset, name, (int) r); return FALSE; } } } return TRUE; } /* Finish up dynamic symbol handling. We set the contents of various dynamic sections here. */ static bfd_boolean elf_i386_finish_dynamic_symbol (bfd *output_bfd, struct bfd_link_info *info, struct elf_link_hash_entry *h, Elf_Internal_Sym *sym) { struct elf_i386_link_hash_table *htab; unsigned plt_entry_size; const struct elf_i386_backend_data *abed; htab = elf_i386_hash_table (info); if (htab == NULL) return FALSE; abed = get_elf_i386_backend_data (output_bfd); plt_entry_size = GET_PLT_ENTRY_SIZE (output_bfd); if (h->plt.offset != (bfd_vma) -1) { bfd_vma plt_index; bfd_vma got_offset; Elf_Internal_Rela rel; bfd_byte *loc; asection *plt, *gotplt, *relplt; /* When building a static executable, use .iplt, .igot.plt and .rel.iplt sections for STT_GNU_IFUNC symbols. */ if (htab->elf.splt != NULL) { plt = htab->elf.splt; gotplt = htab->elf.sgotplt; relplt = htab->elf.srelplt; } else { plt = htab->elf.iplt; gotplt = htab->elf.igotplt; relplt = htab->elf.irelplt; } /* This symbol has an entry in the procedure linkage table. Set it up. */ if ((h->dynindx == -1 && !((h->forced_local || info->executable) && h->def_regular && h->type == STT_GNU_IFUNC)) || plt == NULL || gotplt == NULL || relplt == NULL) return FALSE; /* Get the index in the procedure linkage table which corresponds to this symbol. This is the index of this symbol in all the symbols for which we are making plt entries. The first entry in the procedure linkage table is reserved. Get the offset into the .got table of the entry that corresponds to this function. Each .got entry is 4 bytes. The first three are reserved. For static executables, we don't reserve anything. */ if (plt == htab->elf.splt) { got_offset = h->plt.offset / plt_entry_size - 1; got_offset = (got_offset + 3) * 4; } else { got_offset = h->plt.offset / plt_entry_size; got_offset = got_offset * 4; } /* Fill in the entry in the procedure linkage table. */ if (! info->shared) { memcpy (plt->contents + h->plt.offset, abed->plt->plt_entry, abed->plt->plt_entry_size); bfd_put_32 (output_bfd, (gotplt->output_section->vma + gotplt->output_offset + got_offset), plt->contents + h->plt.offset + abed->plt->plt_got_offset); if (abed->is_vxworks) { int s, k, reloc_index; /* Create the R_386_32 relocation referencing the GOT for this PLT entry. */ /* S: Current slot number (zero-based). */ s = ((h->plt.offset - abed->plt->plt_entry_size) / abed->plt->plt_entry_size); /* K: Number of relocations for PLTResolve. */ if (info->shared) k = PLTRESOLVE_RELOCS_SHLIB; else k = PLTRESOLVE_RELOCS; /* Skip the PLTresolve relocations, and the relocations for the other PLT slots. */ reloc_index = k + s * PLT_NON_JUMP_SLOT_RELOCS; loc = (htab->srelplt2->contents + reloc_index * sizeof (Elf32_External_Rel)); rel.r_offset = (htab->elf.splt->output_section->vma + htab->elf.splt->output_offset + h->plt.offset + 2), rel.r_info = ELF32_R_INFO (htab->elf.hgot->indx, R_386_32); bfd_elf32_swap_reloc_out (output_bfd, &rel, loc); /* Create the R_386_32 relocation referencing the beginning of the PLT for this GOT entry. */ rel.r_offset = (htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset + got_offset); rel.r_info = ELF32_R_INFO (htab->elf.hplt->indx, R_386_32); bfd_elf32_swap_reloc_out (output_bfd, &rel, loc + sizeof (Elf32_External_Rel)); } } else { memcpy (plt->contents + h->plt.offset, abed->plt->pic_plt_entry, abed->plt->plt_entry_size); bfd_put_32 (output_bfd, got_offset, plt->contents + h->plt.offset + abed->plt->plt_got_offset); } /* Fill in the entry in the global offset table. */ bfd_put_32 (output_bfd, (plt->output_section->vma + plt->output_offset + h->plt.offset + abed->plt->plt_lazy_offset), gotplt->contents + got_offset); /* Fill in the entry in the .rel.plt section. */ rel.r_offset = (gotplt->output_section->vma + gotplt->output_offset + got_offset); if (h->dynindx == -1 || ((info->executable || ELF_ST_VISIBILITY (h->other) != STV_DEFAULT) && h->def_regular && h->type == STT_GNU_IFUNC)) { /* If an STT_GNU_IFUNC symbol is locally defined, generate R_386_IRELATIVE instead of R_386_JUMP_SLOT. Store addend in the .got.plt section. */ bfd_put_32 (output_bfd, (h->root.u.def.value + h->root.u.def.section->output_section->vma + h->root.u.def.section->output_offset), gotplt->contents + got_offset); rel.r_info = ELF32_R_INFO (0, R_386_IRELATIVE); /* R_386_IRELATIVE comes last. */ plt_index = htab->next_irelative_index--; } else { rel.r_info = ELF32_R_INFO (h->dynindx, R_386_JUMP_SLOT); plt_index = htab->next_jump_slot_index++; } loc = relplt->contents + plt_index * sizeof (Elf32_External_Rel); bfd_elf32_swap_reloc_out (output_bfd, &rel, loc); /* Don't fill PLT entry for static executables. */ if (plt == htab->elf.splt) { bfd_put_32 (output_bfd, plt_index * sizeof (Elf32_External_Rel), plt->contents + h->plt.offset + abed->plt->plt_reloc_offset); bfd_put_32 (output_bfd, - (h->plt.offset + abed->plt->plt_plt_offset + 4), plt->contents + h->plt.offset + abed->plt->plt_plt_offset); } if (!h->def_regular) { /* Mark the symbol as undefined, rather than as defined in the .plt section. Leave the value if there were any relocations where pointer equality matters (this is a clue for the dynamic linker, to make function pointer comparisons work between an application and shared library), otherwise set it to zero. If a function is only called from a binary, there is no need to slow down shared libraries because of that. */ sym->st_shndx = SHN_UNDEF; if (!h->pointer_equality_needed) sym->st_value = 0; } } if (h->got.offset != (bfd_vma) -1 && ! GOT_TLS_GD_ANY_P (elf_i386_hash_entry(h)->tls_type) && (elf_i386_hash_entry(h)->tls_type & GOT_TLS_IE) == 0) { Elf_Internal_Rela rel; bfd_byte *loc; /* This symbol has an entry in the global offset table. Set it up. */ if (htab->elf.sgot == NULL || htab->elf.srelgot == NULL) abort (); rel.r_offset = (htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + (h->got.offset & ~(bfd_vma) 1)); /* If this is a static link, or it is a -Bsymbolic link and the symbol is defined locally or was forced to be local because of a version file, we just want to emit a RELATIVE reloc. The entry in the global offset table will already have been initialized in the relocate_section function. */ if (h->def_regular && h->type == STT_GNU_IFUNC) { if (info->shared) { /* Generate R_386_GLOB_DAT. */ goto do_glob_dat; } else { asection *plt; if (!h->pointer_equality_needed) abort (); /* For non-shared object, we can't use .got.plt, which contains the real function addres if we need pointer equality. We load the GOT entry with the PLT entry. */ plt = htab->elf.splt ? htab->elf.splt : htab->elf.iplt; bfd_put_32 (output_bfd, (plt->output_section->vma + plt->output_offset + h->plt.offset), htab->elf.sgot->contents + h->got.offset); return TRUE; } } else if (info->shared && SYMBOL_REFERENCES_LOCAL (info, h)) { BFD_ASSERT((h->got.offset & 1) != 0); rel.r_info = ELF32_R_INFO (0, R_386_RELATIVE); } else { BFD_ASSERT((h->got.offset & 1) == 0); do_glob_dat: bfd_put_32 (output_bfd, (bfd_vma) 0, htab->elf.sgot->contents + h->got.offset); rel.r_info = ELF32_R_INFO (h->dynindx, R_386_GLOB_DAT); } loc = htab->elf.srelgot->contents; loc += htab->elf.srelgot->reloc_count++ * sizeof (Elf32_External_Rel); bfd_elf32_swap_reloc_out (output_bfd, &rel, loc); } if (h->needs_copy) { Elf_Internal_Rela rel; bfd_byte *loc; /* This symbol needs a copy reloc. Set it up. */ if (h->dynindx == -1 || (h->root.type != bfd_link_hash_defined && h->root.type != bfd_link_hash_defweak) || htab->srelbss == NULL) abort (); rel.r_offset = (h->root.u.def.value + h->root.u.def.section->output_section->vma + h->root.u.def.section->output_offset); rel.r_info = ELF32_R_INFO (h->dynindx, R_386_COPY); loc = htab->srelbss->contents; loc += htab->srelbss->reloc_count++ * sizeof (Elf32_External_Rel); bfd_elf32_swap_reloc_out (output_bfd, &rel, loc); } /* Mark _DYNAMIC and _GLOBAL_OFFSET_TABLE_ as absolute. SYM may be NULL for local symbols. On VxWorks, the _GLOBAL_OFFSET_TABLE_ symbol is not absolute: it is relative to the ".got" section. */ if (sym != NULL && (strcmp (h->root.root.string, "_DYNAMIC") == 0 || (!abed->is_vxworks && h == htab->elf.hgot))) sym->st_shndx = SHN_ABS; return TRUE; } /* Finish up local dynamic symbol handling. We set the contents of various dynamic sections here. */ static bfd_boolean elf_i386_finish_local_dynamic_symbol (void **slot, void *inf) { struct elf_link_hash_entry *h = (struct elf_link_hash_entry *) *slot; struct bfd_link_info *info = (struct bfd_link_info *) inf; return elf_i386_finish_dynamic_symbol (info->output_bfd, info, h, NULL); } /* Used to decide how to sort relocs in an optimal manner for the dynamic linker, before writing them out. */ static enum elf_reloc_type_class elf_i386_reloc_type_class (const Elf_Internal_Rela *rela) { switch (ELF32_R_TYPE (rela->r_info)) { case R_386_RELATIVE: return reloc_class_relative; case R_386_JUMP_SLOT: return reloc_class_plt; case R_386_COPY: return reloc_class_copy; default: return reloc_class_normal; } } /* Finish up the dynamic sections. */ static bfd_boolean elf_i386_finish_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info) { struct elf_i386_link_hash_table *htab; bfd *dynobj; asection *sdyn; const struct elf_i386_backend_data *abed; htab = elf_i386_hash_table (info); if (htab == NULL) return FALSE; dynobj = htab->elf.dynobj; sdyn = bfd_get_section_by_name (dynobj, ".dynamic"); abed = get_elf_i386_backend_data (output_bfd); if (htab->elf.dynamic_sections_created) { Elf32_External_Dyn *dyncon, *dynconend; if (sdyn == NULL || htab->elf.sgot == NULL) abort (); dyncon = (Elf32_External_Dyn *) sdyn->contents; dynconend = (Elf32_External_Dyn *) (sdyn->contents + sdyn->size); for (; dyncon < dynconend; dyncon++) { Elf_Internal_Dyn dyn; asection *s; bfd_elf32_swap_dyn_in (dynobj, dyncon, &dyn); switch (dyn.d_tag) { default: if (abed->is_vxworks && elf_vxworks_finish_dynamic_entry (output_bfd, &dyn)) break; continue; case DT_PLTGOT: s = htab->elf.sgotplt; dyn.d_un.d_ptr = s->output_section->vma + s->output_offset; break; case DT_JMPREL: s = htab->elf.srelplt; dyn.d_un.d_ptr = s->output_section->vma + s->output_offset; break; case DT_PLTRELSZ: s = htab->elf.srelplt; dyn.d_un.d_val = s->size; break; case DT_RELSZ: /* My reading of the SVR4 ABI indicates that the procedure linkage table relocs (DT_JMPREL) should be included in the overall relocs (DT_REL). This is what Solaris does. However, UnixWare can not handle that case. Therefore, we override the DT_RELSZ entry here to make it not include the JMPREL relocs. */ s = htab->elf.srelplt; if (s == NULL) continue; dyn.d_un.d_val -= s->size; break; case DT_REL: /* We may not be using the standard ELF linker script. If .rel.plt is the first .rel section, we adjust DT_REL to not include it. */ s = htab->elf.srelplt; if (s == NULL) continue; if (dyn.d_un.d_ptr != s->output_section->vma + s->output_offset) continue; dyn.d_un.d_ptr += s->size; break; } bfd_elf32_swap_dyn_out (output_bfd, &dyn, dyncon); } /* Fill in the first entry in the procedure linkage table. */ if (htab->elf.splt && htab->elf.splt->size > 0) { if (info->shared) { memcpy (htab->elf.splt->contents, abed->plt->pic_plt0_entry, abed->plt->plt0_entry_size); memset (htab->elf.splt->contents + abed->plt->plt0_entry_size, abed->plt0_pad_byte, abed->plt->plt_entry_size - abed->plt->plt0_entry_size); } else { memcpy (htab->elf.splt->contents, abed->plt->plt0_entry, abed->plt->plt0_entry_size); memset (htab->elf.splt->contents + abed->plt->plt0_entry_size, abed->plt0_pad_byte, abed->plt->plt_entry_size - abed->plt->plt0_entry_size); bfd_put_32 (output_bfd, (htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset + 4), htab->elf.splt->contents + abed->plt->plt0_got1_offset); bfd_put_32 (output_bfd, (htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset + 8), htab->elf.splt->contents + abed->plt->plt0_got2_offset); if (abed->is_vxworks) { Elf_Internal_Rela rel; /* Generate a relocation for _GLOBAL_OFFSET_TABLE_ + 4. On IA32 we use REL relocations so the addend goes in the PLT directly. */ rel.r_offset = (htab->elf.splt->output_section->vma + htab->elf.splt->output_offset + abed->plt->plt0_got1_offset); rel.r_info = ELF32_R_INFO (htab->elf.hgot->indx, R_386_32); bfd_elf32_swap_reloc_out (output_bfd, &rel, htab->srelplt2->contents); /* Generate a relocation for _GLOBAL_OFFSET_TABLE_ + 8. */ rel.r_offset = (htab->elf.splt->output_section->vma + htab->elf.splt->output_offset + abed->plt->plt0_got2_offset); rel.r_info = ELF32_R_INFO (htab->elf.hgot->indx, R_386_32); bfd_elf32_swap_reloc_out (output_bfd, &rel, htab->srelplt2->contents + sizeof (Elf32_External_Rel)); } } /* UnixWare sets the entsize of .plt to 4, although that doesn't really seem like the right value. */ elf_section_data (htab->elf.splt->output_section) ->this_hdr.sh_entsize = 4; /* Correct the .rel.plt.unloaded relocations. */ if (abed->is_vxworks && !info->shared) { int num_plts = (htab->elf.splt->size / abed->plt->plt_entry_size) - 1; unsigned char *p; p = htab->srelplt2->contents; if (info->shared) p += PLTRESOLVE_RELOCS_SHLIB * sizeof (Elf32_External_Rel); else p += PLTRESOLVE_RELOCS * sizeof (Elf32_External_Rel); for (; num_plts; num_plts--) { Elf_Internal_Rela rel; bfd_elf32_swap_reloc_in (output_bfd, p, &rel); rel.r_info = ELF32_R_INFO (htab->elf.hgot->indx, R_386_32); bfd_elf32_swap_reloc_out (output_bfd, &rel, p); p += sizeof (Elf32_External_Rel); bfd_elf32_swap_reloc_in (output_bfd, p, &rel); rel.r_info = ELF32_R_INFO (htab->elf.hplt->indx, R_386_32); bfd_elf32_swap_reloc_out (output_bfd, &rel, p); p += sizeof (Elf32_External_Rel); } } } } if (htab->elf.sgotplt) { if (bfd_is_abs_section (htab->elf.sgotplt->output_section)) { (*_bfd_error_handler) (_("discarded output section: `%A'"), htab->elf.sgotplt); return FALSE; } /* Fill in the first three entries in the global offset table. */ if (htab->elf.sgotplt->size > 0) { bfd_put_32 (output_bfd, (sdyn == NULL ? 0 : sdyn->output_section->vma + sdyn->output_offset), htab->elf.sgotplt->contents); bfd_put_32 (output_bfd, 0, htab->elf.sgotplt->contents + 4); bfd_put_32 (output_bfd, 0, htab->elf.sgotplt->contents + 8); } elf_section_data (htab->elf.sgotplt->output_section)->this_hdr.sh_entsize = 4; } /* Adjust .eh_frame for .plt section. */ if (htab->plt_eh_frame != NULL) { if (htab->elf.splt != NULL && htab->elf.splt->size != 0 && (htab->elf.splt->flags & SEC_EXCLUDE) == 0 && htab->elf.splt->output_section != NULL && htab->plt_eh_frame->output_section != NULL) { bfd_vma plt_start = htab->elf.splt->output_section->vma; bfd_vma eh_frame_start = htab->plt_eh_frame->output_section->vma + htab->plt_eh_frame->output_offset + PLT_FDE_START_OFFSET; bfd_put_signed_32 (dynobj, plt_start - eh_frame_start, htab->plt_eh_frame->contents + PLT_FDE_START_OFFSET); } if (htab->plt_eh_frame->sec_info_type == ELF_INFO_TYPE_EH_FRAME) { if (! _bfd_elf_write_section_eh_frame (output_bfd, info, htab->plt_eh_frame, htab->plt_eh_frame->contents)) return FALSE; } } if (htab->elf.sgot && htab->elf.sgot->size > 0) elf_section_data (htab->elf.sgot->output_section)->this_hdr.sh_entsize = 4; /* Fill PLT and GOT entries for local STT_GNU_IFUNC symbols. */ htab_traverse (htab->loc_hash_table, elf_i386_finish_local_dynamic_symbol, info); return TRUE; } /* Return address for Ith PLT stub in section PLT, for relocation REL or (bfd_vma) -1 if it should not be included. */ static bfd_vma elf_i386_plt_sym_val (bfd_vma i, const asection *plt, const arelent *rel ATTRIBUTE_UNUSED) { return plt->vma + (i + 1) * GET_PLT_ENTRY_SIZE (plt->owner); } /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */ static bfd_boolean elf_i386_hash_symbol (struct elf_link_hash_entry *h) { if (h->plt.offset != (bfd_vma) -1 && !h->def_regular && !h->pointer_equality_needed) return FALSE; return _bfd_elf_hash_symbol (h); } /* Hook called by the linker routine which adds symbols from an object file. */ static bfd_boolean elf_i386_add_symbol_hook (bfd * abfd, struct bfd_link_info * info ATTRIBUTE_UNUSED, Elf_Internal_Sym * sym, const char ** namep ATTRIBUTE_UNUSED, flagword * flagsp ATTRIBUTE_UNUSED, asection ** secp ATTRIBUTE_UNUSED, bfd_vma * valp ATTRIBUTE_UNUSED) { if ((abfd->flags & DYNAMIC) == 0 && (ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC || ELF_ST_BIND (sym->st_info) == STB_GNU_UNIQUE)) elf_tdata (info->output_bfd)->has_gnu_symbols = TRUE; return TRUE; } #define TARGET_LITTLE_SYM bfd_elf32_i386_vec #define TARGET_LITTLE_NAME "elf32-i386" #define ELF_ARCH bfd_arch_i386 #define ELF_TARGET_ID I386_ELF_DATA #define ELF_MACHINE_CODE EM_386 #define ELF_MAXPAGESIZE 0x1000 #define elf_backend_can_gc_sections 1 #define elf_backend_can_refcount 1 #define elf_backend_want_got_plt 1 #define elf_backend_plt_readonly 1 #define elf_backend_want_plt_sym 0 #define elf_backend_got_header_size 12 #define elf_backend_plt_alignment 4 /* Support RELA for objdump of prelink objects. */ #define elf_info_to_howto elf_i386_info_to_howto_rel #define elf_info_to_howto_rel elf_i386_info_to_howto_rel #define bfd_elf32_mkobject elf_i386_mkobject #define bfd_elf32_bfd_is_local_label_name elf_i386_is_local_label_name #define bfd_elf32_bfd_link_hash_table_create elf_i386_link_hash_table_create #define bfd_elf32_bfd_link_hash_table_free elf_i386_link_hash_table_free #define bfd_elf32_bfd_reloc_type_lookup elf_i386_reloc_type_lookup #define bfd_elf32_bfd_reloc_name_lookup elf_i386_reloc_name_lookup #define elf_backend_adjust_dynamic_symbol elf_i386_adjust_dynamic_symbol #define elf_backend_relocs_compatible _bfd_elf_relocs_compatible #define elf_backend_check_relocs elf_i386_check_relocs #define elf_backend_copy_indirect_symbol elf_i386_copy_indirect_symbol #define elf_backend_create_dynamic_sections elf_i386_create_dynamic_sections #define elf_backend_fake_sections elf_i386_fake_sections #define elf_backend_finish_dynamic_sections elf_i386_finish_dynamic_sections #define elf_backend_finish_dynamic_symbol elf_i386_finish_dynamic_symbol #define elf_backend_gc_mark_hook elf_i386_gc_mark_hook #define elf_backend_gc_sweep_hook elf_i386_gc_sweep_hook #define elf_backend_grok_prstatus elf_i386_grok_prstatus #define elf_backend_grok_psinfo elf_i386_grok_psinfo #define elf_backend_reloc_type_class elf_i386_reloc_type_class #define elf_backend_relocate_section elf_i386_relocate_section #define elf_backend_size_dynamic_sections elf_i386_size_dynamic_sections #define elf_backend_always_size_sections elf_i386_always_size_sections #define elf_backend_omit_section_dynsym \ ((bfd_boolean (*) (bfd *, struct bfd_link_info *, asection *)) bfd_true) #define elf_backend_plt_sym_val elf_i386_plt_sym_val #define elf_backend_hash_symbol elf_i386_hash_symbol #define elf_backend_add_symbol_hook elf_i386_add_symbol_hook #undef elf_backend_post_process_headers #define elf_backend_post_process_headers _bfd_elf_set_osabi #include "elf32-target.h" /* FreeBSD support. */ #undef TARGET_LITTLE_SYM #define TARGET_LITTLE_SYM bfd_elf32_i386_freebsd_vec #undef TARGET_LITTLE_NAME #define TARGET_LITTLE_NAME "elf32-i386-freebsd" #undef ELF_OSABI #define ELF_OSABI ELFOSABI_FREEBSD /* The kernel recognizes executables as valid only if they carry a "FreeBSD" label in the ELF header. So we put this label on all executables and (for simplicity) also all other object files. */ static void elf_i386_fbsd_post_process_headers (bfd *abfd, struct bfd_link_info *info) { _bfd_elf_set_osabi (abfd, info); #ifdef OLD_FREEBSD_ABI_LABEL /* The ABI label supported by FreeBSD <= 4.0 is quite nonstandard. */ memcpy (&i_ehdrp->e_ident[EI_ABIVERSION], "FreeBSD", 8); #endif } #undef elf_backend_post_process_headers #define elf_backend_post_process_headers elf_i386_fbsd_post_process_headers #undef elf32_bed #define elf32_bed elf32_i386_fbsd_bed #undef elf_backend_add_symbol_hook #include "elf32-target.h" /* Solaris 2. */ #undef TARGET_LITTLE_SYM #define TARGET_LITTLE_SYM bfd_elf32_i386_sol2_vec #undef TARGET_LITTLE_NAME #define TARGET_LITTLE_NAME "elf32-i386-sol2" /* Restore default: we cannot use ELFOSABI_SOLARIS, otherwise ELFOSABI_NONE objects won't be recognized. */ #undef ELF_OSABI #undef elf32_bed #define elf32_bed elf32_i386_sol2_bed /* The 32-bit static TLS arena size is rounded to the nearest 8-byte boundary. */ #undef elf_backend_static_tls_alignment #define elf_backend_static_tls_alignment 8 /* The Solaris 2 ABI requires a plt symbol on all platforms. Cf. Linker and Libraries Guide, Ch. 2, Link-Editor, Generating the Output File, p.63. */ #undef elf_backend_want_plt_sym #define elf_backend_want_plt_sym 1 #include "elf32-target.h" /* Native Client support. */ #undef TARGET_LITTLE_SYM #define TARGET_LITTLE_SYM bfd_elf32_i386_nacl_vec #undef TARGET_LITTLE_NAME #define TARGET_LITTLE_NAME "elf32-i386-nacl" #undef elf32_bed #define elf32_bed elf32_i386_nacl_bed #undef ELF_MAXPAGESIZE #define ELF_MAXPAGESIZE 0x10000 /* Restore defaults. */ #undef ELF_OSABI #undef elf_backend_want_plt_sym #define elf_backend_want_plt_sym 0 #undef elf_backend_post_process_headers #define elf_backend_post_process_headers _bfd_elf_set_osabi #undef elf_backend_static_tls_alignment /* NaCl uses substantially different PLT entries for the same effects. */ #undef elf_backend_plt_alignment #define elf_backend_plt_alignment 5 #define NACL_PLT_ENTRY_SIZE 64 #define NACLMASK 0xe0 /* 32-byte alignment mask. */ static const bfd_byte elf_i386_nacl_plt0_entry[] = { 0xff, 0x35, /* pushl contents of address */ 0, 0, 0, 0, /* replaced with address of .got + 4. */ 0x8b, 0x0d, /* movl contents of address, %ecx */ 0, 0, 0, 0, /* replaced with address of .got + 8. */ 0x83, 0xe1, NACLMASK, /* andl $NACLMASK, %ecx */ 0xff, 0xe1 /* jmp *%ecx */ }; static const bfd_byte elf_i386_nacl_plt_entry[NACL_PLT_ENTRY_SIZE] = { 0x8b, 0x0d, /* movl contents of address, %ecx */ 0, 0, 0, 0, /* replaced with GOT slot address. */ 0x83, 0xe1, NACLMASK, /* andl $NACLMASK, %ecx */ 0xff, 0xe1, /* jmp *%ecx */ /* Pad to the next 32-byte boundary with nop instructions. */ 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, /* Lazy GOT entries point here (32-byte aligned). */ 0x68, /* pushl immediate */ 0, 0, 0, 0, /* replaced with reloc offset. */ 0xe9, /* jmp relative */ 0, 0, 0, 0, /* replaced with offset to .plt. */ /* Pad to the next 32-byte boundary with nop instructions. */ 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90 }; static const bfd_byte elf_i386_nacl_pic_plt0_entry[sizeof (elf_i386_nacl_plt0_entry)] = { 0xff, 0x73, 0x04, /* pushl 4(%ebx) */ 0x8b, 0x4b, 0x08, /* mov 0x8(%ebx), %ecx */ 0x83, 0xe1, 0xe0, /* and $NACLMASK, %ecx */ 0xff, 0xe1, /* jmp *%ecx */ 0x90 /* nop */ }; static const bfd_byte elf_i386_nacl_pic_plt_entry[NACL_PLT_ENTRY_SIZE] = { 0x8b, 0x8b, /* movl offset(%ebx), %ecx */ 0, 0, 0, 0, /* replaced with offset of this symbol in .got. */ 0x83, 0xe1, 0xe0, /* andl $NACLMASK, %ecx */ 0xff, 0xe1, /* jmp *%ecx */ /* Pad to the next 32-byte boundary with nop instructions. */ 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, /* Lazy GOT entries point here (32-byte aligned). */ 0x68, /* pushl immediate */ 0, 0, 0, 0, /* replaced with offset into relocation table. */ 0xe9, /* jmp relative */ 0, 0, 0, 0, /* replaced with offset to start of .plt. */ /* Pad to the next 32-byte boundary with nop instructions. */ 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90 }; static const bfd_byte elf_i386_nacl_eh_frame_plt[] = { #if (PLT_CIE_LENGTH != 20 \ || PLT_FDE_LENGTH != 36 \ || PLT_FDE_START_OFFSET != 4 + PLT_CIE_LENGTH + 8 \ || PLT_FDE_LEN_OFFSET != 4 + PLT_CIE_LENGTH + 12) # error "Need elf_i386_backend_data parameters for eh_frame_plt offsets!" #endif PLT_CIE_LENGTH, 0, 0, 0, /* CIE length */ 0, 0, 0, 0, /* CIE ID */ 1, /* CIE version */ 'z', 'R', 0, /* Augmentation string */ 1, /* Code alignment factor */ 0x7c, /* Data alignment factor: -4 */ 8, /* Return address column */ 1, /* Augmentation size */ DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding */ DW_CFA_def_cfa, 4, 4, /* DW_CFA_def_cfa: r4 (esp) ofs 4 */ DW_CFA_offset + 8, 1, /* DW_CFA_offset: r8 (eip) at cfa-4 */ DW_CFA_nop, DW_CFA_nop, PLT_FDE_LENGTH, 0, 0, 0, /* FDE length */ PLT_CIE_LENGTH + 8, 0, 0, 0, /* CIE pointer */ 0, 0, 0, 0, /* R_386_PC32 .plt goes here */ 0, 0, 0, 0, /* .plt size goes here */ 0, /* Augmentation size */ DW_CFA_def_cfa_offset, 8, /* DW_CFA_def_cfa_offset: 8 */ DW_CFA_advance_loc + 6, /* DW_CFA_advance_loc: 6 to __PLT__+6 */ DW_CFA_def_cfa_offset, 12, /* DW_CFA_def_cfa_offset: 12 */ DW_CFA_advance_loc + 58, /* DW_CFA_advance_loc: 58 to __PLT__+64 */ DW_CFA_def_cfa_expression, /* DW_CFA_def_cfa_expression */ 13, /* Block length */ DW_OP_breg4, 4, /* DW_OP_breg4 (esp): 4 */ DW_OP_breg8, 0, /* DW_OP_breg8 (eip): 0 */ DW_OP_const1u, 63, DW_OP_and, DW_OP_const1u, 37, DW_OP_ge, DW_OP_lit2, DW_OP_shl, DW_OP_plus, DW_CFA_nop, DW_CFA_nop }; static const struct elf_i386_plt_layout elf_i386_nacl_plt = { elf_i386_nacl_plt0_entry, /* plt0_entry */ sizeof (elf_i386_nacl_plt0_entry), /* plt0_entry_size */ 2, /* plt0_got1_offset */ 8, /* plt0_got2_offset */ elf_i386_nacl_plt_entry, /* plt_entry */ NACL_PLT_ENTRY_SIZE, /* plt_entry_size */ 2, /* plt_got_offset */ 33, /* plt_reloc_offset */ 38, /* plt_plt_offset */ 32, /* plt_lazy_offset */ elf_i386_nacl_pic_plt0_entry, /* pic_plt0_entry */ elf_i386_nacl_pic_plt_entry, /* pic_plt_entry */ elf_i386_nacl_eh_frame_plt, /* eh_frame_plt */ sizeof (elf_i386_nacl_eh_frame_plt),/* eh_frame_plt_size */ }; static const struct elf_i386_backend_data elf_i386_nacl_arch_bed = { &elf_i386_nacl_plt, /* plt */ 0x90, /* plt0_pad_byte: nop insn */ 0, /* is_vxworks */ }; #undef elf_backend_arch_data #define elf_backend_arch_data &elf_i386_nacl_arch_bed #include "elf32-target.h" /* VxWorks support. */ #undef TARGET_LITTLE_SYM #define TARGET_LITTLE_SYM bfd_elf32_i386_vxworks_vec #undef TARGET_LITTLE_NAME #define TARGET_LITTLE_NAME "elf32-i386-vxworks" #undef ELF_OSABI #undef elf_backend_plt_alignment #define elf_backend_plt_alignment 4 static const struct elf_i386_backend_data elf_i386_vxworks_arch_bed = { &elf_i386_plt, /* plt */ 0x90, /* plt0_pad_byte */ 1, /* is_vxworks */ }; #undef elf_backend_arch_data #define elf_backend_arch_data &elf_i386_vxworks_arch_bed #undef elf_backend_relocs_compatible #undef elf_backend_post_process_headers #undef elf_backend_add_symbol_hook #define elf_backend_add_symbol_hook \ elf_vxworks_add_symbol_hook #undef elf_backend_link_output_symbol_hook #define elf_backend_link_output_symbol_hook \ elf_vxworks_link_output_symbol_hook #undef elf_backend_emit_relocs #define elf_backend_emit_relocs elf_vxworks_emit_relocs #undef elf_backend_final_write_processing #define elf_backend_final_write_processing \ elf_vxworks_final_write_processing #undef elf_backend_static_tls_alignment /* On VxWorks, we emit relocations against _PROCEDURE_LINKAGE_TABLE_, so define it. */ #undef elf_backend_want_plt_sym #define elf_backend_want_plt_sym 1 #undef elf32_bed #define elf32_bed elf32_i386_vxworks_bed #include "elf32-target.h"
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