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/* IBM S/390-specific support for 64-bit ELF Copyright 2000, 2001 Free Software Foundation, Inc. Contributed Martin Schwidefsky (schwidefsky@de.ibm.com). 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 2 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "bfd.h" #include "sysdep.h" #include "bfdlink.h" #include "libbfd.h" #include "elf-bfd.h" static reloc_howto_type *elf_s390_reloc_type_lookup PARAMS ((bfd *, bfd_reloc_code_real_type)); static void elf_s390_info_to_howto PARAMS ((bfd *, arelent *, Elf_Internal_Rela *)); static boolean elf_s390_is_local_label_name PARAMS ((bfd *, const char *)); static struct bfd_hash_entry *elf_s390_link_hash_newfunc PARAMS ((struct bfd_hash_entry *, struct bfd_hash_table *, const char *)); static struct bfd_link_hash_table *elf_s390_link_hash_table_create PARAMS ((bfd *)); static boolean elf_s390_check_relocs PARAMS ((bfd *, struct bfd_link_info *, asection *, const Elf_Internal_Rela *)); static boolean elf_s390_adjust_dynamic_symbol PARAMS ((struct bfd_link_info *, struct elf_link_hash_entry *)); static boolean elf_s390_size_dynamic_sections PARAMS ((bfd *, struct bfd_link_info *)); static boolean elf_s390_relocate_section PARAMS ((bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *, Elf_Internal_Rela *, Elf_Internal_Sym *, asection **)); static boolean elf_s390_finish_dynamic_symbol PARAMS ((bfd *, struct bfd_link_info *, struct elf_link_hash_entry *, Elf_Internal_Sym *)); static boolean elf_s390_finish_dynamic_sections PARAMS ((bfd *, struct bfd_link_info *)); #define USE_RELA 1 /* We want RELA relocations, not REL. */ #include "elf/s390.h" /* In case we're on a 32-bit machine, construct a 64-bit "-1" value from smaller values. Start with zero, widen, *then* decrement. */ #define MINUS_ONE (((bfd_vma)0) - 1) /* The relocation "howto" table. */ static reloc_howto_type elf_howto_table[] = { HOWTO (R_390_NONE, /* type */ 0, /* rightshift */ 0, /* size (0 = byte, 1 = short, 2 = long) */ 0, /* bitsize */ false, /* pc_relative */ 0, /* bitpos */ complain_overflow_dont, /* complain_on_overflow */ bfd_elf_generic_reloc, /* special_function */ "R_390_NONE", /* name */ false, /* partial_inplace */ 0, /* src_mask */ 0, /* dst_mask */ false), /* pcrel_offset */ HOWTO(R_390_8, 0, 0, 8, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_8", false, 0,0x000000ff, false), HOWTO(R_390_12, 0, 1, 12, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_390_12", false, 0,0x00000fff, false), HOWTO(R_390_16, 0, 1, 16, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_16", false, 0,0x0000ffff, false), HOWTO(R_390_32, 0, 2, 32, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_32", false, 0,0xffffffff, false), HOWTO(R_390_PC32, 0, 2, 32, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_PC32", false, 0,0xffffffff, true), HOWTO(R_390_GOT12, 0, 1, 12, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_390_GOT12", false, 0,0x00000fff, false), HOWTO(R_390_GOT32, 0, 2, 32, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_GOT32", false, 0,0xffffffff, false), HOWTO(R_390_PLT32, 0, 2, 32, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_PLT32", false, 0,0xffffffff, true), HOWTO(R_390_COPY, 0, 4, 64, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_COPY", false, 0,MINUS_ONE, false), HOWTO(R_390_GLOB_DAT, 0, 4, 64, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_GLOB_DAT",false, 0,MINUS_ONE, false), HOWTO(R_390_JMP_SLOT, 0, 4, 64, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_JMP_SLOT",false, 0,MINUS_ONE, false), HOWTO(R_390_RELATIVE, 0, 4, 64, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_RELATIVE",false, 0,MINUS_ONE, false), HOWTO(R_390_GOTOFF, 0, 4, 64, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_GOTOFF", false, 0,MINUS_ONE, false), HOWTO(R_390_GOTPC, 0, 4, 64, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_GOTPC", false, 0,MINUS_ONE, true), HOWTO(R_390_GOT16, 0, 1, 16, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_GOT16", false, 0,0x0000ffff, false), HOWTO(R_390_PC16, 0, 1, 16, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_PC16", false, 0,0x0000ffff, true), HOWTO(R_390_PC16DBL, 1, 1, 16, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_PC16DBL", false, 0,0x0000ffff, true), HOWTO(R_390_PLT16DBL, 1, 1, 16, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_PLT16DBL", false, 0,0x0000ffff, true), HOWTO(R_390_PC32DBL, 1, 2, 32, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_PC32DBL", false, 0,0xffffffff, true), HOWTO(R_390_PLT32DBL, 1, 2, 32, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_PLT32DBL", false, 0,0xffffffff, true), HOWTO(R_390_GOTPCDBL, 1, 2, 32, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_GOTPCDBL", false, 0,MINUS_ONE, true), HOWTO(R_390_64, 0, 4, 64, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_64", false, 0,MINUS_ONE, false), HOWTO(R_390_PC64, 0, 4, 64, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_PC64", false, 0,MINUS_ONE, true), HOWTO(R_390_GOT64, 0, 4, 64, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_GOT64", false, 0,MINUS_ONE, false), HOWTO(R_390_PLT64, 0, 4, 64, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_PLT64", false, 0,MINUS_ONE, true), HOWTO(R_390_GOTENT, 1, 2, 32, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_390_GOTENT", false, 0,MINUS_ONE, true), }; /* GNU extension to record C++ vtable hierarchy. */ static reloc_howto_type elf64_s390_vtinherit_howto = HOWTO (R_390_GNU_VTINHERIT, 0,4,0,false,0,complain_overflow_dont, NULL, "R_390_GNU_VTINHERIT", false,0, 0, false); static reloc_howto_type elf64_s390_vtentry_howto = HOWTO (R_390_GNU_VTENTRY, 0,4,0,false,0,complain_overflow_dont, _bfd_elf_rel_vtable_reloc_fn,"R_390_GNU_VTENTRY", false,0,0, false); static reloc_howto_type * elf_s390_reloc_type_lookup (abfd, code) bfd *abfd ATTRIBUTE_UNUSED; bfd_reloc_code_real_type code; { switch (code) { case BFD_RELOC_NONE: return &elf_howto_table[(int) R_390_NONE]; case BFD_RELOC_8: return &elf_howto_table[(int) R_390_8]; case BFD_RELOC_390_12: return &elf_howto_table[(int) R_390_12]; case BFD_RELOC_16: return &elf_howto_table[(int) R_390_16]; case BFD_RELOC_32: return &elf_howto_table[(int) R_390_32]; case BFD_RELOC_CTOR: return &elf_howto_table[(int) R_390_32]; case BFD_RELOC_32_PCREL: return &elf_howto_table[(int) R_390_PC32]; case BFD_RELOC_390_GOT12: return &elf_howto_table[(int) R_390_GOT12]; case BFD_RELOC_32_GOT_PCREL: return &elf_howto_table[(int) R_390_GOT32]; case BFD_RELOC_390_PLT32: return &elf_howto_table[(int) R_390_PLT32]; case BFD_RELOC_390_COPY: return &elf_howto_table[(int) R_390_COPY]; case BFD_RELOC_390_GLOB_DAT: return &elf_howto_table[(int) R_390_GLOB_DAT]; case BFD_RELOC_390_JMP_SLOT: return &elf_howto_table[(int) R_390_JMP_SLOT]; case BFD_RELOC_390_RELATIVE: return &elf_howto_table[(int) R_390_RELATIVE]; case BFD_RELOC_32_GOTOFF: return &elf_howto_table[(int) R_390_GOTOFF]; case BFD_RELOC_390_GOTPC: return &elf_howto_table[(int) R_390_GOTPC]; case BFD_RELOC_390_GOT16: return &elf_howto_table[(int) R_390_GOT16]; case BFD_RELOC_16_PCREL: return &elf_howto_table[(int) R_390_PC16]; case BFD_RELOC_390_PC16DBL: return &elf_howto_table[(int) R_390_PC16DBL]; case BFD_RELOC_390_PLT16DBL: return &elf_howto_table[(int) R_390_PLT16DBL]; case BFD_RELOC_VTABLE_INHERIT: return &elf64_s390_vtinherit_howto; case BFD_RELOC_VTABLE_ENTRY: return &elf64_s390_vtentry_howto; case BFD_RELOC_390_PC32DBL: return &elf_howto_table[(int) R_390_PC32DBL]; case BFD_RELOC_390_PLT32DBL: return &elf_howto_table[(int) R_390_PLT32DBL]; case BFD_RELOC_390_GOTPCDBL: return &elf_howto_table[(int) R_390_GOTPCDBL]; case BFD_RELOC_64: return &elf_howto_table[(int) R_390_64]; case BFD_RELOC_64_PCREL: return &elf_howto_table[(int) R_390_PC64]; case BFD_RELOC_390_GOT64: return &elf_howto_table[(int) R_390_GOT64]; case BFD_RELOC_390_PLT64: return &elf_howto_table[(int) R_390_PLT64]; case BFD_RELOC_390_GOTENT: return &elf_howto_table[(int) R_390_GOTENT]; default: break; } return 0; } /* We need to use ELF64_R_TYPE so we have our own copy of this function, and elf64-s390.c has its own copy. */ static void elf_s390_info_to_howto (abfd, cache_ptr, dst) bfd *abfd ATTRIBUTE_UNUSED; arelent *cache_ptr; Elf_Internal_Rela *dst; { switch (ELF64_R_TYPE(dst->r_info)) { case R_390_GNU_VTINHERIT: cache_ptr->howto = &elf64_s390_vtinherit_howto; break; case R_390_GNU_VTENTRY: cache_ptr->howto = &elf64_s390_vtentry_howto; break; default: BFD_ASSERT (ELF64_R_TYPE(dst->r_info) < (unsigned int) R_390_max); cache_ptr->howto = &elf_howto_table[ELF64_R_TYPE(dst->r_info)]; } } static boolean elf_s390_is_local_label_name (abfd, name) bfd *abfd; const char *name; { if (name[0] == '.' && (name[1] == 'X' || name[1] == 'L')) return true; return _bfd_elf_is_local_label_name (abfd, name); } /* Functions for the 390 ELF linker. */ /* The name of the dynamic interpreter. This is put in the .interp section. */ #define ELF_DYNAMIC_INTERPRETER "/usr/lib/ld.so.1" /* The nop opcode we use. */ #define s390_NOP 0x07070707 /* The size in bytes of the first entry in the procedure linkage table. */ #define PLT_FIRST_ENTRY_SIZE 32 /* The size in bytes of an entry in the procedure linkage table. */ #define PLT_ENTRY_SIZE 32 #define GOT_ENTRY_SIZE 8 /* The first three entries in a procedure linkage table are reserved, and the initial contents are unimportant (we zero them out). Subsequent entries look like this. See the SVR4 ABI 386 supplement to see how this works. */ /* For the s390, simple addr offset can only be 0 - 4096. To use the full 16777216 TB address space, several instructions are needed to load an address in a register and execute a branch( or just saving the address) Furthermore, only r 0 and 1 are free to use!!! */ /* The first 3 words in the GOT are then reserved. Word 0 is the address of the dynamic table. Word 1 is a pointer to a structure describing the object Word 2 is used to point to the loader entry address. The code for PLT entries looks like this: The GOT holds the address in the PLT to be executed. The loader then gets: 24(15) = Pointer to the structure describing the object. 28(15) = Offset in symbol table The loader must then find the module where the function is and insert the address in the GOT. PLT1: LARL 1,<fn>@GOTENT # 6 bytes Load address of GOT entry in r1 LG 1,0(1) # 6 bytes Load address from GOT in r1 BCR 15,1 # 2 bytes Jump to address RET1: BASR 1,0 # 2 bytes Return from GOT 1st time LGF 1,12(1) # 6 bytes Load offset in symbl table in r1 BRCL 15,-x # 6 bytes Jump to start of PLT .long ? # 4 bytes offset into symbol table Total = 32 bytes per PLT entry Fixup at offset 2: relative address to GOT entry Fixup at offset 22: relative branch to PLT0 Fixup at offset 28: 32 bit offset into symbol table A 32 bit offset into the symbol table is enough. It allows for symbol tables up to a size of 2 gigabyte. A single dynamic object (the main program, any shared library) is limited to 4GB in size and I want to see the program that manages to have a symbol table of more than 2 GB with a total size of at max 4 GB. */ #define PLT_ENTRY_WORD0 0xc0100000 #define PLT_ENTRY_WORD1 0x0000e310 #define PLT_ENTRY_WORD2 0x10000004 #define PLT_ENTRY_WORD3 0x07f10d10 #define PLT_ENTRY_WORD4 0xe310100c #define PLT_ENTRY_WORD5 0x0014c0f4 #define PLT_ENTRY_WORD6 0x00000000 #define PLT_ENTRY_WORD7 0x00000000 /* The first PLT entry pushes the offset into the symbol table from R1 onto the stack at 8(15) and the loader object info at 12(15), loads the loader address in R1 and jumps to it. */ /* The first entry in the PLT: PLT0: STG 1,56(15) # r1 contains the offset into the symbol table LARL 1,_GLOBAL_OFFSET_TABLE # load address of global offset table MVC 48(8,15),8(1) # move loader ino (object struct address) to stack LG 1,16(1) # get entry address of loader BCR 15,1 # jump to loader Fixup at offset 8: relative address to start of GOT. */ #define PLT_FIRST_ENTRY_WORD0 0xe310f038 #define PLT_FIRST_ENTRY_WORD1 0x0024c010 #define PLT_FIRST_ENTRY_WORD2 0x00000000 #define PLT_FIRST_ENTRY_WORD3 0xd207f030 #define PLT_FIRST_ENTRY_WORD4 0x1008e310 #define PLT_FIRST_ENTRY_WORD5 0x10100004 #define PLT_FIRST_ENTRY_WORD6 0x07f10700 #define PLT_FIRST_ENTRY_WORD7 0x07000700 /* The s390 linker needs to keep track of the number of relocs that it decides to copy in check_relocs for each symbol. This is so that it can discard PC relative relocs if it doesn't need them when linking with -Bsymbolic. We store the information in a field extending the regular ELF linker hash table. */ /* This structure keeps track of the number of PC relative relocs we have copied for a given symbol. */ struct elf_s390_pcrel_relocs_copied { /* Next section. */ struct elf_s390_pcrel_relocs_copied *next; /* A section in dynobj. */ asection *section; /* Number of relocs copied in this section. */ bfd_size_type count; }; /* s390 ELF linker hash entry. */ struct elf_s390_link_hash_entry { struct elf_link_hash_entry root; /* Number of PC relative relocs copied for this symbol. */ struct elf_s390_pcrel_relocs_copied *pcrel_relocs_copied; }; /* s390 ELF linker hash table. */ struct elf_s390_link_hash_table { struct elf_link_hash_table root; }; /* Declare this now that the above structures are defined. */ static boolean elf_s390_discard_copies PARAMS ((struct elf_s390_link_hash_entry *, PTR)); /* Traverse an s390 ELF linker hash table. */ #define elf_s390_link_hash_traverse(table, func, info) \ (elf_link_hash_traverse \ (&(table)->root, \ (boolean (*) PARAMS ((struct elf_link_hash_entry *, PTR))) (func), \ (info))) /* Get the s390 ELF linker hash table from a link_info structure. */ #define elf_s390_hash_table(p) \ ((struct elf_s390_link_hash_table *) ((p)->hash)) /* Create an entry in an s390 ELF linker hash table. */ static struct bfd_hash_entry * elf_s390_link_hash_newfunc (entry, table, string) struct bfd_hash_entry *entry; struct bfd_hash_table *table; const char *string; { struct elf_s390_link_hash_entry *ret = (struct elf_s390_link_hash_entry *) entry; /* Allocate the structure if it has not already been allocated by a subclass. */ if (ret == (struct elf_s390_link_hash_entry *) NULL) ret = ((struct elf_s390_link_hash_entry *) bfd_hash_allocate (table, sizeof (struct elf_s390_link_hash_entry))); if (ret == (struct elf_s390_link_hash_entry *) NULL) return (struct bfd_hash_entry *) ret; /* Call the allocation method of the superclass. */ ret = ((struct elf_s390_link_hash_entry *) _bfd_elf_link_hash_newfunc ((struct bfd_hash_entry *) ret, table, string)); if (ret != (struct elf_s390_link_hash_entry *) NULL) { ret->pcrel_relocs_copied = NULL; } return (struct bfd_hash_entry *) ret; } /* Create an s390 ELF linker hash table. */ static struct bfd_link_hash_table * elf_s390_link_hash_table_create (abfd) bfd *abfd; { struct elf_s390_link_hash_table *ret; ret = ((struct elf_s390_link_hash_table *) bfd_alloc (abfd, sizeof (struct elf_s390_link_hash_table))); if (ret == (struct elf_s390_link_hash_table *) NULL) return NULL; if (! _bfd_elf_link_hash_table_init (&ret->root, abfd, elf_s390_link_hash_newfunc)) { bfd_release (abfd, ret); return NULL; } return &ret->root.root; } /* Look through the relocs for a section during the first phase, and allocate space in the global offset table or procedure linkage table. */ static boolean elf_s390_check_relocs (abfd, info, sec, relocs) bfd *abfd; struct bfd_link_info *info; asection *sec; const Elf_Internal_Rela *relocs; { bfd *dynobj; Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes; bfd_signed_vma *local_got_refcounts; const Elf_Internal_Rela *rel; const Elf_Internal_Rela *rel_end; asection *sgot; asection *srelgot; asection *sreloc; if (info->relocateable) return true; dynobj = elf_hash_table (info)->dynobj; symtab_hdr = &elf_tdata (abfd)->symtab_hdr; sym_hashes = elf_sym_hashes (abfd); local_got_refcounts = elf_local_got_offsets (abfd); sgot = NULL; srelgot = NULL; sreloc = NULL; rel_end = relocs + sec->reloc_count; for (rel = relocs; rel < rel_end; rel++) { unsigned long r_symndx; struct elf_link_hash_entry *h; r_symndx = ELF64_R_SYM (rel->r_info); if (r_symndx < symtab_hdr->sh_info) h = NULL; else h = sym_hashes[r_symndx - symtab_hdr->sh_info]; /* Some relocs require a global offset table. */ if (dynobj == NULL) { switch (ELF64_R_TYPE (rel->r_info)) { case R_390_GOT12: case R_390_GOT16: case R_390_GOT32: case R_390_GOT64: case R_390_GOTOFF: case R_390_GOTPC: case R_390_GOTPCDBL: case R_390_GOTENT: elf_hash_table (info)->dynobj = dynobj = abfd; if (! _bfd_elf_create_got_section (dynobj, info)) return false; break; default: break; } } switch (ELF64_R_TYPE (rel->r_info)) { case R_390_GOT12: case R_390_GOT16: case R_390_GOT32: case R_390_GOT64: case R_390_GOTENT: /* This symbol requires a global offset table entry. */ if (sgot == NULL) { sgot = bfd_get_section_by_name (dynobj, ".got"); BFD_ASSERT (sgot != NULL); } if (srelgot == NULL && (h != NULL || info->shared)) { srelgot = bfd_get_section_by_name (dynobj, ".rela.got"); if (srelgot == NULL) { srelgot = bfd_make_section (dynobj, ".rela.got"); if (srelgot == NULL || ! bfd_set_section_flags (dynobj, srelgot, (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS | SEC_IN_MEMORY | SEC_LINKER_CREATED | SEC_READONLY)) || ! bfd_set_section_alignment (dynobj, srelgot, 2)) return false; } } if (h != NULL) { if (h->got.refcount == -1) { h->got.refcount = 1; /* Make sure this symbol is output as a dynamic symbol. */ if (h->dynindx == -1) { if (! bfd_elf64_link_record_dynamic_symbol (info, h)) return false; } sgot->_raw_size += 8; srelgot->_raw_size += sizeof (Elf64_External_Rela); } else h->got.refcount += 1; } else { /* This is a global offset table entry for a local symbol. */ if (local_got_refcounts == NULL) { size_t size; size = symtab_hdr->sh_info * sizeof (bfd_vma); local_got_refcounts = (bfd_signed_vma *) bfd_alloc (abfd, size); if (local_got_refcounts == NULL) return false; elf_local_got_refcounts (abfd) = local_got_refcounts; memset (local_got_refcounts, -1, size); } if (local_got_refcounts[r_symndx] == -1) { local_got_refcounts[r_symndx] = 1; sgot->_raw_size += 8; if (info->shared) { /* If we are generating a shared object, we need to output a R_390_RELATIVE reloc so that the dynamic linker can adjust this GOT entry. */ srelgot->_raw_size += sizeof (Elf64_External_Rela); } } else local_got_refcounts[r_symndx] += 1; } break; case R_390_PLT16DBL: case R_390_PLT32: case R_390_PLT32DBL: case R_390_PLT64: /* 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; if (h->plt.refcount == -1) { h->plt.refcount = 1; h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_PLT; } else h->plt.refcount += 1; break; case R_390_8: case R_390_16: case R_390_32: case R_390_64: case R_390_PC16: case R_390_PC16DBL: case R_390_PC32: case R_390_PC32DBL: case R_390_PC64: if (h != NULL) h->elf_link_hash_flags |= ELF_LINK_NON_GOT_REF; /* 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). We account for that possibility below by storing information in the pcrel_relocs_copied field of the hash table entry. */ if (info->shared && (sec->flags & SEC_ALLOC) != 0 && (ELF64_R_TYPE (rel->r_info) == R_390_8 || ELF64_R_TYPE (rel->r_info) == R_390_16 || ELF64_R_TYPE (rel->r_info) == R_390_32 || ELF64_R_TYPE (rel->r_info) == R_390_64 || (h != NULL && h->dynindx != -1 && (! info->symbolic || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)))) { /* When creating a shared object, we must copy these reloc types into the output file. We create a reloc section in dynobj and make room for this reloc. */ if (sreloc == NULL) { const char *name; name = (bfd_elf_string_from_elf_section (abfd, elf_elfheader (abfd)->e_shstrndx, elf_section_data (sec)->rel_hdr.sh_name)); if (name == NULL) return false; BFD_ASSERT (strncmp (name, ".rela", 5) == 0 && strcmp (bfd_get_section_name (abfd, sec), name + 5) == 0); sreloc = bfd_get_section_by_name (dynobj, name); if (sreloc == NULL) { flagword flags; sreloc = bfd_make_section (dynobj, name); flags = (SEC_HAS_CONTENTS | SEC_READONLY | SEC_IN_MEMORY | SEC_LINKER_CREATED); if ((sec->flags & SEC_ALLOC) != 0) flags |= SEC_ALLOC | SEC_LOAD; if (sreloc == NULL || ! bfd_set_section_flags (dynobj, sreloc, flags) || ! bfd_set_section_alignment (dynobj, sreloc, 2)) return false; } } sreloc->_raw_size += sizeof (Elf64_External_Rela); /* If we are linking with -Bsymbolic, and this is a global symbol, we count the number of PC relative relocations we have entered for this symbol, so that we can discard them again if the symbol is later defined by a regular object. Note that this function is only called if we are using an elf64_s390 linker hash table, which means that h is really a pointer to an elf64_s390_link_hash_entry. */ if (h != NULL && (ELF64_R_TYPE (rel->r_info) == R_390_PC16 || ELF64_R_TYPE (rel->r_info) == R_390_PC16DBL || ELF64_R_TYPE (rel->r_info) == R_390_PC32 || ELF64_R_TYPE (rel->r_info) == R_390_PC32DBL || ELF64_R_TYPE (rel->r_info) == R_390_PC64)) { struct elf_s390_link_hash_entry *eh; struct elf_s390_pcrel_relocs_copied *p; eh = (struct elf_s390_link_hash_entry *) h; for (p = eh->pcrel_relocs_copied; p != NULL; p = p->next) if (p->section == sreloc) break; if (p == NULL) { p = ((struct elf_s390_pcrel_relocs_copied *) bfd_alloc (dynobj, sizeof *p)); if (p == NULL) return false; p->next = eh->pcrel_relocs_copied; eh->pcrel_relocs_copied = p; p->section = sreloc; p->count = 0; } ++p->count; } } break; /* This relocation describes the C++ object vtable hierarchy. Reconstruct it for later use during GC. */ case R_390_GNU_VTINHERIT: if (!_bfd_elf64_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_390_GNU_VTENTRY: if (!_bfd_elf64_gc_record_vtentry (abfd, sec, h, rel->r_addend)) return false; break; default: break; } } return true; } /* Return the section that should be marked against GC for a given relocation. */ static asection * elf_s390_gc_mark_hook (abfd, info, rel, h, sym) bfd *abfd; struct bfd_link_info *info ATTRIBUTE_UNUSED; Elf_Internal_Rela *rel; struct elf_link_hash_entry *h; Elf_Internal_Sym *sym; { if (h != NULL) { switch (ELF64_R_TYPE (rel->r_info)) { case R_390_GNU_VTINHERIT: case R_390_GNU_VTENTRY: break; default: switch (h->root.type) { case bfd_link_hash_defined: case bfd_link_hash_defweak: return h->root.u.def.section; case bfd_link_hash_common: return h->root.u.c.p->section; default: break; } } } else { if (!(elf_bad_symtab (abfd) && ELF_ST_BIND (sym->st_info) != STB_LOCAL) && ! ((sym->st_shndx <= 0 || sym->st_shndx >= SHN_LORESERVE) && sym->st_shndx != SHN_COMMON)) { return bfd_section_from_elf_index (abfd, sym->st_shndx); } } return NULL; } /* Update the got entry reference counts for the section being removed. */ static boolean elf_s390_gc_sweep_hook (abfd, info, sec, relocs) bfd *abfd ATTRIBUTE_UNUSED; struct bfd_link_info *info ATTRIBUTE_UNUSED; asection *sec ATTRIBUTE_UNUSED; const Elf_Internal_Rela *relocs ATTRIBUTE_UNUSED; { Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes; bfd_signed_vma *local_got_refcounts; const Elf_Internal_Rela *rel, *relend; unsigned long r_symndx; struct elf_link_hash_entry *h; bfd *dynobj; asection *sgot; asection *srelgot; symtab_hdr = &elf_tdata (abfd)->symtab_hdr; sym_hashes = elf_sym_hashes (abfd); local_got_refcounts = elf_local_got_refcounts (abfd); dynobj = elf_hash_table (info)->dynobj; if (dynobj == NULL) return true; sgot = bfd_get_section_by_name (dynobj, ".got"); srelgot = bfd_get_section_by_name (dynobj, ".rela.got"); relend = relocs + sec->reloc_count; for (rel = relocs; rel < relend; rel++) switch (ELF64_R_TYPE (rel->r_info)) { case R_390_GOT12: case R_390_GOT16: case R_390_GOT32: case R_390_GOT64: case R_390_GOTOFF: case R_390_GOTPC: case R_390_GOTPCDBL: case R_390_GOTENT: r_symndx = ELF64_R_SYM (rel->r_info); if (r_symndx >= symtab_hdr->sh_info) { h = sym_hashes[r_symndx - symtab_hdr->sh_info]; if (h->got.refcount > 0) { h->got.refcount -= 1; if (h->got.refcount == 0) { sgot->_raw_size -= 8; srelgot->_raw_size -= sizeof (Elf64_External_Rela); } } } else if (local_got_refcounts != NULL) { if (local_got_refcounts[r_symndx] > 0) { local_got_refcounts[r_symndx] -= 1; if (local_got_refcounts[r_symndx] == 0) { sgot->_raw_size -= 8; if (info->shared) srelgot->_raw_size -= sizeof (Elf64_External_Rela); } } } break; case R_390_PLT16DBL: case R_390_PLT32: case R_390_PLT32DBL: case R_390_PLT64: r_symndx = ELF64_R_SYM (rel->r_info); if (r_symndx >= symtab_hdr->sh_info) { h = sym_hashes[r_symndx - symtab_hdr->sh_info]; 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 boolean elf_s390_adjust_dynamic_symbol (info, h) struct bfd_link_info *info; struct elf_link_hash_entry *h; { bfd *dynobj; asection *s; unsigned int power_of_two; dynobj = elf_hash_table (info)->dynobj; /* Make sure we know what is going on here. */ BFD_ASSERT (dynobj != NULL && ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) || h->weakdef != NULL || ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0))); /* If this is a function, put it in the procedure linkage table. We will fill in the contents of the procedure linkage table later (although we could actually do it here). */ if (h->type == STT_FUNC || (h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0) { if ((! info->shared && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0 && (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) == 0) || (info->shared && h->plt.refcount <= 0)) { /* 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. 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->elf_link_hash_flags &= ~ELF_LINK_HASH_NEEDS_PLT; return true; } /* Make sure this symbol is output as a dynamic symbol. */ if (h->dynindx == -1) { if (! bfd_elf64_link_record_dynamic_symbol (info, h)) return false; } s = bfd_get_section_by_name (dynobj, ".plt"); BFD_ASSERT (s != NULL); /* The first entry in .plt is reserved. */ if (s->_raw_size == 0) s->_raw_size = PLT_FIRST_ENTRY_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->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) { h->root.u.def.section = s; h->root.u.def.value = s->_raw_size; } h->plt.offset = s->_raw_size; /* Make room for this entry. */ s->_raw_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. */ s = bfd_get_section_by_name (dynobj, ".got.plt"); BFD_ASSERT (s != NULL); s->_raw_size += GOT_ENTRY_SIZE; /* We also need to make an entry in the .rela.plt section. */ s = bfd_get_section_by_name (dynobj, ".rela.plt"); BFD_ASSERT (s != NULL); s->_raw_size += sizeof (Elf64_External_Rela); return true; } /* 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->weakdef != NULL) { BFD_ASSERT (h->weakdef->root.type == bfd_link_hash_defined || h->weakdef->root.type == bfd_link_hash_defweak); h->root.u.def.section = h->weakdef->root.u.def.section; h->root.u.def.value = h->weakdef->root.u.def.value; 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->elf_link_hash_flags & ELF_LINK_NON_GOT_REF) == 0) 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. */ s = bfd_get_section_by_name (dynobj, ".dynbss"); BFD_ASSERT (s != NULL); /* We must generate a R_390_COPY reloc to tell the dynamic linker to copy the initial value out of the dynamic object and into the runtime process image. We need to remember the offset into the .rel.bss section we are going to use. */ if ((h->root.u.def.section->flags & SEC_ALLOC) != 0) { asection *srel; srel = bfd_get_section_by_name (dynobj, ".rela.bss"); BFD_ASSERT (srel != NULL); srel->_raw_size += sizeof (Elf64_External_Rela); h->elf_link_hash_flags |= ELF_LINK_HASH_NEEDS_COPY; } /* We need to figure out the alignment required for this symbol. I have no idea how ELF linkers handle this. */ power_of_two = bfd_log2 (h->size); if (power_of_two > 3) power_of_two = 3; /* Apply the required alignment. */ s->_raw_size = BFD_ALIGN (s->_raw_size, (bfd_size_type) (1 << power_of_two)); if (power_of_two > bfd_get_section_alignment (dynobj, s)) { if (! bfd_set_section_alignment (dynobj, s, power_of_two)) return false; } /* Define the symbol as being at this point in the section. */ h->root.u.def.section = s; h->root.u.def.value = s->_raw_size; /* Increment the section size to make room for the symbol. */ s->_raw_size += h->size; return true; } /* Set the sizes of the dynamic sections. */ static boolean elf_s390_size_dynamic_sections (output_bfd, info) bfd *output_bfd; struct bfd_link_info *info; { bfd *dynobj; asection *s; boolean reltext; boolean relocs; boolean plt; dynobj = elf_hash_table (info)->dynobj; BFD_ASSERT (dynobj != NULL); if (elf_hash_table (info)->dynamic_sections_created) { /* Set the contents of the .interp section to the interpreter. */ if (! info->shared) { s = bfd_get_section_by_name (dynobj, ".interp"); BFD_ASSERT (s != NULL); s->_raw_size = sizeof ELF_DYNAMIC_INTERPRETER; s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER; } } else { /* We may have created entries in the .rela.got section. However, if we are not creating the dynamic sections, we will not actually use these entries. Reset the size of .rela.got, which will cause it to get stripped from the output file below. */ s = bfd_get_section_by_name (dynobj, ".rela.got"); if (s != NULL) s->_raw_size = 0; } /* If this is a -Bsymbolic shared link, then we need to discard all PC relative relocs against symbols defined in a regular object. We allocated space for them in the check_relocs routine, but we will not fill them in in the relocate_section routine. */ if (info->shared) elf_s390_link_hash_traverse (elf_s390_hash_table (info), elf_s390_discard_copies, (PTR) info); /* The check_relocs and adjust_dynamic_symbol entry points have determined the sizes of the various dynamic sections. Allocate memory for them. */ plt = false; reltext = false; relocs = false; for (s = dynobj->sections; s != NULL; s = s->next) { const char *name; boolean strip; if ((s->flags & SEC_LINKER_CREATED) == 0) continue; /* It's OK to base decisions on the section name, because none of the dynobj section names depend upon the input files. */ name = bfd_get_section_name (dynobj, s); strip = false; if (strcmp (name, ".plt") == 0) { if (s->_raw_size == 0) { /* Strip this section if we don't need it; see the comment below. */ strip = true; } else { /* Remember whether there is a PLT. */ plt = true; } } else if (strncmp (name, ".rela", 5) == 0) { if (s->_raw_size == 0) { /* If we don't need this section, strip it from the output file. This is to handle .rela.bss and .rel.plt. We must create it in create_dynamic_sections, because it 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. */ strip = true; } else { asection *target; /* Remember whether there are any reloc sections other than .rela.plt. */ if (strcmp (name, ".rela.plt") != 0) { const char *outname; relocs = true; /* If this relocation section applies to a read only section, then we probably need a DT_TEXTREL entry. The entries in the .rela.plt section really apply to the .got section, which we created ourselves and so know is not readonly. */ outname = bfd_get_section_name (output_bfd, s->output_section); target = bfd_get_section_by_name (output_bfd, outname + 5); if (target != NULL && (target->flags & SEC_READONLY) != 0 && (target->flags & SEC_ALLOC) != 0) reltext = true; } /* We use the reloc_count field as a counter if we need to copy relocs into the output file. */ s->reloc_count = 0; } } else if (strncmp (name, ".got", 4) != 0) { /* It's not one of our sections, so don't allocate space. */ continue; } if (strip) { _bfd_strip_section_from_output (info, s); continue; } /* Allocate memory for the section contents. */ s->contents = (bfd_byte *) bfd_alloc (dynobj, s->_raw_size); if (s->contents == NULL && s->_raw_size != 0) return false; } if (elf_hash_table (info)->dynamic_sections_created) { /* Add some entries to the .dynamic section. We fill in the values later, in elf_s390_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. */ if (! info->shared) { if (! bfd_elf64_add_dynamic_entry (info, DT_DEBUG, 0)) return false; } if (plt) { if (! bfd_elf64_add_dynamic_entry (info, DT_PLTGOT, 0) || ! bfd_elf64_add_dynamic_entry (info, DT_PLTRELSZ, 0) || ! bfd_elf64_add_dynamic_entry (info, DT_PLTREL, DT_RELA) || ! bfd_elf64_add_dynamic_entry (info, DT_JMPREL, 0)) return false; } if (relocs) { if (! bfd_elf64_add_dynamic_entry (info, DT_RELA, 0) || ! bfd_elf64_add_dynamic_entry (info, DT_RELASZ, 0) || ! bfd_elf64_add_dynamic_entry (info, DT_RELAENT, sizeof (Elf64_External_Rela))) return false; } if (reltext) { if (! bfd_elf64_add_dynamic_entry (info, DT_TEXTREL, 0)) return false; info->flags |= DF_TEXTREL; } } return true; } /* This function is called via elf64_s390_link_hash_traverse if we are creating a shared object with -Bsymbolic. It discards the space allocated to copy PC relative relocs against symbols which are defined in regular objects. We allocated space for them in the check_relocs routine, but we won't fill them in in the relocate_section routine. */ /*ARGSUSED*/ static boolean elf_s390_discard_copies (h, inf) struct elf_s390_link_hash_entry *h; PTR inf; { struct elf_s390_pcrel_relocs_copied *s; struct bfd_link_info *info = (struct bfd_link_info *) inf; /* If a symbol has been forced local or we have found a regular definition for the symbolic link case, then we won't be needing any relocs. */ if ((h->root.elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0 && ((h->root.elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0 || info->symbolic)) { for (s = h->pcrel_relocs_copied; s != NULL; s = s->next) s->section->_raw_size -= s->count * sizeof (Elf64_External_Rela); } return true; } /* Relocate a 390 ELF section. */ static boolean elf_s390_relocate_section (output_bfd, info, input_bfd, input_section, contents, relocs, local_syms, local_sections) 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; { bfd *dynobj; Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes; bfd_vma *local_got_offsets; asection *sgot; asection *splt; asection *sreloc; Elf_Internal_Rela *rel; Elf_Internal_Rela *relend; dynobj = elf_hash_table (info)->dynobj; symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr; sym_hashes = elf_sym_hashes (input_bfd); local_got_offsets = elf_local_got_offsets (input_bfd); sgot = NULL; splt = NULL; sreloc = NULL; if (dynobj != NULL) { splt = bfd_get_section_by_name (dynobj, ".plt"); sgot = bfd_get_section_by_name (dynobj, ".got"); } rel = relocs; relend = relocs + input_section->reloc_count; for (; rel < relend; rel++) { int r_type; reloc_howto_type *howto; unsigned long r_symndx; struct elf_link_hash_entry *h; Elf_Internal_Sym *sym; asection *sec; bfd_vma relocation; bfd_reloc_status_type r; r_type = ELF64_R_TYPE (rel->r_info); if (r_type == R_390_GNU_VTINHERIT || r_type == R_390_GNU_VTENTRY) continue; if (r_type < 0 || r_type >= (int) R_390_max) { bfd_set_error (bfd_error_bad_value); return false; } howto = elf_howto_table + r_type; r_symndx = ELF64_R_SYM (rel->r_info); if (info->relocateable) { /* This is a relocateable link. We don't have to change anything, unless the reloc is against a section symbol, in which case we have to adjust according to where the section symbol winds up in the output section. */ if (r_symndx < symtab_hdr->sh_info) { sym = local_syms + r_symndx; if (ELF_ST_TYPE (sym->st_info) == STT_SECTION) { sec = local_sections[r_symndx]; rel->r_addend += sec->output_offset + sym->st_value; } } continue; } /* This is a final link. */ h = NULL; sym = NULL; sec = NULL; 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); } else { 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->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak) { sec = h->root.u.def.section; if ((r_type == R_390_GOTPC || r_type == R_390_GOTPCDBL) || ((r_type == R_390_PLT16DBL || r_type == R_390_PLT32 || r_type == R_390_PLT32DBL || r_type == R_390_PLT64) && splt != NULL && h->plt.offset != (bfd_vma) -1) || ((r_type == R_390_GOT12 || r_type == R_390_GOT16 || r_type == R_390_GOT32 || r_type == R_390_GOT64 || r_type == R_390_GOTENT) && elf_hash_table (info)->dynamic_sections_created && (! info->shared || (! info->symbolic && h->dynindx != -1) || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)) || (info->shared && ((! info->symbolic && h->dynindx != -1) || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) && ( r_type == R_390_8 || r_type == R_390_16 || r_type == R_390_32 || r_type == R_390_64 || r_type == R_390_PC16 || r_type == R_390_PC16DBL || r_type == R_390_PC32 || r_type == R_390_PC32DBL || r_type == R_390_PC64) && ((input_section->flags & SEC_ALLOC) != 0 /* DWARF will emit R_386_32 relocations in its sections against symbols defined externally in shared libraries. We can't do anything with them here. */ || ((input_section->flags & SEC_DEBUGGING) != 0 && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0)))) { /* In these cases, we don't need the relocation value. We check specially because in some obscure cases sec->output_section will be NULL. */ relocation = 0; } else if (sec->output_section == NULL) { (*_bfd_error_handler) (_("%s: warning: unresolvable relocation against symbol `%s' from %s section"), bfd_get_filename (input_bfd), h->root.root.string, bfd_get_section_name (input_bfd, input_section)); relocation = 0; } else relocation = (h->root.u.def.value + sec->output_section->vma + sec->output_offset); } else if (h->root.type == bfd_link_hash_undefweak) relocation = 0; else if (info->shared && !info->symbolic && !info->no_undefined && ELF_ST_VISIBILITY (h->other) == STV_DEFAULT) relocation = 0; else { if (! ((*info->callbacks->undefined_symbol) (info, h->root.root.string, input_bfd, input_section, rel->r_offset, (!info->shared || info->no_undefined || ELF_ST_VISIBILITY (h->other))))) return false; relocation = 0; } } switch (r_type) { case R_390_GOT12: case R_390_GOT16: case R_390_GOT32: case R_390_GOT64: case R_390_GOTENT: /* Relocation is to the entry for this symbol in the global offset table. */ BFD_ASSERT (sgot != NULL); if (h != NULL) { bfd_vma off; off = h->got.offset; BFD_ASSERT (off != (bfd_vma) -1); if (! elf_hash_table (info)->dynamic_sections_created || (info->shared && (info->symbolic || h->dynindx == -1) && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))) { /* 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 2, 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_64 (output_bfd, relocation, sgot->contents + off); h->got.offset |= 1; } } relocation = sgot->output_offset + off; } else { bfd_vma off; BFD_ASSERT (local_got_offsets != NULL && local_got_offsets[r_symndx] != (bfd_vma) -1); off = local_got_offsets[r_symndx]; /* The offset must always be a multiple of 8. 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_64 (output_bfd, relocation, sgot->contents + off); if (info->shared) { asection *srelgot; Elf_Internal_Rela outrel; srelgot = bfd_get_section_by_name (dynobj, ".rela.got"); BFD_ASSERT (srelgot != NULL); outrel.r_offset = (sgot->output_section->vma + sgot->output_offset + off); outrel.r_info = ELF64_R_INFO (0, R_390_RELATIVE); outrel.r_addend = relocation; bfd_elf64_swap_reloca_out (output_bfd, &outrel, (((Elf64_External_Rela *) srelgot->contents) + srelgot->reloc_count)); ++srelgot->reloc_count; } local_got_offsets[r_symndx] |= 1; } relocation = sgot->output_offset + off; } /* * For @GOTENT the relocation is against the offset between * the instruction and the symbols entry in the GOT and not * between the start of the GOT and the symbols entry. We * add the vma of the GOT to get the correct value. */ if (r_type == R_390_GOTENT) relocation += sgot->output_section->vma; break; case R_390_GOTOFF: /* Relocation is relative to the start of the global offset table. */ if (sgot == NULL) { sgot = bfd_get_section_by_name (dynobj, ".got"); BFD_ASSERT (sgot != NULL); } /* Note that sgot->output_offset is not involved in this calculation. We always want the start of .got. If we defined _GLOBAL_OFFSET_TABLE in a different way, as is permitted by the ABI, we might have to change this calculation. */ relocation -= sgot->output_section->vma; break; case R_390_GOTPC: case R_390_GOTPCDBL: /* Use global offset table as symbol value. */ if (sgot == NULL) { sgot = bfd_get_section_by_name (dynobj, ".got"); BFD_ASSERT (sgot != NULL); } relocation = sgot->output_section->vma; break; case R_390_PLT16DBL: case R_390_PLT32: case R_390_PLT32DBL: case R_390_PLT64: /* 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 || 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 = (splt->output_section->vma + splt->output_offset + h->plt.offset); break; case R_390_8: case R_390_16: case R_390_32: case R_390_64: case R_390_PC16: case R_390_PC16DBL: case R_390_PC32: case R_390_PC32DBL: case R_390_PC64: if (info->shared && (input_section->flags & SEC_ALLOC) != 0 && (r_type == R_390_8 || r_type == R_390_16 || r_type == R_390_32 || r_type == R_390_64 || (h != NULL && h->dynindx != -1 && (! info->symbolic || (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)))) { Elf_Internal_Rela outrel; boolean skip, relocate; /* When generating a shared object, these relocations are copied into the output file to be resolved at run time. */ if (sreloc == NULL) { const char *name; name = (bfd_elf_string_from_elf_section (input_bfd, elf_elfheader (input_bfd)->e_shstrndx, elf_section_data (input_section)->rel_hdr.sh_name)); if (name == NULL) return false; BFD_ASSERT (strncmp (name, ".rela", 5) == 0 && strcmp (bfd_get_section_name (input_bfd, input_section), name + 5) == 0); sreloc = bfd_get_section_by_name (dynobj, name); BFD_ASSERT (sreloc != NULL); } skip = false; if (elf_section_data (input_section)->stab_info == NULL) outrel.r_offset = rel->r_offset; else { bfd_vma off; off = (_bfd_stab_section_offset (output_bfd, &elf_hash_table (info)->stab_info, input_section, &elf_section_data (input_section)->stab_info, rel->r_offset)); if (off == (bfd_vma) -1) skip = true; outrel.r_offset = off; } outrel.r_offset += (input_section->output_section->vma + input_section->output_offset); if (skip) { memset (&outrel, 0, sizeof outrel); relocate = false; } else if (r_type == R_390_PC16 || r_type == R_390_PC16DBL || r_type == R_390_PC32 || r_type == R_390_PC32DBL || r_type == R_390_PC64) { BFD_ASSERT (h != NULL && h->dynindx != -1); relocate = false; outrel.r_info = ELF64_R_INFO (h->dynindx, r_type); outrel.r_addend = relocation + rel->r_addend; } else { /* h->dynindx may be -1 if this symbol was marked to become local. */ if (h == NULL || ((info->symbolic || h->dynindx == -1) && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)) { relocate = true; outrel.r_info = ELF64_R_INFO (0, R_390_RELATIVE); outrel.r_addend = relocation + rel->r_addend; } else { BFD_ASSERT (h->dynindx != -1); relocate = false; outrel.r_info = ELF64_R_INFO (h->dynindx, R_390_64); outrel.r_addend = relocation + rel->r_addend; } } bfd_elf64_swap_reloca_out (output_bfd, &outrel, (((Elf64_External_Rela *) sreloc->contents) + sreloc->reloc_count)); ++sreloc->reloc_count; /* 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; default: break; } r = _bfd_final_link_relocate (howto, input_bfd, input_section, contents, rel->r_offset, relocation, rel->r_addend); if (r != bfd_reloc_ok) { switch (r) { default: case bfd_reloc_outofrange: abort (); case bfd_reloc_overflow: { 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 (! ((*info->callbacks->reloc_overflow) (info, name, howto->name, (bfd_vma) 0, input_bfd, input_section, rel->r_offset))) return false; } break; } } } return true; } /* Finish up dynamic symbol handling. We set the contents of various dynamic sections here. */ static boolean elf_s390_finish_dynamic_symbol (output_bfd, info, h, sym) bfd *output_bfd; struct bfd_link_info *info; struct elf_link_hash_entry *h; Elf_Internal_Sym *sym; { bfd *dynobj; dynobj = elf_hash_table (info)->dynobj; if (h->plt.offset != (bfd_vma) -1) { asection *splt; asection *srela; Elf_Internal_Rela rela; bfd_vma got_offset; bfd_vma plt_index; asection *sgot; /* This symbol has an entry in the procedure linkage table. Set it up. */ BFD_ASSERT (h->dynindx != -1); splt = bfd_get_section_by_name (dynobj, ".plt"); sgot = bfd_get_section_by_name (dynobj, ".got.plt"); srela = bfd_get_section_by_name (dynobj, ".rela.plt"); BFD_ASSERT (splt != NULL && sgot != NULL && srela != NULL); /* Calc. index no. Current offset - size first entry / entry size. */ plt_index = (h->plt.offset - PLT_FIRST_ENTRY_SIZE) / PLT_ENTRY_SIZE; /* Offset in GOT is PLT index plus GOT headers(3) times 8, addr & GOT addr. */ got_offset = (plt_index + 3) * GOT_ENTRY_SIZE; /* Fill in the blueprint of a PLT. */ bfd_put_32 (output_bfd, PLT_ENTRY_WORD0, splt->contents + h->plt.offset); bfd_put_32 (output_bfd, PLT_ENTRY_WORD1, splt->contents + h->plt.offset + 4); bfd_put_32 (output_bfd, PLT_ENTRY_WORD2, splt->contents + h->plt.offset + 8); bfd_put_32 (output_bfd, PLT_ENTRY_WORD3, splt->contents + h->plt.offset + 12); bfd_put_32 (output_bfd, PLT_ENTRY_WORD4, splt->contents + h->plt.offset + 16); bfd_put_32 (output_bfd, PLT_ENTRY_WORD5, splt->contents + h->plt.offset + 20); bfd_put_32 (output_bfd, PLT_ENTRY_WORD6, splt->contents + h->plt.offset + 24); bfd_put_32 (output_bfd, PLT_ENTRY_WORD7, splt->contents + h->plt.offset + 28); /* Fixup the relative address to the GOT entry */ bfd_put_32 (output_bfd, (sgot->output_section->vma + sgot->output_offset + got_offset - (splt->output_section->vma + h->plt.offset))/2, splt->contents + h->plt.offset + 2); /* Fixup the relative branch to PLT 0 */ bfd_put_32 (output_bfd, - (PLT_FIRST_ENTRY_SIZE + (PLT_ENTRY_SIZE * plt_index) + 22)/2, splt->contents + h->plt.offset + 24); /* Fixup offset into symbol table */ bfd_put_32 (output_bfd, plt_index * sizeof (Elf64_External_Rela), splt->contents + h->plt.offset + 28); /* Fill in the entry in the .rela.plt section. */ rela.r_offset = (sgot->output_section->vma + sgot->output_offset + got_offset); rela.r_info = ELF64_R_INFO (h->dynindx, R_390_JMP_SLOT); rela.r_addend = 0; bfd_elf64_swap_reloca_out (output_bfd, &rela, ((Elf64_External_Rela *) srela->contents + plt_index )); /* Fill in the entry in the global offset table. Points to instruction after GOT offset. */ bfd_put_64 (output_bfd, (splt->output_section->vma + splt->output_offset + h->plt.offset + 14), sgot->contents + got_offset); if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0) { /* Mark the symbol as undefined, rather than as defined in the .plt section. Leave the value alone. */ sym->st_shndx = SHN_UNDEF; } } if (h->got.offset != (bfd_vma) -1) { asection *sgot; asection *srela; Elf_Internal_Rela rela; /* This symbol has an entry in the global offset table. Set it up. */ sgot = bfd_get_section_by_name (dynobj, ".got"); srela = bfd_get_section_by_name (dynobj, ".rela.got"); BFD_ASSERT (sgot != NULL && srela != NULL); rela.r_offset = (sgot->output_section->vma + sgot->output_offset + (h->got.offset &~ 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 (! elf_hash_table (info)->dynamic_sections_created || (info->shared && (info->symbolic || h->dynindx == -1) && (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR))) { rela.r_info = ELF64_R_INFO (0, R_390_RELATIVE); rela.r_addend = (h->root.u.def.value + h->root.u.def.section->output_section->vma + h->root.u.def.section->output_offset); } else { BFD_ASSERT((h->got.offset & 1) == 0); bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents + h->got.offset); rela.r_info = ELF64_R_INFO (h->dynindx, R_390_GLOB_DAT); rela.r_addend = 0; } bfd_elf64_swap_reloca_out (output_bfd, &rela, ((Elf64_External_Rela *) srela->contents + srela->reloc_count)); ++srela->reloc_count; } if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_COPY) != 0) { asection *s; Elf_Internal_Rela rela; /* This symbols needs a copy reloc. Set it up. */ BFD_ASSERT (h->dynindx != -1 && (h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak)); s = bfd_get_section_by_name (h->root.u.def.section->owner, ".rela.bss"); BFD_ASSERT (s != NULL); rela.r_offset = (h->root.u.def.value + h->root.u.def.section->output_section->vma + h->root.u.def.section->output_offset); rela.r_info = ELF64_R_INFO (h->dynindx, R_390_COPY); rela.r_addend = 0; bfd_elf64_swap_reloca_out (output_bfd, &rela, ((Elf64_External_Rela *) s->contents + s->reloc_count)); ++s->reloc_count; } /* Mark some specially defined symbols as absolute. */ if (strcmp (h->root.root.string, "_DYNAMIC") == 0 || strcmp (h->root.root.string, "_GLOBAL_OFFSET_TABLE_") == 0 || strcmp (h->root.root.string, "_PROCEDURE_LINKAGE_TABLE_") == 0) sym->st_shndx = SHN_ABS; return true; } /* Finish up the dynamic sections. */ static boolean elf_s390_finish_dynamic_sections (output_bfd, info) bfd *output_bfd; struct bfd_link_info *info; { bfd *dynobj; asection *sdyn; asection *sgot; dynobj = elf_hash_table (info)->dynobj; sgot = bfd_get_section_by_name (dynobj, ".got.plt"); BFD_ASSERT (sgot != NULL); sdyn = bfd_get_section_by_name (dynobj, ".dynamic"); if (elf_hash_table (info)->dynamic_sections_created) { asection *splt; Elf64_External_Dyn *dyncon, *dynconend; BFD_ASSERT (sdyn != NULL); dyncon = (Elf64_External_Dyn *) sdyn->contents; dynconend = (Elf64_External_Dyn *) (sdyn->contents + sdyn->_raw_size); for (; dyncon < dynconend; dyncon++) { Elf_Internal_Dyn dyn; const char *name; asection *s; bfd_elf64_swap_dyn_in (dynobj, dyncon, &dyn); switch (dyn.d_tag) { default: break; case DT_PLTGOT: name = ".got"; goto get_vma; case DT_JMPREL: name = ".rela.plt"; get_vma: s = bfd_get_section_by_name(output_bfd, name); BFD_ASSERT (s != NULL); dyn.d_un.d_ptr = s->vma; bfd_elf64_swap_dyn_out (output_bfd, &dyn, dyncon); break; case DT_PLTRELSZ: s = bfd_get_section_by_name (output_bfd, ".rela.plt"); BFD_ASSERT (s != NULL); if (s->_cooked_size != 0) dyn.d_un.d_val = s->_cooked_size; else dyn.d_un.d_val = s->_raw_size; bfd_elf64_swap_dyn_out (output_bfd, &dyn, dyncon); break; case DT_RELASZ: /* The procedure linkage table relocs (DT_JMPREL) should not be included in the overall relocs (DT_RELA). Therefore, we override the DT_RELASZ entry here to make it not include the JMPREL relocs. Since the linker script arranges for .rela.plt to follow all other relocation sections, we don't have to worry about changing the DT_RELA entry. */ s = bfd_get_section_by_name (output_bfd, ".rela.plt"); if (s != NULL) { if (s->_cooked_size != 0) dyn.d_un.d_val -= s->_cooked_size; else dyn.d_un.d_val -= s->_raw_size; } bfd_elf64_swap_dyn_out (output_bfd, &dyn, dyncon); break; } } /* Fill in the special first entry in the procedure linkage table. */ splt = bfd_get_section_by_name (dynobj, ".plt"); if (splt && splt->_raw_size > 0) { /* fill in blueprint for plt 0 entry */ bfd_put_32 (output_bfd, PLT_FIRST_ENTRY_WORD0, splt->contents ); bfd_put_32 (output_bfd, PLT_FIRST_ENTRY_WORD1, splt->contents +4 ); bfd_put_32 (output_bfd, PLT_FIRST_ENTRY_WORD3, splt->contents +12 ); bfd_put_32 (output_bfd, PLT_FIRST_ENTRY_WORD4, splt->contents +16 ); bfd_put_32 (output_bfd, PLT_FIRST_ENTRY_WORD5, splt->contents +20 ); bfd_put_32 (output_bfd, PLT_FIRST_ENTRY_WORD6, splt->contents + 24); bfd_put_32 (output_bfd, PLT_FIRST_ENTRY_WORD7, splt->contents + 28 ); /* Fixup relative address to start of GOT */ bfd_put_32 (output_bfd, (sgot->output_section->vma + sgot->output_offset - splt->output_section->vma - 6)/2, splt->contents + 8); } elf_section_data (splt->output_section)->this_hdr.sh_entsize = PLT_ENTRY_SIZE; } /* Set the first entry in the global offset table to the address of the dynamic section. */ if (sgot->_raw_size > 0) { if (sdyn == NULL) bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents); else bfd_put_64 (output_bfd, sdyn->output_section->vma + sdyn->output_offset, sgot->contents); /* One entry for shared object struct ptr. */ bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents + 8); /* One entry for _dl_runtime_resolve. */ bfd_put_64 (output_bfd, (bfd_vma) 0, sgot->contents + 12); } elf_section_data (sgot->output_section)->this_hdr.sh_entsize = 8; return true; } static boolean elf_s390_object_p (abfd) bfd *abfd; { return bfd_default_set_arch_mach (abfd, bfd_arch_s390, bfd_mach_s390_esame); } /* * Why was the hash table entry size definition changed from * ARCH_SIZE/8 to 4? This breaks the 64 bit dynamic linker and * this is the only reason for the s390_elf64_size_info structure. */ const struct elf_size_info s390_elf64_size_info = { sizeof (Elf64_External_Ehdr), sizeof (Elf64_External_Phdr), sizeof (Elf64_External_Shdr), sizeof (Elf64_External_Rel), sizeof (Elf64_External_Rela), sizeof (Elf64_External_Sym), sizeof (Elf64_External_Dyn), sizeof (Elf_External_Note), 8, /* hash-table entry size */ 1, /* internal relocations per external relocations */ 64, /* arch_size */ 8, /* file_align */ ELFCLASS64, EV_CURRENT, bfd_elf64_write_out_phdrs, bfd_elf64_write_shdrs_and_ehdr, bfd_elf64_write_relocs, bfd_elf64_swap_symbol_out, bfd_elf64_slurp_reloc_table, bfd_elf64_slurp_symbol_table, bfd_elf64_swap_dyn_in, bfd_elf64_swap_dyn_out, NULL, NULL, NULL, NULL }; #define TARGET_BIG_SYM bfd_elf64_s390_vec #define TARGET_BIG_NAME "elf64-s390" #define ELF_ARCH bfd_arch_s390 #define ELF_MACHINE_CODE EM_S390 #define ELF_MACHINE_ALT1 EM_S390_OLD #define ELF_MAXPAGESIZE 0x1000 #define elf_backend_size_info s390_elf64_size_info #define elf_backend_can_gc_sections 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 24 #define elf_backend_plt_header_size PLT_ENTRY_SIZE #define elf_info_to_howto elf_s390_info_to_howto #define bfd_elf64_bfd_final_link _bfd_elf64_gc_common_final_link #define bfd_elf64_bfd_is_local_label_name elf_s390_is_local_label_name #define bfd_elf64_bfd_link_hash_table_create elf_s390_link_hash_table_create #define bfd_elf64_bfd_reloc_type_lookup elf_s390_reloc_type_lookup #define elf_backend_adjust_dynamic_symbol elf_s390_adjust_dynamic_symbol #define elf_backend_check_relocs elf_s390_check_relocs #define elf_backend_create_dynamic_sections _bfd_elf_create_dynamic_sections #define elf_backend_finish_dynamic_sections elf_s390_finish_dynamic_sections #define elf_backend_finish_dynamic_symbol elf_s390_finish_dynamic_symbol #define elf_backend_gc_mark_hook elf_s390_gc_mark_hook #define elf_backend_gc_sweep_hook elf_s390_gc_sweep_hook #define elf_backend_relocate_section elf_s390_relocate_section #define elf_backend_size_dynamic_sections elf_s390_size_dynamic_sections #define elf_backend_object_p elf_s390_object_p #include "elf64-target.h"
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