X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=bfd%2Felf32-i386.c;h=d46ece7e7a7c24738f0080cc571833564f8574e5;hb=1a72702bb30ec3f94627cfcae684823b413f20b9;hp=ae3187dc3f7e546b371bbf34159ed444fb7d9e2d;hpb=ead3d5427a2df5e33316d4ad045510c1d2078c2a;p=deliverable%2Fbinutils-gdb.git diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index ae3187dc3f..d46ece7e7a 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -1,5 +1,5 @@ /* Intel 80386/80486-specific support for 32-bit ELF - Copyright (C) 1993-2015 Free Software Foundation, Inc. + Copyright (C) 1993-2016 Free Software Foundation, Inc. This file is part of BFD, the Binary File Descriptor library. @@ -737,6 +737,20 @@ static const struct elf_i386_backend_data elf_i386_arch_bed = #define elf_backend_arch_data &elf_i386_arch_bed +/* Is a undefined weak symbol which is resolved to 0. Reference to an + undefined weak symbol is resolved to 0 when building executable if + it isn't dynamic and + 1. Has non-GOT/non-PLT relocations in text section. Or + 2. Has no GOT/PLT relocation. + */ +#define UNDEFINED_WEAK_RESOLVED_TO_ZERO(INFO, GOT_RELOC, EH) \ + ((EH)->elf.root.type == bfd_link_hash_undefweak \ + && bfd_link_executable (INFO) \ + && (elf_i386_hash_table (INFO)->interp == NULL \ + || !(GOT_RELOC) \ + || (EH)->has_non_got_reloc \ + || !(INFO)->dynamic_undefined_weak)) + /* i386 ELF linker hash entry. */ struct elf_i386_link_hash_entry @@ -767,6 +781,12 @@ struct elf_i386_link_hash_entry /* Symbol is referenced by R_386_GOTOFF relocation. */ unsigned int gotoff_ref : 1; + /* Symbol has GOT or PLT relocations. */ + unsigned int has_got_reloc : 1; + + /* Symbol has non-GOT/non-PLT relocations in text sections. */ + unsigned int has_non_got_reloc : 1; + /* Reference count of C/C++ function pointer relocations in read-write section which can be resolved at run-time. */ bfd_signed_vma func_pointer_refcount; @@ -821,6 +841,7 @@ struct elf_i386_link_hash_table struct elf_link_hash_table elf; /* Short-cuts to get to dynamic linker sections. */ + asection *interp; asection *sdynbss; asection *srelbss; asection *plt_eh_frame; @@ -857,6 +878,10 @@ struct elf_i386_link_hash_table /* The index of the next unused R_386_IRELATIVE slot in .rel.plt. */ bfd_vma next_irelative_index; + + /* TRUE if there are dynamic relocs against IFUNC symbols that apply + to read-only sections. */ + bfd_boolean readonly_dynrelocs_against_ifunc; }; /* Get the i386 ELF linker hash table from a link_info structure. */ @@ -895,6 +920,8 @@ elf_i386_link_hash_newfunc (struct bfd_hash_entry *entry, eh->dyn_relocs = NULL; eh->tls_type = GOT_UNKNOWN; eh->gotoff_ref = 0; + eh->has_got_reloc = 0; + eh->has_non_got_reloc = 0; eh->func_pointer_refcount = 0; eh->plt_got.offset = (bfd_vma) -1; eh->tlsdesc_got = (bfd_vma) -1; @@ -1039,6 +1066,17 @@ elf_i386_create_dynamic_sections (bfd *dynobj, struct bfd_link_info *info) if (htab == NULL) return FALSE; + /* Set the contents of the .interp section to the interpreter. */ + if (bfd_link_executable (info) && !info->nointerp) + { + asection *s = bfd_get_linker_section (dynobj, ".interp"); + if (s == NULL) + abort (); + s->size = sizeof ELF_DYNAMIC_INTERPRETER; + s->contents = (unsigned char *) ELF_DYNAMIC_INTERPRETER; + htab->interp = s; + } + htab->sdynbss = bfd_get_linker_section (dynobj, ".dynbss"); if (!htab->sdynbss) abort (); @@ -1138,6 +1176,9 @@ elf_i386_copy_indirect_symbol (struct bfd_link_info *info, generate a R_386_COPY reloc. */ edir->gotoff_ref |= eind->gotoff_ref; + edir->has_got_reloc |= eind->has_got_reloc; + edir->has_non_got_reloc |= eind->has_non_got_reloc; + if (ELIMINATE_COPY_RELOCS && ind->root.type != bfd_link_hash_indirect && dir->dynamic_adjusted) @@ -1167,7 +1208,7 @@ elf_i386_copy_indirect_symbol (struct bfd_link_info *info, from R_TYPE. */ static bfd_boolean -elf_i386_check_tls_transition (bfd *abfd, asection *sec, +elf_i386_check_tls_transition (asection *sec, bfd_byte *contents, Elf_Internal_Shdr *symtab_hdr, struct elf_link_hash_entry **sym_hashes, @@ -1180,22 +1221,6 @@ elf_i386_check_tls_transition (bfd *abfd, asection *sec, 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) { @@ -1356,7 +1381,8 @@ elf_i386_tls_transition (struct bfd_link_info *info, bfd *abfd, const Elf_Internal_Rela *rel, const Elf_Internal_Rela *relend, struct elf_link_hash_entry *h, - unsigned long r_symndx) + unsigned long r_symndx, + bfd_boolean from_relocate_section) { unsigned int from_type = *r_type; unsigned int to_type = from_type; @@ -1385,10 +1411,9 @@ elf_i386_tls_transition (struct bfd_link_info *info, bfd *abfd, 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) + /* When we are called from elf_i386_relocate_section, there may + be additional transitions based on TLS_TYPE. */ + if (from_relocate_section) { unsigned int new_to_type = to_type; @@ -1432,7 +1457,7 @@ elf_i386_tls_transition (struct bfd_link_info *info, bfd *abfd, /* Check if the transition can be performed. */ if (check - && ! elf_i386_check_tls_transition (abfd, sec, contents, + && ! elf_i386_check_tls_transition (sec, contents, symtab_hdr, sym_hashes, from_type, rel, relend)) { @@ -1474,9 +1499,248 @@ elf_i386_tls_transition (struct bfd_link_info *info, bfd *abfd, return TRUE; } +/* With the local symbol, foo, we convert + mov foo@GOT[(%reg1)], %reg2 + to + lea foo[@GOTOFF(%reg1)], %reg2 + and convert + call/jmp *foo@GOT[(%reg)] + to + nop call foo/jmp foo nop + When PIC is false, convert + test %reg1, foo@GOT[(%reg2)] + to + test $foo, %reg1 + and convert + binop foo@GOT[(%reg1)], %reg2 + to + binop $foo, %reg2 + where binop is one of adc, add, and, cmp, or, sbb, sub, xor + instructions. */ + +static +bfd_boolean +elf_i386_convert_load_reloc (bfd *abfd, Elf_Internal_Shdr *symtab_hdr, + bfd_byte *contents, + Elf_Internal_Rela *irel, + struct elf_link_hash_entry *h, + bfd_boolean *converted, + struct bfd_link_info *link_info) +{ + struct elf_i386_link_hash_table *htab; + unsigned int opcode; + unsigned int modrm; + bfd_boolean baseless; + Elf_Internal_Sym *isym; + unsigned int addend; + unsigned int nop; + bfd_vma nop_offset; + bfd_boolean is_pic; + bfd_boolean to_reloc_32; + unsigned int r_type; + unsigned int r_symndx; + bfd_vma roff = irel->r_offset; + + if (roff < 2) + return TRUE; + + /* Addend for R_386_GOT32X relocations must be 0. */ + addend = bfd_get_32 (abfd, contents + roff); + if (addend != 0) + return TRUE; + + htab = elf_i386_hash_table (link_info); + is_pic = bfd_link_pic (link_info); + + r_type = ELF32_R_TYPE (irel->r_info); + r_symndx = ELF32_R_SYM (irel->r_info); + + modrm = bfd_get_8 (abfd, contents + roff - 1); + baseless = (modrm & 0xc7) == 0x5; + + if (baseless && is_pic) + { + /* For PIC, disallow R_386_GOT32X without a base register + since we don't know what the GOT base is. */ + const char *name; + + if (h == NULL) + { + isym = bfd_sym_from_r_symndx (&htab->sym_cache, abfd, + r_symndx); + name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL); + } + else + name = h->root.root.string; + + (*_bfd_error_handler) + (_("%B: direct GOT relocation R_386_GOT32X against `%s' without base register can not be used when making a shared object"), + abfd, name); + return FALSE; + } + + opcode = bfd_get_8 (abfd, contents + roff - 2); + + /* Convert to R_386_32 if PIC is false or there is no base + register. */ + to_reloc_32 = !is_pic || baseless; + + /* Try to convert R_386_GOT32X. Get the symbol referred to by the + reloc. */ + if (h == NULL) + { + if (opcode == 0x0ff) + /* Convert "call/jmp *foo@GOT[(%reg)]". */ + goto convert_branch; + else + /* Convert "mov foo@GOT[(%reg1)], %reg2", + "test %reg1, foo@GOT(%reg2)" and + "binop foo@GOT[(%reg1)], %reg2". */ + goto convert_load; + } + + /* Undefined weak symbol is only bound locally in executable + and its reference is resolved as 0. */ + if (UNDEFINED_WEAK_RESOLVED_TO_ZERO (link_info, TRUE, + elf_i386_hash_entry (h))) + { + if (opcode == 0xff) + { + /* No direct branch to 0 for PIC. */ + if (is_pic) + return TRUE; + else + goto convert_branch; + } + else + { + /* We can convert load of address 0 to R_386_32. */ + to_reloc_32 = TRUE; + goto convert_load; + } + } + + if (opcode == 0xff) + { + /* We have "call/jmp *foo@GOT[(%reg)]". */ + if ((h->root.type == bfd_link_hash_defined + || h->root.type == bfd_link_hash_defweak) + && SYMBOL_REFERENCES_LOCAL (link_info, h)) + { + /* The function is locally defined. */ +convert_branch: + /* Convert R_386_GOT32X to R_386_PC32. */ + if (modrm == 0x15 || (modrm & 0xf8) == 0x90) + { + /* Convert to "nop call foo". ADDR_PREFIX_OPCODE + is a nop prefix. */ + modrm = 0xe8; + nop = link_info->call_nop_byte; + if (link_info->call_nop_as_suffix) + { + nop_offset = roff + 3; + irel->r_offset -= 1; + } + else + nop_offset = roff - 2; + } + else + { + /* Convert to "jmp foo nop". */ + modrm = 0xe9; + nop = NOP_OPCODE; + nop_offset = roff + 3; + irel->r_offset -= 1; + } + + bfd_put_8 (abfd, nop, contents + nop_offset); + bfd_put_8 (abfd, modrm, contents + irel->r_offset - 1); + /* When converting to PC-relative relocation, we + need to adjust addend by -4. */ + bfd_put_32 (abfd, -4, contents + irel->r_offset); + irel->r_info = ELF32_R_INFO (r_symndx, R_386_PC32); + + *converted = TRUE; + } + } + else + { + /* We have "mov foo@GOT[(%re1g)], %reg2", + "test %reg1, foo@GOT(%reg2)" and + "binop foo@GOT[(%reg1)], %reg2". + + Avoid optimizing _DYNAMIC since ld.so may use its + link-time address. */ + if (h == htab->elf.hdynamic) + return TRUE; + + /* def_regular is set by an assignment in a linker script in + bfd_elf_record_link_assignment. */ + if ((h->def_regular + || h->root.type == bfd_link_hash_defined + || h->root.type == bfd_link_hash_defweak) + && SYMBOL_REFERENCES_LOCAL (link_info, h)) + { +convert_load: + if (opcode == 0x8b) + { + if (to_reloc_32) + { + /* Convert "mov foo@GOT[(%reg1)], %reg2" to + "mov $foo, %reg2" with R_386_32. */ + r_type = R_386_32; + modrm = 0xc0 | (modrm & 0x38) >> 3; + bfd_put_8 (abfd, modrm, contents + roff - 1); + opcode = 0xc7; + } + else + { + /* Convert "mov foo@GOT(%reg1), %reg2" to + "lea foo@GOTOFF(%reg1), %reg2". */ + r_type = R_386_GOTOFF; + opcode = 0x8d; + } + } + else + { + /* Only R_386_32 is supported. */ + if (!to_reloc_32) + return TRUE; + + if (opcode == 0x85) + { + /* Convert "test %reg1, foo@GOT(%reg2)" to + "test $foo, %reg1". */ + modrm = 0xc0 | (modrm & 0x38) >> 3; + opcode = 0xf7; + } + else + { + /* Convert "binop foo@GOT(%reg1), %reg2" to + "binop $foo, %reg2". */ + modrm = (0xc0 + | (modrm & 0x38) >> 3 + | (opcode & 0x3c)); + opcode = 0x81; + } + bfd_put_8 (abfd, modrm, contents + roff - 1); + r_type = R_386_32; + } + + bfd_put_8 (abfd, opcode, contents + roff - 2); + irel->r_info = ELF32_R_INFO (r_symndx, r_type); + + *converted = TRUE; + } + } + + return TRUE; +} + /* Rename some of the generic section flags to better document how they are used here. */ -#define need_convert_load sec_flg0 +#define need_convert_load sec_flg0 +#define check_relocs_failed sec_flg1 /* Look through the relocs for a section during the first phase, and calculate needed space in the global offset table, procedure linkage @@ -1494,6 +1758,7 @@ elf_i386_check_relocs (bfd *abfd, const Elf_Internal_Rela *rel; const Elf_Internal_Rela *rel_end; asection *sreloc; + bfd_byte *contents; bfd_boolean use_plt_got; if (bfd_link_relocatable (info)) @@ -1503,7 +1768,19 @@ elf_i386_check_relocs (bfd *abfd, htab = elf_i386_hash_table (info); if (htab == NULL) - return FALSE; + { + sec->check_relocs_failed = 1; + return FALSE; + } + + /* Get the section contents. */ + if (elf_section_data (sec)->this_hdr.contents != NULL) + contents = elf_section_data (sec)->this_hdr.contents; + else if (!bfd_malloc_and_get_section (abfd, sec, &contents)) + { + sec->check_relocs_failed = 1; + return FALSE; + } use_plt_got = (!get_elf_i386_backend_data (abfd)->is_vxworks && (get_elf_i386_backend_data (abfd) @@ -1533,7 +1810,7 @@ elf_i386_check_relocs (bfd *abfd, (*_bfd_error_handler) (_("%B: bad symbol index: %d"), abfd, r_symndx); - return FALSE; + goto error_return; } if (r_symndx < symtab_hdr->sh_info) @@ -1542,14 +1819,14 @@ elf_i386_check_relocs (bfd *abfd, isym = bfd_sym_from_r_symndx (&htab->sym_cache, abfd, r_symndx); if (isym == NULL) - return FALSE; + goto error_return; /* 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; + goto error_return; /* Fake a STT_GNU_IFUNC symbol. */ h->type = STT_GNU_IFUNC; @@ -1573,10 +1850,6 @@ elf_i386_check_relocs (bfd *abfd, eh = (struct elf_i386_link_hash_entry *) h; 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: @@ -1591,8 +1864,11 @@ elf_i386_check_relocs (bfd *abfd, case R_386_GOT32X: if (htab->elf.dynobj == NULL) htab->elf.dynobj = abfd; - if (!_bfd_elf_create_ifunc_sections (htab->elf.dynobj, info)) - return FALSE; + /* Create the ifunc sections for static executables. */ + if (h->type == STT_GNU_IFUNC + && !_bfd_elf_create_ifunc_sections (htab->elf.dynobj, + info)) + goto error_return; break; } @@ -1605,11 +1881,11 @@ elf_i386_check_relocs (bfd *abfd, |= elf_gnu_symbol_ifunc; } - if (! elf_i386_tls_transition (info, abfd, sec, NULL, + if (! elf_i386_tls_transition (info, abfd, sec, contents, symtab_hdr, sym_hashes, &r_type, GOT_UNKNOWN, - rel, rel_end, h, r_symndx)) - return FALSE; + rel, rel_end, h, r_symndx, FALSE)) + goto error_return; switch (r_type) { @@ -1630,6 +1906,7 @@ elf_i386_check_relocs (bfd *abfd, if (h == NULL) continue; + eh->has_got_reloc = 1; h->needs_plt = 1; h->plt.refcount += 1; break; @@ -1699,7 +1976,7 @@ elf_i386_check_relocs (bfd *abfd, local_got_refcounts = (bfd_signed_vma *) bfd_zalloc (abfd, size); if (local_got_refcounts == NULL) - return FALSE; + goto error_return; elf_local_got_refcounts (abfd) = local_got_refcounts; elf_i386_local_tlsdesc_gotent (abfd) = (bfd_vma *) (local_got_refcounts + symtab_hdr->sh_info); @@ -1735,7 +2012,7 @@ elf_i386_check_relocs (bfd *abfd, "thread local symbol"), abfd, name); bfd_set_error (bfd_error_bad_value); - return FALSE; + goto error_return; } } @@ -1757,22 +2034,39 @@ elf_i386_check_relocs (bfd *abfd, if (htab->elf.dynobj == NULL) htab->elf.dynobj = abfd; if (!_bfd_elf_create_got_section (htab->elf.dynobj, info)) - return FALSE; + goto error_return; } if (r_type != R_386_TLS_IE) - break; + { + if (eh != NULL) + eh->has_got_reloc = 1; + break; + } /* Fall through */ case R_386_TLS_LE_32: case R_386_TLS_LE: + if (eh != NULL) + eh->has_got_reloc = 1; if (bfd_link_executable (info)) break; info->flags |= DF_STATIC_TLS; - /* Fall through */ + goto do_relocation; case R_386_32: case R_386_PC32: - if (h != NULL && bfd_link_executable (info)) + if (eh != NULL && (sec->flags & SEC_CODE) != 0) + eh->has_non_got_reloc = 1; +do_relocation: + /* STT_GNU_IFUNC symbol must go through PLT even if it is + locally defined and undefined symbol may turn out to be + a STT_GNU_IFUNC symbol later. */ + if (h != NULL + && (bfd_link_executable (info) + || ((h->type == STT_GNU_IFUNC + || h->root.type == bfd_link_hash_undefweak + || h->root.type == bfd_link_hash_undefined) + && SYMBOLIC_BIND (info, h)))) { /* If this reloc is in a read-only section, we might need a copy reloc. We can't check reliably at this @@ -1830,7 +2124,8 @@ do_size: && (sec->flags & SEC_ALLOC) != 0 && (r_type != R_386_PC32 || (h != NULL - && (! SYMBOLIC_BIND (info, h) + && (! (bfd_link_pie (info) + || SYMBOLIC_BIND (info, h)) || h->root.type == bfd_link_hash_defweak || !h->def_regular)))) || (ELIMINATE_COPY_RELOCS @@ -1855,7 +2150,7 @@ do_size: (sec, htab->elf.dynobj, 2, abfd, /*rela?*/ FALSE); if (sreloc == NULL) - return FALSE; + goto error_return; } /* If this is a global symbol, we count the number of @@ -1875,7 +2170,7 @@ do_size: isym = bfd_sym_from_r_symndx (&htab->sym_cache, abfd, r_symndx); if (isym == NULL) - return FALSE; + goto error_return; s = bfd_section_from_elf_index (abfd, isym->st_shndx); if (s == NULL) @@ -1892,7 +2187,7 @@ do_size: p = (struct elf_dyn_relocs *) bfd_alloc (htab->elf.dynobj, amt); if (p == NULL) - return FALSE; + goto error_return; p->next = *head; *head = p; p->sec = sec; @@ -1911,7 +2206,7 @@ do_size: 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; + goto error_return; break; /* This relocation describes which C++ vtable entries are actually @@ -1920,7 +2215,7 @@ do_size: BFD_ASSERT (h != NULL); if (h != NULL && !bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_offset)) - return FALSE; + goto error_return; break; default: @@ -1958,15 +2253,32 @@ do_size: || !bfd_set_section_alignment (htab->elf.dynobj, htab->plt_got, plt_got_align)) - return FALSE; + goto error_return; } - if ((r_type == R_386_GOT32 || r_type == R_386_GOT32X) + if (r_type == R_386_GOT32X && (h == NULL || h->type != STT_GNU_IFUNC)) sec->need_convert_load = 1; } + if (elf_section_data (sec)->this_hdr.contents != contents) + { + if (!info->keep_memory) + free (contents); + else + { + /* Cache the section contents for elf_link_input_bfd. */ + elf_section_data (sec)->this_hdr.contents = contents; + } + } + return TRUE; + +error_return: + if (elf_section_data (sec)->this_hdr.contents != contents) + free (contents); + sec->check_relocs_failed = 1; + return FALSE; } /* Return the section that should be marked against GC for a given @@ -1990,160 +2302,22 @@ elf_i386_gc_mark_hook (asection *sec, return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym); } -/* Update the got entry reference counts for the section being removed. */ +/* Remove undefined weak symbol from the dynamic symbol table if it + is resolved to 0. */ static bfd_boolean -elf_i386_gc_sweep_hook (bfd *abfd, - struct bfd_link_info *info, - asection *sec, - const Elf_Internal_Rela *relocs) +elf_i386_fixup_symbol (struct bfd_link_info *info, + struct elf_link_hash_entry *h) { - 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 (bfd_link_relocatable (info)) - 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++) + if (h->dynindx != -1 + && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, + elf_i386_hash_entry (h)->has_got_reloc, + elf_i386_hash_entry (h))) { - 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: - case R_386_GOT32X: - 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: - case R_386_SIZE32: - if (bfd_link_pic (info) - && (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; - if (r_type == R_386_32 - && (sec->flags & SEC_READONLY) == 0) - { - struct elf_i386_link_hash_entry *eh - = (struct elf_i386_link_hash_entry *) h; - if (eh->func_pointer_refcount > 0) - eh->func_pointer_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; - } + h->dynindx = -1; + _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr, + h->dynstr_index); } - return TRUE; } @@ -2335,6 +2509,7 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) struct elf_i386_link_hash_entry *eh; struct elf_dyn_relocs *p; unsigned plt_entry_size; + bfd_boolean resolved_to_zero; if (h->root.type == bfd_link_hash_indirect) return TRUE; @@ -2348,6 +2523,10 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) plt_entry_size = GET_PLT_ENTRY_SIZE (info->output_bfd); + resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, + eh->has_got_reloc, + eh); + /* Clear the reference count of function pointer relocations if symbol isn't a normal function. */ if (h->type != STT_FUNC) @@ -2376,7 +2555,8 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) if (h->type == STT_GNU_IFUNC && h->def_regular) return _bfd_elf_allocate_ifunc_dyn_relocs (info, h, &eh->dyn_relocs, - plt_entry_size, + &htab->readonly_dynrelocs_against_ifunc, + plt_entry_size, plt_entry_size, 4); /* Don't create the PLT entry if there are only function pointer relocations which can be resolved at run-time. */ @@ -2405,7 +2585,8 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) /* 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) + && !h->forced_local + && !resolved_to_zero) { if (! bfd_elf_link_record_dynamic_symbol (info, h)) return FALSE; @@ -2462,9 +2643,15 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) 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++; + /* There should be no PLT relocation against resolved + undefined weak symbol in executable. */ + if (!resolved_to_zero) + { + /* 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 @@ -2490,12 +2677,14 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) } else { + eh->plt_got.offset = (bfd_vma) -1; h->plt.offset = (bfd_vma) -1; h->needs_plt = 0; } } else { + eh->plt_got.offset = (bfd_vma) -1; h->plt.offset = (bfd_vma) -1; h->needs_plt = 0; } @@ -2518,7 +2707,8 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) /* 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) + && !h->forced_local + && !resolved_to_zero) { if (! bfd_elf_link_record_dynamic_symbol (info, h)) return FALSE; @@ -2546,7 +2736,8 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) 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. */ + global. No dynamic relocation against resolved undefined weak + symbol in executable. */ 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) @@ -2555,7 +2746,8 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) 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 + && ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT + && !resolved_to_zero) || h->root.type != bfd_link_hash_undefweak) && (bfd_link_pic (info) || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h))) @@ -2611,15 +2803,43 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) } /* Also discard relocs on undefined weak syms with non-default - visibility. */ + visibility or in PIE. */ if (eh->dyn_relocs != NULL && h->root.type == bfd_link_hash_undefweak) { - if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT) - eh->dyn_relocs = NULL; + /* Undefined weak symbol is never bound locally in shared + library. */ + if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT + || resolved_to_zero) + { + if (h->non_got_ref) + { + /* Keep dynamic non-GOT/non-PLT relocation so that we + can branch to 0 without PLT. */ + struct elf_dyn_relocs **pp; + + for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) + if (p->pc_count == 0) + *pp = p->next; + else + { + /* Remove non-R_386_PC32 relocation. */ + p->count = p->pc_count; + pp = &p->next; + } - /* Make sure undefined weak symbols are output as a dynamic - symbol in PIEs. */ + if (eh->dyn_relocs != NULL) + { + /* Make sure undefined weak symbols are output + as dynamic symbols in PIEs for dynamic non-GOT + non-PLT reloations. */ + if (! bfd_elf_link_record_dynamic_symbol (info, h)) + return FALSE; + } + } + else + eh->dyn_relocs = NULL; + } else if (h->dynindx == -1 && !h->forced_local) { @@ -2635,7 +2855,10 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) dynamic. Keep dynamic relocations for run-time function pointer initialization. */ - if ((!h->non_got_ref || eh->func_pointer_refcount > 0) + if ((!h->non_got_ref + || eh->func_pointer_refcount > 0 + || (h->root.type == bfd_link_hash_undefweak + && !resolved_to_zero)) && ((h->def_dynamic && !h->def_regular) || (htab->elf.dynamic_sections_created @@ -2645,7 +2868,8 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) /* 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) + && !h->forced_local + && !resolved_to_zero) { if (! bfd_elf_link_record_dynamic_symbol (info, h)) return FALSE; @@ -2732,36 +2956,18 @@ elf_i386_readonly_dynrelocs (struct elf_link_hash_entry *h, void *inf) return TRUE; } -/* With the local symbol, foo, we convert - mov foo@GOT[(%reg1)], %reg2 - to - lea foo[@GOTOFF(%reg1)], %reg2 - and convert - call/jmp *foo@GOT[(%reg)] - to - nop call foo/jmp foo nop - When PIC is false, convert - test %reg1, foo@GOT[(%reg2)] - to - test $foo, %reg1 - and convert - binop foo@GOT[(%reg1)], %reg2 - to - binop $foo, %reg2 - where binop is one of adc, add, and, cmp, or, sbb, sub, xor - instructions. */ +/* Convert load via the GOT slot to load immediate. */ static bfd_boolean elf_i386_convert_load (bfd *abfd, asection *sec, struct bfd_link_info *link_info) { + struct elf_i386_link_hash_table *htab; Elf_Internal_Shdr *symtab_hdr; Elf_Internal_Rela *internal_relocs; Elf_Internal_Rela *irel, *irelend; bfd_byte *contents; - struct elf_i386_link_hash_table *htab; - bfd_boolean changed_contents; - bfd_boolean changed_relocs; + bfd_boolean changed; bfd_signed_vma *local_got_refcounts; /* Don't even try to convert non-ELF outputs. */ @@ -2783,9 +2989,8 @@ elf_i386_convert_load (bfd *abfd, asection *sec, if (internal_relocs == NULL) return FALSE; + changed = FALSE; htab = elf_i386_hash_table (link_info); - changed_contents = FALSE; - changed_relocs = FALSE; local_got_refcounts = elf_local_got_refcounts (abfd); /* Get the section contents. */ @@ -2801,254 +3006,50 @@ elf_i386_convert_load (bfd *abfd, asection *sec, for (irel = internal_relocs; irel < irelend; irel++) { unsigned int r_type = ELF32_R_TYPE (irel->r_info); - unsigned int r_symndx = ELF32_R_SYM (irel->r_info); - unsigned int indx; + unsigned int r_symndx; struct elf_link_hash_entry *h; - unsigned int opcode; - unsigned int modrm; - bfd_vma roff; - bfd_boolean baseless; - Elf_Internal_Sym *isym; - unsigned int addend; - unsigned int nop; - bfd_vma nop_offset; - - if (r_type != R_386_GOT32 && r_type != R_386_GOT32X) - continue; + bfd_boolean converted; - roff = irel->r_offset; - if (roff < 2) + /* Don't convert R_386_GOT32 since we can't tell if it is applied + to "mov $foo@GOT, %reg" which isn't a load via GOT. */ + if (r_type != R_386_GOT32X) continue; - modrm = bfd_get_8 (abfd, contents + roff - 1); - baseless = (modrm & 0xc7) == 0x5; - - if (r_type == R_386_GOT32X - && baseless - && bfd_link_pic (link_info)) - { - /* For PIC, disallow R_386_GOT32X without a base register - since we don't know what the GOT base is. Allow - R_386_GOT32 for existing object files. */ - const char *name; - - if (r_symndx < symtab_hdr->sh_info) - { - isym = bfd_sym_from_r_symndx (&htab->sym_cache, abfd, - r_symndx); - name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL); - } - else - { - indx = r_symndx - symtab_hdr->sh_info; - h = elf_sym_hashes (abfd)[indx]; - BFD_ASSERT (h != NULL); - name = h->root.root.string; - } - - (*_bfd_error_handler) - (_("%B: direct GOT relocation R_386_GOT32X against `%s' without base register can not be used when making a shared object"), - abfd, name); - goto error_return; - } - - opcode = bfd_get_8 (abfd, contents + roff - 2); - - /* It is OK to convert mov to lea. */ - if (opcode != 0x8b) - { - /* Only convert R_386_GOT32X relocation for call, jmp or - one of adc, add, and, cmp, or, sbb, sub, test, xor - instructions. */ - if (r_type != R_386_GOT32X) - continue; - - /* It is OK to convert indirect branch to direct branch. It - is OK to convert adc, add, and, cmp, or, sbb, sub, test, - xor only when PIC is false. */ - if (opcode != 0xff && bfd_link_pic (link_info)) - continue; - } - - /* Try to convert R_386_GOT32 and R_386_GOT32X. Get the symbol - referred to by the reloc. */ + r_symndx = ELF32_R_SYM (irel->r_info); if (r_symndx < symtab_hdr->sh_info) + h = elf_i386_get_local_sym_hash (htab, sec->owner, + (const Elf_Internal_Rela *) irel, + FALSE); + else { - isym = bfd_sym_from_r_symndx (&htab->sym_cache, - abfd, r_symndx); - - /* STT_GNU_IFUNC must keep GOT32 relocations. */ - if (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) - continue; - - h = NULL; - if (opcode == 0x0ff) - /* Convert "call/jmp *foo@GOT[(%reg)]". */ - goto convert_branch; - else - /* Convert "mov foo@GOT[(%reg1)], %reg2", - "test %reg1, foo@GOT(%reg2)" and - "binop foo@GOT[(%reg1)], %reg2". */ - goto convert_load; + h = elf_sym_hashes (abfd)[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; } - indx = r_symndx - symtab_hdr->sh_info; - h = elf_sym_hashes (abfd)[indx]; - BFD_ASSERT (h != NULL); - - 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; - /* STT_GNU_IFUNC must keep GOT32 relocations. */ - if (h->type == STT_GNU_IFUNC) + if (h != NULL && h->type == STT_GNU_IFUNC) continue; - if (opcode == 0xff) + converted = FALSE; + if (!elf_i386_convert_load_reloc (abfd, symtab_hdr, contents, + irel, h, &converted, link_info)) + goto error_return; + + if (converted) { - /* We have "call/jmp *foo@GOT[(%reg)]". */ - if ((h->root.type == bfd_link_hash_defined - || h->root.type == bfd_link_hash_defweak) - && SYMBOL_REFERENCES_LOCAL (link_info, h)) + changed = converted; + if (h) { - /* The function is locally defined. */ -convert_branch: - addend = bfd_get_32 (abfd, contents + roff); - /* Addend for R_386_GOT32X relocation must be 0. */ - if (addend != 0) - continue; - - /* Convert R_386_GOT32X to R_386_PC32. */ - if (modrm == 0x15 || (modrm & 0xf8) == 0x90) - { - /* Convert to "nop call foo". ADDR_PREFIX_OPCODE - is a nop prefix. */ - modrm = 0xe8; - nop = link_info->call_nop_byte; - if (link_info->call_nop_as_suffix) - { - nop_offset = roff + 3; - irel->r_offset -= 1; - } - else - nop_offset = roff - 2; - } - else - { - /* Convert to "jmp foo nop". */ - modrm = 0xe9; - nop = NOP_OPCODE; - nop_offset = roff + 3; - irel->r_offset -= 1; - } - - bfd_put_8 (abfd, nop, contents + nop_offset); - bfd_put_8 (abfd, modrm, contents + irel->r_offset - 1); - /* When converting to PC-relative relocation, we - need to adjust addend by -4. */ - bfd_put_32 (abfd, -4, contents + irel->r_offset); - irel->r_info = ELF32_R_INFO (r_symndx, R_386_PC32); - - if (h) - { - if (h->got.refcount > 0) - h->got.refcount -= 1; - } - else - { - if (local_got_refcounts != NULL - && local_got_refcounts[r_symndx] > 0) - local_got_refcounts[r_symndx] -= 1; - } - - changed_contents = TRUE; - changed_relocs = TRUE; + if (h->got.refcount > 0) + h->got.refcount -= 1; } - } - else - { - /* We have "mov foo@GOT[(%re1g)], %reg2", - "test %reg1, foo@GOT(%reg2)" and - "binop foo@GOT[(%reg1)], %reg2". - - Avoid optimizing _DYNAMIC since ld.so may use its - link-time address. */ - if (h == htab->elf.hdynamic) - continue; - - /* def_regular is set by an assignment in a linker script in - bfd_elf_record_link_assignment. */ - if ((h->def_regular - || h->root.type == bfd_link_hash_defined - || h->root.type == bfd_link_hash_defweak) - && SYMBOL_REFERENCES_LOCAL (link_info, h)) + else { -convert_load: - if (opcode == 0x8b) - { - /* Convert "mov foo@GOT(%reg1), %reg2" to - "lea foo@GOTOFF(%reg1), %reg2". */ - if (r_type == R_386_GOT32X - && (baseless || !bfd_link_pic (link_info))) - { - r_type = R_386_32; - /* For R_386_32, convert - "lea foo@GOTOFF(%reg1), %reg2" to - "lea foo@GOT, %reg2". */ - if (!baseless) - { - modrm = 0x5 | (modrm & 0x38); - bfd_put_8 (abfd, modrm, contents + roff - 1); - } - } - else - r_type = R_386_GOTOFF; - opcode = 0x8d; - } - else - { - /* Addend for R_386_GOT32X relocation must be 0. */ - addend = bfd_get_32 (abfd, contents + roff); - if (addend != 0) - continue; - - if (opcode == 0x85) - { - /* Convert "test %reg1, foo@GOT(%reg2)" to - "test $foo, %reg1". */ - modrm = 0xc0 | (modrm & 0x38) >> 3; - opcode = 0xf7; - } - else - { - /* Convert "binop foo@GOT(%reg1), %reg2" to - "binop $foo, %reg2". */ - modrm = (0xc0 - | (modrm & 0x38) >> 3 - | (opcode & 0x3c)); - opcode = 0x81; - } - bfd_put_8 (abfd, modrm, contents + roff - 1); - r_type = R_386_32; - } - - bfd_put_8 (abfd, opcode, contents + roff - 2); - irel->r_info = ELF32_R_INFO (r_symndx, r_type); - - if (h) - { - if (h->got.refcount > 0) - h->got.refcount -= 1; - } - else - { - if (local_got_refcounts != NULL - && local_got_refcounts[r_symndx] > 0) - local_got_refcounts[r_symndx] -= 1; - } - - changed_contents = TRUE; - changed_relocs = TRUE; + if (local_got_refcounts != NULL + && local_got_refcounts[r_symndx] > 0) + local_got_refcounts[r_symndx] -= 1; } } } @@ -3056,7 +3057,7 @@ convert_load: if (contents != NULL && elf_section_data (sec)->this_hdr.contents != contents) { - if (!changed_contents && !link_info->keep_memory) + if (!changed && !link_info->keep_memory) free (contents); else { @@ -3067,7 +3068,7 @@ convert_load: if (elf_section_data (sec)->relocs != internal_relocs) { - if (!changed_relocs) + if (!changed) free (internal_relocs); else elf_section_data (sec)->relocs = internal_relocs; @@ -3103,19 +3104,6 @@ elf_i386_size_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info) if (dynobj == NULL) abort (); - if (htab->elf.dynamic_sections_created) - { - /* Set the contents of the .interp section to the interpreter. */ - if (bfd_link_executable (info) && !info->nointerp) - { - s = bfd_get_linker_section (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) @@ -3424,8 +3412,7 @@ elf_i386_size_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info) if ((info->flags & DF_TEXTREL) != 0) { - if ((elf_tdata (output_bfd)->has_gnu_symbols - & elf_gnu_symbol_ifunc) == elf_gnu_symbol_ifunc) + if (htab->readonly_dynrelocs_against_ifunc) { info->callbacks->einfo (_("%P%X: read-only segment has dynamic IFUNC relocations; recompile with -fPIC\n")); @@ -3606,6 +3593,10 @@ elf_i386_relocate_section (bfd *output_bfd, BFD_ASSERT (is_i386_elf (input_bfd)); + /* Skip if check_relocs failed. */ + if (input_section->check_relocs_failed) + return FALSE; + htab = elf_i386_hash_table (info); if (htab == NULL) return FALSE; @@ -3643,6 +3634,7 @@ elf_i386_relocate_section (bfd *output_bfd, int tls_type; bfd_vma st_size; asection *resolved_plt; + bfd_boolean resolved_to_zero; r_type = ELF32_R_TYPE (rel->r_info); if (r_type == R_386_GNU_VTINHERIT @@ -3984,6 +3976,11 @@ elf_i386_relocate_section (bfd *output_bfd, } eh = (struct elf_i386_link_hash_entry *) h; + resolved_to_zero = (eh != NULL + && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, + eh->has_got_reloc, + eh)); + switch (r_type) { case R_386_GOT32X: @@ -3998,8 +3995,11 @@ elf_i386_relocate_section (bfd *output_bfd, branch to direct branch. It is OK to convert adc, add, and, cmp, or, sbb, sub, test, xor only when PIC is false. */ - unsigned int opcode; - opcode = bfd_get_8 (abfd, contents + rel->r_offset - 2); + unsigned int opcode, addend; + addend = bfd_get_32 (input_bfd, contents + rel->r_offset); + if (addend != 0) + goto r_386_got32; + opcode = bfd_get_8 (input_bfd, contents + rel->r_offset - 2); if (opcode != 0x8b && opcode != 0xff) goto r_386_got32; } @@ -4018,10 +4018,12 @@ elf_i386_relocate_section (bfd *output_bfd, /* It is relative to .got.plt section. */ if (h->got.offset != (bfd_vma) -1) - /* Use GOT entry. */ + /* Use GOT entry. Mask off the least significant bit in + GOT offset which may be set by R_386_GOT32 processing + below. */ relocation = (htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset - + h->got.offset - offplt); + + (h->got.offset & ~1) - offplt); else /* Use GOTPLT entry. */ relocation = (h->plt.offset / plt_entry_size - 1 + 3) * 4; @@ -4031,7 +4033,7 @@ elf_i386_relocate_section (bfd *output_bfd, /* If not PIC, add the .got.plt section address for baseless addressing. */ unsigned int modrm; - modrm = bfd_get_8 (abfd, contents + rel->r_offset - 1); + modrm = bfd_get_8 (input_bfd, contents + rel->r_offset - 1); if ((modrm & 0xc7) == 0x5) relocation += offplt; } @@ -4244,22 +4246,29 @@ r_386_got32: || is_vxworks_tls) break; - /* Copy dynamic function pointer relocations. */ + /* Copy dynamic function pointer relocations. Don't generate + dynamic relocations against resolved undefined weak symbols + in PIE, except for R_386_PC32. */ if ((bfd_link_pic (info) && (h == NULL - || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT - || h->root.type != bfd_link_hash_undefweak) + || ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT + && (!resolved_to_zero + || r_type == R_386_PC32)) + || h->root.type != bfd_link_hash_undefweak)) && ((r_type != R_386_PC32 && r_type != R_386_SIZE32) || !SYMBOL_CALLS_LOCAL (info, h))) || (ELIMINATE_COPY_RELOCS && !bfd_link_pic (info) && h != NULL && h->dynindx != -1 - && (!h->non_got_ref || eh->func_pointer_refcount > 0) - && ((h->def_dynamic - && !h->def_regular) - || h->root.type == bfd_link_hash_undefweak - || h->root.type == bfd_link_hash_undefined))) + && (!h->non_got_ref + || eh->func_pointer_refcount > 0 + || (h->root.type == bfd_link_hash_undefweak + && !resolved_to_zero)) + && ((h->def_dynamic && !h->def_regular) + /* Undefined weak symbol is bound locally when + PIC is false. */ + || h->root.type == bfd_link_hash_undefweak))) { Elf_Internal_Rela outrel; bfd_boolean skip, relocate; @@ -4287,8 +4296,8 @@ r_386_got32: else if (h != NULL && h->dynindx != -1 && (r_type == R_386_PC32 - || !bfd_link_pic (info) - || !SYMBOLIC_BIND (info, h) + || !(bfd_link_executable (info) + || SYMBOLIC_BIND (info, h)) || !h->def_regular)) outrel.r_info = ELF32_R_INFO (h->dynindx, r_type); else @@ -4351,7 +4360,7 @@ r_386_got32: input_section, contents, symtab_hdr, sym_hashes, &r_type, tls_type, rel, - relend, h, r_symndx)) + relend, h, r_symndx, TRUE)) return FALSE; if (r_type == R_386_TLS_LE_32) @@ -4812,7 +4821,7 @@ r_386_got32: input_section, contents, symtab_hdr, sym_hashes, &r_type, GOT_UNKNOWN, rel, - relend, h, r_symndx)) + relend, h, r_symndx, TRUE)) return FALSE; if (r_type != R_386_TLS_LDM) @@ -4952,13 +4961,9 @@ check_relocation_error: } 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; - } + (*info->callbacks->reloc_overflow) + (info, (h ? &h->root : NULL), name, howto->name, + (bfd_vma) 0, input_bfd, input_section, rel->r_offset); else { (*_bfd_error_handler) @@ -5009,6 +5014,7 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd, unsigned plt_entry_size; const struct elf_i386_backend_data *abed; struct elf_i386_link_hash_entry *eh; + bfd_boolean local_undefweak; htab = elf_i386_hash_table (info); if (htab == NULL) @@ -5019,6 +5025,13 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd, eh = (struct elf_i386_link_hash_entry *) h; + /* We keep PLT/GOT entries without dynamic PLT/GOT relocations for + resolved undefined weak symbols in executable so that their + references have value 0 at run-time. */ + local_undefweak = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, + eh->has_got_reloc, + eh); + if (h->plt.offset != (bfd_vma) -1) { bfd_vma plt_index; @@ -5046,6 +5059,7 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd, it up. */ if ((h->dynindx == -1 + && !local_undefweak && !((h->forced_local || bfd_link_executable (info)) && h->def_regular && h->type == STT_GNU_IFUNC)) @@ -5134,54 +5148,61 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd, + 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 - || ((bfd_link_executable (info) - || ELF_ST_VISIBILITY (h->other) != STV_DEFAULT) - && h->def_regular - && h->type == STT_GNU_IFUNC)) + /* Fill in the entry in the global offset table. Leave the entry + as zero for undefined weak symbol in PIE. No PLT relocation + against undefined weak symbol in PIE. */ + if (!local_undefweak) { - /* 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), + (plt->output_section->vma + + plt->output_offset + + h->plt.offset + + abed->plt->plt_lazy_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); + /* 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 + || ((bfd_link_executable (info) + || 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); + } } } else if (eh->plt_got.offset != (bfd_vma) -1) @@ -5227,7 +5248,8 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd, plt->contents + plt_offset + plt_got_offset); } - if (!h->def_regular + if (!local_undefweak + && !h->def_regular && (h->plt.offset != (bfd_vma) -1 || eh->plt_got.offset != (bfd_vma) -1)) { @@ -5244,9 +5266,12 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd, sym->st_value = 0; } + /* Don't generate dynamic GOT relocation against undefined weak + symbol in executable. */ 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_i386_hash_entry(h)->tls_type & GOT_TLS_IE) == 0 + && !local_undefweak) { Elf_Internal_Rela rel; @@ -5346,6 +5371,25 @@ elf_i386_finish_local_dynamic_symbol (void **slot, void *inf) h, NULL); } +/* Finish up undefined weak symbol handling in PIE. Fill its PLT entry + here since undefined weak symbol may not be dynamic and may not be + called for elf_i386_finish_dynamic_symbol. */ + +static bfd_boolean +elf_i386_pie_finish_undefweak_symbol (struct bfd_hash_entry *bh, + void *inf) +{ + struct elf_link_hash_entry *h = (struct elf_link_hash_entry *) bh; + struct bfd_link_info *info = (struct bfd_link_info *) inf; + + if (h->root.type != bfd_link_hash_undefweak + || h->dynindx != -1) + return TRUE; + + 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. */ @@ -5357,19 +5401,23 @@ elf_i386_reloc_type_class (const struct bfd_link_info *info, bfd *abfd = info->output_bfd; const struct elf_backend_data *bed = get_elf_backend_data (abfd); struct elf_link_hash_table *htab = elf_hash_table (info); - unsigned long r_symndx = ELF32_R_SYM (rela->r_info); - Elf_Internal_Sym sym; - - if (htab->dynsym == NULL - || !bed->s->swap_symbol_in (abfd, - (htab->dynsym->contents - + r_symndx * sizeof (Elf32_External_Sym)), - 0, &sym)) - abort (); - /* Check relocation against STT_GNU_IFUNC symbol. */ - if (ELF32_ST_TYPE (sym.st_info) == STT_GNU_IFUNC) - return reloc_class_ifunc; + if (htab->dynsym != NULL + && htab->dynsym->contents != NULL) + { + /* Check relocation against STT_GNU_IFUNC symbol if there are + dynamic symbols. */ + unsigned long r_symndx = ELF32_R_SYM (rela->r_info); + Elf_Internal_Sym sym; + if (!bed->s->swap_symbol_in (abfd, + (htab->dynsym->contents + + r_symndx * sizeof (Elf32_External_Sym)), + 0, &sym)) + abort (); + + if (ELF32_ST_TYPE (sym.st_info) == STT_GNU_IFUNC) + return reloc_class_ifunc; + } switch (ELF32_R_TYPE (rela->r_info)) { @@ -5620,6 +5668,12 @@ elf_i386_finish_dynamic_sections (bfd *output_bfd, elf_i386_finish_local_dynamic_symbol, info); + /* Fill PLT entries for undefined weak symbols in PIE. */ + if (bfd_link_pie (info)) + bfd_hash_traverse (&info->hash->table, + elf_i386_pie_finish_undefweak_symbol, + info); + return TRUE; } @@ -5682,9 +5736,9 @@ bad_return: reloc_index = H_GET_32 (abfd, (plt_contents + plt_offset + bed->plt->plt_reloc_offset)); reloc_index /= sizeof (Elf32_External_Rel); - if (reloc_index >= count) - abort (); - plt_sym_val[reloc_index] = plt->vma + plt_offset; + if (reloc_index < count) + plt_sym_val[reloc_index] = plt->vma + plt_offset; + plt_offset += bed->plt->plt_entry_size; /* PR binutils/18437: Skip extra relocations in the .rel.plt @@ -5728,27 +5782,6 @@ elf_i386_hash_symbol (struct elf_link_hash_entry *h) 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, - Elf_Internal_Sym * sym, - const char ** namep ATTRIBUTE_UNUSED, - flagword * flagsp ATTRIBUTE_UNUSED, - asection ** secp ATTRIBUTE_UNUSED, - bfd_vma * valp ATTRIBUTE_UNUSED) -{ - if (ELF_ST_BIND (sym->st_info) == STB_GNU_UNIQUE - && (abfd->flags & DYNAMIC) == 0 - && bfd_get_flavour (info->output_bfd) == bfd_target_elf_flavour) - elf_tdata (info->output_bfd)->has_gnu_symbols - |= elf_gnu_symbol_unique; - - return TRUE; -} - #define TARGET_LITTLE_SYM i386_elf32_vec #define TARGET_LITTLE_NAME "elf32-i386" #define ELF_ARCH bfd_arch_i386 @@ -5764,6 +5797,7 @@ elf_i386_add_symbol_hook (bfd * abfd, #define elf_backend_got_header_size 12 #define elf_backend_plt_alignment 4 #define elf_backend_extern_protected_data 1 +#define elf_backend_caches_rawsize 1 /* Support RELA for objdump of prelink objects. */ #define elf_info_to_howto elf_i386_info_to_howto_rel @@ -5786,7 +5820,6 @@ elf_i386_add_symbol_hook (bfd * abfd, #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 @@ -5796,7 +5829,7 @@ elf_i386_add_symbol_hook (bfd * abfd, #define elf_backend_omit_section_dynsym \ ((bfd_boolean (*) (bfd *, struct bfd_link_info *, asection *)) bfd_true) #define elf_backend_hash_symbol elf_i386_hash_symbol -#define elf_backend_add_symbol_hook elf_i386_add_symbol_hook +#define elf_backend_fixup_symbol elf_i386_fixup_symbol #include "elf32-target.h" @@ -5854,16 +5887,99 @@ elf_i386_fbsd_post_process_headers (bfd *abfd, struct bfd_link_info *info) /* The 32-bit static TLS arena size is rounded to the nearest 8-byte boundary. */ -#undef elf_backend_static_tls_alignment +#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 +#undef elf_backend_want_plt_sym #define elf_backend_want_plt_sym 1 +#undef elf_backend_strtab_flags +#define elf_backend_strtab_flags SHF_STRINGS + +/* Called to set the sh_flags, sh_link and sh_info fields of OSECTION which + has a type >= SHT_LOOS. Returns TRUE if these fields were initialised + FALSE otherwise. ISECTION is the best guess matching section from the + input bfd IBFD, but it might be NULL. */ + +static bfd_boolean +elf32_i386_copy_solaris_special_section_fields (const bfd *ibfd ATTRIBUTE_UNUSED, + bfd *obfd ATTRIBUTE_UNUSED, + const Elf_Internal_Shdr *isection ATTRIBUTE_UNUSED, + Elf_Internal_Shdr *osection ATTRIBUTE_UNUSED) +{ + /* PR 19938: FIXME: Need to add code for setting the sh_info + and sh_link fields of Solaris specific section types. */ + return FALSE; + + /* Based upon Oracle Solaris 11.3 Linkers and Libraries Guide, Ch. 13, + Object File Format, Table 13-9 ELF sh_link and sh_info Interpretation: + +http://docs.oracle.com/cd/E53394_01/html/E54813/chapter6-94076.html#scrolltoc + + The following values should be set: + +Type Link Info +----------------------------------------------------------------------------- +SHT_SUNW_ancillary The section header index of 0 + [0x6fffffee] the associated string table. + +SHT_SUNW_capinfo The section header index of For a dynamic object, the + [0x6ffffff0] the associated symbol table. section header index of + the associated + SHT_SUNW_capchain table, + otherwise 0. + +SHT_SUNW_symsort The section header index of 0 + [0x6ffffff1] the associated symbol table. + +SHT_SUNW_tlssort The section header index of 0 + [0x6ffffff2] the associated symbol table. + +SHT_SUNW_LDYNSYM The section header index of One greater than the + [0x6ffffff3] the associated string table. symbol table index of the + This index is the same string last local symbol, + table used by the SHT_DYNSYM STB_LOCAL. Since + section. SHT_SUNW_LDYNSYM only + contains local symbols, + sh_info is equivalent to + the number of symbols in + the table. + +SHT_SUNW_cap If symbol capabilities exist, If any capabilities refer + [0x6ffffff5] the section header index of to named strings, the + the associated section header index of + SHT_SUNW_capinfo table, the associated string + otherwise 0. table, otherwise 0. + +SHT_SUNW_move The section header index of 0 + [0x6ffffffa] the associated symbol table. + +SHT_SUNW_COMDAT 0 0 + [0x6ffffffb] + +SHT_SUNW_syminfo The section header index of The section header index + [0x6ffffffc] the associated symbol table. of the associated + .dynamic section. + +SHT_SUNW_verdef The section header index of The number of version + [0x6ffffffd] the associated string table. definitions within the + section. + +SHT_SUNW_verneed The section header index of The number of version + [0x6ffffffe] the associated string table. dependencies within the + section. + +SHT_SUNW_versym The section header index of 0 + [0x6fffffff] the associated symbol table. */ +} + +#undef elf_backend_copy_special_section_fields +#define elf_backend_copy_special_section_fields elf32_i386_copy_solaris_special_section_fields + #include "elf32-target.h" /* Intel MCU support. */ @@ -5880,7 +5996,7 @@ elf32_iamcu_elf_object_p (bfd *abfd) #define TARGET_LITTLE_SYM iamcu_elf32_vec #undef TARGET_LITTLE_NAME #define TARGET_LITTLE_NAME "elf32-iamcu" -#undef ELF_ARCH +#undef ELF_ARCH #define ELF_ARCH bfd_arch_iamcu #undef ELF_MACHINE_CODE @@ -5899,6 +6015,9 @@ elf32_iamcu_elf_object_p (bfd *abfd) #undef elf_backend_want_plt_sym #define elf_backend_want_plt_sym 0 +#undef elf_backend_strtab_flags +#undef elf_backend_copy_special_section_fields + #include "elf32-target.h" /* Restore defaults. */