X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=bfd%2Felf64-x86-64.c;h=170b61a7396d5c382e9fc798ce9a57796b54693d;hb=ed53407eec9eba3b55a3a00fb7eaa7eddbf01363;hp=cbb8cfb348431791a8fed0632832736cb4dd37a9;hpb=9b8b325a1f4cdaf235e7d803849dde6ededec865;p=deliverable%2Fbinutils-gdb.git diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index cbb8cfb348..170b61a739 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -1,5 +1,5 @@ /* X86-64 specific support for ELF - Copyright (C) 2000-2015 Free Software Foundation, Inc. + Copyright (C) 2000-2016 Free Software Foundation, Inc. Contributed by Jan Hubicka . This file is part of BFD, the Binary File Descriptor library. @@ -31,6 +31,7 @@ #include "dwarf2.h" #include "libiberty.h" +#include "opcode/i386.h" #include "elf/x86-64.h" #ifdef CORE_HEADER @@ -176,12 +177,18 @@ static reloc_howto_type x86_64_elf_howto_table[] = HOWTO(R_X86_64_PLT32_BND, 0, 2, 32, TRUE, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_PLT32_BND", FALSE, 0xffffffff, 0xffffffff, TRUE), + HOWTO(R_X86_64_GOTPCRELX, 0, 2, 32, TRUE, 0, complain_overflow_signed, + bfd_elf_generic_reloc, "R_X86_64_GOTPCRELX", FALSE, 0xffffffff, + 0xffffffff, TRUE), + HOWTO(R_X86_64_REX_GOTPCRELX, 0, 2, 32, TRUE, 0, complain_overflow_signed, + bfd_elf_generic_reloc, "R_X86_64_REX_GOTPCRELX", FALSE, 0xffffffff, + 0xffffffff, TRUE), /* We have a gap in the reloc numbers here. R_X86_64_standard counts the number up to this point, and R_X86_64_vt_offset is the value to subtract from a reloc type of R_X86_64_GNU_VT* to form an index into this table. */ -#define R_X86_64_standard (R_X86_64_PLT32_BND + 1) +#define R_X86_64_standard (R_X86_64_REX_GOTPCRELX + 1) #define R_X86_64_vt_offset (R_X86_64_GNU_VTINHERIT - R_X86_64_standard) /* GNU extension to record C++ vtable hierarchy. */ @@ -253,8 +260,10 @@ static const struct elf_reloc_map x86_64_reloc_map[] = { BFD_RELOC_X86_64_TLSDESC_CALL, R_X86_64_TLSDESC_CALL, }, { BFD_RELOC_X86_64_TLSDESC, R_X86_64_TLSDESC, }, { BFD_RELOC_X86_64_IRELATIVE, R_X86_64_IRELATIVE, }, - { BFD_RELOC_X86_64_PC32_BND, R_X86_64_PC32_BND,}, - { BFD_RELOC_X86_64_PLT32_BND, R_X86_64_PLT32_BND,}, + { BFD_RELOC_X86_64_PC32_BND, R_X86_64_PC32_BND, }, + { BFD_RELOC_X86_64_PLT32_BND, R_X86_64_PLT32_BND, }, + { BFD_RELOC_X86_64_GOTPCRELX, R_X86_64_GOTPCRELX, }, + { BFD_RELOC_X86_64_REX_GOTPCRELX, R_X86_64_REX_GOTPCRELX, }, { BFD_RELOC_VTABLE_INHERIT, R_X86_64_GNU_VTINHERIT, }, { BFD_RELOC_VTABLE_ENTRY, R_X86_64_GNU_VTENTRY, }, }; @@ -733,6 +742,20 @@ static const struct elf_x86_64_backend_data elf_x86_64_bnd_arch_bed = #define elf_backend_arch_data &elf_x86_64_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_x86_64_hash_table (INFO)->interp == NULL \ + || !(GOT_RELOC) \ + || (EH)->has_non_got_reloc \ + || !(INFO)->dynamic_undefined_weak)) + /* x86-64 ELF linker hash entry. */ struct elf_x86_64_link_hash_entry @@ -767,6 +790,12 @@ struct elf_x86_64_link_hash_entry /* TRUE if symbol has at least one BND relocation. */ unsigned int has_bnd_reloc : 1; + /* TRUE if symbol has GOT or PLT relocations. */ + unsigned int has_got_reloc : 1; + + /* TRUE if 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; @@ -826,6 +855,7 @@ struct elf_x86_64_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; @@ -870,6 +900,10 @@ struct elf_x86_64_link_hash_table bfd_vma next_jump_slot_index; /* The index of the next R_X86_64_IRELATIVE entry in .rela.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 x86-64 ELF linker hash table from a link_info structure. */ @@ -910,6 +944,8 @@ elf_x86_64_link_hash_newfunc (struct bfd_hash_entry *entry, eh->tls_type = GOT_UNKNOWN; eh->needs_copy = 0; eh->has_bnd_reloc = 0; + eh->has_got_reloc = 0; + eh->has_non_got_reloc = 0; eh->func_pointer_refcount = 0; eh->plt_bnd.offset = (bfd_vma) -1; eh->plt_got.offset = (bfd_vma) -1; @@ -1073,6 +1109,17 @@ elf_x86_64_create_dynamic_sections (bfd *dynobj, 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 = htab->dynamic_interpreter_size; + s->contents = (unsigned char *) htab->dynamic_interpreter; + htab->interp = s; + } + htab->sdynbss = bfd_get_linker_section (dynobj, ".dynbss"); if (!htab->sdynbss) abort (); @@ -1127,6 +1174,12 @@ elf_x86_64_copy_indirect_symbol (struct bfd_link_info *info, if (!edir->has_bnd_reloc) edir->has_bnd_reloc = eind->has_bnd_reloc; + if (!edir->has_got_reloc) + edir->has_got_reloc = eind->has_got_reloc; + + if (!edir->has_non_got_reloc) + edir->has_non_got_reloc = eind->has_non_got_reloc; + if (eind->dyn_relocs != NULL) { if (edir->dyn_relocs != NULL) @@ -1227,22 +1280,6 @@ elf_x86_64_check_tls_transition (bfd *abfd, bfd_vma offset; struct elf_x86_64_link_hash_table *htab; - /* 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; - } - } - htab = elf_x86_64_hash_table (info); offset = rel->r_offset; switch (r_type) @@ -1430,7 +1467,8 @@ elf_x86_64_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; @@ -1456,10 +1494,9 @@ elf_x86_64_tls_transition (struct bfd_link_info *info, bfd *abfd, to_type = R_X86_64_GOTTPOFF; } - /* When we are called from elf_x86_64_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_x86_64_relocate_section, there may + be additional transitions based on TLS_TYPE. */ + if (from_relocate_section) { unsigned int new_to_type = to_type; @@ -1545,7 +1582,457 @@ elf_x86_64_tls_transition (struct bfd_link_info *info, bfd *abfd, /* Rename some of the generic section flags to better document how they are used here. */ -#define need_convert_mov_to_lea sec_flg0 +#define need_convert_load sec_flg0 +#define check_relocs_failed sec_flg1 + +static bfd_boolean +elf_x86_64_need_pic (bfd *input_bfd, asection *sec, + struct elf_link_hash_entry *h, + Elf_Internal_Shdr *symtab_hdr, + Elf_Internal_Sym *isym, + reloc_howto_type *howto) +{ + const char *v = ""; + const char *und = ""; + const char *pic = ""; + + const char *name; + if (h) + { + name = h->root.root.string; + switch (ELF_ST_VISIBILITY (h->other)) + { + case STV_HIDDEN: + v = _("hidden symbol "); + break; + case STV_INTERNAL: + v = _("internal symbol "); + break; + case STV_PROTECTED: + v = _("protected symbol "); + break; + default: + v = _("symbol "); + pic = _("; recompile with -fPIC"); + break; + } + + if (!h->def_regular && !h->def_dynamic) + und = _("undefined "); + } + else + { + name = bfd_elf_sym_name (input_bfd, symtab_hdr, isym, NULL); + pic = _("; recompile with -fPIC"); + } + + (*_bfd_error_handler) (_("%B: relocation %s against %s%s`%s' can " + "not be used when making a shared object%s"), + input_bfd, howto->name, und, v, name, pic); + bfd_set_error (bfd_error_bad_value); + sec->check_relocs_failed = 1; + return FALSE; +} + +/* With the local symbol, foo, we convert + mov foo@GOTPCREL(%rip), %reg + to + lea foo(%rip), %reg + and convert + call/jmp *foo@GOTPCREL(%rip) + to + nop call foo/jmp foo nop + When PIC is false, convert + test %reg, foo@GOTPCREL(%rip) + to + test $foo, %reg + and convert + binop foo@GOTPCREL(%rip), %reg + to + binop $foo, %reg + where binop is one of adc, add, and, cmp, or, sbb, sub, xor + instructions. */ + +static bfd_boolean +elf_x86_64_convert_load_reloc (bfd *abfd, asection *sec, + bfd_byte *contents, + Elf_Internal_Rela *irel, + struct elf_link_hash_entry *h, + bfd_boolean *converted, + struct bfd_link_info *link_info) +{ + struct elf_x86_64_link_hash_table *htab; + bfd_boolean is_pic; + bfd_boolean require_reloc_pc32; + bfd_boolean relocx; + bfd_boolean to_reloc_pc32; + asection *tsec; + char symtype; + bfd_signed_vma raddend; + unsigned int opcode; + unsigned int modrm; + unsigned int r_type = ELF32_R_TYPE (irel->r_info); + unsigned int r_symndx; + bfd_vma toff; + bfd_vma roff = irel->r_offset; + + if (roff < (r_type == R_X86_64_REX_GOTPCRELX ? 3 : 2)) + return TRUE; + + raddend = irel->r_addend; + /* Addend for 32-bit PC-relative relocation must be -4. */ + if (raddend != -4) + return TRUE; + + htab = elf_x86_64_hash_table (link_info); + is_pic = bfd_link_pic (link_info); + + relocx = (r_type == R_X86_64_GOTPCRELX + || r_type == R_X86_64_REX_GOTPCRELX); + + /* TRUE if we can convert only to R_X86_64_PC32. Enable it for + --no-relax. */ + require_reloc_pc32 + = link_info->disable_target_specific_optimizations > 1; + + r_symndx = htab->r_sym (irel->r_info); + + opcode = bfd_get_8 (abfd, contents + roff - 2); + + /* Convert mov to lea since it has been done for a while. */ + if (opcode != 0x8b) + { + /* Only convert R_X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX + for call, jmp or one of adc, add, and, cmp, or, sbb, sub, + test, xor instructions. */ + if (!relocx) + return TRUE; + } + + /* We convert only to R_X86_64_PC32: + 1. Branch. + 2. R_X86_64_GOTPCREL since we can't modify REX byte. + 3. require_reloc_pc32 is true. + 4. PIC. + */ + to_reloc_pc32 = (opcode == 0xff + || !relocx + || require_reloc_pc32 + || is_pic); + + /* Get the symbol referred to by the reloc. */ + if (h == NULL) + { + Elf_Internal_Sym *isym + = bfd_sym_from_r_symndx (&htab->sym_cache, abfd, r_symndx); + + /* Skip relocation against undefined symbols. */ + if (isym->st_shndx == SHN_UNDEF) + return TRUE; + + symtype = ELF_ST_TYPE (isym->st_info); + + if (isym->st_shndx == SHN_ABS) + tsec = bfd_abs_section_ptr; + else if (isym->st_shndx == SHN_COMMON) + tsec = bfd_com_section_ptr; + else if (isym->st_shndx == SHN_X86_64_LCOMMON) + tsec = &_bfd_elf_large_com_section; + else + tsec = bfd_section_from_elf_index (abfd, isym->st_shndx); + + toff = isym->st_value; + } + else + { + /* Undefined weak symbol is only bound locally in executable + and its reference is resolved as 0 without relocation + overflow. We can only perform this optimization for + GOTPCRELX relocations since we need to modify REX byte. + It is OK convert mov with R_X86_64_GOTPCREL to + R_X86_64_PC32. */ + if ((relocx || opcode == 0x8b) + && UNDEFINED_WEAK_RESOLVED_TO_ZERO (link_info, + TRUE, + elf_x86_64_hash_entry (h))) + { + if (opcode == 0xff) + { + /* Skip for branch instructions since R_X86_64_PC32 + may overflow. */ + if (require_reloc_pc32) + return TRUE; + } + else if (relocx) + { + /* For non-branch instructions, we can convert to + R_X86_64_32/R_X86_64_32S since we know if there + is a REX byte. */ + to_reloc_pc32 = FALSE; + } + + /* Since we don't know the current PC when PIC is true, + we can't convert to R_X86_64_PC32. */ + if (to_reloc_pc32 && is_pic) + return TRUE; + + goto convert; + } + /* Avoid optimizing GOTPCREL relocations againt _DYNAMIC since + ld.so may use its link-time address. */ + else if ((h->def_regular + || h->root.type == bfd_link_hash_defined + || h->root.type == bfd_link_hash_defweak) + && h != htab->elf.hdynamic + && SYMBOL_REFERENCES_LOCAL (link_info, h)) + { + /* bfd_link_hash_new or bfd_link_hash_undefined 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_new + || h->root.type == bfd_link_hash_undefined)) + { + /* Skip since R_X86_64_32/R_X86_64_32S may overflow. */ + if (require_reloc_pc32) + return TRUE; + goto convert; + } + tsec = h->root.u.def.section; + toff = h->root.u.def.value; + symtype = h->type; + } + else + return TRUE; + } + + /* Don't convert GOTPCREL relocation against large section. */ + if (elf_section_data (tsec) != NULL + && (elf_section_flags (tsec) & SHF_X86_64_LARGE) != 0) + return TRUE; + + /* We can only estimate relocation overflow for R_X86_64_PC32. */ + if (!to_reloc_pc32) + goto convert; + + if (tsec->sec_info_type == SEC_INFO_TYPE_MERGE) + { + /* At this stage in linking, no SEC_MERGE symbol has been + adjusted, so all references to such symbols need to be + passed through _bfd_merged_section_offset. (Later, in + relocate_section, all SEC_MERGE symbols *except* for + section symbols have been adjusted.) + + gas may reduce relocations against symbols in SEC_MERGE + sections to a relocation against the section symbol when + the original addend was zero. When the reloc is against + a section symbol we should include the addend in the + offset passed to _bfd_merged_section_offset, since the + location of interest is the original symbol. On the + other hand, an access to "sym+addend" where "sym" is not + a section symbol should not include the addend; Such an + access is presumed to be an offset from "sym"; The + location of interest is just "sym". */ + if (symtype == STT_SECTION) + toff += raddend; + + toff = _bfd_merged_section_offset (abfd, &tsec, + elf_section_data (tsec)->sec_info, + toff); + + if (symtype != STT_SECTION) + toff += raddend; + } + else + toff += raddend; + + /* Don't convert if R_X86_64_PC32 relocation overflows. */ + if (tsec->output_section == sec->output_section) + { + if ((toff - roff + 0x80000000) > 0xffffffff) + return TRUE; + } + else + { + bfd_signed_vma distance; + + /* At this point, we don't know the load addresses of TSEC + section nor SEC section. We estimate the distrance between + SEC and TSEC. We store the estimated distances in the + compressed_size field of the output section, which is only + used to decompress the compressed input section. */ + if (sec->output_section->compressed_size == 0) + { + asection *asect; + bfd_size_type size = 0; + for (asect = link_info->output_bfd->sections; + asect != NULL; + asect = asect->next) + /* Skip debug sections since compressed_size is used to + compress debug sections. */ + if ((asect->flags & SEC_DEBUGGING) == 0) + { + asection *i; + for (i = asect->map_head.s; + i != NULL; + i = i->map_head.s) + { + size = align_power (size, i->alignment_power); + size += i->size; + } + asect->compressed_size = size; + } + } + + /* Don't convert GOTPCREL relocations if TSEC isn't placed + after SEC. */ + distance = (tsec->output_section->compressed_size + - sec->output_section->compressed_size); + if (distance < 0) + return TRUE; + + /* Take PT_GNU_RELRO segment into account by adding + maxpagesize. */ + if ((toff + distance + get_elf_backend_data (abfd)->maxpagesize + - roff + 0x80000000) > 0xffffffff) + return TRUE; + } + +convert: + if (opcode == 0xff) + { + /* We have "call/jmp *foo@GOTPCREL(%rip)". */ + unsigned int nop; + unsigned int disp; + bfd_vma nop_offset; + + /* Convert R_X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX to + R_X86_64_PC32. */ + modrm = bfd_get_8 (abfd, contents + roff - 1); + if (modrm == 0x25) + { + /* Convert to "jmp foo nop". */ + modrm = 0xe9; + nop = NOP_OPCODE; + nop_offset = irel->r_offset + 3; + disp = bfd_get_32 (abfd, contents + irel->r_offset); + irel->r_offset -= 1; + bfd_put_32 (abfd, disp, contents + irel->r_offset); + } + else + { + /* 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 = irel->r_offset + 3; + disp = bfd_get_32 (abfd, contents + irel->r_offset); + irel->r_offset -= 1; + bfd_put_32 (abfd, disp, contents + irel->r_offset); + } + else + nop_offset = irel->r_offset - 2; + } + bfd_put_8 (abfd, nop, contents + nop_offset); + bfd_put_8 (abfd, modrm, contents + irel->r_offset - 1); + r_type = R_X86_64_PC32; + } + else + { + unsigned int rex; + unsigned int rex_mask = REX_R; + + if (r_type == R_X86_64_REX_GOTPCRELX) + rex = bfd_get_8 (abfd, contents + roff - 3); + else + rex = 0; + + if (opcode == 0x8b) + { + if (to_reloc_pc32) + { + /* Convert "mov foo@GOTPCREL(%rip), %reg" to + "lea foo(%rip), %reg". */ + opcode = 0x8d; + r_type = R_X86_64_PC32; + } + else + { + /* Convert "mov foo@GOTPCREL(%rip), %reg" to + "mov $foo, %reg". */ + opcode = 0xc7; + modrm = bfd_get_8 (abfd, contents + roff - 1); + modrm = 0xc0 | (modrm & 0x38) >> 3; + if ((rex & REX_W) != 0 + && ABI_64_P (link_info->output_bfd)) + { + /* Keep the REX_W bit in REX byte for LP64. */ + r_type = R_X86_64_32S; + goto rewrite_modrm_rex; + } + else + { + /* If the REX_W bit in REX byte isn't needed, + use R_X86_64_32 and clear the W bit to avoid + sign-extend imm32 to imm64. */ + r_type = R_X86_64_32; + /* Clear the W bit in REX byte. */ + rex_mask |= REX_W; + goto rewrite_modrm_rex; + } + } + } + else + { + /* R_X86_64_PC32 isn't supported. */ + if (to_reloc_pc32) + return TRUE; + + modrm = bfd_get_8 (abfd, contents + roff - 1); + if (opcode == 0x85) + { + /* Convert "test %reg, foo@GOTPCREL(%rip)" to + "test $foo, %reg". */ + modrm = 0xc0 | (modrm & 0x38) >> 3; + opcode = 0xf7; + } + else + { + /* Convert "binop foo@GOTPCREL(%rip), %reg" to + "binop $foo, %reg". */ + modrm = 0xc0 | (modrm & 0x38) >> 3 | (opcode & 0x3c); + opcode = 0x81; + } + + /* Use R_X86_64_32 with 32-bit operand to avoid relocation + overflow when sign-extending imm32 to imm64. */ + r_type = (rex & REX_W) != 0 ? R_X86_64_32S : R_X86_64_32; + +rewrite_modrm_rex: + bfd_put_8 (abfd, modrm, contents + roff - 1); + + if (rex) + { + /* Move the R bit to the B bit in REX byte. */ + rex = (rex & ~rex_mask) | (rex & REX_R) >> 2; + bfd_put_8 (abfd, rex, contents + roff - 3); + } + + /* No addend for R_X86_64_32/R_X86_64_32S relocations. */ + irel->r_addend = 0; + } + + bfd_put_8 (abfd, opcode, contents + roff - 2); + } + + irel->r_info = htab->r_info (r_symndx, r_type); + + *converted = TRUE; + + return TRUE; +} /* Look through the relocs for a section during the first phase, and calculate needed space in the global offset table, procedure @@ -1562,6 +2049,7 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, 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)) @@ -1571,7 +2059,19 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, htab = elf_x86_64_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_x86_64_backend_data (abfd) == &elf_x86_64_arch_bed; @@ -1586,6 +2086,7 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, unsigned int r_type; unsigned long r_symndx; struct elf_link_hash_entry *h; + struct elf_x86_64_link_hash_entry *eh; Elf_Internal_Sym *isym; const char *name; bfd_boolean size_reloc; @@ -1597,7 +2098,7 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, { (*_bfd_error_handler) (_("%B: bad symbol index: %d"), abfd, r_symndx); - return FALSE; + goto error_return; } if (r_symndx < symtab_hdr->sh_info) @@ -1606,7 +2107,7 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, 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 (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) @@ -1614,7 +2115,7 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, h = elf_x86_64_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; @@ -1662,17 +2163,13 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, "supported in x32 mode"), abfd, x86_64_elf_howto_table[r_type].name, name); bfd_set_error (bfd_error_bad_value); - return FALSE; + goto error_return; } break; } 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: @@ -1719,18 +2216,23 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, || !bfd_set_section_alignment (htab->elf.dynobj, htab->plt_bnd, plt_bnd_align)) - return FALSE; + goto error_return; } } case R_X86_64_32S: case R_X86_64_PC64: case R_X86_64_GOTPCREL: + case R_X86_64_GOTPCRELX: + case R_X86_64_REX_GOTPCRELX: case R_X86_64_GOTPCREL64: 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; } @@ -1743,12 +2245,13 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, |= elf_gnu_symbol_ifunc; } - if (! elf_x86_64_tls_transition (info, abfd, sec, NULL, + if (! elf_x86_64_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; + eh = (struct elf_x86_64_link_hash_entry *) h; switch (r_type) { case R_X86_64_TLSLD: @@ -1757,19 +2260,10 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, case R_X86_64_TPOFF32: if (!bfd_link_executable (info) && ABI_64_P (abfd)) - { - if (h) - name = h->root.root.string; - else - name = bfd_elf_sym_name (abfd, symtab_hdr, isym, - NULL); - (*_bfd_error_handler) - (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"), - abfd, - x86_64_elf_howto_table[r_type].name, name); - bfd_set_error (bfd_error_bad_value); - return FALSE; - } + return elf_x86_64_need_pic (abfd, sec, h, symtab_hdr, isym, + &x86_64_elf_howto_table[r_type]); + if (eh != NULL) + eh->has_got_reloc = 1; break; case R_X86_64_GOTTPOFF: @@ -1779,6 +2273,8 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, case R_X86_64_GOT32: case R_X86_64_GOTPCREL: + case R_X86_64_GOTPCRELX: + case R_X86_64_REX_GOTPCRELX: case R_X86_64_TLSGD: case R_X86_64_GOT64: case R_X86_64_GOTPCREL64: @@ -1802,7 +2298,7 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, if (h != NULL) { h->got.refcount += 1; - old_tls_type = elf_x86_64_hash_entry (h)->tls_type; + old_tls_type = eh->tls_type; } else { @@ -1820,7 +2316,7 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, 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_x86_64_local_tlsdesc_gotent (abfd) = (bfd_vma *) (local_got_refcounts + symtab_hdr->sh_info); @@ -1854,14 +2350,14 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, (_("%B: '%s' accessed both as normal and thread local symbol"), abfd, name); bfd_set_error (bfd_error_bad_value); - return FALSE; + goto error_return; } } if (old_tls_type != tls_type) { - if (h != NULL) - elf_x86_64_hash_entry (h)->tls_type = tls_type; + if (eh != NULL) + eh->tls_type = tls_type; else elf_x86_64_local_got_tls_type (abfd) [r_symndx] = tls_type; } @@ -1872,13 +2368,15 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, case R_X86_64_GOTPC32: case R_X86_64_GOTPC64: create_got: + if (eh != NULL) + eh->has_got_reloc = 1; if (htab->elf.sgot == NULL) { if (htab->elf.dynobj == NULL) htab->elf.dynobj = abfd; if (!_bfd_elf_create_got_section (htab->elf.dynobj, info)) - return FALSE; + goto error_return; } break; @@ -1896,6 +2394,7 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, if (h == NULL) continue; + eh->has_got_reloc = 1; h->needs_plt = 1; h->plt.refcount += 1; break; @@ -1921,24 +2420,20 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, case R_X86_64_8: case R_X86_64_16: case R_X86_64_32S: - /* Let's help debug shared library creation. These relocs - cannot be used in shared libs. Don't error out for + /* Check relocation overflow as these relocs may lead to + run-time relocation overflow. Don't error out for sections we don't care about, such as debug sections or - non-constant sections. */ - if (bfd_link_pic (info) - && (sec->flags & SEC_ALLOC) != 0 - && (sec->flags & SEC_READONLY) != 0) - { - if (h) - name = h->root.root.string; - else - name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL); - (*_bfd_error_handler) - (_("%B: relocation %s against `%s' can not be used when making a shared object; recompile with -fPIC"), - abfd, x86_64_elf_howto_table[r_type].name, name); - bfd_set_error (bfd_error_bad_value); - return FALSE; - } + when relocation overflow check is disabled. */ + if (!info->no_reloc_overflow_check + && (bfd_link_pic (info) + || (bfd_link_executable (info) + && h != NULL + && !h->def_regular + && h->def_dynamic + && (sec->flags & SEC_READONLY) == 0)) + && (sec->flags & SEC_ALLOC) != 0) + return elf_x86_64_need_pic (abfd, sec, h, symtab_hdr, isym, + &x86_64_elf_howto_table[r_type]); /* Fall through. */ case R_X86_64_PC8: @@ -1948,7 +2443,17 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, case R_X86_64_PC64: case R_X86_64_64: pointer: - if (h != NULL && bfd_link_executable (info)) + if (eh != NULL && (sec->flags & SEC_CODE) != 0) + eh->has_non_got_reloc = 1; + /* 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 @@ -1961,9 +2466,16 @@ pointer: /* We may need a .plt entry if the function this reloc refers to is in a shared lib. */ h->plt.refcount += 1; - if (r_type != R_X86_64_PC32 - && r_type != R_X86_64_PC32_BND - && r_type != R_X86_64_PC64) + if (r_type == R_X86_64_PC32) + { + /* Since something like ".long foo - ." may be used + as pointer, make sure that PLT is used if foo is + a function defined in a shared library. */ + if ((sec->flags & SEC_CODE) == 0) + h->pointer_equality_needed = 1; + } + else if (r_type != R_X86_64_PC32_BND + && r_type != R_X86_64_PC64) { h->pointer_equality_needed = 1; /* At run-time, R_X86_64_64 can be resolved for both @@ -1974,11 +2486,7 @@ pointer: || (!ABI_64_P (abfd) && (r_type == R_X86_64_32 || r_type == R_X86_64_32S)))) - { - struct elf_x86_64_link_hash_entry *eh - = (struct elf_x86_64_link_hash_entry *) h; - eh->func_pointer_refcount += 1; - } + eh->func_pointer_refcount += 1; } } @@ -2009,7 +2517,8 @@ do_size: && (sec->flags & SEC_ALLOC) != 0 && (! IS_X86_64_PCREL_TYPE (r_type) || (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 @@ -2035,15 +2544,13 @@ do_size: abfd, /*rela?*/ TRUE); if (sreloc == NULL) - return FALSE; + goto error_return; } /* If this is a global symbol, we count the number of relocations we need for this symbol. */ if (h != NULL) - { - head = &((struct elf_x86_64_link_hash_entry *) h)->dyn_relocs; - } + head = &eh->dyn_relocs; else { /* Track dynamic relocs needed for local syms too. @@ -2055,7 +2562,7 @@ 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) @@ -2075,7 +2582,7 @@ 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; @@ -2094,7 +2601,7 @@ do_size: Reconstruct it for later use during GC. */ case R_X86_64_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 @@ -2103,7 +2610,7 @@ do_size: BFD_ASSERT (h != NULL); if (h != NULL && !bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend)) - return FALSE; + goto error_return; break; default: @@ -2141,201 +2648,73 @@ do_size: || !bfd_set_section_alignment (htab->elf.dynobj, htab->plt_got, plt_got_align)) - return FALSE; + goto error_return; } - if (r_type == R_X86_64_GOTPCREL + if ((r_type == R_X86_64_GOTPCREL + || r_type == R_X86_64_GOTPCRELX + || r_type == R_X86_64_REX_GOTPCRELX) && (h == NULL || h->type != STT_GNU_IFUNC)) - sec->need_convert_mov_to_lea = 1; + sec->need_convert_load = 1; } - return TRUE; -} - -/* Return the section that should be marked against GC for a given - relocation. */ - -static asection * -elf_x86_64_gc_mark_hook (asection *sec, - struct bfd_link_info *info, - Elf_Internal_Rela *rel, - struct elf_link_hash_entry *h, - Elf_Internal_Sym *sym) -{ - if (h != NULL) - switch (ELF32_R_TYPE (rel->r_info)) - { - case R_X86_64_GNU_VTINHERIT: - case R_X86_64_GNU_VTENTRY: - return NULL; - } - - return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym); -} - -/* Update the got entry reference counts for the section being removed. */ - -static bfd_boolean -elf_x86_64_gc_sweep_hook (bfd *abfd, struct bfd_link_info *info, - asection *sec, - const Elf_Internal_Rela *relocs) -{ - struct elf_x86_64_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_x86_64_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); - - htab = elf_x86_64_hash_table (info); - relend = relocs + sec->reloc_count; - for (rel = relocs; rel < relend; rel++) + if (elf_section_data (sec)->this_hdr.contents != contents) { - unsigned long r_symndx; - unsigned int r_type; - struct elf_link_hash_entry *h = NULL; - bfd_boolean pointer_reloc; - - r_symndx = htab->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; - } + if (!info->keep_memory) + free (contents); 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 - && ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) - { - h = elf_x86_64_get_local_sym_hash (htab, abfd, rel, FALSE); - if (h == NULL) - abort (); - } - } - - if (h) - { - struct elf_x86_64_link_hash_entry *eh; - struct elf_dyn_relocs **pp; - struct elf_dyn_relocs *p; - - eh = (struct elf_x86_64_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; - } + /* Cache the section contents for elf_link_input_bfd. */ + elf_section_data (sec)->this_hdr.contents = contents; } + } - r_type = ELF32_R_TYPE (rel->r_info); - if (! elf_x86_64_tls_transition (info, abfd, sec, NULL, - symtab_hdr, sym_hashes, - &r_type, GOT_UNKNOWN, - rel, relend, h, r_symndx)) - return FALSE; + return TRUE; - pointer_reloc = FALSE; - switch (r_type) - { - case R_X86_64_TLSLD: - if (htab->tls_ld_got.refcount > 0) - htab->tls_ld_got.refcount -= 1; - break; +error_return: + if (elf_section_data (sec)->this_hdr.contents != contents) + free (contents); + sec->check_relocs_failed = 1; + return FALSE; +} - case R_X86_64_TLSGD: - case R_X86_64_GOTPC32_TLSDESC: - case R_X86_64_TLSDESC_CALL: - case R_X86_64_GOTTPOFF: - case R_X86_64_GOT32: - case R_X86_64_GOTPCREL: - case R_X86_64_GOT64: - case R_X86_64_GOTPCREL64: - case R_X86_64_GOTPLT64: - 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; +/* Return the section that should be marked against GC for a given + relocation. */ - case R_X86_64_32: - case R_X86_64_32S: - pointer_reloc = !ABI_64_P (abfd); - goto pointer; +static asection * +elf_x86_64_gc_mark_hook (asection *sec, + struct bfd_link_info *info, + Elf_Internal_Rela *rel, + struct elf_link_hash_entry *h, + Elf_Internal_Sym *sym) +{ + if (h != NULL) + switch (ELF32_R_TYPE (rel->r_info)) + { + case R_X86_64_GNU_VTINHERIT: + case R_X86_64_GNU_VTENTRY: + return NULL; + } - case R_X86_64_64: - pointer_reloc = TRUE; - case R_X86_64_8: - case R_X86_64_16: - case R_X86_64_PC8: - case R_X86_64_PC16: - case R_X86_64_PC32: - case R_X86_64_PC32_BND: - case R_X86_64_PC64: - case R_X86_64_SIZE32: - case R_X86_64_SIZE64: -pointer: - if (bfd_link_pic (info) - && (h == NULL || h->type != STT_GNU_IFUNC)) - break; - /* Fall thru */ + return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym); +} - case R_X86_64_PLT32: - case R_X86_64_PLT32_BND: - case R_X86_64_PLTOFF64: - if (h != NULL) - { - if (h->plt.refcount > 0) - h->plt.refcount -= 1; - if (pointer_reloc && (sec->flags & SEC_READONLY) == 0) - { - struct elf_x86_64_link_hash_entry *eh - = (struct elf_x86_64_link_hash_entry *) h; - if (eh->func_pointer_refcount > 0) - eh->func_pointer_refcount -= 1; - } - } - break; +/* Remove undefined weak symbol from the dynamic symbol table if it + is resolved to 0. */ - default: - break; - } +static bfd_boolean +elf_x86_64_fixup_symbol (struct bfd_link_info *info, + struct elf_link_hash_entry *h) +{ + if (h->dynindx != -1 + && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, + elf_x86_64_hash_entry (h)->has_got_reloc, + elf_x86_64_hash_entry (h))) + { + h->dynindx = -1; + _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr, + h->dynstr_index); } - return TRUE; } @@ -2528,6 +2907,7 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) struct elf_dyn_relocs *p; const struct elf_backend_data *bed; unsigned int plt_entry_size; + bfd_boolean resolved_to_zero; if (h->root.type == bfd_link_hash_indirect) return TRUE; @@ -2541,6 +2921,10 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) bed = get_elf_backend_data (info->output_bfd); plt_entry_size = GET_PLT_ENTRY_SIZE (info->output_bfd); + resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, + eh->has_got_reloc, + eh); + /* We can't use the GOT PLT if pointer equality is needed since finish_dynamic_symbol won't clear symbol value and the dynamic linker won't update the GOT slot. We will get into an infinite @@ -2571,6 +2955,7 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) { if (_bfd_elf_allocate_ifunc_dyn_relocs (info, h, &eh->dyn_relocs, + &htab->readonly_dynrelocs_against_ifunc, plt_entry_size, plt_entry_size, GOT_ENTRY_SIZE)) @@ -2617,7 +3002,8 @@ elf_x86_64_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; @@ -2691,20 +3077,27 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) script. */ htab->elf.sgotplt->size += GOT_ENTRY_SIZE; - /* We also need to make an entry in the .rela.plt - section. */ - htab->elf.srelplt->size += bed->s->sizeof_rela; - 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 .rela.plt + section. */ + htab->elf.srelplt->size += bed->s->sizeof_rela; + htab->elf.srelplt->reloc_count++; + } } } 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; } @@ -2729,7 +3122,8 @@ elf_x86_64_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; @@ -2753,15 +3147,17 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) } dyn = htab->elf.dynamic_sections_created; /* R_X86_64_TLSGD needs one dynamic relocation if local symbol - and two if global. - R_X86_64_GOTTPOFF needs one dynamic relocation. */ + and two if global. R_X86_64_GOTTPOFF needs one dynamic + relocation. No dynamic relocation against resolved undefined + weak symbol in executable. */ if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1) || tls_type == GOT_TLS_IE) htab->elf.srelgot->size += bed->s->sizeof_rela; else if (GOT_TLS_GD_P (tls_type)) htab->elf.srelgot->size += 2 * bed->s->sizeof_rela; 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))) @@ -2808,16 +3204,16 @@ elf_x86_64_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) { if (h->root.type == bfd_link_hash_undefweak) { - if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT) + /* Undefined weak symbol is never bound locally in shared + library. */ + if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT + || resolved_to_zero) eh->dyn_relocs = NULL; - - /* Make sure undefined weak symbols are output as a dynamic - symbol in PIEs. */ else if (h->dynindx == -1 && ! h->forced_local && ! bfd_elf_link_record_dynamic_symbol (info, h)) @@ -2849,7 +3245,10 @@ elf_x86_64_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 @@ -2860,6 +3259,7 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) Undefined weak syms won't yet be marked as dynamic. */ if (h->dynindx == -1 && ! h->forced_local + && ! resolved_to_zero && ! bfd_elf_link_record_dynamic_symbol (info, h)) return FALSE; @@ -2946,25 +3346,19 @@ elf_x86_64_readonly_dynrelocs (struct elf_link_hash_entry *h, return TRUE; } -/* Convert - mov foo@GOTPCREL(%rip), %reg - to - lea foo(%rip), %reg - with the local symbol, foo. */ +/* Convert load via the GOT slot to load immediate. */ static bfd_boolean -elf_x86_64_convert_mov_to_lea (bfd *abfd, asection *sec, - struct bfd_link_info *link_info) +elf_x86_64_convert_load (bfd *abfd, asection *sec, + struct bfd_link_info *link_info) { Elf_Internal_Shdr *symtab_hdr; Elf_Internal_Rela *internal_relocs; Elf_Internal_Rela *irel, *irelend; bfd_byte *contents; struct elf_x86_64_link_hash_table *htab; - bfd_boolean changed_contents; - bfd_boolean changed_relocs; + bfd_boolean changed; bfd_signed_vma *local_got_refcounts; - bfd_vma maxpagesize; /* Don't even try to convert non-ELF outputs. */ if (!is_elf_hash_table (link_info->hash)) @@ -2972,7 +3366,7 @@ elf_x86_64_convert_mov_to_lea (bfd *abfd, asection *sec, /* Nothing to do if there is no need or no output. */ if ((sec->flags & (SEC_CODE | SEC_RELOC)) != (SEC_CODE | SEC_RELOC) - || sec->need_convert_mov_to_lea == 0 + || sec->need_convert_load == 0 || bfd_is_abs_section (sec->output_section)) return TRUE; @@ -2985,11 +3379,9 @@ elf_x86_64_convert_mov_to_lea (bfd *abfd, asection *sec, if (internal_relocs == NULL) return FALSE; + changed = FALSE; htab = elf_x86_64_hash_table (link_info); - changed_contents = FALSE; - changed_relocs = FALSE; local_got_refcounts = elf_local_got_refcounts (abfd); - maxpagesize = get_elf_backend_data (abfd)->maxpagesize; /* Get the section contents. */ if (elf_section_data (sec)->this_hdr.contents != NULL) @@ -3004,176 +3396,58 @@ elf_x86_64_convert_mov_to_lea (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 = htab->r_sym (irel->r_info); - unsigned int indx; + unsigned int r_symndx; struct elf_link_hash_entry *h; - asection *tsec; - char symtype; - bfd_vma toff, roff; - unsigned int opcode; - - if (r_type != R_X86_64_GOTPCREL) - continue; - - roff = irel->r_offset; - - if (roff < 2) - continue; - - opcode = bfd_get_8 (abfd, contents + roff - 2); + bfd_boolean converted; - /* PR ld/18591: Don't convert R_X86_64_GOTPCREL relocation if it - isn't for mov instruction. */ - if (opcode != 0x8b) + if (r_type != R_X86_64_GOTPCRELX + && r_type != R_X86_64_REX_GOTPCRELX + && r_type != R_X86_64_GOTPCREL) continue; - /* Get the symbol referred to by the reloc. */ + r_symndx = htab->r_sym (irel->r_info); if (r_symndx < symtab_hdr->sh_info) - { - Elf_Internal_Sym *isym; - - isym = bfd_sym_from_r_symndx (&htab->sym_cache, - abfd, r_symndx); - - symtype = ELF_ST_TYPE (isym->st_info); - - /* STT_GNU_IFUNC must keep R_X86_64_GOTPCREL relocation and - skip relocation against undefined symbols. */ - if (symtype == STT_GNU_IFUNC || isym->st_shndx == SHN_UNDEF) - continue; - - if (isym->st_shndx == SHN_ABS) - tsec = bfd_abs_section_ptr; - else if (isym->st_shndx == SHN_COMMON) - tsec = bfd_com_section_ptr; - else if (isym->st_shndx == SHN_X86_64_LCOMMON) - tsec = &_bfd_elf_large_com_section; - else - tsec = bfd_section_from_elf_index (abfd, isym->st_shndx); - - h = NULL; - toff = isym->st_value; - } + h = elf_x86_64_get_local_sym_hash (htab, sec->owner, + (const Elf_Internal_Rela *) irel, + FALSE); else { - indx = r_symndx - symtab_hdr->sh_info; - h = elf_sym_hashes (abfd)[indx]; - BFD_ASSERT (h != NULL); - + 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; - - /* STT_GNU_IFUNC must keep R_X86_64_GOTPCREL relocation. We also - avoid optimizing _DYNAMIC since ld.so may use its link-time - address. */ - if (h->def_regular - && h->type != STT_GNU_IFUNC - && h != htab->elf.hdynamic - && SYMBOL_REFERENCES_LOCAL (link_info, h)) - { - tsec = h->root.u.def.section; - toff = h->root.u.def.value; - symtype = h->type; - } - else - continue; } - if (tsec->sec_info_type == SEC_INFO_TYPE_MERGE) - { - /* At this stage in linking, no SEC_MERGE symbol has been - adjusted, so all references to such symbols need to be - passed through _bfd_merged_section_offset. (Later, in - relocate_section, all SEC_MERGE symbols *except* for - section symbols have been adjusted.) - - gas may reduce relocations against symbols in SEC_MERGE - sections to a relocation against the section symbol when - the original addend was zero. When the reloc is against - a section symbol we should include the addend in the - offset passed to _bfd_merged_section_offset, since the - location of interest is the original symbol. On the - other hand, an access to "sym+addend" where "sym" is not - a section symbol should not include the addend; Such an - access is presumed to be an offset from "sym"; The - location of interest is just "sym". */ - if (symtype == STT_SECTION) - toff += irel->r_addend; - - toff = _bfd_merged_section_offset (abfd, &tsec, - elf_section_data (tsec)->sec_info, - toff); - - if (symtype != STT_SECTION) - toff += irel->r_addend; - } - else - toff += irel->r_addend; + /* STT_GNU_IFUNC must keep GOTPCREL relocations. */ + if (h != NULL && h->type == STT_GNU_IFUNC) + continue; - /* Don't convert if R_X86_64_PC32 relocation overflows. */ - if (tsec->output_section == sec->output_section) - { - if ((toff - roff + 0x80000000) > 0xffffffff) - continue; - } - else + converted = FALSE; + if (!elf_x86_64_convert_load_reloc (abfd, sec, contents, irel, h, + &converted, link_info)) + goto error_return; + + if (converted) { - asection *asect; - bfd_size_type size; - - /* At this point, we don't know the load addresses of TSEC - section nor SEC section. We estimate the distrance between - SEC and TSEC. */ - size = 0; - for (asect = sec->output_section; - asect != NULL && asect != tsec->output_section; - asect = asect->next) + changed = converted; + if (h) { - asection *i; - for (i = asect->output_section->map_head.s; - i != NULL; - i = i->map_head.s) - { - size = align_power (size, i->alignment_power); - size += i->size; - } + 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; } - - /* Don't convert R_X86_64_GOTPCREL if TSEC isn't placed after - SEC. */ - if (asect == NULL) - continue; - - /* Take PT_GNU_RELRO segment into account by adding - maxpagesize. */ - if ((toff + size + maxpagesize - roff + 0x80000000) - > 0xffffffff) - continue; - } - - bfd_put_8 (abfd, 0x8d, contents + roff - 2); - irel->r_info = htab->r_info (r_symndx, R_X86_64_PC32); - changed_contents = TRUE; - changed_relocs = TRUE; - - 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; } } 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 { @@ -3184,7 +3458,7 @@ elf_x86_64_convert_mov_to_lea (bfd *abfd, asection *sec, if (elf_section_data (sec)->relocs != internal_relocs) { - if (!changed_relocs) + if (!changed) free (internal_relocs); else elf_section_data (sec)->relocs = internal_relocs; @@ -3224,19 +3498,6 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd, 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 = htab->dynamic_interpreter_size; - s->contents = (unsigned char *) htab->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) @@ -3256,7 +3517,7 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd, { struct elf_dyn_relocs *p; - if (!elf_x86_64_convert_mov_to_lea (ibfd, s, info)) + if (!elf_x86_64_convert_load (ibfd, s, info)) return FALSE; for (p = (struct elf_dyn_relocs *) @@ -3559,8 +3820,7 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd, 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")); @@ -3715,11 +3975,16 @@ elf_x86_64_relocate_section (bfd *output_bfd, bfd_vma *local_got_offsets; bfd_vma *local_tlsdesc_gotents; Elf_Internal_Rela *rel; + Elf_Internal_Rela *wrel; Elf_Internal_Rela *relend; const unsigned int plt_entry_size = GET_PLT_ENTRY_SIZE (info->output_bfd); BFD_ASSERT (is_x86_64_elf (input_bfd)); + /* Skip if check_relocs failed. */ + if (input_section->check_relocs_failed) + return FALSE; + htab = elf_x86_64_hash_table (info); if (htab == NULL) return FALSE; @@ -3730,9 +3995,9 @@ elf_x86_64_relocate_section (bfd *output_bfd, elf_x86_64_set_tls_module_base (info); - rel = relocs; + rel = wrel = relocs; relend = relocs + input_section->reloc_count; - for (; rel < relend; rel++) + for (; rel < relend; wrel++, rel++) { unsigned int r_type; reloc_howto_type *howto; @@ -3748,11 +4013,16 @@ elf_x86_64_relocate_section (bfd *output_bfd, int tls_type; asection *base_got, *resolved_plt; bfd_vma st_size; + bfd_boolean resolved_to_zero; r_type = ELF32_R_TYPE (rel->r_info); if (r_type == (int) R_X86_64_GNU_VTINHERIT || r_type == (int) R_X86_64_GNU_VTENTRY) - continue; + { + if (wrel != rel) + *wrel = *rel; + continue; + } if (r_type >= (int) R_X86_64_standard) { @@ -3810,11 +4080,29 @@ elf_x86_64_relocate_section (bfd *output_bfd, } if (sec != NULL && discarded_section (sec)) - RELOC_AGAINST_DISCARDED_SECTION (info, input_bfd, input_section, - rel, 1, relend, howto, 0, contents); + { + _bfd_clear_contents (howto, input_bfd, input_section, + contents + rel->r_offset); + wrel->r_offset = rel->r_offset; + wrel->r_info = 0; + wrel->r_addend = 0; + + /* For ld -r, remove relocations in debug sections against + sections defined in discarded sections. Not done for + eh_frame editing code expects to be present. */ + if (bfd_link_relocatable (info) + && (input_section->flags & SEC_DEBUGGING)) + wrel--; + + continue; + } if (bfd_link_relocatable (info)) - continue; + { + if (wrel != rel) + *wrel = *rel; + continue; + } if (rel->r_addend == 0 && !ABI_64_P (output_bfd)) { @@ -3891,8 +4179,7 @@ elf_x86_64_relocate_section (bfd *output_bfd, (*_bfd_error_handler) (_("%B: relocation %s against STT_GNU_IFUNC " "symbol `%s' isn't handled by %s"), input_bfd, - x86_64_elf_howto_table[r_type].name, - name, __FUNCTION__); + howto->name, name, __FUNCTION__); bfd_set_error (bfd_error_bad_value); return FALSE; @@ -3916,8 +4203,7 @@ elf_x86_64_relocate_section (bfd *output_bfd, (*_bfd_error_handler) (_("%B: relocation %s against STT_GNU_IFUNC " "symbol `%s' has non-zero addend: %d"), - input_bfd, x86_64_elf_howto_table[r_type].name, - name, rel->r_addend); + input_bfd, howto->name, name, rel->r_addend); bfd_set_error (bfd_error_bad_value); return FALSE; } @@ -3977,6 +4263,8 @@ elf_x86_64_relocate_section (bfd *output_bfd, goto do_relocation; case R_X86_64_GOTPCREL: + case R_X86_64_GOTPCRELX: + case R_X86_64_REX_GOTPCRELX: case R_X86_64_GOTPCREL64: base_got = htab->elf.sgot; off = h->got.offset; @@ -4036,6 +4324,11 @@ elf_x86_64_relocate_section (bfd *output_bfd, } } + resolved_to_zero = (eh != NULL + && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, + eh->has_got_reloc, + eh)); + /* When generating a shared object, the relocations handled here are copied into the output file to be resolved at run time. */ switch (r_type) @@ -4045,6 +4338,8 @@ elf_x86_64_relocate_section (bfd *output_bfd, /* Relocation is to the entry for this symbol in the global offset table. */ case R_X86_64_GOTPCREL: + case R_X86_64_GOTPCRELX: + case R_X86_64_REX_GOTPCRELX: case R_X86_64_GOTPCREL64: /* Use global offset table entry as symbol value. */ case R_X86_64_GOTPLT64: @@ -4150,7 +4445,10 @@ elf_x86_64_relocate_section (bfd *output_bfd, relocation = base_got->output_section->vma + base_got->output_offset + off; - if (r_type != R_X86_64_GOTPCREL && r_type != R_X86_64_GOTPCREL64) + if (r_type != R_X86_64_GOTPCREL + && r_type != R_X86_64_GOTPCRELX + && r_type != R_X86_64_REX_GOTPCRELX + && r_type != R_X86_64_GOTPCREL64) relocation -= htab->elf.sgotplt->output_section->vma - htab->elf.sgotplt->output_offset; @@ -4311,13 +4609,16 @@ elf_x86_64_relocate_section (bfd *output_bfd, case R_X86_64_PC32: case R_X86_64_PC32_BND: /* Don't complain about -fPIC if the symbol is undefined when - building executable. */ - if (bfd_link_pic (info) - && (input_section->flags & SEC_ALLOC) != 0 + building executable unless it is unresolved weak symbol. */ + if ((input_section->flags & SEC_ALLOC) != 0 && (input_section->flags & SEC_READONLY) != 0 && h != NULL - && !(bfd_link_executable (info) - && h->root.type == bfd_link_hash_undefined)) + && ((bfd_link_executable (info) + && h->root.type == bfd_link_hash_undefweak + && !resolved_to_zero) + || (bfd_link_pic (info) + && !(bfd_link_pie (info) + && h->root.type == bfd_link_hash_undefined)))) { bfd_boolean fail = FALSE; bfd_boolean branch @@ -4331,7 +4632,7 @@ elf_x86_64_relocate_section (bfd *output_bfd, defined locally or for a branch. */ fail = !h->def_regular && !branch; } - else if (!(bfd_link_executable (info) + else if (!(bfd_link_pie (info) && (h->needs_copy || eh->needs_copy))) { /* Symbol doesn't need copy reloc and isn't referenced @@ -4342,39 +4643,8 @@ elf_x86_64_relocate_section (bfd *output_bfd, } if (fail) - { - const char *fmt; - const char *v; - const char *pic = ""; - - switch (ELF_ST_VISIBILITY (h->other)) - { - case STV_HIDDEN: - v = _("hidden symbol"); - break; - case STV_INTERNAL: - v = _("internal symbol"); - break; - case STV_PROTECTED: - v = _("protected symbol"); - break; - default: - v = _("symbol"); - pic = _("; recompile with -fPIC"); - break; - } - - if (h->def_regular) - fmt = _("%B: relocation %s against %s `%s' can not be used when making a shared object%s"); - else - fmt = _("%B: relocation %s against undefined %s `%s' can not be used when making a shared object%s"); - - (*_bfd_error_handler) (fmt, input_bfd, - x86_64_elf_howto_table[r_type].name, - v, h->root.root.string, pic); - bfd_set_error (bfd_error_bad_value); - return FALSE; - } + return elf_x86_64_need_pic (input_bfd, input_section, + h, NULL, NULL, howto); } /* Fall through. */ @@ -4393,17 +4663,19 @@ direct: /* Don't copy a pc-relative relocation into the output file if the symbol needs copy reloc or the symbol is undefined when building executable. Copy dynamic function pointer - relocations. */ + relocations. Don't generate dynamic relocations against + resolved undefined weak symbols in PIE. */ if ((bfd_link_pic (info) - && !(bfd_link_executable (info) + && !(bfd_link_pie (info) && h != NULL && (h->needs_copy || eh->needs_copy || h->root.type == bfd_link_hash_undefined) && IS_X86_64_PCREL_TYPE (r_type)) && (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) + || h->root.type != bfd_link_hash_undefweak)) && ((! IS_X86_64_PCREL_TYPE (r_type) && r_type != R_X86_64_SIZE32 && r_type != R_X86_64_SIZE64) @@ -4412,10 +4684,13 @@ direct: && !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->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_undefined))) { Elf_Internal_Rela outrel; @@ -4447,8 +4722,8 @@ direct: else if (h != NULL && h->dynindx != -1 && (IS_X86_64_PCREL_TYPE (r_type) - || ! bfd_link_pic (info) - || ! SYMBOLIC_BIND (info, h) + || !(bfd_link_executable (info) + || SYMBOLIC_BIND (info, h)) || ! h->def_regular)) { outrel.r_info = htab->r_info (h->dynindx, r_type); @@ -4456,8 +4731,12 @@ direct: } else { - /* This symbol is local, or marked to become local. */ - if (r_type == htab->pointer_r_type) + /* This symbol is local, or marked to become local. + When relocation overflow check is disabled, we + convert R_X86_64_32 to dynamic R_X86_64_RELATIVE. */ + if (r_type == htab->pointer_r_type + || (r_type == R_X86_64_32 + && info->no_reloc_overflow_check)) { relocate = TRUE; outrel.r_info = htab->r_info (0, R_X86_64_RELATIVE); @@ -4487,16 +4766,16 @@ direct: "symbol `%s' at 0x%lx in section `%A' is " "out of range"), input_bfd, input_section, addend, - x86_64_elf_howto_table[r_type].name, - name, (unsigned long) rel->r_offset); + howto->name, name, + (unsigned long) rel->r_offset); else (*_bfd_error_handler) (_("%B: addend 0x%x in relocation %s against " "symbol `%s' at 0x%lx in section `%A' is " "out of range"), input_bfd, input_section, addend, - x86_64_elf_howto_table[r_type].name, - name, (unsigned long) rel->r_offset); + howto->name, name, + (unsigned long) rel->r_offset); bfd_set_error (bfd_error_bad_value); return FALSE; } @@ -4570,7 +4849,7 @@ direct: 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_X86_64_TPOFF32) @@ -4624,6 +4903,7 @@ direct: contents + roff + 8 + largepic); /* Skip R_X86_64_PC32/R_X86_64_PLT32/R_X86_64_PLTOFF64. */ rel++; + wrel++; continue; } else if (ELF32_R_TYPE (rel->r_info) == R_X86_64_GOTPC32_TLSDESC) @@ -4906,6 +5186,7 @@ direct: contents + roff + 8 + largepic); /* Skip R_X86_64_PLT32/R_X86_64_PLTOFF64. */ rel++; + wrel++; continue; } else if (ELF32_R_TYPE (rel->r_info) == R_X86_64_GOTPC32_TLSDESC) @@ -4955,8 +5236,8 @@ direct: if (! elf_x86_64_tls_transition (info, input_bfd, input_section, contents, symtab_hdr, sym_hashes, - &r_type, GOT_UNKNOWN, - rel, relend, h, r_symndx)) + &r_type, GOT_UNKNOWN, rel, + relend, h, r_symndx, TRUE)) return FALSE; if (r_type != R_X86_64_TLSLD) @@ -4990,6 +5271,7 @@ direct: "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0", 12); /* Skip R_X86_64_PC32/R_X86_64_PLT32/R_X86_64_PLTOFF64. */ rel++; + wrel++; continue; } @@ -5106,6 +5388,29 @@ check_relocation_error: return FALSE; } } + + if (wrel != rel) + *wrel = *rel; + } + + if (wrel != rel) + { + Elf_Internal_Shdr *rel_hdr; + size_t deleted = rel - wrel; + + rel_hdr = _bfd_elf_single_rel_hdr (input_section->output_section); + rel_hdr->sh_size -= rel_hdr->sh_entsize * deleted; + if (rel_hdr->sh_size == 0) + { + /* It is too late to remove an empty reloc section. Leave + one NONE reloc. + ??? What is wrong with an empty section??? */ + rel_hdr->sh_size = rel_hdr->sh_entsize; + deleted -= 1; + } + rel_hdr = _bfd_elf_single_rel_hdr (input_section); + rel_hdr->sh_size -= rel_hdr->sh_entsize * deleted; + input_section->reloc_count -= deleted; } return TRUE; @@ -5118,12 +5423,13 @@ static bfd_boolean elf_x86_64_finish_dynamic_symbol (bfd *output_bfd, struct bfd_link_info *info, struct elf_link_hash_entry *h, - Elf_Internal_Sym *sym ATTRIBUTE_UNUSED) + Elf_Internal_Sym *sym) { struct elf_x86_64_link_hash_table *htab; const struct elf_x86_64_backend_data *abed; bfd_boolean use_plt_bnd; struct elf_x86_64_link_hash_entry *eh; + bfd_boolean local_undefweak; htab = elf_x86_64_hash_table (info); if (htab == NULL) @@ -5138,6 +5444,13 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd, eh = (struct elf_x86_64_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; @@ -5167,6 +5480,7 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd, /* This symbol has an entry in the procedure linkage table. Set it up. */ if ((h->dynindx == -1 + && !local_undefweak && !((h->forced_local || bfd_link_executable (info)) && h->def_regular && h->type == STT_GNU_IFUNC)) @@ -5267,60 +5581,67 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd, resolved_plt->contents + plt_offset + plt_got_offset); /* Fill in the entry in the global offset table, initially this - points to the second part of the PLT entry. */ - bfd_put_64 (output_bfd, (plt->output_section->vma - + plt->output_offset - + h->plt.offset + abed->plt_lazy_offset), - gotplt->contents + got_offset); - - /* Fill in the entry in the .rela.plt section. */ - rela.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_X86_64_IRELATIVE instead of R_X86_64_JUMP_SLOT. */ - rela.r_info = htab->r_info (0, R_X86_64_IRELATIVE); - rela.r_addend = (h->root.u.def.value - + h->root.u.def.section->output_section->vma - + h->root.u.def.section->output_offset); - /* R_X86_64_IRELATIVE comes last. */ - plt_index = htab->next_irelative_index--; - } - else + points to the second part of the PLT entry. Leave the entry + as zero for undefined weak symbol in PIE. No PLT relocation + against undefined weak symbol in PIE. */ + if (!local_undefweak) { - rela.r_info = htab->r_info (h->dynindx, R_X86_64_JUMP_SLOT); - rela.r_addend = 0; - plt_index = htab->next_jump_slot_index++; - } + bfd_put_64 (output_bfd, (plt->output_section->vma + + plt->output_offset + + h->plt.offset + + abed->plt_lazy_offset), + gotplt->contents + got_offset); + + /* Fill in the entry in the .rela.plt section. */ + rela.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_X86_64_IRELATIVE instead of R_X86_64_JUMP_SLOT. */ + rela.r_info = htab->r_info (0, R_X86_64_IRELATIVE); + rela.r_addend = (h->root.u.def.value + + h->root.u.def.section->output_section->vma + + h->root.u.def.section->output_offset); + /* R_X86_64_IRELATIVE comes last. */ + plt_index = htab->next_irelative_index--; + } + else + { + rela.r_info = htab->r_info (h->dynindx, R_X86_64_JUMP_SLOT); + rela.r_addend = 0; + plt_index = htab->next_jump_slot_index++; + } - /* Don't fill PLT entry for static executables. */ - if (plt == htab->elf.splt) - { - bfd_vma plt0_offset = h->plt.offset + plt_plt_insn_end; - - /* Put relocation index. */ - bfd_put_32 (output_bfd, plt_index, - plt->contents + h->plt.offset + abed->plt_reloc_offset); - - /* Put offset for jmp .PLT0 and check for overflow. We don't - check relocation index for overflow since branch displacement - will overflow first. */ - if (plt0_offset > 0x80000000) - info->callbacks->einfo (_("%F%B: branch displacement overflow in PLT entry for `%s'\n"), - output_bfd, h->root.root.string); - bfd_put_32 (output_bfd, - plt0_offset, - plt->contents + h->plt.offset + plt_plt_offset); - } + /* Don't fill PLT entry for static executables. */ + if (plt == htab->elf.splt) + { + bfd_vma plt0_offset = h->plt.offset + plt_plt_insn_end; + + /* Put relocation index. */ + bfd_put_32 (output_bfd, plt_index, + (plt->contents + h->plt.offset + + abed->plt_reloc_offset)); + + /* Put offset for jmp .PLT0 and check for overflow. We don't + check relocation index for overflow since branch displacement + will overflow first. */ + if (plt0_offset > 0x80000000) + info->callbacks->einfo (_("%F%B: branch displacement overflow in PLT entry for `%s'\n"), + output_bfd, h->root.root.string); + bfd_put_32 (output_bfd, - plt0_offset, + plt->contents + h->plt.offset + plt_plt_offset); + } - bed = get_elf_backend_data (output_bfd); - loc = relplt->contents + plt_index * bed->s->sizeof_rela; - bed->s->swap_reloca_out (output_bfd, &rela, loc); + bed = get_elf_backend_data (output_bfd); + loc = relplt->contents + plt_index * bed->s->sizeof_rela; + bed->s->swap_reloca_out (output_bfd, &rela, loc); + } } else if (eh->plt_got.offset != (bfd_vma) -1) { @@ -5382,7 +5703,8 @@ elf_x86_64_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)) { @@ -5399,9 +5721,12 @@ elf_x86_64_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_x86_64_hash_entry (h)->tls_type) - && elf_x86_64_hash_entry (h)->tls_type != GOT_TLS_IE) + && elf_x86_64_hash_entry (h)->tls_type != GOT_TLS_IE + && !local_undefweak) { Elf_Internal_Rela rela; @@ -5507,6 +5832,25 @@ elf_x86_64_finish_local_dynamic_symbol (void **slot, void *inf) info, 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_x86_64_finish_dynamic_symbol. */ + +static bfd_boolean +elf_x86_64_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_x86_64_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. */ @@ -5518,19 +5862,23 @@ elf_x86_64_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_x86_64_link_hash_table *htab = elf_x86_64_hash_table (info); - unsigned long r_symndx = htab->r_sym (rela->r_info); - Elf_Internal_Sym sym; - - if (htab->elf.dynsym == NULL - || !bed->s->swap_symbol_in (abfd, - (htab->elf.dynsym->contents - + r_symndx * bed->s->sizeof_sym), - 0, &sym)) - abort (); - /* Check relocation against STT_GNU_IFUNC symbol. */ - if (ELF_ST_TYPE (sym.st_info) == STT_GNU_IFUNC) - return reloc_class_ifunc; + if (htab->elf.dynsym != NULL + && htab->elf.dynsym->contents != NULL) + { + /* Check relocation against STT_GNU_IFUNC symbol if there are + dynamic symbols. */ + unsigned long r_symndx = htab->r_sym (rela->r_info); + Elf_Internal_Sym sym; + if (!bed->s->swap_symbol_in (abfd, + (htab->elf.dynsym->contents + + r_symndx * bed->s->sizeof_sym), + 0, &sym)) + abort (); + + if (ELF_ST_TYPE (sym.st_info) == STT_GNU_IFUNC) + return reloc_class_ifunc; + } switch ((int) ELF32_R_TYPE (rela->r_info)) { @@ -5776,6 +6124,12 @@ elf_x86_64_finish_dynamic_sections (bfd *output_bfd, elf_x86_64_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_x86_64_pie_finish_undefweak_symbol, + info); + return TRUE; } @@ -5852,19 +6206,20 @@ bad_return: reloc_index = H_GET_32 (abfd, (plt_contents + plt_offset + bed->plt_reloc_offset)); - if (reloc_index >= count) - abort (); - if (plt_bnd) + if (reloc_index < count) { - /* This is the index in .plt section. */ - long plt_index = plt_offset / bed->plt_entry_size; - /* Store VMA + the offset in .plt.bnd section. */ - plt_sym_val[reloc_index] = - (plt_bnd->vma - + (plt_index - 1) * sizeof (elf_x86_64_legacy_plt2_entry)); + if (plt_bnd) + { + /* This is the index in .plt section. */ + long plt_index = plt_offset / bed->plt_entry_size; + /* Store VMA + the offset in .plt.bnd section. */ + plt_sym_val[reloc_index] = + (plt_bnd->vma + + (plt_index - 1) * sizeof (elf_x86_64_legacy_plt2_entry)); + } + else + plt_sym_val[reloc_index] = plt->vma + plt_offset; } - else - plt_sym_val[reloc_index] = plt->vma + plt_offset; plt_offset += bed->plt_entry_size; /* PR binutils/18437: Skip extra relocations in the .rela.plt @@ -5922,7 +6277,7 @@ elf_x86_64_section_from_shdr (bfd *abfd, Elf_Internal_Shdr *hdr, static bfd_boolean elf_x86_64_add_symbol_hook (bfd *abfd, - struct bfd_link_info *info, + struct bfd_link_info *info ATTRIBUTE_UNUSED, Elf_Internal_Sym *sym, const char **namep ATTRIBUTE_UNUSED, flagword *flagsp ATTRIBUTE_UNUSED, @@ -5951,12 +6306,6 @@ elf_x86_64_add_symbol_hook (bfd *abfd, return TRUE; } - 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; } @@ -6129,6 +6478,7 @@ static const struct bfd_elf_special_section #define elf_backend_rela_normal 1 #define elf_backend_plt_alignment 4 #define elf_backend_extern_protected_data 1 +#define elf_backend_caches_rawsize 1 #define elf_info_to_howto elf_x86_64_info_to_howto @@ -6146,7 +6496,6 @@ static const struct bfd_elf_special_section #define elf_backend_finish_dynamic_sections elf_x86_64_finish_dynamic_sections #define elf_backend_finish_dynamic_symbol elf_x86_64_finish_dynamic_symbol #define elf_backend_gc_mark_hook elf_x86_64_gc_mark_hook -#define elf_backend_gc_sweep_hook elf_x86_64_gc_sweep_hook #define elf_backend_grok_prstatus elf_x86_64_grok_prstatus #define elf_backend_grok_psinfo elf_x86_64_grok_psinfo #ifdef CORE_HEADER @@ -6184,6 +6533,10 @@ static const struct bfd_elf_special_section elf_x86_64_additional_program_headers #define elf_backend_hash_symbol \ elf_x86_64_hash_symbol +#define elf_backend_omit_section_dynsym \ + ((bfd_boolean (*) (bfd *, struct bfd_link_info *, asection *)) bfd_true) +#define elf_backend_fixup_symbol \ + elf_x86_64_fixup_symbol #include "elf64-target.h" @@ -6233,16 +6586,33 @@ static const struct bfd_elf_special_section /* The 64-bit static TLS arena size is rounded to the nearest 16-byte boundary. */ -#undef elf_backend_static_tls_alignment +#undef elf_backend_static_tls_alignment #define elf_backend_static_tls_alignment 16 /* 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 + +static bfd_boolean +elf64_x86_64_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; +} + +#undef elf_backend_copy_special_section_fields +#define elf_backend_copy_special_section_fields elf64_x86_64_copy_solaris_special_section_fields + #include "elf64-target.h" /* Native Client support. */ @@ -6274,6 +6644,8 @@ elf64_x86_64_nacl_elf_object_p (bfd *abfd) #undef elf_backend_static_tls_alignment #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 /* NaCl uses substantially different PLT entries for the same effects. */