diff options
| -rw-r--r-- | bfd/ChangeLog | 30 | ||||
| -rw-r--r-- | bfd/elf32-i386.c | 222 | ||||
| -rw-r--r-- | bfd/elf64-x86-64.c | 239 | ||||
| -rw-r--r-- | ld/ChangeLog | 5 | ||||
| -rw-r--r-- | ld/emulparams/elf_i386.sh | 4 | ||||
| -rw-r--r-- | ld/emulparams/elf_x86_64.sh | 5 | ||||
| -rw-r--r-- | ld/testsuite/ChangeLog | 9 | ||||
| -rw-r--r-- | ld/testsuite/ld-i386/i386.exp | 18 | ||||
| -rw-r--r-- | ld/testsuite/ld-i386/plt-main.rd | 4 | ||||
| -rw-r--r-- | ld/testsuite/ld-x86-64/plt-main-bnd.dd | 7 | ||||
| -rw-r--r-- | ld/testsuite/ld-x86-64/plt-main.rd | 4 | ||||
| -rw-r--r-- | ld/testsuite/ld-x86-64/x86-64.exp | 65 |
12 files changed, 543 insertions, 69 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 71d34fe..6f9861b 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,33 @@ +2014-11-25 H.J. Lu <hongjiu.lu@intel.com> + + * elf32-i386.c (elf_i386_got_plt_entry): New. + (elf_i386_pic_got_plt_entry): Likewise. + (elf_i386_link_hash_entry): Add plt_got. + (elf_i386_link_hash_table): Likewise. + (elf_i386_link_hash_newfunc): Initialize plt_got.offset to -1. + (elf_i386_get_local_sym_hash): Likewise. + (elf_i386_check_relocs): Create the GOT PLT if there are both + PLT and GOT references when the regular PLT is used. + (elf_i386_allocate_dynrelocs): Use the GOT PLT if there are + both PLT and GOT references unless pointer equality is needed. + (elf_i386_relocate_section): Also check the GOT PLT when + resolving R_386_PLT32. + (elf_i386_finish_dynamic_symbol): Use the GOT PLT if it is + available. + + * elf64-x86-64.c (elf_x86_64_link_hash_entry): Add plt_got. + (elf_x86_64_link_hash_table): Likewise. + (elf_x86_64_link_hash_newfunc): Initialize plt_got.offset to -1. + (elf_x86_64_get_local_sym_hash): Likewise. + (elf_x86_64_check_relocs): Create the GOT PLT if there are both + PLT and GOT references when the regular PLT is used. + (elf_x86_64_allocate_dynrelocs): Use the GOT PLT if there are + both PLT and GOT references unless pointer equality is needed. + (elf_x86_64_relocate_section): Also check the GOT PLT when + resolving R_X86_64_PLT32. + (elf_x86_64_finish_dynamic_symbol): Use the GOT PLT if it is + available. + 2014-11-24 H.J. Lu <hongjiu.lu@intel.com> * configure: Regenerated. diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index 64cdece..5c35d65 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -580,6 +580,24 @@ static const bfd_byte elf_i386_pic_plt_entry[PLT_ENTRY_SIZE] = 0, 0, 0, 0 /* replaced with offset to start of .plt. */ }; +/* Entries in the GOT procedure linkage table look like this. */ + +static const bfd_byte elf_i386_got_plt_entry[8] = +{ + 0xff, 0x25, /* jmp indirect */ + 0, 0, 0, 0, /* replaced with offset of this symbol in .got. */ + 0x66, 0x90 /* xchg %ax,%ax */ +}; + +/* Entries in the PIC GOT procedure linkage table look like this. */ + +static const bfd_byte elf_i386_pic_got_plt_entry[8] = +{ + 0xff, 0xa3, /* jmp *offset(%ebx) */ + 0, 0, 0, 0, /* replaced with offset of this symbol in .got. */ + 0x66, 0x90 /* xchg %ax,%ax */ +}; + /* .eh_frame covering the .plt section. */ static const bfd_byte elf_i386_eh_frame_plt[] = @@ -736,6 +754,10 @@ struct elf_i386_link_hash_entry (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type)) unsigned char tls_type; + /* Information about the GOT PLT entry. Filled when there are both + GOT and PLT relocations against the same function. */ + union gotplt_union plt_got; + /* Offset of the GOTPLT entry reserved for the TLS descriptor, starting at the end of the jump table. */ bfd_vma tlsdesc_got; @@ -785,6 +807,7 @@ struct elf_i386_link_hash_table asection *sdynbss; asection *srelbss; asection *plt_eh_frame; + asection *plt_got; union { @@ -854,6 +877,7 @@ elf_i386_link_hash_newfunc (struct bfd_hash_entry *entry, eh = (struct elf_i386_link_hash_entry *) entry; eh->dyn_relocs = NULL; eh->tls_type = GOT_UNKNOWN; + eh->plt_got.offset = (bfd_vma) -1; eh->tlsdesc_got = (bfd_vma) -1; } @@ -922,6 +946,7 @@ elf_i386_get_local_sym_hash (struct elf_i386_link_hash_table *htab, ret->elf.indx = sec->id; ret->elf.dynstr_index = ELF32_R_SYM (rel->r_info); ret->elf.dynindx = -1; + ret->plt_got.offset = (bfd_vma) -1; *slot = ret; } return &ret->elf; @@ -1418,6 +1443,7 @@ elf_i386_check_relocs (bfd *abfd, const Elf_Internal_Rela *rel; const Elf_Internal_Rela *rel_end; asection *sreloc; + bfd_boolean use_plt_got; if (info->relocatable) return TRUE; @@ -1428,6 +1454,10 @@ elf_i386_check_relocs (bfd *abfd, if (htab == NULL) return FALSE; + use_plt_got = (!get_elf_i386_backend_data (abfd)->is_vxworks + && (get_elf_i386_backend_data (abfd) + == &elf_i386_arch_bed)); + symtab_hdr = &elf_symtab_hdr (abfd); sym_hashes = elf_sym_hashes (abfd); @@ -1819,6 +1849,39 @@ do_size: default: break; } + + if (use_plt_got + && h != NULL + && h->plt.refcount > 0 + && h->got.refcount > 0 + && htab->plt_got == NULL) + { + /* Create the GOT procedure linkage table. */ + unsigned int plt_got_align; + const struct elf_backend_data *bed; + + bed = get_elf_backend_data (info->output_bfd); + BFD_ASSERT (sizeof (elf_i386_got_plt_entry) == 8 + && (sizeof (elf_i386_got_plt_entry) + == sizeof (elf_i386_pic_got_plt_entry))); + plt_got_align = 3; + + if (htab->elf.dynobj == NULL) + htab->elf.dynobj = abfd; + htab->plt_got + = bfd_make_section_anyway_with_flags (htab->elf.dynobj, + ".plt.got", + (bed->dynamic_sec_flags + | SEC_ALLOC + | SEC_CODE + | SEC_LOAD + | SEC_READONLY)); + if (htab->plt_got == NULL + || !bfd_set_section_alignment (htab->elf.dynobj, + htab->plt_got, + plt_got_align)) + return FALSE; + } } return TRUE; @@ -2191,6 +2254,24 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) plt_entry_size = GET_PLT_ENTRY_SIZE (info->output_bfd); + /* 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 + loop at run-time. */ + if (htab->plt_got != NULL + && h->type != STT_GNU_IFUNC + && !h->pointer_equality_needed + && h->plt.refcount > 0 + && h->got.refcount > 0) + { + /* Don't use the regular PLT if there are both GOT and GOTPLT + reloctions. */ + h->plt.offset = (bfd_vma) -1; + + /* Use the GOT PLT. */ + eh->plt_got.refcount = 1; + } + /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it here if it is defined and referenced in a non-shared object. */ if (h->type == STT_GNU_IFUNC @@ -2199,8 +2280,10 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) plt_entry_size, plt_entry_size, 4); else if (htab->elf.dynamic_sections_created - && h->plt.refcount > 0) + && (h->plt.refcount > 0 || eh->plt_got.refcount > 0)) { + bfd_boolean use_plt_got = eh->plt_got.refcount > 0; + /* Make sure this symbol is output as a dynamic symbol. Undefined weak syms won't yet be marked as dynamic. */ if (h->dynindx == -1 @@ -2214,13 +2297,17 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h)) { asection *s = htab->elf.splt; + asection *got_s = htab->plt_got; /* If this is the first .plt entry, make room for the special first entry. */ if (s->size == 0) s->size = plt_entry_size; - h->plt.offset = s->size; + if (use_plt_got) + eh->plt_got.offset = got_s->size; + else + h->plt.offset = s->size; /* If this symbol is not defined in a regular file, and we are not generating a shared library, then set the symbol to this @@ -2230,20 +2317,36 @@ elf_i386_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) if (! info->shared && !h->def_regular) { - h->root.u.def.section = s; - h->root.u.def.value = h->plt.offset; + if (use_plt_got) + { + /* We need to make a call to the entry of the GOT PLT + instead of regular PLT entry. */ + h->root.u.def.section = got_s; + h->root.u.def.value = eh->plt_got.offset; + } + else + { + h->root.u.def.section = s; + h->root.u.def.value = h->plt.offset; + } } /* Make room for this entry. */ - s->size += plt_entry_size; + if (use_plt_got) + got_s->size += sizeof (elf_i386_got_plt_entry); + else + { + s->size += plt_entry_size; - /* We also need to make an entry in the .got.plt section, which - will be placed in the .got section by the linker script. */ - htab->elf.sgotplt->size += 4; + /* We also need to make an entry in the .got.plt section, + which will be placed in the .got section by the linker + script. */ + htab->elf.sgotplt->size += 4; - /* We also need to make an entry in the .rel.plt section. */ - htab->elf.srelplt->size += sizeof (Elf32_External_Rel); - htab->elf.srelplt->reloc_count++; + /* We also need to make an entry in the .rel.plt section. */ + htab->elf.srelplt->size += sizeof (Elf32_External_Rel); + htab->elf.srelplt->reloc_count++; + } if (get_elf_i386_backend_data (info->output_bfd)->is_vxworks && !info->shared) @@ -2886,6 +2989,7 @@ elf_i386_size_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info) else if (s == htab->elf.sgotplt || s == htab->elf.iplt || s == htab->elf.igotplt + || s == htab->plt_got || s == htab->plt_eh_frame || s == htab->sdynbss) { @@ -3183,15 +3287,17 @@ elf_i386_relocate_section (bfd *output_bfd, reloc_howto_type *howto; unsigned long r_symndx; struct elf_link_hash_entry *h; + struct elf_i386_link_hash_entry *eh; Elf_Internal_Sym *sym; asection *sec; - bfd_vma off, offplt; + bfd_vma off, offplt, plt_offset; bfd_vma relocation; bfd_boolean unresolved_reloc; bfd_reloc_status_type r; unsigned int indx; int tls_type; bfd_vma st_size; + asection *resolved_plt; r_type = ELF32_R_TYPE (rel->r_info); if (r_type == R_386_GNU_VTINHERIT @@ -3665,7 +3771,9 @@ elf_i386_relocate_section (bfd *output_bfd, if (h == NULL) break; - if (h->plt.offset == (bfd_vma) -1 + eh = (struct elf_i386_link_hash_entry *) h; + if ((h->plt.offset == (bfd_vma) -1 + && eh->plt_got.offset == (bfd_vma) -1) || htab->elf.splt == NULL) { /* We didn't make a PLT entry for this symbol. This @@ -3674,9 +3782,20 @@ elf_i386_relocate_section (bfd *output_bfd, break; } - relocation = (htab->elf.splt->output_section->vma - + htab->elf.splt->output_offset - + h->plt.offset); + if (h->plt.offset != (bfd_vma) -1) + { + resolved_plt = htab->elf.splt; + plt_offset = h->plt.offset; + } + else + { + resolved_plt = htab->plt_got; + plt_offset = eh->plt_got.offset; + } + + relocation = (resolved_plt->output_section->vma + + resolved_plt->output_offset + + plt_offset); unresolved_reloc = FALSE; break; @@ -4427,6 +4546,7 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd, struct elf_i386_link_hash_table *htab; unsigned plt_entry_size; const struct elf_i386_backend_data *abed; + struct elf_i386_link_hash_entry *eh; htab = elf_i386_hash_table (info); if (htab == NULL) @@ -4435,6 +4555,8 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd, abed = get_elf_i386_backend_data (output_bfd); plt_entry_size = GET_PLT_ENTRY_SIZE (output_bfd); + eh = (struct elf_i386_link_hash_entry *) h; + if (h->plt.offset != (bfd_vma) -1) { bfd_vma plt_index; @@ -4599,21 +4721,65 @@ elf_i386_finish_dynamic_symbol (bfd *output_bfd, plt->contents + h->plt.offset + abed->plt->plt_plt_offset); } + } + else if (eh->plt_got.offset != (bfd_vma) -1) + { + bfd_vma got_offset, plt_offset; + asection *plt, *got, *gotplt; + const bfd_byte *got_plt_entry; + + /* Offset of displacement of the indirect jump. */ + bfd_vma plt_got_offset = 2; - if (!h->def_regular) + /* Set the entry in the GOT procedure linkage table. */ + plt = htab->plt_got; + got = htab->elf.sgot; + gotplt = htab->elf.sgotplt; + got_offset = h->got.offset; + + if (got_offset == (bfd_vma) -1 + || plt == NULL + || got == NULL + || gotplt == NULL) + abort (); + + /* Fill in the entry in the GOT procedure linkage table. */ + if (! info->shared) { - /* Mark the symbol as undefined, rather than as defined in - the .plt section. Leave the value if there were any - relocations where pointer equality matters (this is a clue - for the dynamic linker, to make function pointer - comparisons work between an application and shared - library), otherwise set it to zero. If a function is only - called from a binary, there is no need to slow down - shared libraries because of that. */ - sym->st_shndx = SHN_UNDEF; - if (!h->pointer_equality_needed) - sym->st_value = 0; + got_plt_entry = elf_i386_got_plt_entry; + got_offset += got->output_section->vma + got->output_offset; } + else + { + got_plt_entry = elf_i386_pic_got_plt_entry; + got_offset += (got->output_section->vma + + got->output_offset + - gotplt->output_section->vma + - gotplt->output_offset); + } + + plt_offset = eh->plt_got.offset; + memcpy (plt->contents + plt_offset, got_plt_entry, + sizeof (elf_i386_got_plt_entry)); + bfd_put_32 (output_bfd, got_offset, + plt->contents + plt_offset + plt_got_offset); + } + + if (!h->def_regular + && (h->plt.offset != (bfd_vma) -1 + || eh->plt_got.offset != (bfd_vma) -1)) + { + /* Mark the symbol as undefined, rather than as defined in + the .plt section. Leave the value if there were any + relocations where pointer equality matters (this is a clue + for the dynamic linker, to make function pointer + comparisons work between an application and shared + library), otherwise set it to zero. If a function is only + called from a binary, there is no need to slow down + shared libraries because of that. */ + sym->st_shndx = SHN_UNDEF; + if (!h->pointer_equality_needed) + sym->st_value = 0; } if (h->got.offset != (bfd_vma) -1 diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index 66c24e8..b10c0c1 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -760,6 +760,10 @@ struct elf_x86_64_link_hash_entry /* TRUE if symbol has at least one BND relocation. */ bfd_boolean has_bnd_reloc; + /* Information about the GOT PLT entry. Filled when there are both + GOT and PLT relocations against the same function. */ + union gotplt_union plt_got; + /* Information about the second PLT entry. Filled when has_bnd_reloc is set. */ union gotplt_union plt_bnd; @@ -815,6 +819,7 @@ struct elf_x86_64_link_hash_table asection *srelbss; asection *plt_eh_frame; asection *plt_bnd; + asection *plt_got; union { @@ -894,6 +899,7 @@ elf_x86_64_link_hash_newfunc (struct bfd_hash_entry *entry, eh->tls_type = GOT_UNKNOWN; eh->has_bnd_reloc = FALSE; eh->plt_bnd.offset = (bfd_vma) -1; + eh->plt_got.offset = (bfd_vma) -1; eh->tlsdesc_got = (bfd_vma) -1; } @@ -962,6 +968,7 @@ elf_x86_64_get_local_sym_hash (struct elf_x86_64_link_hash_table *htab, ret->elf.indx = sec->id; ret->elf.dynstr_index = htab->r_sym (rel->r_info); ret->elf.dynindx = -1; + ret->plt_got.offset = (bfd_vma) -1; *slot = ret; } return &ret->elf; @@ -1514,6 +1521,7 @@ 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_boolean use_plt_got; if (info->relocatable) return TRUE; @@ -1524,6 +1532,8 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, if (htab == NULL) return FALSE; + use_plt_got = get_elf_x86_64_backend_data (abfd) == &elf_x86_64_arch_bed; + symtab_hdr = &elf_symtab_hdr (abfd); sym_hashes = elf_sym_hashes (abfd); @@ -2039,6 +2049,39 @@ do_size: default: break; } + + if (use_plt_got + && h != NULL + && h->plt.refcount > 0 + && h->got.refcount > 0 + && htab->plt_got == NULL) + { + /* Create the GOT procedure linkage table. */ + unsigned int plt_got_align; + const struct elf_backend_data *bed; + + bed = get_elf_backend_data (info->output_bfd); + BFD_ASSERT (sizeof (elf_x86_64_legacy_plt2_entry) == 8 + && (sizeof (elf_x86_64_bnd_plt2_entry) + == sizeof (elf_x86_64_legacy_plt2_entry))); + plt_got_align = 3; + + if (htab->elf.dynobj == NULL) + htab->elf.dynobj = abfd; + htab->plt_got + = bfd_make_section_anyway_with_flags (htab->elf.dynobj, + ".plt.got", + (bed->dynamic_sec_flags + | SEC_ALLOC + | SEC_CODE + | SEC_LOAD + | SEC_READONLY)); + if (htab->plt_got == NULL + || !bfd_set_section_alignment (htab->elf.dynobj, + htab->plt_got, + plt_got_align)) + return FALSE; + } } return TRUE; @@ -2415,6 +2458,24 @@ 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); + /* 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 + loop at run-time. */ + if (htab->plt_got != NULL + && h->type != STT_GNU_IFUNC + && !h->pointer_equality_needed + && h->plt.refcount > 0 + && h->got.refcount > 0) + { + /* Don't use the regular PLT if there are both GOT and GOTPLT + reloctions. */ + h->plt.offset = (bfd_vma) -1; + + /* Use the GOT PLT. */ + eh->plt_got.refcount = 1; + } + /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it here if it is defined and referenced in a non-shared object. */ if (h->type == STT_GNU_IFUNC @@ -2442,8 +2503,10 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) return FALSE; } else if (htab->elf.dynamic_sections_created - && h->plt.refcount > 0) + && (h->plt.refcount > 0 || eh->plt_got.refcount > 0)) { + bfd_boolean use_plt_got = eh->plt_got.refcount > 0; + /* Make sure this symbol is output as a dynamic symbol. Undefined weak syms won't yet be marked as dynamic. */ if (h->dynindx == -1 @@ -2458,15 +2521,21 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) { asection *s = htab->elf.splt; asection *bnd_s = htab->plt_bnd; + asection *got_s = htab->plt_got; /* If this is the first .plt entry, make room for the special first entry. */ if (s->size == 0) s->size = plt_entry_size; - h->plt.offset = s->size; - if (bnd_s) - eh->plt_bnd.offset = bnd_s->size; + if (use_plt_got) + eh->plt_got.offset = got_s->size; + else + { + h->plt.offset = s->size; + if (bnd_s) + eh->plt_bnd.offset = bnd_s->size; + } /* If this symbol is not defined in a regular file, and we are not generating a shared library, then set the symbol to this @@ -2476,32 +2545,49 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) if (! info->shared && !h->def_regular) { - if (bnd_s) + if (use_plt_got) { - /* We need to make a call to the entry of the second - PLT instead of regular PLT entry. */ - h->root.u.def.section = bnd_s; - h->root.u.def.value = eh->plt_bnd.offset; + /* We need to make a call to the entry of the GOT PLT + instead of regular PLT entry. */ + h->root.u.def.section = got_s; + h->root.u.def.value = eh->plt_got.offset; } else { - h->root.u.def.section = s; - h->root.u.def.value = h->plt.offset; + if (bnd_s) + { + /* We need to make a call to the entry of the second + PLT instead of regular PLT entry. */ + h->root.u.def.section = bnd_s; + h->root.u.def.value = eh->plt_bnd.offset; + } + else + { + h->root.u.def.section = s; + h->root.u.def.value = h->plt.offset; + } } } /* Make room for this entry. */ - s->size += plt_entry_size; - if (bnd_s) - bnd_s->size += sizeof (elf_x86_64_legacy_plt2_entry); + if (use_plt_got) + got_s->size += sizeof (elf_x86_64_legacy_plt2_entry); + else + { + s->size += plt_entry_size; + if (bnd_s) + bnd_s->size += sizeof (elf_x86_64_legacy_plt2_entry); - /* We also need to make an entry in the .got.plt section, which - will be placed in the .got section by the linker script. */ - htab->elf.sgotplt->size += GOT_ENTRY_SIZE; + /* We also need to make an entry in the .got.plt section, + which will be placed in the .got section by the linker + script. */ + htab->elf.sgotplt->size += 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++; + /* 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 { @@ -3120,6 +3206,7 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd, || s == htab->elf.iplt || s == htab->elf.igotplt || s == htab->plt_bnd + || s == htab->plt_got || s == htab->plt_eh_frame || s == htab->sdynbss) { @@ -3885,7 +3972,8 @@ elf_x86_64_relocate_section (bfd *output_bfd, if (h == NULL) break; - if (h->plt.offset == (bfd_vma) -1 + if ((h->plt.offset == (bfd_vma) -1 + && eh->plt_got.offset == (bfd_vma) -1) || htab->elf.splt == NULL) { /* We didn't make a PLT entry for this symbol. This @@ -3894,15 +3982,24 @@ elf_x86_64_relocate_section (bfd *output_bfd, break; } - if (htab->plt_bnd != NULL) + if (h->plt.offset != (bfd_vma) -1) { - resolved_plt = htab->plt_bnd; - plt_offset = eh->plt_bnd.offset; + if (htab->plt_bnd != NULL) + { + resolved_plt = htab->plt_bnd; + plt_offset = eh->plt_bnd.offset; + } + else + { + resolved_plt = htab->elf.splt; + plt_offset = h->plt.offset; + } } else { - resolved_plt = htab->elf.splt; - plt_offset = h->plt.offset; + /* Use the GOT PLT. */ + resolved_plt = htab->plt_got; + plt_offset = eh->plt_got.offset; } relocation = (resolved_plt->output_section->vma @@ -4717,6 +4814,7 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd, 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; htab = elf_x86_64_hash_table (info); if (htab == NULL) @@ -4729,6 +4827,8 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd, ? &elf_x86_64_bnd_arch_bed : get_elf_x86_64_backend_data (output_bfd)); + eh = (struct elf_x86_64_link_hash_entry *) h; + if (h->plt.offset != (bfd_vma) -1) { bfd_vma plt_index; @@ -4796,8 +4896,6 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd, { /* Use the second PLT with BND relocations. */ const bfd_byte *plt_entry, *plt2_entry; - struct elf_x86_64_link_hash_entry *eh - = (struct elf_x86_64_link_hash_entry *) h; if (eh->has_bnd_reloc) { @@ -4914,21 +5012,82 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd, 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) + { + bfd_vma got_offset, plt_offset, plt_got_offset, plt_got_insn_size; + asection *plt, *got; + bfd_boolean got_after_plt; + int32_t got_pcrel_offset; + const bfd_byte *got_plt_entry; + + /* Set the entry in the GOT procedure linkage table. */ + plt = htab->plt_got; + got = htab->elf.sgot; + got_offset = h->got.offset; + + if (got_offset == (bfd_vma) -1 + || h->type == STT_GNU_IFUNC + || plt == NULL + || got == NULL) + abort (); - if (!h->def_regular) + /* Use the second PLT entry template for the GOT PLT since they + are the identical. */ + plt_got_insn_size = elf_x86_64_bnd_arch_bed.plt_got_insn_size; + plt_got_offset = elf_x86_64_bnd_arch_bed.plt_got_offset; + if (eh->has_bnd_reloc) + got_plt_entry = elf_x86_64_bnd_plt2_entry; + else { - /* Mark the symbol as undefined, rather than as defined in - the .plt section. Leave the value if there were any - relocations where pointer equality matters (this is a clue - for the dynamic linker, to make function pointer - comparisons work between an application and shared - library), otherwise set it to zero. If a function is only - called from a binary, there is no need to slow down - shared libraries because of that. */ - sym->st_shndx = SHN_UNDEF; - if (!h->pointer_equality_needed) - sym->st_value = 0; + got_plt_entry = elf_x86_64_legacy_plt2_entry; + + /* Subtract 1 since there is no BND prefix. */ + plt_got_insn_size -= 1; + plt_got_offset -= 1; } + + /* Fill in the entry in the GOT procedure linkage table. */ + plt_offset = eh->plt_got.offset; + memcpy (plt->contents + plt_offset, + got_plt_entry, sizeof (elf_x86_64_legacy_plt2_entry)); + + /* Put offset the PC-relative instruction referring to the GOT + entry, subtracting the size of that instruction. */ + got_pcrel_offset = (got->output_section->vma + + got->output_offset + + got_offset + - plt->output_section->vma + - plt->output_offset + - plt_offset + - plt_got_insn_size); + + /* Check PC-relative offset overflow in GOT PLT entry. */ + got_after_plt = got->output_section->vma > plt->output_section->vma; + if ((got_after_plt && got_pcrel_offset < 0) + || (!got_after_plt && got_pcrel_offset > 0)) + info->callbacks->einfo (_("%F%B: PC-relative offset overflow in GOT PLT entry for `%s'\n"), + output_bfd, h->root.root.string); + + bfd_put_32 (output_bfd, got_pcrel_offset, + plt->contents + plt_offset + plt_got_offset); + } + + if (!h->def_regular + && (h->plt.offset != (bfd_vma) -1 + || eh->plt_got.offset != (bfd_vma) -1)) + { + /* Mark the symbol as undefined, rather than as defined in + the .plt section. Leave the value if there were any + relocations where pointer equality matters (this is a clue + for the dynamic linker, to make function pointer + comparisons work between an application and shared + library), otherwise set it to zero. If a function is only + called from a binary, there is no need to slow down + shared libraries because of that. */ + sym->st_shndx = SHN_UNDEF; + if (!h->pointer_equality_needed) + sym->st_value = 0; } if (h->got.offset != (bfd_vma) -1 diff --git a/ld/ChangeLog b/ld/ChangeLog index f6a4d6f..9ec721f 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,8 @@ +2014-11-25 H.J. Lu <hongjiu.lu@intel.com> + + * emulparams/elf_i386.sh (TINY_READONLY_SECTION): New. + * emulparams/elf_x86_64.sh (TINY_READONLY_SECTION): Add .plt.got. + 2014-11-24 H.J. Lu <hongjiu.lu@intel.com> * configure: Regenerated. diff --git a/ld/emulparams/elf_i386.sh b/ld/emulparams/elf_i386.sh index 93f1992..2ebfaac 100644 --- a/ld/emulparams/elf_i386.sh +++ b/ld/emulparams/elf_i386.sh @@ -13,6 +13,10 @@ GENERATE_PIE_SCRIPT=yes NO_SMALL_DATA=yes SEPARATE_GOTPLT="SIZEOF (.got.plt) >= 12 ? 12 : 0" IREL_IN_PLT= +# Reuse TINY_READONLY_SECTION which is placed right after .plt section. +TINY_READONLY_SECTION=" +.plt.got ${RELOCATING-0} : { *(.plt.got) } +" # Linux modify the default library search path to first include # a 32-bit specific directory. diff --git a/ld/emulparams/elf_x86_64.sh b/ld/emulparams/elf_x86_64.sh index 1e83a74..aa26a1b 100644 --- a/ld/emulparams/elf_x86_64.sh +++ b/ld/emulparams/elf_x86_64.sh @@ -17,7 +17,10 @@ LARGE_BSS_AFTER_BSS= SEPARATE_GOTPLT="SIZEOF (.got.plt) >= 24 ? 24 : 0" IREL_IN_PLT= # Reuse TINY_READONLY_SECTION which is placed right after .plt section. -TINY_READONLY_SECTION=".plt.bnd ${RELOCATING-0} : { *(.plt.bnd) }" +TINY_READONLY_SECTION=" +.plt.got ${RELOCATING-0} : { *(.plt.got) } +.plt.bnd ${RELOCATING-0} : { *(.plt.bnd) } +" if [ "x${host}" = "x${target}" ]; then case " $EMULATION_LIBPATH " in diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog index be12722..a750240 100644 --- a/ld/testsuite/ChangeLog +++ b/ld/testsuite/ChangeLog @@ -1,3 +1,12 @@ +2014-11-25 H.J. Lu <hongjiu.lu@intel.com> + + * ld-i386/i386.exp: Add run-time relocation tests for plt-main. + * ld-i386/plt-main.rd: New file. + * ld-x86-64/plt-main-bnd.dd: Likewise. + * ld-x86-64/plt-main.rd: Likewise. + * ld-x86-64/x86-64.exp: Add run-time relocation tests for + plt-main. + 2014-11-21 H.J. Lu <hongjiu.lu@intel.com> * ld-i386/plt-lib.c: New file. diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp index 4c870b8..304713d 100644 --- a/ld/testsuite/ld-i386/i386.exp +++ b/ld/testsuite/ld-i386/i386.exp @@ -309,6 +309,24 @@ if { [isnative] {{readelf {-Wr} plt-main4.rd}} \ "libplt-main4.a" \ ] \ + [list \ + "Build plt-main" \ + "tmpdir/plt-main1.o tmpdir/plt-main2.o tmpdir/plt-main3.o \ + tmpdir/plt-main4.o tmpdir/libplt-lib.so" \ + "" \ + { plt-main5.c } \ + {{readelf {-Wr} plt-main.rd}} \ + "plt-main" \ + ] \ + [list \ + "Build plt-main with PIE" \ + "tmpdir/plt-main1.o tmpdir/plt-main2.o tmpdir/plt-main3.o \ + tmpdir/plt-main4.o tmpdir/libplt-lib.so -pie" \ + "-fPIC" \ + { plt-main5.c } \ + {{readelf {-Wr} plt-main.rd}} \ + "plt-main" \ + ] \ ] run_ld_link_exec_tests [] [list \ diff --git a/ld/testsuite/ld-i386/plt-main.rd b/ld/testsuite/ld-i386/plt-main.rd new file mode 100644 index 0000000..6d01ff9 --- /dev/null +++ b/ld/testsuite/ld-i386/plt-main.rd @@ -0,0 +1,4 @@ +#failif +#... +[0-9a-f ]+R_386_JUMP_SLOT +0+ +bar +#... diff --git a/ld/testsuite/ld-x86-64/plt-main-bnd.dd b/ld/testsuite/ld-x86-64/plt-main-bnd.dd new file mode 100644 index 0000000..8598e30 --- /dev/null +++ b/ld/testsuite/ld-x86-64/plt-main-bnd.dd @@ -0,0 +1,7 @@ +#... +Disassembly of section .plt.got: + +[a-f0-9]+ <.plt.got>: +[ ]*[a-f0-9]+: f2 ff 25 .. .. 20 00 bnd jmpq \*0x20....\(%rip\) # ...... <_DYNAMIC\+0x...> +[ ]*[a-f0-9]+: 90 nop +#pass diff --git a/ld/testsuite/ld-x86-64/plt-main.rd b/ld/testsuite/ld-x86-64/plt-main.rd new file mode 100644 index 0000000..1effcd4 --- /dev/null +++ b/ld/testsuite/ld-x86-64/plt-main.rd @@ -0,0 +1,4 @@ +#failif +#... +[0-9a-f ]+R_X86_64_JUMP_SLOT +0+ +bar \+ 0 +#... diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp index ab1bfd1..886469b 100644 --- a/ld/testsuite/ld-x86-64/x86-64.exp +++ b/ld/testsuite/ld-x86-64/x86-64.exp @@ -374,6 +374,24 @@ if { [isnative] && [which $CC] != 0 } { {{readelf {-Wr} plt-main4.rd}} \ "libplt-main4.a" \ ] \ + [list \ + "Build plt-main" \ + "tmpdir/plt-main1.o tmpdir/plt-main2.o tmpdir/plt-main3.o \ + tmpdir/plt-main4.o tmpdir/libplt-lib.so" \ + "" \ + { plt-main5.c } \ + {{readelf {-Wr} plt-main.rd}} \ + "plt-main" \ + ] \ + [list \ + "Build plt-main with PIE" \ + "tmpdir/plt-main1.o tmpdir/plt-main2.o tmpdir/plt-main3.o \ + tmpdir/plt-main4.o tmpdir/libplt-lib.so -pie" \ + "-fPIC" \ + { plt-main5.c } \ + {{readelf {-Wr} plt-main.rd}} \ + "plt-main" \ + ] \ ] run_ld_link_exec_tests [] [list \ @@ -397,6 +415,53 @@ if { [isnative] && [which $CC] != 0 } { "-fPIC" \ ] \ ] + + if { [istarget "x86_64-*-linux*"] \ + && ![istarget "x86_64-*-linux*-gnux32"]} { + + run_cc_link_tests [list \ + [list \ + "Build plt-main with -z bndplt" \ + "tmpdir/plt-main1.o tmpdir/plt-main2.o tmpdir/plt-main3.o \ + tmpdir/plt-main4.o tmpdir/libplt-lib.so -z bndplt" \ + "" \ + { plt-main5.c } \ + {{objdump {-drw} plt-main-bnd.dd}} \ + "plt-main-bnd" \ + ] \ + [list \ + "Build plt-main with PIE and -z bndplt" \ + "tmpdir/plt-main1.o tmpdir/plt-main2.o tmpdir/plt-main3.o \ + tmpdir/plt-main4.o tmpdir/libplt-lib.so -z bndplt -pie" \ + "-fPIC" \ + { plt-main5.c } \ + {{objdump {-drw} plt-main-bnd.dd}} \ + "plt-main-pie-bnd" \ + ] \ + ] + + run_ld_link_exec_tests [] [list \ + [list \ + "Run plt-main with -z bndplt" \ + "tmpdir/plt-main1.o tmpdir/plt-main2.o tmpdir/plt-main3.o \ + tmpdir/plt-main4.o tmpdir/libplt-lib.so -z bndplt" \ + "" \ + { plt-main5.c } \ + "plt-main-bnd" \ + "plt-main.out" \ + ] \ + [list \ + "Run plt-main with PIE and -z bndplt" \ + "tmpdir/plt-main1.o tmpdir/plt-main2.o tmpdir/plt-main3.o \ + tmpdir/plt-main4.o tmpdir/libplt-lib.so -z bndplt -pie" \ + "" \ + { plt-main5.c } \ + "plt-main-pie-bnd" \ + "plt-main.out" \ + "-fPIC" \ + ] \ + ] + } } if { ![istarget "x86_64-*-linux*"]} { |