X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=bfd%2Felf64-x86-64.c;h=46f723c5d55c47bca805800403a30f384b288664;hb=0a41a307caca19383b05c8b558c25cf888c1c3f0;hp=4b8303292ab23f3aa2b4146027ca609e8321a4f8;hpb=97dc35c88dd470465a99edeb0b491012a368f2bf;p=deliverable%2Fbinutils-gdb.git diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index 4b8303292a..46f723c5d5 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 +790,21 @@ 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; + + /* 0: symbol isn't __tls_get_addr. + 1: symbol is __tls_get_addr. + 2: symbol is unknown. */ + unsigned int tls_get_addr : 2; + + /* 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; + /* Information about the GOT PLT entry. Filled when there are both GOT and PLT relocations against the same function. */ union gotplt_union plt_got; @@ -822,6 +860,7 @@ 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; @@ -866,6 +905,10 @@ 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. */ @@ -906,6 +949,10 @@ 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->tls_get_addr = 2; + eh->func_pointer_refcount = 0; eh->plt_bnd.offset = (bfd_vma) -1; eh->plt_got.offset = (bfd_vma) -1; eh->tlsdesc_got = (bfd_vma) -1; @@ -976,6 +1023,7 @@ 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->func_pointer_refcount = 0; ret->plt_got.offset = (bfd_vma) -1; *slot = ret; } @@ -1067,11 +1115,22 @@ 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 (); - if (info->executable) + if (bfd_link_executable (info)) { /* Always allow copy relocs for building executables. */ asection *s = bfd_get_linker_section (dynobj, ".rela.bss"); @@ -1121,6 +1180,12 @@ 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) @@ -1173,7 +1238,15 @@ elf_x86_64_copy_indirect_symbol (struct bfd_link_info *info, dir->pointer_equality_needed |= ind->pointer_equality_needed; } else - _bfd_elf_link_hash_copy_indirect (info, dir, ind); + { + if (eind->func_pointer_refcount > 0) + { + edir->func_pointer_refcount += eind->func_pointer_refcount; + eind->func_pointer_refcount = 0; + } + + _bfd_elf_link_hash_copy_indirect (info, dir, ind); + } } static bfd_boolean @@ -1212,22 +1285,8 @@ elf_x86_64_check_tls_transition (bfd *abfd, struct elf_link_hash_entry *h; 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; - } - } + bfd_byte *call; + bfd_boolean indirect_call, tls_get_addr; htab = elf_x86_64_hash_table (info); offset = rel->r_offset; @@ -1242,32 +1301,61 @@ elf_x86_64_check_tls_transition (bfd *abfd, { /* Check transition from GD access model. For 64bit, only .byte 0x66; leaq foo@tlsgd(%rip), %rdi - .word 0x6666; rex64; call __tls_get_addr + .word 0x6666; rex64; call __tls_get_addr@PLT + or + .byte 0x66; leaq foo@tlsgd(%rip), %rdi + .byte 0x66; rex64 + call *__tls_get_addr@GOTPCREL(%rip) + which may be converted to + addr32 call __tls_get_addr can transit to different access model. For 32bit, only leaq foo@tlsgd(%rip), %rdi - .word 0x6666; rex64; call __tls_get_addr - can transit to different access model. For largepic + .word 0x6666; rex64; call __tls_get_addr@PLT + or + leaq foo@tlsgd(%rip), %rdi + .byte 0x66; rex64 + call *__tls_get_addr@GOTPCREL(%rip) + which may be converted to + addr32 call __tls_get_addr + can transit to different access model. For largepic, we also support: + leaq foo@tlsgd(%rip), %rdi + movabsq $__tls_get_addr@pltoff, %rax + addq $r15, %rax + call *%rax + or leaq foo@tlsgd(%rip), %rdi movabsq $__tls_get_addr@pltoff, %rax addq $rbx, %rax - call *%rax. */ + call *%rax */ - static const unsigned char call[] = { 0x66, 0x66, 0x48, 0xe8 }; static const unsigned char leaq[] = { 0x66, 0x48, 0x8d, 0x3d }; if ((offset + 12) > sec->size) return FALSE; - if (memcmp (contents + offset + 4, call, 4) != 0) + call = contents + offset + 4; + if (call[0] != 0x66 + || !((call[1] == 0x48 + && call[2] == 0xff + && call[3] == 0x15) + || (call[1] == 0x48 + && call[2] == 0x67 + && call[3] == 0xe8) + || (call[1] == 0x66 + && call[2] == 0x48 + && call[3] == 0xe8))) { if (!ABI_64_P (abfd) || (offset + 19) > sec->size || offset < 3 - || memcmp (contents + offset - 3, leaq + 1, 3) != 0 - || memcmp (contents + offset + 4, "\x48\xb8", 2) != 0 - || memcmp (contents + offset + 14, "\x48\x01\xd8\xff\xd0", 5) - != 0) + || memcmp (call - 7, leaq + 1, 3) != 0 + || memcmp (call, "\x48\xb8", 2) != 0 + || call[11] != 0x01 + || call[13] != 0xff + || call[14] != 0xd0 + || !((call[10] == 0x48 && call[12] == 0xd8) + || (call[10] == 0x4c && call[12] == 0xf8))) return FALSE; largepic = TRUE; } @@ -1283,18 +1371,29 @@ elf_x86_64_check_tls_transition (bfd *abfd, || memcmp (contents + offset - 3, leaq + 1, 3) != 0) return FALSE; } + indirect_call = call[2] == 0xff; } else { /* Check transition from LD access model. Only leaq foo@tlsld(%rip), %rdi; - call __tls_get_addr + call __tls_get_addr@PLT + or + leaq foo@tlsld(%rip), %rdi; + call *__tls_get_addr@GOTPCREL(%rip) + which may be converted to + addr32 call __tls_get_addr can transit to different access model. For largepic we also support: + leaq foo@tlsld(%rip), %rdi + movabsq $__tls_get_addr@pltoff, %rax + addq $r15, %rax + call *%rax + or leaq foo@tlsld(%rip), %rdi movabsq $__tls_get_addr@pltoff, %rax addq $rbx, %rax - call *%rax. */ + call *%rax */ static const unsigned char lea[] = { 0x48, 0x8d, 0x3d }; @@ -1304,33 +1403,60 @@ elf_x86_64_check_tls_transition (bfd *abfd, if (memcmp (contents + offset - 3, lea, 3) != 0) return FALSE; - if (0xe8 != *(contents + offset + 4)) + call = contents + offset + 4; + if (!(call[0] == 0xe8 + || (call[0] == 0xff && call[1] == 0x15) + || (call[0] == 0x67 && call[1] == 0xe8))) { if (!ABI_64_P (abfd) || (offset + 19) > sec->size - || memcmp (contents + offset + 4, "\x48\xb8", 2) != 0 - || memcmp (contents + offset + 14, "\x48\x01\xd8\xff\xd0", 5) - != 0) + || memcmp (call, "\x48\xb8", 2) != 0 + || call[11] != 0x01 + || call[13] != 0xff + || call[14] != 0xd0 + || !((call[10] == 0x48 && call[12] == 0xd8) + || (call[10] == 0x4c && call[12] == 0xf8))) return FALSE; largepic = TRUE; } + indirect_call = call[0] == 0xff; } r_symndx = htab->r_sym (rel[1].r_info); if (r_symndx < symtab_hdr->sh_info) return FALSE; + tls_get_addr = FALSE; h = sym_hashes[r_symndx - symtab_hdr->sh_info]; - /* Use strncmp to check __tls_get_addr since __tls_get_addr - may be versioned. */ - return (h != NULL - && h->root.root.string != NULL - && (largepic - ? ELF32_R_TYPE (rel[1].r_info) == R_X86_64_PLTOFF64 - : (ELF32_R_TYPE (rel[1].r_info) == R_X86_64_PC32 - || ELF32_R_TYPE (rel[1].r_info) == R_X86_64_PLT32)) - && (strncmp (h->root.root.string, - "__tls_get_addr", 14) == 0)); + if (h != NULL && h->root.root.string != NULL) + { + struct elf_x86_64_link_hash_entry *eh + = (struct elf_x86_64_link_hash_entry *) h; + tls_get_addr = eh->tls_get_addr == 1; + if (eh->tls_get_addr > 1) + { + /* Use strncmp to check __tls_get_addr since + __tls_get_addr may be versioned. */ + if (strncmp (h->root.root.string, "__tls_get_addr", 14) + == 0) + { + eh->tls_get_addr = 1; + tls_get_addr = TRUE; + } + else + eh->tls_get_addr = 0; + } + } + + if (!tls_get_addr) + return FALSE; + else if (largepic) + return ELF32_R_TYPE (rel[1].r_info) == R_X86_64_PLTOFF64; + else if (indirect_call) + return ELF32_R_TYPE (rel[1].r_info) == R_X86_64_GOTPCRELX; + else + return (ELF32_R_TYPE (rel[1].r_info) == R_X86_64_PC32 + || ELF32_R_TYPE (rel[1].r_info) == R_X86_64_PLT32); case R_X86_64_GOTTPOFF: /* Check transition from IE access model: @@ -1393,8 +1519,8 @@ elf_x86_64_check_tls_transition (bfd *abfd, if (offset + 2 <= sec->size) { /* Make sure that it's a call *x@tlsdesc(%rax). */ - static const unsigned char call[] = { 0xff, 0x10 }; - return memcmp (contents + offset, call, 2) == 0; + call = contents + offset; + return call[0] == 0xff && call[1] == 0x10; } return FALSE; @@ -1416,7 +1542,8 @@ 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; @@ -1434,7 +1561,7 @@ elf_x86_64_tls_transition (struct bfd_link_info *info, bfd *abfd, case R_X86_64_GOTPC32_TLSDESC: case R_X86_64_TLSDESC_CALL: case R_X86_64_GOTTPOFF: - if (info->executable) + if (bfd_link_executable (info)) { if (h == NULL) to_type = R_X86_64_TPOFF32; @@ -1442,14 +1569,13 @@ 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; - if (info->executable + if (bfd_link_executable (info) && h != NULL && h->dynindx == -1 && tls_type == GOT_TLS_IE) @@ -1473,7 +1599,7 @@ elf_x86_64_tls_transition (struct bfd_link_info *info, bfd *abfd, break; case R_X86_64_TLSLD: - if (info->executable) + if (bfd_link_executable (info)) to_type = R_X86_64_TPOFF32; break; @@ -1531,7 +1657,470 @@ 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 + { + struct elf_x86_64_link_hash_entry *eh + = (struct elf_x86_64_link_hash_entry *) h; + + /* Convert to "nop call foo". ADDR_PREFIX_OPCODE + is a nop prefix. */ + modrm = 0xe8; + /* To support TLS optimization, always use addr32 prefix for + "call *__tls_get_addr@GOTPCREL(%rip)". */ + if (eh && eh->tls_get_addr == 1) + { + nop = 0x67; + nop_offset = irel->r_offset - 2; + } + else + { + 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 @@ -1548,16 +2137,29 @@ 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 (info->relocatable) + if (bfd_link_relocatable (info)) return TRUE; BFD_ASSERT (is_x86_64_elf (abfd)); 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; @@ -1572,6 +2174,7 @@ 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; @@ -1583,7 +2186,7 @@ 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) @@ -1592,7 +2195,7 @@ 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) @@ -1600,7 +2203,7 @@ 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; @@ -1648,17 +2251,13 @@ 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: @@ -1705,32 +2304,42 @@ 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; } /* It is referenced by a non-shared object. */ h->ref_regular = 1; h->root.non_ir_ref = 1; + + if (h->type == STT_GNU_IFUNC) + elf_tdata (info->output_bfd)->has_gnu_symbols + |= 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: @@ -1738,29 +2347,22 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info, goto create_got; case R_X86_64_TPOFF32: - if (!info->executable && 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; - } + if (!bfd_link_executable (info) && ABI_64_P (abfd)) + 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: - if (!info->executable) + if (!bfd_link_executable (info)) info->flags |= DF_STATIC_TLS; /* Fall through */ 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: @@ -1784,7 +2386,7 @@ 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 { @@ -1802,7 +2404,7 @@ 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); @@ -1836,14 +2438,14 @@ 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; } @@ -1854,13 +2456,15 @@ 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; @@ -1878,6 +2482,7 @@ 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; @@ -1903,24 +2508,20 @@ 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 (info->shared - && (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: @@ -1930,7 +2531,17 @@ 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 && info->executable) + 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 @@ -1943,10 +2554,28 @@ 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) - h->pointer_equality_needed = 1; + 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 + x86-64 and x32. But R_X86_64_32 and R_X86_64_32S + can only be resolved for x32. */ + if ((sec->flags & SEC_READONLY) == 0 + && (r_type == R_X86_64_64 + || (!ABI_64_P (abfd) + && (r_type == R_X86_64_32 + || r_type == R_X86_64_32S)))) + eh->func_pointer_refcount += 1; + } } size_reloc = FALSE; @@ -1972,15 +2601,16 @@ do_size: may need to keep relocations for symbols satisfied by a dynamic library if we manage to avoid copy relocs for the symbol. */ - if ((info->shared + if ((bfd_link_pic (info) && (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 - && !info->shared + && !bfd_link_pic (info) && (sec->flags & SEC_ALLOC) != 0 && h != NULL && (h->root.type == bfd_link_hash_defweak @@ -2002,15 +2632,13 @@ 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. @@ -2022,7 +2650,7 @@ 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) @@ -2042,7 +2670,7 @@ 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; @@ -2061,7 +2689,7 @@ 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 @@ -2070,7 +2698,7 @@ 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: @@ -2100,196 +2728,82 @@ do_size: = 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; - } - - if (r_type == R_X86_64_GOTPCREL - && (h == NULL || h->type != STT_GNU_IFUNC)) - sec->need_convert_mov_to_lea = 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 (info->relocatable) - 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++) - { - unsigned long r_symndx; - unsigned int r_type; - struct elf_link_hash_entry *h = NULL; - - 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; - } - 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; - } - } - - 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; - - switch (r_type) - { - case R_X86_64_TLSLD: - if (htab->tls_ld_got.refcount > 0) - htab->tls_ld_got.refcount -= 1; - break; - - 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; - - case R_X86_64_8: - case R_X86_64_16: - case R_X86_64_32: - case R_X86_64_64: - case R_X86_64_32S: - 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: - if (info->shared - && (h == NULL || h->type != STT_GNU_IFUNC)) - break; - /* Fall thru */ + | 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)) + goto error_return; + } - 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; - } - break; + 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_load = 1; + } - default: - break; + if (elf_section_data (sec)->this_hdr.contents != contents) + { + if (!info->keep_memory) + free (contents); + else + { + /* Cache the section contents for elf_link_input_bfd. */ + elf_section_data (sec)->this_hdr.contents = contents; } } return TRUE; + +error_return: + if (elf_section_data (sec)->this_hdr.contents != contents) + free (contents); + sec->check_relocs_failed = 1; + return FALSE; +} + +/* Return the section that should be marked against GC for a given + 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); +} + +/* Remove undefined weak symbol from the dynamic symbol table if it + is resolved to 0. */ + +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; } /* Adjust a symbol defined by a dynamic object and referenced by a @@ -2405,7 +2919,7 @@ elf_x86_64_adjust_dynamic_symbol (struct bfd_link_info *info, only references to the symbol are via the global offset table. For such cases we need not do anything here; the relocations will be handled correctly by relocate_section. */ - if (!info->executable) + if (!bfd_link_executable (info)) return TRUE; /* If there are no references to this symbol that do not use the @@ -2481,6 +2995,7 @@ 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; @@ -2494,6 +3009,10 @@ 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 @@ -2512,6 +3031,11 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) eh->plt_got.refcount = 1; } + /* Clear the reference count of function pointer relocations if + symbol isn't a normal function. */ + if (h->type != STT_FUNC) + eh->func_pointer_refcount = 0; + /* 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 @@ -2519,6 +3043,7 @@ 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)) @@ -2538,11 +3063,18 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) else return FALSE; } + /* Don't create the PLT entry if there are only function pointer + relocations which can be resolved at run-time. */ else if (htab->elf.dynamic_sections_created - && (h->plt.refcount > 0 || eh->plt_got.refcount > 0)) + && (h->plt.refcount > eh->func_pointer_refcount + || eh->plt_got.refcount > 0)) { bfd_boolean use_plt_got; + /* Clear the reference count of function pointer relocations + if PLT is used. */ + eh->func_pointer_refcount = 0; + if ((info->flags & DF_BIND_NOW) && !h->pointer_equality_needed) { /* Don't use the regular PLT for DF_BIND_NOW. */ @@ -2558,13 +3090,14 @@ 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; } - if (info->shared + if (bfd_link_pic (info) || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h)) { asection *s = htab->elf.splt; @@ -2591,7 +3124,7 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) location in the .plt. This is required to make function pointers compare as equal between the normal executable and the shared library. */ - if (! info->shared + if (! bfd_link_pic (info) && !h->def_regular) { if (use_plt_got) @@ -2632,20 +3165,27 @@ 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; } @@ -2655,7 +3195,7 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) /* If R_X86_64_GOTTPOFF symbol is now local to the binary, make it a R_X86_64_TPOFF32 requiring no GOT entry. */ if (h->got.refcount > 0 - && info->executable + && bfd_link_executable (info) && h->dynindx == -1 && elf_x86_64_hash_entry (h)->tls_type == GOT_TLS_IE) { @@ -2670,7 +3210,8 @@ 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; @@ -2694,17 +3235,19 @@ 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) - && (info->shared + && (bfd_link_pic (info) || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h))) htab->elf.srelgot->size += bed->s->sizeof_rela; if (GOT_TLS_GDESC_P (tls_type)) @@ -2725,7 +3268,7 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) space for pc-relative relocs that have become local due to symbol visibility changes. */ - if (info->shared) + if (bfd_link_pic (info)) { /* Relocs that use pc_count are those that appear on a call insn, or certain REL relocs that can generated via assembly. @@ -2749,16 +3292,16 @@ 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)) @@ -2766,7 +3309,7 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) } /* For PIE, discard space for pc-relative relocs against symbols which turn out to need copy relocs. */ - else if (info->executable + else if (bfd_link_executable (info) && (h->needs_copy || eh->needs_copy) && h->def_dynamic && !h->def_regular) @@ -2787,9 +3330,13 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) { /* For the non-shared case, discard space for relocs against symbols which turn out to need copy relocs or are not - dynamic. */ + dynamic. Keep dynamic relocations for run-time function + pointer initialization. */ - if (!h->non_got_ref + 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 @@ -2800,6 +3347,7 @@ 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; @@ -2810,6 +3358,7 @@ elf_x86_64_allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf) } eh->dyn_relocs = NULL; + eh->func_pointer_refcount = 0; keep: ; } @@ -2872,7 +3421,7 @@ elf_x86_64_readonly_dynrelocs (struct elf_link_hash_entry *h, info->flags |= DF_TEXTREL; - if ((info->warn_shared_textrel && info->shared) + if ((info->warn_shared_textrel && bfd_link_pic (info)) || info->error_textrel) info->callbacks->einfo (_("%P: %B: warning: relocation against `%s' in readonly section `%A'\n"), p->sec->owner, h->root.root.string, @@ -2885,25 +3434,19 @@ 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)) @@ -2911,7 +3454,7 @@ 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; @@ -2924,11 +3467,9 @@ 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) @@ -2943,187 +3484,58 @@ 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; - enum { - none, local, global - } convert_mov_to_lea; - 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; - tsec = NULL; - convert_mov_to_lea = none; - - /* 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; - - /* Silence older GCC warning. */ - h = NULL; - - 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) - { - 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; - convert_mov_to_lea = local; - } - } + 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; - convert_mov_to_lea = global; - } } - if (convert_mov_to_lea == none) + /* STT_GNU_IFUNC must keep GOTPCREL relocations. */ + if (h != NULL && h->type == STT_GNU_IFUNC) 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; + converted = FALSE; + if (!elf_x86_64_convert_load_reloc (abfd, sec, contents, irel, h, + &converted, link_info)) + goto error_return; - /* Don't convert if R_X86_64_PC32 relocation overflows. */ - if (tsec->output_section == sec->output_section) - { - if ((toff - roff + 0x80000000) > 0xffffffff) - continue; - } - else + 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 (convert_mov_to_lea == local) - { - if (local_got_refcounts != NULL - && local_got_refcounts[r_symndx] > 0) - local_got_refcounts[r_symndx] -= 1; - } - else - { - if (h->got.refcount > 0) - h->got.refcount -= 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 { @@ -3134,7 +3546,7 @@ 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; @@ -3174,19 +3586,6 @@ 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 (info->executable) - { - 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) @@ -3206,7 +3605,7 @@ 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 *) @@ -3230,7 +3629,7 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd, && (info->flags & DF_TEXTREL) == 0) { info->flags |= DF_TEXTREL; - if ((info->warn_shared_textrel && info->shared) + if ((info->warn_shared_textrel && bfd_link_pic (info)) || info->error_textrel) info->callbacks->einfo (_("%P: %B: warning: relocation in readonly section `%A'\n"), p->sec->owner, p->sec); @@ -3271,7 +3670,7 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd, if (GOT_TLS_GD_P (*local_tls_type)) s->size += GOT_ENTRY_SIZE; } - if (info->shared + if (bfd_link_pic (info) || GOT_TLS_GD_ANY_P (*local_tls_type) || *local_tls_type == GOT_TLS_IE) { @@ -3466,7 +3865,7 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd, #define add_dynamic_entry(TAG, VAL) \ _bfd_elf_add_dynamic_entry (info, TAG, VAL) - if (info->executable) + if (bfd_link_executable (info)) { if (!add_dynamic_entry (DT_DEBUG, 0)) return FALSE; @@ -3509,6 +3908,14 @@ elf_x86_64_size_dynamic_sections (bfd *output_bfd, if ((info->flags & DF_TEXTREL) != 0) { + if (htab->readonly_dynrelocs_against_ifunc) + { + info->callbacks->einfo + (_("%P%X: read-only segment has dynamic IFUNC relocations; recompile with -fPIC\n")); + bfd_set_error (bfd_error_bad_value); + return FALSE; + } + if (!add_dynamic_entry (DT_TEXTREL, 0)) return FALSE; } @@ -3574,7 +3981,7 @@ elf_x86_64_set_tls_module_base (struct bfd_link_info *info) struct elf_x86_64_link_hash_table *htab; struct bfd_link_hash_entry *base; - if (!info->executable) + if (!bfd_link_executable (info)) return; htab = elf_x86_64_hash_table (info); @@ -3656,11 +4063,16 @@ 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; @@ -3671,9 +4083,9 @@ 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; @@ -3689,11 +4101,16 @@ 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) { @@ -3725,7 +4142,7 @@ elf_x86_64_relocate_section (bfd *output_bfd, st_size = sym->st_size; /* Relocate against local STT_GNU_IFUNC symbol. */ - if (!info->relocatable + if (!bfd_link_relocatable (info) && ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC) { h = elf_x86_64_get_local_sym_hash (htab, input_bfd, @@ -3751,11 +4168,29 @@ 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--; - if (info->relocatable) - continue; + continue; + } + + if (bfd_link_relocatable (info)) + { + if (wrel != rel) + *wrel = *rel; + continue; + } if (rel->r_addend == 0 && !ABI_64_P (output_bfd)) { @@ -3792,7 +4227,7 @@ elf_x86_64_relocate_section (bfd *output_bfd, sections because such sections are not SEC_ALLOC and thus ld.so will not process them. */ if ((input_section->flags & SEC_DEBUGGING) != 0) - break; + continue; abort (); } else if (h->plt.offset == (bfd_vma) -1) @@ -3832,13 +4267,12 @@ 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; case R_X86_64_32S: - if (info->shared) + if (bfd_link_pic (info)) abort (); goto do_relocation; @@ -3857,15 +4291,14 @@ 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; } /* Generate dynamic relcoation only when there is a non-GOT reference in a shared object. */ - if (info->shared && h->non_got_ref) + if (bfd_link_pic (info) && h->non_got_ref) { Elf_Internal_Rela outrel; asection *sreloc; @@ -3885,7 +4318,7 @@ elf_x86_64_relocate_section (bfd *output_bfd, if (h->dynindx == -1 || h->forced_local - || info->executable) + || bfd_link_executable (info)) { /* This symbol is resolved locally. */ outrel.r_info = htab->r_info (0, R_X86_64_IRELATIVE); @@ -3918,6 +4351,8 @@ 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; @@ -3977,6 +4412,11 @@ 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) @@ -3986,6 +4426,8 @@ 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: @@ -4015,8 +4457,8 @@ elf_x86_64_relocate_section (bfd *output_bfd, dyn = htab->elf.dynamic_sections_created; - if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, info->shared, h) - || (info->shared + if (! WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, bfd_link_pic (info), h) + || (bfd_link_pic (info) && SYMBOL_REFERENCES_LOCAL (info, h)) || (ELF_ST_VISIBILITY (h->other) && h->root.type == bfd_link_hash_undefweak)) @@ -4063,7 +4505,7 @@ elf_x86_64_relocate_section (bfd *output_bfd, bfd_put_64 (output_bfd, relocation, base_got->contents + off); - if (info->shared) + if (bfd_link_pic (info)) { asection *s; Elf_Internal_Rela outrel; @@ -4091,7 +4533,10 @@ 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; @@ -4105,7 +4550,7 @@ elf_x86_64_relocate_section (bfd *output_bfd, symbol for shared library since it may not be local when used as function address or with copy relocation. We also need to make sure that a symbol is referenced locally. */ - if (info->shared && h) + if (bfd_link_pic (info) && h) { if (!h->def_regular) { @@ -4133,7 +4578,7 @@ elf_x86_64_relocate_section (bfd *output_bfd, bfd_set_error (bfd_error_bad_value); return FALSE; } - else if (!info->executable + else if (!bfd_link_executable (info) && !SYMBOL_REFERENCES_LOCAL (info, h) && (h->type == STT_FUNC || h->type == STT_OBJECT) @@ -4252,13 +4697,16 @@ 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 (info->shared - && (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 - && !(info->executable - && 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 @@ -4272,7 +4720,7 @@ elf_x86_64_relocate_section (bfd *output_bfd, defined locally or for a branch. */ fail = !h->def_regular && !branch; } - else if (!(info->executable + else if (!(bfd_link_pie (info) && (h->needs_copy || eh->needs_copy))) { /* Symbol doesn't need copy reloc and isn't referenced @@ -4283,39 +4731,8 @@ 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. */ @@ -4333,29 +4750,35 @@ 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. */ - if ((info->shared - && !(info->executable + when building executable. Copy dynamic function pointer + relocations. Don't generate dynamic relocations against + resolved undefined weak symbols in PIE. */ + if ((bfd_link_pic (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) || ! SYMBOL_CALLS_LOCAL (info, h))) || (ELIMINATE_COPY_RELOCS - && !info->shared + && !bfd_link_pic (info) && h != NULL && h->dynindx != -1 - && !h->non_got_ref - && ((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; @@ -4387,8 +4810,8 @@ direct: else if (h != NULL && h->dynindx != -1 && (IS_X86_64_PCREL_TYPE (r_type) - || ! info->shared - || ! 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); @@ -4396,8 +4819,12 @@ 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); @@ -4427,16 +4854,16 @@ 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; } @@ -4510,7 +4937,7 @@ 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) @@ -4522,39 +4949,53 @@ direct: if (ELF32_R_TYPE (rel->r_info) == R_X86_64_TLSGD) { /* GD->LE transition. For 64bit, change - .byte 0x66; leaq foo@tlsgd(%rip), %rdi - .word 0x6666; rex64; call __tls_get_addr + .byte 0x66; leaq foo@tlsgd(%rip), %rdi + .word 0x6666; rex64; call __tls_get_addr@PLT + or + .byte 0x66; leaq foo@tlsgd(%rip), %rdi + .byte 0x66; rex64 + call *__tls_get_addr@GOTPCREL(%rip) + which may be converted to + addr32 call __tls_get_addr into: - movq %fs:0, %rax - leaq foo@tpoff(%rax), %rax + movq %fs:0, %rax + leaq foo@tpoff(%rax), %rax For 32bit, change - leaq foo@tlsgd(%rip), %rdi - .word 0x6666; rex64; call __tls_get_addr + leaq foo@tlsgd(%rip), %rdi + .word 0x6666; rex64; call __tls_get_addr@PLT + or + leaq foo@tlsgd(%rip), %rdi + .byte 0x66; rex64 + call *__tls_get_addr@GOTPCREL(%rip) + which may be converted to + addr32 call __tls_get_addr into: - movl %fs:0, %eax - leaq foo@tpoff(%rax), %rax + movl %fs:0, %eax + leaq foo@tpoff(%rax), %rax For largepic, change: - leaq foo@tlsgd(%rip), %rdi - movabsq $__tls_get_addr@pltoff, %rax - addq %rbx, %rax - call *%rax + leaq foo@tlsgd(%rip), %rdi + movabsq $__tls_get_addr@pltoff, %rax + addq %r15, %rax + call *%rax into: - movq %fs:0, %rax - leaq foo@tpoff(%rax), %rax - nopw 0x0(%rax,%rax,1) */ + movq %fs:0, %rax + leaq foo@tpoff(%rax), %rax + nopw 0x0(%rax,%rax,1) */ int largepic = 0; - if (ABI_64_P (output_bfd) - && contents[roff + 5] == (bfd_byte) '\xb8') + if (ABI_64_P (output_bfd)) { - memcpy (contents + roff - 3, - "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80" - "\0\0\0\0\x66\x0f\x1f\x44\0", 22); - largepic = 1; + if (contents[roff + 5] == 0xb8) + { + memcpy (contents + roff - 3, + "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80" + "\0\0\0\0\x66\x0f\x1f\x44\0", 22); + largepic = 1; + } + else + memcpy (contents + roff - 4, + "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0", + 16); } - else if (ABI_64_P (output_bfd)) - memcpy (contents + roff - 4, - "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0", - 16); else memcpy (contents + roff - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0", @@ -4562,8 +5003,10 @@ direct: bfd_put_32 (output_bfd, elf_x86_64_tpoff (info, relocation), contents + roff + 8 + largepic); - /* Skip R_X86_64_PC32/R_X86_64_PLT32/R_X86_64_PLTOFF64. */ + /* Skip R_X86_64_PC32, R_X86_64_PLT32, + R_X86_64_GOTPCRELX and R_X86_64_PLTOFF64. */ rel++; + wrel++; continue; } else if (ELF32_R_TYPE (rel->r_info) == R_X86_64_GOTPC32_TLSDESC) @@ -4797,39 +5240,53 @@ direct: if (ELF32_R_TYPE (rel->r_info) == R_X86_64_TLSGD) { /* GD->IE transition. For 64bit, change - .byte 0x66; leaq foo@tlsgd(%rip), %rdi - .word 0x6666; rex64; call __tls_get_addr@plt + .byte 0x66; leaq foo@tlsgd(%rip), %rdi + .word 0x6666; rex64; call __tls_get_addr@PLT + or + .byte 0x66; leaq foo@tlsgd(%rip), %rdi + .byte 0x66; rex64 + call *__tls_get_addr@GOTPCREL(%rip + which may be converted to + addr32 call __tls_get_addr into: - movq %fs:0, %rax - addq foo@gottpoff(%rip), %rax + movq %fs:0, %rax + addq foo@gottpoff(%rip), %rax For 32bit, change - leaq foo@tlsgd(%rip), %rdi - .word 0x6666; rex64; call __tls_get_addr@plt + leaq foo@tlsgd(%rip), %rdi + .word 0x6666; rex64; call __tls_get_addr@PLT + or + leaq foo@tlsgd(%rip), %rdi + .byte 0x66; rex64; + call *__tls_get_addr@GOTPCREL(%rip) + which may be converted to + addr32 call __tls_get_addr into: - movl %fs:0, %eax - addq foo@gottpoff(%rip), %rax + movl %fs:0, %eax + addq foo@gottpoff(%rip), %rax For largepic, change: - leaq foo@tlsgd(%rip), %rdi - movabsq $__tls_get_addr@pltoff, %rax - addq %rbx, %rax - call *%rax + leaq foo@tlsgd(%rip), %rdi + movabsq $__tls_get_addr@pltoff, %rax + addq %r15, %rax + call *%rax into: - movq %fs:0, %rax - addq foo@gottpoff(%rax), %rax - nopw 0x0(%rax,%rax,1) */ + movq %fs:0, %rax + addq foo@gottpoff(%rax), %rax + nopw 0x0(%rax,%rax,1) */ int largepic = 0; - if (ABI_64_P (output_bfd) - && contents[roff + 5] == (bfd_byte) '\xb8') + if (ABI_64_P (output_bfd)) { - memcpy (contents + roff - 3, - "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05" - "\0\0\0\0\x66\x0f\x1f\x44\0", 22); - largepic = 1; + if (contents[roff + 5] == 0xb8) + { + memcpy (contents + roff - 3, + "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05" + "\0\0\0\0\x66\x0f\x1f\x44\0", 22); + largepic = 1; + } + else + memcpy (contents + roff - 4, + "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0", + 16); } - else if (ABI_64_P (output_bfd)) - memcpy (contents + roff - 4, - "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0", - 16); else memcpy (contents + roff - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0", @@ -4846,6 +5303,7 @@ 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) @@ -4895,41 +5353,67 @@ 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) { /* LD->LE transition: - leaq foo@tlsld(%rip), %rdi; call __tls_get_addr. + leaq foo@tlsld(%rip), %rdi + call __tls_get_addr@PLT + For 64bit, we change it into: + .word 0x6666; .byte 0x66; movq %fs:0, %rax + For 32bit, we change it into: + nopl 0x0(%rax); movl %fs:0, %eax + Or + leaq foo@tlsld(%rip), %rdi; + call *__tls_get_addr@GOTPCREL(%rip) + which may be converted to + addr32 call __tls_get_addr For 64bit, we change it into: - .word 0x6666; .byte 0x66; movq %fs:0, %rax. + .word 0x6666; .word 0x6666; movq %fs:0, %rax For 32bit, we change it into: - nopl 0x0(%rax); movl %fs:0, %eax. + nopw 0x0(%rax); movl %fs:0, %eax For largepic, change: - leaq foo@tlsgd(%rip), %rdi - movabsq $__tls_get_addr@pltoff, %rax - addq %rbx, %rax - call *%rax - into: - data32 data32 data32 nopw %cs:0x0(%rax,%rax,1) - movq %fs:0, %eax */ + leaq foo@tlsgd(%rip), %rdi + movabsq $__tls_get_addr@pltoff, %rax + addq %rbx, %rax + call *%rax + into + data16 data16 data16 nopw %cs:0x0(%rax,%rax,1) + movq %fs:0, %eax */ BFD_ASSERT (r_type == R_X86_64_TPOFF32); - if (ABI_64_P (output_bfd) - && contents[rel->r_offset + 5] == (bfd_byte) '\xb8') - memcpy (contents + rel->r_offset - 3, - "\x66\x66\x66\x66\x2e\x0f\x1f\x84\0\0\0\0\0" - "\x64\x48\x8b\x04\x25\0\0\0", 22); - else if (ABI_64_P (output_bfd)) - memcpy (contents + rel->r_offset - 3, - "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0", 12); + if (ABI_64_P (output_bfd)) + { + if (contents[rel->r_offset + 5] == 0xb8) + memcpy (contents + rel->r_offset - 3, + "\x66\x66\x66\x66\x2e\x0f\x1f\x84\0\0\0\0\0" + "\x64\x48\x8b\x04\x25\0\0\0", 22); + else if (contents[rel->r_offset + 4] == 0xff + || contents[rel->r_offset + 4] == 0x67) + memcpy (contents + rel->r_offset - 3, + "\x66\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0", + 13); + else + memcpy (contents + rel->r_offset - 3, + "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0", 12); + } else - memcpy (contents + rel->r_offset - 3, - "\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. */ + { + if (contents[rel->r_offset + 4] == 0xff) + memcpy (contents + rel->r_offset - 3, + "\x66\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0", + 13); + else + memcpy (contents + rel->r_offset - 3, + "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0", 12); + } + /* Skip R_X86_64_PC32, R_X86_64_PLT32, R_X86_64_GOTPCRELX + and R_X86_64_PLTOFF64. */ rel++; + wrel++; continue; } @@ -4965,7 +5449,8 @@ direct: break; case R_X86_64_DTPOFF32: - if (!info->executable|| (input_section->flags & SEC_CODE) == 0) + if (!bfd_link_executable (info) + || (input_section->flags & SEC_CODE) == 0) relocation -= elf_x86_64_dtpoff_base (info); else relocation = elf_x86_64_tpoff (info, relocation); @@ -4973,7 +5458,7 @@ direct: case R_X86_64_TPOFF32: case R_X86_64_TPOFF64: - BFD_ASSERT (info->executable); + BFD_ASSERT (bfd_link_executable (info)); relocation = elf_x86_64_tpoff (info, relocation); break; @@ -5029,13 +5514,9 @@ check_relocation_error: } if (r == bfd_reloc_overflow) - { - if (! ((*info->callbacks->reloc_overflow) - (info, (h ? &h->root : NULL), name, howto->name, - (bfd_vma) 0, input_bfd, input_section, - rel->r_offset))) - return FALSE; - } + (*info->callbacks->reloc_overflow) + (info, (h ? &h->root : NULL), name, howto->name, + (bfd_vma) 0, input_bfd, input_section, rel->r_offset); else { (*_bfd_error_handler) @@ -5045,6 +5526,29 @@ 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; @@ -5057,12 +5561,13 @@ 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) @@ -5077,6 +5582,13 @@ 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; @@ -5106,7 +5618,8 @@ 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 - && !((h->forced_local || info->executable) + && !local_undefweak + && !((h->forced_local || bfd_link_executable (info)) && h->def_regular && h->type == STT_GNU_IFUNC)) || plt == NULL @@ -5206,60 +5719,67 @@ 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 - || ((info->executable - || ELF_ST_VISIBILITY (h->other) != STV_DEFAULT) - && h->def_regular - && h->type == STT_GNU_IFUNC)) - { - /* If an STT_GNU_IFUNC symbol is locally defined, generate - R_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) { @@ -5321,7 +5841,8 @@ 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)) { @@ -5338,9 +5859,12 @@ 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; @@ -5361,7 +5885,7 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd, if (h->def_regular && h->type == STT_GNU_IFUNC) { - if (info->shared) + if (bfd_link_pic (info)) { /* Generate R_X86_64_GLOB_DAT. */ goto do_glob_dat; @@ -5384,7 +5908,7 @@ elf_x86_64_finish_dynamic_symbol (bfd *output_bfd, return TRUE; } } - else if (info->shared + else if (bfd_link_pic (info) && SYMBOL_REFERENCES_LOCAL (info, h)) { if (!h->def_regular) @@ -5446,14 +5970,54 @@ 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. */ static enum elf_reloc_type_class -elf_x86_64_reloc_type_class (const struct bfd_link_info *info ATTRIBUTE_UNUSED, +elf_x86_64_reloc_type_class (const struct bfd_link_info *info, const asection *rel_sec ATTRIBUTE_UNUSED, const Elf_Internal_Rela *rela) { + 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); + + 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)) { case R_X86_64_RELATIVE: @@ -5698,6 +6262,12 @@ 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; } @@ -5774,19 +6344,20 @@ 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 @@ -5844,7 +6415,7 @@ 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, @@ -5873,12 +6444,6 @@ elf_x86_64_add_symbol_hook (bfd *abfd, return TRUE; } - if ((ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC - || 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 = TRUE; - return TRUE; } @@ -6051,6 +6616,7 @@ 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 @@ -6068,7 +6634,6 @@ 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 @@ -6106,6 +6671,10 @@ 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" @@ -6155,16 +6724,33 @@ 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. */ @@ -6196,6 +6782,8 @@ 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. */ @@ -6216,11 +6804,11 @@ static const bfd_byte elf_x86_64_nacl_plt0_entry[NACL_PLT_ENTRY_SIZE] = 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, /* nopw 0x0(%rax,%rax,1) */ /* 32 bytes of nop to pad out to the standard size. */ - 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, /* excess data32 prefixes */ + 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, /* excess data16 prefixes */ 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, /* nopw %cs:0x0(%rax,%rax,1) */ - 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, /* excess data32 prefixes */ + 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, /* excess data16 prefixes */ 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, /* nopw %cs:0x0(%rax,%rax,1) */ - 0x66, /* excess data32 prefix */ + 0x66, /* excess data16 prefix */ 0x90 /* nop */ }; @@ -6232,7 +6820,7 @@ static const bfd_byte elf_x86_64_nacl_plt_entry[NACL_PLT_ENTRY_SIZE] = 0x41, 0xff, 0xe3, /* jmpq *%r11 */ /* 15-byte nop sequence to pad out to the next 32-byte boundary. */ - 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, /* excess data32 prefixes */ + 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, /* excess data16 prefixes */ 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, /* nopw %cs:0x0(%rax,%rax,1) */ /* Lazy GOT entries point here (32-byte aligned). */ @@ -6242,7 +6830,7 @@ static const bfd_byte elf_x86_64_nacl_plt_entry[NACL_PLT_ENTRY_SIZE] = 0, 0, 0, 0, /* replaced with offset to start of .plt0. */ /* 22 bytes of nop to pad out to the standard size. */ - 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, /* excess data32 prefixes */ + 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, /* excess data16 prefixes */ 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, /* nopw %cs:0x0(%rax,%rax,1) */ 0x0f, 0x1f, 0x80, 0, 0, 0, 0, /* nopl 0x0(%rax) */ };