/* X86-64 specific support for ELF Copyright (C) 2000-2023 Free Software Foundation, Inc. Contributed by Jan Hubicka . This file is part of BFD, the Binary File Descriptor library. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ #include "elfxx-x86.h" #include "dwarf2.h" #include "libiberty.h" #include "sframe.h" #include "opcode/i386.h" #ifdef CORE_HEADER #include #include CORE_HEADER #endif /* In case we're on a 32-bit machine, construct a 64-bit "-1" value. */ #define MINUS_ONE (~ (bfd_vma) 0) /* Since both 32-bit and 64-bit x86-64 encode relocation type in the identical manner, we use ELF32_R_TYPE instead of ELF64_R_TYPE to get relocation type. We also use ELF_ST_TYPE instead of ELF64_ST_TYPE since they are the same. */ /* The relocation "howto" table. Order of fields: type, rightshift, size, bitsize, pc_relative, bitpos, complain_on_overflow, special_function, name, partial_inplace, src_mask, dst_mask, pcrel_offset. */ static reloc_howto_type x86_64_elf_howto_table[] = { HOWTO(R_X86_64_NONE, 0, 0, 0, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_NONE", false, 0, 0x00000000, false), HOWTO(R_X86_64_64, 0, 8, 64, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_64", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_PC32, 0, 4, 32, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_PC32", false, 0, 0xffffffff, true), HOWTO(R_X86_64_GOT32, 0, 4, 32, false, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_GOT32", false, 0, 0xffffffff, false), HOWTO(R_X86_64_PLT32, 0, 4, 32, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_PLT32", false, 0, 0xffffffff, true), HOWTO(R_X86_64_COPY, 0, 4, 32, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_X86_64_COPY", false, 0, 0xffffffff, false), HOWTO(R_X86_64_GLOB_DAT, 0, 8, 64, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_GLOB_DAT", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_JUMP_SLOT, 0, 8, 64, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_JUMP_SLOT", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_RELATIVE, 0, 8, 64, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_RELATIVE", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_GOTPCREL, 0, 4, 32, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_GOTPCREL", false, 0, 0xffffffff, true), HOWTO(R_X86_64_32, 0, 4, 32, false, 0, complain_overflow_unsigned, bfd_elf_generic_reloc, "R_X86_64_32", false, 0, 0xffffffff, false), HOWTO(R_X86_64_32S, 0, 4, 32, false, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_32S", false, 0, 0xffffffff, false), HOWTO(R_X86_64_16, 0, 2, 16, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_X86_64_16", false, 0, 0xffff, false), HOWTO(R_X86_64_PC16, 0, 2, 16, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_X86_64_PC16", false, 0, 0xffff, true), HOWTO(R_X86_64_8, 0, 1, 8, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_X86_64_8", false, 0, 0xff, false), HOWTO(R_X86_64_PC8, 0, 1, 8, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_PC8", false, 0, 0xff, true), HOWTO(R_X86_64_DTPMOD64, 0, 8, 64, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_DTPMOD64", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_DTPOFF64, 0, 8, 64, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_DTPOFF64", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_TPOFF64, 0, 8, 64, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_TPOFF64", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_TLSGD, 0, 4, 32, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_TLSGD", false, 0, 0xffffffff, true), HOWTO(R_X86_64_TLSLD, 0, 4, 32, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_TLSLD", false, 0, 0xffffffff, true), HOWTO(R_X86_64_DTPOFF32, 0, 4, 32, false, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_DTPOFF32", false, 0, 0xffffffff, false), HOWTO(R_X86_64_GOTTPOFF, 0, 4, 32, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_GOTTPOFF", false, 0, 0xffffffff, true), HOWTO(R_X86_64_TPOFF32, 0, 4, 32, false, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_TPOFF32", false, 0, 0xffffffff, false), HOWTO(R_X86_64_PC64, 0, 8, 64, true, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_PC64", false, 0, MINUS_ONE, true), HOWTO(R_X86_64_GOTOFF64, 0, 8, 64, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_GOTOFF64", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_GOTPC32, 0, 4, 32, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_GOTPC32", false, 0, 0xffffffff, true), HOWTO(R_X86_64_GOT64, 0, 8, 64, false, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_GOT64", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_GOTPCREL64, 0, 8, 64, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_GOTPCREL64", false, 0, MINUS_ONE, true), HOWTO(R_X86_64_GOTPC64, 0, 8, 64, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_GOTPC64", false, 0, MINUS_ONE, true), HOWTO(R_X86_64_GOTPLT64, 0, 8, 64, false, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_GOTPLT64", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_PLTOFF64, 0, 8, 64, false, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_PLTOFF64", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_SIZE32, 0, 4, 32, false, 0, complain_overflow_unsigned, bfd_elf_generic_reloc, "R_X86_64_SIZE32", false, 0, 0xffffffff, false), HOWTO(R_X86_64_SIZE64, 0, 8, 64, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_SIZE64", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_GOTPC32_TLSDESC, 0, 4, 32, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_X86_64_GOTPC32_TLSDESC", false, 0, 0xffffffff, true), HOWTO(R_X86_64_TLSDESC_CALL, 0, 0, 0, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_TLSDESC_CALL", false, 0, 0, false), HOWTO(R_X86_64_TLSDESC, 0, 8, 64, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_TLSDESC", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_IRELATIVE, 0, 8, 64, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_IRELATIVE", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_RELATIVE64, 0, 8, 64, false, 0, complain_overflow_dont, bfd_elf_generic_reloc, "R_X86_64_RELATIVE64", false, 0, MINUS_ONE, false), HOWTO(R_X86_64_PC32_BND, 0, 4, 32, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_PC32_BND", false, 0, 0xffffffff, true), HOWTO(R_X86_64_PLT32_BND, 0, 4, 32, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_PLT32_BND", false, 0, 0xffffffff, true), HOWTO(R_X86_64_GOTPCRELX, 0, 4, 32, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_GOTPCRELX", false, 0, 0xffffffff, true), HOWTO(R_X86_64_REX_GOTPCRELX, 0, 4, 32, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_REX_GOTPCRELX", false, 0, 0xffffffff, true), HOWTO(R_X86_64_CODE_4_GOTPCRELX, 0, 4, 32, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_CODE_4_GOTPCRELX", false, 0, 0xffffffff, true), HOWTO(R_X86_64_CODE_4_GOTTPOFF, 0, 4, 32, true, 0, complain_overflow_signed, bfd_elf_generic_reloc, "R_X86_64_CODE_4_GOTTPOFF", false, 0, 0xffffffff, true), HOWTO(R_X86_64_CODE_4_GOTPC32_TLSDESC, 0, 4, 32, true, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_X86_64_CODE_4_GOTPC32_TLSDESC", false, 0, 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_CODE_4_GOTPC32_TLSDESC + 1) #define R_X86_64_vt_offset (R_X86_64_GNU_VTINHERIT - R_X86_64_standard) /* GNU extension to record C++ vtable hierarchy. */ HOWTO (R_X86_64_GNU_VTINHERIT, 0, 8, 0, false, 0, complain_overflow_dont, NULL, "R_X86_64_GNU_VTINHERIT", false, 0, 0, false), /* GNU extension to record C++ vtable member usage. */ HOWTO (R_X86_64_GNU_VTENTRY, 0, 8, 0, false, 0, complain_overflow_dont, _bfd_elf_rel_vtable_reloc_fn, "R_X86_64_GNU_VTENTRY", false, 0, 0, false), /* Use complain_overflow_bitfield on R_X86_64_32 for x32. */ HOWTO(R_X86_64_32, 0, 4, 32, false, 0, complain_overflow_bitfield, bfd_elf_generic_reloc, "R_X86_64_32", false, 0, 0xffffffff, false) }; /* Map BFD relocs to the x86_64 elf relocs. */ struct elf_reloc_map { bfd_reloc_code_real_type bfd_reloc_val; unsigned char elf_reloc_val; }; static const struct elf_reloc_map x86_64_reloc_map[] = { { BFD_RELOC_NONE, R_X86_64_NONE, }, { BFD_RELOC_64, R_X86_64_64, }, { BFD_RELOC_32_PCREL, R_X86_64_PC32, }, { BFD_RELOC_X86_64_GOT32, R_X86_64_GOT32,}, { BFD_RELOC_X86_64_PLT32, R_X86_64_PLT32,}, { BFD_RELOC_X86_64_COPY, R_X86_64_COPY, }, { BFD_RELOC_X86_64_GLOB_DAT, R_X86_64_GLOB_DAT, }, { BFD_RELOC_X86_64_JUMP_SLOT, R_X86_64_JUMP_SLOT, }, { BFD_RELOC_X86_64_RELATIVE, R_X86_64_RELATIVE, }, { BFD_RELOC_X86_64_GOTPCREL, R_X86_64_GOTPCREL, }, { BFD_RELOC_32, R_X86_64_32, }, { BFD_RELOC_X86_64_32S, R_X86_64_32S, }, { BFD_RELOC_16, R_X86_64_16, }, { BFD_RELOC_16_PCREL, R_X86_64_PC16, }, { BFD_RELOC_8, R_X86_64_8, }, { BFD_RELOC_8_PCREL, R_X86_64_PC8, }, { BFD_RELOC_X86_64_DTPMOD64, R_X86_64_DTPMOD64, }, { BFD_RELOC_X86_64_DTPOFF64, R_X86_64_DTPOFF64, }, { BFD_RELOC_X86_64_TPOFF64, R_X86_64_TPOFF64, }, { BFD_RELOC_X86_64_TLSGD, R_X86_64_TLSGD, }, { BFD_RELOC_X86_64_TLSLD, R_X86_64_TLSLD, }, { BFD_RELOC_X86_64_DTPOFF32, R_X86_64_DTPOFF32, }, { BFD_RELOC_X86_64_GOTTPOFF, R_X86_64_GOTTPOFF, }, { BFD_RELOC_X86_64_TPOFF32, R_X86_64_TPOFF32, }, { BFD_RELOC_64_PCREL, R_X86_64_PC64, }, { BFD_RELOC_X86_64_GOTOFF64, R_X86_64_GOTOFF64, }, { BFD_RELOC_X86_64_GOTPC32, R_X86_64_GOTPC32, }, { BFD_RELOC_X86_64_GOT64, R_X86_64_GOT64, }, { BFD_RELOC_X86_64_GOTPCREL64,R_X86_64_GOTPCREL64, }, { BFD_RELOC_X86_64_GOTPC64, R_X86_64_GOTPC64, }, { BFD_RELOC_X86_64_GOTPLT64, R_X86_64_GOTPLT64, }, { BFD_RELOC_X86_64_PLTOFF64, R_X86_64_PLTOFF64, }, { BFD_RELOC_SIZE32, R_X86_64_SIZE32, }, { BFD_RELOC_SIZE64, R_X86_64_SIZE64, }, { BFD_RELOC_X86_64_GOTPC32_TLSDESC, R_X86_64_GOTPC32_TLSDESC, }, { 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_GOTPCRELX, R_X86_64_GOTPCRELX, }, { BFD_RELOC_X86_64_REX_GOTPCRELX, R_X86_64_REX_GOTPCRELX, }, { BFD_RELOC_X86_64_CODE_4_GOTPCRELX, R_X86_64_CODE_4_GOTPCRELX, }, { BFD_RELOC_X86_64_CODE_4_GOTTPOFF, R_X86_64_CODE_4_GOTTPOFF, }, { BFD_RELOC_X86_64_CODE_4_GOTPC32_TLSDESC, R_X86_64_CODE_4_GOTPC32_TLSDESC, }, { BFD_RELOC_VTABLE_INHERIT, R_X86_64_GNU_VTINHERIT, }, { BFD_RELOC_VTABLE_ENTRY, R_X86_64_GNU_VTENTRY, }, }; static reloc_howto_type * elf_x86_64_rtype_to_howto (bfd *abfd, unsigned r_type) { unsigned i; if (r_type == (unsigned int) R_X86_64_32) { if (ABI_64_P (abfd)) i = r_type; else i = ARRAY_SIZE (x86_64_elf_howto_table) - 1; } else if (r_type < (unsigned int) R_X86_64_GNU_VTINHERIT || r_type >= (unsigned int) R_X86_64_max) { if (r_type >= (unsigned int) R_X86_64_standard) { /* xgettext:c-format */ _bfd_error_handler (_("%pB: unsupported relocation type %#x"), abfd, r_type); bfd_set_error (bfd_error_bad_value); return NULL; } i = r_type; } else i = r_type - (unsigned int) R_X86_64_vt_offset; BFD_ASSERT (x86_64_elf_howto_table[i].type == r_type); return &x86_64_elf_howto_table[i]; } /* Given a BFD reloc type, return a HOWTO structure. */ static reloc_howto_type * elf_x86_64_reloc_type_lookup (bfd *abfd, bfd_reloc_code_real_type code) { unsigned int i; for (i = 0; i < sizeof (x86_64_reloc_map) / sizeof (struct elf_reloc_map); i++) { if (x86_64_reloc_map[i].bfd_reloc_val == code) return elf_x86_64_rtype_to_howto (abfd, x86_64_reloc_map[i].elf_reloc_val); } return NULL; } static reloc_howto_type * elf_x86_64_reloc_name_lookup (bfd *abfd, const char *r_name) { unsigned int i; if (!ABI_64_P (abfd) && strcasecmp (r_name, "R_X86_64_32") == 0) { /* Get x32 R_X86_64_32. */ reloc_howto_type *reloc = &x86_64_elf_howto_table[ARRAY_SIZE (x86_64_elf_howto_table) - 1]; BFD_ASSERT (reloc->type == (unsigned int) R_X86_64_32); return reloc; } for (i = 0; i < ARRAY_SIZE (x86_64_elf_howto_table); i++) if (x86_64_elf_howto_table[i].name != NULL && strcasecmp (x86_64_elf_howto_table[i].name, r_name) == 0) return &x86_64_elf_howto_table[i]; return NULL; } /* Given an x86_64 ELF reloc type, fill in an arelent structure. */ static bool elf_x86_64_info_to_howto (bfd *abfd, arelent *cache_ptr, Elf_Internal_Rela *dst) { unsigned r_type; r_type = ELF32_R_TYPE (dst->r_info); cache_ptr->howto = elf_x86_64_rtype_to_howto (abfd, r_type); if (cache_ptr->howto == NULL) return false; BFD_ASSERT (r_type == cache_ptr->howto->type || cache_ptr->howto->type == R_X86_64_NONE); return true; } /* Support for core dump NOTE sections. */ static bool elf_x86_64_grok_prstatus (bfd *abfd, Elf_Internal_Note *note) { int offset; size_t size; switch (note->descsz) { default: return false; case 296: /* sizeof(istruct elf_prstatus) on Linux/x32 */ /* pr_cursig */ elf_tdata (abfd)->core->signal = bfd_get_16 (abfd, note->descdata + 12); /* pr_pid */ elf_tdata (abfd)->core->lwpid = bfd_get_32 (abfd, note->descdata + 24); /* pr_reg */ offset = 72; size = 216; break; case 336: /* sizeof(istruct elf_prstatus) on Linux/x86_64 */ /* pr_cursig */ elf_tdata (abfd)->core->signal = bfd_get_16 (abfd, note->descdata + 12); /* pr_pid */ elf_tdata (abfd)->core->lwpid = bfd_get_32 (abfd, note->descdata + 32); /* pr_reg */ offset = 112; size = 216; break; } /* Make a ".reg/999" section. */ return _bfd_elfcore_make_pseudosection (abfd, ".reg", size, note->descpos + offset); } static bool elf_x86_64_grok_psinfo (bfd *abfd, Elf_Internal_Note *note) { switch (note->descsz) { default: return false; case 124: /* sizeof (struct elf_external_linux_prpsinfo32_ugid16). */ elf_tdata (abfd)->core->pid = bfd_get_32 (abfd, note->descdata + 12); elf_tdata (abfd)->core->program = _bfd_elfcore_strndup (abfd, note->descdata + 28, 16); elf_tdata (abfd)->core->command = _bfd_elfcore_strndup (abfd, note->descdata + 44, 80); break; case 128: /* sizeof (struct elf_external_linux_prpsinfo32_ugid32). */ elf_tdata (abfd)->core->pid = bfd_get_32 (abfd, note->descdata + 12); elf_tdata (abfd)->core->program = _bfd_elfcore_strndup (abfd, note->descdata + 32, 16); elf_tdata (abfd)->core->command = _bfd_elfcore_strndup (abfd, note->descdata + 48, 80); break; case 136: /* sizeof (struct elf_prpsinfo) on Linux/x86_64. */ elf_tdata (abfd)->core->pid = bfd_get_32 (abfd, note->descdata + 24); elf_tdata (abfd)->core->program = _bfd_elfcore_strndup (abfd, note->descdata + 40, 16); elf_tdata (abfd)->core->command = _bfd_elfcore_strndup (abfd, note->descdata + 56, 80); } /* Note that for some reason, a spurious space is tacked onto the end of the args in some (at least one anyway) implementations, so strip it off if it exists. */ { char *command = elf_tdata (abfd)->core->command; int n = strlen (command); if (0 < n && command[n - 1] == ' ') command[n - 1] = '\0'; } return true; } #ifdef CORE_HEADER # if GCC_VERSION >= 8000 # pragma GCC diagnostic push # pragma GCC diagnostic ignored "-Wstringop-truncation" # endif static char * elf_x86_64_write_core_note (bfd *abfd, char *buf, int *bufsiz, int note_type, ...) { const struct elf_backend_data *bed = get_elf_backend_data (abfd); va_list ap; const char *fname, *psargs; long pid; int cursig; const void *gregs; switch (note_type) { default: return NULL; case NT_PRPSINFO: va_start (ap, note_type); fname = va_arg (ap, const char *); psargs = va_arg (ap, const char *); va_end (ap); if (bed->s->elfclass == ELFCLASS32) { prpsinfo32_t data; memset (&data, 0, sizeof (data)); strncpy (data.pr_fname, fname, sizeof (data.pr_fname)); strncpy (data.pr_psargs, psargs, sizeof (data.pr_psargs)); return elfcore_write_note (abfd, buf, bufsiz, "CORE", note_type, &data, sizeof (data)); } else { prpsinfo64_t data; memset (&data, 0, sizeof (data)); strncpy (data.pr_fname, fname, sizeof (data.pr_fname)); strncpy (data.pr_psargs, psargs, sizeof (data.pr_psargs)); return elfcore_write_note (abfd, buf, bufsiz, "CORE", note_type, &data, sizeof (data)); } /* NOTREACHED */ case NT_PRSTATUS: va_start (ap, note_type); pid = va_arg (ap, long); cursig = va_arg (ap, int); gregs = va_arg (ap, const void *); va_end (ap); if (bed->s->elfclass == ELFCLASS32) { if (bed->elf_machine_code == EM_X86_64) { prstatusx32_t prstat; memset (&prstat, 0, sizeof (prstat)); prstat.pr_pid = pid; prstat.pr_cursig = cursig; memcpy (&prstat.pr_reg, gregs, sizeof (prstat.pr_reg)); return elfcore_write_note (abfd, buf, bufsiz, "CORE", note_type, &prstat, sizeof (prstat)); } else { prstatus32_t prstat; memset (&prstat, 0, sizeof (prstat)); prstat.pr_pid = pid; prstat.pr_cursig = cursig; memcpy (&prstat.pr_reg, gregs, sizeof (prstat.pr_reg)); return elfcore_write_note (abfd, buf, bufsiz, "CORE", note_type, &prstat, sizeof (prstat)); } } else { prstatus64_t prstat; memset (&prstat, 0, sizeof (prstat)); prstat.pr_pid = pid; prstat.pr_cursig = cursig; memcpy (&prstat.pr_reg, gregs, sizeof (prstat.pr_reg)); return elfcore_write_note (abfd, buf, bufsiz, "CORE", note_type, &prstat, sizeof (prstat)); } } /* NOTREACHED */ } # if GCC_VERSION >= 8000 # pragma GCC diagnostic pop # endif #endif /* Functions for the x86-64 ELF linker. */ /* The size in bytes of an entry in the global offset table. */ #define GOT_ENTRY_SIZE 8 /* The size in bytes of an entry in the lazy procedure linkage table. */ #define LAZY_PLT_ENTRY_SIZE 16 /* The size in bytes of an entry in the non-lazy procedure linkage table. */ #define NON_LAZY_PLT_ENTRY_SIZE 8 /* The first entry in a lazy procedure linkage table looks like this. See the SVR4 ABI i386 supplement and the x86-64 ABI to see how this works. */ static const bfd_byte elf_x86_64_lazy_plt0_entry[LAZY_PLT_ENTRY_SIZE] = { 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */ 0xff, 0x25, 16, 0, 0, 0, /* jmpq *GOT+16(%rip) */ 0x0f, 0x1f, 0x40, 0x00 /* nopl 0(%rax) */ }; /* Subsequent entries in a lazy procedure linkage table look like this. */ static const bfd_byte elf_x86_64_lazy_plt_entry[LAZY_PLT_ENTRY_SIZE] = { 0xff, 0x25, /* jmpq *name@GOTPC(%rip) */ 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */ 0x68, /* pushq immediate */ 0, 0, 0, 0, /* replaced with index into relocation table. */ 0xe9, /* jmp relative */ 0, 0, 0, 0 /* replaced with offset to start of .plt0. */ }; /* The first entry in a lazy procedure linkage table with BND prefix like this. */ static const bfd_byte elf_x86_64_lazy_bnd_plt0_entry[LAZY_PLT_ENTRY_SIZE] = { 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */ 0xf2, 0xff, 0x25, 16, 0, 0, 0, /* bnd jmpq *GOT+16(%rip) */ 0x0f, 0x1f, 0 /* nopl (%rax) */ }; /* Subsequent entries for branches with BND prefx in a lazy procedure linkage table look like this. */ static const bfd_byte elf_x86_64_lazy_bnd_plt_entry[LAZY_PLT_ENTRY_SIZE] = { 0x68, 0, 0, 0, 0, /* pushq immediate */ 0xf2, 0xe9, 0, 0, 0, 0, /* bnd jmpq relative */ 0x0f, 0x1f, 0x44, 0, 0 /* nopl 0(%rax,%rax,1) */ }; /* The first entry in the IBT-enabled lazy procedure linkage table is the the same as the lazy PLT with BND prefix so that bound registers are preserved when control is passed to dynamic linker. Subsequent entries for a IBT-enabled lazy procedure linkage table look like this. */ static const bfd_byte elf_x86_64_lazy_ibt_plt_entry[LAZY_PLT_ENTRY_SIZE] = { 0xf3, 0x0f, 0x1e, 0xfa, /* endbr64 */ 0x68, 0, 0, 0, 0, /* pushq immediate */ 0xf2, 0xe9, 0, 0, 0, 0, /* bnd jmpq relative */ 0x90 /* nop */ }; /* The first entry in the x32 IBT-enabled lazy procedure linkage table is the same as the normal lazy PLT. Subsequent entries for an x32 IBT-enabled lazy procedure linkage table look like this. */ static const bfd_byte elf_x32_lazy_ibt_plt_entry[LAZY_PLT_ENTRY_SIZE] = { 0xf3, 0x0f, 0x1e, 0xfa, /* endbr64 */ 0x68, 0, 0, 0, 0, /* pushq immediate */ 0xe9, 0, 0, 0, 0, /* jmpq relative */ 0x66, 0x90 /* xchg %ax,%ax */ }; /* Entries in the non-lazey procedure linkage table look like this. */ static const bfd_byte elf_x86_64_non_lazy_plt_entry[NON_LAZY_PLT_ENTRY_SIZE] = { 0xff, 0x25, /* jmpq *name@GOTPC(%rip) */ 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */ 0x66, 0x90 /* xchg %ax,%ax */ }; /* Entries for branches with BND prefix in the non-lazey procedure linkage table look like this. */ static const bfd_byte elf_x86_64_non_lazy_bnd_plt_entry[NON_LAZY_PLT_ENTRY_SIZE] = { 0xf2, 0xff, 0x25, /* bnd jmpq *name@GOTPC(%rip) */ 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */ 0x90 /* nop */ }; /* Entries for branches with IBT-enabled in the non-lazey procedure linkage table look like this. They have the same size as the lazy PLT entry. */ static const bfd_byte elf_x86_64_non_lazy_ibt_plt_entry[LAZY_PLT_ENTRY_SIZE] = { 0xf3, 0x0f, 0x1e, 0xfa, /* endbr64 */ 0xf2, 0xff, 0x25, /* bnd jmpq *name@GOTPC(%rip) */ 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */ 0x0f, 0x1f, 0x44, 0x00, 0x00 /* nopl 0x0(%rax,%rax,1) */ }; /* Entries for branches with IBT-enabled in the x32 non-lazey procedure linkage table look like this. They have the same size as the lazy PLT entry. */ static const bfd_byte elf_x32_non_lazy_ibt_plt_entry[LAZY_PLT_ENTRY_SIZE] = { 0xf3, 0x0f, 0x1e, 0xfa, /* endbr64 */ 0xff, 0x25, /* jmpq *name@GOTPC(%rip) */ 0, 0, 0, 0, /* replaced with offset to this symbol in .got. */ 0x66, 0x0f, 0x1f, 0x44, 0x00, 0x00 /* nopw 0x0(%rax,%rax,1) */ }; /* The TLSDESC entry in a lazy procedure linkage table. */ static const bfd_byte elf_x86_64_tlsdesc_plt_entry[LAZY_PLT_ENTRY_SIZE] = { 0xf3, 0x0f, 0x1e, 0xfa, /* endbr64 */ 0xff, 0x35, 8, 0, 0, 0, /* pushq GOT+8(%rip) */ 0xff, 0x25, 16, 0, 0, 0 /* jmpq *GOT+TDG(%rip) */ }; /* .eh_frame covering the lazy .plt section. */ static const bfd_byte elf_x86_64_eh_frame_lazy_plt[] = { PLT_CIE_LENGTH, 0, 0, 0, /* CIE length */ 0, 0, 0, 0, /* CIE ID */ 1, /* CIE version */ 'z', 'R', 0, /* Augmentation string */ 1, /* Code alignment factor */ 0x78, /* Data alignment factor */ 16, /* Return address column */ 1, /* Augmentation size */ DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding */ DW_CFA_def_cfa, 7, 8, /* DW_CFA_def_cfa: r7 (rsp) ofs 8 */ DW_CFA_offset + 16, 1, /* DW_CFA_offset: r16 (rip) at cfa-8 */ DW_CFA_nop, DW_CFA_nop, PLT_FDE_LENGTH, 0, 0, 0, /* FDE length */ PLT_CIE_LENGTH + 8, 0, 0, 0, /* CIE pointer */ 0, 0, 0, 0, /* R_X86_64_PC32 .plt goes here */ 0, 0, 0, 0, /* .plt size goes here */ 0, /* Augmentation size */ DW_CFA_def_cfa_offset, 16, /* DW_CFA_def_cfa_offset: 16 */ DW_CFA_advance_loc + 6, /* DW_CFA_advance_loc: 6 to __PLT__+6 */ DW_CFA_def_cfa_offset, 24, /* DW_CFA_def_cfa_offset: 24 */ DW_CFA_advance_loc + 10, /* DW_CFA_advance_loc: 10 to __PLT__+16 */ DW_CFA_def_cfa_expression, /* DW_CFA_def_cfa_expression */ 11, /* Block length */ DW_OP_breg7, 8, /* DW_OP_breg7 (rsp): 8 */ DW_OP_breg16, 0, /* DW_OP_breg16 (rip): 0 */ DW_OP_lit15, DW_OP_and, DW_OP_lit11, DW_OP_ge, DW_OP_lit3, DW_OP_shl, DW_OP_plus, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop }; /* .eh_frame covering the lazy BND .plt section. */ static const bfd_byte elf_x86_64_eh_frame_lazy_bnd_plt[] = { PLT_CIE_LENGTH, 0, 0, 0, /* CIE length */ 0, 0, 0, 0, /* CIE ID */ 1, /* CIE version */ 'z', 'R', 0, /* Augmentation string */ 1, /* Code alignment factor */ 0x78, /* Data alignment factor */ 16, /* Return address column */ 1, /* Augmentation size */ DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding */ DW_CFA_def_cfa, 7, 8, /* DW_CFA_def_cfa: r7 (rsp) ofs 8 */ DW_CFA_offset + 16, 1, /* DW_CFA_offset: r16 (rip) at cfa-8 */ DW_CFA_nop, DW_CFA_nop, PLT_FDE_LENGTH, 0, 0, 0, /* FDE length */ PLT_CIE_LENGTH + 8, 0, 0, 0, /* CIE pointer */ 0, 0, 0, 0, /* R_X86_64_PC32 .plt goes here */ 0, 0, 0, 0, /* .plt size goes here */ 0, /* Augmentation size */ DW_CFA_def_cfa_offset, 16, /* DW_CFA_def_cfa_offset: 16 */ DW_CFA_advance_loc + 6, /* DW_CFA_advance_loc: 6 to __PLT__+6 */ DW_CFA_def_cfa_offset, 24, /* DW_CFA_def_cfa_offset: 24 */ DW_CFA_advance_loc + 10, /* DW_CFA_advance_loc: 10 to __PLT__+16 */ DW_CFA_def_cfa_expression, /* DW_CFA_def_cfa_expression */ 11, /* Block length */ DW_OP_breg7, 8, /* DW_OP_breg7 (rsp): 8 */ DW_OP_breg16, 0, /* DW_OP_breg16 (rip): 0 */ DW_OP_lit15, DW_OP_and, DW_OP_lit5, DW_OP_ge, DW_OP_lit3, DW_OP_shl, DW_OP_plus, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop }; /* .eh_frame covering the lazy .plt section with IBT-enabled. */ static const bfd_byte elf_x86_64_eh_frame_lazy_ibt_plt[] = { PLT_CIE_LENGTH, 0, 0, 0, /* CIE length */ 0, 0, 0, 0, /* CIE ID */ 1, /* CIE version */ 'z', 'R', 0, /* Augmentation string */ 1, /* Code alignment factor */ 0x78, /* Data alignment factor */ 16, /* Return address column */ 1, /* Augmentation size */ DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding */ DW_CFA_def_cfa, 7, 8, /* DW_CFA_def_cfa: r7 (rsp) ofs 8 */ DW_CFA_offset + 16, 1, /* DW_CFA_offset: r16 (rip) at cfa-8 */ DW_CFA_nop, DW_CFA_nop, PLT_FDE_LENGTH, 0, 0, 0, /* FDE length */ PLT_CIE_LENGTH + 8, 0, 0, 0, /* CIE pointer */ 0, 0, 0, 0, /* R_X86_64_PC32 .plt goes here */ 0, 0, 0, 0, /* .plt size goes here */ 0, /* Augmentation size */ DW_CFA_def_cfa_offset, 16, /* DW_CFA_def_cfa_offset: 16 */ DW_CFA_advance_loc + 6, /* DW_CFA_advance_loc: 6 to __PLT__+6 */ DW_CFA_def_cfa_offset, 24, /* DW_CFA_def_cfa_offset: 24 */ DW_CFA_advance_loc + 10, /* DW_CFA_advance_loc: 10 to __PLT__+16 */ DW_CFA_def_cfa_expression, /* DW_CFA_def_cfa_expression */ 11, /* Block length */ DW_OP_breg7, 8, /* DW_OP_breg7 (rsp): 8 */ DW_OP_breg16, 0, /* DW_OP_breg16 (rip): 0 */ DW_OP_lit15, DW_OP_and, DW_OP_lit10, DW_OP_ge, DW_OP_lit3, DW_OP_shl, DW_OP_plus, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop }; /* .eh_frame covering the x32 lazy .plt section with IBT-enabled. */ static const bfd_byte elf_x32_eh_frame_lazy_ibt_plt[] = { PLT_CIE_LENGTH, 0, 0, 0, /* CIE length */ 0, 0, 0, 0, /* CIE ID */ 1, /* CIE version */ 'z', 'R', 0, /* Augmentation string */ 1, /* Code alignment factor */ 0x78, /* Data alignment factor */ 16, /* Return address column */ 1, /* Augmentation size */ DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding */ DW_CFA_def_cfa, 7, 8, /* DW_CFA_def_cfa: r7 (rsp) ofs 8 */ DW_CFA_offset + 16, 1, /* DW_CFA_offset: r16 (rip) at cfa-8 */ DW_CFA_nop, DW_CFA_nop, PLT_FDE_LENGTH, 0, 0, 0, /* FDE length */ PLT_CIE_LENGTH + 8, 0, 0, 0, /* CIE pointer */ 0, 0, 0, 0, /* R_X86_64_PC32 .plt goes here */ 0, 0, 0, 0, /* .plt size goes here */ 0, /* Augmentation size */ DW_CFA_def_cfa_offset, 16, /* DW_CFA_def_cfa_offset: 16 */ DW_CFA_advance_loc + 6, /* DW_CFA_advance_loc: 6 to __PLT__+6 */ DW_CFA_def_cfa_offset, 24, /* DW_CFA_def_cfa_offset: 24 */ DW_CFA_advance_loc + 10, /* DW_CFA_advance_loc: 10 to __PLT__+16 */ DW_CFA_def_cfa_expression, /* DW_CFA_def_cfa_expression */ 11, /* Block length */ DW_OP_breg7, 8, /* DW_OP_breg7 (rsp): 8 */ DW_OP_breg16, 0, /* DW_OP_breg16 (rip): 0 */ DW_OP_lit15, DW_OP_and, DW_OP_lit9, DW_OP_ge, DW_OP_lit3, DW_OP_shl, DW_OP_plus, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop }; /* .eh_frame covering the non-lazy .plt section. */ static const bfd_byte elf_x86_64_eh_frame_non_lazy_plt[] = { #define PLT_GOT_FDE_LENGTH 20 PLT_CIE_LENGTH, 0, 0, 0, /* CIE length */ 0, 0, 0, 0, /* CIE ID */ 1, /* CIE version */ 'z', 'R', 0, /* Augmentation string */ 1, /* Code alignment factor */ 0x78, /* Data alignment factor */ 16, /* Return address column */ 1, /* Augmentation size */ DW_EH_PE_pcrel | DW_EH_PE_sdata4, /* FDE encoding */ DW_CFA_def_cfa, 7, 8, /* DW_CFA_def_cfa: r7 (rsp) ofs 8 */ DW_CFA_offset + 16, 1, /* DW_CFA_offset: r16 (rip) at cfa-8 */ DW_CFA_nop, DW_CFA_nop, PLT_GOT_FDE_LENGTH, 0, 0, 0, /* FDE length */ PLT_CIE_LENGTH + 8, 0, 0, 0, /* CIE pointer */ 0, 0, 0, 0, /* the start of non-lazy .plt goes here */ 0, 0, 0, 0, /* non-lazy .plt size goes here */ 0, /* Augmentation size */ DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop, DW_CFA_nop }; static const sframe_frame_row_entry elf_x86_64_sframe_null_fre = { 0, {16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* 12 bytes. */ SFRAME_V1_FRE_INFO (SFRAME_BASE_REG_SP, 1, SFRAME_FRE_OFFSET_1B) /* FRE info. */ }; /* .sframe FRE covering the .plt section entry. */ static const sframe_frame_row_entry elf_x86_64_sframe_plt0_fre1 = { 0, /* SFrame FRE start address. */ {16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* 12 bytes. */ SFRAME_V1_FRE_INFO (SFRAME_BASE_REG_SP, 1, SFRAME_FRE_OFFSET_1B) /* FRE info. */ }; /* .sframe FRE covering the .plt section entry. */ static const sframe_frame_row_entry elf_x86_64_sframe_plt0_fre2 = { 6, /* SFrame FRE start address. */ {24, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* 12 bytes. */ SFRAME_V1_FRE_INFO (SFRAME_BASE_REG_SP, 1, SFRAME_FRE_OFFSET_1B) /* FRE info. */ }; /* .sframe FRE covering the .plt section entry. */ static const sframe_frame_row_entry elf_x86_64_sframe_pltn_fre1 = { 0, /* SFrame FRE start address. */ {8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* 12 bytes. */ SFRAME_V1_FRE_INFO (SFRAME_BASE_REG_SP, 1, SFRAME_FRE_OFFSET_1B) /* FRE info. */ }; /* .sframe FRE covering the .plt section entry. */ static const sframe_frame_row_entry elf_x86_64_sframe_pltn_fre2 = { 11, /* SFrame FRE start address. */ {16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* 12 bytes. */ SFRAME_V1_FRE_INFO (SFRAME_BASE_REG_SP, 1, SFRAME_FRE_OFFSET_1B) /* FRE info. */ }; /* .sframe FRE covering the second .plt section entry. */ static const sframe_frame_row_entry elf_x86_64_sframe_sec_pltn_fre1 = { 0, /* SFrame FRE start address. */ {8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, /* 12 bytes. */ SFRAME_V1_FRE_INFO (SFRAME_BASE_REG_SP, 1, SFRAME_FRE_OFFSET_1B) /* FRE info. */ }; /* SFrame helper object for non-lazy PLT. Also used for IBT enabled PLT. */ static const struct elf_x86_sframe_plt elf_x86_64_sframe_non_lazy_plt = { LAZY_PLT_ENTRY_SIZE, 2, /* Number of FREs for PLT0. */ /* Array of SFrame FREs for plt0. */ { &elf_x86_64_sframe_plt0_fre1, &elf_x86_64_sframe_plt0_fre2 }, LAZY_PLT_ENTRY_SIZE, 1, /* Number of FREs for PLTn. */ /* Array of SFrame FREs for plt. */ { &elf_x86_64_sframe_sec_pltn_fre1, &elf_x86_64_sframe_null_fre }, 0, 0, /* There is no second PLT necessary. */ { &elf_x86_64_sframe_null_fre } }; /* SFrame helper object for lazy PLT. Also used for IBT enabled PLT. */ static const struct elf_x86_sframe_plt elf_x86_64_sframe_plt = { LAZY_PLT_ENTRY_SIZE, 2, /* Number of FREs for PLT0. */ /* Array of SFrame FREs for plt0. */ { &elf_x86_64_sframe_plt0_fre1, &elf_x86_64_sframe_plt0_fre2 }, LAZY_PLT_ENTRY_SIZE, 2, /* Number of FREs for PLTn. */ /* Array of SFrame FREs for plt. */ { &elf_x86_64_sframe_pltn_fre1, &elf_x86_64_sframe_pltn_fre2 }, NON_LAZY_PLT_ENTRY_SIZE, 1, /* Number of FREs for PLTn for second PLT. */ /* FREs for second plt (stack trace info for .plt.got is identical). Used when IBT or non-lazy PLT is in effect. */ { &elf_x86_64_sframe_sec_pltn_fre1 } }; /* These are the standard parameters. */ static const struct elf_x86_lazy_plt_layout elf_x86_64_lazy_plt = { elf_x86_64_lazy_plt0_entry, /* plt0_entry */ LAZY_PLT_ENTRY_SIZE, /* plt0_entry_size */ elf_x86_64_lazy_plt_entry, /* plt_entry */ LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */ elf_x86_64_tlsdesc_plt_entry, /* plt_tlsdesc_entry */ LAZY_PLT_ENTRY_SIZE, /* plt_tlsdesc_entry_size */ 6, /* plt_tlsdesc_got1_offset */ 12, /* plt_tlsdesc_got2_offset */ 10, /* plt_tlsdesc_got1_insn_end */ 16, /* plt_tlsdesc_got2_insn_end */ 2, /* plt0_got1_offset */ 8, /* plt0_got2_offset */ 12, /* plt0_got2_insn_end */ 2, /* plt_got_offset */ 7, /* plt_reloc_offset */ 12, /* plt_plt_offset */ 6, /* plt_got_insn_size */ LAZY_PLT_ENTRY_SIZE, /* plt_plt_insn_end */ 6, /* plt_lazy_offset */ elf_x86_64_lazy_plt0_entry, /* pic_plt0_entry */ elf_x86_64_lazy_plt_entry, /* pic_plt_entry */ elf_x86_64_eh_frame_lazy_plt, /* eh_frame_plt */ sizeof (elf_x86_64_eh_frame_lazy_plt) /* eh_frame_plt_size */ }; static const struct elf_x86_non_lazy_plt_layout elf_x86_64_non_lazy_plt = { elf_x86_64_non_lazy_plt_entry, /* plt_entry */ elf_x86_64_non_lazy_plt_entry, /* pic_plt_entry */ NON_LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */ 2, /* plt_got_offset */ 6, /* plt_got_insn_size */ elf_x86_64_eh_frame_non_lazy_plt, /* eh_frame_plt */ sizeof (elf_x86_64_eh_frame_non_lazy_plt) /* eh_frame_plt_size */ }; static const struct elf_x86_lazy_plt_layout elf_x86_64_lazy_bnd_plt = { elf_x86_64_lazy_bnd_plt0_entry, /* plt0_entry */ LAZY_PLT_ENTRY_SIZE, /* plt0_entry_size */ elf_x86_64_lazy_bnd_plt_entry, /* plt_entry */ LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */ elf_x86_64_tlsdesc_plt_entry, /* plt_tlsdesc_entry */ LAZY_PLT_ENTRY_SIZE, /* plt_tlsdesc_entry_size */ 6, /* plt_tlsdesc_got1_offset */ 12, /* plt_tlsdesc_got2_offset */ 10, /* plt_tlsdesc_got1_insn_end */ 16, /* plt_tlsdesc_got2_insn_end */ 2, /* plt0_got1_offset */ 1+8, /* plt0_got2_offset */ 1+12, /* plt0_got2_insn_end */ 1+2, /* plt_got_offset */ 1, /* plt_reloc_offset */ 7, /* plt_plt_offset */ 1+6, /* plt_got_insn_size */ 11, /* plt_plt_insn_end */ 0, /* plt_lazy_offset */ elf_x86_64_lazy_bnd_plt0_entry, /* pic_plt0_entry */ elf_x86_64_lazy_bnd_plt_entry, /* pic_plt_entry */ elf_x86_64_eh_frame_lazy_bnd_plt, /* eh_frame_plt */ sizeof (elf_x86_64_eh_frame_lazy_bnd_plt) /* eh_frame_plt_size */ }; static const struct elf_x86_non_lazy_plt_layout elf_x86_64_non_lazy_bnd_plt = { elf_x86_64_non_lazy_bnd_plt_entry, /* plt_entry */ elf_x86_64_non_lazy_bnd_plt_entry, /* pic_plt_entry */ NON_LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */ 1+2, /* plt_got_offset */ 1+6, /* plt_got_insn_size */ elf_x86_64_eh_frame_non_lazy_plt, /* eh_frame_plt */ sizeof (elf_x86_64_eh_frame_non_lazy_plt) /* eh_frame_plt_size */ }; static const struct elf_x86_lazy_plt_layout elf_x86_64_lazy_ibt_plt = { elf_x86_64_lazy_bnd_plt0_entry, /* plt0_entry */ LAZY_PLT_ENTRY_SIZE, /* plt0_entry_size */ elf_x86_64_lazy_ibt_plt_entry, /* plt_entry */ LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */ elf_x86_64_tlsdesc_plt_entry, /* plt_tlsdesc_entry */ LAZY_PLT_ENTRY_SIZE, /* plt_tlsdesc_entry_size */ 6, /* plt_tlsdesc_got1_offset */ 12, /* plt_tlsdesc_got2_offset */ 10, /* plt_tlsdesc_got1_insn_end */ 16, /* plt_tlsdesc_got2_insn_end */ 2, /* plt0_got1_offset */ 1+8, /* plt0_got2_offset */ 1+12, /* plt0_got2_insn_end */ 4+1+2, /* plt_got_offset */ 4+1, /* plt_reloc_offset */ 4+1+6, /* plt_plt_offset */ 4+1+6, /* plt_got_insn_size */ 4+1+5+5, /* plt_plt_insn_end */ 0, /* plt_lazy_offset */ elf_x86_64_lazy_bnd_plt0_entry, /* pic_plt0_entry */ elf_x86_64_lazy_ibt_plt_entry, /* pic_plt_entry */ elf_x86_64_eh_frame_lazy_ibt_plt, /* eh_frame_plt */ sizeof (elf_x86_64_eh_frame_lazy_ibt_plt) /* eh_frame_plt_size */ }; static const struct elf_x86_lazy_plt_layout elf_x32_lazy_ibt_plt = { elf_x86_64_lazy_plt0_entry, /* plt0_entry */ LAZY_PLT_ENTRY_SIZE, /* plt0_entry_size */ elf_x32_lazy_ibt_plt_entry, /* plt_entry */ LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */ elf_x86_64_tlsdesc_plt_entry, /* plt_tlsdesc_entry */ LAZY_PLT_ENTRY_SIZE, /* plt_tlsdesc_entry_size */ 6, /* plt_tlsdesc_got1_offset */ 12, /* plt_tlsdesc_got2_offset */ 10, /* plt_tlsdesc_got1_insn_end */ 16, /* plt_tlsdesc_got2_insn_end */ 2, /* plt0_got1_offset */ 8, /* plt0_got2_offset */ 12, /* plt0_got2_insn_end */ 4+2, /* plt_got_offset */ 4+1, /* plt_reloc_offset */ 4+6, /* plt_plt_offset */ 4+6, /* plt_got_insn_size */ 4+5+5, /* plt_plt_insn_end */ 0, /* plt_lazy_offset */ elf_x86_64_lazy_plt0_entry, /* pic_plt0_entry */ elf_x32_lazy_ibt_plt_entry, /* pic_plt_entry */ elf_x32_eh_frame_lazy_ibt_plt, /* eh_frame_plt */ sizeof (elf_x32_eh_frame_lazy_ibt_plt) /* eh_frame_plt_size */ }; static const struct elf_x86_non_lazy_plt_layout elf_x86_64_non_lazy_ibt_plt = { elf_x86_64_non_lazy_ibt_plt_entry, /* plt_entry */ elf_x86_64_non_lazy_ibt_plt_entry, /* pic_plt_entry */ LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */ 4+1+2, /* plt_got_offset */ 4+1+6, /* plt_got_insn_size */ elf_x86_64_eh_frame_non_lazy_plt, /* eh_frame_plt */ sizeof (elf_x86_64_eh_frame_non_lazy_plt) /* eh_frame_plt_size */ }; static const struct elf_x86_non_lazy_plt_layout elf_x32_non_lazy_ibt_plt = { elf_x32_non_lazy_ibt_plt_entry, /* plt_entry */ elf_x32_non_lazy_ibt_plt_entry, /* pic_plt_entry */ LAZY_PLT_ENTRY_SIZE, /* plt_entry_size */ 4+2, /* plt_got_offset */ 4+6, /* plt_got_insn_size */ elf_x86_64_eh_frame_non_lazy_plt, /* eh_frame_plt */ sizeof (elf_x86_64_eh_frame_non_lazy_plt) /* eh_frame_plt_size */ }; static bool elf64_x86_64_elf_object_p (bfd *abfd) { /* Set the right machine number for an x86-64 elf64 file. */ bfd_default_set_arch_mach (abfd, bfd_arch_i386, bfd_mach_x86_64); return true; } static bool elf32_x86_64_elf_object_p (bfd *abfd) { /* Set the right machine number for an x86-64 elf32 file. */ bfd_default_set_arch_mach (abfd, bfd_arch_i386, bfd_mach_x64_32); return true; } /* Return TRUE if the TLS access code sequence support transition from R_TYPE. */ static bool elf_x86_64_check_tls_transition (bfd *abfd, struct bfd_link_info *info, asection *sec, bfd_byte *contents, Elf_Internal_Shdr *symtab_hdr, struct elf_link_hash_entry **sym_hashes, unsigned int r_type, const Elf_Internal_Rela *rel, const Elf_Internal_Rela *relend) { unsigned int val; unsigned long r_symndx; bool largepic = false; struct elf_link_hash_entry *h; bfd_vma offset; struct elf_x86_link_hash_table *htab; bfd_byte *call; bool indirect_call; htab = elf_x86_hash_table (info, X86_64_ELF_DATA); offset = rel->r_offset; switch (r_type) { case R_X86_64_TLSGD: case R_X86_64_TLSLD: if ((rel + 1) >= relend) return false; if (r_type == R_X86_64_TLSGD) { /* Check transition from GD access model. For 64bit, only .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 can transit to different access model. For 32bit, only 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 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 */ static const unsigned char leaq[] = { 0x66, 0x48, 0x8d, 0x3d }; if ((offset + 12) > sec->size) return false; 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 (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; } else if (ABI_64_P (abfd)) { if (offset < 4 || memcmp (contents + offset - 4, leaq, 4) != 0) return false; } else { if (offset < 3 || 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@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 */ static const unsigned char lea[] = { 0x48, 0x8d, 0x3d }; if (offset < 3 || (offset + 9) > sec->size) return false; if (memcmp (contents + offset - 3, lea, 3) != 0) return false; 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 (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; h = sym_hashes[r_symndx - symtab_hdr->sh_info]; if (h == NULL || !((struct elf_x86_link_hash_entry *) h)->tls_get_addr) return false; else { r_type = (ELF32_R_TYPE (rel[1].r_info) & ~R_X86_64_converted_reloc_bit); if (largepic) return r_type == R_X86_64_PLTOFF64; else if (indirect_call) return (r_type == R_X86_64_GOTPCRELX || r_type == R_X86_64_GOTPCREL); else return (r_type == R_X86_64_PC32 || r_type == R_X86_64_PLT32); } case R_X86_64_CODE_4_GOTTPOFF: /* Check transition from IE access model: mov foo@gottpoff(%rip), %reg add foo@gottpoff(%rip), %reg where reg is one of r16 to r31. */ if (offset < 4 || (offset + 4) > sec->size || contents[offset - 4] != 0xd5) return false; goto check_gottpoff; case R_X86_64_GOTTPOFF: /* Check transition from IE access model: mov foo@gottpoff(%rip), %reg add foo@gottpoff(%rip), %reg */ /* Check REX prefix first. */ if (offset >= 3 && (offset + 4) <= sec->size) { val = bfd_get_8 (abfd, contents + offset - 3); if (val != 0x48 && val != 0x4c) { /* X32 may have 0x44 REX prefix or no REX prefix. */ if (ABI_64_P (abfd)) return false; } } else { /* X32 may not have any REX prefix. */ if (ABI_64_P (abfd)) return false; if (offset < 2 || (offset + 3) > sec->size) return false; } check_gottpoff: val = bfd_get_8 (abfd, contents + offset - 2); if (val != 0x8b && val != 0x03) return false; val = bfd_get_8 (abfd, contents + offset - 1); return (val & 0xc7) == 5; case R_X86_64_CODE_4_GOTPC32_TLSDESC: /* Check transition from GDesc access model: lea x@tlsdesc(%rip), %reg where reg is one of r16 to r31. */ if (offset < 4 || (offset + 4) > sec->size || contents[offset - 4] != 0xd5) return false; goto check_tlsdesc; case R_X86_64_GOTPC32_TLSDESC: /* Check transition from GDesc access model: leaq x@tlsdesc(%rip), %rax <--- LP64 mode. rex leal x@tlsdesc(%rip), %eax <--- X32 mode. Make sure it's a leaq adding rip to a 32-bit offset into any register, although it's probably almost always going to be rax. */ if (offset < 3 || (offset + 4) > sec->size) return false; val = bfd_get_8 (abfd, contents + offset - 3); val &= 0xfb; if (val != 0x48 && (ABI_64_P (abfd) || val != 0x40)) return false; check_tlsdesc: if (bfd_get_8 (abfd, contents + offset - 2) != 0x8d) return false; val = bfd_get_8 (abfd, contents + offset - 1); return (val & 0xc7) == 0x05; case R_X86_64_TLSDESC_CALL: /* Check transition from GDesc access model: call *x@tlsdesc(%rax) <--- LP64 mode. call *x@tlsdesc(%eax) <--- X32 mode. */ if (offset + 2 <= sec->size) { unsigned int prefix; call = contents + offset; prefix = 0; if (!ABI_64_P (abfd)) { /* Check for call *x@tlsdesc(%eax). */ if (call[0] == 0x67) { prefix = 1; if (offset + 3 > sec->size) return false; } } /* Make sure that it's a call *x@tlsdesc(%rax). */ return call[prefix] == 0xff && call[1 + prefix] == 0x10; } return false; default: abort (); } } /* Return TRUE if the TLS access transition is OK or no transition will be performed. Update R_TYPE if there is a transition. */ static bool elf_x86_64_tls_transition (struct bfd_link_info *info, bfd *abfd, asection *sec, bfd_byte *contents, Elf_Internal_Shdr *symtab_hdr, struct elf_link_hash_entry **sym_hashes, unsigned int *r_type, int tls_type, const Elf_Internal_Rela *rel, const Elf_Internal_Rela *relend, struct elf_link_hash_entry *h, unsigned long r_symndx, bool from_relocate_section) { unsigned int from_type = *r_type; unsigned int to_type = from_type; bool check = true; /* Skip TLS transition for functions. */ if (h != NULL && (h->type == STT_FUNC || h->type == STT_GNU_IFUNC)) return true; switch (from_type) { case R_X86_64_TLSGD: case R_X86_64_GOTPC32_TLSDESC: case R_X86_64_CODE_4_GOTPC32_TLSDESC: case R_X86_64_TLSDESC_CALL: case R_X86_64_GOTTPOFF: case R_X86_64_CODE_4_GOTTPOFF: if (bfd_link_executable (info)) { if (h == NULL) to_type = R_X86_64_TPOFF32; else to_type = R_X86_64_GOTTPOFF; } /* 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 (TLS_TRANSITION_IE_TO_LE_P (info, h, tls_type)) new_to_type = R_X86_64_TPOFF32; if (to_type == R_X86_64_TLSGD || to_type == R_X86_64_GOTPC32_TLSDESC || to_type == R_X86_64_CODE_4_GOTPC32_TLSDESC || to_type == R_X86_64_TLSDESC_CALL) { if (tls_type == GOT_TLS_IE) new_to_type = R_X86_64_GOTTPOFF; } /* We checked the transition before when we were called from elf_x86_64_scan_relocs. We only want to check the new transition which hasn't been checked before. */ check = new_to_type != to_type && from_type == to_type; to_type = new_to_type; } break; case R_X86_64_TLSLD: if (bfd_link_executable (info)) to_type = R_X86_64_TPOFF32; break; default: return true; } /* Return TRUE if there is no transition. */ if (from_type == to_type || (from_type == R_X86_64_CODE_4_GOTTPOFF && to_type == R_X86_64_GOTTPOFF)) return true; /* Check if the transition can be performed. */ if (check && ! elf_x86_64_check_tls_transition (abfd, info, sec, contents, symtab_hdr, sym_hashes, from_type, rel, relend)) { reloc_howto_type *from, *to; const char *name; from = elf_x86_64_rtype_to_howto (abfd, from_type); to = elf_x86_64_rtype_to_howto (abfd, to_type); if (from == NULL || to == NULL) return false; if (h) name = h->root.root.string; else { struct elf_x86_link_hash_table *htab; htab = elf_x86_hash_table (info, X86_64_ELF_DATA); if (htab == NULL) name = "*unknown*"; else { Elf_Internal_Sym *isym; isym = bfd_sym_from_r_symndx (&htab->elf.sym_cache, abfd, r_symndx); name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL); } } _bfd_error_handler /* xgettext:c-format */ (_("%pB: TLS transition from %s to %s against `%s' at %#" PRIx64 " in section `%pA' failed"), abfd, from->name, to->name, name, (uint64_t) rel->r_offset, sec); bfd_set_error (bfd_error_bad_value); return false; } *r_type = to_type; return true; } static bool elf_x86_64_need_pic (struct bfd_link_info *info, 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 *object; 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: if (((struct elf_x86_link_hash_entry *) h)->def_protected) v = _("protected symbol "); else v = _("symbol "); pic = NULL; break; } if (!SYMBOL_DEFINED_NON_SHARED_P (h) && !h->def_dynamic) und = _("undefined "); } else { name = bfd_elf_sym_name (input_bfd, symtab_hdr, isym, NULL); pic = NULL; } if (bfd_link_dll (info)) { object = _("a shared object"); if (!pic) pic = _("; recompile with -fPIC"); } else { if (bfd_link_pie (info)) object = _("a PIE object"); else object = _("a PDE object"); if (!pic) pic = _("; recompile with -fPIE"); } /* xgettext:c-format */ _bfd_error_handler (_("%pB: relocation %s against %s%s`%s' can " "not be used when making %s%s"), input_bfd, howto->name, und, v, name, object, 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 bool elf_x86_64_convert_load_reloc (bfd *abfd, bfd_byte *contents, unsigned int *r_type_p, Elf_Internal_Rela *irel, struct elf_link_hash_entry *h, bool *converted, struct bfd_link_info *link_info) { struct elf_x86_link_hash_table *htab; bool is_pic; bool no_overflow; bool relocx; bool to_reloc_pc32; bool abs_symbol; bool local_ref; asection *tsec; bfd_signed_vma raddend; unsigned int opcode; unsigned int modrm; unsigned int r_type = *r_type_p; unsigned int r_symndx; bfd_vma roff = irel->r_offset; bfd_vma abs_relocation; if (roff < (r_type == R_X86_64_CODE_4_GOTPCRELX ? 4 : (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_hash_table (link_info, X86_64_ELF_DATA); is_pic = bfd_link_pic (link_info); if (r_type == R_X86_64_CODE_4_GOTPCRELX) { /* Skip if this isn't a REX2 instruction. */ opcode = bfd_get_8 (abfd, contents + roff - 4); if (opcode != 0xd5) return true; relocx = true; } else relocx = (r_type == R_X86_64_GOTPCRELX || r_type == R_X86_64_REX_GOTPCRELX); /* TRUE if --no-relax is used. */ no_overflow = 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, R_X86_64_REX_GOTPCRELX and R_X86_64_CODE_4_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. no_overflow is true. 4. PIC. */ to_reloc_pc32 = (opcode == 0xff || !relocx || no_overflow || is_pic); abs_symbol = false; abs_relocation = 0; /* Get the symbol referred to by the reloc. */ if (h == NULL) { Elf_Internal_Sym *isym = bfd_sym_from_r_symndx (&htab->elf.sym_cache, abfd, r_symndx); /* Skip relocation against undefined symbols. */ if (isym->st_shndx == SHN_UNDEF) return true; local_ref = true; if (isym->st_shndx == SHN_ABS) { tsec = bfd_abs_section_ptr; abs_symbol = true; abs_relocation = isym->st_value; } 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); } 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. */ struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h); abs_symbol = ABS_SYMBOL_P (h); abs_relocation = h->root.u.def.value; /* NB: Also set linker_def via SYMBOL_REFERENCES_LOCAL_P. */ local_ref = SYMBOL_REFERENCES_LOCAL_P (link_info, h); if ((relocx || opcode == 0x8b) && (h->root.type == bfd_link_hash_undefweak && !eh->linker_def && local_ref)) { if (opcode == 0xff) { /* Skip for branch instructions since R_X86_64_PC32 may overflow. */ if (no_overflow) 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->start_stop || eh->linker_def || ((h->def_regular || h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak) && h != htab->elf.hdynamic && local_ref)) { /* bfd_link_hash_new or bfd_link_hash_undefined is set by an assignment in a linker script in bfd_elf_record_link_assignment. start_stop is set on __start_SECNAME/__stop_SECNAME which mark section SECNAME. */ if (h->start_stop || eh->linker_def || (h->def_regular && (h->root.type == bfd_link_hash_new || h->root.type == bfd_link_hash_undefined || ((h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak) && h->root.u.def.section == bfd_und_section_ptr)))) { /* Skip since R_X86_64_32/R_X86_64_32S may overflow. */ if (no_overflow) return true; goto convert; } tsec = h->root.u.def.section; } 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; /* Skip since R_X86_64_PC32/R_X86_64_32/R_X86_64_32S may overflow. */ if (no_overflow) 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_link_hash_entry *eh = (struct elf_x86_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) { nop = 0x67; nop_offset = irel->r_offset - 2; } else { nop = htab->params->call_nop_byte; if (htab->params->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 = 0; unsigned int rex_mask = REX_R; unsigned int rex2 = 0; unsigned int rex2_mask = REX_R | REX_R << 4; bool rex_w = false; if (r_type == R_X86_64_CODE_4_GOTPCRELX) { rex2 = bfd_get_8 (abfd, contents + roff - 3); rex_w = (rex2 & REX_W) != 0; } else if (r_type == R_X86_64_REX_GOTPCRELX) { rex = bfd_get_8 (abfd, contents + roff - 3); rex_w = (rex & REX_W) != 0; } if (opcode == 0x8b) { if (abs_symbol && local_ref && relocx) to_reloc_pc32 = false; 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_w && 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 and REX2 payload. */ rex_mask |= REX_W; rex2_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_w ? R_X86_64_32S : R_X86_64_32; rewrite_modrm_rex: if (abs_relocation) { /* Check if R_X86_64_32S/R_X86_64_32 fits. */ if (r_type == R_X86_64_32S) { if ((abs_relocation + 0x80000000) > 0xffffffff) return true; } else { if (abs_relocation > 0xffffffff) return true; } } 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); } else if (rex2) { /* Move the R bits to the B bits in REX2 payload byte. */ rex2 = ((rex2 & ~rex2_mask) | (rex2 & (REX_R | REX_R << 4)) >> 2); bfd_put_8 (abfd, rex2, 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); } *r_type_p = r_type; irel->r_info = htab->r_info (r_symndx, r_type | R_X86_64_converted_reloc_bit); *converted = true; return true; } /* Look through the relocs for a section during the first phase, and calculate needed space in the global offset table, and procedure linkage table. */ static bool elf_x86_64_scan_relocs (bfd *abfd, struct bfd_link_info *info, asection *sec, const Elf_Internal_Rela *relocs) { struct elf_x86_link_hash_table *htab; Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes; const Elf_Internal_Rela *rel; const Elf_Internal_Rela *rel_end; bfd_byte *contents; bool converted; if (bfd_link_relocatable (info)) return true; htab = elf_x86_hash_table (info, X86_64_ELF_DATA); if (htab == NULL) { sec->check_relocs_failed = 1; return false; } BFD_ASSERT (is_x86_elf (abfd, htab)); /* 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; } symtab_hdr = &elf_symtab_hdr (abfd); sym_hashes = elf_sym_hashes (abfd); converted = false; rel_end = relocs + sec->reloc_count; for (rel = relocs; rel < rel_end; rel++) { unsigned int r_type; unsigned int r_symndx; struct elf_link_hash_entry *h; struct elf_x86_link_hash_entry *eh; Elf_Internal_Sym *isym; const char *name; bool size_reloc; bool converted_reloc; bool no_dynreloc; r_symndx = htab->r_sym (rel->r_info); r_type = ELF32_R_TYPE (rel->r_info); if (r_symndx >= NUM_SHDR_ENTRIES (symtab_hdr)) { /* xgettext:c-format */ _bfd_error_handler (_("%pB: bad symbol index: %d"), abfd, r_symndx); goto error_return; } if (r_symndx < symtab_hdr->sh_info) { /* A local symbol. */ isym = bfd_sym_from_r_symndx (&htab->elf.sym_cache, abfd, r_symndx); if (isym == NULL) goto error_return; /* Check relocation against local STT_GNU_IFUNC symbol. */ if (ELF_ST_TYPE (isym->st_info) == STT_GNU_IFUNC) { h = _bfd_elf_x86_get_local_sym_hash (htab, abfd, rel, true); if (h == NULL) goto error_return; /* Fake a STT_GNU_IFUNC symbol. */ h->root.root.string = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL); h->type = STT_GNU_IFUNC; h->def_regular = 1; h->ref_regular = 1; h->forced_local = 1; h->root.type = bfd_link_hash_defined; } else h = NULL; } else { isym = NULL; 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; } /* Check invalid x32 relocations. */ if (!ABI_64_P (abfd)) switch (r_type) { default: break; case R_X86_64_DTPOFF64: case R_X86_64_TPOFF64: case R_X86_64_PC64: case R_X86_64_GOTOFF64: case R_X86_64_GOT64: case R_X86_64_GOTPCREL64: case R_X86_64_GOTPC64: case R_X86_64_GOTPLT64: case R_X86_64_PLTOFF64: { if (h) name = h->root.root.string; else name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL); _bfd_error_handler /* xgettext:c-format */ (_("%pB: relocation %s against symbol `%s' isn't " "supported in x32 mode"), abfd, x86_64_elf_howto_table[r_type].name, name); bfd_set_error (bfd_error_bad_value); goto error_return; } break; } eh = (struct elf_x86_link_hash_entry *) h; if (h != NULL) { /* It is referenced by a non-shared object. */ h->ref_regular = 1; } converted_reloc = false; 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_CODE_4_GOTPCRELX) && (h == NULL || h->type != STT_GNU_IFUNC)) { Elf_Internal_Rela *irel = (Elf_Internal_Rela *) rel; if (!elf_x86_64_convert_load_reloc (abfd, contents, &r_type, irel, h, &converted_reloc, info)) goto error_return; if (converted_reloc) converted = true; } if (!_bfd_elf_x86_valid_reloc_p (sec, info, htab, rel, h, isym, symtab_hdr, &no_dynreloc)) return false; if (! elf_x86_64_tls_transition (info, abfd, sec, contents, symtab_hdr, sym_hashes, &r_type, GOT_UNKNOWN, rel, rel_end, h, r_symndx, false)) goto error_return; /* Check if _GLOBAL_OFFSET_TABLE_ is referenced. */ if (h == htab->elf.hgot) htab->got_referenced = true; switch (r_type) { case R_X86_64_TLSLD: htab->tls_ld_or_ldm_got.refcount = 1; goto create_got; case R_X86_64_TPOFF32: if (!bfd_link_executable (info) && ABI_64_P (abfd)) return elf_x86_64_need_pic (info, abfd, sec, h, symtab_hdr, isym, &x86_64_elf_howto_table[r_type]); if (eh != NULL) eh->zero_undefweak &= 0x2; break; case R_X86_64_GOTTPOFF: case R_X86_64_CODE_4_GOTTPOFF: 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_CODE_4_GOTPCRELX: case R_X86_64_TLSGD: case R_X86_64_GOT64: case R_X86_64_GOTPCREL64: case R_X86_64_GOTPLT64: case R_X86_64_GOTPC32_TLSDESC: case R_X86_64_CODE_4_GOTPC32_TLSDESC: case R_X86_64_TLSDESC_CALL: /* This symbol requires a global offset table entry. */ { int tls_type, old_tls_type; switch (r_type) { default: tls_type = GOT_NORMAL; if (h) { if (ABS_SYMBOL_P (h)) tls_type = GOT_ABS; } else if (isym->st_shndx == SHN_ABS) tls_type = GOT_ABS; break; case R_X86_64_TLSGD: tls_type = GOT_TLS_GD; break; case R_X86_64_GOTTPOFF: case R_X86_64_CODE_4_GOTTPOFF: tls_type = GOT_TLS_IE; break; case R_X86_64_GOTPC32_TLSDESC: case R_X86_64_CODE_4_GOTPC32_TLSDESC: case R_X86_64_TLSDESC_CALL: tls_type = GOT_TLS_GDESC; break; } if (h != NULL) { h->got.refcount = 1; old_tls_type = eh->tls_type; } else { bfd_signed_vma *local_got_refcounts; if (!elf_x86_allocate_local_got_info (abfd, symtab_hdr->sh_info)) goto error_return; /* This is a global offset table entry for a local symbol. */ local_got_refcounts = elf_local_got_refcounts (abfd); local_got_refcounts[r_symndx] = 1; old_tls_type = elf_x86_local_got_tls_type (abfd) [r_symndx]; } /* If a TLS symbol is accessed using IE at least once, there is no point to use dynamic model for it. */ if (old_tls_type != tls_type && old_tls_type != GOT_UNKNOWN && (! GOT_TLS_GD_ANY_P (old_tls_type) || tls_type != GOT_TLS_IE)) { if (old_tls_type == GOT_TLS_IE && GOT_TLS_GD_ANY_P (tls_type)) tls_type = old_tls_type; else if (GOT_TLS_GD_ANY_P (old_tls_type) && GOT_TLS_GD_ANY_P (tls_type)) tls_type |= old_tls_type; else { if (h) name = h->root.root.string; else name = bfd_elf_sym_name (abfd, symtab_hdr, isym, NULL); _bfd_error_handler /* xgettext:c-format */ (_("%pB: '%s' accessed both as normal and" " thread local symbol"), abfd, name); bfd_set_error (bfd_error_bad_value); goto error_return; } } if (old_tls_type != tls_type) { if (eh != NULL) eh->tls_type = tls_type; else elf_x86_local_got_tls_type (abfd) [r_symndx] = tls_type; } } /* Fall through */ case R_X86_64_GOTOFF64: case R_X86_64_GOTPC32: case R_X86_64_GOTPC64: create_got: if (eh != NULL) eh->zero_undefweak &= 0x2; break; case R_X86_64_PLT32: /* This symbol requires a procedure linkage table entry. We actually build the entry in adjust_dynamic_symbol, because this might be a case of linking PIC code which is never referenced by a dynamic object, in which case we don't need to generate a procedure linkage table entry after all. */ /* If this is a local symbol, we resolve it directly without creating a procedure linkage table entry. */ if (h == NULL) continue; eh->zero_undefweak &= 0x2; h->needs_plt = 1; h->plt.refcount = 1; break; case R_X86_64_PLTOFF64: /* This tries to form the 'address' of a function relative to GOT. For global symbols we need a PLT entry. */ if (h != NULL) { h->needs_plt = 1; h->plt.refcount = 1; } goto create_got; case R_X86_64_SIZE32: case R_X86_64_SIZE64: size_reloc = true; goto do_size; case R_X86_64_32: if (!ABI_64_P (abfd)) goto pointer; /* Fall through. */ case R_X86_64_8: case R_X86_64_16: case R_X86_64_32S: /* 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 when relocation overflow check is disabled. */ if (!htab->params->no_reloc_overflow_check && !converted_reloc && (bfd_link_pic (info) || (bfd_link_executable (info) && h != NULL && !h->def_regular && h->def_dynamic && (sec->flags & SEC_READONLY) == 0))) return elf_x86_64_need_pic (info, abfd, sec, h, symtab_hdr, isym, &x86_64_elf_howto_table[r_type]); /* Fall through. */ case R_X86_64_PC8: case R_X86_64_PC16: case R_X86_64_PC32: case R_X86_64_PC64: case R_X86_64_64: pointer: if (eh != NULL && (sec->flags & SEC_CODE) != 0) eh->zero_undefweak |= 0x2; /* We are called after all symbols have been resolved. Only relocation against STT_GNU_IFUNC symbol must go through PLT. */ if (h != NULL && (bfd_link_executable (info) || h->type == STT_GNU_IFUNC)) { bool func_pointer_ref = false; 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; if (bfd_link_pie (info) && h->type == STT_FUNC && !h->def_regular && h->def_dynamic) { h->needs_plt = 1; h->plt.refcount = 1; } } } else if (r_type != R_X86_64_PC64) { /* 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. Function pointer reference doesn't need PLT for pointer equality. */ 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)))) func_pointer_ref = true; /* IFUNC symbol needs pointer equality in PDE so that function pointer reference will be resolved to its PLT entry directly. */ if (!func_pointer_ref || (bfd_link_pde (info) && h->type == STT_GNU_IFUNC)) h->pointer_equality_needed = 1; } if (!func_pointer_ref) { /* If this reloc is in a read-only section, we might need a copy reloc. We can't check reliably at this stage whether the section is read-only, as input sections have not yet been mapped to output sections. Tentatively set the flag for now, and correct in adjust_dynamic_symbol. */ h->non_got_ref = 1; if (!elf_has_indirect_extern_access (sec->owner)) eh->non_got_ref_without_indirect_extern_access = 1; /* We may need a .plt entry if the symbol is a function defined in a shared lib or is a function referenced from the code or read-only section. */ if (!h->def_regular || (sec->flags & (SEC_CODE | SEC_READONLY)) != 0) h->plt.refcount = 1; if (htab->elf.target_os != is_solaris && h->pointer_equality_needed && h->type == STT_FUNC && eh->def_protected && !SYMBOL_DEFINED_NON_SHARED_P (h) && h->def_dynamic) { /* Disallow non-canonical reference to canonical protected function. */ _bfd_error_handler /* xgettext:c-format */ (_("%pB: non-canonical reference to canonical " "protected function `%s' in %pB"), abfd, h->root.root.string, h->root.u.def.section->owner); bfd_set_error (bfd_error_bad_value); goto error_return; } } } size_reloc = false; do_size: if (!no_dynreloc && NEED_DYNAMIC_RELOCATION_P (true, info, true, h, sec, r_type, htab->pointer_r_type)) { struct elf_dyn_relocs *p; struct elf_dyn_relocs **head; /* If this is a global symbol, we count the number of relocations we need for this symbol. */ if (h != NULL) head = &h->dyn_relocs; else { /* Track dynamic relocs needed for local syms too. We really need local syms available to do this easily. Oh well. */ asection *s; void **vpp; isym = bfd_sym_from_r_symndx (&htab->elf.sym_cache, abfd, r_symndx); if (isym == NULL) goto error_return; s = bfd_section_from_elf_index (abfd, isym->st_shndx); if (s == NULL) s = sec; /* Beware of type punned pointers vs strict aliasing rules. */ vpp = &(elf_section_data (s)->local_dynrel); head = (struct elf_dyn_relocs **)vpp; } p = *head; if (p == NULL || p->sec != sec) { size_t amt = sizeof *p; p = ((struct elf_dyn_relocs *) bfd_alloc (htab->elf.dynobj, amt)); if (p == NULL) goto error_return; p->next = *head; *head = p; p->sec = sec; p->count = 0; p->pc_count = 0; } p->count += 1; /* Count size relocation as PC-relative relocation. */ if (X86_PCREL_TYPE_P (true, r_type) || size_reloc) p->pc_count += 1; } break; /* This relocation describes the C++ object vtable hierarchy. 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)) goto error_return; break; /* This relocation describes which C++ vtable entries are actually used. Record for later use during GC. */ case R_X86_64_GNU_VTENTRY: if (!bfd_elf_gc_record_vtentry (abfd, sec, h, rel->r_addend)) goto error_return; break; default: break; } } if (elf_section_data (sec)->this_hdr.contents != contents) { if (!converted && !_bfd_link_keep_memory (info)) free (contents); else { /* Cache the section contents for elf_link_input_bfd if any load is converted or --no-keep-memory isn't used. */ elf_section_data (sec)->this_hdr.contents = contents; info->cache_size += sec->size; } } /* Cache relocations if any load is converted. */ if (elf_section_data (sec)->relocs != relocs && converted) elf_section_data (sec)->relocs = (Elf_Internal_Rela *) relocs; return true; error_return: if (elf_section_data (sec)->this_hdr.contents != contents) free (contents); sec->check_relocs_failed = 1; return false; } static bool elf_x86_64_always_size_sections (bfd *output_bfd, struct bfd_link_info *info) { bfd *abfd; /* Scan relocations after rel_from_abs has been set on __ehdr_start. */ for (abfd = info->input_bfds; abfd != (bfd *) NULL; abfd = abfd->link.next) if (bfd_get_flavour (abfd) == bfd_target_elf_flavour && !_bfd_elf_link_iterate_on_relocs (abfd, info, elf_x86_64_scan_relocs)) return false; return _bfd_x86_elf_always_size_sections (output_bfd, info); } /* Return the relocation value for @tpoff relocation if STT_TLS virtual address is ADDRESS. */ static bfd_vma elf_x86_64_tpoff (struct bfd_link_info *info, bfd_vma address) { struct elf_link_hash_table *htab = elf_hash_table (info); const struct elf_backend_data *bed = get_elf_backend_data (info->output_bfd); bfd_vma static_tls_size; /* If tls_segment is NULL, we should have signalled an error already. */ if (htab->tls_sec == NULL) return 0; /* Consider special static TLS alignment requirements. */ static_tls_size = BFD_ALIGN (htab->tls_size, bed->static_tls_alignment); return address - static_tls_size - htab->tls_sec->vma; } /* Relocate an x86_64 ELF section. */ static int elf_x86_64_relocate_section (bfd *output_bfd, struct bfd_link_info *info, bfd *input_bfd, asection *input_section, bfd_byte *contents, Elf_Internal_Rela *relocs, Elf_Internal_Sym *local_syms, asection **local_sections) { struct elf_x86_link_hash_table *htab; Elf_Internal_Shdr *symtab_hdr; struct elf_link_hash_entry **sym_hashes; bfd_vma *local_got_offsets; bfd_vma *local_tlsdesc_gotents; Elf_Internal_Rela *rel; Elf_Internal_Rela *wrel; Elf_Internal_Rela *relend; unsigned int plt_entry_size; bool status; /* Skip if check_relocs or scan_relocs failed. */ if (input_section->check_relocs_failed) return false; htab = elf_x86_hash_table (info, X86_64_ELF_DATA); if (htab == NULL) return false; if (!is_x86_elf (input_bfd, htab)) { bfd_set_error (bfd_error_wrong_format); return false; } plt_entry_size = htab->plt.plt_entry_size; symtab_hdr = &elf_symtab_hdr (input_bfd); sym_hashes = elf_sym_hashes (input_bfd); local_got_offsets = elf_local_got_offsets (input_bfd); local_tlsdesc_gotents = elf_x86_local_tlsdesc_gotent (input_bfd); _bfd_x86_elf_set_tls_module_base (info); status = true; rel = wrel = relocs; relend = relocs + input_section->reloc_count; for (; rel < relend; wrel++, rel++) { unsigned int r_type, r_type_tls; reloc_howto_type *howto; unsigned long r_symndx; struct elf_link_hash_entry *h; struct elf_x86_link_hash_entry *eh; Elf_Internal_Sym *sym; asection *sec; bfd_vma off, offplt, plt_offset; bfd_vma relocation; bool unresolved_reloc; bfd_reloc_status_type r; int tls_type; asection *base_got, *resolved_plt; bfd_vma st_size; bool resolved_to_zero; bool relative_reloc; bool converted_reloc; bool need_copy_reloc_in_pie; bool no_copyreloc_p; 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) { if (wrel != rel) *wrel = *rel; continue; } r_symndx = htab->r_sym (rel->r_info); converted_reloc = (r_type & R_X86_64_converted_reloc_bit) != 0; if (converted_reloc) { r_type &= ~R_X86_64_converted_reloc_bit; rel->r_info = htab->r_info (r_symndx, r_type); } howto = elf_x86_64_rtype_to_howto (input_bfd, r_type); if (howto == NULL) return _bfd_unrecognized_reloc (input_bfd, input_section, r_type); h = NULL; sym = NULL; sec = NULL; unresolved_reloc = false; if (r_symndx < symtab_hdr->sh_info) { sym = local_syms + r_symndx; sec = local_sections[r_symndx]; relocation = _bfd_elf_rela_local_sym (output_bfd, sym, &sec, rel); st_size = sym->st_size; /* Relocate against local STT_GNU_IFUNC symbol. */ if (!bfd_link_relocatable (info) && ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC) { h = _bfd_elf_x86_get_local_sym_hash (htab, input_bfd, rel, false); if (h == NULL) abort (); /* Set STT_GNU_IFUNC symbol value. */ h->root.u.def.value = sym->st_value; h->root.u.def.section = sec; } } else { bool warned ATTRIBUTE_UNUSED; bool ignored ATTRIBUTE_UNUSED; RELOC_FOR_GLOBAL_SYMBOL (info, input_bfd, input_section, rel, r_symndx, symtab_hdr, sym_hashes, h, sec, relocation, unresolved_reloc, warned, ignored); st_size = h->size; } if (sec != NULL && discarded_section (sec)) { _bfd_clear_contents (howto, input_bfd, input_section, contents, rel->r_offset); wrel->r_offset = rel->r_offset; wrel->r_info = 0; wrel->r_addend = 0; /* For ld -r, remove relocations in debug sections against sections defined in discarded sections. Not done for eh_frame editing code expects to be present. */ if (bfd_link_relocatable (info) && (input_section->flags & SEC_DEBUGGING)) wrel--; continue; } if (bfd_link_relocatable (info)) { if (wrel != rel) *wrel = *rel; continue; } if (rel->r_addend == 0 && !ABI_64_P (output_bfd)) { if (r_type == R_X86_64_64) { /* For x32, treat R_X86_64_64 like R_X86_64_32 and zero-extend it to 64bit if addend is zero. */ r_type = R_X86_64_32; memset (contents + rel->r_offset + 4, 0, 4); } else if (r_type == R_X86_64_SIZE64) { /* For x32, treat R_X86_64_SIZE64 like R_X86_64_SIZE32 and zero-extend it to 64bit if addend is zero. */ r_type = R_X86_64_SIZE32; memset (contents + rel->r_offset + 4, 0, 4); } } eh = (struct elf_x86_link_hash_entry *) h; /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it here if it is defined in a non-shared object. */ if (h != NULL && h->type == STT_GNU_IFUNC && h->def_regular) { bfd_vma plt_index; const char *name; if ((input_section->flags & SEC_ALLOC) == 0) { /* If this is a SHT_NOTE section without SHF_ALLOC, treat STT_GNU_IFUNC symbol as STT_FUNC. */ if (elf_section_type (input_section) == SHT_NOTE) goto skip_ifunc; /* Dynamic relocs are not propagated for SEC_DEBUGGING sections because such sections are not SEC_ALLOC and thus ld.so will not process them. */ if ((input_section->flags & SEC_DEBUGGING) != 0) continue; abort (); } switch (r_type) { default: break; case R_X86_64_GOTPCREL: case R_X86_64_GOTPCRELX: case R_X86_64_REX_GOTPCRELX: case R_X86_64_CODE_4_GOTPCRELX: case R_X86_64_GOTPCREL64: base_got = htab->elf.sgot; off = h->got.offset; if (base_got == NULL) abort (); if (off == (bfd_vma) -1) { /* We can't use h->got.offset here to save state, or even just remember the offset, as finish_dynamic_symbol would use that as offset into .got. */ if (h->plt.offset == (bfd_vma) -1) abort (); if (htab->elf.splt != NULL) { plt_index = (h->plt.offset / plt_entry_size - htab->plt.has_plt0); off = (plt_index + 3) * GOT_ENTRY_SIZE; base_got = htab->elf.sgotplt; } else { plt_index = h->plt.offset / plt_entry_size; off = plt_index * GOT_ENTRY_SIZE; base_got = htab->elf.igotplt; } if (h->dynindx == -1 || h->forced_local || info->symbolic) { /* This references the local defitionion. We must initialize this entry in the global offset table. Since the offset must always be a multiple of 8, we use the least significant bit to record whether we have initialized it already. When doing a dynamic link, we create a .rela.got relocation entry to initialize the value. This is done in the finish_dynamic_symbol routine. */ if ((off & 1) != 0) off &= ~1; else { bfd_put_64 (output_bfd, relocation, base_got->contents + off); /* Note that this is harmless for the GOTPLT64 case, as -1 | 1 still is -1. */ h->got.offset |= 1; } } } relocation = (base_got->output_section->vma + base_got->output_offset + off); goto do_relocation; } if (h->plt.offset == (bfd_vma) -1) { /* Handle static pointers of STT_GNU_IFUNC symbols. */ if (r_type == htab->pointer_r_type && (input_section->flags & SEC_CODE) == 0) goto do_ifunc_pointer; goto bad_ifunc_reloc; } /* STT_GNU_IFUNC symbol must go through PLT. */ if (htab->elf.splt != NULL) { if (htab->plt_second != NULL) { resolved_plt = htab->plt_second; plt_offset = eh->plt_second.offset; } else { resolved_plt = htab->elf.splt; plt_offset = h->plt.offset; } } else { resolved_plt = htab->elf.iplt; plt_offset = h->plt.offset; } relocation = (resolved_plt->output_section->vma + resolved_plt->output_offset + plt_offset); switch (r_type) { default: bad_ifunc_reloc: if (h->root.root.string) name = h->root.root.string; else name = bfd_elf_sym_name (input_bfd, symtab_hdr, sym, NULL); _bfd_error_handler /* xgettext:c-format */ (_("%pB: relocation %s against STT_GNU_IFUNC " "symbol `%s' isn't supported"), input_bfd, howto->name, name); bfd_set_error (bfd_error_bad_value); return false; case R_X86_64_32S: if (bfd_link_pic (info)) abort (); goto do_relocation; case R_X86_64_32: if (ABI_64_P (output_bfd)) goto do_relocation; /* FALLTHROUGH */ case R_X86_64_64: do_ifunc_pointer: if (rel->r_addend != 0) { if (h->root.root.string) name = h->root.root.string; else name = bfd_elf_sym_name (input_bfd, symtab_hdr, sym, NULL); _bfd_error_handler /* xgettext:c-format */ (_("%pB: relocation %s against STT_GNU_IFUNC " "symbol `%s' has non-zero addend: %" PRId64), input_bfd, howto->name, name, (int64_t) 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 or there is no PLT. */ if ((bfd_link_pic (info) && h->non_got_ref) || h->plt.offset == (bfd_vma) -1) { Elf_Internal_Rela outrel; asection *sreloc; /* Need a dynamic relocation to get the real function address. */ outrel.r_offset = _bfd_elf_section_offset (output_bfd, info, input_section, rel->r_offset); if (outrel.r_offset == (bfd_vma) -1 || outrel.r_offset == (bfd_vma) -2) abort (); outrel.r_offset += (input_section->output_section->vma + input_section->output_offset); if (POINTER_LOCAL_IFUNC_P (info, h)) { info->callbacks->minfo (_("Local IFUNC function `%s' in %pB\n"), h->root.root.string, h->root.u.def.section->owner); /* This symbol is resolved locally. */ outrel.r_info = htab->r_info (0, R_X86_64_IRELATIVE); outrel.r_addend = (h->root.u.def.value + h->root.u.def.section->output_section->vma + h->root.u.def.section->output_offset); if (htab->params->report_relative_reloc) _bfd_x86_elf_link_report_relative_reloc (info, input_section, h, sym, "R_X86_64_IRELATIVE", &outrel); } else { outrel.r_info = htab->r_info (h->dynindx, r_type); outrel.r_addend = 0; } /* Dynamic relocations are stored in 1. .rela.ifunc section in PIC object. 2. .rela.got section in dynamic executable. 3. .rela.iplt section in static executable. */ if (bfd_link_pic (info)) sreloc = htab->elf.irelifunc; else if (htab->elf.splt != NULL) sreloc = htab->elf.srelgot; else sreloc = htab->elf.irelplt; elf_append_rela (output_bfd, sreloc, &outrel); /* If this reloc is against an external symbol, we do not want to fiddle with the addend. Otherwise, we need to include the symbol value so that it becomes an addend for the dynamic reloc. For an internal symbol, we have updated addend. */ continue; } /* FALLTHROUGH */ case R_X86_64_PC32: case R_X86_64_PC64: case R_X86_64_PLT32: goto do_relocation; } } skip_ifunc: resolved_to_zero = (eh != NULL && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, 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) { case R_X86_64_GOT32: case R_X86_64_GOT64: /* 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_CODE_4_GOTPCRELX: case R_X86_64_GOTPCREL64: /* Use global offset table entry as symbol value. */ case R_X86_64_GOTPLT64: /* This is obsolete and treated the same as GOT64. */ base_got = htab->elf.sgot; if (htab->elf.sgot == NULL) abort (); relative_reloc = false; if (h != NULL) { off = h->got.offset; if (h->needs_plt && h->plt.offset != (bfd_vma)-1 && off == (bfd_vma)-1) { /* We can't use h->got.offset here to save state, or even just remember the offset, as finish_dynamic_symbol would use that as offset into .got. */ bfd_vma plt_index = (h->plt.offset / plt_entry_size - htab->plt.has_plt0); off = (plt_index + 3) * GOT_ENTRY_SIZE; base_got = htab->elf.sgotplt; } if (RESOLVED_LOCALLY_P (info, h, htab)) { /* We must initialize this entry in the global offset table. Since the offset must always be a multiple of 8, we use the least significant bit to record whether we have initialized it already. When doing a dynamic link, we create a .rela.got relocation entry to initialize the value. This is done in the finish_dynamic_symbol routine. */ if ((off & 1) != 0) off &= ~1; else { bfd_put_64 (output_bfd, relocation, base_got->contents + off); /* Note that this is harmless for the GOTPLT64 case, as -1 | 1 still is -1. */ h->got.offset |= 1; /* NB: Don't generate relative relocation here if it has been generated by DT_RELR. */ if (!info->enable_dt_relr && GENERATE_RELATIVE_RELOC_P (info, h)) { /* If this symbol isn't dynamic in PIC, generate R_X86_64_RELATIVE here. */ eh->no_finish_dynamic_symbol = 1; relative_reloc = true; } } } else unresolved_reloc = false; } else { if (local_got_offsets == NULL) abort (); off = local_got_offsets[r_symndx]; /* The offset must always be a multiple of 8. We use the least significant bit to record whether we have already generated the necessary reloc. */ if ((off & 1) != 0) off &= ~1; else { bfd_put_64 (output_bfd, relocation, base_got->contents + off); local_got_offsets[r_symndx] |= 1; /* NB: GOTPCREL relocations against local absolute symbol store relocation value in the GOT slot without relative relocation. Don't generate relative relocation here if it has been generated by DT_RELR. */ if (!info->enable_dt_relr && bfd_link_pic (info) && !(sym->st_shndx == SHN_ABS && (r_type == R_X86_64_GOTPCREL || r_type == R_X86_64_GOTPCRELX || r_type == R_X86_64_REX_GOTPCRELX || r_type == R_X86_64_CODE_4_GOTPCRELX))) relative_reloc = true; } } if (relative_reloc) { asection *s; Elf_Internal_Rela outrel; /* We need to generate a R_X86_64_RELATIVE reloc for the dynamic linker. */ s = htab->elf.srelgot; if (s == NULL) abort (); outrel.r_offset = (base_got->output_section->vma + base_got->output_offset + off); outrel.r_info = htab->r_info (0, R_X86_64_RELATIVE); outrel.r_addend = relocation; if (htab->params->report_relative_reloc) _bfd_x86_elf_link_report_relative_reloc (info, input_section, h, sym, "R_X86_64_RELATIVE", &outrel); elf_append_rela (output_bfd, s, &outrel); } if (off >= (bfd_vma) -2) abort (); relocation = base_got->output_section->vma + base_got->output_offset + off; 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_CODE_4_GOTPCRELX && r_type != R_X86_64_GOTPCREL64) relocation -= htab->elf.sgotplt->output_section->vma - htab->elf.sgotplt->output_offset; break; case R_X86_64_GOTOFF64: /* Relocation is relative to the start of the global offset table. */ /* Check to make sure it isn't a protected function or data 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 (bfd_link_pic (info) && h) { if (!h->def_regular) { const char *v; 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"); break; } _bfd_error_handler /* xgettext:c-format */ (_("%pB: relocation R_X86_64_GOTOFF64 against undefined %s" " `%s' can not be used when making a shared object"), input_bfd, v, h->root.root.string); bfd_set_error (bfd_error_bad_value); return false; } else if (!bfd_link_executable (info) && !SYMBOL_REFERENCES_LOCAL_P (info, h) && (h->type == STT_FUNC || h->type == STT_OBJECT) && ELF_ST_VISIBILITY (h->other) == STV_PROTECTED) { _bfd_error_handler /* xgettext:c-format */ (_("%pB: relocation R_X86_64_GOTOFF64 against protected %s" " `%s' can not be used when making a shared object"), input_bfd, h->type == STT_FUNC ? "function" : "data", h->root.root.string); bfd_set_error (bfd_error_bad_value); return false; } } /* Note that sgot is not involved in this calculation. We always want the start of .got.plt. If we defined _GLOBAL_OFFSET_TABLE_ in a different way, as is permitted by the ABI, we might have to change this calculation. */ relocation -= htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset; break; case R_X86_64_GOTPC32: case R_X86_64_GOTPC64: /* Use global offset table as symbol value. */ relocation = htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset; unresolved_reloc = false; break; case R_X86_64_PLTOFF64: /* Relocation is PLT entry relative to GOT. For local symbols it's the symbol itself relative to GOT. */ if (h != NULL /* See PLT32 handling. */ && (h->plt.offset != (bfd_vma) -1 || eh->plt_got.offset != (bfd_vma) -1) && htab->elf.splt != NULL) { if (eh->plt_got.offset != (bfd_vma) -1) { /* Use the GOT PLT. */ resolved_plt = htab->plt_got; plt_offset = eh->plt_got.offset; } else if (htab->plt_second != NULL) { resolved_plt = htab->plt_second; plt_offset = eh->plt_second.offset; } else { resolved_plt = htab->elf.splt; plt_offset = h->plt.offset; } relocation = (resolved_plt->output_section->vma + resolved_plt->output_offset + plt_offset); unresolved_reloc = false; } relocation -= htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset; break; case R_X86_64_PLT32: /* Relocation is to the entry for this symbol in the procedure linkage table. */ /* Resolve a PLT32 reloc against a local symbol directly, without using the procedure linkage table. */ if (h == NULL) break; if ((h->plt.offset == (bfd_vma) -1 && eh->plt_got.offset == (bfd_vma) -1) || htab->elf.splt == NULL) { /* We didn't make a PLT entry for this symbol. This happens when statically linking PIC code, or when using -Bsymbolic. */ break; } use_plt: if (h->plt.offset != (bfd_vma) -1) { if (htab->plt_second != NULL) { resolved_plt = htab->plt_second; plt_offset = eh->plt_second.offset; } else { resolved_plt = htab->elf.splt; plt_offset = h->plt.offset; } } else { /* Use the GOT PLT. */ resolved_plt = htab->plt_got; plt_offset = eh->plt_got.offset; } relocation = (resolved_plt->output_section->vma + resolved_plt->output_offset + plt_offset); unresolved_reloc = false; break; case R_X86_64_SIZE32: case R_X86_64_SIZE64: /* Set to symbol size. */ relocation = st_size; goto direct; case R_X86_64_PC8: case R_X86_64_PC16: case R_X86_64_PC32: /* Don't complain about -fPIC if the symbol is undefined when building executable unless it is unresolved weak symbol, references a dynamic definition in PIE or -z nocopyreloc is used. */ no_copyreloc_p = (info->nocopyreloc || (h != NULL && !h->root.linker_def && !h->root.ldscript_def && eh->def_protected)); if ((input_section->flags & SEC_ALLOC) != 0 && (input_section->flags & SEC_READONLY) != 0 && h != NULL && ((bfd_link_executable (info) && ((h->root.type == bfd_link_hash_undefweak && (eh == NULL || !UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh))) || (bfd_link_pie (info) && !SYMBOL_DEFINED_NON_SHARED_P (h) && h->def_dynamic) || (no_copyreloc_p && h->def_dynamic && !(h->root.u.def.section->flags & SEC_CODE)))) || (bfd_link_pie (info) && h->root.type == bfd_link_hash_undefweak) || bfd_link_dll (info))) { bool fail = false; if (SYMBOL_REFERENCES_LOCAL_P (info, h)) { /* Symbol is referenced locally. Make sure it is defined locally. */ fail = !SYMBOL_DEFINED_NON_SHARED_P (h); } else if (bfd_link_pie (info)) { /* We can only use PC-relative relocations in PIE from non-code sections. */ if (h->root.type == bfd_link_hash_undefweak || (h->type == STT_FUNC && (sec->flags & SEC_CODE) != 0)) fail = true; } else if (no_copyreloc_p || bfd_link_dll (info)) { /* Symbol doesn't need copy reloc and isn't referenced locally. Don't allow PC-relative relocations against default and protected symbols since address of protected function and location of protected data may not be in the shared object. */ fail = (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT || ELF_ST_VISIBILITY (h->other) == STV_PROTECTED); } if (fail) return elf_x86_64_need_pic (info, input_bfd, input_section, h, NULL, NULL, howto); } /* Since x86-64 has PC-relative PLT, we can use PLT in PIE as function address. */ else if (h != NULL && (input_section->flags & SEC_CODE) == 0 && bfd_link_pie (info) && h->type == STT_FUNC && !h->def_regular && h->def_dynamic) goto use_plt; /* Fall through. */ case R_X86_64_8: case R_X86_64_16: case R_X86_64_32: case R_X86_64_PC64: case R_X86_64_64: /* FIXME: The ABI says the linker should make sure the value is the same when it's zeroextended to 64 bit. */ direct: if ((input_section->flags & SEC_ALLOC) == 0) break; need_copy_reloc_in_pie = (bfd_link_pie (info) && h != NULL && (h->needs_copy || eh->needs_copy || (h->root.type == bfd_link_hash_undefined)) && (X86_PCREL_TYPE_P (true, r_type) || X86_SIZE_TYPE_P (true, r_type))); if (GENERATE_DYNAMIC_RELOCATION_P (true, info, eh, r_type, sec, need_copy_reloc_in_pie, resolved_to_zero, false)) { Elf_Internal_Rela outrel; bool skip, relocate; bool generate_dynamic_reloc = true; asection *sreloc; const char *relative_reloc_name = NULL; /* When generating a shared object, these relocations are copied into the output file to be resolved at run time. */ skip = false; relocate = false; outrel.r_offset = _bfd_elf_section_offset (output_bfd, info, input_section, rel->r_offset); if (outrel.r_offset == (bfd_vma) -1) skip = true; else if (outrel.r_offset == (bfd_vma) -2) skip = true, relocate = true; outrel.r_offset += (input_section->output_section->vma + input_section->output_offset); if (skip) memset (&outrel, 0, sizeof outrel); else if (COPY_INPUT_RELOC_P (true, info, h, r_type)) { outrel.r_info = htab->r_info (h->dynindx, r_type); outrel.r_addend = rel->r_addend; } else { /* 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 && htab->params->no_reloc_overflow_check)) { relocate = true; /* NB: Don't generate relative relocation here if it has been generated by DT_RELR. */ if (info->enable_dt_relr) generate_dynamic_reloc = false; else { outrel.r_info = htab->r_info (0, R_X86_64_RELATIVE); outrel.r_addend = relocation + rel->r_addend; relative_reloc_name = "R_X86_64_RELATIVE"; } } else if (r_type == R_X86_64_64 && !ABI_64_P (output_bfd)) { relocate = true; outrel.r_info = htab->r_info (0, R_X86_64_RELATIVE64); outrel.r_addend = relocation + rel->r_addend; relative_reloc_name = "R_X86_64_RELATIVE64"; /* Check addend overflow. */ if ((outrel.r_addend & 0x80000000) != (rel->r_addend & 0x80000000)) { const char *name; int addend = rel->r_addend; if (h && h->root.root.string) name = h->root.root.string; else name = bfd_elf_sym_name (input_bfd, symtab_hdr, sym, NULL); _bfd_error_handler /* xgettext:c-format */ (_("%pB: addend %s%#x in relocation %s against " "symbol `%s' at %#" PRIx64 " in section `%pA' is out of range"), input_bfd, addend < 0 ? "-" : "", addend, howto->name, name, (uint64_t) rel->r_offset, input_section); bfd_set_error (bfd_error_bad_value); return false; } } else { long sindx; if (bfd_is_abs_section (sec)) sindx = 0; else if (sec == NULL || sec->owner == NULL) { bfd_set_error (bfd_error_bad_value); return false; } else { asection *osec; /* We are turning this relocation into one against a section symbol. It would be proper to subtract the symbol's value, osec->vma, from the emitted reloc addend, but ld.so expects buggy relocs. */ osec = sec->output_section; sindx = elf_section_data (osec)->dynindx; if (sindx == 0) { asection *oi = htab->elf.text_index_section; sindx = elf_section_data (oi)->dynindx; } BFD_ASSERT (sindx != 0); } outrel.r_info = htab->r_info (sindx, r_type); outrel.r_addend = relocation + rel->r_addend; } } if (generate_dynamic_reloc) { sreloc = elf_section_data (input_section)->sreloc; if (sreloc == NULL || sreloc->contents == NULL) { r = bfd_reloc_notsupported; goto check_relocation_error; } if (relative_reloc_name && htab->params->report_relative_reloc) _bfd_x86_elf_link_report_relative_reloc (info, input_section, h, sym, relative_reloc_name, &outrel); elf_append_rela (output_bfd, sreloc, &outrel); } /* If this reloc is against an external symbol, we do not want to fiddle with the addend. Otherwise, we need to include the symbol value so that it becomes an addend for the dynamic reloc. */ if (! relocate) continue; } break; case R_X86_64_TLSGD: case R_X86_64_GOTPC32_TLSDESC: case R_X86_64_CODE_4_GOTPC32_TLSDESC: case R_X86_64_TLSDESC_CALL: case R_X86_64_GOTTPOFF: case R_X86_64_CODE_4_GOTTPOFF: tls_type = GOT_UNKNOWN; if (h == NULL && local_got_offsets) tls_type = elf_x86_local_got_tls_type (input_bfd) [r_symndx]; else if (h != NULL) tls_type = elf_x86_hash_entry (h)->tls_type; r_type_tls = r_type; if (! elf_x86_64_tls_transition (info, input_bfd, input_section, contents, symtab_hdr, sym_hashes, &r_type_tls, tls_type, rel, relend, h, r_symndx, true)) return false; if (r_type_tls == R_X86_64_TPOFF32) { bfd_vma roff = rel->r_offset; if (roff >= input_section->size) goto corrupt_input; BFD_ASSERT (! unresolved_reloc); if (r_type == R_X86_64_TLSGD) { /* GD->LE transition. For 64bit, change .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 For 32bit, change 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 For largepic, change: 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) */ int largepic = 0; if (ABI_64_P (output_bfd)) { if (roff + 5 >= input_section->size) goto corrupt_input; if (contents[roff + 5] == 0xb8) { if (roff < 3 || (roff - 3 + 22) > input_section->size) { corrupt_input: info->callbacks->einfo (_("%F%P: corrupt input: %pB\n"), input_bfd); return false; } 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 { if (roff < 4 || (roff - 4 + 16) > input_section->size) goto corrupt_input; memcpy (contents + roff - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0", 16); } } else { if (roff < 3 || (roff - 3 + 15) > input_section->size) goto corrupt_input; memcpy (contents + roff - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0", 15); } if (roff + 8 + largepic >= input_section->size) goto corrupt_input; 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_GOTPCRELX and R_X86_64_PLTOFF64. */ rel++; wrel++; continue; } else if (r_type == R_X86_64_GOTPC32_TLSDESC) { /* GDesc -> LE transition. It's originally something like: leaq x@tlsdesc(%rip), %rax <--- LP64 mode. rex leal x@tlsdesc(%rip), %eax <--- X32 mode. Change it to: movq $x@tpoff, %rax <--- LP64 mode. rex movl $x@tpoff, %eax <--- X32 mode. */ unsigned int val, type; if (roff < 3) goto corrupt_input; type = bfd_get_8 (input_bfd, contents + roff - 3); val = bfd_get_8 (input_bfd, contents + roff - 1); bfd_put_8 (output_bfd, (type & 0x48) | ((type >> 2) & 1), contents + roff - 3); bfd_put_8 (output_bfd, 0xc7, contents + roff - 2); bfd_put_8 (output_bfd, 0xc0 | ((val >> 3) & 7), contents + roff - 1); bfd_put_32 (output_bfd, elf_x86_64_tpoff (info, relocation), contents + roff); continue; } else if (r_type == R_X86_64_CODE_4_GOTPC32_TLSDESC) { /* GDesc -> LE transition. It's originally something like: lea x@tlsdesc(%rip), %reg Change it to: mov $x@tpoff, %reg where reg is one of r16 to r31. */ unsigned int val, rex2; unsigned int rex2_mask = REX_R | REX_R << 4; if (roff < 4) goto corrupt_input; rex2 = bfd_get_8 (input_bfd, contents + roff - 3); val = bfd_get_8 (input_bfd, contents + roff - 1); /* Move the R bits to the B bits in REX2 payload byte. */ bfd_put_8 (output_bfd, ((rex2 & ~rex2_mask) | (rex2 & rex2_mask) >> 2), contents + roff - 3); bfd_put_8 (output_bfd, 0xc7, contents + roff - 2); bfd_put_8 (output_bfd, 0xc0 | ((val >> 3) & 7), contents + roff - 1); bfd_put_32 (output_bfd, elf_x86_64_tpoff (info, relocation), contents + roff); continue; } else if (r_type == R_X86_64_TLSDESC_CALL) { /* GDesc -> LE transition. It's originally: call *(%rax) <--- LP64 mode. call *(%eax) <--- X32 mode. Turn it into: xchg %ax,%ax <-- LP64 mode. nopl (%rax) <-- X32 mode. */ unsigned int prefix = 0; if (!ABI_64_P (input_bfd)) { /* Check for call *x@tlsdesc(%eax). */ if (contents[roff] == 0x67) prefix = 1; } if (prefix) { if (roff + 2 >= input_section->size) goto corrupt_input; bfd_put_8 (output_bfd, 0x0f, contents + roff); bfd_put_8 (output_bfd, 0x1f, contents + roff + 1); bfd_put_8 (output_bfd, 0x00, contents + roff + 2); } else { if (roff + 1 >= input_section->size) goto corrupt_input; bfd_put_8 (output_bfd, 0x66, contents + roff); bfd_put_8 (output_bfd, 0x90, contents + roff + 1); } continue; } else if (r_type == R_X86_64_GOTTPOFF) { /* IE->LE transition: For 64bit, originally it can be one of: movq foo@gottpoff(%rip), %reg addq foo@gottpoff(%rip), %reg We change it into: movq $foo, %reg leaq foo(%reg), %reg addq $foo, %reg. For 32bit, originally it can be one of: movq foo@gottpoff(%rip), %reg addl foo@gottpoff(%rip), %reg We change it into: movq $foo, %reg leal foo(%reg), %reg addl $foo, %reg. */ unsigned int val, type, reg; if (roff >= 3) val = bfd_get_8 (input_bfd, contents + roff - 3); else { if (roff < 2) goto corrupt_input; val = 0; } type = bfd_get_8 (input_bfd, contents + roff - 2); reg = bfd_get_8 (input_bfd, contents + roff - 1); reg >>= 3; if (type == 0x8b) { /* movq */ if (val == 0x4c) { if (roff < 3) goto corrupt_input; bfd_put_8 (output_bfd, 0x49, contents + roff - 3); } else if (!ABI_64_P (output_bfd) && val == 0x44) { if (roff < 3) goto corrupt_input; bfd_put_8 (output_bfd, 0x41, contents + roff - 3); } bfd_put_8 (output_bfd, 0xc7, contents + roff - 2); bfd_put_8 (output_bfd, 0xc0 | reg, contents + roff - 1); } else if (reg == 4) { /* addq/addl -> addq/addl - addressing with %rsp/%r12 is special */ if (val == 0x4c) { if (roff < 3) goto corrupt_input; bfd_put_8 (output_bfd, 0x49, contents + roff - 3); } else if (!ABI_64_P (output_bfd) && val == 0x44) { if (roff < 3) goto corrupt_input; bfd_put_8 (output_bfd, 0x41, contents + roff - 3); } bfd_put_8 (output_bfd, 0x81, contents + roff - 2); bfd_put_8 (output_bfd, 0xc0 | reg, contents + roff - 1); } else { /* addq/addl -> leaq/leal */ if (val == 0x4c) { if (roff < 3) goto corrupt_input; bfd_put_8 (output_bfd, 0x4d, contents + roff - 3); } else if (!ABI_64_P (output_bfd) && val == 0x44) { if (roff < 3) goto corrupt_input; bfd_put_8 (output_bfd, 0x45, contents + roff - 3); } bfd_put_8 (output_bfd, 0x8d, contents + roff - 2); bfd_put_8 (output_bfd, 0x80 | reg | (reg << 3), contents + roff - 1); } bfd_put_32 (output_bfd, elf_x86_64_tpoff (info, relocation), contents + roff); continue; } else if (r_type == R_X86_64_CODE_4_GOTTPOFF) { /* IE->LE transition: Originally it can be one of: mov foo@gottpoff(%rip), %reg add foo@gottpoff(%rip), %reg We change it into: mov $foo@tpoff, %reg add $foo@tpoff, %reg where reg is one of r16 to r31. */ unsigned int rex2, type, reg; unsigned int rex2_mask = REX_R | REX_R << 4; if (roff < 4) goto corrupt_input; rex2 = bfd_get_8 (input_bfd, contents + roff - 3); type = bfd_get_8 (input_bfd, contents + roff - 2); reg = bfd_get_8 (input_bfd, contents + roff - 1); reg >>= 3; /* Move the R bits to the B bits in REX2 payload byte. */ if (type == 0x8b) type = 0xc7; else type = 0x81; bfd_put_8 (output_bfd, ((rex2 & ~rex2_mask) | (rex2 & rex2_mask) >> 2), contents + roff - 3); bfd_put_8 (output_bfd, type, contents + roff - 2); bfd_put_8 (output_bfd, 0xc0 | reg, contents + roff - 1); bfd_put_32 (output_bfd, elf_x86_64_tpoff (info, relocation), contents + roff); continue; } else BFD_ASSERT (false); } if (htab->elf.sgot == NULL) abort (); if (h != NULL) { off = h->got.offset; offplt = elf_x86_hash_entry (h)->tlsdesc_got; } else { if (local_got_offsets == NULL) abort (); off = local_got_offsets[r_symndx]; offplt = local_tlsdesc_gotents[r_symndx]; } if ((off & 1) != 0) off &= ~1; else { Elf_Internal_Rela outrel; int dr_type, indx; asection *sreloc; if (htab->elf.srelgot == NULL) abort (); indx = h && h->dynindx != -1 ? h->dynindx : 0; if (GOT_TLS_GDESC_P (tls_type)) { outrel.r_info = htab->r_info (indx, R_X86_64_TLSDESC); BFD_ASSERT (htab->sgotplt_jump_table_size + offplt + 2 * GOT_ENTRY_SIZE <= htab->elf.sgotplt->size); outrel.r_offset = (htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset + offplt + htab->sgotplt_jump_table_size); sreloc = htab->elf.srelplt; if (indx == 0) outrel.r_addend = relocation - _bfd_x86_elf_dtpoff_base (info); else outrel.r_addend = 0; elf_append_rela (output_bfd, sreloc, &outrel); } sreloc = htab->elf.srelgot; outrel.r_offset = (htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off); if (GOT_TLS_GD_P (tls_type)) dr_type = R_X86_64_DTPMOD64; else if (GOT_TLS_GDESC_P (tls_type)) goto dr_done; else dr_type = R_X86_64_TPOFF64; bfd_put_64 (output_bfd, 0, htab->elf.sgot->contents + off); outrel.r_addend = 0; if ((dr_type == R_X86_64_TPOFF64 || dr_type == R_X86_64_TLSDESC) && indx == 0) outrel.r_addend = relocation - _bfd_x86_elf_dtpoff_base (info); outrel.r_info = htab->r_info (indx, dr_type); elf_append_rela (output_bfd, sreloc, &outrel); if (GOT_TLS_GD_P (tls_type)) { if (indx == 0) { BFD_ASSERT (! unresolved_reloc); bfd_put_64 (output_bfd, relocation - _bfd_x86_elf_dtpoff_base (info), htab->elf.sgot->contents + off + GOT_ENTRY_SIZE); } else { bfd_put_64 (output_bfd, 0, htab->elf.sgot->contents + off + GOT_ENTRY_SIZE); outrel.r_info = htab->r_info (indx, R_X86_64_DTPOFF64); outrel.r_offset += GOT_ENTRY_SIZE; elf_append_rela (output_bfd, sreloc, &outrel); } } dr_done: if (h != NULL) h->got.offset |= 1; else local_got_offsets[r_symndx] |= 1; } if (off >= (bfd_vma) -2 && ! GOT_TLS_GDESC_P (tls_type)) abort (); if (r_type_tls == r_type) { if (r_type == R_X86_64_GOTPC32_TLSDESC || r_type == R_X86_64_CODE_4_GOTPC32_TLSDESC || r_type == R_X86_64_TLSDESC_CALL) relocation = htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset + offplt + htab->sgotplt_jump_table_size; else relocation = htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off; unresolved_reloc = false; } else { bfd_vma roff = rel->r_offset; if (r_type == 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 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 For 32bit, change 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 For largepic, change: 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) */ int largepic = 0; if (ABI_64_P (output_bfd)) { if (contents[roff + 5] == 0xb8) { if (roff < 3 || (roff - 3 + 22) > input_section->size) goto corrupt_input; 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 { if (roff < 4 || (roff - 4 + 16) > input_section->size) goto corrupt_input; memcpy (contents + roff - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0", 16); } } else { if (roff < 3 || (roff - 3 + 15) > input_section->size) goto corrupt_input; memcpy (contents + roff - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0", 15); } relocation = (htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off - roff - largepic - input_section->output_section->vma - input_section->output_offset - 12); bfd_put_32 (output_bfd, relocation, contents + roff + 8 + largepic); /* Skip R_X86_64_PLT32/R_X86_64_PLTOFF64. */ rel++; wrel++; continue; } else if (r_type == R_X86_64_GOTPC32_TLSDESC || r_type == R_X86_64_CODE_4_GOTPC32_TLSDESC) { /* GDesc -> IE transition. It's originally something like: leaq x@tlsdesc(%rip), %rax <--- LP64 mode. rex leal x@tlsdesc(%rip), %eax <--- X32 mode. Change it to: # before xchg %ax,%ax in LP64 mode. movq x@gottpoff(%rip), %rax # before nopl (%rax) in X32 mode. rex movl x@gottpoff(%rip), %eax */ /* Now modify the instruction as appropriate. To turn a lea into a mov in the form we use it, it suffices to change the second byte from 0x8d to 0x8b. */ if (roff < 2) goto corrupt_input; bfd_put_8 (output_bfd, 0x8b, contents + roff - 2); bfd_put_32 (output_bfd, htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off - rel->r_offset - input_section->output_section->vma - input_section->output_offset - 4, contents + roff); continue; } else if (r_type == R_X86_64_TLSDESC_CALL) { /* GDesc -> IE transition. It's originally: call *(%rax) <--- LP64 mode. call *(%eax) <--- X32 mode. Change it to: xchg %ax, %ax <-- LP64 mode. nopl (%rax) <-- X32 mode. */ unsigned int prefix = 0; if (!ABI_64_P (input_bfd)) { /* Check for call *x@tlsdesc(%eax). */ if (contents[roff] == 0x67) prefix = 1; } if (prefix) { bfd_put_8 (output_bfd, 0x0f, contents + roff); bfd_put_8 (output_bfd, 0x1f, contents + roff + 1); bfd_put_8 (output_bfd, 0x00, contents + roff + 2); } else { bfd_put_8 (output_bfd, 0x66, contents + roff); bfd_put_8 (output_bfd, 0x90, contents + roff + 1); } continue; } else BFD_ASSERT (false); } break; case R_X86_64_TLSLD: 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, true)) return false; if (r_type != R_X86_64_TLSLD) { /* LD->LE transition: 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; .word 0x6666; movq %fs:0, %rax For 32bit, we change it into: 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 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)) { if ((rel->r_offset + 5) >= input_section->size) goto corrupt_input; if (contents[rel->r_offset + 5] == 0xb8) { if (rel->r_offset < 3 || (rel->r_offset - 3 + 22) > input_section->size) goto corrupt_input; 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) { if (rel->r_offset < 3 || (rel->r_offset - 3 + 13) > input_section->size) goto corrupt_input; memcpy (contents + rel->r_offset - 3, "\x66\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0", 13); } else { if (rel->r_offset < 3 || (rel->r_offset - 3 + 12) > input_section->size) goto corrupt_input; memcpy (contents + rel->r_offset - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0", 12); } } else { if ((rel->r_offset + 4) >= input_section->size) goto corrupt_input; if (contents[rel->r_offset + 4] == 0xff) { if (rel->r_offset < 3 || (rel->r_offset - 3 + 13) > input_section->size) goto corrupt_input; memcpy (contents + rel->r_offset - 3, "\x66\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0", 13); } else { if (rel->r_offset < 3 || (rel->r_offset - 3 + 12) > input_section->size) goto corrupt_input; 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; } if (htab->elf.sgot == NULL) abort (); off = htab->tls_ld_or_ldm_got.offset; if (off & 1) off &= ~1; else { Elf_Internal_Rela outrel; if (htab->elf.srelgot == NULL) abort (); outrel.r_offset = (htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off); bfd_put_64 (output_bfd, 0, htab->elf.sgot->contents + off); bfd_put_64 (output_bfd, 0, htab->elf.sgot->contents + off + GOT_ENTRY_SIZE); outrel.r_info = htab->r_info (0, R_X86_64_DTPMOD64); outrel.r_addend = 0; elf_append_rela (output_bfd, htab->elf.srelgot, &outrel); htab->tls_ld_or_ldm_got.offset |= 1; } relocation = htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + off; unresolved_reloc = false; break; case R_X86_64_DTPOFF32: if (!bfd_link_executable (info) || (input_section->flags & SEC_CODE) == 0) relocation -= _bfd_x86_elf_dtpoff_base (info); else relocation = elf_x86_64_tpoff (info, relocation); break; case R_X86_64_TPOFF32: case R_X86_64_TPOFF64: BFD_ASSERT (bfd_link_executable (info)); relocation = elf_x86_64_tpoff (info, relocation); break; case R_X86_64_DTPOFF64: BFD_ASSERT ((input_section->flags & SEC_CODE) == 0); relocation -= _bfd_x86_elf_dtpoff_base (info); break; default: break; } /* Dynamic relocs are not propagated for SEC_DEBUGGING sections because such sections are not SEC_ALLOC and thus ld.so will not process them. */ if (unresolved_reloc && !((input_section->flags & SEC_DEBUGGING) != 0 && h->def_dynamic) && _bfd_elf_section_offset (output_bfd, info, input_section, rel->r_offset) != (bfd_vma) -1) { switch (r_type) { case R_X86_64_32S: sec = h->root.u.def.section; if ((info->nocopyreloc || eh->def_protected) && !(h->root.u.def.section->flags & SEC_CODE)) return elf_x86_64_need_pic (info, input_bfd, input_section, h, NULL, NULL, howto); /* Fall through. */ default: _bfd_error_handler /* xgettext:c-format */ (_("%pB(%pA+%#" PRIx64 "): " "unresolvable %s relocation against symbol `%s'"), input_bfd, input_section, (uint64_t) rel->r_offset, howto->name, h->root.root.string); return false; } } do_relocation: r = _bfd_final_link_relocate (howto, input_bfd, input_section, contents, rel->r_offset, relocation, rel->r_addend); check_relocation_error: if (r != bfd_reloc_ok) { const char *name; if (h != NULL) name = h->root.root.string; else { name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link, sym->st_name); if (name == NULL) return false; if (*name == '\0') name = bfd_section_name (sec); } if (r == bfd_reloc_overflow) { if (converted_reloc) { info->callbacks->einfo ("%X%H:", input_bfd, input_section, rel->r_offset); info->callbacks->einfo (_(" failed to convert GOTPCREL relocation against " "'%s'; relink with --no-relax\n"), name); status = false; continue; } (*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 /* xgettext:c-format */ (_("%pB(%pA+%#" PRIx64 "): reloc against `%s': error %d"), input_bfd, input_section, (uint64_t) rel->r_offset, name, (int) r); 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 status; } /* Finish up dynamic symbol handling. We set the contents of various dynamic sections here. */ static bool elf_x86_64_finish_dynamic_symbol (bfd *output_bfd, struct bfd_link_info *info, struct elf_link_hash_entry *h, Elf_Internal_Sym *sym) { struct elf_x86_link_hash_table *htab; bool use_plt_second; struct elf_x86_link_hash_entry *eh; bool local_undefweak; htab = elf_x86_hash_table (info, X86_64_ELF_DATA); if (htab == NULL) return false; /* Use the second PLT section only if there is .plt section. */ use_plt_second = htab->elf.splt != NULL && htab->plt_second != NULL; eh = (struct elf_x86_link_hash_entry *) h; if (eh->no_finish_dynamic_symbol) abort (); /* 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); if (h->plt.offset != (bfd_vma) -1) { bfd_vma plt_index; bfd_vma got_offset, plt_offset; Elf_Internal_Rela rela; bfd_byte *loc; asection *plt, *gotplt, *relplt, *resolved_plt; const struct elf_backend_data *bed; bfd_vma plt_got_pcrel_offset; /* When building a static executable, use .iplt, .igot.plt and .rela.iplt sections for STT_GNU_IFUNC symbols. */ if (htab->elf.splt != NULL) { plt = htab->elf.splt; gotplt = htab->elf.sgotplt; relplt = htab->elf.srelplt; } else { plt = htab->elf.iplt; gotplt = htab->elf.igotplt; relplt = htab->elf.irelplt; } VERIFY_PLT_ENTRY (info, h, plt, gotplt, relplt, local_undefweak) /* Get the index in the procedure linkage table which corresponds to this symbol. This is the index of this symbol in all the symbols for which we are making plt entries. The first entry in the procedure linkage table is reserved. Get the offset into the .got table of the entry that corresponds to this function. Each .got entry is GOT_ENTRY_SIZE bytes. The first three are reserved for the dynamic linker. For static executables, we don't reserve anything. */ if (plt == htab->elf.splt) { got_offset = (h->plt.offset / htab->plt.plt_entry_size - htab->plt.has_plt0); got_offset = (got_offset + 3) * GOT_ENTRY_SIZE; } else { got_offset = h->plt.offset / htab->plt.plt_entry_size; got_offset = got_offset * GOT_ENTRY_SIZE; } /* Fill in the entry in the procedure linkage table. */ memcpy (plt->contents + h->plt.offset, htab->plt.plt_entry, htab->plt.plt_entry_size); if (use_plt_second) { memcpy (htab->plt_second->contents + eh->plt_second.offset, htab->non_lazy_plt->plt_entry, htab->non_lazy_plt->plt_entry_size); resolved_plt = htab->plt_second; plt_offset = eh->plt_second.offset; } else { resolved_plt = plt; plt_offset = h->plt.offset; } /* Insert the relocation positions of the plt section. */ /* Put offset the PC-relative instruction referring to the GOT entry, subtracting the size of that instruction. */ plt_got_pcrel_offset = (gotplt->output_section->vma + gotplt->output_offset + got_offset - resolved_plt->output_section->vma - resolved_plt->output_offset - plt_offset - htab->plt.plt_got_insn_size); /* Check PC-relative offset overflow in PLT entry. */ if ((plt_got_pcrel_offset + 0x80000000) > 0xffffffff) /* xgettext:c-format */ info->callbacks->einfo (_("%F%pB: PC-relative offset overflow in PLT entry for `%s'\n"), output_bfd, h->root.root.string); bfd_put_32 (output_bfd, plt_got_pcrel_offset, (resolved_plt->contents + plt_offset + htab->plt.plt_got_offset)); /* Fill in the entry in the global offset table, initially this 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) { if (htab->plt.has_plt0) bfd_put_64 (output_bfd, (plt->output_section->vma + plt->output_offset + h->plt.offset + htab->lazy_plt->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 (PLT_LOCAL_IFUNC_P (info, h)) { info->callbacks->minfo (_("Local IFUNC function `%s' in %pB\n"), h->root.root.string, h->root.u.def.section->owner); /* 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); if (htab->params->report_relative_reloc) _bfd_x86_elf_link_report_relative_reloc (info, relplt, h, sym, "R_X86_64_IRELATIVE", &rela); /* 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); if (htab->params->mark_plt) rela.r_addend = (resolved_plt->output_section->vma + plt_offset + htab->plt.plt_indirect_branch_offset); else rela.r_addend = 0; plt_index = htab->next_jump_slot_index++; } /* Don't fill the second and third slots in PLT entry for static executables nor without PLT0. */ if (plt == htab->elf.splt && htab->plt.has_plt0) { bfd_vma plt0_offset = h->plt.offset + htab->lazy_plt->plt_plt_insn_end; /* Put relocation index. */ bfd_put_32 (output_bfd, plt_index, (plt->contents + h->plt.offset + htab->lazy_plt->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) /* xgettext:c-format */ info->callbacks->einfo (_("%F%pB: 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 + htab->lazy_plt->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); } } else if (eh->plt_got.offset != (bfd_vma) -1) { bfd_vma got_offset, plt_offset; asection *plt, *got; bool got_after_plt; int32_t got_pcrel_offset; /* Set the entry in the GOT procedure linkage table. */ plt = htab->plt_got; got = htab->elf.sgot; got_offset = h->got.offset; if (got_offset == (bfd_vma) -1 || (h->type == STT_GNU_IFUNC && h->def_regular) || plt == NULL || got == NULL) abort (); /* Use the non-lazy PLT entry template for the GOT PLT since they are the identical. */ /* Fill in the entry in the GOT procedure linkage table. */ plt_offset = eh->plt_got.offset; memcpy (plt->contents + plt_offset, htab->non_lazy_plt->plt_entry, htab->non_lazy_plt->plt_entry_size); /* Put offset the PC-relative instruction referring to the GOT entry, subtracting the size of that instruction. */ got_pcrel_offset = (got->output_section->vma + got->output_offset + got_offset - plt->output_section->vma - plt->output_offset - plt_offset - htab->non_lazy_plt->plt_got_insn_size); /* Check PC-relative offset overflow in GOT PLT entry. */ got_after_plt = got->output_section->vma > plt->output_section->vma; if ((got_after_plt && got_pcrel_offset < 0) || (!got_after_plt && got_pcrel_offset > 0)) /* xgettext:c-format */ info->callbacks->einfo (_("%F%pB: PC-relative offset overflow in GOT PLT entry for `%s'\n"), output_bfd, h->root.root.string); bfd_put_32 (output_bfd, got_pcrel_offset, (plt->contents + plt_offset + htab->non_lazy_plt->plt_got_offset)); } if (!local_undefweak && !h->def_regular && (h->plt.offset != (bfd_vma) -1 || eh->plt_got.offset != (bfd_vma) -1)) { /* Mark the symbol as undefined, rather than as defined in the .plt section. Leave the value if there were any relocations where pointer equality matters (this is a clue for the dynamic linker, to make function pointer comparisons work between an application and shared library), otherwise set it to zero. If a function is only called from a binary, there is no need to slow down shared libraries because of that. */ sym->st_shndx = SHN_UNDEF; if (!h->pointer_equality_needed) sym->st_value = 0; } _bfd_x86_elf_link_fixup_ifunc_symbol (info, htab, h, sym); /* 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_hash_entry (h)->tls_type) && elf_x86_hash_entry (h)->tls_type != GOT_TLS_IE && !local_undefweak) { Elf_Internal_Rela rela; asection *relgot = htab->elf.srelgot; const char *relative_reloc_name = NULL; bool generate_dynamic_reloc = true; /* This symbol has an entry in the global offset table. Set it up. */ if (htab->elf.sgot == NULL || htab->elf.srelgot == NULL) abort (); rela.r_offset = (htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + (h->got.offset &~ (bfd_vma) 1)); /* If this is a static link, or it is a -Bsymbolic link and the symbol is defined locally or was forced to be local because of a version file, we just want to emit a RELATIVE reloc. The entry in the global offset table will already have been initialized in the relocate_section function. */ if (h->def_regular && h->type == STT_GNU_IFUNC) { if (h->plt.offset == (bfd_vma) -1) { /* STT_GNU_IFUNC is referenced without PLT. */ if (htab->elf.splt == NULL) { /* use .rel[a].iplt section to store .got relocations in static executable. */ relgot = htab->elf.irelplt; } if (SYMBOL_REFERENCES_LOCAL_P (info, h)) { info->callbacks->minfo (_("Local IFUNC function `%s' in %pB\n"), h->root.root.string, h->root.u.def.section->owner); 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); relative_reloc_name = "R_X86_64_IRELATIVE"; } else goto do_glob_dat; } else if (bfd_link_pic (info)) { /* Generate R_X86_64_GLOB_DAT. */ goto do_glob_dat; } else { asection *plt; bfd_vma plt_offset; if (!h->pointer_equality_needed) abort (); /* For non-shared object, we can't use .got.plt, which contains the real function addres if we need pointer equality. We load the GOT entry with the PLT entry. */ if (htab->plt_second != NULL) { plt = htab->plt_second; plt_offset = eh->plt_second.offset; } else { plt = htab->elf.splt ? htab->elf.splt : htab->elf.iplt; plt_offset = h->plt.offset; } bfd_put_64 (output_bfd, (plt->output_section->vma + plt->output_offset + plt_offset), htab->elf.sgot->contents + h->got.offset); return true; } } else if (bfd_link_pic (info) && SYMBOL_REFERENCES_LOCAL_P (info, h)) { if (!SYMBOL_DEFINED_NON_SHARED_P (h)) return false; BFD_ASSERT((h->got.offset & 1) != 0); if (info->enable_dt_relr) generate_dynamic_reloc = false; else { rela.r_info = htab->r_info (0, R_X86_64_RELATIVE); rela.r_addend = (h->root.u.def.value + h->root.u.def.section->output_section->vma + h->root.u.def.section->output_offset); relative_reloc_name = "R_X86_64_RELATIVE"; } } else { BFD_ASSERT((h->got.offset & 1) == 0); do_glob_dat: bfd_put_64 (output_bfd, (bfd_vma) 0, htab->elf.sgot->contents + h->got.offset); rela.r_info = htab->r_info (h->dynindx, R_X86_64_GLOB_DAT); rela.r_addend = 0; } if (generate_dynamic_reloc) { if (relative_reloc_name != NULL && htab->params->report_relative_reloc) _bfd_x86_elf_link_report_relative_reloc (info, relgot, h, sym, relative_reloc_name, &rela); elf_append_rela (output_bfd, relgot, &rela); } } if (h->needs_copy) { Elf_Internal_Rela rela; asection *s; /* This symbol needs a copy reloc. Set it up. */ VERIFY_COPY_RELOC (h, htab) rela.r_offset = (h->root.u.def.value + h->root.u.def.section->output_section->vma + h->root.u.def.section->output_offset); rela.r_info = htab->r_info (h->dynindx, R_X86_64_COPY); rela.r_addend = 0; if (h->root.u.def.section == htab->elf.sdynrelro) s = htab->elf.sreldynrelro; else s = htab->elf.srelbss; elf_append_rela (output_bfd, s, &rela); } return true; } /* Finish up local dynamic symbol handling. We set the contents of various dynamic sections here. */ static int elf_x86_64_finish_local_dynamic_symbol (void **slot, void *inf) { struct elf_link_hash_entry *h = (struct elf_link_hash_entry *) *slot; struct bfd_link_info *info = (struct bfd_link_info *) inf; return elf_x86_64_finish_dynamic_symbol (info->output_bfd, 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 bool 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, 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_link_hash_table *htab = elf_x86_hash_table (info, X86_64_ELF_DATA); 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); if (r_symndx != STN_UNDEF) { 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_IRELATIVE: return reloc_class_ifunc; case R_X86_64_RELATIVE: case R_X86_64_RELATIVE64: return reloc_class_relative; case R_X86_64_JUMP_SLOT: return reloc_class_plt; case R_X86_64_COPY: return reloc_class_copy; default: return reloc_class_normal; } } /* Finish up the dynamic sections. */ static bool elf_x86_64_finish_dynamic_sections (bfd *output_bfd, struct bfd_link_info *info) { struct elf_x86_link_hash_table *htab; htab = _bfd_x86_elf_finish_dynamic_sections (output_bfd, info); if (htab == NULL) return false; if (! htab->elf.dynamic_sections_created) return true; if (htab->elf.splt && htab->elf.splt->size > 0) { if (bfd_is_abs_section (htab->elf.splt->output_section)) { info->callbacks->einfo (_("%F%P: discarded output section: `%pA'\n"), htab->elf.splt); return false; } elf_section_data (htab->elf.splt->output_section) ->this_hdr.sh_entsize = htab->plt.plt_entry_size; if (htab->plt.has_plt0) { /* Fill in the special first entry in the procedure linkage table. */ memcpy (htab->elf.splt->contents, htab->lazy_plt->plt0_entry, htab->lazy_plt->plt0_entry_size); /* Add offset for pushq GOT+8(%rip), since the instruction uses 6 bytes subtract this value. */ bfd_put_32 (output_bfd, (htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset + 8 - htab->elf.splt->output_section->vma - htab->elf.splt->output_offset - 6), (htab->elf.splt->contents + htab->lazy_plt->plt0_got1_offset)); /* Add offset for the PC-relative instruction accessing GOT+16, subtracting the offset to the end of that instruction. */ bfd_put_32 (output_bfd, (htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset + 16 - htab->elf.splt->output_section->vma - htab->elf.splt->output_offset - htab->lazy_plt->plt0_got2_insn_end), (htab->elf.splt->contents + htab->lazy_plt->plt0_got2_offset)); } if (htab->elf.tlsdesc_plt) { bfd_put_64 (output_bfd, (bfd_vma) 0, htab->elf.sgot->contents + htab->elf.tlsdesc_got); memcpy (htab->elf.splt->contents + htab->elf.tlsdesc_plt, htab->lazy_plt->plt_tlsdesc_entry, htab->lazy_plt->plt_tlsdesc_entry_size); /* Add offset for pushq GOT+8(%rip), since ENDBR64 uses 4 bytes and the instruction uses 6 bytes, subtract these values. */ bfd_put_32 (output_bfd, (htab->elf.sgotplt->output_section->vma + htab->elf.sgotplt->output_offset + 8 - htab->elf.splt->output_section->vma - htab->elf.splt->output_offset - htab->elf.tlsdesc_plt - htab->lazy_plt->plt_tlsdesc_got1_insn_end), (htab->elf.splt->contents + htab->elf.tlsdesc_plt + htab->lazy_plt->plt_tlsdesc_got1_offset)); /* Add offset for indirect branch via GOT+TDG, where TDG stands for htab->tlsdesc_got, subtracting the offset to the end of that instruction. */ bfd_put_32 (output_bfd, (htab->elf.sgot->output_section->vma + htab->elf.sgot->output_offset + htab->elf.tlsdesc_got - htab->elf.splt->output_section->vma - htab->elf.splt->output_offset - htab->elf.tlsdesc_plt - htab->lazy_plt->plt_tlsdesc_got2_insn_end), (htab->elf.splt->contents + htab->elf.tlsdesc_plt + htab->lazy_plt->plt_tlsdesc_got2_offset)); } } /* 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; } /* Fill PLT/GOT entries and allocate dynamic relocations for local STT_GNU_IFUNC symbols, which aren't in the ELF linker hash table. It has to be done before elf_link_sort_relocs is called so that dynamic relocations are properly sorted. */ static bool elf_x86_64_output_arch_local_syms (bfd *output_bfd ATTRIBUTE_UNUSED, struct bfd_link_info *info, void *flaginfo ATTRIBUTE_UNUSED, int (*func) (void *, const char *, Elf_Internal_Sym *, asection *, struct elf_link_hash_entry *) ATTRIBUTE_UNUSED) { struct elf_x86_link_hash_table *htab = elf_x86_hash_table (info, X86_64_ELF_DATA); if (htab == NULL) return false; /* Fill PLT and GOT entries for local STT_GNU_IFUNC symbols. */ htab_traverse (htab->loc_hash_table, elf_x86_64_finish_local_dynamic_symbol, info); return true; } /* Similar to _bfd_elf_get_synthetic_symtab. Support PLTs with all dynamic relocations. */ static long elf_x86_64_get_synthetic_symtab (bfd *abfd, long symcount ATTRIBUTE_UNUSED, asymbol **syms ATTRIBUTE_UNUSED, long dynsymcount, asymbol **dynsyms, asymbol **ret) { long count, i, n; int j; bfd_byte *plt_contents; long relsize; const struct elf_x86_lazy_plt_layout *lazy_plt; const struct elf_x86_non_lazy_plt_layout *non_lazy_plt; const struct elf_x86_lazy_plt_layout *lazy_bnd_plt; const struct elf_x86_non_lazy_plt_layout *non_lazy_bnd_plt; const struct elf_x86_lazy_plt_layout *lazy_ibt_plt; const struct elf_x86_non_lazy_plt_layout *non_lazy_ibt_plt; const struct elf_x86_lazy_plt_layout *x32_lazy_ibt_plt; const struct elf_x86_non_lazy_plt_layout *x32_non_lazy_ibt_plt; asection *plt; enum elf_x86_plt_type plt_type; struct elf_x86_plt plts[] = { { ".plt", NULL, NULL, plt_unknown, 0, 0, 0, 0 }, { ".plt.got", NULL, NULL, plt_non_lazy, 0, 0, 0, 0 }, { ".plt.sec", NULL, NULL, plt_second, 0, 0, 0, 0 }, { ".plt.bnd", NULL, NULL, plt_second, 0, 0, 0, 0 }, { NULL, NULL, NULL, plt_non_lazy, 0, 0, 0, 0 } }; *ret = NULL; if ((abfd->flags & (DYNAMIC | EXEC_P)) == 0) return 0; if (dynsymcount <= 0) return 0; relsize = bfd_get_dynamic_reloc_upper_bound (abfd); if (relsize <= 0) return -1; lazy_plt = &elf_x86_64_lazy_plt; non_lazy_plt = &elf_x86_64_non_lazy_plt; lazy_bnd_plt = &elf_x86_64_lazy_bnd_plt; non_lazy_bnd_plt = &elf_x86_64_non_lazy_bnd_plt; if (ABI_64_P (abfd)) { lazy_ibt_plt = &elf_x86_64_lazy_ibt_plt; non_lazy_ibt_plt = &elf_x86_64_non_lazy_ibt_plt; x32_lazy_ibt_plt = &elf_x32_lazy_ibt_plt; x32_non_lazy_ibt_plt = &elf_x32_non_lazy_ibt_plt; } else { lazy_ibt_plt = &elf_x32_lazy_ibt_plt; non_lazy_ibt_plt = &elf_x32_non_lazy_ibt_plt; x32_lazy_ibt_plt = NULL; x32_non_lazy_ibt_plt = NULL; } count = 0; for (j = 0; plts[j].name != NULL; j++) { plt = bfd_get_section_by_name (abfd, plts[j].name); if (plt == NULL || plt->size == 0 || (plt->flags & SEC_HAS_CONTENTS) == 0) continue; /* Get the PLT section contents. */ if (!bfd_malloc_and_get_section (abfd, plt, &plt_contents)) break; /* Check what kind of PLT it is. */ plt_type = plt_unknown; if (plts[j].type == plt_unknown && (plt->size >= (lazy_plt->plt_entry_size + lazy_plt->plt_entry_size))) { /* Match lazy PLT first. Need to check the first two instructions. */ if ((memcmp (plt_contents, lazy_plt->plt0_entry, lazy_plt->plt0_got1_offset) == 0) && (memcmp (plt_contents + 6, lazy_plt->plt0_entry + 6, 2) == 0)) { if (x32_lazy_ibt_plt != NULL && (memcmp (plt_contents + x32_lazy_ibt_plt->plt_entry_size, x32_lazy_ibt_plt->plt_entry, x32_lazy_ibt_plt->plt_got_offset) == 0)) { /* The fist entry in the x32 lazy IBT PLT is the same as the lazy PLT. */ plt_type = plt_lazy | plt_second; lazy_plt = x32_lazy_ibt_plt; } else plt_type = plt_lazy; } else if (lazy_bnd_plt != NULL && (memcmp (plt_contents, lazy_bnd_plt->plt0_entry, lazy_bnd_plt->plt0_got1_offset) == 0) && (memcmp (plt_contents + 6, lazy_bnd_plt->plt0_entry + 6, 3) == 0)) { plt_type = plt_lazy | plt_second; /* The fist entry in the lazy IBT PLT is the same as the lazy BND PLT. */ if ((memcmp (plt_contents + lazy_ibt_plt->plt_entry_size, lazy_ibt_plt->plt_entry, lazy_ibt_plt->plt_got_offset) == 0)) lazy_plt = lazy_ibt_plt; else lazy_plt = lazy_bnd_plt; } } if (non_lazy_plt != NULL && (plt_type == plt_unknown || plt_type == plt_non_lazy) && plt->size >= non_lazy_plt->plt_entry_size) { /* Match non-lazy PLT. */ if (memcmp (plt_contents, non_lazy_plt->plt_entry, non_lazy_plt->plt_got_offset) == 0) plt_type = plt_non_lazy; } if (plt_type == plt_unknown || plt_type == plt_second) { if (non_lazy_bnd_plt != NULL && plt->size >= non_lazy_bnd_plt->plt_entry_size && (memcmp (plt_contents, non_lazy_bnd_plt->plt_entry, non_lazy_bnd_plt->plt_got_offset) == 0)) { /* Match BND PLT. */ plt_type = plt_second; non_lazy_plt = non_lazy_bnd_plt; } else if (non_lazy_ibt_plt != NULL && plt->size >= non_lazy_ibt_plt->plt_entry_size && (memcmp (plt_contents, non_lazy_ibt_plt->plt_entry, non_lazy_ibt_plt->plt_got_offset) == 0)) { /* Match IBT PLT. */ plt_type = plt_second; non_lazy_plt = non_lazy_ibt_plt; } else if (x32_non_lazy_ibt_plt != NULL && plt->size >= x32_non_lazy_ibt_plt->plt_entry_size && (memcmp (plt_contents, x32_non_lazy_ibt_plt->plt_entry, x32_non_lazy_ibt_plt->plt_got_offset) == 0)) { /* Match x32 IBT PLT. */ plt_type = plt_second; non_lazy_plt = x32_non_lazy_ibt_plt; } } if (plt_type == plt_unknown) { free (plt_contents); continue; } plts[j].sec = plt; plts[j].type = plt_type; if ((plt_type & plt_lazy)) { plts[j].plt_got_offset = lazy_plt->plt_got_offset; plts[j].plt_got_insn_size = lazy_plt->plt_got_insn_size; plts[j].plt_entry_size = lazy_plt->plt_entry_size; /* Skip PLT0 in lazy PLT. */ i = 1; } else { plts[j].plt_got_offset = non_lazy_plt->plt_got_offset; plts[j].plt_got_insn_size = non_lazy_plt->plt_got_insn_size; plts[j].plt_entry_size = non_lazy_plt->plt_entry_size; i = 0; } /* Skip lazy PLT when the second PLT is used. */ if (plt_type == (plt_lazy | plt_second)) plts[j].count = 0; else { n = plt->size / plts[j].plt_entry_size; plts[j].count = n; count += n - i; } plts[j].contents = plt_contents; } return _bfd_x86_elf_get_synthetic_symtab (abfd, count, relsize, (bfd_vma) 0, plts, dynsyms, ret); } /* Handle an x86-64 specific section when reading an object file. This is called when elfcode.h finds a section with an unknown type. */ static bool elf_x86_64_section_from_shdr (bfd *abfd, Elf_Internal_Shdr *hdr, const char *name, int shindex) { if (hdr->sh_type != SHT_X86_64_UNWIND) return false; if (! _bfd_elf_make_section_from_shdr (abfd, hdr, name, shindex)) return false; return true; } /* Hook called by the linker routine which adds symbols from an object file. We use it to put SHN_X86_64_LCOMMON items in .lbss, instead of .bss. */ static bool elf_x86_64_add_symbol_hook (bfd *abfd, struct bfd_link_info *info ATTRIBUTE_UNUSED, Elf_Internal_Sym *sym, const char **namep ATTRIBUTE_UNUSED, flagword *flagsp ATTRIBUTE_UNUSED, asection **secp, bfd_vma *valp) { asection *lcomm; switch (sym->st_shndx) { case SHN_X86_64_LCOMMON: lcomm = bfd_get_section_by_name (abfd, "LARGE_COMMON"); if (lcomm == NULL) { lcomm = bfd_make_section_with_flags (abfd, "LARGE_COMMON", (SEC_ALLOC | SEC_IS_COMMON | SEC_LINKER_CREATED)); if (lcomm == NULL) return false; elf_section_flags (lcomm) |= SHF_X86_64_LARGE; } *secp = lcomm; *valp = sym->st_size; return true; } return true; } /* Given a BFD section, try to locate the corresponding ELF section index. */ static bool elf_x86_64_elf_section_from_bfd_section (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, int *index_return) { if (sec == &_bfd_elf_large_com_section) { *index_return = SHN_X86_64_LCOMMON; return true; } return false; } /* Process a symbol. */ static void elf_x86_64_symbol_processing (bfd *abfd ATTRIBUTE_UNUSED, asymbol *asym) { elf_symbol_type *elfsym = (elf_symbol_type *) asym; switch (elfsym->internal_elf_sym.st_shndx) { case SHN_X86_64_LCOMMON: asym->section = &_bfd_elf_large_com_section; asym->value = elfsym->internal_elf_sym.st_size; /* Common symbol doesn't set BSF_GLOBAL. */ asym->flags &= ~BSF_GLOBAL; break; } } static bool elf_x86_64_common_definition (Elf_Internal_Sym *sym) { return (sym->st_shndx == SHN_COMMON || sym->st_shndx == SHN_X86_64_LCOMMON); } static unsigned int elf_x86_64_common_section_index (asection *sec) { if ((elf_section_flags (sec) & SHF_X86_64_LARGE) == 0) return SHN_COMMON; else return SHN_X86_64_LCOMMON; } static asection * elf_x86_64_common_section (asection *sec) { if ((elf_section_flags (sec) & SHF_X86_64_LARGE) == 0) return bfd_com_section_ptr; else return &_bfd_elf_large_com_section; } static bool elf_x86_64_merge_symbol (struct elf_link_hash_entry *h, const Elf_Internal_Sym *sym, asection **psec, bool newdef, bool olddef, bfd *oldbfd, const asection *oldsec) { /* A normal common symbol and a large common symbol result in a normal common symbol. We turn the large common symbol into a normal one. */ if (!olddef && h->root.type == bfd_link_hash_common && !newdef && bfd_is_com_section (*psec) && oldsec != *psec) { if (sym->st_shndx == SHN_COMMON && (elf_section_flags (oldsec) & SHF_X86_64_LARGE) != 0) { h->root.u.c.p->section = bfd_make_section_old_way (oldbfd, "COMMON"); h->root.u.c.p->section->flags = SEC_ALLOC; } else if (sym->st_shndx == SHN_X86_64_LCOMMON && (elf_section_flags (oldsec) & SHF_X86_64_LARGE) == 0) *psec = bfd_com_section_ptr; } return true; } static bool elf_x86_64_section_flags (const Elf_Internal_Shdr *hdr) { if ((hdr->sh_flags & SHF_X86_64_LARGE) != 0) hdr->bfd_section->flags |= SEC_ELF_LARGE; return true; } static bool elf_x86_64_fake_sections (bfd *abfd ATTRIBUTE_UNUSED, Elf_Internal_Shdr *hdr, asection *sec) { if (sec->flags & SEC_ELF_LARGE) hdr->sh_flags |= SHF_X86_64_LARGE; return true; } static bool elf_x86_64_copy_private_section_data (bfd *ibfd, asection *isec, bfd *obfd, asection *osec) { if (!_bfd_elf_copy_private_section_data (ibfd, isec, obfd, osec)) return false; /* objcopy --set-section-flags without "large" drops SHF_X86_64_LARGE. */ if (ibfd != obfd) elf_section_flags (osec) &= ~SHF_X86_64_LARGE; return true; } static int elf_x86_64_additional_program_headers (bfd *abfd, struct bfd_link_info *info ATTRIBUTE_UNUSED) { asection *s; int count = 0; /* Check to see if we need a large readonly segment. */ s = bfd_get_section_by_name (abfd, ".lrodata"); if (s && (s->flags & SEC_LOAD)) count++; /* Check to see if we need a large data segment. Since .lbss sections is placed right after the .bss section, there should be no need for a large data segment just because of .lbss. */ s = bfd_get_section_by_name (abfd, ".ldata"); if (s && (s->flags & SEC_LOAD)) count++; return count; } /* Return TRUE iff relocations for INPUT are compatible with OUTPUT. */ static bool elf_x86_64_relocs_compatible (const bfd_target *input, const bfd_target *output) { return ((xvec_get_elf_backend_data (input)->s->elfclass == xvec_get_elf_backend_data (output)->s->elfclass) && _bfd_elf_relocs_compatible (input, output)); } /* Set up x86-64 GNU properties. Return the first relocatable ELF input with GNU properties if found. Otherwise, return NULL. */ static bfd * elf_x86_64_link_setup_gnu_properties (struct bfd_link_info *info) { struct elf_x86_init_table init_table; const struct elf_backend_data *bed; struct elf_x86_link_hash_table *htab; if ((int) R_X86_64_standard >= (int) R_X86_64_converted_reloc_bit || (int) R_X86_64_max <= (int) R_X86_64_converted_reloc_bit || ((int) (R_X86_64_GNU_VTINHERIT | R_X86_64_converted_reloc_bit) != (int) R_X86_64_GNU_VTINHERIT) || ((int) (R_X86_64_GNU_VTENTRY | R_X86_64_converted_reloc_bit) != (int) R_X86_64_GNU_VTENTRY)) abort (); /* This is unused for x86-64. */ init_table.plt0_pad_byte = 0x90; bed = get_elf_backend_data (info->output_bfd); htab = elf_x86_hash_table (info, bed->target_id); if (!htab) abort (); init_table.lazy_plt = &elf_x86_64_lazy_plt; init_table.non_lazy_plt = &elf_x86_64_non_lazy_plt; init_table.lazy_ibt_plt = &elf_x32_lazy_ibt_plt; init_table.non_lazy_ibt_plt = &elf_x32_non_lazy_ibt_plt; if (ABI_64_P (info->output_bfd)) { init_table.sframe_lazy_plt = &elf_x86_64_sframe_plt; init_table.sframe_non_lazy_plt = &elf_x86_64_sframe_non_lazy_plt; init_table.sframe_lazy_ibt_plt = &elf_x86_64_sframe_plt; init_table.sframe_non_lazy_ibt_plt = &elf_x86_64_sframe_non_lazy_plt; } else { /* SFrame is not supported for non AMD64. */ init_table.sframe_lazy_plt = NULL; init_table.sframe_non_lazy_plt = NULL; } if (ABI_64_P (info->output_bfd)) { init_table.r_info = elf64_r_info; init_table.r_sym = elf64_r_sym; } else { init_table.r_info = elf32_r_info; init_table.r_sym = elf32_r_sym; } return _bfd_x86_elf_link_setup_gnu_properties (info, &init_table); } static const struct bfd_elf_special_section elf_x86_64_special_sections[]= { { STRING_COMMA_LEN (".gnu.linkonce.lb"), -2, SHT_NOBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE}, { STRING_COMMA_LEN (".gnu.linkonce.lr"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_X86_64_LARGE}, { STRING_COMMA_LEN (".gnu.linkonce.lt"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR + SHF_X86_64_LARGE}, { STRING_COMMA_LEN (".lbss"), -2, SHT_NOBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE}, { STRING_COMMA_LEN (".ldata"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_WRITE + SHF_X86_64_LARGE}, { STRING_COMMA_LEN (".lrodata"), -2, SHT_PROGBITS, SHF_ALLOC + SHF_X86_64_LARGE}, { NULL, 0, 0, 0, 0 } }; #define TARGET_LITTLE_SYM x86_64_elf64_vec #define TARGET_LITTLE_NAME "elf64-x86-64" #define ELF_ARCH bfd_arch_i386 #define ELF_TARGET_ID X86_64_ELF_DATA #define ELF_MACHINE_CODE EM_X86_64 #define ELF_MAXPAGESIZE 0x1000 #define ELF_COMMONPAGESIZE 0x1000 #define elf_backend_can_gc_sections 1 #define elf_backend_can_refcount 1 #define elf_backend_want_got_plt 1 #define elf_backend_plt_readonly 1 #define elf_backend_want_plt_sym 0 #define elf_backend_got_header_size (GOT_ENTRY_SIZE*3) #define elf_backend_rela_normal 1 #define elf_backend_plt_alignment 4 #define elf_backend_caches_rawsize 1 #define elf_backend_dtrel_excludes_plt 1 #define elf_backend_want_dynrelro 1 #define elf_info_to_howto elf_x86_64_info_to_howto #define bfd_elf64_bfd_copy_private_section_data \ elf_x86_64_copy_private_section_data #define bfd_elf64_bfd_reloc_type_lookup elf_x86_64_reloc_type_lookup #define bfd_elf64_bfd_reloc_name_lookup \ elf_x86_64_reloc_name_lookup #define elf_backend_relocs_compatible elf_x86_64_relocs_compatible #define elf_backend_always_size_sections elf_x86_64_always_size_sections #define elf_backend_create_dynamic_sections _bfd_elf_create_dynamic_sections #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_output_arch_local_syms elf_x86_64_output_arch_local_syms #define elf_backend_grok_prstatus elf_x86_64_grok_prstatus #define elf_backend_grok_psinfo elf_x86_64_grok_psinfo #ifdef CORE_HEADER #define elf_backend_write_core_note elf_x86_64_write_core_note #endif #define elf_backend_reloc_type_class elf_x86_64_reloc_type_class #define elf_backend_relocate_section elf_x86_64_relocate_section #define elf_backend_init_index_section _bfd_elf_init_1_index_section #define elf_backend_object_p elf64_x86_64_elf_object_p #define bfd_elf64_get_synthetic_symtab elf_x86_64_get_synthetic_symtab #define elf_backend_section_from_shdr \ elf_x86_64_section_from_shdr #define elf_backend_section_from_bfd_section \ elf_x86_64_elf_section_from_bfd_section #define elf_backend_add_symbol_hook \ elf_x86_64_add_symbol_hook #define elf_backend_symbol_processing \ elf_x86_64_symbol_processing #define elf_backend_common_section_index \ elf_x86_64_common_section_index #define elf_backend_common_section \ elf_x86_64_common_section #define elf_backend_common_definition \ elf_x86_64_common_definition #define elf_backend_merge_symbol \ elf_x86_64_merge_symbol #define elf_backend_special_sections \ elf_x86_64_special_sections #define elf_backend_section_flags elf_x86_64_section_flags #define elf_backend_fake_sections elf_x86_64_fake_sections #define elf_backend_additional_program_headers \ elf_x86_64_additional_program_headers #define elf_backend_setup_gnu_properties \ elf_x86_64_link_setup_gnu_properties #define elf_backend_hide_symbol \ _bfd_x86_elf_hide_symbol #undef elf64_bed #define elf64_bed elf64_x86_64_bed #include "elf64-target.h" /* CloudABI support. */ #undef TARGET_LITTLE_SYM #define TARGET_LITTLE_SYM x86_64_elf64_cloudabi_vec #undef TARGET_LITTLE_NAME #define TARGET_LITTLE_NAME "elf64-x86-64-cloudabi" #undef ELF_OSABI #define ELF_OSABI ELFOSABI_CLOUDABI #undef elf64_bed #define elf64_bed elf64_x86_64_cloudabi_bed #include "elf64-target.h" /* FreeBSD support. */ #undef TARGET_LITTLE_SYM #define TARGET_LITTLE_SYM x86_64_elf64_fbsd_vec #undef TARGET_LITTLE_NAME #define TARGET_LITTLE_NAME "elf64-x86-64-freebsd" #undef ELF_OSABI #define ELF_OSABI ELFOSABI_FREEBSD #undef elf64_bed #define elf64_bed elf64_x86_64_fbsd_bed #include "elf64-target.h" /* Solaris 2 support. */ #undef TARGET_LITTLE_SYM #define TARGET_LITTLE_SYM x86_64_elf64_sol2_vec #undef TARGET_LITTLE_NAME #define TARGET_LITTLE_NAME "elf64-x86-64-sol2" #undef ELF_TARGET_OS #define ELF_TARGET_OS is_solaris /* Restore default: we cannot use ELFOSABI_SOLARIS, otherwise ELFOSABI_NONE objects won't be recognized. */ #undef ELF_OSABI #undef elf64_bed #define elf64_bed elf64_x86_64_sol2_bed /* The 64-bit static TLS arena size is rounded to the nearest 16-byte boundary. */ #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 #define elf_backend_want_plt_sym 1 #undef elf_backend_strtab_flags #define elf_backend_strtab_flags SHF_STRINGS static bool 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" /* Restore defaults. */ #undef ELF_OSABI #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 /* 32bit x86-64 support. */ #undef TARGET_LITTLE_SYM #define TARGET_LITTLE_SYM x86_64_elf32_vec #undef TARGET_LITTLE_NAME #define TARGET_LITTLE_NAME "elf32-x86-64" #undef elf32_bed #define elf32_bed elf32_x86_64_bed #undef ELF_ARCH #define ELF_ARCH bfd_arch_i386 #undef ELF_MACHINE_CODE #define ELF_MACHINE_CODE EM_X86_64 #undef ELF_TARGET_OS #undef ELF_OSABI #define bfd_elf32_bfd_copy_private_section_data \ elf_x86_64_copy_private_section_data #define bfd_elf32_bfd_reloc_type_lookup \ elf_x86_64_reloc_type_lookup #define bfd_elf32_bfd_reloc_name_lookup \ elf_x86_64_reloc_name_lookup #define bfd_elf32_get_synthetic_symtab \ elf_x86_64_get_synthetic_symtab #undef elf_backend_object_p #define elf_backend_object_p \ elf32_x86_64_elf_object_p #undef elf_backend_bfd_from_remote_memory #define elf_backend_bfd_from_remote_memory \ _bfd_elf32_bfd_from_remote_memory #undef elf_backend_size_info #define elf_backend_size_info \ _bfd_elf32_size_info #include "elf32-target.h"