| /* Return build ID information for a module. |
| Copyright (C) 2007-2010 Red Hat, Inc. |
| This file is part of elfutils. |
| |
| This file is free software; you can redistribute it and/or modify |
| it under the terms of either |
| |
| * the GNU Lesser General Public License as published by the Free |
| Software Foundation; either version 3 of the License, or (at |
| your option) any later version |
| |
| or |
| |
| * the GNU General Public License as published by the Free |
| Software Foundation; either version 2 of the License, or (at |
| your option) any later version |
| |
| or both in parallel, as here. |
| |
| elfutils 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 copies of the GNU General Public License and |
| the GNU Lesser General Public License along with this program. If |
| not, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "libdwflP.h" |
| |
| static int |
| found_build_id (Dwfl_Module *mod, bool set, |
| const void *bits, int len, GElf_Addr vaddr) |
| { |
| if (!set) |
| /* When checking bits, we do not compare VADDR because the |
| address found in a debuginfo file may not match the main |
| file as modified by prelink. */ |
| return 1 + (mod->build_id_len == len |
| && !memcmp (bits, mod->build_id_bits, len)); |
| |
| void *copy = malloc (len); |
| if (unlikely (copy == NULL)) |
| { |
| __libdwfl_seterrno (DWFL_E_NOMEM); |
| return -1; |
| } |
| |
| mod->build_id_bits = memcpy (copy, bits, len); |
| mod->build_id_vaddr = vaddr; |
| mod->build_id_len = len; |
| return len; |
| } |
| |
| #define NO_VADDR ((GElf_Addr) -1l) |
| |
| static int |
| check_notes (Dwfl_Module *mod, bool set, Elf_Data *data, GElf_Addr data_vaddr) |
| { |
| size_t pos = 0; |
| GElf_Nhdr nhdr; |
| size_t name_pos; |
| size_t desc_pos; |
| while ((pos = gelf_getnote (data, pos, &nhdr, &name_pos, &desc_pos)) > 0) |
| if (nhdr.n_type == NT_GNU_BUILD_ID |
| && nhdr.n_namesz == sizeof "GNU" && !memcmp (data->d_buf + name_pos, |
| "GNU", sizeof "GNU")) |
| return found_build_id (mod, set, |
| data->d_buf + desc_pos, nhdr.n_descsz, |
| data_vaddr == NO_VADDR ? 0 |
| : data_vaddr + desc_pos); |
| return 0; |
| } |
| |
| int |
| internal_function |
| __libdwfl_find_build_id (Dwfl_Module *mod, bool set, Elf *elf) |
| { |
| size_t shstrndx = SHN_UNDEF; |
| int result = 0; |
| |
| Elf_Scn *scn = elf_nextscn (elf, NULL); |
| |
| if (scn == NULL) |
| { |
| /* No sections, have to look for phdrs. */ |
| GElf_Ehdr ehdr_mem; |
| GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem); |
| size_t phnum; |
| if (unlikely (ehdr == NULL) |
| || unlikely (elf_getphdrnum (elf, &phnum) != 0)) |
| { |
| __libdwfl_seterrno (DWFL_E_LIBELF); |
| return -1; |
| } |
| for (size_t i = 0; result == 0 && i < phnum; ++i) |
| { |
| GElf_Phdr phdr_mem; |
| GElf_Phdr *phdr = gelf_getphdr (elf, i, &phdr_mem); |
| if (likely (phdr != NULL) && phdr->p_type == PT_NOTE) |
| result = check_notes (mod, set, |
| elf_getdata_rawchunk (elf, |
| phdr->p_offset, |
| phdr->p_filesz, |
| ELF_T_NHDR), |
| dwfl_adjusted_address (mod, phdr->p_vaddr)); |
| } |
| } |
| else |
| do |
| { |
| GElf_Shdr shdr_mem; |
| GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); |
| if (likely (shdr != NULL) && shdr->sh_type == SHT_NOTE) |
| { |
| /* Determine the right sh_addr in this module. */ |
| GElf_Addr vaddr = 0; |
| if (!(shdr->sh_flags & SHF_ALLOC)) |
| vaddr = NO_VADDR; |
| else if (mod->e_type != ET_REL) |
| vaddr = dwfl_adjusted_address (mod, shdr->sh_addr); |
| else if (__libdwfl_relocate_value (mod, elf, &shstrndx, |
| elf_ndxscn (scn), &vaddr)) |
| vaddr = NO_VADDR; |
| result = check_notes (mod, set, elf_getdata (scn, NULL), vaddr); |
| } |
| } |
| while (result == 0 && (scn = elf_nextscn (elf, scn)) != NULL); |
| |
| return result; |
| } |
| |
| int |
| dwfl_module_build_id (Dwfl_Module *mod, |
| const unsigned char **bits, GElf_Addr *vaddr) |
| { |
| if (mod == NULL) |
| return -1; |
| |
| if (mod->build_id_len == 0 && mod->main.elf != NULL) |
| { |
| /* We have the file, but have not examined it yet. */ |
| int result = __libdwfl_find_build_id (mod, true, mod->main.elf); |
| if (result <= 0) |
| { |
| mod->build_id_len = -1; /* Cache negative result. */ |
| return result; |
| } |
| } |
| |
| if (mod->build_id_len <= 0) |
| return 0; |
| |
| *bits = mod->build_id_bits; |
| *vaddr = mod->build_id_vaddr; |
| return mod->build_id_len; |
| } |
| INTDEF (dwfl_module_build_id) |
| NEW_VERSION (dwfl_module_build_id, ELFUTILS_0.138) |
| |
| #ifdef SHARED |
| COMPAT_VERSION (dwfl_module_build_id, ELFUTILS_0.130, vaddr_at_end) |
| |
| int |
| _compat_vaddr_at_end_dwfl_module_build_id (Dwfl_Module *mod, |
| const unsigned char **bits, |
| GElf_Addr *vaddr) |
| { |
| int result = INTUSE(dwfl_module_build_id) (mod, bits, vaddr); |
| if (result > 0) |
| *vaddr += (result + 3) & -4; |
| return result; |
| } |
| #endif |