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abg-elf-helpers: move some versioning helpers from abg-dwarf-reader
Move some definitions from abg-dwarf-reader to abg-elf-helpers that are strictly only related to ELF. * abg-dwarf-reader.cc (get_symbol_versionning_sections): Move function out. (get_version_definition_for_versym): Likewise. (get_version_needed_for_versym): Likewise. (get_version_for_symbol): Likewise. * abg-elf-helpers.cc (get_symbol_versionning_sections): Move function in. (get_version_definition_for_versym): Likewise. (get_version_needed_for_versym): Likewise. (get_version_for_symbol): Likewise. * abg-elf-helpers.h (get_symbol_versionning_sections): Add declaration. (get_version_definition_for_versym): Likewise. (get_version_needed_for_versym): Likewise. (get_version_for_symbol): Likewise. Reviewed-by: Giuliano Procida <gprocida@google.com> Signed-off-by: Matthias Maennich <maennich@google.com> Signed-off-by: Dodji Seketeli <dodji@redhat.com>
This commit is contained in:
Matthias Maennich
Dodji Seketeli
parent
ee83a9e17a
commit
9815efe7a5
@ -293,12 +293,6 @@ static void
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add_symbol_to_map(const elf_symbol_sptr& sym,
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string_elf_symbols_map_type& map);
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static bool
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get_symbol_versionning_sections(Elf* elf_handle,
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Elf_Scn*& versym_section,
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Elf_Scn*& verdef_section,
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Elf_Scn*& verneed_section);
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static bool
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get_parent_die(const read_context& ctxt,
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const Dwarf_Die* die,
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@ -866,256 +860,6 @@ compare_symbol_name(const string& symbol_name,
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return symbol_name == name;
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}
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/// Return the SHT_GNU_versym, SHT_GNU_verdef and SHT_GNU_verneed
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/// sections that are involved in symbol versionning.
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///
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/// @param elf_handle the elf handle to use.
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///
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/// @param versym_section the SHT_GNU_versym section found. If the
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/// section wasn't found, this is set to nil.
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///
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/// @param verdef_section the SHT_GNU_verdef section found. If the
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/// section wasn't found, this is set to nil.
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///
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/// @param verneed_section the SHT_GNU_verneed section found. If the
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/// section wasn't found, this is set to nil.
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///
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/// @return true iff at least one of the sections where found.
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static bool
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get_symbol_versionning_sections(Elf* elf_handle,
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Elf_Scn*& versym_section,
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Elf_Scn*& verdef_section,
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Elf_Scn*& verneed_section)
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{
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Elf_Scn* section = NULL;
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GElf_Shdr mem;
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Elf_Scn* versym = NULL, *verdef = NULL, *verneed = NULL;
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while ((section = elf_nextscn(elf_handle, section)) != NULL)
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{
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GElf_Shdr* h = gelf_getshdr(section, &mem);
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if (h->sh_type == SHT_GNU_versym)
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versym = section;
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else if (h->sh_type == SHT_GNU_verdef)
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verdef = section;
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else if (h->sh_type == SHT_GNU_verneed)
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verneed = section;
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}
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if (versym || verdef || verneed)
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{
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// At least one the versionning sections was found. Return it.
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versym_section = versym;
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verdef_section = verdef;
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verneed_section = verneed;
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return true;
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}
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return false;
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}
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/// Get the version definition (from the SHT_GNU_verdef section) of a
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/// given symbol represented by a pointer to GElf_Versym.
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///
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/// @param elf_hande the elf handle to use.
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///
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/// @param versym the symbol to get the version definition for.
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///
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/// @param verdef_section the SHT_GNU_verdef section.
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///
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/// @param version the resulting version definition. This is set iff
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/// the function returns true.
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///
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/// @return true upon successful completion, false otherwise.
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static bool
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get_version_definition_for_versym(Elf* elf_handle,
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GElf_Versym* versym,
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Elf_Scn* verdef_section,
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elf_symbol::version& version)
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{
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Elf_Data* verdef_data = elf_getdata(verdef_section, NULL);
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GElf_Verdef verdef_mem;
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GElf_Verdef* verdef = gelf_getverdef(verdef_data, 0, &verdef_mem);
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size_t vd_offset = 0;
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for (;; vd_offset += verdef->vd_next)
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{
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for (;verdef != 0;)
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{
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if (verdef->vd_ndx == (*versym & 0x7fff))
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// Found the version of the symbol.
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break;
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vd_offset += verdef->vd_next;
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verdef = (verdef->vd_next == 0
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? 0
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: gelf_getverdef(verdef_data, vd_offset, &verdef_mem));
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}
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if (verdef != 0)
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{
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GElf_Verdaux verdaux_mem;
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GElf_Verdaux *verdaux = gelf_getverdaux(verdef_data,
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vd_offset + verdef->vd_aux,
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&verdaux_mem);
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GElf_Shdr header_mem;
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GElf_Shdr* verdef_section_header = gelf_getshdr(verdef_section,
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&header_mem);
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size_t verdef_stridx = verdef_section_header->sh_link;
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version.str(elf_strptr(elf_handle, verdef_stridx, verdaux->vda_name));
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if (*versym & 0x8000)
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version.is_default(false);
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else
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version.is_default(true);
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return true;
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}
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if (!verdef || verdef->vd_next == 0)
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break;
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}
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return false;
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}
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/// Get the version needed (from the SHT_GNU_verneed section) to
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/// resolve an undefined symbol represented by a pointer to
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/// GElf_Versym.
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///
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/// @param elf_hande the elf handle to use.
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///
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/// @param versym the symbol to get the version definition for.
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///
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/// @param verneed_section the SHT_GNU_verneed section.
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///
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/// @param version the resulting version definition. This is set iff
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/// the function returns true.
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///
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/// @return true upon successful completion, false otherwise.
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static bool
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get_version_needed_for_versym(Elf* elf_handle,
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GElf_Versym* versym,
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Elf_Scn* verneed_section,
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elf_symbol::version& version)
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{
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if (versym == 0 || elf_handle == 0 || verneed_section == 0)
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return false;
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size_t vn_offset = 0;
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Elf_Data* verneed_data = elf_getdata(verneed_section, NULL);
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GElf_Verneed verneed_mem;
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GElf_Verneed* verneed = gelf_getverneed(verneed_data, 0, &verneed_mem);
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for (;verneed; vn_offset += verneed->vn_next)
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{
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size_t vna_offset = vn_offset;
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GElf_Vernaux vernaux_mem;
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GElf_Vernaux *vernaux = gelf_getvernaux(verneed_data,
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vn_offset + verneed->vn_aux,
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&vernaux_mem);
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for (;vernaux != 0 && verneed;)
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{
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if (vernaux->vna_other == *versym)
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// Found the version of the symbol.
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break;
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vna_offset += verneed->vn_next;
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verneed = (verneed->vn_next == 0
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? 0
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: gelf_getverneed(verneed_data, vna_offset, &verneed_mem));
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}
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if (verneed != 0 && vernaux != 0 && vernaux->vna_other == *versym)
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{
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GElf_Shdr header_mem;
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GElf_Shdr* verneed_section_header = gelf_getshdr(verneed_section,
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&header_mem);
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size_t verneed_stridx = verneed_section_header->sh_link;
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version.str(elf_strptr(elf_handle,
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verneed_stridx,
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vernaux->vna_name));
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if (*versym & 0x8000)
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version.is_default(false);
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else
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version.is_default(true);
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return true;
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}
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if (!verneed || verneed->vn_next == 0)
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break;
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}
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return false;
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}
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/// Return the version for a symbol that is at a given index in its
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/// SHT_SYMTAB section.
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///
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/// @param elf_handle the elf handle to use.
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///
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/// @param symbol_index the index of the symbol to consider.
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///
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/// @param get_def_version if this is true, it means that that we want
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/// the version for a defined symbol; in that case, the version is
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/// looked for in a section of type SHT_GNU_verdef. Otherwise, if
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/// this parameter is false, this means that we want the version for
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/// an undefined symbol; in that case, the version is the needed one
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/// for the symbol to be resolved; so the version is looked fo in a
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/// section of type SHT_GNU_verneed.
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///
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/// @param version the version found for symbol at @p symbol_index.
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///
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/// @return true iff a version was found for symbol at index @p
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/// symbol_index.
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static bool
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get_version_for_symbol(Elf* elf_handle,
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size_t symbol_index,
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bool get_def_version,
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elf_symbol::version& version)
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{
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Elf_Scn *versym_section = NULL,
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*verdef_section = NULL,
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*verneed_section = NULL;
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if (!get_symbol_versionning_sections(elf_handle,
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versym_section,
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verdef_section,
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verneed_section))
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return false;
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GElf_Versym versym_mem;
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Elf_Data* versym_data = (versym_section)
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? elf_getdata(versym_section, NULL)
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: NULL;
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GElf_Versym* versym = (versym_data)
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? gelf_getversym(versym_data, symbol_index, &versym_mem)
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: NULL;
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if (versym == 0 || *versym <= 1)
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// I got these value from the code of readelf.c in elfutils.
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// Apparently, if the symbol version entry has these values, the
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// symbol must be discarded. This is not documented in the
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// official specification.
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return false;
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if (get_def_version)
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{
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if (*versym == 0x8001)
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// I got this value from the code of readelf.c in elfutils
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// too. It's not really documented in the official
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// specification.
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return false;
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if (verdef_section
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&& get_version_definition_for_versym(elf_handle, versym,
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verdef_section, version))
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return true;
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}
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else
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{
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if (verneed_section
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&& get_version_needed_for_versym(elf_handle, versym,
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verneed_section, version))
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return true;
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}
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return false;
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}
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/// Lookup a symbol using the SysV ELF hash table.
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///
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/// Note that this function hasn't been tested. So it hasn't been
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@ -500,6 +500,257 @@ Elf_Scn*
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find_data1_section(Elf* elf_handle)
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{return find_section(elf_handle, ".data1", SHT_PROGBITS);}
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/// Return the SHT_GNU_versym, SHT_GNU_verdef and SHT_GNU_verneed
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/// sections that are involved in symbol versionning.
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///
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/// @param elf_handle the elf handle to use.
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///
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/// @param versym_section the SHT_GNU_versym section found. If the
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/// section wasn't found, this is set to nil.
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///
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/// @param verdef_section the SHT_GNU_verdef section found. If the
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/// section wasn't found, this is set to nil.
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///
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/// @param verneed_section the SHT_GNU_verneed section found. If the
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/// section wasn't found, this is set to nil.
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///
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/// @return true iff at least one of the sections where found.
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bool
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get_symbol_versionning_sections(Elf* elf_handle,
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Elf_Scn*& versym_section,
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Elf_Scn*& verdef_section,
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Elf_Scn*& verneed_section)
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{
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Elf_Scn* section = NULL;
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GElf_Shdr mem;
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Elf_Scn* versym = NULL, *verdef = NULL, *verneed = NULL;
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while ((section = elf_nextscn(elf_handle, section)) != NULL)
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{
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GElf_Shdr* h = gelf_getshdr(section, &mem);
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if (h->sh_type == SHT_GNU_versym)
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versym = section;
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else if (h->sh_type == SHT_GNU_verdef)
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verdef = section;
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else if (h->sh_type == SHT_GNU_verneed)
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verneed = section;
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}
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if (versym || verdef || verneed)
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{
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// At least one the versionning sections was found. Return it.
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versym_section = versym;
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verdef_section = verdef;
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verneed_section = verneed;
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return true;
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}
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return false;
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}
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/// Get the version definition (from the SHT_GNU_verdef section) of a
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/// given symbol represented by a pointer to GElf_Versym.
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///
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/// @param elf_hande the elf handle to use.
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///
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/// @param versym the symbol to get the version definition for.
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///
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/// @param verdef_section the SHT_GNU_verdef section.
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///
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/// @param version the resulting version definition. This is set iff
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/// the function returns true.
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///
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/// @return true upon successful completion, false otherwise.
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bool
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get_version_definition_for_versym(Elf* elf_handle,
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GElf_Versym* versym,
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Elf_Scn* verdef_section,
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elf_symbol::version& version)
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{
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Elf_Data* verdef_data = elf_getdata(verdef_section, NULL);
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GElf_Verdef verdef_mem;
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GElf_Verdef* verdef = gelf_getverdef(verdef_data, 0, &verdef_mem);
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size_t vd_offset = 0;
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for (;; vd_offset += verdef->vd_next)
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{
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for (;verdef != 0;)
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{
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if (verdef->vd_ndx == (*versym & 0x7fff))
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// Found the version of the symbol.
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break;
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vd_offset += verdef->vd_next;
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verdef = (verdef->vd_next == 0
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? 0
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: gelf_getverdef(verdef_data, vd_offset, &verdef_mem));
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}
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if (verdef != 0)
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{
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GElf_Verdaux verdaux_mem;
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GElf_Verdaux *verdaux = gelf_getverdaux(verdef_data,
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vd_offset + verdef->vd_aux,
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&verdaux_mem);
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GElf_Shdr header_mem;
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GElf_Shdr* verdef_section_header = gelf_getshdr(verdef_section,
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&header_mem);
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size_t verdef_stridx = verdef_section_header->sh_link;
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version.str(elf_strptr(elf_handle, verdef_stridx, verdaux->vda_name));
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if (*versym & 0x8000)
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version.is_default(false);
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else
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version.is_default(true);
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return true;
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}
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if (!verdef || verdef->vd_next == 0)
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break;
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}
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return false;
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}
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/// Get the version needed (from the SHT_GNU_verneed section) to
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/// resolve an undefined symbol represented by a pointer to
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/// GElf_Versym.
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///
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/// @param elf_hande the elf handle to use.
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///
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/// @param versym the symbol to get the version definition for.
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///
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/// @param verneed_section the SHT_GNU_verneed section.
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///
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/// @param version the resulting version definition. This is set iff
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/// the function returns true.
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///
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/// @return true upon successful completion, false otherwise.
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bool
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get_version_needed_for_versym(Elf* elf_handle,
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GElf_Versym* versym,
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Elf_Scn* verneed_section,
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elf_symbol::version& version)
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{
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if (versym == 0 || elf_handle == 0 || verneed_section == 0)
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return false;
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size_t vn_offset = 0;
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Elf_Data* verneed_data = elf_getdata(verneed_section, NULL);
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GElf_Verneed verneed_mem;
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GElf_Verneed* verneed = gelf_getverneed(verneed_data, 0, &verneed_mem);
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for (;verneed; vn_offset += verneed->vn_next)
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{
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size_t vna_offset = vn_offset;
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GElf_Vernaux vernaux_mem;
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GElf_Vernaux *vernaux = gelf_getvernaux(verneed_data,
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vn_offset + verneed->vn_aux,
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&vernaux_mem);
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for (;vernaux != 0 && verneed;)
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{
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if (vernaux->vna_other == *versym)
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// Found the version of the symbol.
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break;
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vna_offset += verneed->vn_next;
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verneed = (verneed->vn_next == 0
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? 0
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: gelf_getverneed(verneed_data, vna_offset, &verneed_mem));
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}
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if (verneed != 0 && vernaux != 0 && vernaux->vna_other == *versym)
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{
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GElf_Shdr header_mem;
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GElf_Shdr* verneed_section_header = gelf_getshdr(verneed_section,
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&header_mem);
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size_t verneed_stridx = verneed_section_header->sh_link;
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version.str(elf_strptr(elf_handle,
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verneed_stridx,
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vernaux->vna_name));
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if (*versym & 0x8000)
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version.is_default(false);
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else
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version.is_default(true);
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||||
return true;
|
||||
}
|
||||
|
||||
if (!verneed || verneed->vn_next == 0)
|
||||
break;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
/// Return the version for a symbol that is at a given index in its
|
||||
/// SHT_SYMTAB section.
|
||||
///
|
||||
/// @param elf_handle the elf handle to use.
|
||||
///
|
||||
/// @param symbol_index the index of the symbol to consider.
|
||||
///
|
||||
/// @param get_def_version if this is true, it means that that we want
|
||||
/// the version for a defined symbol; in that case, the version is
|
||||
/// looked for in a section of type SHT_GNU_verdef. Otherwise, if
|
||||
/// this parameter is false, this means that we want the version for
|
||||
/// an undefined symbol; in that case, the version is the needed one
|
||||
/// for the symbol to be resolved; so the version is looked fo in a
|
||||
/// section of type SHT_GNU_verneed.
|
||||
///
|
||||
/// @param version the version found for symbol at @p symbol_index.
|
||||
///
|
||||
/// @return true iff a version was found for symbol at index @p
|
||||
/// symbol_index.
|
||||
bool
|
||||
get_version_for_symbol(Elf* elf_handle,
|
||||
size_t symbol_index,
|
||||
bool get_def_version,
|
||||
elf_symbol::version& version)
|
||||
{
|
||||
Elf_Scn *versym_section = NULL,
|
||||
*verdef_section = NULL,
|
||||
*verneed_section = NULL;
|
||||
|
||||
if (!get_symbol_versionning_sections(elf_handle,
|
||||
versym_section,
|
||||
verdef_section,
|
||||
verneed_section))
|
||||
return false;
|
||||
|
||||
GElf_Versym versym_mem;
|
||||
Elf_Data* versym_data = (versym_section)
|
||||
? elf_getdata(versym_section, NULL)
|
||||
: NULL;
|
||||
GElf_Versym* versym = (versym_data)
|
||||
? gelf_getversym(versym_data, symbol_index, &versym_mem)
|
||||
: NULL;
|
||||
|
||||
if (versym == 0 || *versym <= 1)
|
||||
// I got these value from the code of readelf.c in elfutils.
|
||||
// Apparently, if the symbol version entry has these values, the
|
||||
// symbol must be discarded. This is not documented in the
|
||||
// official specification.
|
||||
return false;
|
||||
|
||||
if (get_def_version)
|
||||
{
|
||||
if (*versym == 0x8001)
|
||||
// I got this value from the code of readelf.c in elfutils
|
||||
// too. It's not really documented in the official
|
||||
// specification.
|
||||
return false;
|
||||
|
||||
if (verdef_section
|
||||
&& get_version_definition_for_versym(elf_handle, versym,
|
||||
verdef_section, version))
|
||||
return true;
|
||||
}
|
||||
else
|
||||
{
|
||||
if (verneed_section
|
||||
&& get_version_needed_for_versym(elf_handle, versym,
|
||||
verneed_section, version))
|
||||
return true;
|
||||
}
|
||||
|
||||
return false;
|
||||
}
|
||||
|
||||
|
||||
|
||||
} // end namespace elf_helpers
|
||||
} // end namespace abigail
|
||||
|
||||
@ -96,6 +96,34 @@ find_data_section(Elf* elf_handle);
|
||||
Elf_Scn*
|
||||
find_data1_section(Elf* elf_handle);
|
||||
|
||||
bool
|
||||
get_symbol_versionning_sections(Elf* elf_handle,
|
||||
Elf_Scn*& versym_section,
|
||||
Elf_Scn*& verdef_section,
|
||||
Elf_Scn*& verneed_section);
|
||||
|
||||
//
|
||||
// Helpers for symbol versioning
|
||||
//
|
||||
|
||||
bool
|
||||
get_version_definition_for_versym(Elf* elf_handle,
|
||||
GElf_Versym* versym,
|
||||
Elf_Scn* verdef_section,
|
||||
elf_symbol::version& version);
|
||||
|
||||
bool
|
||||
get_version_needed_for_versym(Elf* elf_handle,
|
||||
GElf_Versym* versym,
|
||||
Elf_Scn* verneed_section,
|
||||
elf_symbol::version& version);
|
||||
|
||||
bool
|
||||
get_version_for_symbol(Elf* elf_handle,
|
||||
size_t symbol_index,
|
||||
bool get_def_version,
|
||||
elf_symbol::version& version);
|
||||
|
||||
} // end namespace elf_helpers
|
||||
} // end namespace abigail
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user