| // dynobj.cc -- dynamic object support for gold |
| |
| // Copyright (C) 2006-2021 Free Software Foundation, Inc. |
| // Written by Ian Lance Taylor <iant@google.com>. |
| |
| // This file is part of gold. |
| |
| // 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 "gold.h" |
| |
| #include <vector> |
| #include <cstring> |
| |
| #include "elfcpp.h" |
| #include "parameters.h" |
| #include "script.h" |
| #include "symtab.h" |
| #include "dynobj.h" |
| |
| namespace gold |
| { |
| |
| // Class Dynobj. |
| |
| // Sets up the default soname_ to use, in the (rare) cases we never |
| // see a DT_SONAME entry. |
| |
| Dynobj::Dynobj(const std::string& name, Input_file* input_file, off_t offset) |
| : Object(name, input_file, true, offset), |
| needed_(), |
| unknown_needed_(UNKNOWN_NEEDED_UNSET) |
| { |
| // This will be overridden by a DT_SONAME entry, hopefully. But if |
| // we never see a DT_SONAME entry, our rule is to use the dynamic |
| // object's filename. The only exception is when the dynamic object |
| // is part of an archive (so the filename is the archive's |
| // filename). In that case, we use just the dynobj's name-in-archive. |
| if (input_file == NULL) |
| this->soname_ = name; |
| else |
| { |
| this->soname_ = input_file->found_name(); |
| if (this->offset() != 0) |
| { |
| std::string::size_type open_paren = this->name().find('('); |
| std::string::size_type close_paren = this->name().find(')'); |
| if (open_paren != std::string::npos |
| && close_paren != std::string::npos) |
| { |
| // It's an archive, and name() is of the form 'foo.a(bar.so)'. |
| open_paren += 1; |
| this->soname_ = this->name().substr(open_paren, |
| close_paren - open_paren); |
| } |
| } |
| } |
| } |
| |
| // Class Sized_dynobj. |
| |
| template<int size, bool big_endian> |
| Sized_dynobj<size, big_endian>::Sized_dynobj( |
| const std::string& name, |
| Input_file* input_file, |
| off_t offset, |
| const elfcpp::Ehdr<size, big_endian>& ehdr) |
| : Dynobj(name, input_file, offset), |
| elf_file_(this, ehdr), |
| dynsym_shndx_(-1U), |
| symbols_(NULL), |
| defined_count_(0) |
| { |
| } |
| |
| // Set up the object. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::setup() |
| { |
| const unsigned int shnum = this->elf_file_.shnum(); |
| this->set_shnum(shnum); |
| } |
| |
| // Find the SHT_DYNSYM section and the various version sections, and |
| // the dynamic section, given the section headers. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::find_dynsym_sections( |
| const unsigned char* pshdrs, |
| unsigned int* pversym_shndx, |
| unsigned int* pverdef_shndx, |
| unsigned int* pverneed_shndx, |
| unsigned int* pdynamic_shndx) |
| { |
| *pversym_shndx = -1U; |
| *pverdef_shndx = -1U; |
| *pverneed_shndx = -1U; |
| *pdynamic_shndx = -1U; |
| |
| unsigned int symtab_shndx = 0; |
| unsigned int xindex_shndx = 0; |
| unsigned int xindex_link = 0; |
| const unsigned int shnum = this->shnum(); |
| const unsigned char* p = pshdrs; |
| for (unsigned int i = 0; i < shnum; ++i, p += This::shdr_size) |
| { |
| typename This::Shdr shdr(p); |
| |
| unsigned int* pi; |
| switch (shdr.get_sh_type()) |
| { |
| case elfcpp::SHT_DYNSYM: |
| this->dynsym_shndx_ = i; |
| if (xindex_shndx > 0 && xindex_link == i) |
| { |
| Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset()); |
| xindex->read_symtab_xindex<size, big_endian>(this, xindex_shndx, |
| pshdrs); |
| this->set_xindex(xindex); |
| } |
| pi = NULL; |
| break; |
| case elfcpp::SHT_SYMTAB: |
| symtab_shndx = i; |
| pi = NULL; |
| break; |
| case elfcpp::SHT_GNU_versym: |
| pi = pversym_shndx; |
| break; |
| case elfcpp::SHT_GNU_verdef: |
| pi = pverdef_shndx; |
| break; |
| case elfcpp::SHT_GNU_verneed: |
| pi = pverneed_shndx; |
| break; |
| case elfcpp::SHT_DYNAMIC: |
| pi = pdynamic_shndx; |
| break; |
| case elfcpp::SHT_SYMTAB_SHNDX: |
| xindex_shndx = i; |
| xindex_link = this->adjust_shndx(shdr.get_sh_link()); |
| if (xindex_link == this->dynsym_shndx_) |
| { |
| Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset()); |
| xindex->read_symtab_xindex<size, big_endian>(this, xindex_shndx, |
| pshdrs); |
| this->set_xindex(xindex); |
| } |
| pi = NULL; |
| break; |
| default: |
| pi = NULL; |
| break; |
| } |
| |
| if (pi == NULL) |
| continue; |
| |
| if (*pi != -1U) |
| this->error(_("unexpected duplicate type %u section: %u, %u"), |
| shdr.get_sh_type(), *pi, i); |
| |
| *pi = i; |
| } |
| |
| // If there is no dynamic symbol table, use the normal symbol table. |
| // On some SVR4 systems, a shared library is stored in an archive. |
| // The version stored in the archive only has a normal symbol table. |
| // It has an SONAME entry which points to another copy in the file |
| // system which has a dynamic symbol table as usual. This is way of |
| // addressing the issues which glibc addresses using GROUP with |
| // libc_nonshared.a. |
| if (this->dynsym_shndx_ == -1U && symtab_shndx != 0) |
| { |
| this->dynsym_shndx_ = symtab_shndx; |
| if (xindex_shndx > 0 && xindex_link == symtab_shndx) |
| { |
| Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset()); |
| xindex->read_symtab_xindex<size, big_endian>(this, xindex_shndx, |
| pshdrs); |
| this->set_xindex(xindex); |
| } |
| } |
| } |
| |
| // Read the contents of section SHNDX. PSHDRS points to the section |
| // headers. TYPE is the expected section type. LINK is the expected |
| // section link. Store the data in *VIEW and *VIEW_SIZE. The |
| // section's sh_info field is stored in *VIEW_INFO. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::read_dynsym_section( |
| const unsigned char* pshdrs, |
| unsigned int shndx, |
| elfcpp::SHT type, |
| unsigned int link, |
| File_view** view, |
| section_size_type* view_size, |
| unsigned int* view_info) |
| { |
| if (shndx == -1U) |
| { |
| *view = NULL; |
| *view_size = 0; |
| *view_info = 0; |
| return; |
| } |
| |
| typename This::Shdr shdr(pshdrs + shndx * This::shdr_size); |
| |
| gold_assert(shdr.get_sh_type() == type); |
| |
| if (this->adjust_shndx(shdr.get_sh_link()) != link) |
| this->error(_("unexpected link in section %u header: %u != %u"), |
| shndx, this->adjust_shndx(shdr.get_sh_link()), link); |
| |
| *view = this->get_lasting_view(shdr.get_sh_offset(), shdr.get_sh_size(), |
| true, false); |
| *view_size = convert_to_section_size_type(shdr.get_sh_size()); |
| *view_info = shdr.get_sh_info(); |
| } |
| |
| // Read the dynamic tags. Set the soname field if this shared object |
| // has a DT_SONAME tag. Record the DT_NEEDED tags. PSHDRS points to |
| // the section headers. DYNAMIC_SHNDX is the section index of the |
| // SHT_DYNAMIC section. STRTAB_SHNDX, STRTAB, and STRTAB_SIZE are the |
| // section index and contents of a string table which may be the one |
| // associated with the SHT_DYNAMIC section. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::read_dynamic(const unsigned char* pshdrs, |
| unsigned int dynamic_shndx, |
| unsigned int strtab_shndx, |
| const unsigned char* strtabu, |
| off_t strtab_size) |
| { |
| typename This::Shdr dynamicshdr(pshdrs + dynamic_shndx * This::shdr_size); |
| gold_assert(dynamicshdr.get_sh_type() == elfcpp::SHT_DYNAMIC); |
| |
| const off_t dynamic_size = dynamicshdr.get_sh_size(); |
| const unsigned char* pdynamic = this->get_view(dynamicshdr.get_sh_offset(), |
| dynamic_size, true, false); |
| |
| const unsigned int link = this->adjust_shndx(dynamicshdr.get_sh_link()); |
| if (link != strtab_shndx) |
| { |
| if (link >= this->shnum()) |
| { |
| this->error(_("DYNAMIC section %u link out of range: %u"), |
| dynamic_shndx, link); |
| return; |
| } |
| |
| typename This::Shdr strtabshdr(pshdrs + link * This::shdr_size); |
| if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB) |
| { |
| this->error(_("DYNAMIC section %u link %u is not a strtab"), |
| dynamic_shndx, link); |
| return; |
| } |
| |
| strtab_size = strtabshdr.get_sh_size(); |
| strtabu = this->get_view(strtabshdr.get_sh_offset(), strtab_size, false, |
| false); |
| } |
| |
| const char* const strtab = reinterpret_cast<const char*>(strtabu); |
| |
| for (const unsigned char* p = pdynamic; |
| p < pdynamic + dynamic_size; |
| p += This::dyn_size) |
| { |
| typename This::Dyn dyn(p); |
| |
| switch (dyn.get_d_tag()) |
| { |
| case elfcpp::DT_NULL: |
| // We should always see DT_NULL at the end of the dynamic |
| // tags. |
| return; |
| |
| case elfcpp::DT_SONAME: |
| { |
| off_t val = dyn.get_d_val(); |
| if (val >= strtab_size) |
| this->error(_("DT_SONAME value out of range: %lld >= %lld"), |
| static_cast<long long>(val), |
| static_cast<long long>(strtab_size)); |
| else |
| this->set_soname_string(strtab + val); |
| } |
| break; |
| |
| case elfcpp::DT_NEEDED: |
| { |
| off_t val = dyn.get_d_val(); |
| if (val >= strtab_size) |
| this->error(_("DT_NEEDED value out of range: %lld >= %lld"), |
| static_cast<long long>(val), |
| static_cast<long long>(strtab_size)); |
| else |
| this->add_needed(strtab + val); |
| } |
| break; |
| |
| default: |
| break; |
| } |
| } |
| |
| this->error(_("missing DT_NULL in dynamic segment")); |
| } |
| |
| // Read the symbols and sections from a dynamic object. We read the |
| // dynamic symbols, not the normal symbols. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd) |
| { |
| this->base_read_symbols(sd); |
| } |
| |
| // Read the symbols and sections from a dynamic object. We read the |
| // dynamic symbols, not the normal symbols. This is common code for |
| // all target-specific overrides of do_read_symbols(). |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::base_read_symbols(Read_symbols_data* sd) |
| { |
| this->read_section_data(&this->elf_file_, sd); |
| |
| const unsigned char* const pshdrs = sd->section_headers->data(); |
| |
| unsigned int versym_shndx; |
| unsigned int verdef_shndx; |
| unsigned int verneed_shndx; |
| unsigned int dynamic_shndx; |
| this->find_dynsym_sections(pshdrs, &versym_shndx, &verdef_shndx, |
| &verneed_shndx, &dynamic_shndx); |
| |
| unsigned int strtab_shndx = -1U; |
| |
| sd->symbols = NULL; |
| sd->symbols_size = 0; |
| sd->external_symbols_offset = 0; |
| sd->symbol_names = NULL; |
| sd->symbol_names_size = 0; |
| sd->versym = NULL; |
| sd->versym_size = 0; |
| sd->verdef = NULL; |
| sd->verdef_size = 0; |
| sd->verdef_info = 0; |
| sd->verneed = NULL; |
| sd->verneed_size = 0; |
| sd->verneed_info = 0; |
| |
| const unsigned char* namesu = sd->section_names->data(); |
| const char* names = reinterpret_cast<const char*>(namesu); |
| if (memmem(names, sd->section_names_size, ".zdebug_", 8) != NULL) |
| { |
| Compressed_section_map* compressed_sections = |
| build_compressed_section_map<size, big_endian>( |
| pshdrs, this->shnum(), names, sd->section_names_size, this, true); |
| if (compressed_sections != NULL) |
| this->set_compressed_sections(compressed_sections); |
| } |
| |
| if (this->dynsym_shndx_ != -1U) |
| { |
| // Get the dynamic symbols. |
| typename This::Shdr dynsymshdr(pshdrs |
| + this->dynsym_shndx_ * This::shdr_size); |
| |
| sd->symbols = this->get_lasting_view(dynsymshdr.get_sh_offset(), |
| dynsymshdr.get_sh_size(), true, |
| false); |
| sd->symbols_size = |
| convert_to_section_size_type(dynsymshdr.get_sh_size()); |
| |
| // Get the symbol names. |
| strtab_shndx = this->adjust_shndx(dynsymshdr.get_sh_link()); |
| if (strtab_shndx >= this->shnum()) |
| { |
| this->error(_("invalid dynamic symbol table name index: %u"), |
| strtab_shndx); |
| return; |
| } |
| typename This::Shdr strtabshdr(pshdrs + strtab_shndx * This::shdr_size); |
| if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB) |
| { |
| this->error(_("dynamic symbol table name section " |
| "has wrong type: %u"), |
| static_cast<unsigned int>(strtabshdr.get_sh_type())); |
| return; |
| } |
| |
| sd->symbol_names = this->get_lasting_view(strtabshdr.get_sh_offset(), |
| strtabshdr.get_sh_size(), |
| false, false); |
| sd->symbol_names_size = |
| convert_to_section_size_type(strtabshdr.get_sh_size()); |
| |
| // Get the version information. |
| |
| unsigned int dummy; |
| this->read_dynsym_section(pshdrs, versym_shndx, elfcpp::SHT_GNU_versym, |
| this->dynsym_shndx_, |
| &sd->versym, &sd->versym_size, &dummy); |
| |
| // We require that the version definition and need section link |
| // to the same string table as the dynamic symbol table. This |
| // is not a technical requirement, but it always happens in |
| // practice. We could change this if necessary. |
| |
| this->read_dynsym_section(pshdrs, verdef_shndx, elfcpp::SHT_GNU_verdef, |
| strtab_shndx, &sd->verdef, &sd->verdef_size, |
| &sd->verdef_info); |
| |
| this->read_dynsym_section(pshdrs, verneed_shndx, elfcpp::SHT_GNU_verneed, |
| strtab_shndx, &sd->verneed, &sd->verneed_size, |
| &sd->verneed_info); |
| } |
| |
| // Read the SHT_DYNAMIC section to find whether this shared object |
| // has a DT_SONAME tag and to record any DT_NEEDED tags. This |
| // doesn't really have anything to do with reading the symbols, but |
| // this is a convenient place to do it. |
| if (dynamic_shndx != -1U) |
| this->read_dynamic(pshdrs, dynamic_shndx, strtab_shndx, |
| (sd->symbol_names == NULL |
| ? NULL |
| : sd->symbol_names->data()), |
| sd->symbol_names_size); |
| } |
| |
| // Return the Xindex structure to use for object with lots of |
| // sections. |
| |
| template<int size, bool big_endian> |
| Xindex* |
| Sized_dynobj<size, big_endian>::do_initialize_xindex() |
| { |
| gold_assert(this->dynsym_shndx_ != -1U); |
| Xindex* xindex = new Xindex(this->elf_file_.large_shndx_offset()); |
| xindex->initialize_symtab_xindex<size, big_endian>(this, this->dynsym_shndx_); |
| return xindex; |
| } |
| |
| // Lay out the input sections for a dynamic object. We don't want to |
| // include sections from a dynamic object, so all that we actually do |
| // here is check for .gnu.warning and .note.GNU-split-stack sections. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::do_layout(Symbol_table* symtab, |
| Layout*, |
| Read_symbols_data* sd) |
| { |
| const unsigned int shnum = this->shnum(); |
| if (shnum == 0) |
| return; |
| |
| // Get the section headers. |
| const unsigned char* pshdrs = sd->section_headers->data(); |
| |
| // Get the section names. |
| const unsigned char* pnamesu = sd->section_names->data(); |
| const char* pnames = reinterpret_cast<const char*>(pnamesu); |
| |
| // Skip the first, dummy, section. |
| pshdrs += This::shdr_size; |
| for (unsigned int i = 1; i < shnum; ++i, pshdrs += This::shdr_size) |
| { |
| typename This::Shdr shdr(pshdrs); |
| |
| if (shdr.get_sh_name() >= sd->section_names_size) |
| { |
| this->error(_("bad section name offset for section %u: %lu"), |
| i, static_cast<unsigned long>(shdr.get_sh_name())); |
| return; |
| } |
| |
| const char* name = pnames + shdr.get_sh_name(); |
| |
| this->handle_gnu_warning_section(name, i, symtab); |
| this->handle_split_stack_section(name); |
| } |
| |
| delete sd->section_headers; |
| sd->section_headers = NULL; |
| delete sd->section_names; |
| sd->section_names = NULL; |
| } |
| |
| // Add an entry to the vector mapping version numbers to version |
| // strings. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::set_version_map( |
| Version_map* version_map, |
| unsigned int ndx, |
| const char* name) const |
| { |
| if (ndx >= version_map->size()) |
| version_map->resize(ndx + 1); |
| if ((*version_map)[ndx] != NULL) |
| this->error(_("duplicate definition for version %u"), ndx); |
| (*version_map)[ndx] = name; |
| } |
| |
| // Add mappings for the version definitions to VERSION_MAP. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::make_verdef_map( |
| Read_symbols_data* sd, |
| Version_map* version_map) const |
| { |
| if (sd->verdef == NULL) |
| return; |
| |
| const char* names = reinterpret_cast<const char*>(sd->symbol_names->data()); |
| section_size_type names_size = sd->symbol_names_size; |
| |
| const unsigned char* pverdef = sd->verdef->data(); |
| section_size_type verdef_size = sd->verdef_size; |
| const unsigned int count = sd->verdef_info; |
| |
| const unsigned char* p = pverdef; |
| for (unsigned int i = 0; i < count; ++i) |
| { |
| elfcpp::Verdef<size, big_endian> verdef(p); |
| |
| if (verdef.get_vd_version() != elfcpp::VER_DEF_CURRENT) |
| { |
| this->error(_("unexpected verdef version %u"), |
| verdef.get_vd_version()); |
| return; |
| } |
| |
| const section_size_type vd_ndx = verdef.get_vd_ndx(); |
| |
| // The GNU linker clears the VERSYM_HIDDEN bit. I'm not |
| // sure why. |
| |
| // The first Verdaux holds the name of this version. Subsequent |
| // ones are versions that this one depends upon, which we don't |
| // care about here. |
| const section_size_type vd_cnt = verdef.get_vd_cnt(); |
| if (vd_cnt < 1) |
| { |
| this->error(_("verdef vd_cnt field too small: %u"), |
| static_cast<unsigned int>(vd_cnt)); |
| return; |
| } |
| |
| const section_size_type vd_aux = verdef.get_vd_aux(); |
| if ((p - pverdef) + vd_aux >= verdef_size) |
| { |
| this->error(_("verdef vd_aux field out of range: %u"), |
| static_cast<unsigned int>(vd_aux)); |
| return; |
| } |
| |
| const unsigned char* pvda = p + vd_aux; |
| elfcpp::Verdaux<size, big_endian> verdaux(pvda); |
| |
| const section_size_type vda_name = verdaux.get_vda_name(); |
| if (vda_name >= names_size) |
| { |
| this->error(_("verdaux vda_name field out of range: %u"), |
| static_cast<unsigned int>(vda_name)); |
| return; |
| } |
| |
| this->set_version_map(version_map, vd_ndx, names + vda_name); |
| |
| const section_size_type vd_next = verdef.get_vd_next(); |
| if ((p - pverdef) + vd_next >= verdef_size) |
| { |
| this->error(_("verdef vd_next field out of range: %u"), |
| static_cast<unsigned int>(vd_next)); |
| return; |
| } |
| |
| p += vd_next; |
| } |
| } |
| |
| // Add mappings for the required versions to VERSION_MAP. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::make_verneed_map( |
| Read_symbols_data* sd, |
| Version_map* version_map) const |
| { |
| if (sd->verneed == NULL) |
| return; |
| |
| const char* names = reinterpret_cast<const char*>(sd->symbol_names->data()); |
| section_size_type names_size = sd->symbol_names_size; |
| |
| const unsigned char* pverneed = sd->verneed->data(); |
| const section_size_type verneed_size = sd->verneed_size; |
| const unsigned int count = sd->verneed_info; |
| |
| const unsigned char* p = pverneed; |
| for (unsigned int i = 0; i < count; ++i) |
| { |
| elfcpp::Verneed<size, big_endian> verneed(p); |
| |
| if (verneed.get_vn_version() != elfcpp::VER_NEED_CURRENT) |
| { |
| this->error(_("unexpected verneed version %u"), |
| verneed.get_vn_version()); |
| return; |
| } |
| |
| const section_size_type vn_aux = verneed.get_vn_aux(); |
| |
| if ((p - pverneed) + vn_aux >= verneed_size) |
| { |
| this->error(_("verneed vn_aux field out of range: %u"), |
| static_cast<unsigned int>(vn_aux)); |
| return; |
| } |
| |
| const unsigned int vn_cnt = verneed.get_vn_cnt(); |
| const unsigned char* pvna = p + vn_aux; |
| for (unsigned int j = 0; j < vn_cnt; ++j) |
| { |
| elfcpp::Vernaux<size, big_endian> vernaux(pvna); |
| |
| const unsigned int vna_name = vernaux.get_vna_name(); |
| if (vna_name >= names_size) |
| { |
| this->error(_("vernaux vna_name field out of range: %u"), |
| static_cast<unsigned int>(vna_name)); |
| return; |
| } |
| |
| this->set_version_map(version_map, vernaux.get_vna_other(), |
| names + vna_name); |
| |
| const section_size_type vna_next = vernaux.get_vna_next(); |
| if ((pvna - pverneed) + vna_next >= verneed_size) |
| { |
| this->error(_("verneed vna_next field out of range: %u"), |
| static_cast<unsigned int>(vna_next)); |
| return; |
| } |
| |
| pvna += vna_next; |
| } |
| |
| const section_size_type vn_next = verneed.get_vn_next(); |
| if ((p - pverneed) + vn_next >= verneed_size) |
| { |
| this->error(_("verneed vn_next field out of range: %u"), |
| static_cast<unsigned int>(vn_next)); |
| return; |
| } |
| |
| p += vn_next; |
| } |
| } |
| |
| // Create a vector mapping version numbers to version strings. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::make_version_map( |
| Read_symbols_data* sd, |
| Version_map* version_map) const |
| { |
| if (sd->verdef == NULL && sd->verneed == NULL) |
| return; |
| |
| // A guess at the maximum version number we will see. If this is |
| // wrong we will be less efficient but still correct. |
| version_map->reserve(sd->verdef_info + sd->verneed_info * 10); |
| |
| this->make_verdef_map(sd, version_map); |
| this->make_verneed_map(sd, version_map); |
| } |
| |
| // Add the dynamic symbols to the symbol table. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::do_add_symbols(Symbol_table* symtab, |
| Read_symbols_data* sd, |
| Layout*) |
| { |
| if (sd->symbols == NULL) |
| { |
| gold_assert(sd->symbol_names == NULL); |
| gold_assert(sd->versym == NULL && sd->verdef == NULL |
| && sd->verneed == NULL); |
| return; |
| } |
| |
| const int sym_size = This::sym_size; |
| const size_t symcount = sd->symbols_size / sym_size; |
| gold_assert(sd->external_symbols_offset == 0); |
| if (symcount * sym_size != sd->symbols_size) |
| { |
| this->error(_("size of dynamic symbols is not multiple of symbol size")); |
| return; |
| } |
| |
| Version_map version_map; |
| this->make_version_map(sd, &version_map); |
| |
| // If printing symbol counts or a cross reference table or |
| // preparing for an incremental link, we want to track symbols. |
| if (parameters->options().user_set_print_symbol_counts() |
| || parameters->options().cref() |
| || parameters->incremental()) |
| { |
| this->symbols_ = new Symbols(); |
| this->symbols_->resize(symcount); |
| } |
| |
| const char* sym_names = |
| reinterpret_cast<const char*>(sd->symbol_names->data()); |
| symtab->add_from_dynobj(this, sd->symbols->data(), symcount, |
| sym_names, sd->symbol_names_size, |
| (sd->versym == NULL |
| ? NULL |
| : sd->versym->data()), |
| sd->versym_size, |
| &version_map, |
| this->symbols_, |
| &this->defined_count_); |
| |
| delete sd->symbols; |
| sd->symbols = NULL; |
| delete sd->symbol_names; |
| sd->symbol_names = NULL; |
| if (sd->versym != NULL) |
| { |
| delete sd->versym; |
| sd->versym = NULL; |
| } |
| if (sd->verdef != NULL) |
| { |
| delete sd->verdef; |
| sd->verdef = NULL; |
| } |
| if (sd->verneed != NULL) |
| { |
| delete sd->verneed; |
| sd->verneed = NULL; |
| } |
| |
| // This is normally the last time we will read any data from this |
| // file. |
| this->clear_view_cache_marks(); |
| } |
| |
| template<int size, bool big_endian> |
| Archive::Should_include |
| Sized_dynobj<size, big_endian>::do_should_include_member(Symbol_table*, |
| Layout*, |
| Read_symbols_data*, |
| std::string*) |
| { |
| return Archive::SHOULD_INCLUDE_YES; |
| } |
| |
| // Iterate over global symbols, calling a visitor class V for each. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::do_for_all_global_symbols( |
| Read_symbols_data* sd, |
| Library_base::Symbol_visitor_base* v) |
| { |
| const char* sym_names = |
| reinterpret_cast<const char*>(sd->symbol_names->data()); |
| const unsigned char* syms = |
| sd->symbols->data() + sd->external_symbols_offset; |
| const int sym_size = elfcpp::Elf_sizes<size>::sym_size; |
| size_t symcount = ((sd->symbols_size - sd->external_symbols_offset) |
| / sym_size); |
| const unsigned char* p = syms; |
| |
| for (size_t i = 0; i < symcount; ++i, p += sym_size) |
| { |
| elfcpp::Sym<size, big_endian> sym(p); |
| if (sym.get_st_shndx() != elfcpp::SHN_UNDEF |
| && sym.get_st_bind() != elfcpp::STB_LOCAL) |
| v->visit(sym_names + sym.get_st_name()); |
| } |
| } |
| |
| // Iterate over local symbols, calling a visitor class V for each GOT offset |
| // associated with a local symbol. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::do_for_all_local_got_entries( |
| Got_offset_list::Visitor*) const |
| { |
| } |
| |
| // Get symbol counts. |
| |
| template<int size, bool big_endian> |
| void |
| Sized_dynobj<size, big_endian>::do_get_global_symbol_counts( |
| const Symbol_table*, |
| size_t* defined, |
| size_t* used) const |
| { |
| *defined = this->defined_count_; |
| size_t count = 0; |
| for (typename Symbols::const_iterator p = this->symbols_->begin(); |
| p != this->symbols_->end(); |
| ++p) |
| if (*p != NULL |
| && (*p)->source() == Symbol::FROM_OBJECT |
| && (*p)->object() == this |
| && (*p)->is_defined() |
| && (*p)->has_dynsym_index()) |
| ++count; |
| *used = count; |
| } |
| |
| // Given a vector of hash codes, compute the number of hash buckets to |
| // use. |
| |
| unsigned int |
| Dynobj::compute_bucket_count(const std::vector<uint32_t>& hashcodes, |
| bool for_gnu_hash_table) |
| { |
| // FIXME: Implement optional hash table optimization. |
| |
| // Array used to determine the number of hash table buckets to use |
| // based on the number of symbols there are. If there are fewer |
| // than 3 symbols we use 1 bucket, fewer than 17 symbols we use 3 |
| // buckets, fewer than 37 we use 17 buckets, and so forth. We never |
| // use more than 262147 buckets. This is straight from the old GNU |
| // linker. |
| static const unsigned int buckets[] = |
| { |
| 1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209, |
| 16411, 32771, 65537, 131101, 262147 |
| }; |
| const int buckets_count = sizeof buckets / sizeof buckets[0]; |
| |
| unsigned int symcount = hashcodes.size(); |
| unsigned int ret = 1; |
| const double full_fraction |
| = 1.0 - parameters->options().hash_bucket_empty_fraction(); |
| for (int i = 0; i < buckets_count; ++i) |
| { |
| if (symcount < buckets[i] * full_fraction) |
| break; |
| ret = buckets[i]; |
| } |
| |
| if (for_gnu_hash_table && ret < 2) |
| ret = 2; |
| |
| return ret; |
| } |
| |
| // The standard ELF hash function. This hash function must not |
| // change, as the dynamic linker uses it also. |
| |
| uint32_t |
| Dynobj::elf_hash(const char* name) |
| { |
| const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name); |
| uint32_t h = 0; |
| unsigned char c; |
| while ((c = *nameu++) != '\0') |
| { |
| h = (h << 4) + c; |
| uint32_t g = h & 0xf0000000; |
| if (g != 0) |
| { |
| h ^= g >> 24; |
| // The ELF ABI says h &= ~g, but using xor is equivalent in |
| // this case (since g was set from h) and may save one |
| // instruction. |
| h ^= g; |
| } |
| } |
| return h; |
| } |
| |
| // Create a standard ELF hash table, setting *PPHASH and *PHASHLEN. |
| // DYNSYMS is a vector with all the global dynamic symbols. |
| // LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic |
| // symbol table. |
| |
| void |
| Dynobj::create_elf_hash_table(const std::vector<Symbol*>& dynsyms, |
| unsigned int local_dynsym_count, |
| unsigned char** pphash, |
| unsigned int* phashlen) |
| { |
| unsigned int dynsym_count = dynsyms.size(); |
| |
| // Get the hash values for all the symbols. |
| std::vector<uint32_t> dynsym_hashvals(dynsym_count); |
| for (unsigned int i = 0; i < dynsym_count; ++i) |
| dynsym_hashvals[i] = Dynobj::elf_hash(dynsyms[i]->name()); |
| |
| const unsigned int bucketcount = |
| Dynobj::compute_bucket_count(dynsym_hashvals, false); |
| |
| std::vector<uint32_t> bucket(bucketcount); |
| std::vector<uint32_t> chain(local_dynsym_count + dynsym_count); |
| |
| for (unsigned int i = 0; i < dynsym_count; ++i) |
| { |
| unsigned int dynsym_index = dynsyms[i]->dynsym_index(); |
| unsigned int bucketpos = dynsym_hashvals[i] % bucketcount; |
| chain[dynsym_index] = bucket[bucketpos]; |
| bucket[bucketpos] = dynsym_index; |
| } |
| |
| int size = parameters->target().hash_entry_size(); |
| unsigned int hashlen = ((2 |
| + bucketcount |
| + local_dynsym_count |
| + dynsym_count) |
| * size / 8); |
| unsigned char* phash = new unsigned char[hashlen]; |
| |
| bool big_endian = parameters->target().is_big_endian(); |
| if (size == 32) |
| { |
| if (big_endian) |
| { |
| #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) |
| Dynobj::sized_create_elf_hash_table<32, true>(bucket, chain, phash, |
| hashlen); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) |
| Dynobj::sized_create_elf_hash_table<32, false>(bucket, chain, phash, |
| hashlen); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| } |
| else if (size == 64) |
| { |
| if (big_endian) |
| { |
| #if defined(HAVE_TARGET_32_BIG) || defined(HAVE_TARGET_64_BIG) |
| Dynobj::sized_create_elf_hash_table<64, true>(bucket, chain, phash, |
| hashlen); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_64_LITTLE) |
| Dynobj::sized_create_elf_hash_table<64, false>(bucket, chain, phash, |
| hashlen); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| } |
| else |
| gold_unreachable(); |
| |
| *pphash = phash; |
| *phashlen = hashlen; |
| } |
| |
| // Fill in an ELF hash table. |
| |
| template<int size, bool big_endian> |
| void |
| Dynobj::sized_create_elf_hash_table(const std::vector<uint32_t>& bucket, |
| const std::vector<uint32_t>& chain, |
| unsigned char* phash, |
| unsigned int hashlen) |
| { |
| unsigned char* p = phash; |
| |
| const unsigned int bucketcount = bucket.size(); |
| const unsigned int chaincount = chain.size(); |
| |
| elfcpp::Swap<size, big_endian>::writeval(p, bucketcount); |
| p += size / 8; |
| elfcpp::Swap<size, big_endian>::writeval(p, chaincount); |
| p += size / 8; |
| |
| for (unsigned int i = 0; i < bucketcount; ++i) |
| { |
| elfcpp::Swap<size, big_endian>::writeval(p, bucket[i]); |
| p += size / 8; |
| } |
| |
| for (unsigned int i = 0; i < chaincount; ++i) |
| { |
| elfcpp::Swap<size, big_endian>::writeval(p, chain[i]); |
| p += size / 8; |
| } |
| |
| gold_assert(static_cast<unsigned int>(p - phash) == hashlen); |
| } |
| |
| // The hash function used for the GNU hash table. This hash function |
| // must not change, as the dynamic linker uses it also. |
| |
| uint32_t |
| Dynobj::gnu_hash(const char* name) |
| { |
| const unsigned char* nameu = reinterpret_cast<const unsigned char*>(name); |
| uint32_t h = 5381; |
| unsigned char c; |
| while ((c = *nameu++) != '\0') |
| h = (h << 5) + h + c; |
| return h; |
| } |
| |
| // Create a GNU hash table, setting *PPHASH and *PHASHLEN. GNU hash |
| // tables are an extension to ELF which are recognized by the GNU |
| // dynamic linker. They are referenced using dynamic tag DT_GNU_HASH. |
| // TARGET is the target. DYNSYMS is a vector with all the global |
| // symbols which will be going into the dynamic symbol table. |
| // LOCAL_DYNSYM_COUNT is the number of local symbols in the dynamic |
| // symbol table. |
| |
| void |
| Dynobj::create_gnu_hash_table(const std::vector<Symbol*>& dynsyms, |
| unsigned int local_dynsym_count, |
| unsigned char** pphash, |
| unsigned int* phashlen) |
| { |
| const unsigned int count = dynsyms.size(); |
| |
| // Sort the dynamic symbols into two vectors. Symbols which we do |
| // not want to put into the hash table we store into |
| // UNHASHED_DYNSYMS. Symbols which we do want to store we put into |
| // HASHED_DYNSYMS. DYNSYM_HASHVALS is parallel to HASHED_DYNSYMS, |
| // and records the hash codes. |
| |
| std::vector<Symbol*> unhashed_dynsyms; |
| unhashed_dynsyms.reserve(count); |
| |
| std::vector<Symbol*> hashed_dynsyms; |
| hashed_dynsyms.reserve(count); |
| |
| std::vector<uint32_t> dynsym_hashvals; |
| dynsym_hashvals.reserve(count); |
| |
| for (unsigned int i = 0; i < count; ++i) |
| { |
| Symbol* sym = dynsyms[i]; |
| |
| if (!sym->needs_dynsym_value() |
| && (sym->is_undefined() |
| || sym->is_from_dynobj() |
| || sym->is_forced_local())) |
| unhashed_dynsyms.push_back(sym); |
| else |
| { |
| hashed_dynsyms.push_back(sym); |
| dynsym_hashvals.push_back(Dynobj::gnu_hash(sym->name())); |
| } |
| } |
| |
| // Put the unhashed symbols at the start of the global portion of |
| // the dynamic symbol table. |
| const unsigned int unhashed_count = unhashed_dynsyms.size(); |
| unsigned int unhashed_dynsym_index = local_dynsym_count; |
| for (unsigned int i = 0; i < unhashed_count; ++i) |
| { |
| unhashed_dynsyms[i]->set_dynsym_index(unhashed_dynsym_index); |
| ++unhashed_dynsym_index; |
| } |
| |
| // For the actual data generation we call out to a templatized |
| // function. |
| int size = parameters->target().get_size(); |
| bool big_endian = parameters->target().is_big_endian(); |
| if (size == 32) |
| { |
| if (big_endian) |
| { |
| #ifdef HAVE_TARGET_32_BIG |
| Dynobj::sized_create_gnu_hash_table<32, true>(hashed_dynsyms, |
| dynsym_hashvals, |
| unhashed_dynsym_index, |
| pphash, |
| phashlen); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #ifdef HAVE_TARGET_32_LITTLE |
| Dynobj::sized_create_gnu_hash_table<32, false>(hashed_dynsyms, |
| dynsym_hashvals, |
| unhashed_dynsym_index, |
| pphash, |
| phashlen); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| } |
| else if (size == 64) |
| { |
| if (big_endian) |
| { |
| #ifdef HAVE_TARGET_64_BIG |
| Dynobj::sized_create_gnu_hash_table<64, true>(hashed_dynsyms, |
| dynsym_hashvals, |
| unhashed_dynsym_index, |
| pphash, |
| phashlen); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| else |
| { |
| #ifdef HAVE_TARGET_64_LITTLE |
| Dynobj::sized_create_gnu_hash_table<64, false>(hashed_dynsyms, |
| dynsym_hashvals, |
| unhashed_dynsym_index, |
| pphash, |
| phashlen); |
| #else |
| gold_unreachable(); |
| #endif |
| } |
| } |
| else |
| gold_unreachable(); |
| } |
| |
| // Create the actual data for a GNU hash table. This is just a copy |
| // of the code from the old GNU linker. |
| |
| template<int size, bool big_endian> |
| void |
| Dynobj::sized_create_gnu_hash_table( |
| const std::vector<Symbol*>& hashed_dynsyms, |
| const std::vector<uint32_t>& dynsym_hashvals, |
| unsigned int unhashed_dynsym_count, |
| unsigned char** pphash, |
| unsigned int* phashlen) |
| { |
| if (hashed_dynsyms.empty()) |
| { |
| // Special case for the empty hash table. |
| unsigned int hashlen = 5 * 4 + size / 8; |
| unsigned char* phash = new unsigned char[hashlen]; |
| // One empty bucket. |
| elfcpp::Swap<32, big_endian>::writeval(phash, 1); |
| // Symbol index above unhashed symbols. |
| elfcpp::Swap<32, big_endian>::writeval(phash + 4, unhashed_dynsym_count); |
| // One word for bitmask. |
| elfcpp::Swap<32, big_endian>::writeval(phash + 8, 1); |
| // Only bloom filter. |
| elfcpp::Swap<32, big_endian>::writeval(phash + 12, 0); |
| // No valid hashes. |
| elfcpp::Swap<size, big_endian>::writeval(phash + 16, 0); |
| // No hashes in only bucket. |
| elfcpp::Swap<32, big_endian>::writeval(phash + 16 + size / 8, 0); |
| |
| *phashlen = hashlen; |
| *pphash = phash; |
| |
| return; |
| } |
| |
| const unsigned int bucketcount = |
| Dynobj::compute_bucket_count(dynsym_hashvals, true); |
| |
| const unsigned int nsyms = hashed_dynsyms.size(); |
| |
| uint32_t maskbitslog2 = 1; |
| uint32_t x = nsyms >> 1; |
| while (x != 0) |
| { |
| ++maskbitslog2; |
| x >>= 1; |
| } |
| if (maskbitslog2 < 3) |
| maskbitslog2 = 5; |
| else if (((1U << (maskbitslog2 - 2)) & nsyms) != 0) |
| maskbitslog2 += 3; |
| else |
| maskbitslog2 += 2; |
| |
| uint32_t shift1; |
| if (size == 32) |
| shift1 = 5; |
| else |
| { |
| if (maskbitslog2 == 5) |
| maskbitslog2 = 6; |
| shift1 = 6; |
| } |
| uint32_t mask = (1U << shift1) - 1U; |
| uint32_t shift2 = maskbitslog2; |
| uint32_t maskbits = 1U << maskbitslog2; |
| uint32_t maskwords = 1U << (maskbitslog2 - shift1); |
| |
| typedef typename elfcpp::Elf_types<size>::Elf_WXword Word; |
| std::vector<Word> bitmask(maskwords); |
| std::vector<uint32_t> counts(bucketcount); |
| std::vector<uint32_t> indx(bucketcount); |
| uint32_t symindx = unhashed_dynsym_count; |
| |
| // Count the number of times each hash bucket is used. |
| for (unsigned int i = 0; i < nsyms; ++i) |
| ++counts[dynsym_hashvals[i] % bucketcount]; |
| |
| unsigned int cnt = symindx; |
| for (unsigned int i = 0; i < bucketcount; ++i) |
| { |
| indx[i] = cnt; |
| cnt += counts[i]; |
| } |
| |
| unsigned int hashlen = (4 + bucketcount + nsyms) * 4; |
| hashlen += maskbits / 8; |
| unsigned char* phash = new unsigned char[hashlen]; |
| |
| elfcpp::Swap<32, big_endian>::writeval(phash, bucketcount); |
| elfcpp::Swap<32, big_endian>::writeval(phash + 4, symindx); |
| elfcpp::Swap<32, big_endian>::writeval(phash + 8, maskwords); |
| elfcpp::Swap<32, big_endian>::writeval(phash + 12, shift2); |
| |
| unsigned char* p = phash + 16 + maskbits / 8; |
| for (unsigned int i = 0; i < bucketcount; ++i) |
| { |
| if (counts[i] == 0) |
| elfcpp::Swap<32, big_endian>::writeval(p, 0); |
| else |
| elfcpp::Swap<32, big_endian>::writeval(p, indx[i]); |
| p += 4; |
| } |
| |
| for (unsigned int i = 0; i < nsyms; ++i) |
| { |
| Symbol* sym = hashed_dynsyms[i]; |
| uint32_t hashval = dynsym_hashvals[i]; |
| |
| unsigned int bucket = hashval % bucketcount; |
| unsigned int val = ((hashval >> shift1) |
| & ((maskbits >> shift1) - 1)); |
| bitmask[val] |= (static_cast<Word>(1U)) << (hashval & mask); |
| bitmask[val] |= (static_cast<Word>(1U)) << ((hashval >> shift2) & mask); |
| val = hashval & ~ 1U; |
| if (counts[bucket] == 1) |
| { |
| // Last element terminates the chain. |
| val |= 1; |
| } |
| elfcpp::Swap<32, big_endian>::writeval(p + (indx[bucket] - symindx) * 4, |
| val); |
| --counts[bucket]; |
| |
| sym->set_dynsym_index(indx[bucket]); |
| ++indx[bucket]; |
| } |
| |
| p = phash + 16; |
| for (unsigned int i = 0; i < maskwords; ++i) |
| { |
| elfcpp::Swap<size, big_endian>::writeval(p, bitmask[i]); |
| p += size / 8; |
| } |
| |
| *phashlen = hashlen; |
| *pphash = phash; |
| } |
| |
| // Verdef methods. |
| |
| // Write this definition to a buffer for the output section. |
| |
| template<int size, bool big_endian> |
| unsigned char* |
| Verdef::write(const Stringpool* dynpool, bool is_last, unsigned char* pb) const |
| { |
| const int verdef_size = elfcpp::Elf_sizes<size>::verdef_size; |
| const int verdaux_size = elfcpp::Elf_sizes<size>::verdaux_size; |
| |
| elfcpp::Verdef_write<size, big_endian> vd(pb); |
| vd.set_vd_version(elfcpp::VER_DEF_CURRENT); |
| vd.set_vd_flags((this->is_base_ ? elfcpp::VER_FLG_BASE : 0) |
| | (this->is_weak_ ? elfcpp::VER_FLG_WEAK : 0) |
| | (this->is_info_ ? elfcpp::VER_FLG_INFO : 0)); |
| vd.set_vd_ndx(this->index()); |
| vd.set_vd_cnt(1 + this->deps_.size()); |
| vd.set_vd_hash(Dynobj::elf_hash(this->name())); |
| vd.set_vd_aux(verdef_size); |
| vd.set_vd_next(is_last |
| ? 0 |
| : verdef_size + (1 + this->deps_.size()) * verdaux_size); |
| pb += verdef_size; |
| |
| elfcpp::Verdaux_write<size, big_endian> vda(pb); |
| vda.set_vda_name(dynpool->get_offset(this->name())); |
| vda.set_vda_next(this->deps_.empty() ? 0 : verdaux_size); |
| pb += verdaux_size; |
| |
| Deps::const_iterator p; |
| unsigned int i; |
| for (p = this->deps_.begin(), i = 0; |
| p != this->deps_.end(); |
| ++p, ++i) |
| { |
| elfcpp::Verdaux_write<size, big_endian> vda(pb); |
| vda.set_vda_name(dynpool->get_offset(*p)); |
| vda.set_vda_next(i + 1 >= this->deps_.size() ? 0 : verdaux_size); |
| pb += verdaux_size; |
| } |
| |
| return pb; |
| } |
| |
| // Verneed methods. |
| |
| Verneed::~Verneed() |
| { |
| for (Need_versions::iterator p = this->need_versions_.begin(); |
| p != this->need_versions_.end(); |
| ++p) |
| delete *p; |
| } |
| |
| // Add a new version to this file reference. |
| |
| Verneed_version* |
| Verneed::add_name(const char* name) |
| { |
| Verneed_version* vv = new Verneed_version(name); |
| this->need_versions_.push_back(vv); |
| return vv; |
| } |
| |
| // Set the version indexes starting at INDEX. |
| |
| unsigned int |
| Verneed::finalize(unsigned int index) |
| { |
| for (Need_versions::iterator p = this->need_versions_.begin(); |
| p != this->need_versions_.end(); |
| ++p) |
| { |
| (*p)->set_index(index); |
| ++index; |
| } |
| return index; |
| } |
| |
| // Write this list of referenced versions to a buffer for the output |
| // section. |
| |
| template<int size, bool big_endian> |
| unsigned char* |
| Verneed::write(const Stringpool* dynpool, bool is_last, |
| unsigned char* pb) const |
| { |
| const int verneed_size = elfcpp::Elf_sizes<size>::verneed_size; |
| const int vernaux_size = elfcpp::Elf_sizes<size>::vernaux_size; |
| |
| elfcpp::Verneed_write<size, big_endian> vn(pb); |
| vn.set_vn_version(elfcpp::VER_NEED_CURRENT); |
| vn.set_vn_cnt(this->need_versions_.size()); |
| vn.set_vn_file(dynpool->get_offset(this->filename())); |
| vn.set_vn_aux(verneed_size); |
| vn.set_vn_next(is_last |
| ? 0 |
| : verneed_size + this->need_versions_.size() * vernaux_size); |
| pb += verneed_size; |
| |
| Need_versions::const_iterator p; |
| unsigned int i; |
| for (p = this->need_versions_.begin(), i = 0; |
| p != this->need_versions_.end(); |
| ++p, ++i) |
| { |
| elfcpp::Vernaux_write<size, big_endian> vna(pb); |
| vna.set_vna_hash(Dynobj::elf_hash((*p)->version())); |
| // FIXME: We need to sometimes set VER_FLG_WEAK here. |
| vna.set_vna_flags(0); |
| vna.set_vna_other((*p)->index()); |
| vna.set_vna_name(dynpool->get_offset((*p)->version())); |
| vna.set_vna_next(i + 1 >= this->need_versions_.size() |
| ? 0 |
| : vernaux_size); |
| pb += vernaux_size; |
| } |
| |
| return pb; |
| } |
| |
| // Versions methods. |
| |
| Versions::Versions(const Version_script_info& version_script, |
| Stringpool* dynpool) |
| : defs_(), needs_(), version_table_(), |
| is_finalized_(false), version_script_(version_script), |
| needs_base_version_(true) |
| { |
| if (!this->version_script_.empty()) |
| { |
| // Parse the version script, and insert each declared version into |
| // defs_ and version_table_. |
| std::vector<std::string> versions = this->version_script_.get_versions(); |
| |
| if (this->needs_base_version_ && !versions.empty()) |
| this->define_base_version(dynpool); |
| |
| for (size_t k = 0; k < versions.size(); ++k) |
| { |
| Stringpool::Key version_key; |
| const char* version = dynpool->add(versions[k].c_str(), |
| true, &version_key); |
| Verdef* const vd = new Verdef( |
| version, |
| this->version_script_.get_dependencies(version), |
| false, false, false, false); |
| this->defs_.push_back(vd); |
| Key key(version_key, 0); |
| this->version_table_.insert(std::make_pair(key, vd)); |
| } |
| } |
| } |
| |
| Versions::~Versions() |
| { |
| for (Defs::iterator p = this->defs_.begin(); |
| p != this->defs_.end(); |
| ++p) |
| delete *p; |
| |
| for (Needs::iterator p = this->needs_.begin(); |
| p != this->needs_.end(); |
| ++p) |
| delete *p; |
| } |
| |
| // Define the base version of a shared library. The base version definition |
| // must be the first entry in defs_. We insert it lazily so that defs_ is |
| // empty if no symbol versioning is used. Then layout can just drop the |
| // version sections. |
| |
| void |
| Versions::define_base_version(Stringpool* dynpool) |
| { |
| // If we do any versioning at all, we always need a base version, so |
| // define that first. Nothing explicitly declares itself as part of base, |
| // so it doesn't need to be in version_table_. |
| gold_assert(this->defs_.empty()); |
| const char* name = parameters->options().soname(); |
| if (name == NULL) |
| name = parameters->options().output_file_name(); |
| name = dynpool->add(name, false, NULL); |
| Verdef* vdbase = new Verdef(name, std::vector<std::string>(), |
| true, false, false, true); |
| this->defs_.push_back(vdbase); |
| this->needs_base_version_ = false; |
| } |
| |
| // Return the dynamic object which a symbol refers to. |
| |
| Dynobj* |
| Versions::get_dynobj_for_sym(const Symbol_table* symtab, |
| const Symbol* sym) const |
| { |
| if (sym->is_copied_from_dynobj()) |
| return symtab->get_copy_source(sym); |
| else |
| { |
| Object* object = sym->object(); |
| gold_assert(object->is_dynamic()); |
| return static_cast<Dynobj*>(object); |
| } |
| } |
| |
| // Record version information for a symbol going into the dynamic |
| // symbol table. |
| |
| void |
| Versions::record_version(const Symbol_table* symtab, |
| Stringpool* dynpool, const Symbol* sym) |
| { |
| gold_assert(!this->is_finalized_); |
| gold_assert(sym->version() != NULL); |
| |
| // A symbol defined as "sym@" is bound to an unspecified base version. |
| if (sym->version()[0] == '\0') |
| return; |
| |
| Stringpool::Key version_key; |
| const char* version = dynpool->add(sym->version(), false, &version_key); |
| |
| if (!sym->is_from_dynobj() && !sym->is_copied_from_dynobj()) |
| { |
| this->add_def(dynpool, sym, version, version_key); |
| } |
| else |
| { |
| // This is a version reference. |
| Dynobj* dynobj = this->get_dynobj_for_sym(symtab, sym); |
| this->add_need(dynpool, dynobj->soname(), version, version_key); |
| } |
| } |
| |
| // We've found a symbol SYM defined in version VERSION. |
| |
| void |
| Versions::add_def(Stringpool* dynpool, const Symbol* sym, const char* version, |
| Stringpool::Key version_key) |
| { |
| Key k(version_key, 0); |
| Version_base* const vbnull = NULL; |
| std::pair<Version_table::iterator, bool> ins = |
| this->version_table_.insert(std::make_pair(k, vbnull)); |
| |
| if (!ins.second) |
| { |
| // We already have an entry for this version. |
| Version_base* vb = ins.first->second; |
| |
| // We have now seen a symbol in this version, so it is not |
| // weak. |
| gold_assert(vb != NULL); |
| vb->clear_weak(); |
| } |
| else |
| { |
| // If we are creating a shared object, it is an error to |
| // find a definition of a symbol with a version which is not |
| // in the version script. |
| if (parameters->options().shared()) |
| gold_error(_("symbol %s has undefined version %s"), |
| sym->demangled_name().c_str(), version); |
| |
| // When creating a regular executable, automatically define |
| // a new version. |
| if (this->needs_base_version_) |
| this->define_base_version(dynpool); |
| Verdef* vd = new Verdef(version, std::vector<std::string>(), |
| false, false, false, false); |
| this->defs_.push_back(vd); |
| ins.first->second = vd; |
| } |
| } |
| |
| // Add a reference to version NAME in file FILENAME. |
| |
| void |
| Versions::add_need(Stringpool* dynpool, const char* filename, const char* name, |
| Stringpool::Key name_key) |
| { |
| Stringpool::Key filename_key; |
| filename = dynpool->add(filename, true, &filename_key); |
| |
| Key k(name_key, filename_key); |
| Version_base* const vbnull = NULL; |
| std::pair<Version_table::iterator, bool> ins = |
| this->version_table_.insert(std::make_pair(k, vbnull)); |
| |
| if (!ins.second) |
| { |
| // We already have an entry for this filename/version. |
| return; |
| } |
| |
| // See whether we already have this filename. We don't expect many |
| // version references, so we just do a linear search. This could be |
| // replaced by a hash table. |
| Verneed* vn = NULL; |
| for (Needs::iterator p = this->needs_.begin(); |
| p != this->needs_.end(); |
| ++p) |
| { |
| if ((*p)->filename() == filename) |
| { |
| vn = *p; |
| break; |
| } |
| } |
| |
| if (vn == NULL) |
| { |
| // Create base version definition lazily for shared library. |
| if (parameters->options().shared() && this->needs_base_version_) |
| this->define_base_version(dynpool); |
| |
| // We have a new filename. |
| vn = new Verneed(filename); |
| this->needs_.push_back(vn); |
| } |
| |
| ins.first->second = vn->add_name(name); |
| } |
| |
| // Set the version indexes. Create a new dynamic version symbol for |
| // each new version definition. |
| |
| unsigned int |
| Versions::finalize(Symbol_table* symtab, unsigned int dynsym_index, |
| std::vector<Symbol*>* syms) |
| { |
| gold_assert(!this->is_finalized_); |
| |
| unsigned int vi = 1; |
| |
| for (Defs::iterator p = this->defs_.begin(); |
| p != this->defs_.end(); |
| ++p) |
| { |
| (*p)->set_index(vi); |
| ++vi; |
| |
| // Create a version symbol if necessary. |
| if (!(*p)->is_symbol_created()) |
| { |
| Symbol* vsym = symtab->define_as_constant((*p)->name(), |
| (*p)->name(), |
| Symbol_table::PREDEFINED, |
| 0, 0, |
| elfcpp::STT_OBJECT, |
| elfcpp::STB_GLOBAL, |
| elfcpp::STV_DEFAULT, 0, |
| false, false); |
| vsym->set_needs_dynsym_entry(); |
| vsym->set_dynsym_index(dynsym_index); |
| vsym->set_is_default(); |
| ++dynsym_index; |
| syms->push_back(vsym); |
| // The name is already in the dynamic pool. |
| } |
| } |
| |
| // Index 1 is used for global symbols. |
| if (vi == 1) |
| { |
| gold_assert(this->defs_.empty()); |
| vi = 2; |
| } |
| |
| for (Needs::iterator p = this->needs_.begin(); |
| p != this->needs_.end(); |
| ++p) |
| vi = (*p)->finalize(vi); |
| |
| this->is_finalized_ = true; |
| |
| return dynsym_index; |
| } |
| |
| // Return the version index to use for a symbol. This does two hash |
| // table lookups: one in DYNPOOL and one in this->version_table_. |
| // Another approach alternative would be store a pointer in SYM, which |
| // would increase the size of the symbol table. Or perhaps we could |
| // use a hash table from dynamic symbol pointer values to Version_base |
| // pointers. |
| |
| unsigned int |
| Versions::version_index(const Symbol_table* symtab, const Stringpool* dynpool, |
| const Symbol* sym) const |
| { |
| Stringpool::Key version_key; |
| const char* version = dynpool->find(sym->version(), &version_key); |
| gold_assert(version != NULL); |
| |
| Key k; |
| if (!sym->is_from_dynobj() && !sym->is_copied_from_dynobj()) |
| { |
| k = Key(version_key, 0); |
| } |
| else |
| { |
| Dynobj* dynobj = this->get_dynobj_for_sym(symtab, sym); |
| |
| Stringpool::Key filename_key; |
| const char* filename = dynpool->find(dynobj->soname(), &filename_key); |
| gold_assert(filename != NULL); |
| |
| k = Key(version_key, filename_key); |
| } |
| |
| Version_table::const_iterator p = this->version_table_.find(k); |
| gold_assert(p != this->version_table_.end()); |
| |
| return p->second->index(); |
| } |
| |
| // Return an allocated buffer holding the contents of the symbol |
| // version section. |
| |
| template<int size, bool big_endian> |
| void |
| Versions::symbol_section_contents(const Symbol_table* symtab, |
| const Stringpool* dynpool, |
| unsigned int local_symcount, |
| const std::vector<Symbol*>& syms, |
| unsigned char** pp, |
| unsigned int* psize) const |
| { |
| gold_assert(this->is_finalized_); |
| |
| unsigned int sz = (local_symcount + syms.size()) * 2; |
| unsigned char* pbuf = new unsigned char[sz]; |
| |
| for (unsigned int i = 0; i < local_symcount; ++i) |
| elfcpp::Swap<16, big_endian>::writeval(pbuf + i * 2, |
| elfcpp::VER_NDX_LOCAL); |
| |
| for (std::vector<Symbol*>::const_iterator p = syms.begin(); |
| p != syms.end(); |
| ++p) |
| { |
| unsigned int version_index; |
| const char* version = (*p)->version(); |
| if (version == NULL) |
| { |
| if ((*p)->is_defined() && !(*p)->is_from_dynobj()) |
| version_index = elfcpp::VER_NDX_GLOBAL; |
| else |
| version_index = elfcpp::VER_NDX_LOCAL; |
| } |
| else if (version[0] == '\0') |
| version_index = elfcpp::VER_NDX_GLOBAL; |
| else |
| version_index = this->version_index(symtab, dynpool, *p); |
| // If the symbol was defined as foo@V1 instead of foo@@V1, add |
| // the hidden bit. |
| if ((*p)->version() != NULL |
| && (*p)->is_defined() |
| && !(*p)->is_default() |
| && !(*p)->from_dyn()) |
| version_index |= elfcpp::VERSYM_HIDDEN; |
| elfcpp::Swap<16, big_endian>::writeval(pbuf + (*p)->dynsym_index() * 2, |
| version_index); |
| } |
| |
| *pp = pbuf; |
| *psize = sz; |
| } |
| |
| // Return an allocated buffer holding the contents of the version |
| // definition section. |
| |
| template<int size, bool big_endian> |
| void |
| Versions::def_section_contents(const Stringpool* dynpool, |
| unsigned char** pp, unsigned int* psize, |
| unsigned int* pentries) const |
| { |
| gold_assert(this->is_finalized_); |
| gold_assert(!this->defs_.empty()); |
| |
| const int verdef_size = elfcpp::Elf_sizes<size>::verdef_size; |
| const int verdaux_size = elfcpp::Elf_sizes<size>::verdaux_size; |
| |
| unsigned int sz = 0; |
| for (Defs::const_iterator p = this->defs_.begin(); |
| p != this->defs_.end(); |
| ++p) |
| { |
| sz += verdef_size + verdaux_size; |
| sz += (*p)->count_dependencies() * verdaux_size; |
| } |
| |
| unsigned char* pbuf = new unsigned char[sz]; |
| |
| unsigned char* pb = pbuf; |
| Defs::const_iterator p; |
| unsigned int i; |
| for (p = this->defs_.begin(), i = 0; |
| p != this->defs_.end(); |
| ++p, ++i) |
| pb = (*p)->write<size, big_endian>(dynpool, |
| i + 1 >= this->defs_.size(), |
| pb); |
| |
| gold_assert(static_cast<unsigned int>(pb - pbuf) == sz); |
| |
| *pp = pbuf; |
| *psize = sz; |
| *pentries = this->defs_.size(); |
| } |
| |
| // Return an allocated buffer holding the contents of the version |
| // reference section. |
| |
| template<int size, bool big_endian> |
| void |
| Versions::need_section_contents(const Stringpool* dynpool, |
| unsigned char** pp, unsigned int* psize, |
| unsigned int* pentries) const |
| { |
| gold_assert(this->is_finalized_); |
| gold_assert(!this->needs_.empty()); |
| |
| const int verneed_size = elfcpp::Elf_sizes<size>::verneed_size; |
| const int vernaux_size = elfcpp::Elf_sizes<size>::vernaux_size; |
| |
| unsigned int sz = 0; |
| for (Needs::const_iterator p = this->needs_.begin(); |
| p != this->needs_.end(); |
| ++p) |
| { |
| sz += verneed_size; |
| sz += (*p)->count_versions() * vernaux_size; |
| } |
| |
| unsigned char* pbuf = new unsigned char[sz]; |
| |
| unsigned char* pb = pbuf; |
| Needs::const_iterator p; |
| unsigned int i; |
| for (p = this->needs_.begin(), i = 0; |
| p != this->needs_.end(); |
| ++p, ++i) |
| pb = (*p)->write<size, big_endian>(dynpool, |
| i + 1 >= this->needs_.size(), |
| pb); |
| |
| gold_assert(static_cast<unsigned int>(pb - pbuf) == sz); |
| |
| *pp = pbuf; |
| *psize = sz; |
| *pentries = this->needs_.size(); |
| } |
| |
| // Instantiate the templates we need. We could use the configure |
| // script to restrict this to only the ones for implemented targets. |
| |
| #ifdef HAVE_TARGET_32_LITTLE |
| template |
| class Sized_dynobj<32, false>; |
| #endif |
| |
| #ifdef HAVE_TARGET_32_BIG |
| template |
| class Sized_dynobj<32, true>; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_LITTLE |
| template |
| class Sized_dynobj<64, false>; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_BIG |
| template |
| class Sized_dynobj<64, true>; |
| #endif |
| |
| #ifdef HAVE_TARGET_32_LITTLE |
| template |
| void |
| Versions::symbol_section_contents<32, false>( |
| const Symbol_table*, |
| const Stringpool*, |
| unsigned int, |
| const std::vector<Symbol*>&, |
| unsigned char**, |
| unsigned int*) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_32_BIG |
| template |
| void |
| Versions::symbol_section_contents<32, true>( |
| const Symbol_table*, |
| const Stringpool*, |
| unsigned int, |
| const std::vector<Symbol*>&, |
| unsigned char**, |
| unsigned int*) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_LITTLE |
| template |
| void |
| Versions::symbol_section_contents<64, false>( |
| const Symbol_table*, |
| const Stringpool*, |
| unsigned int, |
| const std::vector<Symbol*>&, |
| unsigned char**, |
| unsigned int*) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_BIG |
| template |
| void |
| Versions::symbol_section_contents<64, true>( |
| const Symbol_table*, |
| const Stringpool*, |
| unsigned int, |
| const std::vector<Symbol*>&, |
| unsigned char**, |
| unsigned int*) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_32_LITTLE |
| template |
| void |
| Versions::def_section_contents<32, false>( |
| const Stringpool*, |
| unsigned char**, |
| unsigned int*, |
| unsigned int*) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_32_BIG |
| template |
| void |
| Versions::def_section_contents<32, true>( |
| const Stringpool*, |
| unsigned char**, |
| unsigned int*, |
| unsigned int*) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_LITTLE |
| template |
| void |
| Versions::def_section_contents<64, false>( |
| const Stringpool*, |
| unsigned char**, |
| unsigned int*, |
| unsigned int*) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_BIG |
| template |
| void |
| Versions::def_section_contents<64, true>( |
| const Stringpool*, |
| unsigned char**, |
| unsigned int*, |
| unsigned int*) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_32_LITTLE |
| template |
| void |
| Versions::need_section_contents<32, false>( |
| const Stringpool*, |
| unsigned char**, |
| unsigned int*, |
| unsigned int*) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_32_BIG |
| template |
| void |
| Versions::need_section_contents<32, true>( |
| const Stringpool*, |
| unsigned char**, |
| unsigned int*, |
| unsigned int*) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_LITTLE |
| template |
| void |
| Versions::need_section_contents<64, false>( |
| const Stringpool*, |
| unsigned char**, |
| unsigned int*, |
| unsigned int*) const; |
| #endif |
| |
| #ifdef HAVE_TARGET_64_BIG |
| template |
| void |
| Versions::need_section_contents<64, true>( |
| const Stringpool*, |
| unsigned char**, |
| unsigned int*, |
| unsigned int*) const; |
| #endif |
| |
| } // End namespace gold. |