diff options
Diffstat (limited to 'gold/powerpc.cc')
| -rw-r--r-- | gold/powerpc.cc | 251 |
1 files changed, 247 insertions, 4 deletions
diff --git a/gold/powerpc.cc b/gold/powerpc.cc index a978e7a..b8ff86d 100644 --- a/gold/powerpc.cc +++ b/gold/powerpc.cc @@ -23,6 +23,7 @@ #include "gold.h" +#include <set> #include <algorithm> #include "elfcpp.h" #include "dwarf.h" @@ -320,6 +321,109 @@ private: }; template<int size, bool big_endian> +class Powerpc_dynobj : public Sized_dynobj<size, big_endian> +{ +public: + typedef typename elfcpp::Elf_types<size>::Elf_Addr Address; + + Powerpc_dynobj(const std::string& name, Input_file* input_file, off_t offset, + const typename elfcpp::Ehdr<size, big_endian>& ehdr) + : Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr), + opd_shndx_(0), opd_ent_() + { } + + ~Powerpc_dynobj() + { } + + // Call Sized_dynobj::do_read_symbols to read the symbols then + // read .opd from a dynamic object, filling in opd_ent_ vector, + void + do_read_symbols(Read_symbols_data*); + + // The .opd section shndx. + unsigned int + opd_shndx() const + { + return this->opd_shndx_; + } + + // The .opd section address. + Address + opd_address() const + { + return this->opd_address_; + } + + // Init OPD entry arrays. + void + init_opd(size_t opd_size) + { + size_t count = this->opd_ent_ndx(opd_size); + this->opd_ent_.resize(count); + } + + // Return section and offset of function entry for .opd + R_OFF. + unsigned int + get_opd_ent(Address r_off, Address* value = NULL) const + { + size_t ndx = this->opd_ent_ndx(r_off); + gold_assert(ndx < this->opd_ent_.size()); + gold_assert(this->opd_ent_[ndx].shndx != 0); + if (value != NULL) + *value = this->opd_ent_[ndx].off; + return this->opd_ent_[ndx].shndx; + } + + // Set section and offset of function entry for .opd + R_OFF. + void + set_opd_ent(Address r_off, unsigned int shndx, Address value) + { + size_t ndx = this->opd_ent_ndx(r_off); + gold_assert(ndx < this->opd_ent_.size()); + this->opd_ent_[ndx].shndx = shndx; + this->opd_ent_[ndx].off = value; + } + +private: + // Used to specify extent of executable sections. + struct Sec_info + { + Sec_info(Address start_, Address len_, unsigned int shndx_) + : start(start_), len(len_), shndx(shndx_) + { } + + bool + operator<(const Sec_info& that) const + { return this->start < that.start; } + + Address start; + Address len; + unsigned int shndx; + }; + + struct Opd_ent + { + unsigned int shndx; + Address off; + }; + + // Return index into opd_ent_ array for .opd entry at OFF. + size_t + opd_ent_ndx(size_t off) const + { return off >> 4;} + + // For 64-bit the .opd section shndx and address. + unsigned int opd_shndx_; + Address opd_address_; + + // The first 8-byte word of an OPD entry gives the address of the + // entry point of the function. Records the section and offset + // corresponding to the address. Note that in dynamic objects, + // offset is *not* relative to the section. + std::vector<Opd_ent> opd_ent_; +}; + +template<int size, bool big_endian> class Target_powerpc : public Sized_target<size, big_endian> { public: @@ -448,6 +552,9 @@ class Target_powerpc : public Sized_target<size, big_endian> int64_t do_tls_offset_for_global(Symbol* gsym, unsigned int got_indx) const; + void + do_function_location(Symbol_location*) const; + // Relocate a section. void relocate_section(const Relocate_info<size, big_endian>*, @@ -1518,8 +1625,9 @@ Powerpc_relobj<size, big_endian>::do_find_special_sections( section_size_type names_size = sd->section_names_size; const unsigned char* s; - s = this->find_shdr(pshdrs, size == 32 ? ".got2" : ".opd", - names, names_size, NULL); + s = this->template find_shdr<size, big_endian>(pshdrs, + size == 32 ? ".got2" : ".opd", + names, names_size, NULL); if (s != NULL) { unsigned int ndx = (s - pshdrs) / elfcpp::Elf_sizes<size>::shdr_size; @@ -1634,6 +1742,105 @@ Powerpc_relobj<size, big_endian>::do_read_relocs(Read_relocs_data* rd) } } +// Call Sized_dynobj::do_read_symbols to read the symbols then +// read .opd from a dynamic object, filling in opd_ent_ vector, + +template<int size, bool big_endian> +void +Powerpc_dynobj<size, big_endian>::do_read_symbols(Read_symbols_data* sd) +{ + Sized_dynobj<size, big_endian>::do_read_symbols(sd); + if (size == 64) + { + const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size; + const unsigned char* const pshdrs = sd->section_headers->data(); + const unsigned char* namesu = sd->section_names->data(); + const char* names = reinterpret_cast<const char*>(namesu); + const unsigned char* s = NULL; + const unsigned char* opd; + section_size_type opd_size; + + // Find and read .opd section. + while (1) + { + s = this->template find_shdr<size, big_endian>(pshdrs, ".opd", names, + sd->section_names_size, + s); + if (s == NULL) + return; + + typename elfcpp::Shdr<size, big_endian> shdr(s); + if (shdr.get_sh_type() == elfcpp::SHT_PROGBITS + && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0) + { + this->opd_shndx_ = (s - pshdrs) / shdr_size; + this->opd_address_ = shdr.get_sh_addr(); + opd_size = convert_to_section_size_type(shdr.get_sh_size()); + opd = this->get_view(shdr.get_sh_offset(), opd_size, + true, false); + break; + } + } + + // Build set of executable sections. + // Using a set is probably overkill. There is likely to be only + // a few executable sections, typically .init, .text and .fini, + // and they are generally grouped together. + typedef std::set<Sec_info> Exec_sections; + Exec_sections exec_sections; + s = pshdrs; + for (unsigned int i = 1; i < this->shnum(); ++i, s += shdr_size) + { + typename elfcpp::Shdr<size, big_endian> shdr(s); + if (shdr.get_sh_type() == elfcpp::SHT_PROGBITS + && ((shdr.get_sh_flags() + & (elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR)) + == (elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR)) + && shdr.get_sh_size() != 0) + { + exec_sections.insert(Sec_info(shdr.get_sh_addr(), + shdr.get_sh_size(), i)); + } + } + if (exec_sections.empty()) + return; + + // Look over the OPD entries. This is complicated by the fact + // that some binaries will use two-word entries while others + // will use the standard three-word entries. In most cases + // the third word (the environment pointer for languages like + // Pascal) is unused and will be zero. If the third word is + // used it should not be pointing into executable sections, + // I think. + this->init_opd(opd_size); + for (const unsigned char* p = opd; p < opd + opd_size; p += 8) + { + typedef typename elfcpp::Swap<64, big_endian>::Valtype Valtype; + const Valtype* valp = reinterpret_cast<const Valtype*>(p); + Valtype val = elfcpp::Swap<64, big_endian>::readval(valp); + if (val == 0) + // Chances are that this is the third word of an OPD entry. + continue; + typename Exec_sections::const_iterator e + = exec_sections.upper_bound(Sec_info(val, 0, 0)); + if (e != exec_sections.begin()) + { + --e; + if (e->start <= val && val < e->start + e->len) + { + // We have an address in an executable section. + // VAL ought to be the function entry, set it up. + this->set_opd_ent(p - opd, e->shndx, val); + // Skip second word of OPD entry, the TOC pointer. + p += 8; + } + } + // If we didn't match any executable sections, we likely + // have a non-zero third word in the OPD entry. + } + } +} + // Set up some symbols. template<int size, bool big_endian> @@ -1706,8 +1913,8 @@ Target_powerpc<size, big_endian>::do_make_elf_object( } else if (et == elfcpp::ET_DYN) { - Sized_dynobj<size, big_endian>* obj = - new Sized_dynobj<size, big_endian>(name, input_file, offset, ehdr); + Powerpc_dynobj<size, big_endian>* obj = + new Powerpc_dynobj<size, big_endian>(name, input_file, offset, ehdr); obj->setup(); return obj; } @@ -5581,6 +5788,42 @@ Target_powerpc<size, big_endian>::do_gc_mark_symbol( } } +// For a symbol location in .opd, set LOC to the location of the +// function entry. + +template<int size, bool big_endian> +void +Target_powerpc<size, big_endian>::do_function_location( + Symbol_location* loc) const +{ + if (size == 64) + { + if (loc->object->is_dynamic()) + { + Powerpc_dynobj<size, big_endian>* ppc_object + = static_cast<Powerpc_dynobj<size, big_endian>*>(loc->object); + if (loc->shndx == ppc_object->opd_shndx()) + { + Address dest_off; + Address off = loc->offset - ppc_object->opd_address(); + loc->shndx = ppc_object->get_opd_ent(off, &dest_off); + loc->offset = dest_off; + } + } + else + { + const Powerpc_relobj<size, big_endian>* ppc_object + = static_cast<const Powerpc_relobj<size, big_endian>*>(loc->object); + if (loc->shndx == ppc_object->opd_shndx()) + { + Address dest_off; + loc->shndx = ppc_object->get_opd_ent(loc->offset, &dest_off); + loc->offset = dest_off; + } + } + } +} + // Scan relocations for a section. template<int size, bool big_endian> |