diff options
Diffstat (limited to 'gold/layout.cc')
| -rw-r--r-- | gold/layout.cc | 175 |
1 files changed, 174 insertions, 1 deletions
diff --git a/gold/layout.cc b/gold/layout.cc index 2eb7b7c..9ce38c3 100644 --- a/gold/layout.cc +++ b/gold/layout.cc @@ -474,7 +474,8 @@ Layout::Layout(int number_of_input_files, Script_options* script_options) input_section_position_(), input_section_glob_(), incremental_base_(NULL), - free_list_() + free_list_(), + gnu_properties_() { // Make space for more than enough segments for a typical file. // This is just for efficiency--it's OK if we wind up needing more. @@ -2193,11 +2194,133 @@ Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags, } } +// Read a value with given size and endianness. + +static inline uint64_t +read_sized_value(size_t size, const unsigned char* buf, bool is_big_endian, + const Object* object) +{ + uint64_t val = 0; + if (size == 4) + { + if (is_big_endian) + val = elfcpp::Swap<32, true>::readval(buf); + else + val = elfcpp::Swap<32, false>::readval(buf); + } + else if (size == 8) + { + if (is_big_endian) + val = elfcpp::Swap<64, true>::readval(buf); + else + val = elfcpp::Swap<64, false>::readval(buf); + } + else + { + gold_warning(_("%s: in .note.gnu.properties section, " + "pr_datasz must be 4 or 8"), + object->name().c_str()); + } + return val; +} + +// Write a value with given size and endianness. + +static inline void +write_sized_value(uint64_t value, size_t size, unsigned char* buf, + bool is_big_endian) +{ + if (size == 4) + { + if (is_big_endian) + elfcpp::Swap<32, true>::writeval(buf, static_cast<uint32_t>(value)); + else + elfcpp::Swap<32, false>::writeval(buf, static_cast<uint32_t>(value)); + } + else if (size == 8) + { + if (is_big_endian) + elfcpp::Swap<64, true>::writeval(buf, value); + else + elfcpp::Swap<64, false>::writeval(buf, value); + } + else + { + // We will have already complained about this. + } +} + +// Handle the .note.gnu.property section at layout time. + +void +Layout::layout_gnu_property(unsigned int note_type, + unsigned int pr_type, + size_t pr_datasz, + const unsigned char* pr_data, + const Object* object) +{ + // We currently support only the one note type. + gold_assert(note_type == elfcpp::NT_GNU_PROPERTY_TYPE_0); + + Gnu_properties::iterator pprop = this->gnu_properties_.find(pr_type); + if (pprop == this->gnu_properties_.end()) + { + Gnu_property prop; + prop.pr_datasz = pr_datasz; + prop.pr_data = new unsigned char[pr_datasz]; + memcpy(prop.pr_data, pr_data, pr_datasz); + this->gnu_properties_[pr_type] = prop; + } + else + { + if (pr_type >= elfcpp::GNU_PROPERTY_LOPROC + && pr_type < elfcpp::GNU_PROPERTY_HIPROC) + { + // Target-dependent property value; call the target to merge. + parameters->target().merge_gnu_property(note_type, + pr_type, + pr_datasz, + pr_data, + pprop->second.pr_datasz, + pprop->second.pr_data, + object); + } + else + { + const bool is_big_endian = parameters->target().is_big_endian(); + switch (pr_type) + { + case elfcpp::GNU_PROPERTY_STACK_SIZE: + // Record the maximum value seen. + { + uint64_t val1 = read_sized_value(pprop->second.pr_datasz, + pprop->second.pr_data, + is_big_endian, object); + uint64_t val2 = read_sized_value(pr_datasz, pr_data, + is_big_endian, object); + if (val2 > val1) + write_sized_value(val2, pprop->second.pr_datasz, + pprop->second.pr_data, is_big_endian); + } + break; + case elfcpp::GNU_PROPERTY_NO_COPY_ON_PROTECTED: + // No data to merge. + break; + default: + gold_warning(_("%s: unknown program property type %d " + "in .note.gnu.properties section"), + object->name().c_str(), pr_type); + } + } + } +} + // Create automatic note sections. void Layout::create_notes() { + this->create_gnu_properties_note(); this->create_gold_note(); this->create_stack_segment(); this->create_build_id(); @@ -3021,6 +3144,56 @@ Layout::create_note(const char* name, int note_type, return os; } +// Create a .note.gnu.properties section to record program properties +// accumulated from the input files. + +void +Layout::create_gnu_properties_note() +{ + if (this->gnu_properties_.empty()) + return; + + const unsigned int size = parameters->target().get_size(); + const bool is_big_endian = parameters->target().is_big_endian(); + + // Compute the total size of the properties array. + size_t descsz = 0; + for (Gnu_properties::const_iterator prop = this->gnu_properties_.begin(); + prop != this->gnu_properties_.end(); + ++prop) + { + descsz = align_address(descsz + 8 + prop->second.pr_datasz, size / 8); + } + + // Create the note section. + size_t trailing_padding; + Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_PROPERTY_TYPE_0, + ".note.gnu.properties", descsz, + true, &trailing_padding); + if (os == NULL) + return; + gold_assert(trailing_padding == 0); + + // Allocate and fill the properties array. + unsigned char* desc = new unsigned char[descsz]; + unsigned char* p = desc; + for (Gnu_properties::const_iterator prop = this->gnu_properties_.begin(); + prop != this->gnu_properties_.end(); + ++prop) + { + size_t datasz = prop->second.pr_datasz; + size_t aligned_datasz = align_address(prop->second.pr_datasz, size / 8); + write_sized_value(prop->first, 4, p, is_big_endian); + write_sized_value(datasz, 4, p + 4, is_big_endian); + memcpy(p + 8, prop->second.pr_data, datasz); + if (aligned_datasz > datasz) + memset(p + 8 + datasz, 0, aligned_datasz - datasz); + p += 8 + aligned_datasz; + } + Output_section_data* posd = new Output_data_const(desc, descsz, 4); + os->add_output_section_data(posd); +} + // For an executable or shared library, create a note to record the // version of gold used to create the binary. |