diff options
| -rw-r--r-- | gold/ChangeLog | 15 | ||||
| -rw-r--r-- | gold/layout.cc | 216 | ||||
| -rw-r--r-- | gold/layout.h | 15 | ||||
| -rw-r--r-- | gold/options.h | 4 |
4 files changed, 230 insertions, 20 deletions
diff --git a/gold/ChangeLog b/gold/ChangeLog index af137fc..8b75a4a 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,5 +1,20 @@ 2008-03-24 Ian Lance Taylor <iant@google.com> + * options.h (class General_options): Define build_id option. + * layout.h (class Layout): Declare write_build_id, create_note, + create_build_id. Add build_id_note_ member. + * layout.cc: Include <cerrno>, <fcntl.h>, <unistd.h>, + "libiberty.h", "md5.h", "sha1.h". + (Layout::Layout): Initialize eh_frame_data_, + eh_frame_hdr_section_, and build_id_note_. + (Layout::finalize): Call create_build_id. + (Layout::create_note): New function, broken out of + Layout::create_gold_note. + (Layout::create_gold_note): Call create_note. + (Layout::create_build_id): New function. + (Layout::write_build_id): New function. + (Close_task_runner::run): Call write_build_id. + * x86_64.cc: Correct license to GPLv3. 2008-03-23 Ian Lance Taylor <iant@google.com> diff --git a/gold/layout.cc b/gold/layout.cc index 9758597..1bbfcb6 100644 --- a/gold/layout.cc +++ b/gold/layout.cc @@ -22,10 +22,16 @@ #include "gold.h" +#include <cerrno> #include <cstring> #include <algorithm> #include <iostream> #include <utility> +#include <fcntl.h> +#include <unistd.h> +#include "libiberty.h" +#include "md5.h" +#include "sha1.h" #include "parameters.h" #include "options.h" @@ -76,7 +82,8 @@ Layout::Layout(const General_options& options, Script_options* script_options) unattached_section_list_(), special_output_list_(), section_headers_(NULL), tls_segment_(NULL), symtab_section_(NULL), dynsym_section_(NULL), dynamic_section_(NULL), dynamic_data_(NULL), - eh_frame_section_(NULL), group_signatures_(), output_file_size_(-1), + eh_frame_section_(NULL), eh_frame_data_(NULL), eh_frame_hdr_section_(NULL), + build_id_note_(NULL), group_signatures_(), output_file_size_(-1), input_requires_executable_stack_(false), input_with_gnu_stack_note_(false), input_without_gnu_stack_note_(false), @@ -1035,6 +1042,7 @@ Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab, this->create_gold_note(); this->create_executable_stack_info(target); + this->create_build_id(); Output_segment* phdr_seg = NULL; if (!parameters->options().relocatable() && !parameters->doing_static_link()) @@ -1181,15 +1189,16 @@ Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab, return off; } -// Create a .note section for an executable or shared library. This -// records the version of gold used to create the binary. +// Create a note header following the format defined in the ELF ABI. +// NAME is the name, NOTE_TYPE is the type, DESCSZ is the size of the +// descriptor. ALLOCATE is true if the section should be allocated in +// memory. This returns the new note section. It sets +// *TRAILING_PADDING to the number of trailing zero bytes required. -void -Layout::create_gold_note() +Output_section* +Layout::create_note(const char* name, int note_type, size_t descsz, + bool allocate, size_t* trailing_padding) { - if (parameters->options().relocatable()) - return; - // Authorities all agree that the values in a .note field should // be aligned on 4-byte boundaries for 32-bit binaries. However, // they differ on what the alignment is for 64-bit binaries. @@ -1208,19 +1217,14 @@ Layout::create_gold_note() #endif // The contents of the .note section. - const char* name = "GNU"; - std::string desc(std::string("gold ") + gold::get_version_string()); size_t namesz = strlen(name) + 1; size_t aligned_namesz = align_address(namesz, size / 8); - size_t descsz = desc.length() + 1; size_t aligned_descsz = align_address(descsz, size / 8); - const int note_type = 4; - size_t notesz = 3 * (size / 8) + aligned_namesz + aligned_descsz; + size_t notehdrsz = 3 * (size / 8) + aligned_namesz; - unsigned char buffer[128]; - gold_assert(sizeof buffer >= notesz); - memset(buffer, 0, notesz); + unsigned char* buffer = new unsigned char[notehdrsz]; + memset(buffer, 0, notehdrsz); bool is_big_endian = parameters->target().is_big_endian(); @@ -1258,15 +1262,46 @@ Layout::create_gold_note() gold_unreachable(); memcpy(buffer + 3 * (size / 8), name, namesz); - memcpy(buffer + 3 * (size / 8) + aligned_namesz, desc.data(), descsz); const char* note_name = this->namepool_.add(".note", false, NULL); + elfcpp::Elf_Xword flags = 0; + if (allocate) + flags = elfcpp::SHF_ALLOC; Output_section* os = this->make_output_section(note_name, elfcpp::SHT_NOTE, - 0); - Output_section_data* posd = new Output_data_const(buffer, notesz, - size / 8); + flags); + Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz, + size / 8); + os->add_output_section_data(posd); + + *trailing_padding = aligned_descsz - descsz; + + return os; +} + +// For an executable or shared library, create a note to record the +// version of gold used to create the binary. + +void +Layout::create_gold_note() +{ + if (parameters->options().relocatable()) + return; + + std::string desc = std::string("gold ") + gold::get_version_string(); + + size_t trailing_padding; + Output_section *os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION, + desc.size(), false, &trailing_padding); + + Output_section_data* posd = new Output_data_const(desc, 4); os->add_output_section_data(posd); + + if (trailing_padding > 0) + { + posd = new Output_data_fixed_space(trailing_padding, 0); + os->add_output_section_data(posd); + } } // Record whether the stack should be executable. This can be set @@ -1318,6 +1353,104 @@ Layout::create_executable_stack_info(const Target* target) } } +// If --build-id was used, set up the build ID note. + +void +Layout::create_build_id() +{ + if (!parameters->options().user_set_build_id()) + return; + + const char* style = parameters->options().build_id(); + if (strcmp(style, "none") == 0) + return; + + // Set DESCSZ to the size of the note descriptor. When possible, + // set DESC to the note descriptor contents. + size_t descsz; + std::string desc; + if (strcmp(style, "md5") == 0) + descsz = 128 / 8; + else if (strcmp(style, "sha1") == 0) + descsz = 160 / 8; + else if (strcmp(style, "uuid") == 0) + { + const size_t uuidsz = 128 / 8; + + char buffer[uuidsz]; + memset(buffer, 0, uuidsz); + + int descriptor = ::open("/dev/urandom", O_RDONLY); + if (descriptor < 0) + gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"), + strerror(errno)); + else + { + ssize_t got = ::read(descriptor, buffer, uuidsz); + ::close(descriptor); + if (got < 0) + gold_error(_("/dev/urandom: read failed: %s"), strerror(errno)); + else if (static_cast<size_t>(got) != uuidsz) + gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"), + uuidsz, got); + } + + desc.assign(buffer, uuidsz); + descsz = uuidsz; + } + else if (strncmp(style, "0x", 2) == 0) + { + hex_init(); + const char* p = style + 2; + while (*p != '\0') + { + if (hex_p(p[0]) && hex_p(p[1])) + { + char c = (hex_value(p[0]) << 4) | hex_value(p[1]); + desc += c; + p += 2; + } + else if (*p == '-' || *p == ':') + ++p; + else + gold_fatal(_("--build-id argument '%s' not a valid hex number"), + style); + } + descsz = desc.size(); + } + else + gold_fatal(_("unrecognized --build-id argument '%s'"), style); + + // Create the note. + size_t trailing_padding; + Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID, + descsz, true, &trailing_padding); + + if (!desc.empty()) + { + // We know the value already, so we fill it in now. + gold_assert(desc.size() == descsz); + + Output_section_data* posd = new Output_data_const(desc, 4); + os->add_output_section_data(posd); + + if (trailing_padding != 0) + { + posd = new Output_data_fixed_space(trailing_padding, 0); + os->add_output_section_data(posd); + } + } + else + { + // We need to compute a checksum after we have completed the + // link. + gold_assert(trailing_padding == 0); + this->build_id_note_ = new Output_data_fixed_space(descsz, 4); + os->add_output_section_data(this->build_id_note_); + os->set_after_input_sections(); + } +} + // Return whether SEG1 should be before SEG2 in the output file. This // is based entirely on the segment type and flags. When this is // called the segment addresses has normally not yet been set. @@ -2676,6 +2809,46 @@ Layout::write_sections_after_input_sections(Output_file* of) this->section_headers_->write(of); } +// If the build ID requires computing a checksum, do so here, and +// write it out. We compute a checksum over the entire file because +// that is simplest. + +void +Layout::write_build_id(Output_file* of) const +{ + if (this->build_id_note_ == NULL) + return; + + const unsigned char* iv = of->get_input_view(0, this->output_file_size_); + + unsigned char* ov = of->get_output_view(this->build_id_note_->offset(), + this->build_id_note_->data_size()); + + const char* style = parameters->options().build_id(); + if (strcmp(style, "sha1") == 0) + { + sha1_ctx ctx; + sha1_init_ctx(&ctx); + sha1_process_bytes(iv, this->output_file_size_, &ctx); + sha1_finish_ctx(&ctx, ov); + } + else if (strcmp(style, "md5") == 0) + { + md5_ctx ctx; + md5_init_ctx(&ctx); + md5_process_bytes(iv, this->output_file_size_, &ctx); + md5_finish_ctx(&ctx, ov); + } + else + gold_unreachable(); + + of->write_output_view(this->build_id_note_->offset(), + this->build_id_note_->data_size(), + ov); + + of->free_input_view(0, this->output_file_size_, iv); +} + // Write out a binary file. This is called after the link is // complete. IN is the temporary output file we used to generate the // ELF code. We simply walk through the segments, read them from @@ -2856,6 +3029,9 @@ Write_after_input_sections_task::run(Workqueue*) void Close_task_runner::run(Workqueue*, const Task*) { + // If we need to compute a checksum for the BUILD if, we do so here. + this->layout_->write_build_id(this->of_); + // If we've been asked to create a binary file, we do so here. if (this->options_->oformat_enum() != General_options::OBJECT_FORMAT_ELF) this->layout_->write_binary(this->of_); diff --git a/gold/layout.h b/gold/layout.h index 714c374..fe888c7 100644 --- a/gold/layout.h +++ b/gold/layout.h @@ -294,6 +294,10 @@ class Layout script_options() const { return this->script_options_; } + // Compute and write out the build ID if needed. + void + write_build_id(Output_file*) const; + // Rewrite output file in binary format. void write_binary(Output_file* in) const; @@ -370,6 +374,11 @@ class Layout }; typedef std::vector<Group_signature> Group_signatures; + // Create a .note section, filling in the header. + Output_section* + create_note(const char* name, int note_type, size_t descsz, + bool allocate, size_t* trailing_padding); + // Create a .note section for gold. void create_gold_note(); @@ -378,6 +387,10 @@ class Layout void create_executable_stack_info(const Target*); + // Create a build ID note if needed. + void + create_build_id(); + // Find the first read-only PT_LOAD segment, creating one if // necessary. Output_segment* @@ -586,6 +599,8 @@ class Layout Eh_frame* eh_frame_data_; // The exception frame header output section if there is one. Output_section* eh_frame_hdr_section_; + // The space for the build ID checksum if there is one. + Output_section_data* build_id_note_; // A list of group sections and their signatures. Group_signatures group_signatures_; // The size of the output file. diff --git a/gold/options.h b/gold/options.h index a9b546b..b95a705 100644 --- a/gold/options.h +++ b/gold/options.h @@ -460,6 +460,10 @@ class General_options DEFINE_bool(Bsymbolic, options::ONE_DASH, '\0', false, N_("Bind defined symbols locally"), NULL); + DEFINE_optional_string(build_id, options::TWO_DASHES, '\0', "sha1", + N_("Generate build ID note"), + N_("[=STYLE]")); + #ifdef HAVE_ZLIB_H DEFINE_enum(compress_debug_sections, options::TWO_DASHES, '\0', "none", N_("Compress .debug_* sections in the output file"), |