The Tor Browser: comparison toolkit/crashreporter/google-breakpad/src/common/linux/file

--1:000000000000
+:f92701aef706
+// Copyright (c) 2006, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// file_id.cc: Return a unique identifier for a file
+//
+// See file_id.h for documentation
+//
+#include "common/linux/file_id.h"
+#include <arpa/inet.h>
+#include <assert.h>
+#include <string.h>
+#include <algorithm>
+#include "common/linux/elfutils.h"
+#include "common/linux/linux_libc_support.h"
+#include "common/linux/memory_mapped_file.h"
+#include "third_party/lss/linux_syscall_support.h"
+namespace google_breakpad {
+#ifndef NT_GNU_BUILD_ID
+#define NT_GNU_BUILD_ID 3
+#endif
+FileID::FileID(const char* path) {
+strncpy(path_, path, sizeof(path_));
+}
+// ELF note name and desc are 32-bits word padded.
+#define NOTE_PADDING(a) ((a + 3) & ~3)
+// These functions are also used inside the crashed process, so be safe
+// and use the syscall/libc wrappers instead of direct syscalls or libc.
+template<typename ElfClass>
+static bool ElfClassBuildIDNoteIdentifier(const void *section, int length,
+uint8_t identifier[kMDGUIDSize]) {
+typedef typename ElfClass::Nhdr Nhdr;
+const void* section_end = reinterpret_cast<const char*>(section) + length;
+const Nhdr* note_header = reinterpret_cast<const Nhdr*>(section);
+while (reinterpret_cast<const void *>(note_header) < section_end) {
+if (note_header->n_type == NT_GNU_BUILD_ID)
+break;
+note_header = reinterpret_cast<const Nhdr*>(
+reinterpret_cast<const char*>(note_header) + sizeof(Nhdr) +
+NOTE_PADDING(note_header->n_namesz) +
+NOTE_PADDING(note_header->n_descsz));
+}
+if (reinterpret_cast<const void *>(note_header) >= section_end ||
+note_header->n_descsz == 0) {
+return false;
+}
+const char* build_id = reinterpret_cast<const char*>(note_header) +
+sizeof(Nhdr) + NOTE_PADDING(note_header->n_namesz);
+// Copy as many bits of the build ID as will fit
+// into the GUID space.
+my_memset(identifier, 0, kMDGUIDSize);
+memcpy(identifier, build_id,
+std::min(kMDGUIDSize, (size_t)note_header->n_descsz));
+return true;
+}
+// Attempt to locate a .note.gnu.build-id section in an ELF binary
+// and copy as many bytes of it as will fit into |identifier|.
+static bool FindElfBuildIDNote(const void *elf_mapped_base,
+uint8_t identifier[kMDGUIDSize]) {
+void* note_section;
+int note_size, elfclass;
+if ((!FindElfSegment(elf_mapped_base, PT_NOTE,
+(const void**)&note_section, &note_size, &elfclass) ||
+note_size == 0)  &&
+(!FindElfSection(elf_mapped_base, ".note.gnu.build-id", SHT_NOTE,
+(const void**)&note_section, &note_size, &elfclass) ||
+note_size == 0)) {
+return false;
+}
+if (elfclass == ELFCLASS32) {
+return ElfClassBuildIDNoteIdentifier<ElfClass32>(note_section, note_size,
+identifier);
+} else if (elfclass == ELFCLASS64) {
+return ElfClassBuildIDNoteIdentifier<ElfClass64>(note_section, note_size,
+identifier);
+}
+return false;
+}
+// Attempt to locate the .text section of an ELF binary and generate
+// a simple hash by XORing the first page worth of bytes into |identifier|.
+static bool HashElfTextSection(const void *elf_mapped_base,
+uint8_t identifier[kMDGUIDSize]) {
+void* text_section;
+int text_size;
+if (!FindElfSection(elf_mapped_base, ".text", SHT_PROGBITS,
+(const void**)&text_section, &text_size, NULL) ||
+text_size == 0) {
+return false;
+}
+my_memset(identifier, 0, kMDGUIDSize);
+const uint8_t* ptr = reinterpret_cast<const uint8_t*>(text_section);
+const uint8_t* ptr_end = ptr + std::min(text_size, 4096);
+while (ptr < ptr_end) {
+for (unsigned i = 0; i < kMDGUIDSize; i++)
+identifier[i] ^= ptr[i];
+ptr += kMDGUIDSize;
+}
+return true;
+}
+// static
+bool FileID::ElfFileIdentifierFromMappedFile(const void* base,
+uint8_t identifier[kMDGUIDSize]) {
+// Look for a build id note first.
+if (FindElfBuildIDNote(base, identifier))
+return true;
+// Fall back on hashing the first page of the text section.
+return HashElfTextSection(base, identifier);
+}
+bool FileID::ElfFileIdentifier(uint8_t identifier[kMDGUIDSize]) {
+MemoryMappedFile mapped_file(path_);
+if (!mapped_file.data())  // Should probably check if size >= ElfW(Ehdr)?
+return false;
+return ElfFileIdentifierFromMappedFile(mapped_file.data(), identifier);
+}
+// static
+void FileID::ConvertIdentifierToString(const uint8_t identifier[kMDGUIDSize],
+char* buffer, int buffer_length) {
+uint8_t identifier_swapped[kMDGUIDSize];
+// Endian-ness swap to match dump processor expectation.
+memcpy(identifier_swapped, identifier, kMDGUIDSize);
+uint32_t* data1 = reinterpret_cast<uint32_t*>(identifier_swapped);
+*data1 = htonl(*data1);
+uint16_t* data2 = reinterpret_cast<uint16_t*>(identifier_swapped + 4);
+*data2 = htons(*data2);
+uint16_t* data3 = reinterpret_cast<uint16_t*>(identifier_swapped + 6);
+*data3 = htons(*data3);
+int buffer_idx = 0;
+for (unsigned int idx = 0;
+(buffer_idx < buffer_length) && (idx < kMDGUIDSize);
+++idx) {
+int hi = (identifier_swapped[idx] >> 4) & 0x0F;
+int lo = (identifier_swapped[idx]) & 0x0F;
+if (idx == 4 || idx == 6 || idx == 8 || idx == 10)
+buffer[buffer_idx++] = '-';
+buffer[buffer_idx++] = (hi >= 10) ? 'A' + hi - 10 : '0' + hi;
+buffer[buffer_idx++] = (lo >= 10) ? 'A' + lo - 10 : '0' + lo;
+}
+// NULL terminate
+buffer[(buffer_idx < buffer_length) ? buffer_idx : buffer_idx - 1] = 0;
+}
+}  // namespace google_breakpad

The Tor Browser / file comparison

comparison: toolkit/crashreporter/google-breakpad/src/common/linux/file_id.cc

toolkit/crashreporter/google-breakpad/src/common/linux/file_id.cc