1 files changed, 200 insertions, 0 deletions
diff --git a/toolkit/crashreporter/google-breakpad/src/common/linux/file_id.cc b/toolkit/crashreporter/google-breakpad/src/common/linux/file_id.cc
new file mode 100644
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+++ b/toolkit/crashreporter/google-breakpad/src/common/linux/file_id.cc
@@ -0,0 +1,200 @@
+// 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 <string>
+
+#include "common/linux/elf_gnu_compat.h"
+#include "common/linux/elfutils.h"
+#include "common/linux/linux_libc_support.h"
+#include "common/linux/memory_mapped_file.h"
+#include "common/using_std_string.h"
+#include "third_party/lss/linux_syscall_support.h"
+
+namespace google_breakpad {
+
+// Used in a few places for backwards-compatibility.
+const size_t kMDGUIDSize = sizeof(MDGUID);
+
+FileID::FileID(const char* path) : path_(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.
+
+static bool ElfClassBuildIDNoteIdentifier(const void *section, size_t length,
+                                          wasteful_vector<uint8_t>& identifier) {
+  static_assert(sizeof(ElfClass32::Nhdr) == sizeof(ElfClass64::Nhdr),
+                "Elf32_Nhdr and Elf64_Nhdr should be the same");
+  typedef typename ElfClass32::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 uint8_t* build_id = reinterpret_cast<const uint8_t*>(note_header) +
+    sizeof(Nhdr) + NOTE_PADDING(note_header->n_namesz);
+  identifier.insert(identifier.end(),
+                    build_id,
+                    build_id + note_header->n_descsz);
+
+  return true;
+}
+
+// Attempt to locate a .note.gnu.build-id section in an ELF binary
+// and copy it into |identifier|.
+static bool FindElfBuildIDNote(const void* elf_mapped_base,
+                               wasteful_vector<uint8_t>& identifier) {
+  PageAllocator allocator;
+  // lld normally creates 2 PT_NOTEs, gold normally creates 1.
+  auto_wasteful_vector<ElfSegment, 2> segs(&allocator);
+  if (FindElfSegments(elf_mapped_base, PT_NOTE, &segs)) {
+    for (ElfSegment& seg : segs) {
+      if (ElfClassBuildIDNoteIdentifier(seg.start, seg.size, identifier)) {
+        return true;
+      }
+    }
+  }
+
+  void* note_section;
+  size_t note_size;
+  if (FindElfSection(elf_mapped_base, ".note.gnu.build-id", SHT_NOTE,
+                     (const void**)&note_section, &note_size)) {
+    return ElfClassBuildIDNoteIdentifier(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,
+                               wasteful_vector<uint8_t>& identifier) {
+  void* text_section;
+  size_t text_size;
+  if (!FindElfSection(elf_mapped_base, ".text", SHT_PROGBITS,
+                      (const void**)&text_section, &text_size) ||
+      text_size == 0) {
+    return false;
+  }
+
+  // Only provide |kMDGUIDSize| bytes to keep identifiers produced by this
+  // function backwards-compatible.
+  identifier.resize(kMDGUIDSize);
+  my_memset(&identifier[0], 0, kMDGUIDSize);
+  const uint8_t* ptr = reinterpret_cast<const uint8_t*>(text_section);
+  const uint8_t* ptr_end = ptr + std::min(text_size, static_cast<size_t>(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,
+                                             wasteful_vector<uint8_t>& identifier) {
+  // 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(wasteful_vector<uint8_t>& identifier) {
+  MemoryMappedFile mapped_file(path_.c_str(), 0);
+  if (!mapped_file.data())  // Should probably check if size >= ElfW(Ehdr)?
+    return false;
+
+  return ElfFileIdentifierFromMappedFile(mapped_file.data(), identifier);
+}
+
+// These three functions are not ever called in an unsafe context, so it's OK
+// to allocate memory and use libc.
+static string bytes_to_hex_string(const uint8_t* bytes, size_t count) {
+  string result;
+  for (unsigned int idx = 0; idx < count; ++idx) {
+    char buf[3];
+    snprintf(buf, sizeof(buf), "%02X", bytes[idx]);
+    result.append(buf);
+  }
+  return result;
+}
+
+// static
+string FileID::ConvertIdentifierToUUIDString(
+    const wasteful_vector<uint8_t>& identifier) {
+  uint8_t identifier_swapped[kMDGUIDSize] = { 0 };
+
+  // Endian-ness swap to match dump processor expectation.
+  memcpy(identifier_swapped, &identifier[0],
+         std::min(kMDGUIDSize, identifier.size()));
+  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);
+
+  return bytes_to_hex_string(identifier_swapped, kMDGUIDSize);
+}
+
+// static
+string FileID::ConvertIdentifierToString(
+    const wasteful_vector<uint8_t>& identifier) {
+  return bytes_to_hex_string(&identifier[0], identifier.size());
+}
+
+}  // namespace google_breakpad