client/linux/microdump_writer/microdump_writer_unittest.cc

// Copyright (c) 2014 Google Inc.
// All rights reserved.
//
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// 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
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//
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#include <ctype.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

#include <sstream>
#include <string>

#include "breakpad_googletest_includes.h"
#include "client/linux/handler/exception_handler.h"
#include "client/linux/microdump_writer/microdump_writer.h"
#include "common/linux/eintr_wrapper.h"
#include "common/linux/ignore_ret.h"
#include "common/scoped_ptr.h"
#include "common/tests/auto_tempdir.h"
#include "common/using_std_string.h"

using namespace google_breakpad;

namespace {

typedef testing::Test MicrodumpWriterTest;

void CrashAndGetMicrodump(
    const MappingList& mappings,
    const char* build_fingerprint,
    const char* product_info,
    scoped_array<char>* buf) {
  int fds[2];
  ASSERT_NE(-1, pipe(fds));

  AutoTempDir temp_dir;
  string stderr_file = temp_dir.path() + "/stderr.log";
  int err_fd = open(stderr_file.c_str(), O_CREAT | O_RDWR, S_IRUSR | S_IWUSR);
  ASSERT_NE(-1, err_fd);

  const pid_t child = fork();
  if (child == 0) {
    close(fds[1]);
    char b;
    IGNORE_RET(HANDLE_EINTR(read(fds[0], &b, sizeof(b))));
    close(fds[0]);
    syscall(__NR_exit);
  }
  close(fds[0]);

  ExceptionHandler::CrashContext context;
  memset(&context, 0, sizeof(context));

  // Set a non-zero tid to avoid tripping asserts.
  context.tid = child;

  // Redirect temporarily stderr to the stderr.log file.
  int save_err = dup(STDERR_FILENO);
  ASSERT_NE(-1, save_err);
  ASSERT_NE(-1, dup2(err_fd, STDERR_FILENO));

  ASSERT_TRUE(WriteMicrodump(child, &context, sizeof(context), mappings,
      build_fingerprint, product_info));

  // Revert stderr back to the console.
  dup2(save_err, STDERR_FILENO);
  close(save_err);

  // Read back the stderr file and check for the microdump marker.
  fsync(err_fd);
  lseek(err_fd, 0, SEEK_SET);
  const size_t kBufSize = 64 * 1024;
  buf->reset(new char[kBufSize]);
  ASSERT_GT(read(err_fd, buf->get(), kBufSize), 0);

  close(err_fd);
  close(fds[1]);

  ASSERT_NE(static_cast<char*>(0), strstr(
      buf->get(), "-----BEGIN BREAKPAD MICRODUMP-----"));
  ASSERT_NE(static_cast<char*>(0), strstr(
      buf->get(), "-----END BREAKPAD MICRODUMP-----"));
}

void CheckMicrodumpContents(const string &microdum_content,
                            const string &expected_fingerprint,
                            const string &expected_product_info) {
  std::istringstream iss(microdum_content);
  bool did_find_os_info = false;
  bool did_find_product_info = false;
  for (string line; std::getline(iss, line);) {
    if (line.find("O ") == 0) {
      std::istringstream os_info_tokens(line);
      string token;
      os_info_tokens.ignore(2); // Ignore the "O " preamble.
      // Check the OS descriptor char (L=Linux, A=Android).
      os_info_tokens >> token;
      ASSERT_TRUE(token == "L" || token == "A");

      os_info_tokens >> token; // HW architecture.
      os_info_tokens >> token; // Number of cpus.
      for (size_t i = 0; i < token.size(); ++i)
        ASSERT_TRUE(isxdigit(token[i]));
      os_info_tokens >> token; // SW architecture.

      // Check that the build fingerprint is in the right place.
      os_info_tokens >> token;
      ASSERT_EQ(expected_fingerprint, token);
      did_find_os_info = true;
    } else if (line.find("V ") == 0) {
      ASSERT_EQ("V " + expected_product_info, line);
      did_find_product_info = true;
    }
  }
  ASSERT_TRUE(did_find_os_info);
  ASSERT_TRUE(did_find_product_info);
}

TEST(MicrodumpWriterTest, BasicWithMappings) {
  // Push some extra mapping to check the MappingList logic.
  const uint32_t memory_size = sysconf(_SC_PAGESIZE);
  const char* kMemoryName = "libfoo.so";
  const uint8_t kModuleGUID[sizeof(MDGUID)] = {
     0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
     0x88, 0x99, 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF
  };

  MappingInfo info;
  info.start_addr = memory_size;
  info.size = memory_size;
  info.offset = 42;
  strcpy(info.name, kMemoryName);

  MappingList mappings;
  MappingEntry mapping;
  mapping.first = info;
  memcpy(mapping.second, kModuleGUID, sizeof(MDGUID));
  mappings.push_back(mapping);

  scoped_array<char> buf;
  CrashAndGetMicrodump(mappings, NULL, NULL, &buf);

#ifdef __LP64__
  ASSERT_NE(static_cast<char*>(0), strstr(
      buf.get(), "M 0000000000001000 000000000000002A 0000000000001000 "
      "33221100554477668899AABBCCDDEEFF0 libfoo.so"));
#else
  ASSERT_NE(static_cast<char*>(0), strstr(
      buf.get(), "M 00001000 0000002A 00001000 "
      "33221100554477668899AABBCCDDEEFF0 libfoo.so"));
#endif

  // In absence of a product info in the minidump, the writer should just write
  // an unknown marker.
  ASSERT_NE(static_cast<char*>(0), strstr(
      buf.get(), "V UNKNOWN:0.0.0.0"));
}

// Ensure that the product info and build fingerprint metadata show up in the
// final microdump if present.
TEST(MicrodumpWriterTest, BuildFingerprintAndProductInfo) {
  const char kProductInfo[] = "MockProduct:42.0.2311.99";
  const char kBuildFingerprint[] =
      "aosp/occam/mako:5.1.1/LMY47W/12345678:userdegbug/dev-keys";
  scoped_array<char> buf;
  MappingList no_mappings;

  CrashAndGetMicrodump(no_mappings, kBuildFingerprint, kProductInfo, &buf);
  CheckMicrodumpContents(string(buf.get()), kBuildFingerprint, kProductInfo);
}

TEST(MicrodumpWriterTest, NoProductInfo) {
  const char kBuildFingerprint[] = "foobar";
  scoped_array<char> buf;
  MappingList no_mappings;

  CrashAndGetMicrodump(no_mappings, kBuildFingerprint, NULL, &buf);
  CheckMicrodumpContents(string(buf.get()), kBuildFingerprint, "UNKNOWN:0.0.0.0");
}
}  // namespace