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Diffstat (limited to 'toolkit/crashreporter/breakpad-client/linux/minidump_writer/minidump_writer_unittest.cc')
| -rw-r--r-- | toolkit/crashreporter/breakpad-client/linux/minidump_writer/minidump_writer_unittest.cc | 934 |
1 files changed, 934 insertions, 0 deletions
diff --git a/toolkit/crashreporter/breakpad-client/linux/minidump_writer/minidump_writer_unittest.cc b/toolkit/crashreporter/breakpad-client/linux/minidump_writer/minidump_writer_unittest.cc new file mode 100644 index 0000000000..4e49a4e577 --- /dev/null +++ b/toolkit/crashreporter/breakpad-client/linux/minidump_writer/minidump_writer_unittest.cc @@ -0,0 +1,934 @@ +// Copyright (c) 2011 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. + +#include <fcntl.h> +#include <poll.h> +#include <sys/stat.h> +#include <sys/syscall.h> +#include <sys/types.h> +#include <ucontext.h> +#include <unistd.h> + +#include <string> + +#include "breakpad_googletest_includes.h" +#include "linux/handler/exception_handler.h" +#include "linux/minidump_writer/linux_dumper.h" +#include "linux/minidump_writer/minidump_writer.h" +#include "linux/minidump_writer/minidump_writer_unittest_utils.h" +#include "common/linux/breakpad_getcontext.h" +#include "common/linux/eintr_wrapper.h" +#include "common/linux/file_id.h" +#include "common/linux/ignore_ret.h" +#include "common/linux/safe_readlink.h" +#include "common/scoped_ptr.h" +#include "common/tests/auto_tempdir.h" +#include "common/tests/file_utils.h" +#include "common/using_std_string.h" +#include "google_breakpad/processor/minidump.h" + +using namespace google_breakpad; + +namespace { + +typedef testing::Test MinidumpWriterTest; + +const char kMDWriterUnitTestFileName[] = "/minidump-writer-unittest"; + +TEST(MinidumpWriterTest, SetupWithPath) { + int fds[2]; + ASSERT_NE(-1, pipe(fds)); + + 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_group); + } + close(fds[0]); + + ExceptionHandler::CrashContext context; + memset(&context, 0, sizeof(context)); + + AutoTempDir temp_dir; + string templ = temp_dir.path() + kMDWriterUnitTestFileName; + // Set a non-zero tid to avoid tripping asserts. + context.tid = child; + ASSERT_TRUE(WriteMinidump(templ.c_str(), child, &context, sizeof(context))); + struct stat st; + ASSERT_EQ(0, stat(templ.c_str(), &st)); + ASSERT_GT(st.st_size, 0); + + close(fds[1]); + IGNORE_EINTR(waitpid(child, nullptr, 0)); +} + +TEST(MinidumpWriterTest, SetupWithFD) { + int fds[2]; + ASSERT_NE(-1, pipe(fds)); + + const pid_t child = fork(); + if (child == 0) { + close(fds[1]); + char b; + HANDLE_EINTR(read(fds[0], &b, sizeof(b))); + close(fds[0]); + syscall(__NR_exit_group); + } + close(fds[0]); + + ExceptionHandler::CrashContext context; + memset(&context, 0, sizeof(context)); + + AutoTempDir temp_dir; + string templ = temp_dir.path() + kMDWriterUnitTestFileName; + int fd = open(templ.c_str(), O_CREAT | O_WRONLY, S_IRWXU); + // Set a non-zero tid to avoid tripping asserts. + context.tid = child; + ASSERT_TRUE(WriteMinidump(fd, child, &context, sizeof(context))); + struct stat st; + ASSERT_EQ(0, stat(templ.c_str(), &st)); + ASSERT_GT(st.st_size, 0); + + close(fds[1]); + IGNORE_EINTR(waitpid(child, nullptr, 0)); +} + +// Test that mapping info can be specified when writing a minidump, +// and that it ends up in the module list of the minidump. +TEST(MinidumpWriterTest, MappingInfo) { + int fds[2]; + ASSERT_NE(-1, pipe(fds)); + + // These are defined here so the parent can use them to check the + // data from the minidump afterwards. + const uint32_t memory_size = sysconf(_SC_PAGESIZE); + const char* kMemoryName = "a fake module"; + const uint8_t kModuleGUID[sizeof(MDGUID)] = { + 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, + 0x88, 0x99, 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF + }; + const string module_identifier = "33221100554477668899AABBCCDDEEFF0"; + + // Get some memory. + char* memory = + reinterpret_cast<char*>(mmap(NULL, + memory_size, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON, + -1, + 0)); + const uintptr_t kMemoryAddress = reinterpret_cast<uintptr_t>(memory); + ASSERT_TRUE(memory); + + 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_group); + } + close(fds[0]); + + ExceptionHandler::CrashContext context; + memset(&context, 0, sizeof(context)); + ASSERT_EQ(0, getcontext(&context.context)); + context.tid = child; + + AutoTempDir temp_dir; + string templ = temp_dir.path() + kMDWriterUnitTestFileName; + + // Add information about the mapped memory. + MappingInfo info; + info.start_addr = kMemoryAddress; + info.size = memory_size; + info.offset = 0; + info.exec = false; + strcpy(info.name, kMemoryName); + + MappingList mappings; + AppMemoryList memory_list; + MappingEntry mapping; + mapping.first = info; + mapping.second.assign(std::begin(kModuleGUID), std::end(kModuleGUID)); + mappings.push_back(mapping); + ASSERT_TRUE(WriteMinidump(templ.c_str(), child, &context, sizeof(context), + mappings, memory_list, false, 0, false)); + + // Read the minidump. Load the module list, and ensure that + // the mmap'ed |memory| is listed with the given module name + // and debug ID. + Minidump minidump(templ); + ASSERT_TRUE(minidump.Read()); + + MinidumpModuleList* module_list = minidump.GetModuleList(); + ASSERT_TRUE(module_list); + const MinidumpModule* module = + module_list->GetModuleForAddress(kMemoryAddress); + ASSERT_TRUE(module); + + EXPECT_EQ(kMemoryAddress, module->base_address()); + EXPECT_EQ(memory_size, module->size()); + EXPECT_EQ(kMemoryName, module->code_file()); + EXPECT_EQ(module_identifier, module->debug_identifier()); + + uint32_t len; + // These streams are expected to be there + EXPECT_TRUE(minidump.SeekToStreamType(MD_THREAD_LIST_STREAM, &len)); + EXPECT_TRUE(minidump.SeekToStreamType(MD_MEMORY_LIST_STREAM, &len)); + EXPECT_TRUE(minidump.SeekToStreamType(MD_EXCEPTION_STREAM, &len)); + EXPECT_TRUE(minidump.SeekToStreamType(MD_SYSTEM_INFO_STREAM, &len)); + EXPECT_TRUE(minidump.SeekToStreamType(MD_LINUX_CPU_INFO, &len)); + EXPECT_TRUE(minidump.SeekToStreamType(MD_LINUX_PROC_STATUS, &len)); + EXPECT_TRUE(minidump.SeekToStreamType(MD_LINUX_CMD_LINE, &len)); + EXPECT_TRUE(minidump.SeekToStreamType(MD_LINUX_ENVIRON, &len)); + EXPECT_TRUE(minidump.SeekToStreamType(MD_LINUX_AUXV, &len)); + EXPECT_TRUE(minidump.SeekToStreamType(MD_LINUX_MAPS, &len)); + EXPECT_TRUE(minidump.SeekToStreamType(MD_LINUX_DSO_DEBUG, &len)); + + close(fds[1]); + IGNORE_EINTR(waitpid(child, nullptr, 0)); +} + +// Test that minidumping is skipped while writing minidumps if principal mapping +// is not referenced. +TEST(MinidumpWriterTest, MinidumpSkippedIfRequested) { + int fds[2]; + ASSERT_NE(-1, pipe(fds)); + + 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_group); + } + close(fds[0]); + + ExceptionHandler::CrashContext context; + memset(&context, 0, sizeof(context)); + ASSERT_EQ(0, getcontext(&context.context)); + context.tid = child; + + AutoTempDir temp_dir; + string templ = temp_dir.path() + kMDWriterUnitTestFileName; + + // pass an invalid principal mapping address, which will force + // WriteMinidump to not write a minidump. + ASSERT_FALSE(WriteMinidump(templ.c_str(), child, &context, sizeof(context), + true, static_cast<uintptr_t>(0x0102030405060708ull), + false)); + close(fds[1]); + IGNORE_EINTR(waitpid(child, nullptr, 0)); +} + +// Test that minidumping is skipped while writing minidumps if principal mapping +// is not referenced. +TEST(MinidumpWriterTest, MinidumpStacksSkippedIfRequested) { + int fds[2]; + ASSERT_NE(-1, pipe(fds)); + + const pid_t child = fork(); + if (child == 0) { + close(fds[1]); + + // Create a thread that does not return, and only references libc (not the + // current executable). This thread should not be captured in the minidump. + pthread_t thread; + pthread_attr_t thread_attributes; + pthread_attr_init(&thread_attributes); + pthread_attr_setdetachstate(&thread_attributes, PTHREAD_CREATE_DETACHED); + sigset_t sigset; + sigemptyset(&sigset); + pthread_create(&thread, &thread_attributes, + reinterpret_cast<void* (*)(void*)>(&sigsuspend), &sigset); + + char b; + IGNORE_RET(HANDLE_EINTR(read(fds[0], &b, sizeof(b)))); + close(fds[0]); + syscall(__NR_exit_group); + } + close(fds[0]); + + ExceptionHandler::CrashContext context; + memset(&context, 0, sizeof(context)); + ASSERT_EQ(0, getcontext(&context.context)); + context.tid = child; + + AutoTempDir temp_dir; + string templ = temp_dir.path() + kMDWriterUnitTestFileName; + + // Pass an invalid principal mapping address, which will force + // WriteMinidump to not dump any thread stacks. + ASSERT_TRUE(WriteMinidump( + templ.c_str(), child, &context, sizeof(context), true, + reinterpret_cast<uintptr_t>(google_breakpad::WriteFile), false)); + + // Read the minidump. And ensure that thread memory was dumped only for the + // main thread. + Minidump minidump(templ); + ASSERT_TRUE(minidump.Read()); + + MinidumpThreadList *threads = minidump.GetThreadList(); + int threads_with_stacks = 0; + for (unsigned int i = 0; i < threads->thread_count(); ++i) { + MinidumpThread *thread = threads->GetThreadAtIndex(i); + if (thread->GetMemory()) { + ++threads_with_stacks; + } + } +#if defined(THREAD_SANITIZER) || defined(ADDRESS_SANITIZER) + ASSERT_GE(threads_with_stacks, 1); +#else + ASSERT_EQ(threads_with_stacks, 1); +#endif + close(fds[1]); + IGNORE_EINTR(waitpid(child, nullptr, 0)); +} + +// Test that stacks can be sanitized while writing minidumps. +TEST(MinidumpWriterTest, StacksAreSanitizedIfRequested) { + int fds[2]; + ASSERT_NE(-1, pipe(fds)); + + 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_group); + } + close(fds[0]); + + ExceptionHandler::CrashContext context; + memset(&context, 0, sizeof(context)); + ASSERT_EQ(0, getcontext(&context.context)); + context.tid = child; + + AutoTempDir temp_dir; + string templ = temp_dir.path() + kMDWriterUnitTestFileName; + // pass an invalid principal mapping address, which will force + // WriteMinidump to not dump any thread stacks. + ASSERT_TRUE(WriteMinidump(templ.c_str(), child, &context, sizeof(context), + false, 0, true)); + + // Read the minidump. And ensure that thread memory contains a defaced value. + Minidump minidump(templ); + ASSERT_TRUE(minidump.Read()); + + const uintptr_t defaced = +#if defined(__LP64__) + 0x0defaced0defaced; +#else + 0x0defaced; +#endif + MinidumpThreadList *threads = minidump.GetThreadList(); + for (unsigned int i = 0; i < threads->thread_count(); ++i) { + MinidumpThread *thread = threads->GetThreadAtIndex(i); + MinidumpMemoryRegion *mem = thread->GetMemory(); + ASSERT_TRUE(mem != nullptr); + uint32_t sz = mem->GetSize(); + const uint8_t *data = mem->GetMemory(); + ASSERT_TRUE(memmem(data, sz, &defaced, sizeof(defaced)) != nullptr); + } + close(fds[1]); + IGNORE_EINTR(waitpid(child, nullptr, 0)); +} + +// Test that a binary with a longer-than-usual build id note +// makes its way all the way through to the minidump unscathed. +// The linux_client_unittest is linked with an explicit --build-id +// in Makefile.am. +TEST(MinidumpWriterTest, BuildIDLong) { + int fds[2]; + ASSERT_NE(-1, pipe(fds)); + + 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_group); + } + close(fds[0]); + + ExceptionHandler::CrashContext context; + memset(&context, 0, sizeof(context)); + ASSERT_EQ(0, getcontext(&context.context)); + context.tid = child; + + AutoTempDir temp_dir; + const string dump_path = temp_dir.path() + kMDWriterUnitTestFileName; + + EXPECT_TRUE(WriteMinidump(dump_path.c_str(), + child, &context, sizeof(context))); + close(fds[1]); + + // Read the minidump. Load the module list, and ensure that + // the main module has the correct debug id and code id. + Minidump minidump(dump_path); + ASSERT_TRUE(minidump.Read()); + + MinidumpModuleList* module_list = minidump.GetModuleList(); + ASSERT_TRUE(module_list); + const MinidumpModule* module = module_list->GetMainModule(); + ASSERT_TRUE(module); + const string module_identifier = "030201000504070608090A0B0C0D0E0F0"; + // This is passed explicitly to the linker in Makefile.am + const string build_id = + "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f"; + EXPECT_EQ(module_identifier, module->debug_identifier()); + EXPECT_EQ(build_id, module->code_identifier()); + + IGNORE_EINTR(waitpid(child, nullptr, 0)); +} + +// Test that mapping info can be specified, and that it overrides +// existing mappings that are wholly contained within the specified +// range. +TEST(MinidumpWriterTest, MappingInfoContained) { + int fds[2]; + ASSERT_NE(-1, pipe(fds)); + + // These are defined here so the parent can use them to check the + // data from the minidump afterwards. + const int32_t memory_size = sysconf(_SC_PAGESIZE); + const char* kMemoryName = "a fake module"; + const uint8_t kModuleGUID[sizeof(MDGUID)] = { + 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, + 0x88, 0x99, 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF + }; + const string module_identifier = "33221100554477668899AABBCCDDEEFF0"; + + // mmap a file + AutoTempDir temp_dir; + string tempfile = temp_dir.path() + "/minidump-writer-unittest-temp"; + int fd = open(tempfile.c_str(), O_RDWR | O_CREAT, 0); + ASSERT_NE(-1, fd); + unlink(tempfile.c_str()); + // fill with zeros + google_breakpad::scoped_array<char> buffer(new char[memory_size]); + memset(buffer.get(), 0, memory_size); + ASSERT_EQ(memory_size, write(fd, buffer.get(), memory_size)); + lseek(fd, 0, SEEK_SET); + + char* memory = + reinterpret_cast<char*>(mmap(NULL, + memory_size, + PROT_READ | PROT_WRITE, + MAP_PRIVATE, + fd, + 0)); + const uintptr_t kMemoryAddress = reinterpret_cast<uintptr_t>(memory); + ASSERT_TRUE(memory); + close(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_group); + } + close(fds[0]); + + ExceptionHandler::CrashContext context; + memset(&context, 0, sizeof(context)); + context.tid = 1; + + string dumpfile = temp_dir.path() + kMDWriterUnitTestFileName; + + // Add information about the mapped memory. Report it as being larger than + // it actually is. + MappingInfo info; + info.start_addr = kMemoryAddress - memory_size; + info.size = memory_size * 3; + info.offset = 0; + info.exec = false; + strcpy(info.name, kMemoryName); + + MappingList mappings; + AppMemoryList memory_list; + MappingEntry mapping; + mapping.first = info; + mapping.second.assign(std::begin(kModuleGUID), std::end(kModuleGUID)); + mappings.push_back(mapping); + ASSERT_TRUE(WriteMinidump(dumpfile.c_str(), child, &context, sizeof(context), + mappings, memory_list)); + + // Read the minidump. Load the module list, and ensure that + // the mmap'ed |memory| is listed with the given module name + // and debug ID. + Minidump minidump(dumpfile); + ASSERT_TRUE(minidump.Read()); + + MinidumpModuleList* module_list = minidump.GetModuleList(); + ASSERT_TRUE(module_list); + const MinidumpModule* module = + module_list->GetModuleForAddress(kMemoryAddress); + ASSERT_TRUE(module); + + EXPECT_EQ(info.start_addr, module->base_address()); + EXPECT_EQ(info.size, module->size()); + EXPECT_EQ(kMemoryName, module->code_file()); + EXPECT_EQ(module_identifier, module->debug_identifier()); + + close(fds[1]); + IGNORE_EINTR(waitpid(child, nullptr, 0)); +} + +TEST(MinidumpWriterTest, DeletedBinary) { + const string kNumberOfThreadsArgument = "1"; + const string helper_path(GetHelperBinary()); + if (helper_path.empty()) { + FAIL() << "Couldn't find helper binary"; + exit(1); + } + + // Copy binary to a temp file. + AutoTempDir temp_dir; + string binpath = temp_dir.path() + "/linux-dumper-unittest-helper"; + ASSERT_TRUE(CopyFile(helper_path.c_str(), binpath.c_str())) + << "Failed to copy " << helper_path << " to " << binpath; + ASSERT_EQ(0, chmod(binpath.c_str(), 0755)); + + int fds[2]; + ASSERT_NE(-1, pipe(fds)); + + pid_t child_pid = fork(); + if (child_pid == 0) { + // In child process. + close(fds[0]); + + // Pass the pipe fd and the number of threads as arguments. + char pipe_fd_string[8]; + sprintf(pipe_fd_string, "%d", fds[1]); + execl(binpath.c_str(), + binpath.c_str(), + pipe_fd_string, + kNumberOfThreadsArgument.c_str(), + NULL); + } + close(fds[1]); + // Wait for the child process to signal that it's ready. + struct pollfd pfd; + memset(&pfd, 0, sizeof(pfd)); + pfd.fd = fds[0]; + pfd.events = POLLIN | POLLERR; + + const int r = HANDLE_EINTR(poll(&pfd, 1, 1000)); + ASSERT_EQ(1, r); + ASSERT_TRUE(pfd.revents & POLLIN); + uint8_t junk; + const int nr = HANDLE_EINTR(read(fds[0], &junk, sizeof(junk))); + ASSERT_EQ(static_cast<ssize_t>(sizeof(junk)), nr); + close(fds[0]); + + // Child is ready now. + // Unlink the test binary. + unlink(binpath.c_str()); + + ExceptionHandler::CrashContext context; + memset(&context, 0, sizeof(context)); + + string templ = temp_dir.path() + kMDWriterUnitTestFileName; + // Set a non-zero tid to avoid tripping asserts. + context.tid = child_pid; + ASSERT_TRUE(WriteMinidump(templ.c_str(), child_pid, &context, + sizeof(context))); + kill(child_pid, SIGKILL); + + struct stat st; + ASSERT_EQ(0, stat(templ.c_str(), &st)); + ASSERT_GT(st.st_size, 0); + + Minidump minidump(templ); + ASSERT_TRUE(minidump.Read()); + + // Check that the main module filename is correct. + MinidumpModuleList* module_list = minidump.GetModuleList(); + ASSERT_TRUE(module_list); + const MinidumpModule* module = module_list->GetMainModule(); + EXPECT_STREQ(binpath.c_str(), module->code_file().c_str()); + // Check that the file ID is correct. + FileID fileid(helper_path.c_str()); + PageAllocator allocator; + wasteful_vector<uint8_t> identifier(&allocator, kDefaultBuildIdSize); + EXPECT_TRUE(fileid.ElfFileIdentifier(identifier)); + string identifier_string = FileID::ConvertIdentifierToUUIDString(identifier); + string module_identifier(identifier_string); + // Strip out dashes + size_t pos; + while ((pos = module_identifier.find('-')) != string::npos) { + module_identifier.erase(pos, 1); + } + // And append a zero, because module IDs include an "age" field + // which is always zero on Linux. + module_identifier += "0"; + EXPECT_EQ(module_identifier, module->debug_identifier()); + + IGNORE_EINTR(waitpid(child_pid, nullptr, 0)); +} + +// Test that an additional memory region can be added to the minidump. +TEST(MinidumpWriterTest, AdditionalMemory) { + int fds[2]; + ASSERT_NE(-1, pipe(fds)); + + // These are defined here so the parent can use them to check the + // data from the minidump afterwards. + const uint32_t kMemorySize = sysconf(_SC_PAGESIZE); + + // Get some heap memory. + uint8_t* memory = new uint8_t[kMemorySize]; + const uintptr_t kMemoryAddress = reinterpret_cast<uintptr_t>(memory); + ASSERT_TRUE(memory); + + // Stick some data into the memory so the contents can be verified. + for (uint32_t i = 0; i < kMemorySize; ++i) { + memory[i] = i % 255; + } + + const pid_t child = fork(); + if (child == 0) { + close(fds[1]); + char b; + HANDLE_EINTR(read(fds[0], &b, sizeof(b))); + close(fds[0]); + syscall(__NR_exit_group); + } + close(fds[0]); + + ExceptionHandler::CrashContext context; + + // This needs a valid context for minidump writing to work, but getting + // a useful one from the child is too much work, so just use one from + // the parent since the child is just a forked copy anyway. + ASSERT_EQ(0, getcontext(&context.context)); + context.tid = child; + + AutoTempDir temp_dir; + string templ = temp_dir.path() + kMDWriterUnitTestFileName; + unlink(templ.c_str()); + + MappingList mappings; + AppMemoryList memory_list; + + // Add the memory region to the list of memory to be included. + AppMemory app_memory; + app_memory.ptr = memory; + app_memory.length = kMemorySize; + memory_list.push_back(app_memory); + ASSERT_TRUE(WriteMinidump(templ.c_str(), child, &context, sizeof(context), + mappings, memory_list)); + + // Read the minidump. Ensure that the memory region is present + Minidump minidump(templ); + ASSERT_TRUE(minidump.Read()); + + MinidumpMemoryList* dump_memory_list = minidump.GetMemoryList(); + ASSERT_TRUE(dump_memory_list); + const MinidumpMemoryRegion* region = + dump_memory_list->GetMemoryRegionForAddress(kMemoryAddress); + ASSERT_TRUE(region); + + EXPECT_EQ(kMemoryAddress, region->GetBase()); + EXPECT_EQ(kMemorySize, region->GetSize()); + + // Verify memory contents. + EXPECT_EQ(0, memcmp(region->GetMemory(), memory, kMemorySize)); + + delete[] memory; + close(fds[1]); + IGNORE_EINTR(waitpid(child, nullptr, 0)); +} + +// Test that an invalid thread stack pointer still results in a minidump. +TEST(MinidumpWriterTest, InvalidStackPointer) { + int fds[2]; + ASSERT_NE(-1, pipe(fds)); + + const pid_t child = fork(); + if (child == 0) { + close(fds[1]); + char b; + HANDLE_EINTR(read(fds[0], &b, sizeof(b))); + close(fds[0]); + syscall(__NR_exit_group); + } + close(fds[0]); + + ExceptionHandler::CrashContext context; + + // This needs a valid context for minidump writing to work, but getting + // a useful one from the child is too much work, so just use one from + // the parent since the child is just a forked copy anyway. + ASSERT_EQ(0, getcontext(&context.context)); + context.tid = child; + + // Fake the child's stack pointer for its crashing thread. NOTE: This must + // be an invalid memory address for the child process (stack or otherwise). + // Try 1MB below the current stack. + uintptr_t invalid_stack_pointer = + reinterpret_cast<uintptr_t>(&context) - 1024*1024; +#if defined(__i386) + context.context.uc_mcontext.gregs[REG_ESP] = invalid_stack_pointer; +#elif defined(__x86_64) + context.context.uc_mcontext.gregs[REG_RSP] = invalid_stack_pointer; +#elif defined(__ARM_EABI__) + context.context.uc_mcontext.arm_sp = invalid_stack_pointer; +#elif defined(__aarch64__) + context.context.uc_mcontext.sp = invalid_stack_pointer; +#elif defined(__mips__) + context.context.uc_mcontext.gregs[MD_CONTEXT_MIPS_REG_SP] = + invalid_stack_pointer; +#else +# error "This code has not been ported to your platform yet." +#endif + + AutoTempDir temp_dir; + string templ = temp_dir.path() + kMDWriterUnitTestFileName; + // NOTE: In previous versions of Breakpad, WriteMinidump() would fail if + // presented with an invalid stack pointer. + ASSERT_TRUE(WriteMinidump(templ.c_str(), child, &context, sizeof(context))); + + // Read the minidump. Ensure that the memory region is present + Minidump minidump(templ); + ASSERT_TRUE(minidump.Read()); + + // TODO(ted.mielczarek,mkrebs): Enable this part of the test once + // https://breakpad.appspot.com/413002/ is committed. +#if 0 + // Make sure there's a thread without a stack. NOTE: It's okay if + // GetThreadList() shows the error: "ERROR: MinidumpThread has a memory + // region problem". + MinidumpThreadList* dump_thread_list = minidump.GetThreadList(); + ASSERT_TRUE(dump_thread_list); + bool found_empty_stack = false; + for (int i = 0; i < dump_thread_list->thread_count(); i++) { + MinidumpThread* thread = dump_thread_list->GetThreadAtIndex(i); + ASSERT_TRUE(thread->thread() != NULL); + // When the stack size is zero bytes, GetMemory() returns NULL. + if (thread->GetMemory() == NULL) { + found_empty_stack = true; + break; + } + } + // NOTE: If you fail this, first make sure that "invalid_stack_pointer" + // above is indeed set to an invalid address. + ASSERT_TRUE(found_empty_stack); +#endif + + close(fds[1]); + IGNORE_EINTR(waitpid(child, nullptr, 0)); +} + +// Test that limiting the size of the minidump works. +TEST(MinidumpWriterTest, MinidumpSizeLimit) { + static const int kNumberOfThreadsInHelperProgram = 40; + + char number_of_threads_arg[3]; + sprintf(number_of_threads_arg, "%d", kNumberOfThreadsInHelperProgram); + + string helper_path(GetHelperBinary()); + if (helper_path.empty()) { + FAIL() << "Couldn't find helper binary"; + exit(1); + } + + int fds[2]; + ASSERT_NE(-1, pipe(fds)); + + pid_t child_pid = fork(); + if (child_pid == 0) { + // In child process. + close(fds[0]); + + // Pass the pipe fd and the number of threads as arguments. + char pipe_fd_string[8]; + sprintf(pipe_fd_string, "%d", fds[1]); + execl(helper_path.c_str(), + helper_path.c_str(), + pipe_fd_string, + number_of_threads_arg, + NULL); + } + close(fds[1]); + + // Wait for all child threads to indicate that they have started + for (int threads = 0; threads < kNumberOfThreadsInHelperProgram; threads++) { + struct pollfd pfd; + memset(&pfd, 0, sizeof(pfd)); + pfd.fd = fds[0]; + pfd.events = POLLIN | POLLERR; + + const int r = HANDLE_EINTR(poll(&pfd, 1, 1000)); + ASSERT_EQ(1, r); + ASSERT_TRUE(pfd.revents & POLLIN); + uint8_t junk; + ASSERT_EQ(read(fds[0], &junk, sizeof(junk)), + static_cast<ssize_t>(sizeof(junk))); + } + close(fds[0]); + + // There is a race here because we may stop a child thread before + // it is actually running the busy loop. Empirically this sleep + // is sufficient to avoid the race. + usleep(100000); + + // Child and its threads are ready now. + + + off_t normal_file_size; + int total_normal_stack_size = 0; + AutoTempDir temp_dir; + + // First, write a minidump with no size limit. + { + string normal_dump = temp_dir.path() + + "/minidump-writer-unittest.dmp"; + ASSERT_TRUE(WriteMinidump(normal_dump.c_str(), -1, + child_pid, NULL, 0, + MappingList(), AppMemoryList())); + struct stat st; + ASSERT_EQ(0, stat(normal_dump.c_str(), &st)); + ASSERT_GT(st.st_size, 0); + normal_file_size = st.st_size; + + Minidump minidump(normal_dump); + ASSERT_TRUE(minidump.Read()); + MinidumpThreadList* dump_thread_list = minidump.GetThreadList(); + ASSERT_TRUE(dump_thread_list); + for (unsigned int i = 0; i < dump_thread_list->thread_count(); i++) { + MinidumpThread* thread = dump_thread_list->GetThreadAtIndex(i); + ASSERT_TRUE(thread->thread() != NULL); + // When the stack size is zero bytes, GetMemory() returns NULL. + MinidumpMemoryRegion* memory = thread->GetMemory(); + ASSERT_TRUE(memory != NULL); + total_normal_stack_size += memory->GetSize(); + } + } + + // Second, write a minidump with a size limit big enough to not trigger + // anything. + { + // Set size limit arbitrarily 1MB larger than the normal file size -- such + // that the limiting code will not kick in. + const off_t minidump_size_limit = normal_file_size + 1024*1024; + + string same_dump = temp_dir.path() + + "/minidump-writer-unittest-same.dmp"; + ASSERT_TRUE(WriteMinidump(same_dump.c_str(), minidump_size_limit, + child_pid, NULL, 0, + MappingList(), AppMemoryList())); + struct stat st; + ASSERT_EQ(0, stat(same_dump.c_str(), &st)); + // Make sure limiting wasn't actually triggered. NOTE: If you fail this, + // first make sure that "minidump_size_limit" above is indeed set to a + // large enough value -- the limit-checking code in minidump_writer.cc + // does just a rough estimate. + ASSERT_EQ(normal_file_size, st.st_size); + } + + // Third, write a minidump with a size limit small enough to be triggered. + { + // Set size limit to some arbitrary amount, such that the limiting code + // will kick in. The equation used to set this value was determined by + // simply reversing the size-limit logic a little bit in order to pick a + // size we know will trigger it. The definition of + // kLimitAverageThreadStackLength here was copied from class + // MinidumpWriter in minidump_writer.cc. + static const unsigned kLimitAverageThreadStackLength = 8 * 1024; + off_t minidump_size_limit = kNumberOfThreadsInHelperProgram * + kLimitAverageThreadStackLength; + // If, in reality, each of the threads' stack is *smaller* than + // kLimitAverageThreadStackLength, the normal file size could very well be + // smaller than the arbitrary limit that was just set. In that case, + // either of these numbers should trigger the size-limiting code, but we + // might as well pick the smallest. + if (normal_file_size < minidump_size_limit) + minidump_size_limit = normal_file_size; + + string limit_dump = temp_dir.path() + + "/minidump-writer-unittest-limit.dmp"; + ASSERT_TRUE(WriteMinidump(limit_dump.c_str(), minidump_size_limit, + child_pid, NULL, 0, + MappingList(), AppMemoryList())); + struct stat st; + ASSERT_EQ(0, stat(limit_dump.c_str(), &st)); + ASSERT_GT(st.st_size, 0); + // Make sure the file size is at least smaller than the original. If this + // fails because it's the same size, then the size-limit logic didn't kick + // in like it was supposed to. + EXPECT_LT(st.st_size, normal_file_size); + + Minidump minidump(limit_dump); + ASSERT_TRUE(minidump.Read()); + MinidumpThreadList* dump_thread_list = minidump.GetThreadList(); + ASSERT_TRUE(dump_thread_list); + int total_limit_stack_size = 0; + for (unsigned int i = 0; i < dump_thread_list->thread_count(); i++) { + MinidumpThread* thread = dump_thread_list->GetThreadAtIndex(i); + ASSERT_TRUE(thread->thread() != NULL); + // When the stack size is zero bytes, GetMemory() returns NULL. + MinidumpMemoryRegion* memory = thread->GetMemory(); + ASSERT_TRUE(memory != NULL); + total_limit_stack_size += memory->GetSize(); + } + + // Make sure stack size shrunk by at least 1KB per extra thread. The + // definition of kLimitBaseThreadCount here was copied from class + // MinidumpWriter in minidump_writer.cc. + // Note: The 1KB is arbitrary, and assumes that the thread stacks are big + // enough to shrink by that much. For example, if each thread stack was + // originally only 2KB, the current size-limit logic wouldn't actually + // shrink them because that's the size to which it tries to shrink. If + // you fail this part of the test due to something like that, the test + // logic should probably be improved to account for your situation. + const unsigned kLimitBaseThreadCount = 20; + const unsigned kMinPerExtraThreadStackReduction = 1024; + const int min_expected_reduction = (kNumberOfThreadsInHelperProgram - + kLimitBaseThreadCount) * kMinPerExtraThreadStackReduction; + EXPECT_LT(total_limit_stack_size, + total_normal_stack_size - min_expected_reduction); + } + + // Kill the helper program. + kill(child_pid, SIGKILL); + IGNORE_EINTR(waitpid(child_pid, nullptr, 0)); +} + +} // namespace |