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// 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
#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