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// Copyright (c) 2010 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 <poll.h>
#include <pthread.h>
#include <stdint.h>
#include <unistd.h>
#include <signal.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/wait.h>
#if defined(__mips__)
#include <sys/cachectl.h>
#endif
#include <string>
#include "breakpad_googletest_includes.h"
#include "linux/handler/exception_handler.h"
#include "linux/minidump_writer/minidump_writer.h"
#include "common/linux/eintr_wrapper.h"
#include "common/linux/ignore_ret.h"
#include "common/linux/linux_libc_support.h"
#include "common/tests/auto_tempdir.h"
#include "common/using_std_string.h"
#include "third_party/lss/linux_syscall_support.h"
#include "google_breakpad/processor/minidump.h"
using namespace google_breakpad;
namespace {
// Flush the instruction cache for a given memory range.
// Only required on ARM and mips.
void FlushInstructionCache(const char* memory, uint32_t memory_size) {
#if defined(__arm__)
long begin = reinterpret_cast<long>(memory);
long end = begin + static_cast<long>(memory_size);
# if defined(__ANDROID__)
// Provided by Android's <unistd.h>
cacheflush(begin, end, 0);
# elif defined(__linux__)
// GLibc/ARM doesn't provide a wrapper for it, do a direct syscall.
# ifndef __ARM_NR_cacheflush
# define __ARM_NR_cacheflush 0xf0002
# endif
syscall(__ARM_NR_cacheflush, begin, end, 0);
# else
# error "Your operating system is not supported yet"
# endif
#elif defined(__mips__)
# if defined(__ANDROID__)
// Provided by Android's <unistd.h>
long begin = reinterpret_cast<long>(memory);
long end = begin + static_cast<long>(memory_size);
#if _MIPS_SIM == _ABIO32
cacheflush(begin, end, 0);
#else
syscall(__NR_cacheflush, begin, end, ICACHE);
#endif
# elif defined(__linux__)
cacheflush(const_cast<char*>(memory), memory_size, ICACHE);
# else
# error "Your operating system is not supported yet"
# endif
#endif
}
void sigchld_handler(int signo) { }
int CreateTMPFile(const string& dir, string* path) {
string file = dir + "/exception-handler-unittest.XXXXXX";
const char* c_file = file.c_str();
// Copy that string, mkstemp needs a C string it can modify.
char* c_path = strdup(c_file);
const int fd = mkstemp(c_path);
if (fd >= 0)
*path = c_path;
free(c_path);
return fd;
}
class ExceptionHandlerTest : public ::testing::Test {
protected:
void SetUp() {
// We need to be able to wait for children, so SIGCHLD cannot be SIG_IGN.
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = sigchld_handler;
ASSERT_NE(sigaction(SIGCHLD, &sa, &old_action), -1);
}
void TearDown() {
sigaction(SIGCHLD, &old_action, NULL);
}
struct sigaction old_action;
};
void WaitForProcessToTerminate(pid_t process_id, int expected_status) {
int status;
ASSERT_NE(HANDLE_EINTR(waitpid(process_id, &status, 0)), -1);
ASSERT_TRUE(WIFSIGNALED(status));
ASSERT_EQ(expected_status, WTERMSIG(status));
}
// Reads the minidump path sent over the pipe |fd| and sets it in |path|.
void ReadMinidumpPathFromPipe(int fd, string* path) {
struct pollfd pfd;
memset(&pfd, 0, sizeof(pfd));
pfd.fd = fd;
pfd.events = POLLIN | POLLERR;
const int r = HANDLE_EINTR(poll(&pfd, 1, 0));
ASSERT_EQ(1, r);
ASSERT_TRUE(pfd.revents & POLLIN);
int32_t len;
ASSERT_EQ(static_cast<ssize_t>(sizeof(len)), read(fd, &len, sizeof(len)));
ASSERT_LT(len, 2048);
char* filename = static_cast<char*>(malloc(len + 1));
ASSERT_EQ(len, read(fd, filename, len));
filename[len] = 0;
close(fd);
*path = filename;
free(filename);
}
} // namespace
TEST(ExceptionHandlerTest, SimpleWithPath) {
AutoTempDir temp_dir;
ExceptionHandler handler(
MinidumpDescriptor(temp_dir.path()), NULL, NULL, NULL, true, -1);
EXPECT_EQ(temp_dir.path(), handler.minidump_descriptor().directory());
string temp_subdir = temp_dir.path() + "/subdir";
handler.set_minidump_descriptor(MinidumpDescriptor(temp_subdir));
EXPECT_EQ(temp_subdir, handler.minidump_descriptor().directory());
}
TEST(ExceptionHandlerTest, SimpleWithFD) {
AutoTempDir temp_dir;
string path;
const int fd = CreateTMPFile(temp_dir.path(), &path);
ExceptionHandler handler(MinidumpDescriptor(fd), NULL, NULL, NULL, true, -1);
close(fd);
}
static bool DoneCallback(const MinidumpDescriptor& descriptor,
void* context,
bool succeeded) {
if (!succeeded)
return false;
if (!descriptor.IsFD()) {
int fd = reinterpret_cast<intptr_t>(context);
uint32_t len = 0;
len = my_strlen(descriptor.path());
IGNORE_RET(HANDLE_EINTR(sys_write(fd, &len, sizeof(len))));
IGNORE_RET(HANDLE_EINTR(sys_write(fd, descriptor.path(), len)));
}
return true;
}
#ifndef ADDRESS_SANITIZER
// This is a replacement for "*reinterpret_cast<volatile int*>(NULL) = 0;"
// It is needed because GCC is allowed to assume that the program will
// not execute any undefined behavior (UB) operation. Further, when GCC
// observes that UB statement is reached, it can assume that all statements
// leading to the UB one are never executed either, and can completely
// optimize them out. In the case of ExceptionHandlerTest::ExternalDumper,
// GCC-4.9 optimized out the entire set up of ExceptionHandler, causing
// test failure.
volatile int *p_null; // external linkage, so GCC can't tell that it
// remains NULL. Volatile just for a good measure.
static void DoNullPointerDereference() {
*p_null = 1;
}
void ChildCrash(bool use_fd) {
AutoTempDir temp_dir;
int fds[2] = {0};
int minidump_fd = -1;
string minidump_path;
if (use_fd) {
minidump_fd = CreateTMPFile(temp_dir.path(), &minidump_path);
} else {
ASSERT_NE(pipe(fds), -1);
}
const pid_t child = fork();
if (child == 0) {
{
google_breakpad::scoped_ptr<ExceptionHandler> handler;
if (use_fd) {
handler.reset(new ExceptionHandler(MinidumpDescriptor(minidump_fd),
NULL, NULL, NULL, true, -1));
} else {
close(fds[0]); // Close the reading end.
void* fd_param = reinterpret_cast<void*>(fds[1]);
handler.reset(new ExceptionHandler(MinidumpDescriptor(temp_dir.path()),
NULL, DoneCallback, fd_param,
true, -1));
}
// Crash with the exception handler in scope.
DoNullPointerDereference();
}
}
if (!use_fd)
close(fds[1]); // Close the writting end.
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV));
if (!use_fd)
ASSERT_NO_FATAL_FAILURE(ReadMinidumpPathFromPipe(fds[0], &minidump_path));
struct stat st;
ASSERT_EQ(0, stat(minidump_path.c_str(), &st));
ASSERT_GT(st.st_size, 0);
unlink(minidump_path.c_str());
}
TEST(ExceptionHandlerTest, ChildCrashWithPath) {
ASSERT_NO_FATAL_FAILURE(ChildCrash(false));
}
TEST(ExceptionHandlerTest, ChildCrashWithFD) {
ASSERT_NO_FATAL_FAILURE(ChildCrash(true));
}
#if !defined(__ANDROID_API__) || __ANDROID_API__ >= __ANDROID_API_N__
static void* SleepFunction(void* unused) {
while (true) usleep(1000000);
return NULL;
}
static void* CrashFunction(void* b_ptr) {
pthread_barrier_t* b = reinterpret_cast<pthread_barrier_t*>(b_ptr);
pthread_barrier_wait(b);
DoNullPointerDereference();
return NULL;
}
// Tests that concurrent crashes do not enter a loop by alternately triggering
// the signal handler.
TEST(ExceptionHandlerTest, ParallelChildCrashesDontHang) {
AutoTempDir temp_dir;
const pid_t child = fork();
if (child == 0) {
google_breakpad::scoped_ptr<ExceptionHandler> handler(
new ExceptionHandler(MinidumpDescriptor(temp_dir.path()), NULL, NULL,
NULL, true, -1));
// We start a number of threads to make sure handling the signal takes
// enough time for the second thread to enter the signal handler.
int num_sleep_threads = 100;
google_breakpad::scoped_array<pthread_t> sleep_threads(
new pthread_t[num_sleep_threads]);
for (int i = 0; i < num_sleep_threads; ++i) {
ASSERT_EQ(0, pthread_create(&sleep_threads[i], NULL, SleepFunction,
NULL));
}
int num_crash_threads = 2;
google_breakpad::scoped_array<pthread_t> crash_threads(
new pthread_t[num_crash_threads]);
// Barrier to synchronize crashing both threads at the same time.
pthread_barrier_t b;
ASSERT_EQ(0, pthread_barrier_init(&b, NULL, num_crash_threads + 1));
for (int i = 0; i < num_crash_threads; ++i) {
ASSERT_EQ(0, pthread_create(&crash_threads[i], NULL, CrashFunction, &b));
}
pthread_barrier_wait(&b);
for (int i = 0; i < num_crash_threads; ++i) {
ASSERT_EQ(0, pthread_join(crash_threads[i], NULL));
}
}
// Wait a while until the child should have crashed.
usleep(1000000);
// Kill the child if it is still running.
kill(child, SIGKILL);
// If the child process terminated by itself, it will have returned SIGSEGV.
// If however it got stuck in a loop, it will have been killed by the
// SIGKILL.
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV));
}
#endif // !defined(__ANDROID_API__) || __ANDROID_API__ >= __ANDROID_API_N__
static bool DoneCallbackReturnFalse(const MinidumpDescriptor& descriptor,
void* context,
bool succeeded) {
return false;
}
static bool DoneCallbackReturnTrue(const MinidumpDescriptor& descriptor,
void* context,
bool succeeded) {
return true;
}
static bool DoneCallbackRaiseSIGKILL(const MinidumpDescriptor& descriptor,
void* context,
bool succeeded) {
raise(SIGKILL);
return true;
}
static bool FilterCallbackReturnFalse(void* context) {
return false;
}
static bool FilterCallbackReturnTrue(void* context) {
return true;
}
// SIGKILL cannot be blocked and a handler cannot be installed for it. In the
// following tests, if the child dies with signal SIGKILL, then the signal was
// redelivered to this handler. If the child dies with SIGSEGV then it wasn't.
static void RaiseSIGKILL(int sig) {
raise(SIGKILL);
}
static bool InstallRaiseSIGKILL() {
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = RaiseSIGKILL;
return sigaction(SIGSEGV, &sa, NULL) != -1;
}
static void CrashWithCallbacks(ExceptionHandler::FilterCallback filter,
ExceptionHandler::MinidumpCallback done,
string path) {
ExceptionHandler handler(
MinidumpDescriptor(path), filter, done, NULL, true, -1);
// Crash with the exception handler in scope.
DoNullPointerDereference();
}
TEST(ExceptionHandlerTest, RedeliveryOnFilterCallbackFalse) {
AutoTempDir temp_dir;
const pid_t child = fork();
if (child == 0) {
ASSERT_TRUE(InstallRaiseSIGKILL());
CrashWithCallbacks(FilterCallbackReturnFalse, NULL, temp_dir.path());
}
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGKILL));
}
TEST(ExceptionHandlerTest, RedeliveryOnDoneCallbackFalse) {
AutoTempDir temp_dir;
const pid_t child = fork();
if (child == 0) {
ASSERT_TRUE(InstallRaiseSIGKILL());
CrashWithCallbacks(NULL, DoneCallbackReturnFalse, temp_dir.path());
}
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGKILL));
}
TEST(ExceptionHandlerTest, NoRedeliveryOnDoneCallbackTrue) {
AutoTempDir temp_dir;
const pid_t child = fork();
if (child == 0) {
ASSERT_TRUE(InstallRaiseSIGKILL());
CrashWithCallbacks(NULL, DoneCallbackReturnTrue, temp_dir.path());
}
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV));
}
TEST(ExceptionHandlerTest, NoRedeliveryOnFilterCallbackTrue) {
AutoTempDir temp_dir;
const pid_t child = fork();
if (child == 0) {
ASSERT_TRUE(InstallRaiseSIGKILL());
CrashWithCallbacks(FilterCallbackReturnTrue, NULL, temp_dir.path());
}
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV));
}
TEST(ExceptionHandlerTest, RedeliveryToDefaultHandler) {
AutoTempDir temp_dir;
const pid_t child = fork();
if (child == 0) {
// Custom signal handlers, which may have been installed by a test launcher,
// are undesirable in this child.
signal(SIGSEGV, SIG_DFL);
CrashWithCallbacks(FilterCallbackReturnFalse, NULL, temp_dir.path());
}
// As RaiseSIGKILL wasn't installed, the redelivery should just kill the child
// with SIGSEGV.
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV));
}
// Check that saving and restoring the signal handler with 'signal'
// instead of 'sigaction' doesn't make the Breakpad signal handler
// crash. See comments in ExceptionHandler::SignalHandler for full
// details.
TEST(ExceptionHandlerTest, RedeliveryOnBadSignalHandlerFlag) {
AutoTempDir temp_dir;
const pid_t child = fork();
if (child == 0) {
// Install the RaiseSIGKILL handler for SIGSEGV.
ASSERT_TRUE(InstallRaiseSIGKILL());
// Create a new exception handler, this installs a new SIGSEGV
// handler, after saving the old one.
ExceptionHandler handler(
MinidumpDescriptor(temp_dir.path()), NULL,
DoneCallbackReturnFalse, NULL, true, -1);
// Install the default SIGSEGV handler, saving the current one.
// Then re-install the current one with 'signal', this loses the
// SA_SIGINFO flag associated with the Breakpad handler.
sighandler_t old_handler = signal(SIGSEGV, SIG_DFL);
ASSERT_NE(reinterpret_cast<void*>(old_handler),
reinterpret_cast<void*>(SIG_ERR));
ASSERT_NE(reinterpret_cast<void*>(signal(SIGSEGV, old_handler)),
reinterpret_cast<void*>(SIG_ERR));
// Crash with the exception handler in scope.
DoNullPointerDereference();
}
// SIGKILL means Breakpad's signal handler didn't crash.
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGKILL));
}
TEST(ExceptionHandlerTest, StackedHandlersDeliveredToTop) {
AutoTempDir temp_dir;
const pid_t child = fork();
if (child == 0) {
ExceptionHandler bottom(MinidumpDescriptor(temp_dir.path()),
NULL,
NULL,
NULL,
true,
-1);
CrashWithCallbacks(NULL, DoneCallbackRaiseSIGKILL, temp_dir.path());
}
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGKILL));
}
TEST(ExceptionHandlerTest, StackedHandlersNotDeliveredToBottom) {
AutoTempDir temp_dir;
const pid_t child = fork();
if (child == 0) {
ExceptionHandler bottom(MinidumpDescriptor(temp_dir.path()),
NULL,
DoneCallbackRaiseSIGKILL,
NULL,
true,
-1);
CrashWithCallbacks(NULL, NULL, temp_dir.path());
}
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV));
}
TEST(ExceptionHandlerTest, StackedHandlersFilteredToBottom) {
AutoTempDir temp_dir;
const pid_t child = fork();
if (child == 0) {
ExceptionHandler bottom(MinidumpDescriptor(temp_dir.path()),
NULL,
DoneCallbackRaiseSIGKILL,
NULL,
true,
-1);
CrashWithCallbacks(FilterCallbackReturnFalse, NULL, temp_dir.path());
}
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGKILL));
}
TEST(ExceptionHandlerTest, StackedHandlersUnhandledToBottom) {
AutoTempDir temp_dir;
const pid_t child = fork();
if (child == 0) {
ExceptionHandler bottom(MinidumpDescriptor(temp_dir.path()),
NULL,
DoneCallbackRaiseSIGKILL,
NULL,
true,
-1);
CrashWithCallbacks(NULL, DoneCallbackReturnFalse, temp_dir.path());
}
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGKILL));
}
namespace {
const int kSimpleFirstChanceReturnStatus = 42;
bool SimpleFirstChanceHandler(int, siginfo_t*, void*) {
_exit(kSimpleFirstChanceReturnStatus);
}
}
TEST(ExceptionHandlerTest, FirstChanceHandlerRuns) {
AutoTempDir temp_dir;
const pid_t child = fork();
if (child == 0) {
ExceptionHandler handler(
MinidumpDescriptor(temp_dir.path()), NULL, NULL, NULL, true, -1);
google_breakpad::SetFirstChanceExceptionHandler(SimpleFirstChanceHandler);
DoNullPointerDereference();
}
int status;
ASSERT_NE(HANDLE_EINTR(waitpid(child, &status, 0)), -1);
ASSERT_TRUE(WIFEXITED(status));
ASSERT_EQ(kSimpleFirstChanceReturnStatus, WEXITSTATUS(status));
}
#endif // !ADDRESS_SANITIZER
const unsigned char kIllegalInstruction[] = {
#if defined(__mips__)
// mfc2 zero,Impl - usually illegal in userspace.
0x48, 0x00, 0x00, 0x48
#else
// This crashes with SIGILL on x86/x86-64/arm.
0xff, 0xff, 0xff, 0xff
#endif
};
// Test that memory around the instruction pointer is written
// to the dump as a MinidumpMemoryRegion.
TEST(ExceptionHandlerTest, InstructionPointerMemory) {
AutoTempDir temp_dir;
int fds[2];
ASSERT_NE(pipe(fds), -1);
// These are defined here so the parent can use them to check the
// data from the minidump afterwards.
const uint32_t kMemorySize = 256; // bytes
const int kOffset = kMemorySize / 2;
const pid_t child = fork();
if (child == 0) {
close(fds[0]);
ExceptionHandler handler(MinidumpDescriptor(temp_dir.path()), NULL,
DoneCallback, reinterpret_cast<void*>(fds[1]),
true, -1);
// Get some executable memory.
char* memory =
reinterpret_cast<char*>(mmap(NULL,
kMemorySize,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE | MAP_ANON,
-1,
0));
if (!memory)
exit(0);
// Write some instructions that will crash. Put them in the middle
// of the block of memory, because the minidump should contain 128
// bytes on either side of the instruction pointer.
memcpy(memory + kOffset, kIllegalInstruction, sizeof(kIllegalInstruction));
FlushInstructionCache(memory, kMemorySize);
// Now execute the instructions, which should crash.
typedef void (*void_function)(void);
void_function memory_function =
reinterpret_cast<void_function>(memory + kOffset);
memory_function();
}
close(fds[1]);
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGILL));
string minidump_path;
ASSERT_NO_FATAL_FAILURE(ReadMinidumpPathFromPipe(fds[0], &minidump_path));
struct stat st;
ASSERT_EQ(0, stat(minidump_path.c_str(), &st));
ASSERT_GT(st.st_size, 0);
// Read the minidump. Locate the exception record and the
// memory list, and then ensure that there is a memory region
// in the memory list that covers the instruction pointer from
// the exception record.
Minidump minidump(minidump_path);
ASSERT_TRUE(minidump.Read());
MinidumpException* exception = minidump.GetException();
MinidumpMemoryList* memory_list = minidump.GetMemoryList();
ASSERT_TRUE(exception);
ASSERT_TRUE(memory_list);
ASSERT_LT(0U, memory_list->region_count());
MinidumpContext* context = exception->GetContext();
ASSERT_TRUE(context);
uint64_t instruction_pointer;
ASSERT_TRUE(context->GetInstructionPointer(&instruction_pointer));
MinidumpMemoryRegion* region =
memory_list->GetMemoryRegionForAddress(instruction_pointer);
ASSERT_TRUE(region);
EXPECT_EQ(kMemorySize, region->GetSize());
const uint8_t* bytes = region->GetMemory();
ASSERT_TRUE(bytes);
uint8_t prefix_bytes[kOffset];
uint8_t suffix_bytes[kMemorySize - kOffset - sizeof(kIllegalInstruction)];
memset(prefix_bytes, 0, sizeof(prefix_bytes));
memset(suffix_bytes, 0, sizeof(suffix_bytes));
EXPECT_TRUE(memcmp(bytes, prefix_bytes, sizeof(prefix_bytes)) == 0);
EXPECT_TRUE(memcmp(bytes + kOffset, kIllegalInstruction,
sizeof(kIllegalInstruction)) == 0);
EXPECT_TRUE(memcmp(bytes + kOffset + sizeof(kIllegalInstruction),
suffix_bytes, sizeof(suffix_bytes)) == 0);
unlink(minidump_path.c_str());
}
// Test that the memory region around the instruction pointer is
// bounded correctly on the low end.
TEST(ExceptionHandlerTest, InstructionPointerMemoryMinBound) {
AutoTempDir temp_dir;
int fds[2];
ASSERT_NE(pipe(fds), -1);
// These are defined here so the parent can use them to check the
// data from the minidump afterwards.
const uint32_t kMemorySize = 256; // bytes
const int kOffset = 0;
const pid_t child = fork();
if (child == 0) {
close(fds[0]);
ExceptionHandler handler(MinidumpDescriptor(temp_dir.path()), NULL,
DoneCallback, reinterpret_cast<void*>(fds[1]),
true, -1);
// Get some executable memory.
char* memory =
reinterpret_cast<char*>(mmap(NULL,
kMemorySize,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE | MAP_ANON,
-1,
0));
if (!memory)
exit(0);
// Write some instructions that will crash. Put them in the middle
// of the block of memory, because the minidump should contain 128
// bytes on either side of the instruction pointer.
memcpy(memory + kOffset, kIllegalInstruction, sizeof(kIllegalInstruction));
FlushInstructionCache(memory, kMemorySize);
// Now execute the instructions, which should crash.
typedef void (*void_function)(void);
void_function memory_function =
reinterpret_cast<void_function>(memory + kOffset);
memory_function();
}
close(fds[1]);
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGILL));
string minidump_path;
ASSERT_NO_FATAL_FAILURE(ReadMinidumpPathFromPipe(fds[0], &minidump_path));
struct stat st;
ASSERT_EQ(0, stat(minidump_path.c_str(), &st));
ASSERT_GT(st.st_size, 0);
// Read the minidump. Locate the exception record and the
// memory list, and then ensure that there is a memory region
// in the memory list that covers the instruction pointer from
// the exception record.
Minidump minidump(minidump_path);
ASSERT_TRUE(minidump.Read());
MinidumpException* exception = minidump.GetException();
MinidumpMemoryList* memory_list = minidump.GetMemoryList();
ASSERT_TRUE(exception);
ASSERT_TRUE(memory_list);
ASSERT_LT(0U, memory_list->region_count());
MinidumpContext* context = exception->GetContext();
ASSERT_TRUE(context);
uint64_t instruction_pointer;
ASSERT_TRUE(context->GetInstructionPointer(&instruction_pointer));
MinidumpMemoryRegion* region =
memory_list->GetMemoryRegionForAddress(instruction_pointer);
ASSERT_TRUE(region);
EXPECT_EQ(kMemorySize / 2, region->GetSize());
const uint8_t* bytes = region->GetMemory();
ASSERT_TRUE(bytes);
uint8_t suffix_bytes[kMemorySize / 2 - sizeof(kIllegalInstruction)];
memset(suffix_bytes, 0, sizeof(suffix_bytes));
EXPECT_TRUE(memcmp(bytes + kOffset, kIllegalInstruction,
sizeof(kIllegalInstruction)) == 0);
EXPECT_TRUE(memcmp(bytes + kOffset + sizeof(kIllegalInstruction),
suffix_bytes, sizeof(suffix_bytes)) == 0);
unlink(minidump_path.c_str());
}
// Test that the memory region around the instruction pointer is
// bounded correctly on the high end.
TEST(ExceptionHandlerTest, InstructionPointerMemoryMaxBound) {
AutoTempDir temp_dir;
int fds[2];
ASSERT_NE(pipe(fds), -1);
// These are defined here so the parent can use them to check the
// data from the minidump afterwards.
// Use 4k here because the OS will hand out a single page even
// if a smaller size is requested, and this test wants to
// test the upper bound of the memory range.
const uint32_t kMemorySize = 4096; // bytes
const int kOffset = kMemorySize - sizeof(kIllegalInstruction);
const pid_t child = fork();
if (child == 0) {
close(fds[0]);
ExceptionHandler handler(MinidumpDescriptor(temp_dir.path()), NULL,
DoneCallback, reinterpret_cast<void*>(fds[1]),
true, -1);
// Get some executable memory.
char* memory =
reinterpret_cast<char*>(mmap(NULL,
kMemorySize,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE | MAP_ANON,
-1,
0));
if (!memory)
exit(0);
// Write some instructions that will crash. Put them in the middle
// of the block of memory, because the minidump should contain 128
// bytes on either side of the instruction pointer.
memcpy(memory + kOffset, kIllegalInstruction, sizeof(kIllegalInstruction));
FlushInstructionCache(memory, kMemorySize);
// Now execute the instructions, which should crash.
typedef void (*void_function)(void);
void_function memory_function =
reinterpret_cast<void_function>(memory + kOffset);
memory_function();
}
close(fds[1]);
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGILL));
string minidump_path;
ASSERT_NO_FATAL_FAILURE(ReadMinidumpPathFromPipe(fds[0], &minidump_path));
struct stat st;
ASSERT_EQ(0, stat(minidump_path.c_str(), &st));
ASSERT_GT(st.st_size, 0);
// Read the minidump. Locate the exception record and the memory list, and
// then ensure that there is a memory region in the memory list that covers
// the instruction pointer from the exception record.
Minidump minidump(minidump_path);
ASSERT_TRUE(minidump.Read());
MinidumpException* exception = minidump.GetException();
MinidumpMemoryList* memory_list = minidump.GetMemoryList();
ASSERT_TRUE(exception);
ASSERT_TRUE(memory_list);
ASSERT_LT(0U, memory_list->region_count());
MinidumpContext* context = exception->GetContext();
ASSERT_TRUE(context);
uint64_t instruction_pointer;
ASSERT_TRUE(context->GetInstructionPointer(&instruction_pointer));
MinidumpMemoryRegion* region =
memory_list->GetMemoryRegionForAddress(instruction_pointer);
ASSERT_TRUE(region);
const size_t kPrefixSize = 128; // bytes
EXPECT_EQ(kPrefixSize + sizeof(kIllegalInstruction), region->GetSize());
const uint8_t* bytes = region->GetMemory();
ASSERT_TRUE(bytes);
uint8_t prefix_bytes[kPrefixSize];
memset(prefix_bytes, 0, sizeof(prefix_bytes));
EXPECT_TRUE(memcmp(bytes, prefix_bytes, sizeof(prefix_bytes)) == 0);
EXPECT_TRUE(memcmp(bytes + kPrefixSize,
kIllegalInstruction, sizeof(kIllegalInstruction)) == 0);
unlink(minidump_path.c_str());
}
#ifndef ADDRESS_SANITIZER
// Ensure that an extra memory block doesn't get added when the instruction
// pointer is not in mapped memory.
TEST(ExceptionHandlerTest, InstructionPointerMemoryNullPointer) {
AutoTempDir temp_dir;
int fds[2];
ASSERT_NE(pipe(fds), -1);
const pid_t child = fork();
if (child == 0) {
close(fds[0]);
ExceptionHandler handler(MinidumpDescriptor(temp_dir.path()), NULL,
DoneCallback, reinterpret_cast<void*>(fds[1]),
true, -1);
// Try calling a NULL pointer.
typedef void (*void_function)(void);
// Volatile markings are needed to keep Clang from generating invalid
volatile void_function memory_function =
reinterpret_cast<void_function>(NULL);
memory_function();
// not reached
exit(1);
}
close(fds[1]);
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV));
string minidump_path;
ASSERT_NO_FATAL_FAILURE(ReadMinidumpPathFromPipe(fds[0], &minidump_path));
struct stat st;
ASSERT_EQ(0, stat(minidump_path.c_str(), &st));
ASSERT_GT(st.st_size, 0);
// Read the minidump. Locate the exception record and the
// memory list, and then ensure that there is no memory region
// in the memory list that covers the instruction pointer from
// the exception record.
Minidump minidump(minidump_path);
ASSERT_TRUE(minidump.Read());
MinidumpException* exception = minidump.GetException();
ASSERT_TRUE(exception);
MinidumpContext* exception_context = exception->GetContext();
ASSERT_TRUE(exception_context);
uint64_t instruction_pointer;
ASSERT_TRUE(exception_context->GetInstructionPointer(&instruction_pointer));
EXPECT_EQ(instruction_pointer, 0u);
MinidumpMemoryList* memory_list = minidump.GetMemoryList();
ASSERT_TRUE(memory_list);
unsigned int region_count = memory_list->region_count();
ASSERT_GE(region_count, 1u);
for (unsigned int region_index = 0;
region_index < region_count;
++region_index) {
MinidumpMemoryRegion* region =
memory_list->GetMemoryRegionAtIndex(region_index);
uint64_t region_base = region->GetBase();
EXPECT_FALSE(instruction_pointer >= region_base &&
instruction_pointer < region_base + region->GetSize());
}
unlink(minidump_path.c_str());
}
#endif // !ADDRESS_SANITIZER
// Test that anonymous memory maps can be annotated with names and IDs.
TEST(ExceptionHandlerTest, ModuleInfo) {
// 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);
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,
kMemorySize,
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON,
-1,
0));
const uintptr_t kMemoryAddress = reinterpret_cast<uintptr_t>(memory);
ASSERT_TRUE(memory);
PageAllocator allocator;
auto_wasteful_vector<uint8_t, sizeof(MDGUID)> guid(&allocator);
guid.assign(std::begin(kModuleGUID), std::end(kModuleGUID));
AutoTempDir temp_dir;
ExceptionHandler handler(
MinidumpDescriptor(temp_dir.path()), NULL, NULL, NULL, true, -1);
// Add info about the anonymous memory mapping.
handler.AddMappingInfo(kMemoryName,
guid,
kMemoryAddress,
kMemorySize,
0);
ASSERT_TRUE(handler.WriteMinidump());
const MinidumpDescriptor& minidump_desc = handler.minidump_descriptor();
// 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(minidump_desc.path());
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(kMemorySize, module->size());
EXPECT_EQ(kMemoryName, module->code_file());
EXPECT_EQ(module_identifier, module->debug_identifier());
unlink(minidump_desc.path());
}
#ifndef ADDRESS_SANITIZER
static const unsigned kControlMsgSize =
CMSG_SPACE(sizeof(int)) + CMSG_SPACE(sizeof(struct ucred));
static bool
CrashHandler(const void* crash_context, size_t crash_context_size,
void* context) {
const int fd = (intptr_t) context;
int fds[2];
if (pipe(fds) == -1) {
// There doesn't seem to be any way to reliably handle
// this failure without the parent process hanging
// At least make sure that this process doesn't access
// unexpected file descriptors
fds[0] = -1;
fds[1] = -1;
}
struct kernel_msghdr msg = {0};
struct kernel_iovec iov;
iov.iov_base = const_cast<void*>(crash_context);
iov.iov_len = crash_context_size;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
char cmsg[kControlMsgSize];
memset(cmsg, 0, kControlMsgSize);
msg.msg_control = cmsg;
msg.msg_controllen = sizeof(cmsg);
struct cmsghdr *hdr = CMSG_FIRSTHDR(&msg);
hdr->cmsg_level = SOL_SOCKET;
hdr->cmsg_type = SCM_RIGHTS;
hdr->cmsg_len = CMSG_LEN(sizeof(int));
*((int*) CMSG_DATA(hdr)) = fds[1];
hdr = CMSG_NXTHDR((struct msghdr*) &msg, hdr);
hdr->cmsg_level = SOL_SOCKET;
hdr->cmsg_type = SCM_CREDENTIALS;
hdr->cmsg_len = CMSG_LEN(sizeof(struct ucred));
struct ucred *cred = reinterpret_cast<struct ucred*>(CMSG_DATA(hdr));
cred->uid = getuid();
cred->gid = getgid();
cred->pid = getpid();
ssize_t ret = HANDLE_EINTR(sys_sendmsg(fd, &msg, 0));
sys_close(fds[1]);
if (ret <= 0)
return false;
char b;
IGNORE_RET(HANDLE_EINTR(sys_read(fds[0], &b, 1)));
return true;
}
TEST(ExceptionHandlerTest, ExternalDumper) {
int fds[2];
ASSERT_NE(socketpair(AF_UNIX, SOCK_DGRAM, 0, fds), -1);
static const int on = 1;
setsockopt(fds[0], SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
setsockopt(fds[1], SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
const pid_t child = fork();
if (child == 0) {
close(fds[0]);
ExceptionHandler handler(MinidumpDescriptor("/tmp1"), NULL, NULL,
reinterpret_cast<void*>(fds[1]), true, -1);
handler.set_crash_handler(CrashHandler);
DoNullPointerDereference();
}
close(fds[1]);
struct msghdr msg = {0};
struct iovec iov;
static const unsigned kCrashContextSize =
sizeof(ExceptionHandler::CrashContext);
char context[kCrashContextSize];
char control[kControlMsgSize];
iov.iov_base = context;
iov.iov_len = kCrashContextSize;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = control;
msg.msg_controllen = kControlMsgSize;
const ssize_t n = HANDLE_EINTR(recvmsg(fds[0], &msg, 0));
ASSERT_EQ(static_cast<ssize_t>(kCrashContextSize), n);
ASSERT_EQ(kControlMsgSize, msg.msg_controllen);
ASSERT_EQ(static_cast<__typeof__(msg.msg_flags)>(0), msg.msg_flags);
ASSERT_EQ(0, close(fds[0]));
pid_t crashing_pid = -1;
int signal_fd = -1;
for (struct cmsghdr *hdr = CMSG_FIRSTHDR(&msg); hdr;
hdr = CMSG_NXTHDR(&msg, hdr)) {
if (hdr->cmsg_level != SOL_SOCKET)
continue;
if (hdr->cmsg_type == SCM_RIGHTS) {
const unsigned len = hdr->cmsg_len -
(((uint8_t*)CMSG_DATA(hdr)) - (uint8_t*)hdr);
ASSERT_EQ(sizeof(int), len);
signal_fd = *(reinterpret_cast<int*>(CMSG_DATA(hdr)));
} else if (hdr->cmsg_type == SCM_CREDENTIALS) {
const struct ucred *cred =
reinterpret_cast<struct ucred*>(CMSG_DATA(hdr));
crashing_pid = cred->pid;
}
}
ASSERT_NE(crashing_pid, -1);
ASSERT_NE(signal_fd, -1);
AutoTempDir temp_dir;
string templ = temp_dir.path() + "/exception-handler-unittest";
ASSERT_TRUE(WriteMinidump(templ.c_str(), crashing_pid, context,
kCrashContextSize));
static const char b = 0;
ASSERT_EQ(1, (HANDLE_EINTR(write(signal_fd, &b, 1))));
ASSERT_EQ(0, close(signal_fd));
ASSERT_NO_FATAL_FAILURE(WaitForProcessToTerminate(child, SIGSEGV));
struct stat st;
ASSERT_EQ(0, stat(templ.c_str(), &st));
ASSERT_GT(st.st_size, 0);
unlink(templ.c_str());
}
#endif // !ADDRESS_SANITIZER
TEST(ExceptionHandlerTest, WriteMinidumpExceptionStream) {
AutoTempDir temp_dir;
ExceptionHandler handler(MinidumpDescriptor(temp_dir.path()), NULL, NULL,
NULL, false, -1);
ASSERT_TRUE(handler.WriteMinidump());
string minidump_path = handler.minidump_descriptor().path();
// Read the minidump and check the exception stream.
Minidump minidump(minidump_path);
ASSERT_TRUE(minidump.Read());
MinidumpException* exception = minidump.GetException();
ASSERT_TRUE(exception);
const MDRawExceptionStream* raw = exception->exception();
ASSERT_TRUE(raw);
EXPECT_EQ(MD_EXCEPTION_CODE_LIN_DUMP_REQUESTED,
raw->exception_record.exception_code);
}
TEST(ExceptionHandlerTest, GenerateMultipleDumpsWithFD) {
AutoTempDir temp_dir;
string path;
const int fd = CreateTMPFile(temp_dir.path(), &path);
ExceptionHandler handler(MinidumpDescriptor(fd), NULL, NULL, NULL, false, -1);
ASSERT_TRUE(handler.WriteMinidump());
// Check by the size of the data written to the FD that a minidump was
// generated.
off_t size = lseek(fd, 0, SEEK_CUR);
ASSERT_GT(size, 0);
// Generate another minidump.
ASSERT_TRUE(handler.WriteMinidump());
size = lseek(fd, 0, SEEK_CUR);
ASSERT_GT(size, 0);
}
TEST(ExceptionHandlerTest, GenerateMultipleDumpsWithPath) {
AutoTempDir temp_dir;
ExceptionHandler handler(MinidumpDescriptor(temp_dir.path()), NULL, NULL,
NULL, false, -1);
ASSERT_TRUE(handler.WriteMinidump());
const MinidumpDescriptor& minidump_1 = handler.minidump_descriptor();
struct stat st;
ASSERT_EQ(0, stat(minidump_1.path(), &st));
ASSERT_GT(st.st_size, 0);
string minidump_1_path(minidump_1.path());
// Check it is a valid minidump.
Minidump minidump1(minidump_1_path);
ASSERT_TRUE(minidump1.Read());
unlink(minidump_1.path());
// Generate another minidump, it should go to a different file.
ASSERT_TRUE(handler.WriteMinidump());
const MinidumpDescriptor& minidump_2 = handler.minidump_descriptor();
ASSERT_EQ(0, stat(minidump_2.path(), &st));
ASSERT_GT(st.st_size, 0);
string minidump_2_path(minidump_2.path());
// Check it is a valid minidump.
Minidump minidump2(minidump_2_path);
ASSERT_TRUE(minidump2.Read());
unlink(minidump_2.path());
// 2 distinct files should be produced.
ASSERT_STRNE(minidump_1_path.c_str(), minidump_2_path.c_str());
}
// Test that an additional memory region can be added to the minidump.
TEST(ExceptionHandlerTest, AdditionalMemory) {
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;
}
AutoTempDir temp_dir;
ExceptionHandler handler(
MinidumpDescriptor(temp_dir.path()), NULL, NULL, NULL, true, -1);
// Add the memory region to the list of memory to be included.
handler.RegisterAppMemory(memory, kMemorySize);
handler.WriteMinidump();
const MinidumpDescriptor& minidump_desc = handler.minidump_descriptor();
// Read the minidump. Ensure that the memory region is present
Minidump minidump(minidump_desc.path());
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;
}
// Test that a memory region that was previously registered
// can be unregistered.
TEST(ExceptionHandlerTest, AdditionalMemoryRemove) {
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);
AutoTempDir temp_dir;
ExceptionHandler handler(
MinidumpDescriptor(temp_dir.path()), NULL, NULL, NULL, true, -1);
// Add the memory region to the list of memory to be included.
handler.RegisterAppMemory(memory, kMemorySize);
// ...and then remove it
handler.UnregisterAppMemory(memory);
handler.WriteMinidump();
const MinidumpDescriptor& minidump_desc = handler.minidump_descriptor();
// Read the minidump. Ensure that the memory region is not present.
Minidump minidump(minidump_desc.path());
ASSERT_TRUE(minidump.Read());
MinidumpMemoryList* dump_memory_list = minidump.GetMemoryList();
ASSERT_TRUE(dump_memory_list);
const MinidumpMemoryRegion* region =
dump_memory_list->GetMemoryRegionForAddress(kMemoryAddress);
EXPECT_FALSE(region);
delete[] memory;
}
static bool SimpleCallback(const MinidumpDescriptor& descriptor,
void* context,
bool succeeded) {
string* filename = reinterpret_cast<string*>(context);
*filename = descriptor.path();
return true;
}
TEST(ExceptionHandlerTest, WriteMinidumpForChild) {
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);
}
close(fds[0]);
AutoTempDir temp_dir;
string minidump_filename;
ASSERT_TRUE(
ExceptionHandler::WriteMinidumpForChild(child, child,
temp_dir.path(), SimpleCallback,
(void*)&minidump_filename));
Minidump minidump(minidump_filename);
ASSERT_TRUE(minidump.Read());
// Check that the crashing thread is the main thread of |child|
MinidumpException* exception = minidump.GetException();
ASSERT_TRUE(exception);
uint32_t thread_id;
ASSERT_TRUE(exception->GetThreadID(&thread_id));
EXPECT_EQ(child, static_cast<int32_t>(thread_id));
const MDRawExceptionStream* raw = exception->exception();
ASSERT_TRUE(raw);
EXPECT_EQ(MD_EXCEPTION_CODE_LIN_DUMP_REQUESTED,
raw->exception_record.exception_code);
close(fds[1]);
unlink(minidump_filename.c_str());
}