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platform_system_core/debuggerd/debuggerd_test.cpp
Christopher Ferris a3e9a0b2e1 Always use main thread pid for manual dumping. 
When running debuggerd from the command line, it's possible that
the signal will happen on a side thread. The original intercept
in tombstoned is set to only handle crashes from the main thread
pid, so in this case, the intercept doesn't occur. To fix this,
modify the code so that running debuggerd always sends the signal
to the main pid. In addition, modify the signal handler is entered
due to the BIONIC_SIGNAL_DEBUGGER signal, then the crashing tid is
set to the main thread pid instead of the current thread.

Add unit test to cover this case.

Bug: 194346289

Test: All unit tests pass.
Test: Verify the new unit test is getting the signal on the non-main
Test: thread and still properly handling the intercept.
Test: Modify the debuggerd code to send the signal to the non main pid
Test: and verify the dump still occurs correctly.

Change-Id: I2dd1bd11fc8ef4a6fe87f05ecc67ae349a101c82
2021-07-30 14:08:03 -07:00

1853 lines
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/*
* Copyright 2016, The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <dirent.h>
#include <dlfcn.h>
#include <err.h>
#include <fcntl.h>
#include <malloc.h>
#include <stdlib.h>
#include <sys/capability.h>
#include <sys/mman.h>
#include <sys/prctl.h>
#include <sys/ptrace.h>
#include <sys/resource.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
#include <chrono>
#include <regex>
#include <string>
#include <thread>
#include <android/fdsan.h>
#include <android/set_abort_message.h>
#include <bionic/malloc.h>
#include <bionic/mte.h>
#include <bionic/reserved_signals.h>
#include <android-base/cmsg.h>
#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/macros.h>
#include <android-base/parseint.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <android-base/test_utils.h>
#include <android-base/unique_fd.h>
#include <cutils/sockets.h>
#include <gmock/gmock.h>
#include <gtest/gtest.h>
#include <libminijail.h>
#include <scoped_minijail.h>
#include "debuggerd/handler.h"
#include "libdebuggerd/utility.h"
#include "protocol.h"
#include "tombstoned/tombstoned.h"
#include "util.h"
using namespace std::chrono_literals;
using android::base::SendFileDescriptors;
using android::base::unique_fd;
using ::testing::HasSubstr;
#if defined(__LP64__)
#define ARCH_SUFFIX "64"
#else
#define ARCH_SUFFIX ""
#endif
constexpr char kWaitForDebuggerKey[] = "debug.debuggerd.wait_for_debugger";
#define TIMEOUT(seconds, expr) \
[&]() { \
struct sigaction old_sigaction; \
struct sigaction new_sigaction = {}; \
new_sigaction.sa_handler = [](int) {}; \
if (sigaction(SIGALRM, &new_sigaction, &new_sigaction) != 0) { \
err(1, "sigaction failed"); \
} \
alarm(seconds); \
auto value = expr; \
int saved_errno = errno; \
if (sigaction(SIGALRM, &old_sigaction, nullptr) != 0) { \
err(1, "sigaction failed"); \
} \
alarm(0); \
errno = saved_errno; \
return value; \
}()
// Backtrace frame dump could contain:
// #01 pc 0001cded /data/tmp/debuggerd_test32 (raise_debugger_signal+80)
// or
// #01 pc 00022a09 /data/tmp/debuggerd_test32 (offset 0x12000) (raise_debugger_signal+80)
#define ASSERT_BACKTRACE_FRAME(result, frame_name) \
ASSERT_MATCH(result, \
R"(#\d\d pc [0-9a-f]+\s+ \S+ (\(offset 0x[0-9a-f]+\) )?\()" frame_name R"(\+)");
// Enable GWP-ASan at the start of this process. GWP-ASan is enabled using
// process sampling, so we need to ensure we force GWP-ASan on.
__attribute__((constructor)) static void enable_gwp_asan() {
bool force = true;
android_mallopt(M_INITIALIZE_GWP_ASAN, &force, sizeof(force));
}
static void tombstoned_intercept(pid_t target_pid, unique_fd* intercept_fd, unique_fd* output_fd,
InterceptStatus* status, DebuggerdDumpType intercept_type) {
intercept_fd->reset(socket_local_client(kTombstonedInterceptSocketName,
ANDROID_SOCKET_NAMESPACE_RESERVED, SOCK_SEQPACKET));
if (intercept_fd->get() == -1) {
FAIL() << "failed to contact tombstoned: " << strerror(errno);
}
InterceptRequest req = {
.dump_type = intercept_type,
.pid = target_pid,
};
unique_fd output_pipe_write;
if (!Pipe(output_fd, &output_pipe_write)) {
FAIL() << "failed to create output pipe: " << strerror(errno);
}
std::string pipe_size_str;
int pipe_buffer_size;
if (!android::base::ReadFileToString("/proc/sys/fs/pipe-max-size", &pipe_size_str)) {
FAIL() << "failed to read /proc/sys/fs/pipe-max-size: " << strerror(errno);
}
pipe_size_str = android::base::Trim(pipe_size_str);
if (!android::base::ParseInt(pipe_size_str.c_str(), &pipe_buffer_size, 0)) {
FAIL() << "failed to parse pipe max size";
}
if (fcntl(output_fd->get(), F_SETPIPE_SZ, pipe_buffer_size) != pipe_buffer_size) {
FAIL() << "failed to set pipe size: " << strerror(errno);
}
ASSERT_GE(pipe_buffer_size, 1024 * 1024);
ssize_t rc = SendFileDescriptors(intercept_fd->get(), &req, sizeof(req), output_pipe_write.get());
output_pipe_write.reset();
if (rc != sizeof(req)) {
FAIL() << "failed to send output fd to tombstoned: " << strerror(errno);
}
InterceptResponse response;
rc = TEMP_FAILURE_RETRY(read(intercept_fd->get(), &response, sizeof(response)));
if (rc == -1) {
FAIL() << "failed to read response from tombstoned: " << strerror(errno);
} else if (rc == 0) {
FAIL() << "failed to read response from tombstoned (EOF)";
} else if (rc != sizeof(response)) {
FAIL() << "received packet of unexpected length from tombstoned: expected " << sizeof(response)
<< ", received " << rc;
}
*status = response.status;
}
class CrasherTest : public ::testing::Test {
public:
pid_t crasher_pid = -1;
bool previous_wait_for_debugger;
unique_fd crasher_pipe;
unique_fd intercept_fd;
CrasherTest();
~CrasherTest();
void StartIntercept(unique_fd* output_fd, DebuggerdDumpType intercept_type = kDebuggerdTombstone);
// Returns -1 if we fail to read a response from tombstoned, otherwise the received return code.
void FinishIntercept(int* result);
void StartProcess(std::function<void()> function, std::function<pid_t()> forker = fork);
void StartCrasher(const std::string& crash_type);
void FinishCrasher();
void AssertDeath(int signo);
static void Trap(void* ptr);
};
CrasherTest::CrasherTest() {
previous_wait_for_debugger = android::base::GetBoolProperty(kWaitForDebuggerKey, false);
android::base::SetProperty(kWaitForDebuggerKey, "0");
// Clear the old property too, just in case someone's been using it
// on this device. (We only document the new name, but we still support
// the old name so we don't break anyone's existing setups.)
android::base::SetProperty("debug.debuggerd.wait_for_gdb", "0");
}
CrasherTest::~CrasherTest() {
if (crasher_pid != -1) {
kill(crasher_pid, SIGKILL);
int status;
TEMP_FAILURE_RETRY(waitpid(crasher_pid, &status, WUNTRACED));
}
android::base::SetProperty(kWaitForDebuggerKey, previous_wait_for_debugger ? "1" : "0");
}
void CrasherTest::StartIntercept(unique_fd* output_fd, DebuggerdDumpType intercept_type) {
if (crasher_pid == -1) {
FAIL() << "crasher hasn't been started";
}
InterceptStatus status;
tombstoned_intercept(crasher_pid, &this->intercept_fd, output_fd, &status, intercept_type);
ASSERT_EQ(InterceptStatus::kRegistered, status);
}
void CrasherTest::FinishIntercept(int* result) {
InterceptResponse response;
ssize_t rc = TIMEOUT(30, read(intercept_fd.get(), &response, sizeof(response)));
if (rc == -1) {
FAIL() << "failed to read response from tombstoned: " << strerror(errno);
} else if (rc == 0) {
*result = -1;
} else if (rc != sizeof(response)) {
FAIL() << "received packet of unexpected length from tombstoned: expected " << sizeof(response)
<< ", received " << rc;
} else {
*result = response.status == InterceptStatus::kStarted ? 1 : 0;
}
}
void CrasherTest::StartProcess(std::function<void()> function, std::function<pid_t()> forker) {
unique_fd read_pipe;
unique_fd crasher_read_pipe;
if (!Pipe(&crasher_read_pipe, &crasher_pipe)) {
FAIL() << "failed to create pipe: " << strerror(errno);
}
crasher_pid = forker();
if (crasher_pid == -1) {
FAIL() << "fork failed: " << strerror(errno);
} else if (crasher_pid == 0) {
char dummy;
crasher_pipe.reset();
TEMP_FAILURE_RETRY(read(crasher_read_pipe.get(), &dummy, 1));
function();
_exit(0);
}
}
void CrasherTest::FinishCrasher() {
if (crasher_pipe == -1) {
FAIL() << "crasher pipe uninitialized";
}
ssize_t rc = TEMP_FAILURE_RETRY(write(crasher_pipe.get(), "\n", 1));
if (rc == -1) {
FAIL() << "failed to write to crasher pipe: " << strerror(errno);
} else if (rc == 0) {
FAIL() << "crasher pipe was closed";
}
}
void CrasherTest::AssertDeath(int signo) {
int status;
pid_t pid = TIMEOUT(30, waitpid(crasher_pid, &status, 0));
if (pid != crasher_pid) {
printf("failed to wait for crasher (expected pid %d, return value %d): %s\n", crasher_pid, pid,
strerror(errno));
sleep(100);
FAIL() << "failed to wait for crasher: " << strerror(errno);
}
if (signo == 0) {
ASSERT_TRUE(WIFEXITED(status)) << "Terminated due to unexpected signal " << WTERMSIG(status);
ASSERT_EQ(0, WEXITSTATUS(signo));
} else {
ASSERT_FALSE(WIFEXITED(status));
ASSERT_TRUE(WIFSIGNALED(status)) << "crasher didn't terminate via a signal";
ASSERT_EQ(signo, WTERMSIG(status));
}
crasher_pid = -1;
}
static void ConsumeFd(unique_fd fd, std::string* output) {
constexpr size_t read_length = PAGE_SIZE;
std::string result;
while (true) {
size_t offset = result.size();
result.resize(result.size() + PAGE_SIZE);
ssize_t rc = TEMP_FAILURE_RETRY(read(fd.get(), &result[offset], read_length));
if (rc == -1) {
FAIL() << "read failed: " << strerror(errno);
} else if (rc == 0) {
result.resize(result.size() - PAGE_SIZE);
break;
}
result.resize(result.size() - PAGE_SIZE + rc);
}
*output = std::move(result);
}
class LogcatCollector {
public:
LogcatCollector() { system("logcat -c"); }
void Collect(std::string* output) {
FILE* cmd_stdout = popen("logcat -d '*:S DEBUG'", "r");
ASSERT_NE(cmd_stdout, nullptr);
unique_fd tmp_fd(TEMP_FAILURE_RETRY(dup(fileno(cmd_stdout))));
ConsumeFd(std::move(tmp_fd), output);
pclose(cmd_stdout);
}
};
TEST_F(CrasherTest, smoke) {
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
*reinterpret_cast<volatile char*>(0xdead) = '1';
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(result, R"(signal 11 \(SIGSEGV\), code 1 \(SEGV_MAPERR\), fault addr 0xdead)");
if (mte_supported()) {
// Test that the default TAGGED_ADDR_CTRL value is set.
ASSERT_MATCH(result, R"(tagged_addr_ctrl: 000000000007fff3)");
}
}
TEST_F(CrasherTest, tagged_fault_addr) {
#if !defined(__aarch64__)
GTEST_SKIP() << "Requires aarch64";
#endif
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
*reinterpret_cast<volatile char*>(0x100000000000dead) = '1';
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
// The address can either be tagged (new kernels) or untagged (old kernels).
ASSERT_MATCH(
result,
R"(signal 11 \(SIGSEGV\), code 1 \(SEGV_MAPERR\), fault addr (0x100000000000dead|0xdead))");
}
// Marked as weak to prevent the compiler from removing the malloc in the caller. In theory, the
// compiler could still clobber the argument register before trapping, but that's unlikely.
__attribute__((weak)) void CrasherTest::Trap(void* ptr ATTRIBUTE_UNUSED) {
__builtin_trap();
}
TEST_F(CrasherTest, heap_addr_in_register) {
#if defined(__i386__)
GTEST_SKIP() << "architecture does not pass arguments in registers";
#endif
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
// Crash with a heap pointer in the first argument register.
Trap(malloc(1));
});
StartIntercept(&output_fd);
FinishCrasher();
int status;
ASSERT_EQ(crasher_pid, TIMEOUT(30, waitpid(crasher_pid, &status, 0)));
ASSERT_TRUE(WIFSIGNALED(status)) << "crasher didn't terminate via a signal";
// Don't test the signal number because different architectures use different signals for
// __builtin_trap().
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
#if defined(__aarch64__)
ASSERT_MATCH(result, "memory near x0 \\(\\[anon:");
#elif defined(__arm__)
ASSERT_MATCH(result, "memory near r0 \\(\\[anon:");
#elif defined(__x86_64__)
ASSERT_MATCH(result, "memory near rdi \\(\\[anon:");
#else
ASSERT_TRUE(false) << "unsupported architecture";
#endif
}
#if defined(__aarch64__)
static void SetTagCheckingLevelSync() {
if (mallopt(M_BIONIC_SET_HEAP_TAGGING_LEVEL, M_HEAP_TAGGING_LEVEL_SYNC) == 0) {
abort();
}
}
#endif
// Number of iterations required to reliably guarantee a GWP-ASan crash.
// GWP-ASan's sample rate is not truly nondeterministic, it initialises a
// thread-local counter at 2*SampleRate, and decrements on each malloc(). Once
// the counter reaches zero, we provide a sampled allocation. Then, double that
// figure to allow for left/right allocation alignment, as this is done randomly
// without bias.
#define GWP_ASAN_ITERATIONS_TO_ENSURE_CRASH (0x20000)
struct GwpAsanTestParameters {
size_t alloc_size;
bool free_before_access;
int access_offset;
std::string cause_needle; // Needle to be found in the "Cause: [GWP-ASan]" line.
};
struct GwpAsanCrasherTest : CrasherTest, testing::WithParamInterface<GwpAsanTestParameters> {};
GwpAsanTestParameters gwp_asan_tests[] = {
{/* alloc_size */ 7, /* free_before_access */ true, /* access_offset */ 0, "Use After Free, 0 bytes into a 7-byte allocation"},
{/* alloc_size */ 7, /* free_before_access */ true, /* access_offset */ 1, "Use After Free, 1 byte into a 7-byte allocation"},
{/* alloc_size */ 7, /* free_before_access */ false, /* access_offset */ 16, "Buffer Overflow, 9 bytes right of a 7-byte allocation"},
{/* alloc_size */ 16, /* free_before_access */ false, /* access_offset */ -1, "Buffer Underflow, 1 byte left of a 16-byte allocation"},
};
INSTANTIATE_TEST_SUITE_P(GwpAsanTests, GwpAsanCrasherTest, testing::ValuesIn(gwp_asan_tests));
TEST_P(GwpAsanCrasherTest, gwp_asan_uaf) {
if (mte_supported()) {
// Skip this test on MTE hardware, as MTE will reliably catch these errors
// instead of GWP-ASan.
GTEST_SKIP() << "Skipped on MTE.";
}
GwpAsanTestParameters params = GetParam();
LogcatCollector logcat_collector;
int intercept_result;
unique_fd output_fd;
StartProcess([&params]() {
for (unsigned i = 0; i < GWP_ASAN_ITERATIONS_TO_ENSURE_CRASH; ++i) {
volatile char* p = reinterpret_cast<volatile char*>(malloc(params.alloc_size));
if (params.free_before_access) free(static_cast<void*>(const_cast<char*>(p)));
p[params.access_offset] = 42;
if (!params.free_before_access) free(static_cast<void*>(const_cast<char*>(p)));
}
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::vector<std::string> log_sources(2);
ConsumeFd(std::move(output_fd), &log_sources[0]);
logcat_collector.Collect(&log_sources[1]);
for (const auto& result : log_sources) {
ASSERT_MATCH(result, R"(signal 11 \(SIGSEGV\), code 2 \(SEGV_ACCERR\))");
ASSERT_MATCH(result, R"(Cause: \[GWP-ASan\]: )" + params.cause_needle);
if (params.free_before_access) {
ASSERT_MATCH(result, R"(deallocated by thread .*\n.*#00 pc)");
}
ASSERT_MATCH(result, R"((^|\s)allocated by thread .*\n.*#00 pc)");
}
}
struct SizeParamCrasherTest : CrasherTest, testing::WithParamInterface<size_t> {};
INSTANTIATE_TEST_SUITE_P(Sizes, SizeParamCrasherTest, testing::Values(0, 16, 131072));
TEST_P(SizeParamCrasherTest, mte_uaf) {
#if defined(__aarch64__)
if (!mte_supported()) {
GTEST_SKIP() << "Requires MTE";
}
// Any UAF on a zero-sized allocation will be out-of-bounds so it won't be reported.
if (GetParam() == 0) {
return;
}
LogcatCollector logcat_collector;
int intercept_result;
unique_fd output_fd;
StartProcess([&]() {
SetTagCheckingLevelSync();
volatile int* p = (volatile int*)malloc(GetParam());
free((void *)p);
p[0] = 42;
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::vector<std::string> log_sources(2);
ConsumeFd(std::move(output_fd), &log_sources[0]);
logcat_collector.Collect(&log_sources[1]);
// Tag dump only available in the tombstone, not logcat.
ASSERT_MATCH(log_sources[0], "Memory tags around the fault address");
for (const auto& result : log_sources) {
ASSERT_MATCH(result, R"(signal 11 \(SIGSEGV\))");
ASSERT_MATCH(result, R"(Cause: \[MTE\]: Use After Free, 0 bytes into a )" +
std::to_string(GetParam()) + R"(-byte allocation)");
ASSERT_MATCH(result, R"(deallocated by thread .*?\n.*#00 pc)");
ASSERT_MATCH(result, R"((^|\s)allocated by thread .*?\n.*#00 pc)");
}
#else
GTEST_SKIP() << "Requires aarch64";
#endif
}
TEST_P(SizeParamCrasherTest, mte_oob_uaf) {
#if defined(__aarch64__)
if (!mte_supported()) {
GTEST_SKIP() << "Requires MTE";
}
int intercept_result;
unique_fd output_fd;
StartProcess([&]() {
SetTagCheckingLevelSync();
volatile int* p = (volatile int*)malloc(GetParam());
free((void *)p);
p[-1] = 42;
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(result, R"(signal 11 \(SIGSEGV\))");
ASSERT_NOT_MATCH(result, R"(Cause: \[MTE\]: Use After Free, 4 bytes left)");
#else
GTEST_SKIP() << "Requires aarch64";
#endif
}
TEST_P(SizeParamCrasherTest, mte_overflow) {
#if defined(__aarch64__)
if (!mte_supported()) {
GTEST_SKIP() << "Requires MTE";
}
LogcatCollector logcat_collector;
int intercept_result;
unique_fd output_fd;
StartProcess([&]() {
SetTagCheckingLevelSync();
volatile char* p = (volatile char*)malloc(GetParam());
p[GetParam()] = 42;
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::vector<std::string> log_sources(2);
ConsumeFd(std::move(output_fd), &log_sources[0]);
logcat_collector.Collect(&log_sources[1]);
// Tag dump only in tombstone, not logcat, and tagging is not used for
// overflow protection in the scudo secondary (guard pages are used instead).
if (GetParam() < 0x10000) {
ASSERT_MATCH(log_sources[0], "Memory tags around the fault address");
}
for (const auto& result : log_sources) {
ASSERT_MATCH(result, R"(signal 11 \(SIGSEGV\))");
ASSERT_MATCH(result, R"(Cause: \[MTE\]: Buffer Overflow, 0 bytes right of a )" +
std::to_string(GetParam()) + R"(-byte allocation)");
ASSERT_MATCH(result, R"((^|\s)allocated by thread .*?\n.*#00 pc)");
}
#else
GTEST_SKIP() << "Requires aarch64";
#endif
}
TEST_P(SizeParamCrasherTest, mte_underflow) {
#if defined(__aarch64__)
if (!mte_supported()) {
GTEST_SKIP() << "Requires MTE";
}
int intercept_result;
unique_fd output_fd;
StartProcess([&]() {
SetTagCheckingLevelSync();
volatile int* p = (volatile int*)malloc(GetParam());
p[-1] = 42;
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(result, R"(signal 11 \(SIGSEGV\), code 9 \(SEGV_MTESERR\))");
ASSERT_MATCH(result, R"(Cause: \[MTE\]: Buffer Underflow, 4 bytes left of a )" +
std::to_string(GetParam()) + R"(-byte allocation)");
ASSERT_MATCH(result, R"((^|\s)allocated by thread .*
#00 pc)");
ASSERT_MATCH(result, "Memory tags around the fault address");
#else
GTEST_SKIP() << "Requires aarch64";
#endif
}
TEST_F(CrasherTest, mte_multiple_causes) {
#if defined(__aarch64__)
if (!mte_supported()) {
GTEST_SKIP() << "Requires MTE";
}
LogcatCollector logcat_collector;
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
SetTagCheckingLevelSync();
// Make two allocations with the same tag and close to one another. Check for both properties
// with a bounds check -- this relies on the fact that only if the allocations have the same tag
// would they be measured as closer than 128 bytes to each other. Otherwise they would be about
// (some non-zero value << 56) apart.
//
// The out-of-bounds access will be considered either an overflow of one or an underflow of the
// other.
std::set<uintptr_t> allocs;
for (int i = 0; i != 4096; ++i) {
uintptr_t alloc = reinterpret_cast<uintptr_t>(malloc(16));
auto it = allocs.insert(alloc).first;
if (it != allocs.begin() && *std::prev(it) + 128 > alloc) {
*reinterpret_cast<int*>(*std::prev(it) + 16) = 42;
}
if (std::next(it) != allocs.end() && alloc + 128 > *std::next(it)) {
*reinterpret_cast<int*>(alloc + 16) = 42;
}
}
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::vector<std::string> log_sources(2);
ConsumeFd(std::move(output_fd), &log_sources[0]);
logcat_collector.Collect(&log_sources[1]);
// Tag dump only in the tombstone, not logcat.
ASSERT_MATCH(log_sources[0], "Memory tags around the fault address");
for (const auto& result : log_sources) {
ASSERT_MATCH(result, R"(signal 11 \(SIGSEGV\))");
ASSERT_THAT(result, HasSubstr("Note: multiple potential causes for this crash were detected, "
"listing them in decreasing order of probability."));
// Adjacent untracked allocations may cause us to see the wrong underflow here (or only
// overflows), so we can't match explicitly for an underflow message.
ASSERT_MATCH(result,
R"(Cause: \[MTE\]: Buffer Overflow, 0 bytes right of a 16-byte allocation)");
// Ensure there's at least two allocation traces (one for each cause).
ASSERT_MATCH(
result,
R"((^|\s)allocated by thread .*?\n.*#00 pc(.|\n)*?(^|\s)allocated by thread .*?\n.*#00 pc)");
}
#else
GTEST_SKIP() << "Requires aarch64";
#endif
}
#if defined(__aarch64__)
static uintptr_t CreateTagMapping() {
// Some of the MTE tag dump tests assert that there is an inaccessible page to the left and right
// of the PROT_MTE page, so map three pages and set the two guard pages to PROT_NONE.
size_t page_size = getpagesize();
void* mapping = mmap(nullptr, page_size * 3, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
uintptr_t mapping_uptr = reinterpret_cast<uintptr_t>(mapping);
if (mapping == MAP_FAILED) {
return 0;
}
mprotect(reinterpret_cast<void*>(mapping_uptr + page_size), page_size,
PROT_READ | PROT_WRITE | PROT_MTE);
// Stripe the mapping, where even granules get tag '1', and odd granules get tag '0'.
for (uintptr_t offset = 0; offset < page_size; offset += 2 * kTagGranuleSize) {
uintptr_t tagged_addr = mapping_uptr + page_size + offset + (1ULL << 56);
__asm__ __volatile__(".arch_extension mte; stg %0, [%0]" : : "r"(tagged_addr) : "memory");
}
return mapping_uptr + page_size;
}
#endif
TEST_F(CrasherTest, mte_register_tag_dump) {
#if defined(__aarch64__)
if (!mte_supported()) {
GTEST_SKIP() << "Requires MTE";
}
int intercept_result;
unique_fd output_fd;
StartProcess([&]() {
SetTagCheckingLevelSync();
Trap(reinterpret_cast<void *>(CreateTagMapping()));
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGTRAP);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(result, R"(memory near x0:
.*
.*
01.............0 0000000000000000 0000000000000000 ................
00.............0)");
#else
GTEST_SKIP() << "Requires aarch64";
#endif
}
TEST_F(CrasherTest, mte_fault_tag_dump_front_truncated) {
#if defined(__aarch64__)
if (!mte_supported()) {
GTEST_SKIP() << "Requires MTE";
}
int intercept_result;
unique_fd output_fd;
StartProcess([&]() {
SetTagCheckingLevelSync();
volatile char* p = reinterpret_cast<char*>(CreateTagMapping());
p[0] = 0; // Untagged pointer, tagged memory.
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(result, R"(Memory tags around the fault address.*
\s*=>0x[0-9a-f]+000:\[1\] 0 1 0)");
#else
GTEST_SKIP() << "Requires aarch64";
#endif
}
TEST_F(CrasherTest, mte_fault_tag_dump) {
#if defined(__aarch64__)
if (!mte_supported()) {
GTEST_SKIP() << "Requires MTE";
}
int intercept_result;
unique_fd output_fd;
StartProcess([&]() {
SetTagCheckingLevelSync();
volatile char* p = reinterpret_cast<char*>(CreateTagMapping());
p[320] = 0; // Untagged pointer, tagged memory.
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(result, R"(Memory tags around the fault address.*
\s*0x[0-9a-f]+: 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0
\s*=>0x[0-9a-f]+: 1 0 1 0 \[1\] 0 1 0 1 0 1 0 1 0 1 0
\s*0x[0-9a-f]+: 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0
)");
#else
GTEST_SKIP() << "Requires aarch64";
#endif
}
TEST_F(CrasherTest, mte_fault_tag_dump_rear_truncated) {
#if defined(__aarch64__)
if (!mte_supported()) {
GTEST_SKIP() << "Requires MTE";
}
int intercept_result;
unique_fd output_fd;
StartProcess([&]() {
SetTagCheckingLevelSync();
size_t page_size = getpagesize();
volatile char* p = reinterpret_cast<char*>(CreateTagMapping());
p[page_size - kTagGranuleSize * 2] = 0; // Untagged pointer, tagged memory.
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(result, R"(Memory tags around the fault address)");
ASSERT_MATCH(result,
R"(\s*0x[0-9a-f]+: 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0
\s*=>0x[0-9a-f]+: 1 0 1 0 1 0 1 0 1 0 1 0 1 0 \[1\] 0
)"); // Ensure truncation happened and there's a newline after the tag fault.
#else
GTEST_SKIP() << "Requires aarch64";
#endif
}
TEST_F(CrasherTest, LD_PRELOAD) {
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
setenv("LD_PRELOAD", "nonexistent.so", 1);
*reinterpret_cast<volatile char*>(0xdead) = '1';
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(result, R"(signal 11 \(SIGSEGV\), code 1 \(SEGV_MAPERR\), fault addr 0xdead)");
}
TEST_F(CrasherTest, abort) {
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
abort();
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGABRT);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_BACKTRACE_FRAME(result, "abort");
}
TEST_F(CrasherTest, signal) {
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
while (true) {
sleep(1);
}
});
StartIntercept(&output_fd);
FinishCrasher();
ASSERT_EQ(0, kill(crasher_pid, SIGSEGV));
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(
result,
R"(signal 11 \(SIGSEGV\), code 0 \(SI_USER from pid \d+, uid \d+\), fault addr --------)");
ASSERT_MATCH(result, R"(backtrace:)");
}
TEST_F(CrasherTest, abort_message) {
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
// Arrived at experimentally;
// logd truncates at 4062.
// strlen("Abort message: ''") is 17.
// That's 4045, but we also want a NUL.
char buf[4045 + 1];
memset(buf, 'x', sizeof(buf));
buf[sizeof(buf) - 1] = '\0';
android_set_abort_message(buf);
abort();
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGABRT);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(result, R"(Abort message: 'x{4045}')");
}
TEST_F(CrasherTest, abort_message_backtrace) {
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
android_set_abort_message("not actually aborting");
raise(BIONIC_SIGNAL_DEBUGGER);
exit(0);
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(0);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_NOT_MATCH(result, R"(Abort message:)");
}
TEST_F(CrasherTest, intercept_timeout) {
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
abort();
});
StartIntercept(&output_fd);
// Don't let crasher finish until we timeout.
FinishIntercept(&intercept_result);
ASSERT_NE(1, intercept_result) << "tombstoned reported success? (intercept_result = "
<< intercept_result << ")";
FinishCrasher();
AssertDeath(SIGABRT);
}
TEST_F(CrasherTest, wait_for_debugger) {
if (!android::base::SetProperty(kWaitForDebuggerKey, "1")) {
FAIL() << "failed to enable wait_for_debugger";
}
sleep(1);
StartProcess([]() {
abort();
});
FinishCrasher();
int status;
ASSERT_EQ(crasher_pid, TEMP_FAILURE_RETRY(waitpid(crasher_pid, &status, WUNTRACED)));
ASSERT_TRUE(WIFSTOPPED(status));
ASSERT_EQ(SIGSTOP, WSTOPSIG(status));
ASSERT_EQ(0, kill(crasher_pid, SIGCONT));
AssertDeath(SIGABRT);
}
TEST_F(CrasherTest, backtrace) {
std::string result;
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
abort();
});
StartIntercept(&output_fd, kDebuggerdNativeBacktrace);
std::this_thread::sleep_for(500ms);
sigval val;
val.sival_int = 1;
ASSERT_EQ(0, sigqueue(crasher_pid, BIONIC_SIGNAL_DEBUGGER, val)) << strerror(errno);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
ConsumeFd(std::move(output_fd), &result);
ASSERT_BACKTRACE_FRAME(result, "read");
int status;
ASSERT_EQ(0, waitpid(crasher_pid, &status, WNOHANG | WUNTRACED));
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGABRT);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
ConsumeFd(std::move(output_fd), &result);
ASSERT_BACKTRACE_FRAME(result, "abort");
}
TEST_F(CrasherTest, PR_SET_DUMPABLE_0_crash) {
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
prctl(PR_SET_DUMPABLE, 0);
abort();
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGABRT);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_BACKTRACE_FRAME(result, "abort");
}
TEST_F(CrasherTest, capabilities) {
ASSERT_EQ(0U, getuid()) << "capability test requires root";
StartProcess([]() {
if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) != 0) {
err(1, "failed to set PR_SET_KEEPCAPS");
}
if (setresuid(1, 1, 1) != 0) {
err(1, "setresuid failed");
}
__user_cap_header_struct capheader;
__user_cap_data_struct capdata[2];
memset(&capheader, 0, sizeof(capheader));
memset(&capdata, 0, sizeof(capdata));
capheader.version = _LINUX_CAPABILITY_VERSION_3;
capheader.pid = 0;
// Turn on every third capability.
static_assert(CAP_LAST_CAP > 33, "CAP_LAST_CAP <= 32");
for (int i = 0; i < CAP_LAST_CAP; i += 3) {
capdata[CAP_TO_INDEX(i)].permitted |= CAP_TO_MASK(i);
capdata[CAP_TO_INDEX(i)].effective |= CAP_TO_MASK(i);
}
// Make sure CAP_SYS_PTRACE is off.
capdata[CAP_TO_INDEX(CAP_SYS_PTRACE)].permitted &= ~(CAP_TO_MASK(CAP_SYS_PTRACE));
capdata[CAP_TO_INDEX(CAP_SYS_PTRACE)].effective &= ~(CAP_TO_MASK(CAP_SYS_PTRACE));
if (capset(&capheader, &capdata[0]) != 0) {
err(1, "capset failed");
}
if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0, 0, 0) != 0) {
err(1, "failed to drop ambient capabilities");
}
pthread_setname_np(pthread_self(), "thread_name");
raise(SIGSYS);
});
unique_fd output_fd;
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSYS);
std::string result;
int intercept_result;
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(result, R"(name: thread_name\s+>>> .+debuggerd_test(32|64) <<<)");
ASSERT_BACKTRACE_FRAME(result, "tgkill");
}
TEST_F(CrasherTest, fake_pid) {
int intercept_result;
unique_fd output_fd;
// Prime the getpid/gettid caches.
UNUSED(getpid());
UNUSED(gettid());
std::function<pid_t()> clone_fn = []() {
return syscall(__NR_clone, SIGCHLD, nullptr, nullptr, nullptr, nullptr);
};
StartProcess(
[]() {
ASSERT_NE(getpid(), syscall(__NR_getpid));
ASSERT_NE(gettid(), syscall(__NR_gettid));
raise(SIGSEGV);
},
clone_fn);
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_BACKTRACE_FRAME(result, "tgkill");
}
static const char* const kDebuggerdSeccompPolicy =
"/system/etc/seccomp_policy/crash_dump." ABI_STRING ".policy";
static pid_t seccomp_fork_impl(void (*prejail)()) {
std::string policy;
if (!android::base::ReadFileToString(kDebuggerdSeccompPolicy, &policy)) {
PLOG(FATAL) << "failed to read policy file";
}
// Allow a bunch of syscalls used by the tests.
policy += "\nclone: 1";
policy += "\nsigaltstack: 1";
policy += "\nnanosleep: 1";
policy += "\ngetrlimit: 1";
policy += "\nugetrlimit: 1";
FILE* tmp_file = tmpfile();
if (!tmp_file) {
PLOG(FATAL) << "tmpfile failed";
}
unique_fd tmp_fd(TEMP_FAILURE_RETRY(dup(fileno(tmp_file))));
if (!android::base::WriteStringToFd(policy, tmp_fd.get())) {
PLOG(FATAL) << "failed to write policy to tmpfile";
}
if (lseek(tmp_fd.get(), 0, SEEK_SET) != 0) {
PLOG(FATAL) << "failed to seek tmp_fd";
}
ScopedMinijail jail{minijail_new()};
if (!jail) {
LOG(FATAL) << "failed to create minijail";
}
minijail_no_new_privs(jail.get());
minijail_log_seccomp_filter_failures(jail.get());
minijail_use_seccomp_filter(jail.get());
minijail_parse_seccomp_filters_from_fd(jail.get(), tmp_fd.release());
pid_t result = fork();
if (result == -1) {
return result;
} else if (result != 0) {
return result;
}
// Spawn and detach a thread that spins forever.
std::atomic<bool> thread_ready(false);
std::thread thread([&jail, &thread_ready]() {
minijail_enter(jail.get());
thread_ready = true;
for (;;)
;
});
thread.detach();
while (!thread_ready) {
continue;
}
if (prejail) {
prejail();
}
minijail_enter(jail.get());
return result;
}
static pid_t seccomp_fork() {
return seccomp_fork_impl(nullptr);
}
TEST_F(CrasherTest, seccomp_crash) {
int intercept_result;
unique_fd output_fd;
StartProcess([]() { abort(); }, &seccomp_fork);
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGABRT);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_BACKTRACE_FRAME(result, "abort");
}
static pid_t seccomp_fork_rlimit() {
return seccomp_fork_impl([]() {
struct rlimit rlim = {
.rlim_cur = 512 * 1024 * 1024,
.rlim_max = 512 * 1024 * 1024,
};
if (setrlimit(RLIMIT_AS, &rlim) != 0) {
raise(SIGINT);
}
});
}
TEST_F(CrasherTest, seccomp_crash_oom) {
int intercept_result;
unique_fd output_fd;
StartProcess(
[]() {
std::vector<void*> vec;
for (int i = 0; i < 512; ++i) {
char* buf = static_cast<char*>(malloc(1024 * 1024));
if (!buf) {
abort();
}
memset(buf, 0xff, 1024 * 1024);
vec.push_back(buf);
}
},
&seccomp_fork_rlimit);
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGABRT);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
// We can't actually generate a backtrace, just make sure that the process terminates.
}
__attribute__((noinline)) extern "C" bool raise_debugger_signal(DebuggerdDumpType dump_type) {
siginfo_t siginfo;
siginfo.si_code = SI_QUEUE;
siginfo.si_pid = getpid();
siginfo.si_uid = getuid();
if (dump_type != kDebuggerdNativeBacktrace && dump_type != kDebuggerdTombstone) {
PLOG(FATAL) << "invalid dump type";
}
siginfo.si_value.sival_int = dump_type == kDebuggerdNativeBacktrace;
if (syscall(__NR_rt_tgsigqueueinfo, getpid(), gettid(), BIONIC_SIGNAL_DEBUGGER, &siginfo) != 0) {
PLOG(ERROR) << "libdebuggerd_client: failed to send signal to self";
return false;
}
return true;
}
TEST_F(CrasherTest, seccomp_tombstone) {
int intercept_result;
unique_fd output_fd;
static const auto dump_type = kDebuggerdTombstone;
StartProcess(
[]() {
raise_debugger_signal(dump_type);
_exit(0);
},
&seccomp_fork);
StartIntercept(&output_fd, dump_type);
FinishCrasher();
AssertDeath(0);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_BACKTRACE_FRAME(result, "raise_debugger_signal");
}
extern "C" void foo() {
LOG(INFO) << "foo";
std::this_thread::sleep_for(1s);
}
extern "C" void bar() {
LOG(INFO) << "bar";
std::this_thread::sleep_for(1s);
}
TEST_F(CrasherTest, seccomp_backtrace) {
int intercept_result;
unique_fd output_fd;
static const auto dump_type = kDebuggerdNativeBacktrace;
StartProcess(
[]() {
std::thread a(foo);
std::thread b(bar);
std::this_thread::sleep_for(100ms);
raise_debugger_signal(dump_type);
_exit(0);
},
&seccomp_fork);
StartIntercept(&output_fd, dump_type);
FinishCrasher();
AssertDeath(0);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_BACKTRACE_FRAME(result, "raise_debugger_signal");
ASSERT_BACKTRACE_FRAME(result, "foo");
ASSERT_BACKTRACE_FRAME(result, "bar");
}
TEST_F(CrasherTest, seccomp_crash_logcat) {
StartProcess([]() { abort(); }, &seccomp_fork);
FinishCrasher();
// Make sure we don't get SIGSYS when trying to dump a crash to logcat.
AssertDeath(SIGABRT);
}
TEST_F(CrasherTest, competing_tracer) {
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
raise(SIGABRT);
});
StartIntercept(&output_fd);
ASSERT_EQ(0, ptrace(PTRACE_SEIZE, crasher_pid, 0, 0));
FinishCrasher();
int status;
ASSERT_EQ(crasher_pid, TEMP_FAILURE_RETRY(waitpid(crasher_pid, &status, 0)));
ASSERT_TRUE(WIFSTOPPED(status));
ASSERT_EQ(SIGABRT, WSTOPSIG(status));
ASSERT_EQ(0, ptrace(PTRACE_CONT, crasher_pid, 0, SIGABRT));
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
std::string regex = R"(failed to attach to thread \d+, already traced by )";
regex += std::to_string(gettid());
regex += R"( \(.+debuggerd_test)";
ASSERT_MATCH(result, regex.c_str());
ASSERT_EQ(crasher_pid, TEMP_FAILURE_RETRY(waitpid(crasher_pid, &status, 0)));
ASSERT_TRUE(WIFSTOPPED(status));
ASSERT_EQ(SIGABRT, WSTOPSIG(status));
ASSERT_EQ(0, ptrace(PTRACE_DETACH, crasher_pid, 0, SIGABRT));
AssertDeath(SIGABRT);
}
TEST_F(CrasherTest, fdsan_warning_abort_message) {
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
android_fdsan_set_error_level(ANDROID_FDSAN_ERROR_LEVEL_WARN_ONCE);
unique_fd fd(TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY | O_CLOEXEC)));
if (fd == -1) {
abort();
}
close(fd.get());
_exit(0);
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(0);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(result, "Abort message: 'attempted to close");
}
TEST(crash_dump, zombie) {
pid_t forkpid = fork();
pid_t rc;
int status;
if (forkpid == 0) {
errno = 0;
rc = waitpid(-1, &status, WNOHANG | __WALL | __WNOTHREAD);
if (rc != -1 || errno != ECHILD) {
errx(2, "first waitpid returned %d (%s), expected failure with ECHILD", rc, strerror(errno));
}
raise(BIONIC_SIGNAL_DEBUGGER);
errno = 0;
rc = TEMP_FAILURE_RETRY(waitpid(-1, &status, __WALL | __WNOTHREAD));
if (rc != -1 || errno != ECHILD) {
errx(2, "second waitpid returned %d (%s), expected failure with ECHILD", rc, strerror(errno));
}
_exit(0);
} else {
rc = TEMP_FAILURE_RETRY(waitpid(forkpid, &status, 0));
ASSERT_EQ(forkpid, rc);
ASSERT_TRUE(WIFEXITED(status));
ASSERT_EQ(0, WEXITSTATUS(status));
}
}
TEST(tombstoned, no_notify) {
// Do this a few times.
for (int i = 0; i < 3; ++i) {
pid_t pid = 123'456'789 + i;
unique_fd intercept_fd, output_fd;
InterceptStatus status;
tombstoned_intercept(pid, &intercept_fd, &output_fd, &status, kDebuggerdTombstone);
ASSERT_EQ(InterceptStatus::kRegistered, status);
{
unique_fd tombstoned_socket, input_fd;
ASSERT_TRUE(tombstoned_connect(pid, &tombstoned_socket, &input_fd, kDebuggerdTombstone));
ASSERT_TRUE(android::base::WriteFully(input_fd.get(), &pid, sizeof(pid)));
}
pid_t read_pid;
ASSERT_TRUE(android::base::ReadFully(output_fd.get(), &read_pid, sizeof(read_pid)));
ASSERT_EQ(read_pid, pid);
}
}
TEST(tombstoned, stress) {
// Spawn threads to simultaneously do a bunch of failing dumps and a bunch of successful dumps.
static constexpr int kDumpCount = 100;
std::atomic<bool> start(false);
std::vector<std::thread> threads;
threads.emplace_back([&start]() {
while (!start) {
continue;
}
// Use a way out of range pid, to avoid stomping on an actual process.
pid_t pid_base = 1'000'000;
for (int dump = 0; dump < kDumpCount; ++dump) {
pid_t pid = pid_base + dump;
unique_fd intercept_fd, output_fd;
InterceptStatus status;
tombstoned_intercept(pid, &intercept_fd, &output_fd, &status, kDebuggerdTombstone);
ASSERT_EQ(InterceptStatus::kRegistered, status);
// Pretend to crash, and then immediately close the socket.
unique_fd sockfd(socket_local_client(kTombstonedCrashSocketName,
ANDROID_SOCKET_NAMESPACE_RESERVED, SOCK_SEQPACKET));
if (sockfd == -1) {
FAIL() << "failed to connect to tombstoned: " << strerror(errno);
}
TombstonedCrashPacket packet = {};
packet.packet_type = CrashPacketType::kDumpRequest;
packet.packet.dump_request.pid = pid;
if (TEMP_FAILURE_RETRY(write(sockfd, &packet, sizeof(packet))) != sizeof(packet)) {
FAIL() << "failed to write to tombstoned: " << strerror(errno);
}
continue;
}
});
threads.emplace_back([&start]() {
while (!start) {
continue;
}
// Use a way out of range pid, to avoid stomping on an actual process.
pid_t pid_base = 2'000'000;
for (int dump = 0; dump < kDumpCount; ++dump) {
pid_t pid = pid_base + dump;
unique_fd intercept_fd, output_fd;
InterceptStatus status;
tombstoned_intercept(pid, &intercept_fd, &output_fd, &status, kDebuggerdTombstone);
ASSERT_EQ(InterceptStatus::kRegistered, status);
{
unique_fd tombstoned_socket, input_fd;
ASSERT_TRUE(tombstoned_connect(pid, &tombstoned_socket, &input_fd, kDebuggerdTombstone));
ASSERT_TRUE(android::base::WriteFully(input_fd.get(), &pid, sizeof(pid)));
tombstoned_notify_completion(tombstoned_socket.get());
}
// TODO: Fix the race that requires this sleep.
std::this_thread::sleep_for(50ms);
pid_t read_pid;
ASSERT_TRUE(android::base::ReadFully(output_fd.get(), &read_pid, sizeof(read_pid)));
ASSERT_EQ(read_pid, pid);
}
});
start = true;
for (std::thread& thread : threads) {
thread.join();
}
}
TEST(tombstoned, java_trace_intercept_smoke) {
// Using a "real" PID is a little dangerous here - if the test fails
// or crashes, we might end up getting a bogus / unreliable stack
// trace.
const pid_t self = getpid();
unique_fd intercept_fd, output_fd;
InterceptStatus status;
tombstoned_intercept(self, &intercept_fd, &output_fd, &status, kDebuggerdJavaBacktrace);
ASSERT_EQ(InterceptStatus::kRegistered, status);
// First connect to tombstoned requesting a native tombstone. This
// should result in a "regular" FD and not the installed intercept.
const char native[] = "native";
unique_fd tombstoned_socket, input_fd;
ASSERT_TRUE(tombstoned_connect(self, &tombstoned_socket, &input_fd, kDebuggerdTombstone));
ASSERT_TRUE(android::base::WriteFully(input_fd.get(), native, sizeof(native)));
tombstoned_notify_completion(tombstoned_socket.get());
// Then, connect to tombstoned asking for a java backtrace. This *should*
// trigger the intercept.
const char java[] = "java";
ASSERT_TRUE(tombstoned_connect(self, &tombstoned_socket, &input_fd, kDebuggerdJavaBacktrace));
ASSERT_TRUE(android::base::WriteFully(input_fd.get(), java, sizeof(java)));
tombstoned_notify_completion(tombstoned_socket.get());
char outbuf[sizeof(java)];
ASSERT_TRUE(android::base::ReadFully(output_fd.get(), outbuf, sizeof(outbuf)));
ASSERT_STREQ("java", outbuf);
}
TEST(tombstoned, multiple_intercepts) {
const pid_t fake_pid = 1'234'567;
unique_fd intercept_fd, output_fd;
InterceptStatus status;
tombstoned_intercept(fake_pid, &intercept_fd, &output_fd, &status, kDebuggerdJavaBacktrace);
ASSERT_EQ(InterceptStatus::kRegistered, status);
unique_fd intercept_fd_2, output_fd_2;
tombstoned_intercept(fake_pid, &intercept_fd_2, &output_fd_2, &status, kDebuggerdNativeBacktrace);
ASSERT_EQ(InterceptStatus::kFailedAlreadyRegistered, status);
}
TEST(tombstoned, intercept_any) {
const pid_t fake_pid = 1'234'567;
unique_fd intercept_fd, output_fd;
InterceptStatus status;
tombstoned_intercept(fake_pid, &intercept_fd, &output_fd, &status, kDebuggerdNativeBacktrace);
ASSERT_EQ(InterceptStatus::kRegistered, status);
const char any[] = "any";
unique_fd tombstoned_socket, input_fd;
ASSERT_TRUE(tombstoned_connect(fake_pid, &tombstoned_socket, &input_fd, kDebuggerdAnyIntercept));
ASSERT_TRUE(android::base::WriteFully(input_fd.get(), any, sizeof(any)));
tombstoned_notify_completion(tombstoned_socket.get());
char outbuf[sizeof(any)];
ASSERT_TRUE(android::base::ReadFully(output_fd.get(), outbuf, sizeof(outbuf)));
ASSERT_STREQ("any", outbuf);
}
TEST(tombstoned, interceptless_backtrace) {
// Generate 50 backtraces, and then check to see that we haven't created 50 new tombstones.
auto get_tombstone_timestamps = []() -> std::map<int, time_t> {
std::map<int, time_t> result;
for (int i = 0; i < 99; ++i) {
std::string path = android::base::StringPrintf("/data/tombstones/tombstone_%02d", i);
struct stat st;
if (stat(path.c_str(), &st) == 0) {
result[i] = st.st_mtim.tv_sec;
}
}
return result;
};
auto before = get_tombstone_timestamps();
for (int i = 0; i < 50; ++i) {
raise_debugger_signal(kDebuggerdNativeBacktrace);
}
auto after = get_tombstone_timestamps();
int diff = 0;
for (int i = 0; i < 99; ++i) {
if (after.count(i) == 0) {
continue;
}
if (before.count(i) == 0) {
++diff;
continue;
}
if (before[i] != after[i]) {
++diff;
}
}
// We can't be sure that nothing's crash looping in the background.
// This should be good enough, though...
ASSERT_LT(diff, 10) << "too many new tombstones; is something crashing in the background?";
}
static __attribute__((__noinline__)) void overflow_stack(void* p) {
void* buf[1];
buf[0] = p;
static volatile void* global = buf;
if (global) {
global = buf;
overflow_stack(&buf);
}
}
TEST_F(CrasherTest, stack_overflow) {
int intercept_result;
unique_fd output_fd;
StartProcess([]() { overflow_stack(nullptr); });
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(result, R"(Cause: stack pointer[^\n]*stack overflow.\n)");
}
static bool CopySharedLibrary(const char* tmp_dir, std::string* tmp_so_name) {
std::string test_lib(testing::internal::GetArgvs()[0]);
auto const value = test_lib.find_last_of('/');
if (value == std::string::npos) {
test_lib = "./";
} else {
test_lib = test_lib.substr(0, value + 1) + "./";
}
test_lib += "libcrash_test.so";
*tmp_so_name = std::string(tmp_dir) + "/libcrash_test.so";
std::string cp_cmd = android::base::StringPrintf("cp %s %s", test_lib.c_str(), tmp_dir);
// Copy the shared so to a tempory directory.
return system(cp_cmd.c_str()) == 0;
}
TEST_F(CrasherTest, unreadable_elf) {
int intercept_result;
unique_fd output_fd;
StartProcess([]() {
TemporaryDir td;
std::string tmp_so_name;
if (!CopySharedLibrary(td.path, &tmp_so_name)) {
_exit(1);
}
void* handle = dlopen(tmp_so_name.c_str(), RTLD_NOW);
if (handle == nullptr) {
_exit(1);
}
// Delete the original shared library so that we get the warning
// about unreadable elf files.
if (unlink(tmp_so_name.c_str()) == -1) {
_exit(1);
}
void (*crash_func)() = reinterpret_cast<void (*)()>(dlsym(handle, "crash"));
if (crash_func == nullptr) {
_exit(1);
}
crash_func();
});
StartIntercept(&output_fd);
FinishCrasher();
AssertDeath(SIGSEGV);
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_MATCH(result, R"(NOTE: Function names and BuildId information is missing )");
}
TEST(tombstoned, proto) {
const pid_t self = getpid();
unique_fd tombstoned_socket, text_fd, proto_fd;
ASSERT_TRUE(
tombstoned_connect(self, &tombstoned_socket, &text_fd, &proto_fd, kDebuggerdTombstoneProto));
tombstoned_notify_completion(tombstoned_socket.get());
ASSERT_NE(-1, text_fd.get());
ASSERT_NE(-1, proto_fd.get());
struct stat text_st;
ASSERT_EQ(0, fstat(text_fd.get(), &text_st));
// Give tombstoned some time to link the files into place.
std::this_thread::sleep_for(100ms);
// Find the tombstone.
std::optional<std::string> tombstone_file;
std::unique_ptr<DIR, decltype(&closedir)> dir_h(opendir("/data/tombstones"), closedir);
ASSERT_TRUE(dir_h != nullptr);
std::regex tombstone_re("tombstone_\\d+");
dirent* entry;
while ((entry = readdir(dir_h.get())) != nullptr) {
if (!std::regex_match(entry->d_name, tombstone_re)) {
continue;
}
std::string path = android::base::StringPrintf("/data/tombstones/%s", entry->d_name);
struct stat st;
if (TEMP_FAILURE_RETRY(stat(path.c_str(), &st)) != 0) {
continue;
}
if (st.st_dev == text_st.st_dev && st.st_ino == text_st.st_ino) {
tombstone_file = path;
break;
}
}
ASSERT_TRUE(tombstone_file);
std::string proto_path = tombstone_file.value() + ".pb";
struct stat proto_fd_st;
struct stat proto_file_st;
ASSERT_EQ(0, fstat(proto_fd.get(), &proto_fd_st));
ASSERT_EQ(0, stat(proto_path.c_str(), &proto_file_st));
ASSERT_EQ(proto_fd_st.st_dev, proto_file_st.st_dev);
ASSERT_EQ(proto_fd_st.st_ino, proto_file_st.st_ino);
}
TEST(tombstoned, proto_intercept) {
const pid_t self = getpid();
unique_fd intercept_fd, output_fd;
InterceptStatus status;
tombstoned_intercept(self, &intercept_fd, &output_fd, &status, kDebuggerdTombstone);
ASSERT_EQ(InterceptStatus::kRegistered, status);
unique_fd tombstoned_socket, text_fd, proto_fd;
ASSERT_TRUE(
tombstoned_connect(self, &tombstoned_socket, &text_fd, &proto_fd, kDebuggerdTombstoneProto));
ASSERT_TRUE(android::base::WriteStringToFd("foo", text_fd.get()));
tombstoned_notify_completion(tombstoned_socket.get());
text_fd.reset();
std::string output;
ASSERT_TRUE(android::base::ReadFdToString(output_fd, &output));
ASSERT_EQ("foo", output);
}
// Verify that when an intercept is present for the main thread, and the signal
// is received on a different thread, the intercept still works.
TEST_F(CrasherTest, intercept_for_main_thread_signal_on_side_thread) {
StartProcess([]() {
std::thread thread([]() {
// Raise the signal on the side thread.
raise_debugger_signal(kDebuggerdNativeBacktrace);
});
thread.join();
_exit(0);
});
unique_fd output_fd;
StartIntercept(&output_fd, kDebuggerdNativeBacktrace);
FinishCrasher();
AssertDeath(0);
int intercept_result;
FinishIntercept(&intercept_result);
ASSERT_EQ(1, intercept_result) << "tombstoned reported failure";
std::string result;
ConsumeFd(std::move(output_fd), &result);
ASSERT_BACKTRACE_FRAME(result, "raise_debugger_signal");
}
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