std::vector<std::string> get_paths(const std::string& name, bool resolve, size_t* lineno = nullptr) {
std::string paths_str = get_string(name, lineno);
std::vector<std::string> paths;
split_path(paths_str.c_str(), ":", &paths);
std::vector<std::pair<std::string, std::string>> params;
params.push_back({ "LIB", kLibParamValue });
if (target_sdk_version_ != 0) {
char buf[16];
async_safe_format_buffer(buf, sizeof(buf), "%d", target_sdk_version_);
params.push_back({ "SDK_VER", buf });
}
static std::string vndk = Config::get_vndk_version_string('-');
params.push_back({ "VNDK_VER", vndk });
for (auto&& path : paths) {
format_string(&path, params);
}
if (resolve) {
std::vector<std::string> resolved_paths;
// do not remove paths that do not exist
resolve_paths(paths, &resolved_paths);
return resolved_paths;
} else {
return paths;
}
}
static std::string create_error_msg(const char* file,
size_t lineno,
const std::string& msg) {
char buf[1024];
async_safe_format_buffer(buf, sizeof(buf), "%s:%zu: error: %s", file, lineno, msg.c_str());
return std::string(buf);
}
static int debuggerd_dispatch_pseudothread(void* arg) {
debugger_thread_info* thread_info = static_cast<debugger_thread_info*>(arg);
for (int i = 0; i < 1024; ++i) {
close(i);
}
int devnull = TEMP_FAILURE_RETRY(open("/dev/null", O_RDWR));
// devnull will be 0.
TEMP_FAILURE_RETRY(dup2(devnull, STDOUT_FILENO));
TEMP_FAILURE_RETRY(dup2(devnull, STDERR_FILENO));
int pipefds[2];
if (pipe(pipefds) != 0) {
fatal_errno("failed to create pipe");
}
// Don't use fork(2) to avoid calling pthread_atfork handlers.
int forkpid = clone(nullptr, nullptr, 0, nullptr);
if (forkpid == -1) {
async_safe_format_log(ANDROID_LOG_FATAL, "libc",
"failed to fork in debuggerd signal handler: %s", strerror(errno));
} else if (forkpid == 0) {
TEMP_FAILURE_RETRY(dup2(pipefds[1], STDOUT_FILENO));
close(pipefds[0]);
close(pipefds[1]);
raise_caps();
char main_tid[10];
char pseudothread_tid[10];
char debuggerd_dump_type[10];
async_safe_format_buffer(main_tid, sizeof(main_tid), "%d", thread_info->crashing_tid);
async_safe_format_buffer(pseudothread_tid, sizeof(pseudothread_tid), "%d",
thread_info->pseudothread_tid);
async_safe_format_buffer(debuggerd_dump_type, sizeof(debuggerd_dump_type), "%d",
get_dump_type(thread_info));
execl(CRASH_DUMP_PATH, CRASH_DUMP_NAME, main_tid, pseudothread_tid, debuggerd_dump_type,
nullptr);
fatal_errno("exec failed");
} else {
close(pipefds[1]);
char buf[4];
ssize_t rc = TEMP_FAILURE_RETRY(read(pipefds[0], &buf, sizeof(buf)));
if (rc == -1) {
async_safe_format_log(ANDROID_LOG_FATAL, "libc", "read of IPC pipe failed: %s",
strerror(errno));
} else if (rc == 0) {
async_safe_format_log(ANDROID_LOG_FATAL, "libc", "crash_dump helper failed to exec");
} else if (rc != 1) {
async_safe_format_log(ANDROID_LOG_FATAL, "libc",
"read of IPC pipe returned unexpected value: %zd", rc);
} else {
if (buf[0] != '\1') {
async_safe_format_log(ANDROID_LOG_FATAL, "libc", "crash_dump helper reported failure");
} else {
thread_info->crash_dump_started = true;
}
}
close(pipefds[0]);
// Don't leave a zombie child.
int status;
if (TEMP_FAILURE_RETRY(waitpid(forkpid, &status, 0)) == -1) {
async_safe_format_log(ANDROID_LOG_FATAL, "libc", "failed to wait for crash_dump helper: %s",
strerror(errno));
} else if (WIFSTOPPED(status) || WIFSIGNALED(status)) {
async_safe_format_log(ANDROID_LOG_FATAL, "libc", "crash_dump helper crashed or stopped");
thread_info->crash_dump_started = false;
}
}
syscall(__NR_exit, 0);
return 0;
}
/*
* Writes a summary of the signal to the log file. We do this so that, if
* for some reason we're not able to contact debuggerd, there is still some
* indication of the failure in the log.
*
* We could be here as a result of native heap corruption, or while a
* mutex is being held, so we don't want to use any libc functions that
* could allocate memory or hold a lock.
*/
static void log_signal_summary(int signum, const siginfo_t* info) {
char thread_name[MAX_TASK_NAME_LEN + 1]; // one more for termination
if (prctl(PR_GET_NAME, reinterpret_cast<unsigned long>(thread_name), 0, 0, 0) != 0) {
strcpy(thread_name, "<name unknown>");
} else {
// short names are null terminated by prctl, but the man page
// implies that 16 byte names are not.
thread_name[MAX_TASK_NAME_LEN] = 0;
}
if (signum == DEBUGGER_SIGNAL) {
async_safe_format_log(ANDROID_LOG_INFO, "libc", "Requested dump for tid %d (%s)", __gettid(),
thread_name);
return;
}
const char* signal_name = "???";
bool has_address = false;
switch (signum) {
case SIGABRT:
signal_name = "SIGABRT";
break;
case SIGBUS:
signal_name = "SIGBUS";
has_address = true;
break;
case SIGFPE:
signal_name = "SIGFPE";
has_address = true;
break;
case SIGILL:
signal_name = "SIGILL";
has_address = true;
break;
case SIGSEGV:
signal_name = "SIGSEGV";
has_address = true;
break;
#if defined(SIGSTKFLT)
case SIGSTKFLT:
signal_name = "SIGSTKFLT";
break;
#endif
case SIGSYS:
signal_name = "SIGSYS";
break;
case SIGTRAP:
signal_name = "SIGTRAP";
break;
}
// "info" will be null if the siginfo_t information was not available.
// Many signals don't have an address or a code.
char code_desc[32]; // ", code -6"
char addr_desc[32]; // ", fault addr 0x1234"
addr_desc[0] = code_desc[0] = 0;
if (info != nullptr) {
async_safe_format_buffer(code_desc, sizeof(code_desc), ", code %d", info->si_code);
if (has_address) {
async_safe_format_buffer(addr_desc, sizeof(addr_desc), ", fault addr %p", info->si_addr);
}
}
char main_thread_name[MAX_TASK_NAME_LEN + 1];
if (!get_main_thread_name(main_thread_name, sizeof(main_thread_name))) {
strncpy(main_thread_name, "<unknown>", sizeof(main_thread_name));
}
async_safe_format_log(
ANDROID_LOG_FATAL, "libc", "Fatal signal %d (%s)%s%s in tid %d (%s), pid %d (%s)", signum,
signal_name, code_desc, addr_desc, __gettid(), thread_name, __getpid(), main_thread_name);
}
