crash_dump: switch to PTRACE_SEIZE. am: 122479f4a0 am: 6121036e3a (bef86bcd) · Commits · e / os / android_system_core

debuggerd/crash_dump.cpp

+13 −7

Original line number	Diff line number	Diff line
		@@ -57,8 +57,8 @@ static bool pid_contains_tid(pid_t pid, pid_t tid) {
		}

		// Attach to a thread, and verify that it's still a member of the given process
		static bool ptrace_attach_thread(pid_t pid, pid_t tid, std::string* error) {
		if (ptrace(PTRACE_ATTACH, tid, 0, 0) != 0) {
		static bool ptrace_seize_thread(pid_t pid, pid_t tid, std::string* error) {
		if (ptrace(PTRACE_SEIZE, tid, 0, 0) != 0) {
		*error = StringPrintf("failed to attach to thread %d: %s", tid, strerror(errno));
		return false;
		}
		@@ -71,6 +71,12 @@ static bool ptrace_attach_thread(pid_t pid, pid_t tid, std::string* error) {
		*error = StringPrintf("thread %d is not in process %d", tid, pid);
		return false;
		}

		// Put the task into ptrace-stop state.
		if (ptrace(PTRACE_INTERRUPT, tid, 0, 0) != 0) {
		PLOG(FATAL) << "failed to interrupt thread " << tid;
		}

		return true;
		}

		@@ -254,7 +260,7 @@ int main(int argc, char** argv) {
		check_process(target_proc_fd, target);

		std::string attach_error;
		if (!ptrace_attach_thread(target, main_tid, &attach_error)) {
		if (!ptrace_seize_thread(target, main_tid, &attach_error)) {
		LOG(FATAL) << attach_error;
		}

		@@ -279,9 +285,9 @@ int main(int argc, char** argv) {

		LOG(INFO) << "performing dump of process " << target << " (target tid = " << main_tid << ")";

		// At this point, the thread that made the request has been PTRACE_ATTACHed
		// and has the signal that triggered things queued. Send PTRACE_CONT, and
		// then wait for the signal.
		// At this point, the thread that made the request has been attached and is
		// in ptrace-stopped state. After resumption, the triggering signal that has
		// been queued will be delivered.
		if (ptrace(PTRACE_CONT, main_tid, 0, 0) != 0) {
		PLOG(ERROR) << "PTRACE_CONT(" << main_tid << ") failed";
		exit(1);
		@@ -320,7 +326,7 @@ int main(int argc, char** argv) {
		siblings.erase(main_tid);

		for (pid_t sibling_tid : siblings) {
		if (!ptrace_attach_thread(target, sibling_tid, &attach_error)) {
		if (!ptrace_seize_thread(target, sibling_tid, &attach_error)) {
		LOG(WARNING) << attach_error;
		} else {
		attached_siblings.insert(sibling_tid);