Merge "tombstoned: make missing O_TMPFILE workaround actually work around." (820fec50) · Commits · e / os / android_system_core

debuggerd/tombstoned/tombstoned.cpp

+22 −9

Original line number	Diff line number	Diff line
		@@ -61,6 +61,7 @@ enum CrashStatus {
		struct Crash {
		~Crash() { event_free(crash_event); }

		std::string crash_tombstone_path;
		unique_fd crash_tombstone_fd;
		unique_fd crash_socket_fd;
		pid_t crash_pid;
		@@ -109,20 +110,22 @@ class CrashQueue {
		return &queue;
		}

		unique_fd get_output() {
		std::pair<std::string, unique_fd> get_output() {
		std::string path;
		unique_fd result(openat(dir_fd_, ".", O_WRONLY \| O_APPEND \| O_TMPFILE \| O_CLOEXEC, 0640));
		if (result == -1) {
		// We might not have O_TMPFILE. Try creating and unlinking instead.
		result.reset(
		openat(dir_fd_, ".temporary", O_WRONLY \| O_APPEND \| O_CREAT \| O_TRUNC \| O_CLOEXEC, 0640));
		// We might not have O_TMPFILE. Try creating with an arbitrary filename instead.
		static size_t counter = 0;
		std::string tmp_filename = StringPrintf(".temporary%zu", counter++);
		result.reset(openat(dir_fd_, tmp_filename.c_str(),
		O_WRONLY \| O_APPEND \| O_CREAT \| O_TRUNC \| O_CLOEXEC, 0640));
		if (result == -1) {
		PLOG(FATAL) << "failed to create temporary tombstone in " << dir_path_;
		}
		if (unlinkat(dir_fd_, ".temporary", 0) != 0) {
		PLOG(FATAL) << "failed to unlink temporary tombstone";
		}

		path = StringPrintf("%s/%s", dir_path_.c_str(), tmp_filename.c_str());
		}
		return result;
		return std::make_pair(std::move(path), std::move(result));
		}

		std::string get_next_artifact_path() {
		@@ -209,7 +212,7 @@ static void perform_request(Crash* crash) {
		bool intercepted =
		intercept_manager->GetIntercept(crash->crash_pid, crash->crash_type, &output_fd);
		if (!intercepted) {
		output_fd = CrashQueue::for_crash(crash)->get_output();
		std::tie(crash->crash_tombstone_path, output_fd) = CrashQueue::for_crash(crash)->get_output();
		crash->crash_tombstone_fd.reset(dup(output_fd.get()));
		}

		@@ -351,6 +354,8 @@ static void crash_completed_cb(evutil_socket_t sockfd, short ev, void* arg) {
		if (crash->crash_tombstone_fd != -1) {
		std::string fd_path = StringPrintf("/proc/self/fd/%d", crash->crash_tombstone_fd.get());
		std::string tombstone_path = CrashQueue::for_crash(crash)->get_next_artifact_path();

		// linkat doesn't let us replace a file, so we need to unlink first.
		int rc = unlink(tombstone_path.c_str());
		if (rc != 0 && errno != ENOENT) {
		PLOG(ERROR) << "failed to unlink tombstone at " << tombstone_path;
		@@ -370,6 +375,14 @@ static void crash_completed_cb(evutil_socket_t sockfd, short ev, void* arg) {
		LOG(ERROR) << "Tombstone written to: " << tombstone_path;
		}
		}

		// If we don't have O_TMPFILE, we need to clean up after ourselves.
		if (!crash->crash_tombstone_path.empty()) {
		rc = unlink(crash->crash_tombstone_path.c_str());
		if (rc != 0) {
		PLOG(ERROR) << "failed to unlink temporary tombstone at " << crash->crash_tombstone_path;
		}
		}
		}

		fail: