Revert "crash_dump: defer pausing threads until we're ready." (3407d7c8) · Commits · e / os / android_system_core

debuggerd/Android.bp

+0 −1

Original line number	Diff line number	Diff line
		@@ -7,7 +7,6 @@ cc_defaults {
		"-Wno-nullability-completeness",
		"-Os",
		],
		cpp_std: "experimental",

		local_include_dirs: ["include"],
		}

debuggerd/crash_dump.cpp

+26 −30

Original line number	Diff line number	Diff line
		@@ -95,6 +95,11 @@ static bool ptrace_seize_thread(int pid_proc_fd, pid_t tid, std::string* error)
		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;
		}

		@@ -279,22 +284,19 @@ int main(int argc, char** argv) {
		// Die if we take too long.
		alarm(2);

		std::string process_name = get_process_name(main_tid);
		std::string attach_error;

		std::map<pid_t, std::string> threads;

		{
		ATRACE_NAME("ptrace_interrupt");

		ATRACE_NAME("ptrace");
		// Seize the main thread.
		if (!ptrace_seize_thread(target_proc_fd, main_tid, &attach_error)) {
		LOG(FATAL) << attach_error;
		}

		threads.emplace(main_tid, get_thread_name(main_tid));

		// Seize its siblings.
		// Seize the siblings.
		{
		std::set<pid_t> siblings;
		if (!android::procinfo::GetProcessTids(target, &siblings)) {
		PLOG(FATAL) << "failed to get process siblings";
		@@ -308,11 +310,12 @@ int main(int argc, char** argv) {
		for (pid_t sibling_tid : siblings) {
		if (!ptrace_seize_thread(target_proc_fd, sibling_tid, &attach_error)) {
		LOG(WARNING) << attach_error;
		continue;
		}
		} else {
		threads.emplace(sibling_tid, get_thread_name(sibling_tid));
		}
		}
		}
		}

		// Collect the backtrace map, open files, and process/thread names, while we still have caps.
		std::unique_ptr<BacktraceMap> backtrace_map;
		@@ -331,6 +334,9 @@ int main(int argc, char** argv) {
		populate_open_files_list(target, &open_files);
		}

		std::string process_name = get_process_name(main_tid);
		threads.emplace(main_tid, get_thread_name(main_tid));

		// Drop our capabilities now that we've attached to the threads we care about.
		drop_capabilities();

		@@ -341,16 +347,6 @@ int main(int argc, char** argv) {
		tombstoned_connected = tombstoned_connect(target, &tombstoned_socket, &output_fd, dump_type_enum);
		}

		// Pause the threads.
		{
		ATRACE_NAME("ptrace_interrupt");
		for (const auto& [sibling_tid, _] : threads) {
		if (ptrace(PTRACE_INTERRUPT, sibling_tid, 0, 0) != 0) {
		PLOG(FATAL) << "failed to interrupt thread " << sibling_tid;
		}
		}
		}

		// Write a '\1' to stdout to tell the crashing process to resume.
		// It also restores the value of PR_SET_DUMPABLE at this point.
		if (TEMP_FAILURE_RETRY(write(STDOUT_FILENO, "\1", 1)) == -1) {