Merge "llkd: make 100% sure process that triggers panic still exists" am: 00289c9c79 (b9f4845c) · Commits · e / os / android_system_core

llkd/libllkd.cpp

+12 −4

Original line number	Diff line number	Diff line
		@@ -510,9 +510,7 @@ bool llkWriteStringToFileConfirm(const std::string& string, const std::string& f
		return android::base::Trim(content) == string;
		}

		void llkPanicKernel(bool dump, pid_t tid, const char* state,
		const std::string& message = "") __noreturn;
		void llkPanicKernel(bool dump, pid_t tid, const char* state, const std::string& message) {
		void llkPanicKernel(bool dump, pid_t tid, const char* state, const std::string& message = "") {
		if (!message.empty()) LOG(ERROR) << message;
		auto sysrqTriggerFd = llkFileToWriteFd("/proc/sysrq-trigger");
		if (sysrqTriggerFd < 0) {
		@@ -521,6 +519,7 @@ void llkPanicKernel(bool dump, pid_t tid, const char* state, const std::string&
		// The answer to life, the universe and everything
		::exit(42);
		// NOTREACHED
		return;
		}
		::sync();
		if (dump) {
		@@ -544,6 +543,13 @@ void llkPanicKernel(bool dump, pid_t tid, const char* state, const std::string&
		llkWriteStringToFile(message + (message.empty() ? "" : "\n") +
		"SysRq : Trigger a crash : 'livelock,"s + state + "'\n",
		"/dev/kmsg");
		// Because panic is such a serious thing to do, let us
		// make sure that the tid being inspected still exists!
		auto piddir = procdir + std::to_string(tid) + "/stat";
		if (access(piddir.c_str(), F_OK) != 0) {
		PLOG(WARNING) << piddir;
		return;
		}
		android::base::WriteStringToFd("c", sysrqTriggerFd);
		// NOTREACHED
		// DYB
		@@ -909,6 +915,7 @@ milliseconds llkCheck(bool checkRunning) {
		ms -= llkCycle;
		auto myPid = ::getpid();
		auto myTid = ::gettid();
		auto dump = true;
		for (auto dp = llkTopDirectory.read(); dp != nullptr; dp = llkTopDirectory.read()) {
		std::string piddir;

		@@ -1109,9 +1116,10 @@ milliseconds llkCheck(bool checkRunning) {
		const auto message = state + " "s + llkFormat(procp->count) + " " +
		std::to_string(ppid) + "->" + std::to_string(pid) + "->" +
		std::to_string(tid) + " " + procp->getComm() + " [panic]";
		llkPanicKernel(true, tid,
		llkPanicKernel(dump, tid,
		(state == 'Z') ? "zombie" : (state == 'D') ? "driver" : "sleeping",
		message);
		dump = false;
		}
		LOG(VERBOSE) << "+closedir()";
		}