Merge "llkd: make 100% sure process that triggers panic still exists" (00289c9c) · Commits · e / os / android_system_core

llkd/libllkd.cpp

+12 −4

Original line number	Original line	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;		return android::base::Trim(content) == string;
	}		}

	void llkPanicKernel(bool dump, pid_t tid, const char* state,		void llkPanicKernel(bool dump, pid_t tid, const char* state, const std::string& message = "") {
	const std::string& message = "") __noreturn;
	void llkPanicKernel(bool dump, pid_t tid, const char* state, const std::string& message) {
	if (!message.empty()) LOG(ERROR) << message;		if (!message.empty()) LOG(ERROR) << message;
	auto sysrqTriggerFd = llkFileToWriteFd("/proc/sysrq-trigger");		auto sysrqTriggerFd = llkFileToWriteFd("/proc/sysrq-trigger");
	if (sysrqTriggerFd < 0) {		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		// The answer to life, the universe and everything
	::exit(42);		::exit(42);
	// NOTREACHED		// NOTREACHED
			return;
	}		}
	::sync();		::sync();
	if (dump) {		if (dump) {
	@@ -544,6 +543,13 @@ void llkPanicKernel(bool dump, pid_t tid, const char* state, const std::string&
	llkWriteStringToFile(message + (message.empty() ? "" : "\n") +		llkWriteStringToFile(message + (message.empty() ? "" : "\n") +
	"SysRq : Trigger a crash : 'livelock,"s + state + "'\n",		"SysRq : Trigger a crash : 'livelock,"s + state + "'\n",
	"/dev/kmsg");		"/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);		android::base::WriteStringToFd("c", sysrqTriggerFd);
	// NOTREACHED		// NOTREACHED
	// DYB		// DYB
	@@ -909,6 +915,7 @@ milliseconds llkCheck(bool checkRunning) {
	ms -= llkCycle;		ms -= llkCycle;
	auto myPid = ::getpid();		auto myPid = ::getpid();
	auto myTid = ::gettid();		auto myTid = ::gettid();
			auto dump = true;
	for (auto dp = llkTopDirectory.read(); dp != nullptr; dp = llkTopDirectory.read()) {		for (auto dp = llkTopDirectory.read(); dp != nullptr; dp = llkTopDirectory.read()) {
	std::string piddir;		std::string piddir;

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