Merge "lmkd: Track processes using pidfds" (d11c6f7f) · Commits · e / os / android_system_core

lmkd/lmkd.c

+43 −20

Original line number	Diff line number	Diff line
		@@ -144,6 +144,11 @@ static inline int sys_pidfd_open(pid_t pid, unsigned int flags) {
		return syscall(__NR_pidfd_open, pid, flags);
		}

		static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
		unsigned int flags) {
		return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags);
		}

		/* default to old in-kernel interface if no memory pressure events */
		static bool use_inkernel_interface = true;
		static bool has_inkernel_module;
		@@ -482,6 +487,7 @@ struct adjslot_list {
		struct proc {
		struct adjslot_list asl;
		int pid;
		int pidfd;
		uid_t uid;
		int oomadj;
		struct proc *pidhash_next;
		@@ -698,6 +704,13 @@ static int pid_remove(int pid) {
		prevp->pidhash_next = procp->pidhash_next;

		proc_unslot(procp);
		/*
		* Close pidfd here if we are not waiting for corresponding process to die,
		* in which case stop_wait_for_proc_kill() will close the pidfd later
		*/
		if (procp->pidfd >= 0 && procp->pidfd != last_kill_pid_or_fd) {
		close(procp->pidfd);
		}
		free(procp);
		return 0;
		}
		@@ -922,13 +935,24 @@ static void cmd_procprio(LMKD_CTRL_PACKET packet) {

		procp = pid_lookup(params.pid);
		if (!procp) {
		procp = malloc(sizeof(struct proc));
		int pidfd = -1;

		if (pidfd_supported) {
		pidfd = TEMP_FAILURE_RETRY(sys_pidfd_open(params.pid, 0));
		if (pidfd < 0) {
		ALOGE("pidfd_open for pid %d failed; errno=%d", params.pid, errno);
		return;
		}
		}

		procp = calloc(1, sizeof(struct proc));
		if (!procp) {
		// Oh, the irony. May need to rebuild our state.
		return;
		}

		procp->pid = params.pid;
		procp->pidfd = pidfd;
		procp->uid = params.uid;
		procp->oomadj = params.oomadj;
		proc_insert(procp);
		@@ -1733,7 +1757,7 @@ static void kill_done_handler(int data __unused, uint32_t events __unused,
		poll_params->update = POLLING_RESUME;
		}

		static void start_wait_for_proc_kill(int pid) {
		static void start_wait_for_proc_kill(int pid_or_fd) {
		static struct event_handler_info kill_done_hinfo = { 0, kill_done_handler };
		struct epoll_event epev;

		@@ -1743,15 +1767,10 @@ static void start_wait_for_proc_kill(int pid) {
		stop_wait_for_proc_kill(false);
		}

		if (!pidfd_supported) {
		/* If pidfd is not supported store PID of the process being killed */
		last_kill_pid_or_fd = pid;
		return;
		}
		last_kill_pid_or_fd = pid_or_fd;

		last_kill_pid_or_fd = TEMP_FAILURE_RETRY(sys_pidfd_open(pid, 0));
		if (last_kill_pid_or_fd < 0) {
		ALOGE("pidfd_open for process pid %d failed; errno=%d", pid, errno);
		if (!pidfd_supported) {
		/* If pidfd is not supported just store PID and exit */
		return;
		}

		@@ -1770,6 +1789,7 @@ static void start_wait_for_proc_kill(int pid) {
		static int kill_one_process(struct proc* procp, int min_oom_score, int kill_reason,
		const char kill_desc, union meminfo mi, struct timespec *tm) {
		int pid = procp->pid;
		int pidfd = procp->pidfd;
		uid_t uid = procp->uid;
		int tgid;
		char *taskname;
		@@ -1799,11 +1819,14 @@ static int kill_one_process(struct proc* procp, int min_oom_score, int kill_reas

		TRACE_KILL_START(pid);

		/* Have to start waiting before sending SIGKILL to make sure pid is valid */
		start_wait_for_proc_kill(pid);

		/* CAP_KILL required */
		if (pidfd < 0) {
		start_wait_for_proc_kill(pid);
		r = kill(pid, SIGKILL);
		} else {
		start_wait_for_proc_kill(pidfd);
		r = sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0);
		}

		TRACE_KILL_END();