Merge "lmkd: Track processes using pidfds"
am: d11c6f7fd8
Change-Id: I7cf396167954f51d3c7a092b5eebc54826f69f88
diff --git a/lmkd/lmkd.c b/lmkd/lmkd.c
index a5411d8..e286877 100644
--- a/lmkd/lmkd.c
+++ b/lmkd/lmkd.c
@@ -144,6 +144,11 @@
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 proc {
struct adjslot_list asl;
int pid;
+ int pidfd;
uid_t uid;
int oomadj;
struct proc *pidhash_next;
@@ -698,6 +704,13 @@
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;
}
@@ -922,16 +935,27 @@
procp = pid_lookup(params.pid);
if (!procp) {
- procp = malloc(sizeof(struct proc));
- if (!procp) {
- // Oh, the irony. May need to rebuild our state.
+ 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->pid = params.pid;
- procp->uid = params.uid;
- procp->oomadj = params.oomadj;
- proc_insert(procp);
+ 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);
} else {
proc_unslot(procp);
procp->oomadj = params.oomadj;
@@ -1733,7 +1757,7 @@
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 @@
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 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 @@
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 */
- r = kill(pid, SIGKILL);
+ 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();