Merge tag 'perf-core-for-mingo-5.1-20190321' of git://git.kernel.org/pub/scm/linux...

[linux-2.6-microblaze.git] / drivers / connector / cn_proc.c

diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c
index ed5e424..ad48fd5 100644 (file)
--- a/drivers/connector/cn_proc.c
+++ b/drivers/connector/cn_proc.c
@@ -250,6 +250,7 @@ void proc_coredump_connector(struct task_struct *task)
 {
        struct cn_msg *msg;
        struct proc_event *ev;
+       struct task_struct *parent;
        __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
 
        if (atomic_read(&proc_event_num_listeners) < 1)
@@ -262,8 +263,14 @@ void proc_coredump_connector(struct task_struct *task)
        ev->what = PROC_EVENT_COREDUMP;
        ev->event_data.coredump.process_pid = task->pid;
        ev->event_data.coredump.process_tgid = task->tgid;
-       ev->event_data.coredump.parent_pid = task->real_parent->pid;
-       ev->event_data.coredump.parent_tgid = task->real_parent->tgid;
+
+       rcu_read_lock();
+       if (pid_alive(task)) {
+               parent = rcu_dereference(task->real_parent);
+               ev->event_data.coredump.parent_pid = parent->pid;
+               ev->event_data.coredump.parent_tgid = parent->tgid;
+       }
+       rcu_read_unlock();
 
        memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
        msg->ack = 0; /* not used */
@@ -276,6 +283,7 @@ void proc_exit_connector(struct task_struct *task)
 {
        struct cn_msg *msg;
        struct proc_event *ev;
+       struct task_struct *parent;
        __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
 
        if (atomic_read(&proc_event_num_listeners) < 1)
@@ -290,8 +298,14 @@ void proc_exit_connector(struct task_struct *task)
        ev->event_data.exit.process_tgid = task->tgid;
        ev->event_data.exit.exit_code = task->exit_code;
        ev->event_data.exit.exit_signal = task->exit_signal;
-       ev->event_data.exit.parent_pid = task->real_parent->pid;
-       ev->event_data.exit.parent_tgid = task->real_parent->tgid;
+
+       rcu_read_lock();
+       if (pid_alive(task)) {
+               parent = rcu_dereference(task->real_parent);
+               ev->event_data.exit.parent_pid = parent->pid;
+               ev->event_data.exit.parent_tgid = parent->tgid;
+       }
+       rcu_read_unlock();
 
        memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
        msg->ack = 0; /* not used */