Merge remote-tracking branch 'remotes/stable/linux-4.4.y' into karo-tx6-mainline

[karo-tx-linux.git] / kernel / exit.c

diff --git a/kernel/exit.c b/kernel/exit.c
index 07110c6020a04ea37c04bc18bd0b9287cd0466dc..ffba5df4abd54cd2dc146a09fa152ed84502e213 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -918,17 +918,28 @@ static int eligible_pid(struct wait_opts *wo, struct task_struct *p)
                task_pid_type(p, wo->wo_type) == wo->wo_pid;
 }
 
-static int eligible_child(struct wait_opts *wo, struct task_struct *p)
+static int
+eligible_child(struct wait_opts *wo, bool ptrace, struct task_struct *p)
 {
        if (!eligible_pid(wo, p))
                return 0;
-       /* Wait for all children (clone and not) if __WALL is set;
-        * otherwise, wait for clone children *only* if __WCLONE is
-        * set; otherwise, wait for non-clone children *only*.  (Note:
-        * A "clone" child here is one that reports to its parent
-        * using a signal other than SIGCHLD.) */
-       if (((p->exit_signal != SIGCHLD) ^ !!(wo->wo_flags & __WCLONE))
-           && !(wo->wo_flags & __WALL))
+
+       /*
+        * Wait for all children (clone and not) if __WALL is set or
+        * if it is traced by us.
+        */
+       if (ptrace || (wo->wo_flags & __WALL))
+               return 1;
+
+       /*
+        * Otherwise, wait for clone children *only* if __WCLONE is set;
+        * otherwise, wait for non-clone children *only*.
+        *
+        * Note: a "clone" child here is one that reports to its parent
+        * using a signal other than SIGCHLD, or a non-leader thread which
+        * we can only see if it is traced by us.
+        */
+       if ((p->exit_signal != SIGCHLD) ^ !!(wo->wo_flags & __WCLONE))
                return 0;
 
        return 1;
@@ -1301,7 +1312,7 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace,
        if (unlikely(exit_state == EXIT_DEAD))
                return 0;
 
-       ret = eligible_child(wo, p);
+       ret = eligible_child(wo, ptrace, p);
        if (!ret)
                return ret;