Userspace doesn't know about PF_USER_WORKER threads, so it can't do wait to clean them up. For cases like where qemu will do dynamic/hot add/remove of vhost devices, then we need to auto reap the thread like was done for the kthread case, because qemu does not know what API the kernel/vhost layer is using. This has us do autoreaping for these threads similar to when the parent ignores SIGCHLD and for kthreads. Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx> --- kernel/signal.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index 7c4b7ae714d4..07e7d6f9bf66 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2049,9 +2049,9 @@ bool do_notify_parent(struct task_struct *tsk, int sig) psig = tsk->parent->sighand; spin_lock_irqsave(&psig->siglock, flags); - if (!tsk->ptrace && sig == SIGCHLD && + if (!tsk->ptrace && (tsk->flags & PF_USER_WORKER || (sig == SIGCHLD && (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || - (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) { + (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))))) { /* * We are exiting and our parent doesn't care. POSIX.1 * defines special semantics for setting SIGCHLD to SIG_IGN -- 2.25.1 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization