9p: Use kthread_stop instead of sending a SIGKILL.

Since the kthread api does not bump the reference count on
processes that tracked it is not safe allow user space to
kill the threads, as I still retain a pointer to the task_struct.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Eric Van Hensbergen <ericvh@gmail.com>

1 files changed, 1 insertions, 4 deletions

diff --git a/fs/9p/mux.c b/fs/9p/mux.c
index 147ceef8e537..c783874a9caf 100644
--- a/fs/9p/mux.c
+++ b/fs/9p/mux.c
@@ -256,7 +256,7 @@ static void v9fs_mux_poll_stop(struct v9fs_mux_data *m)
         vpt->muxnum--;
         if (!vpt->muxnum) {
                 dprintk(DEBUG_MUX, "destroy proc %p\n", vpt);
-                send_sig(SIGKILL, vpt->task, 1);
+                kthread_stop(vpt->task);
                 vpt->task = NULL;
                 v9fs_mux_poll_task_num--;
         }
@@ -438,11 +438,8 @@ static int v9fs_poll_proc(void *a)
 
         vpt = a;
         dprintk(DEBUG_MUX, "start %p %p\n", current, vpt);
-        allow_signal(SIGKILL);
         while (!kthread_should_stop()) {
                 set_current_state(TASK_INTERRUPTIBLE);
-                if (signal_pending(current))
-                        break;
 
                 list_for_each_entry_safe(m, mtmp, &vpt->mux_list, mux_list) {
                         v9fs_poll_mux(m);