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>

diff --git a/fs/9p/mux.c b/fs/9p/mux.c
index 147ceef8e5370ad3a57c3b87c027bcb08d95bbac..c783874a9cafb3b55080d99eed02ce03c4b4b148 100644 (file)
--- 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);