From: Oliver Hartkopp <socketcan@hartkopp.net>
Date: Wed, 18 Jan 2017 20:30:51 +0000 (+0100)
Subject: can: bcm: fix hrtimer/tasklet termination in bcm op removal
X-Git-Tag: v3.10.107~237
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d5361ee850ef3e69a92883e46ccbb5ed6ccb9323;p=thirdparty%2Fkernel%2Fstable.git

can: bcm: fix hrtimer/tasklet termination in bcm op removal

commit a06393ed03167771246c4c43192d9c264bc48412 upstream.

When removing a bcm tx operation either a hrtimer or a tasklet might run.
As the hrtimer triggers its associated tasklet and vice versa we need to
take care to mutually terminate both handlers.

Reported-by: Michael Josenhans <michael.josenhans@web.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Tested-by: Michael Josenhans <michael.josenhans@web.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---

diff --git a/net/can/bcm.c b/net/can/bcm.c
index 725ce812cfbc3..6e0a88d9c554b 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -706,14 +706,23 @@ static struct bcm_op *bcm_find_op(struct list_head *ops, canid_t can_id,
 
 static void bcm_remove_op(struct bcm_op *op)
 {
-	hrtimer_cancel(&op->timer);
-	hrtimer_cancel(&op->thrtimer);
-
-	if (op->tsklet.func)
-		tasklet_kill(&op->tsklet);
+	if (op->tsklet.func) {
+		while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) ||
+		       test_bit(TASKLET_STATE_RUN, &op->tsklet.state) ||
+		       hrtimer_active(&op->timer)) {
+			hrtimer_cancel(&op->timer);
+			tasklet_kill(&op->tsklet);
+		}
+	}
 
-	if (op->thrtsklet.func)
-		tasklet_kill(&op->thrtsklet);
+	if (op->thrtsklet.func) {
+		while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) ||
+		       test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) ||
+		       hrtimer_active(&op->thrtimer)) {
+			hrtimer_cancel(&op->thrtimer);
+			tasklet_kill(&op->thrtsklet);
+		}
+	}
 
 	if ((op->frames) && (op->frames != &op->sframe))
 		kfree(op->frames);