From: Mikko Perttunen Date: Mon, 29 Mar 2021 13:38:35 +0000 (+0300) Subject: gpu: host1x: Assign intr waiter inside lock X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=5a8d95d20c406c673258edd4c2bd308c22304657;p=linux.git gpu: host1x: Assign intr waiter inside lock Move the assignment of the ref out-pointer in host1x_intr_add_action to happen within the spinlock. With the current arrangement, it is possible for the waiter to complete before the assignment has happened, which breaks horribly if the waiter completion callback tries to use the reference. In practice, there is currently no situation where this issue can manifest -- it was first noticed with the upcoming DMA fence implementation patches. As such this doesn't need to be backported. Signed-off-by: Mikko Perttunen Signed-off-by: Thierry Reding --- diff --git a/drivers/gpu/host1x/intr.c b/drivers/gpu/host1x/intr.c index 69b0e8e41466c..6d1f3c0fdbe77 100644 --- a/drivers/gpu/host1x/intr.c +++ b/drivers/gpu/host1x/intr.c @@ -235,10 +235,11 @@ int host1x_intr_add_action(struct host1x *host, struct host1x_syncpt *syncpt, host1x_hw_intr_enable_syncpt_intr(host, syncpt->id); } - spin_unlock(&syncpt->intr.lock); - if (ref) *ref = waiter; + + spin_unlock(&syncpt->intr.lock); + return 0; }