From 745de0436b770e9354b2d0a4fe0613a9cbf52a59 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 29 Jul 2019 21:48:01 +0800 Subject: [PATCH] dma-buf: Discard old fence_excl on retrying get_fences_rcu for realloc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit f5b07b04e5f090a85d1e96938520f2b2b58e4a8e upstream. If we have to drop the seqcount & rcu lock to perform a krealloc, we have to restart the loop. In doing so, be careful not to lose track of the already acquired exclusive fence. Fixes: fedf54132d24 ("dma-buf: Restart reservation_object_get_fences_rcu() after writes") Signed-off-by: Chris Wilson Cc: Daniel Vetter Cc: Maarten Lankhorst Cc: Christian König Cc: Alex Deucher Cc: Sumit Semwal Cc: stable@vger.kernel.org #v4.10 Reviewed-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20190604125323.21396-1-chris@chris-wilson.co.uk Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yang Yingliang --- drivers/dma-buf/reservation.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c index 6c95f61a32e7..49ab09468ba1 100644 --- a/drivers/dma-buf/reservation.c +++ b/drivers/dma-buf/reservation.c @@ -416,6 +416,10 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj, GFP_NOWAIT | __GFP_NOWARN); if (!nshared) { rcu_read_unlock(); + + dma_fence_put(fence_excl); + fence_excl = NULL; + nshared = krealloc(shared, sz, GFP_KERNEL); if (nshared) { shared = nshared; -- GitLab