This is a note to let you know that I've just added the patch titled

dma-buf: fix reservation_object_wait_timeout_rcu once more v2

to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: dma-buf-fix-reservation_object_wait_timeout_rcu-once-more-v2.patch and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 5bffee867df7494ecd32c1e6ec4e8fc934c521b7 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Christian=20K=C3=B6nig?= ckoenig.leichtzumerken@gmail.com Date: Mon, 22 Jan 2018 21:00:03 +0100 Subject: dma-buf: fix reservation_object_wait_timeout_rcu once more v2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

From: Christian König ckoenig.leichtzumerken@gmail.com

commit 5bffee867df7494ecd32c1e6ec4e8fc934c521b7 upstream.

We need to set shared_count even if we already have a fence to wait for.

v2: init i to -1 as well

Signed-off-by: Christian König christian.koenig@amd.com Cc: stable@vger.kernel.org Tested-by: Lyude Paul lyude@redhat.com Reviewed-by: Lyude Paul lyude@redhat.com Reviewed-by: Chris Wilson chris@chris-wilson.co.uk Signed-off-by: Alex Deucher alexander.deucher@amd.com Link: https://patchwork.freedesktop.org/patch/msgid/20180122200003.6665-1-christia... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/dma-buf/reservation.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/dma-buf/reservation.c +++ b/drivers/dma-buf/reservation.c @@ -455,13 +455,15 @@ long reservation_object_wait_timeout_rcu unsigned long timeout) { struct dma_fence *fence; - unsigned seq, shared_count, i = 0; + unsigned seq, shared_count; long ret = timeout ? timeout : 1; + int i;

retry: shared_count = 0; seq = read_seqcount_begin(&obj->seq); rcu_read_lock(); + i = -1;

fence = rcu_dereference(obj->fence_excl); if (fence && !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) { @@ -477,14 +479,14 @@ retry: fence = NULL; }

- if (!fence && wait_all) { + if (wait_all) { struct reservation_object_list *fobj = rcu_dereference(obj->fence);

if (fobj) shared_count = fobj->shared_count;

- for (i = 0; i < shared_count; ++i) { + for (i = 0; !fence && i < shared_count; ++i) { struct dma_fence *lfence = rcu_dereference(fobj->shared[i]);

if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,

Patches currently in stable-queue which might be from ckoenig.leichtzumerken@gmail.com are

queue-4.15/dma-buf-fix-reservation_object_wait_timeout_rcu-once-more-v2.patch queue-4.15/swiotlb-suppress-warning-when-__gfp_nowarn-is-set.patch