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

dma-buf/sw_sync: force signal all unsignaled fences on dying timeline

to the 4.9-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-sw_sync-force-signal-all-unsignaled-fences-on-dying-timeline.patch and it can be found in the queue-4.9 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 ea4d5a270b57fa8d4871f372ca9b97b7697fdfda Mon Sep 17 00:00:00 2001

From: Dominik Behr dbehr@chromium.org Date: Thu, 7 Sep 2017 16:02:46 -0300 Subject: dma-buf/sw_sync: force signal all unsignaled fences on dying timeline

From: Dominik Behr dbehr@chromium.org

commit ea4d5a270b57fa8d4871f372ca9b97b7697fdfda upstream.

To avoid hanging userspace components that might have been waiting on the active fences of the destroyed timeline we need to signal with error all remaining fences on such timeline.

This restore the default behaviour of the Android sw_sync framework, which Android still relies on. It was broken on the dma fence conversion a few years ago and never fixed.

v2: Do not bother with cleanup do the list (Chris Wilson)

Reviewed-by: Chris Wilson chris@chris-wilson.co.uk Signed-off-by: Dominik Behr dbehr@chromium.org Signed-off-by: Gustavo Padovan gustavo.padovan@collabora.com Link: https://patchwork.freedesktop.org/patch/msgid/20170907190246.16425-2-gustavo... [s/dma_fence/fence/g - gregkh] Cc: Jisheng Zhang Jisheng.Zhang@synaptics.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/dma-buf/sw_sync.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)

--- a/drivers/dma-buf/sw_sync.c +++ b/drivers/dma-buf/sw_sync.c @@ -321,8 +321,16 @@ static int sw_sync_debugfs_open(struct i static int sw_sync_debugfs_release(struct inode *inode, struct file *file) { struct sync_timeline *obj = file->private_data; + struct sync_pt *pt, *next;

- smp_wmb(); + spin_lock_irq(&obj->lock); + + list_for_each_entry_safe(pt, next, &obj->pt_list, link) { + fence_set_error(&pt->base, -ENOENT); + fence_signal_locked(&pt->base); + } + + spin_unlock_irq(&obj->lock);

sync_timeline_put(obj); return 0;

Patches currently in stable-queue which might be from dbehr@chromium.org are

queue-4.9/dma-buf-sw_sync-force-signal-all-unsignaled-fences-on-dying-timeline.patch