Patch "dma-buf/sw_sync: force signal all unsignaled fences on dying timeline" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

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;a=summary

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@padovan.org
[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