[PATCH 4.14 11/45] drm/syncobj: Dont leak fences when WAIT_FOR_SUBMIT is set

From: Greg Kroah-Hartman
Date: Thu Oct 11 2018 - 11:45:10 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jason Ekstrand <jason@xxxxxxxxxxxxxx>

commit 337fe9f5c1e7de1f391c6a692531379d2aa2ee11 upstream.

We attempt to get fences earlier in the hopes that everything will
already have fences and no callbacks will be needed. If we do succeed
in getting a fence, getting one a second time will result in a duplicate
ref with no unref. This is causing memory leaks in Vulkan applications
that create a lot of fences; playing for a few hours can, apparently,
bring down the system.

Cc: stable@xxxxxxxxxxxxxxx
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107899
Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jason Ekstrand <jason@xxxxxxxxxxxxxx>
Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20180926071703.15257-1-jason.ekstrand@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gpu/drm/drm_syncobj.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -96,6 +96,8 @@ static int drm_syncobj_fence_get_or_add_
{
int ret;

+ WARN_ON(*fence);
+
*fence = drm_syncobj_fence_get(syncobj);
if (*fence)
return 1;
@@ -656,6 +658,9 @@ static signed long drm_syncobj_array_wai

if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
for (i = 0; i < count; ++i) {
+ if (entries[i].fence)
+ continue;
+
drm_syncobj_fence_get_or_add_callback(syncobjs[i],
&entries[i].fence,
&entries[i].syncobj_cb,