[PATCH 3/3] drm/xe: Warn on NULL job when user fence used in xe_sync_entry_signal

[Nirmoy Das <nirmoy.das@intel.com>]

Added a check and warn for NULL job when sync->type is
DRM_XE_SYNC_TYPE_USER_FENCE to prevent potential crashes
and aid in debugging

Cc: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
---
 drivers/gpu/drm/xe/xe_sync.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_sync.c b/drivers/gpu/drm/xe/xe_sync.c
index 02c9577fe418..fae466ba8e75 100644
--- a/drivers/gpu/drm/xe/xe_sync.c
+++ b/drivers/gpu/drm/xe/xe_sync.c
@@ -255,9 +255,13 @@ void xe_sync_entry_signal(struct xe_sync_entry *sync, struct xe_sched_job *job,
 			dma_fence_put(fence);
 		}
 	} else if (sync->type == DRM_XE_SYNC_TYPE_USER_FENCE) {
-		job->user_fence.used = true;
-		job->user_fence.addr = sync->addr;
-		job->user_fence.value = sync->timeline_value;
+		if (job) {
+			job->user_fence.used = true;
+			job->user_fence.addr = sync->addr;
+			job->user_fence.value = sync->timeline_value;
+		} else {
+			XE_WARN_ON("NULL job passed with DRM_XE_SYNC_TYPE_USER_FENCE");
+		}
 	}
 }
 
-- 
2.42.0