From 9272f73f79bd780502134f227fa52fd280ecda17 Mon Sep 17 00:00:00 2001 From: Chuanxiao Dong Date: Fri, 17 Feb 2017 19:29:52 +0800 Subject: [PATCH] drm/i915/gvt: add a NULL pointer check to avoid kernel panic Due to the request replay, context switch interrupt may come after gvt free the workload thus can cause a kernel NULL pointer kernel panic. This patch will add a simple check to avoid this for a short term. From long term, gvt workload lifecycle doesn't match with i915 request and need to find a proper way to manage this. v4: simplify the NULL pointer check. v5: add unlikely to optimize. Signed-off-by: Chuanxiao Dong Signed-off-by: Zhenyu Wang --- drivers/gpu/drm/i915/gvt/scheduler.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c index d6b6d0efdd1a..e355a82ccabd 100644 --- a/drivers/gpu/drm/i915/gvt/scheduler.c +++ b/drivers/gpu/drm/i915/gvt/scheduler.c @@ -139,6 +139,9 @@ static int shadow_context_status_change(struct notifier_block *nb, struct intel_vgpu_workload *workload = scheduler->current_workload[req->engine->id]; + if (unlikely(!workload)) + return NOTIFY_OK; + switch (action) { case INTEL_CONTEXT_SCHEDULE_IN: intel_gvt_load_render_mmio(workload->vgpu, -- 2.20.1