drm/i915: Avoid use-after-free of ctx in request tracepoints
trace_i915_gem_request_out may be used after the request is completed,
and so the request may have been retired on another thread, invalidating
the rq->ctx. Avoid dereferencing rq->ctx in the tracepoint by switching
to the fence context id instead, updating all tracepoints to match.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170316204235.27786-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
index 5503f5a..66404c5 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -590,7 +590,7 @@ TRACE_EVENT(i915_gem_request_queue,
TP_fast_assign(
__entry->dev = req->i915->drm.primary->index;
__entry->ring = req->engine->id;
- __entry->ctx = req->ctx->hw_id;
+ __entry->ctx = req->fence.context;
__entry->seqno = req->fence.seqno;
__entry->flags = flags;
),
@@ -637,8 +637,8 @@ DECLARE_EVENT_CLASS(i915_gem_request,
TP_fast_assign(
__entry->dev = req->i915->drm.primary->index;
- __entry->ctx = req->ctx->hw_id;
__entry->ring = req->engine->id;
+ __entry->ctx = req->fence.context;
__entry->seqno = req->fence.seqno;
__entry->global = req->global_seqno;
),
@@ -681,7 +681,7 @@ DECLARE_EVENT_CLASS(i915_gem_request_hw,
TP_fast_assign(
__entry->dev = req->i915->drm.primary->index;
__entry->ring = req->engine->id;
- __entry->ctx = req->ctx->hw_id;
+ __entry->ctx = req->fence.context;
__entry->seqno = req->fence.seqno;
__entry->global_seqno = req->global_seqno;
__entry->port = port;
@@ -776,7 +776,7 @@ TRACE_EVENT(i915_gem_request_wait_begin,
TP_fast_assign(
__entry->dev = req->i915->drm.primary->index;
__entry->ring = req->engine->id;
- __entry->ctx = req->ctx->hw_id;
+ __entry->ctx = req->fence.context;
__entry->seqno = req->fence.seqno;
__entry->global = req->global_seqno;
__entry->flags = flags;