From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 8 Mar 2017 14:22:38 +0000 (+0000)
Subject: drm/i915: Check for an invalid seqno before __i915_gem_request_started
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=5b5554c51d38a227c4c5bee6e57026e4ebb0bde9;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

drm/i915: Check for an invalid seqno before __i915_gem_request_started

__i915_gem_request_started() asserts that the seqno is valid, but
i915_spin_request() was not checking before querying whether the request
had started.

Reported-by: Michał Winiarski <michal.winiarski@intel.com>
Fixes: 754c9fd57649 ("drm/i915: Protect the request->global_seqno with the engine->timeline lock")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170308142238.22994-1-chris@chris-wilson.co.uk
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---

diff --git a/drivers/gpu/drm/i915/i915_gem_request.h b/drivers/gpu/drm/i915/i915_gem_request.h
index 5018e55922f0..0cef887b0de4 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.h
+++ b/drivers/gpu/drm/i915/i915_gem_request.h
@@ -348,6 +348,9 @@ static inline bool i915_spin_request(const struct drm_i915_gem_request *request,
 	u32 seqno;
 
 	seqno = i915_gem_request_global_seqno(request);
+	if (!seqno)
+		return 0;
+
 	return (__i915_gem_request_started(request, seqno) &&
 		__i915_spin_request(request, seqno, state, timeout_us));
 }