From bdbbf7d619d1fd2f1fa9eb529b7817e4faf73f5e Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 22 Jun 2017 11:47:22 +0100
Subject: [PATCH] drm/i915: Clear execbuf's vma backpointer upon release
Git-commit: bdbbf7d619d1fd2f1fa9eb529b7817e4faf73f5e
Patch-mainline: v4.13-rc1
References: FATE#322643 bsc#1055900
No-fix: 51d05e1b29676a0425749a1533b87e3ad3c6f176

commit 2889caa92321 ("drm/i915: Eliminate lots of iterations over the
execobjects array") jiggled around the error handling and replace a test
that we cleaned up properly after ourselves with an assertion. That
assertion failed because in the release function (moments after the
assertion) we were indeed forgetting to mark the vma as cleared. The
consequence was when testing an invalid relocation address, we would try
to release the vma twice (following the couple of attempts to verify the
address) and on the second release notice that the first release was
incomplete.

Testcase: igt/gem_reloc_overflow/invalid-address
Fixes: 2889caa92321 ("drm/i915: Eliminate lots of iterations over the execobjects array")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170622104722.2583-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
(cherry picked from commit 51d05e1b29676a0425749a1533b87e3ad3c6f176)

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -878,6 +878,7 @@ static void eb_release_vmas(const struct
 
 		GEM_BUG_ON(vma->exec_entry != entry);
 		vma->exec_entry = NULL;
+		__exec_to_vma(entry) = 0;
 
 		if (entry->flags & __EXEC_OBJECT_HAS_PIN)
 			__eb_unreserve_vma(vma, entry);