drm/i915: Don't destroy the vma placeholder during execbuffer reservation
The execbuffer handle and exec_link were moved from the object into the
vma. As the vma may be unbound and destroyed whilst attempting to
reserve the execbuffer objects (either through a forced unbind to fix up
a misalignment or through an evict-everything call) we need to prevent
the free of the i915_vma itself. Otherwise not only is the list of
objects to reserve corrupt, but we continue to reference stale vma
entries.
Fixes kernel crash with i-g-t/gem_evict_everything
This regression has been introduced in
commit 04038a515d6eda6dd0857c0ade0b3950d372f4c0
Author: Ben Widawsky <ben@bwidawsk.net>
AuthorDate: Wed Aug 14 11:38:36 2013 +0200
drm/i915: Convert execbuf code to use vmas
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
References: http://www.spinics.net/lists/intel-gfx/msg32038.html
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=68298
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 6820d0a..29b7e1c 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4159,6 +4159,11 @@
{
WARN_ON(vma->node.allocated);
list_del(&vma->vma_link);
+
+ /* Keep the vma as a placeholder in the execbuffer reservation lists */
+ if (!list_empty(&vma->exec_list))
+ return;
+
kfree(vma);
}