drm/radeon: fix oops in ttm reserve when pageflipping (v2)
We need to take a reference to this object, pinning doesn't take a reference
so if userspace deletes the object it can disappear even if pinned.
v2: fix error paths to unreference properly also.
should fix:
https://bugzilla.kernel.org/show_bug.cgi?id=32402
and
https://bugzilla.redhat.com/show_bug.cgi?id=680651
Acked-By: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index ae247ee..292f73f 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -264,6 +264,8 @@
radeon_bo_unreserve(work->old_rbo);
} else
DRM_ERROR("failed to reserve buffer after flip\n");
+
+ drm_gem_object_unreference_unlocked(&work->old_rbo->gem_base);
kfree(work);
}
@@ -371,6 +373,8 @@
new_radeon_fb = to_radeon_framebuffer(fb);
/* schedule unpin of the old buffer */
obj = old_radeon_fb->obj;
+ /* take a reference to the old object */
+ drm_gem_object_reference(obj);
rbo = gem_to_radeon_bo(obj);
work->old_rbo = rbo;
INIT_WORK(&work->work, radeon_unpin_work_func);
@@ -378,12 +382,9 @@
/* We borrow the event spin lock for protecting unpin_work */
spin_lock_irqsave(&dev->event_lock, flags);
if (radeon_crtc->unpin_work) {
- spin_unlock_irqrestore(&dev->event_lock, flags);
- kfree(work);
- radeon_fence_unref(&fence);
-
DRM_DEBUG_DRIVER("flip queue: crtc already busy\n");
- return -EBUSY;
+ r = -EBUSY;
+ goto unlock_free;
}
radeon_crtc->unpin_work = work;
radeon_crtc->deferred_flip_completion = 0;
@@ -497,6 +498,8 @@
pflip_cleanup:
spin_lock_irqsave(&dev->event_lock, flags);
radeon_crtc->unpin_work = NULL;
+unlock_free:
+ drm_gem_object_unreference_unlocked(old_radeon_fb->obj);
spin_unlock_irqrestore(&dev->event_lock, flags);
radeon_fence_unref(&fence);
kfree(work);