drm/i915: Grab dev->struct_mutex in i915_gem_pageflip_info
We could walk of a bad list otherwise when someone concurrently
unbinds stuff for fun.
I've suspected this as the root-cause behind seemingly inconsistent
state, but alas it's not.
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 8057fd4..76c2572 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -513,6 +513,11 @@
struct drm_device *dev = node->minor->dev;
unsigned long flags;
struct intel_crtc *crtc;
+ int ret;
+
+ ret = mutex_lock_interruptible(&dev->struct_mutex);
+ if (ret)
+ return ret;
for_each_intel_crtc(dev, crtc) {
const char pipe = pipe_name(crtc->pipe);
@@ -554,6 +559,8 @@
spin_unlock_irqrestore(&dev->event_lock, flags);
}
+ mutex_unlock(&dev->struct_mutex);
+
return 0;
}