From: Eric Anholt <eric@anholt.net>
Date: Wed, 25 Feb 2009 06:14:12 +0000 (-0800)
Subject: drm/i915: Fix use-before-null-check in i915_irq_emit().
X-Git-Tag: 2.1b_release~13887^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=299eb93c5f651b2bc368ada67d8471e4c575fa21;p=platform%2Fkernel%2Fkernel-mfld-blackbay.git

drm/i915: Fix use-before-null-check in i915_irq_emit().

This could be triggered by a client asking to emit an irq when the device
wasn't initialized.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>
---

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 548ff2c..87b6b60 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -383,12 +383,13 @@ int i915_irq_emit(struct drm_device *dev, void *data,
 	drm_i915_irq_emit_t *emit = data;
 	int result;
 
-	RING_LOCK_TEST_WITH_RETURN(dev, file_priv);
-
 	if (!dev_priv) {
 		DRM_ERROR("called with no initialization\n");
 		return -EINVAL;
 	}
+
+	RING_LOCK_TEST_WITH_RETURN(dev, file_priv);
+
 	mutex_lock(&dev->struct_mutex);
 	result = i915_emit_irq(dev);
 	mutex_unlock(&dev->struct_mutex);