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drm: fix drm_mode_getconnector() locking imbalance regression

PATCH Applied Tommi Rantala 3 participants 3 messages Apr 3, 2015 – Apr 7, 2015

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Tommi Rantala

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#0 lore raw

PATCH 1/1 drm: fix drm_mode_getconnector() locking imbalance regression

Regression in commit 2caa80e72b57c6216aec6f6a11fcfb4fec46daa0

Author: Daniel Vetter <[email protected]>
Date:   Sun Feb 22 11:38:36 2015 +0100

drm: Fix deadlock due to getconnector locking changes

If the drm_connector_find() call returns NULL, we should no longer call drm_modeset_unlock() to avoid locking imbalance.

Signed-off-by Tommi Rantala <[email protected]>
Cc Daniel Vetter <[email protected]>
---
 drivers/gpu/drm/drm_crtc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
drivers/gpu/drm/drm_crtc.c +3 -1
index 679b10e..b6f076b 100644
@@ -2121,7 +2121,7 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
 	connector = drm_connector_find(dev, out_resp->connector_id);
 	if (!connector) {
 		ret = -ENOENT;
-		goto out;
+		goto out_unlock;
 	}
 
 	for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++)

@@ -2201,6 +2201,8 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
 
 out:
 	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
+out_unlock:
 	mutex_unlock(&dev->mode_config.mutex);
 
 	return ret;
Signature · 6 lines
2.1.0

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Reviewed-by on v1 1/1
#1 lore raw
Quoted 11 lines · Tommi Rantala

Regression in commit 2caa80e72b57c6216aec6f6a11fcfb4fec46daa0

Author: Daniel Vetter <[email protected]>
Date:   Sun Feb 22 11:38:36 2015 +0100

drm: Fix deadlock due to getconnector locking changes

If the drm_connector_find() call returns NULL, we should no longer call drm_modeset_unlock() to avoid locking imbalance.

Signed-off-by Tommi Rantala <[email protected]>
Cc Daniel Vetter <[email protected]>

Oops, thanks for catching this. If this missed 4.0 then we need to backport it.

Reviewed-by Daniel Vetter <[email protected]>
Quoted 29 lines
---
 drivers/gpu/drm/drm_crtc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
drivers/gpu/drm/drm_crtc.c +3 -1
index 679b10e..b6f076b 100644
@@ -2121,7 +2121,7 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
 	connector = drm_connector_find(dev, out_resp->connector_id);
 	if (!connector) {
 		ret = -ENOENT;
-		goto out;
+		goto out_unlock;
 	}
 
 	for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++)

@@ -2201,6 +2201,8 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
 
 out:
 	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
+out_unlock:
 	mutex_unlock(&dev->mode_config.mutex);
 
 	return ret;
Signature · 1 line
2.1.0
Signature · 7 lines
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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Applied
#2 lore raw
Quoted 10 lines · Daniel Vetter
Quoted 9 lines · Tommi Rantala

Regression in commit 2caa80e72b57c6216aec6f6a11fcfb4fec46daa0

Author: Daniel Vetter <[email protected]>
Date:   Sun Feb 22 11:38:36 2015 +0100

drm: Fix deadlock due to getconnector locking changes

If the drm_connector_find() call returns NULL, we should no longer call drm_modeset_unlock() to avoid locking imbalance.

Quoted 7 lines
Quoted 2 lines
Signed-off-by Tommi Rantala <[email protected]>
Cc Daniel Vetter <[email protected]>

Oops, thanks for catching this. If this missed 4.0 then we need to backport it.

Reviewed-by Daniel Vetter <[email protected]>

Pushed to topic/drm-fixes, should still make it to 4.0. Thanks for the patch and review.

BR,
Jani.

Quoted 39 lines
Quoted 30 lines
---
 drivers/gpu/drm/drm_crtc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
drivers/gpu/drm/drm_crtc.c +3 -1
index 679b10e..b6f076b 100644
@@ -2121,7 +2121,7 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
 	connector = drm_connector_find(dev, out_resp->connector_id);
 	if (!connector) {
 		ret = -ENOENT;
-		goto out;
+		goto out_unlock;
 	}
 
 	for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++)

@@ -2201,6 +2201,8 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
 
 out:
 	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
+out_unlock:
 	mutex_unlock(&dev->mode_config.mutex);
 
 	return ret;
Signature · 1 line
2.1.0
Signature · 7 lines
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
[email protected]
http://lists.freedesktop.org/mailman/listinfo/dri-devel
Signature · 5 lines
Jani Nikula, Intel Open Source Technology Center
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