[PATCH] drm/i915: Fix set_caching locking

[PATCH] drm/i915: Fix set_caching locking

[Ben Widawsky]

On the EINVAL case we don't release struct_mutex. It should be safe to
grab the lock after checking the parameters, which also resolves the
issues.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_gem.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 365a7dc..76bbb37 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3218,10 +3218,6 @@ int i915_gem_set_caching_ioctl(struct drm_device *dev, void *data,
 	enum i915_cache_level level;
 	int ret;
 
-	ret = i915_mutex_lock_interruptible(dev);
-	if (ret)
-		return ret;
-
 	switch (args->caching) {
 	case I915_CACHING_NONE:
 		level = I915_CACHE_NONE;
@@ -3233,6 +3229,10 @@ int i915_gem_set_caching_ioctl(struct drm_device *dev, void *data,
 		return -EINVAL;
 	}
 
+	ret = i915_mutex_lock_interruptible(dev);
+	if (ret)
+		return ret;
+
 	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
 	if (&obj->base == NULL) {
 		ret = -ENOENT;
-- 
1.7.12.1

Re: [PATCH] drm/i915: Fix set_caching locking

[Daniel Vetter]

On Wed, Sep 26, 2012 at 04:15:20PM -0700, Ben Widawsky wrote:
> On the EINVAL case we don't release struct_mutex. It should be safe to
> grab the lock after checking the parameters, which also resolves the
> issues.
> 
> Signed-off-by: Ben Widawsky <ben@bwidawsk.net>

Nice catch, thanks for the patch, applied to fixes.
-Daniel

> ---
>  drivers/gpu/drm/i915/i915_gem.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 365a7dc..76bbb37 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -3218,10 +3218,6 @@ int i915_gem_set_caching_ioctl(struct drm_device *dev, void *data,
>  	enum i915_cache_level level;
>  	int ret;
>  
> -	ret = i915_mutex_lock_interruptible(dev);
> -	if (ret)
> -		return ret;
> -
>  	switch (args->caching) {
>  	case I915_CACHING_NONE:
>  		level = I915_CACHE_NONE;
> @@ -3233,6 +3229,10 @@ int i915_gem_set_caching_ioctl(struct drm_device *dev, void *data,
>  		return -EINVAL;
>  	}
>  
> +	ret = i915_mutex_lock_interruptible(dev);
> +	if (ret)
> +		return ret;
> +
>  	obj = to_intel_bo(drm_gem_object_lookup(dev, file, args->handle));
>  	if (&obj->base == NULL) {
>  		ret = -ENOENT;
> -- 
> 1.7.12.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch