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drm: Protect authmagic with master_mutex

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Simplifies cleanup, and there's no reason drivers should ever care
about authmagic at all - it's all handled in the core.

And with that, Ladies and Gentlemen, it's time to pop the champagen
and celebrate: dev->struct_mutex is now officially gone from modern
drivers, and if a driver is using gem_free_object_unlocked and doesn't
do anything else silly it's positively impossible to ever touch
dev->struct_mutex at runtime, anywhere.

Well except for the mutex_init on driver load ;-)

v2: Rebased.

Cc: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466148814-8194-4-git-send-email-daniel.vetter@ffwll.ch
This commit is contained in:
Daniel Vetter
2016-06-17 09:33:21 +02:00
parent a77316bf24
commit d2b34ee62b
1 changed files with 6 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/gpu/drm/drm_auth.c
View File

@@ -49,7 +49,7 @@ int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv)
struct drm_auth *auth = data; struct drm_auth *auth = data;
int ret = 0; int ret = 0;
mutex_lock(&dev->struct_mutex); mutex_lock(&dev->master_mutex);
if (!file_priv->magic) { if (!file_priv->magic) {
ret = idr_alloc(&file_priv->master->magic_map, file_priv, ret = idr_alloc(&file_priv->master->magic_map, file_priv,
1, 0, GFP_KERNEL); 1, 0, GFP_KERNEL);
@@ -57,7 +57,7 @@ int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv)
file_priv->magic = ret; file_priv->magic = ret;
} }
auth->magic = file_priv->magic; auth->magic = file_priv->magic;
mutex_unlock(&dev->struct_mutex); mutex_unlock(&dev->master_mutex);
DRM_DEBUG("%u\n", auth->magic); DRM_DEBUG("%u\n", auth->magic);
@@ -82,13 +82,13 @@ int drm_authmagic(struct drm_device *dev, void *data,
DRM_DEBUG("%u\n", auth->magic); DRM_DEBUG("%u\n", auth->magic);
mutex_lock(&dev->struct_mutex); mutex_lock(&dev->master_mutex);
file = idr_find(&file_priv->master->magic_map, auth->magic); file = idr_find(&file_priv->master->magic_map, auth->magic);
if (file) { if (file) {
file->authenticated = 1; file->authenticated = 1;
idr_replace(&file_priv->master->magic_map, NULL, auth->magic); idr_replace(&file_priv->master->magic_map, NULL, auth->magic);
} }
mutex_unlock(&dev->struct_mutex); mutex_unlock(&dev->master_mutex);
return file ? 0 : -EINVAL; return file ? 0 : -EINVAL;
} }
@@ -117,7 +117,7 @@ static struct drm_master *drm_master_create(struct drm_device *dev)
* @dev: The associated device. * @dev: The associated device.
* @fpriv: File private identifying the client. * @fpriv: File private identifying the client.
* *
* This function must be called with dev::struct_mutex held. * This function must be called with dev::master_mutex held.
* Returns negative error code on failure. Zero on success. * Returns negative error code on failure. Zero on success.
*/ */
static int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv) static int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv)
@@ -248,12 +248,10 @@ void drm_master_release(struct drm_file *file_priv)
struct drm_device *dev = file_priv->minor->dev; struct drm_device *dev = file_priv->minor->dev;
struct drm_master *master = file_priv->master; struct drm_master *master = file_priv->master;
mutex_lock(&dev->struct_mutex); mutex_lock(&dev->master_mutex);
if (file_priv->magic) if (file_priv->magic)
idr_remove(&file_priv->master->magic_map, file_priv->magic); idr_remove(&file_priv->master->magic_map, file_priv->magic);
mutex_unlock(&dev->struct_mutex);
mutex_lock(&dev->master_mutex);
if (!file_priv->is_master) if (!file_priv->is_master)
goto out; goto out;