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author | Thomas Hellstrom <thellstrom@vmware.com> | 2014-02-25 19:57:44 +0100 |
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committer | Thomas Hellstrom <thellstrom@vmware.com> | 2014-03-28 14:19:02 +0100 |
commit | c996fd0b956450563454e7ccc97a82ca31f9d043 (patch) | |
tree | 68fa27376f60773bd2feaf5340351cb29e0a834b /include/drm | |
parent | a12cd0025cdc0b4d43b79249dbd8c266af284032 (diff) | |
download | linux-stable-c996fd0b956450563454e7ccc97a82ca31f9d043.tar.gz linux-stable-c996fd0b956450563454e7ccc97a82ca31f9d043.tar.bz2 linux-stable-c996fd0b956450563454e7ccc97a82ca31f9d043.zip |
drm: Protect the master management with a drm_device::master_mutex v3
The master management was previously protected by the drm_device::struct_mutex.
In order to avoid locking order violations in a reworked dropped master
security check in the vmwgfx driver, break it out into a separate master_mutex.
Locking order is master_mutex -> struct_mutex.
Also remove drm_master::blocked since it's not used.
v2: Add an inline comment about what drm_device::master_mutex is protecting.
v3: Remove unneeded struct_mutex locks. Fix error returns in
drm_setmaster_ioctl().
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Diffstat (limited to 'include/drm')
-rw-r--r-- | include/drm/drmP.h | 46 |
1 files changed, 25 insertions, 21 deletions
diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 3d594ca7fa62..4e24a1a0daeb 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -405,7 +405,8 @@ struct drm_prime_file_private { struct drm_file { unsigned always_authenticated :1; unsigned authenticated :1; - unsigned is_master :1; /* this file private is a master for a minor */ + /* Whether we're master for a minor. Protected by master_mutex */ + unsigned is_master :1; /* true when the client has asked us to expose stereo 3D mode flags */ unsigned stereo_allowed :1; @@ -684,28 +685,29 @@ struct drm_gem_object { #include <drm/drm_crtc.h> -/* per-master structure */ +/** + * struct drm_master - drm master structure + * + * @refcount: Refcount for this master object. + * @minor: Link back to minor char device we are master for. Immutable. + * @unique: Unique identifier: e.g. busid. Protected by drm_global_mutex. + * @unique_len: Length of unique field. Protected by drm_global_mutex. + * @unique_size: Amount allocated. Protected by drm_global_mutex. + * @magiclist: Hash of used authentication tokens. Protected by struct_mutex. + * @magicfree: List of used authentication tokens. Protected by struct_mutex. + * @lock: DRI lock information. + * @driver_priv: Pointer to driver-private information. + */ struct drm_master { - - struct kref refcount; /* refcount for this master */ - - struct drm_minor *minor; /**< link back to minor we are a master for */ - - char *unique; /**< Unique identifier: e.g., busid */ - int unique_len; /**< Length of unique field */ - int unique_size; /**< amount allocated */ - - int blocked; /**< Blocked due to VC switch? */ - - /** \name Authentication */ - /*@{ */ + struct kref refcount; + struct drm_minor *minor; + char *unique; + int unique_len; + int unique_size; struct drm_open_hash magiclist; struct list_head magicfree; - /*@} */ - - struct drm_lock_data lock; /**< Information on hardware lock */ - - void *driver_priv; /**< Private structure for driver to use */ + struct drm_lock_data lock; + void *driver_priv; }; /* Size of ringbuffer for vblank timestamps. Just double-buffer @@ -1020,7 +1022,8 @@ struct drm_minor { struct list_head debugfs_list; struct mutex debugfs_lock; /* Protects debugfs_list. */ - struct drm_master *master; /* currently active master for this node */ + /* currently active master for this node. Protected by master_mutex */ + struct drm_master *master; struct drm_mode_group mode_group; }; @@ -1070,6 +1073,7 @@ struct drm_device { /*@{ */ spinlock_t count_lock; /**< For inuse, drm_device::open_count, drm_device::buf_use */ struct mutex struct_mutex; /**< For others */ + struct mutex master_mutex; /**< For drm_minor::master and drm_file::is_master */ /*@} */ /** \name Usage Counters */ |