drm: Protect master->unique with dev->master_mutex

No one looks at the major/minor versions except the unique/busid
stuff. If we protect that with the master_mutex (since it also affects
the unique of each master, oh well) we can mark these two IOCTL with
DRM_UNLOCKED.

While doing this I realized that the comment for the magic_map is
outdated, I've forgotten to update it in:

commit d2b34ee62b
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Jun 17 09:33:21 2016 +0200

    drm: Protect authmagic with master_mutex

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
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/20161210215255.7765-1-daniel.vetter@ffwll.ch
This commit is contained in:
Daniel Vetter 2016-12-10 22:52:52 +01:00
parent b9fb2a21ac
commit 5acc614ac4
2 changed files with 22 additions and 7 deletions

View File

@ -115,11 +115,15 @@ static int drm_getunique(struct drm_device *dev, void *data,
struct drm_unique *u = data;
struct drm_master *master = file_priv->master;
mutex_lock(&master->dev->master_mutex);
if (u->unique_len >= master->unique_len) {
if (copy_to_user(u->unique, master->unique, master->unique_len))
if (copy_to_user(u->unique, master->unique, master->unique_len)) {
mutex_unlock(&master->dev->master_mutex);
return -EFAULT;
}
}
u->unique_len = master->unique_len;
mutex_unlock(&master->dev->master_mutex);
return 0;
}
@ -340,6 +344,7 @@ static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *f
struct drm_set_version *sv = data;
int if_version, retcode = 0;
mutex_lock(&dev->master_mutex);
if (sv->drm_di_major != -1) {
if (sv->drm_di_major != DRM_IF_MAJOR ||
sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
@ -374,6 +379,7 @@ done:
sv->drm_di_minor = DRM_IF_MINOR;
sv->drm_dd_major = dev->driver->major;
sv->drm_dd_minor = dev->driver->minor;
mutex_unlock(&dev->master_mutex);
return retcode;
}
@ -528,7 +534,7 @@ EXPORT_SYMBOL(drm_ioctl_permit);
static const struct drm_ioctl_desc drm_ioctls[] = {
DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version,
DRM_UNLOCKED|DRM_RENDER_ALLOW|DRM_CONTROL_ALLOW),
DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),
DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, DRM_UNLOCKED),
DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, DRM_UNLOCKED),
DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),
DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, DRM_UNLOCKED),
@ -536,7 +542,7 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),
DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),
DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),
DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),
DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_UNLOCKED | DRM_MASTER),
DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),

View File

@ -33,10 +33,7 @@
*
* @refcount: Refcount for this master object.
* @dev: Link back to the DRM device
* @unique: Unique identifier: e.g. busid. Protected by drm_global_mutex.
* @unique_len: Length of unique field. Protected by drm_global_mutex.
* @magic_map: Map of used authentication tokens. Protected by struct_mutex.
* @lock: DRI lock information.
* @lock: DRI1 lock information.
* @driver_priv: Pointer to driver-private information.
*
* Note that master structures are only relevant for the legacy/primary device
@ -45,8 +42,20 @@
struct drm_master {
struct kref refcount;
struct drm_device *dev;
/**
* @unique: Unique identifier: e.g. busid. Protected by struct
* &drm_device master_mutex.
*/
char *unique;
/**
* @unique_len: Length of unique field. Protected by struct &drm_device
* master_mutex.
*/
int unique_len;
/**
* @magic_map: Map of used authentication tokens. Protected by struct
* &drm_device master_mutex.
*/
struct idr magic_map;
struct drm_lock_data lock;
void *driver_priv;