diff options
Diffstat (limited to 'drivers/gpu/drm/drm_file.c')
| -rw-r--r-- | drivers/gpu/drm/drm_file.c | 40 |
1 files changed, 37 insertions, 3 deletions
diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c index 883d83bc0e3d..e692770ef6d3 100644 --- a/drivers/gpu/drm/drm_file.c +++ b/drivers/gpu/drm/drm_file.c @@ -160,7 +160,7 @@ struct drm_file *drm_file_alloc(struct drm_minor *minor) /* Get a unique identifier for fdinfo: */ file->client_id = atomic64_inc_return(&ident); - file->pid = get_pid(task_tgid(current)); + rcu_assign_pointer(file->pid, get_pid(task_tgid(current))); file->minor = minor; /* for compatibility root is always authenticated */ @@ -200,7 +200,7 @@ out_prime_destroy: drm_syncobj_release(file); if (drm_core_check_feature(dev, DRIVER_GEM)) drm_gem_release(dev, file); - put_pid(file->pid); + put_pid(rcu_access_pointer(file->pid)); kfree(file); return ERR_PTR(ret); @@ -291,7 +291,7 @@ void drm_file_free(struct drm_file *file) WARN_ON(!list_empty(&file->event_list)); - put_pid(file->pid); + put_pid(rcu_access_pointer(file->pid)); kfree(file); } @@ -505,6 +505,40 @@ int drm_release(struct inode *inode, struct file *filp) } EXPORT_SYMBOL(drm_release); +void drm_file_update_pid(struct drm_file *filp) +{ + struct drm_device *dev; + struct pid *pid, *old; + + /* + * Master nodes need to keep the original ownership in order for + * drm_master_check_perm to keep working correctly. (See comment in + * drm_auth.c.) + */ + if (filp->was_master) + return; + + pid = task_tgid(current); + + /* + * Quick unlocked check since the model is a single handover followed by + * exclusive repeated use. + */ + if (pid == rcu_access_pointer(filp->pid)) + return; + + dev = filp->minor->dev; + mutex_lock(&dev->filelist_mutex); + old = rcu_replace_pointer(filp->pid, pid, 1); + mutex_unlock(&dev->filelist_mutex); + + if (pid != old) { + get_pid(pid); + synchronize_rcu(); + put_pid(old); + } +} + /** * drm_release_noglobal - release method for DRM file * @inode: device inode |