From: Thomas Zimmermann Date: Thu, 9 Oct 2025 13:16:29 +0000 (+0200) Subject: drm/log: Do not hold lock across drm_client_release() X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=33ba21e9e1baac2c1b2d4a01d7529daf1c7ce344;p=thirdparty%2Fkernel%2Flinux.git drm/log: Do not hold lock across drm_client_release() When calling drm_client_release(), the client is already quiescent. Internal locks should therefore be dropped before the caller releases the client. In the case of the DRM log, concurrency originates from the console or from client events. The console has been unregistered in the previous line. The caller of the unregister callback, drm_log_client_unregister(), holds clientlist_mutex from struct drm_device to protect against concurrent client events. It is therefore safe to release the client without holding locks. Signed-off-by: Thomas Zimmermann Reviewed-by: Jocelyn Falempe > Link: https://lore.kernel.org/r/20251009132006.45834-3-tzimmermann@suse.de --- diff --git a/drivers/gpu/drm/clients/drm_log.c b/drivers/gpu/drm/clients/drm_log.c index fd8556dd58ed8..d040be2e9d7a0 100644 --- a/drivers/gpu/drm/clients/drm_log.c +++ b/drivers/gpu/drm/clients/drm_log.c @@ -302,8 +302,8 @@ static void drm_log_client_unregister(struct drm_client_dev *client) mutex_lock(&dlog->lock); drm_log_free_scanout(client); - drm_client_release(client); mutex_unlock(&dlog->lock); + drm_client_release(client); kfree(dlog); drm_dbg(dev, "Unregistered with drm log\n"); }