From d18d1a5ac811d12f7ebc1129230312b5f2c50cb8 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 31 Oct 2017 11:55:35 +0000 Subject: drm: Require __GFP_NOFAIL for the legacy drm_modeset_lock_all MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit To acquire all modeset locks requires a ww_ctx to be allocated. As this is the legacy path and the allocation small, to reduce the changes required (and complex untested error handling) to the legacy drivers, we simply assume that the allocation succeeds. At present, it relies on the too-small-to-fail rule, but syzbot found that by injecting a failure here we would hit the WARN. Document that this allocation must succeed with __GFP_NOFAIL. Signed-off-by: Chris Wilson Cc: Daniel Vetter Reported-by: syzbot Signed-off-by: Daniel Vetter Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20171031115535.15166-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/drm_modeset_lock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/gpu/drm/drm_modeset_lock.c') diff --git a/drivers/gpu/drm/drm_modeset_lock.c b/drivers/gpu/drm/drm_modeset_lock.c index e123497da0ca..963e23db0fe7 100644 --- a/drivers/gpu/drm/drm_modeset_lock.c +++ b/drivers/gpu/drm/drm_modeset_lock.c @@ -93,7 +93,7 @@ void drm_modeset_lock_all(struct drm_device *dev) struct drm_modeset_acquire_ctx *ctx; int ret; - ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL | __GFP_NOFAIL); if (WARN_ON(!ctx)) return; -- cgit