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Add it. Mhm, lockdep should be able to deduce that when there might be faults under the dma_resv lock there might also be faults under the drm_modeset_lock. > > Motivated by a syzbot report that blew up on bcachefs doing an > unconditional console_lock way deep in the locking hierarchy, and > lockdep only noticing the depency loop in a drm ioctl instead of much > earlier. This annotation will make sure such issues have a much harder > time escaping. > > References: https://lore.kernel.org/dri-devel/00000000000073db8b061cd43496@google.com/ > Signed-off-by: Daniel Vetter > Cc: Maarten Lankhorst > Cc: Maxime Ripard > Cc: Thomas Zimmermann > Cc: Sumit Semwal > Cc: "Christian König" > Cc: linux-media@vger.kernel.org > Cc: linaro-mm-sig@lists.linaro.org On the other hand pointing it out explicitly doesn't hurts us at all, so Reviewed-by: Christian König . Regards, Christian. > --- > drivers/gpu/drm/drm_mode_config.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c > index 568972258222..37d2e0a4ef4b 100644 > --- a/drivers/gpu/drm/drm_mode_config.c > +++ b/drivers/gpu/drm/drm_mode_config.c > @@ -456,6 +456,8 @@ int drmm_mode_config_init(struct drm_device *dev) > if (ret == -EDEADLK) > ret = drm_modeset_backoff(&modeset_ctx); > > + might_fault(); > + > ww_acquire_init(&resv_ctx, &reservation_ww_class); > ret = dma_resv_lock(&resv, &resv_ctx); > if (ret == -EDEADLK)