31 Oct
2017
31 Oct
'17
1:12 p.m.
Quoting Chris Wilson (2017-10-31 11:55:35)
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.
Reported-by: syzbot (syzkaller)
Proper credit is Reported-by: syzbot syzkaller@googlegroups.com
Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Daniel Vetter daniel.vetter@ffwll.ch