On Thu, Sep 05, 2019 at 11:07:14AM +0800, Baolin Wang wrote: > From: Waiman Long <longman@xxxxxxxxxx> > > [Upstream commit 513e1073d52e55b8024b4f238a48de7587c64ccf] > > Tetsuo Handa had reported he saw an incorrect "downgrading a read lock" > warning right after a previous lockdep warning. It is likely that the > previous warning turned off lock debugging causing the lockdep to have > inconsistency states leading to the lock downgrade warning. > > Fix that by add a check for debug_locks at the beginning of > __lock_downgrade(). > > Reported-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > Reported-by: syzbot+53383ae265fb161ef488@xxxxxxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Waiman Long <longman@xxxxxxxxxx> > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Will Deacon <will.deacon@xxxxxxx> > Link: https://lkml.kernel.org/r/1547093005-26085-1-git-send-email-longman@xxxxxxxxxx > Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> > Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx> > --- > kernel/locking/lockdep.c | 3 +++ > 1 file changed, 3 insertions(+) Why isn't this relevant for 4.19.y? I can't add a patch to 4.14.y and then have someone upgrade to 4.19.y and not have the same fix in there, that would be a regression. So can you redo this series also with a 4.19.y set at the same so we don't get out of sync? I've queued up your first patch already as that was in 4.19.y (and also needed in 4.9.y). thanks, greg k-h
