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From: Greg KH <greg@kroah.com>
To: Baolin Wang <baolin.wang@linaro.org>
Cc: stable@vger.kernel.org, peterz@infradead.org, mingo@redhat.com,
	longman@redhat.com, arnd@arndb.de, orsonzhai@gmail.com,
	vincent.guittot@linaro.org, linux-kernel@vger.kernel.org
Subject: Re: [BACKPORT 4.14.y v2 2/6] locking/lockdep: Add debug_locks check in __lock_downgrade()
Date: Tue, 10 Sep 2019 15:32:42 +0100	[thread overview]
Message-ID: <20190910143242.GB3362@kroah.com> (raw)
In-Reply-To: <7d3d221015cd343df47de4a68ed4776aca2ca0ab.1567649729.git.baolin.wang@linaro.org>

On Thu, Sep 05, 2019 at 11:07:14AM +0800, Baolin Wang wrote:
> From: Waiman Long <longman@redhat.com>
> 
> [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@i-love.sakura.ne.jp>
> Reported-by: syzbot+53383ae265fb161ef488@syzkaller.appspotmail.com
> Signed-off-by: Waiman Long <longman@redhat.com>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Will Deacon <will.deacon@arm.com>
> Link: https://lkml.kernel.org/r/1547093005-26085-1-git-send-email-longman@redhat.com
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
> ---
>  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

  reply	other threads:[~2019-09-10 14:32 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-05  3:05 [BACKPORT 4.14.y v2 0/6] Candidates from Spreadtrum 4.14 product kernel Baolin Wang
2019-09-05  3:06 ` [BACKPORT 4.14.y v2 1/6] ip6: fix skb leak in ip6frag_expire_frag_queue() Baolin Wang
2019-09-05  3:07 ` [BACKPORT 4.14.y v2 2/6] locking/lockdep: Add debug_locks check in __lock_downgrade() Baolin Wang
2019-09-10 14:32   ` Greg KH [this message]
2019-09-11  3:39     ` Baolin Wang
2019-09-05  3:07 ` [BACKPORT 4.14.y v2 3/6] pinctrl: sprd: Use define directive for sprd_pinconf_params values Baolin Wang
2019-09-05  3:08 ` [BACKPORT 4.14.y v2 4/6] power: supply: sysfs: ratelimit property read error message Baolin Wang
2019-09-05  3:10 ` [BACKPORT 4.14.y v2 5/6] ppp: mppe: Revert "ppp: mppe: Add softdep to arc4" Baolin Wang
2019-09-05 16:16   ` Eric Biggers
2019-09-06  6:13     ` Baolin Wang
2019-09-05  3:11 ` [BACKPORT 4.14.y v2 6/6] serial: sprd: Modify the baud rate calculation formula Baolin Wang
2019-09-05  9:01   ` Johan Hovold
2019-09-05  9:58     ` Baolin Wang
2019-09-20  8:06       ` Johan Hovold

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