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From:   Xiaoming Ni <nixiaoming@huawei.com>
To:     <linux-kernel@vger.kernel.org>, <stable@vger.kernel.org>,
        <gregkh@linuxfoundation.org>, <sashal@kernel.org>,
        <tglx@linutronix.de>
CC:     <nixiaoming@huawei.com>, <wangle6@huawei.com>,
        <zhengyejian1@huawei.com>
Subject: [PATCH stable-rc queue/4.9 0/1] repatch 
Date:   Mon, 22 Feb 2021 15:03:27 +0800
Message-ID: <20210222070328.102384-1-nixiaoming@huawei.com>
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I found a dead code in the queue/4.9 branch of the stable-rc repository.

2021-02-03:
commit c27f392040e2f6 ("futex: Provide distinct return value when
 owner is exiting")
	The function handle_exit_race does not exist. Therefore, the
	change in handle_exit_race() is ignored in the patch round.

2021-02-22:
commit e55cb811e612 ("futex: Cure exit race")
	Define the handle_exit_race() function,
	but no branch in the function returns EBUSY.
	As a result, dead code occurs in the attach_to_pi_owner():

		int ret = handle_exit_race(uaddr, uval, p);
		...
		if (ret == -EBUSY)
			*exiting = p; /* dead code */

To fix the dead code, modify the commit e55cb811e612 ("futex: Cure exit race"), 
or install a patch to incorporate the changes in handle_exit_race().

I am unfamiliar with the processing of the stable-rc queue branch,
and I cannot find the patch mail of the current branch in
	https://lore.kernel.org/lkml/?q=%22futex%3A+Cure+exit+race%22
Therefore, I re-integrated commit ac31c7ff8624 ("futex: Provide distinct
 return value when owner is exiting").

-----

Thomas Gleixner (1):
  futex: Provide distinct return value when owner is exiting

 kernel/futex.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

-- 
2.27.0