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From:   Bartosz Golaszewski <bgolaszewski@baylibre.com>
Date:   Wed, 24 Jun 2020 16:05:04 +0200
Message-ID: <CAMpxmJXajkf2F5KsWj2MpRsLjiuAdGT=XnLY_Ka3YN_WLsviiw@mail.gmail.com>
Subject: Re: [PATCH 10/22] gpiolib: cdev: fix minor race in GET_LINEINFO_WATCH
To:     Kent Gibson <warthog618@gmail.com>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        linux-gpio <linux-gpio@vger.kernel.org>,
        Linus Walleij <linus.walleij@linaro.org>
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wt., 23 cze 2020 o 06:02 Kent Gibson <warthog618@gmail.com> napisa=C5=82(a)=
:
>
> Merge separate usage of test_bit/set_bit into test_and_set_bit to remove
> the possibility of a race between the test and set.
>
> Similarly test_bit and clear_bit.
>
> In the existing code it is possible for two threads to race past the
> test_bit and then set or clear the watch bit, and neither return EBUSY.
>
> Signed-off-by: Kent Gibson <warthog618@gmail.com>
>

Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>