From: Andrey Konovalov <andreyknvl@google.com>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Johan Hovold <johan@kernel.org>,
"Gustavo A . R . Silva" <garsilva@embeddedor.com>,
Arvind Yadav <arvind.yadav.cs@gmail.com>,
USB list <linux-usb@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Kostya Serebryany <kcc@google.com>
Subject: Re: [PATCH v2] uwb: properly check kthread_run return value
Date: Thu, 14 Sep 2017 14:31:25 +0200 [thread overview]
Message-ID: <CAAeHK+xN+xFxjR+c6RRAau1h2jpouCsu6nbr4S0Rf_sYDhJg=g@mail.gmail.com> (raw)
In-Reply-To: <CACT4Y+YC-6L8XPXTpdRYccap+nS-oRvcV+fc13+X_Q8Q1Lgfzw@mail.gmail.com>
On Wed, Sep 13, 2017 at 6:53 PM, Dmitry Vyukov <dvyukov@google.com> wrote:
> On Wed, Sep 13, 2017 at 6:06 PM, Andrey Konovalov <andreyknvl@google.com> wrote:
>> uwbd_start() calls kthread_run() and checks that the return value is
>> not NULL. But the return value is not NULL in case kthread_run() fails,
>> it takes the form of ERR_PTR(-EINTR).
>>
>> Use IS_ERR() instead.
>>
>> Also add a check to uwbd_stop().
>>
>> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
>> ---
>> drivers/uwb/uwbd.c | 5 +++--
>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/uwb/uwbd.c b/drivers/uwb/uwbd.c
>> index 01c20a260a8b..2a3cc48d837c 100644
>> --- a/drivers/uwb/uwbd.c
>> +++ b/drivers/uwb/uwbd.c
>> @@ -303,7 +303,7 @@ static int uwbd(void *param)
>> void uwbd_start(struct uwb_rc *rc)
>> {
>> rc->uwbd.task = kthread_run(uwbd, rc, "uwbd");
>> - if (rc->uwbd.task == NULL)
>> + if (IS_ERR(rc->uwbd.task))
>> printk(KERN_ERR "UWB: Cannot start management daemon; "
>> "UWB won't work\n");
>> else
>> @@ -313,7 +313,8 @@ void uwbd_start(struct uwb_rc *rc)
>> /* Stop the UWB daemon and free any unprocessed events */
>> void uwbd_stop(struct uwb_rc *rc)
>> {
>> - kthread_stop(rc->uwbd.task);
>> + if (!IS_ERR(rc->uwbd.task))
>> + kthread_stop(rc->uwbd.task);
>
> It looks weird to assign an error to rc->uwbd.task and leave it there.
> I think it's better to not assign errors to rc->uwbd.task, i.e. it's
> either a valid task or NULL.
Sent v3.
>
>> uwbd_flush(rc);
>> }
>>
>> --
>> 2.14.1.581.gf28d330327-goog
>>
prev parent reply other threads:[~2017-09-14 12:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-13 16:06 [PATCH v2] uwb: properly check kthread_run return value Andrey Konovalov
2017-09-13 16:53 ` Dmitry Vyukov
2017-09-14 12:31 ` Andrey Konovalov [this message]
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