Re: [tip:core/urgent] futex: Address compiler warnings in exit_robust_list

From: Darren Hart
Date: Wed Nov 10 2010 - 15:21:30 EST


2010/11/10 Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>:
> Hallo Thomas,
>
> On Wed, Nov 10, 2010 at 12:30:44PM +0000, tip-bot for Darren Hart wrote:
>> Commit-ID:  4c115e951d80aff126468adaec7a6c7854f61ab8
>> Gitweb:     http://git.kernel.org/tip/4c115e951d80aff126468adaec7a6c7854f61ab8
>> Author:     Darren Hart <dvhart@xxxxxxxxxxxxxxx>
>> AuthorDate: Thu, 4 Nov 2010 15:00:00 -0400
>> Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>> CommitDate: Wed, 10 Nov 2010 13:27:50 +0100
>>
>> futex: Address compiler warnings in exit_robust_list
>>
>> Since commit 1dcc41bb (futex: Change 3rd arg of fetch_robust_entry()
>> to unsigned int*) some gcc versions decided to emit the following
>> warning:
>>
>> kernel/futex.c: In function ‘exit_robust_list’:
>> kernel/futex.c:2492: warning: ‘next_pi’ may be used uninitialized in this function
>>
>> The commit did not introduce the warning as gcc should have warned
>> before that commit as well. It's just gcc being silly.
>>
>> The code path really can't result in next_pi being unitialized (or
>> should not), but let's keep the build clean. Annotate next_pi as an
>> uninitialized_var.
>>
>> [ tglx: Addressed the same issue in futex_compat.c and massaged the
>>       changelog ]
>>
>> Signed-off-by: Darren Hart <dvhart@xxxxxxxxxxxxxxx>
>> Tested-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxx>
>> Tested-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> I don't care much (at least until someone claims this change to
> introduce a regression), but I didn't test it.  I only suggested to use
> uninitialized_var instead of = 0.
>

Uwe, I added you after you said I could add the ARM platform and
compiler to the list. I took that to mean you had confirmed that the
patch fixed the warning on that platform. I apologize as this is
apparently not the case.

--
Darren
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