From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Christophe Leroy <christophe.leroy@c-s.fr>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] powerpc/futex: fix warning: 'oldval' may be used uninitialized in this function
Date: Thu, 22 Aug 2019 23:09:00 +1000 (AEST) [thread overview]
Message-ID: <46DlGj1KgTz9sPQ@ozlabs.org> (raw)
In-Reply-To: <86b72f0c134367b214910b27b9a6dd3321af93bb.1565774657.git.christophe.leroy@c-s.fr>
On Wed, 2019-08-14 at 09:25:52 UTC, Christophe Leroy wrote:
> CC kernel/futex.o
> kernel/futex.c: In function 'do_futex':
> kernel/futex.c:1676:17: warning: 'oldval' may be used uninitialized in this function [-Wmaybe-uninitialized]
> return oldval == cmparg;
> ^
> kernel/futex.c:1651:6: note: 'oldval' was declared here
> int oldval, ret;
> ^
>
> This is because arch_futex_atomic_op_inuser() only sets *oval
> if ret is NUL and GCC doesn't see that it will use it only when
> ret is NUL.
>
> Anyway, the non-NUL ret path is an error path that won't suffer from
> setting *oval, and as *oval is a local var in futex_atomic_op_inuser()
> it will have no impact.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/38a0d0cdb46d3f91534e5b9839ec2d67be14c59d
cheers
prev parent reply other threads:[~2019-08-22 13:41 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-14 9:25 [PATCH] powerpc/futex: fix warning: 'oldval' may be used uninitialized in this function Christophe Leroy
2019-08-16 12:35 ` Michael Ellerman
2019-08-22 13:09 ` Michael Ellerman [this message]
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