From: Segher Boessenkool <segher@kernel.crashing.org>
To: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: linux-kernel@vger.kernel.org, Paul Mackerras <paulus@samba.org>,
linuxppc-dev@lists.ozlabs.org
Subject: Re: GCC bug ? Re: [PATCH v2 10/10] powerpc/32s: Implement Kernel Userspace Access Protection
Date: Wed, 22 Jan 2020 07:18:54 -0600 [thread overview]
Message-ID: <20200122131854.GK3191@gate.crashing.org> (raw)
In-Reply-To: <8501a33e-6c76-b6bd-9d8e-985313f94579@c-s.fr>
Hi!
On Wed, Jan 22, 2020 at 07:57:15AM +0100, Christophe Leroy wrote:
> GCC doc also says:
>
> "if you use it in an inlined function and pass an argument of the
> function as the argument to the built-in, GCC never returns 1 when you
> call the inline function with a string constant"
>
> Does GCC considers (void*)0 as a string constant ?
No, because it isn't (it's a pointer, not an array of characters).
Segher
WARNING: multiple messages have this Message-ID (diff)
From: Segher Boessenkool <segher@kernel.crashing.org>
To: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
ruscur@russell.cc, linux-kernel@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org
Subject: Re: GCC bug ? Re: [PATCH v2 10/10] powerpc/32s: Implement Kernel Userspace Access Protection
Date: Wed, 22 Jan 2020 07:18:54 -0600 [thread overview]
Message-ID: <20200122131854.GK3191@gate.crashing.org> (raw)
In-Reply-To: <8501a33e-6c76-b6bd-9d8e-985313f94579@c-s.fr>
Hi!
On Wed, Jan 22, 2020 at 07:57:15AM +0100, Christophe Leroy wrote:
> GCC doc also says:
>
> "if you use it in an inlined function and pass an argument of the
> function as the argument to the built-in, GCC never returns 1 when you
> call the inline function with a string constant"
>
> Does GCC considers (void*)0 as a string constant ?
No, because it isn't (it's a pointer, not an array of characters).
Segher
next prev parent reply other threads:[~2020-01-22 13:24 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-11 8:30 [PATCH v2 00/10] Kernel Userspace protection for PPC32 Christophe Leroy
2019-03-11 8:30 ` Christophe Leroy
2019-03-11 8:30 ` [PATCH v2 01/10] powerpc/6xx: fix setup and use of SPRN_SPRG_PGDIR for hash32 Christophe Leroy
2019-03-11 8:30 ` Christophe Leroy
2019-03-20 13:04 ` [v2, " Michael Ellerman
2019-03-11 8:30 ` [PATCH v2 02/10] powerpc/mm: Detect bad KUAP faults (Squash of v5 series) Christophe Leroy
2019-03-11 8:30 ` Christophe Leroy
2019-03-11 8:30 ` [PATCH v2 03/10] powerpc/32: Remove MSR_PR test when returning from syscall Christophe Leroy
2019-03-11 8:30 ` Christophe Leroy
2019-04-21 14:18 ` [v2, " Michael Ellerman
2019-03-11 8:30 ` [PATCH v2 04/10] powerpc/32: Prepare for Kernel Userspace Access Protection Christophe Leroy
2019-03-11 8:30 ` Christophe Leroy
2019-03-11 8:30 ` [PATCH v2 05/10] powerpc/8xx: Only define APG0 and APG1 Christophe Leroy
2019-03-11 8:30 ` Christophe Leroy
2019-03-11 8:30 ` [PATCH v2 06/10] powerpc/8xx: Add Kernel Userspace Execution Prevention Christophe Leroy
2019-03-11 8:30 ` Christophe Leroy
2019-03-11 8:30 ` [PATCH v2 07/10] powerpc/8xx: Add Kernel Userspace Access Protection Christophe Leroy
2019-03-11 8:30 ` Christophe Leroy
2019-04-18 6:53 ` Michael Ellerman
2019-04-18 6:53 ` Michael Ellerman
2019-03-11 8:30 ` [PATCH v2 08/10] powerpc/32s: Implement Kernel Userspace Execution Prevention Christophe Leroy
2019-03-11 8:30 ` Christophe Leroy
2019-03-11 8:30 ` [PATCH v2 09/10] powerpc/32s: Prepare Kernel Userspace Access Protection Christophe Leroy
2019-03-11 8:30 ` Christophe Leroy
2019-03-11 8:30 ` [PATCH v2 10/10] powerpc/32s: Implement " Christophe Leroy
2019-03-11 8:30 ` Christophe Leroy
2019-04-18 6:55 ` Michael Ellerman
2019-04-18 6:55 ` Michael Ellerman
2019-04-23 9:26 ` Christophe Leroy
2019-04-23 9:26 ` Christophe Leroy
2020-01-21 17:22 ` GCC bug ? " Christophe Leroy
2020-01-21 17:22 ` Christophe Leroy
2020-01-21 19:55 ` Segher Boessenkool
2020-01-21 19:55 ` Segher Boessenkool
2020-01-22 6:52 ` Christophe Leroy
2020-01-22 6:52 ` Christophe Leroy
2020-01-22 13:36 ` Segher Boessenkool
2020-01-22 13:36 ` Segher Boessenkool
2020-01-22 14:45 ` Christophe Leroy
2020-01-22 14:45 ` Christophe Leroy
2020-01-22 6:57 ` Christophe Leroy
2020-01-22 6:57 ` Christophe Leroy
2020-01-22 13:18 ` Segher Boessenkool [this message]
2020-01-22 13:18 ` Segher Boessenkool
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