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[23.128.96.18]) by mx.google.com with ESMTP id c61si9784128edd.310.2021.06.26.03.39.55; Sat, 26 Jun 2021 03:40:19 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229657AbhFZKlM (ORCPT + 99 others); Sat, 26 Jun 2021 06:41:12 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:40461 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229518AbhFZKlL (ORCPT ); Sat, 26 Jun 2021 06:41:11 -0400 Received: by ozlabs.org (Postfix, from userid 1034) id 4GBr2H5xmCz9sfG; Sat, 26 Jun 2021 20:38:47 +1000 (AEST) From: Michael Ellerman To: Michael Ellerman , Arnd Bergmann Cc: linuxppc-dev@lists.ozlabs.org, Paul Mackerras , Ravi Bangoria , Arnd Bergmann , Benjamin Herrenschmidt , Christophe Leroy , linux-kernel@vger.kernel.org, Nicholas Piggin In-Reply-To: <20210429080708.1520360-1-arnd@kernel.org> References: <20210429080708.1520360-1-arnd@kernel.org> Subject: Re: [PATCH] powerpc: mark local variables around longjmp as volatile Message-Id: <162470384692.3589875.5670173938477292479.b4-ty@ellerman.id.au> Date: Sat, 26 Jun 2021 20:37:26 +1000 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 29 Apr 2021 10:06:38 +0200, Arnd Bergmann wrote: > gcc-11 points out that modifying local variables next to a > longjmp/setjmp may cause undefined behavior: > > arch/powerpc/kexec/crash.c: In function 'crash_kexec_prepare_cpus.constprop': > arch/powerpc/kexec/crash.c:108:22: error: variable 'ncpus' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbere > d] > arch/powerpc/kexec/crash.c:109:13: error: variable 'tries' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbere > d] > arch/powerpc/xmon/xmon.c: In function 'xmon_print_symbol': > arch/powerpc/xmon/xmon.c:3625:21: error: variable 'name' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] > arch/powerpc/xmon/xmon.c: In function 'stop_spus': > arch/powerpc/xmon/xmon.c:4057:13: error: variable 'i' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] > arch/powerpc/xmon/xmon.c: In function 'restart_spus': > arch/powerpc/xmon/xmon.c:4098:13: error: variable 'i' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] > arch/powerpc/xmon/xmon.c: In function 'dump_opal_msglog': > arch/powerpc/xmon/xmon.c:3008:16: error: variable 'pos' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] > arch/powerpc/xmon/xmon.c: In function 'show_pte': > arch/powerpc/xmon/xmon.c:3207:29: error: variable 'tsk' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] > arch/powerpc/xmon/xmon.c: In function 'show_tasks': > arch/powerpc/xmon/xmon.c:3302:29: error: variable 'tsk' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] > arch/powerpc/xmon/xmon.c: In function 'xmon_core': > arch/powerpc/xmon/xmon.c:494:13: error: variable 'cmd' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] > arch/powerpc/xmon/xmon.c:860:21: error: variable 'bp' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] > arch/powerpc/xmon/xmon.c:860:21: error: variable 'bp' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] > arch/powerpc/xmon/xmon.c:492:48: error: argument 'fromipi' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] > > [...] Applied to powerpc/next. [1/1] powerpc: mark local variables around longjmp as volatile https://git.kernel.org/powerpc/c/a2305e3de819394a7adf68078964a92d06f9db33 cheers