From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from elvis.franken.de (elvis.franken.de [193.175.24.41]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 728941B73 for ; Mon, 14 Mar 2022 15:26:13 +0000 (UTC) Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1nTm4O-0006nG-01; Mon, 14 Mar 2022 15:53:12 +0100 Received: by alpha.franken.de (Postfix, from userid 1000) id C5EC0C2E31; Mon, 14 Mar 2022 15:52:15 +0100 (CET) Date: Mon, 14 Mar 2022 15:52:15 +0100 From: Thomas Bogendoerfer To: Kees Cook Cc: Nathan Chancellor , Marc Zyngier , Guenter Roeck , Yanteng Si , linux-mips@vger.kernel.org, Nick Desaulniers , Mark Rutland , linux-kernel@vger.kernel.org, llvm@lists.linux.dev, linux-hardening@vger.kernel.org Subject: Re: [PATCH v2] MIPS: Only use current_stack_pointer on GCC Message-ID: <20220314145215.GD13438@alpha.franken.de> References: <20220309220939.392227-1-keescook@chromium.org> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220309220939.392227-1-keescook@chromium.org> User-Agent: Mutt/1.10.1 (2018-07-13) On Wed, Mar 09, 2022 at 02:09:39PM -0800, Kees Cook wrote: > Unfortunately, Clang did not have support for "sp" as a global register > definition, and was crashing after the addition of current_stack_pointer. > This has been fixed in Clang 15, but earlier Clang versions need to > avoid this code, so add a versioned test and revert back to the > open-coded asm instances. Fixes Clang build error: > > fatal error: error in backend: Invalid register name global variable > > Fixes: 200ed341b864 ("mips: Implement "current_stack_pointer"") > Reported-by: Nathan Chancellor > Reviewed-by: Nathan Chancellor > Link: https://lore.kernel.org/lkml/YikTQRql+il3HbrK@dev-arch.thelio-3990X > Cc: Thomas Bogendoerfer > Cc: Marc Zyngier > Cc: Guenter Roeck > Cc: Yanteng Si > Cc: linux-mips@vger.kernel.org > Signed-off-by: Kees Cook > --- > v1: https://lore.kernel.org/lkml/20220309204537.390428-1-keescook@chromium.org > v2: - adjust Clang version (Nathan) > --- > arch/mips/Kconfig | 2 +- > arch/mips/include/asm/thread_info.h | 2 ++ > arch/mips/kernel/irq.c | 3 ++- > arch/mips/lib/uncached.c | 4 +++- > 4 files changed, 8 insertions(+), 3 deletions(-) applied to mips-next with the Clang version in the decscription fixed. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]