From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f169.google.com (mail-pl1-f169.google.com [209.85.214.169]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C4C8623CC for ; Tue, 15 Mar 2022 18:09:52 +0000 (UTC) Received: by mail-pl1-f169.google.com with SMTP id n15so16894476plh.2 for ; Tue, 15 Mar 2022 11:09:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=LnfhahHm3PDL9lPgihcYM1ixyCrpxkRE4I19AMm+GpI=; b=JVFkFjRzXHvl4p6lzecOm3qCuwJkQk5Aq/4Fikfk7weWrbtXCItQc1wAZya5H6IJDG QNI3GLzgvk3q2YYFCgId9Id3a/AMxyHSRXjdwlpHsKqaZesf5hk2QTOeNe8E421h+niV 56QoMW3xTldNTC6XDzfuHu9lXtWAK74IHih4w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=LnfhahHm3PDL9lPgihcYM1ixyCrpxkRE4I19AMm+GpI=; b=MOoidDPqDJF1peg8oHtwvuK5bMXMUdyzbjg0F2jVjWjfG28Tz33Jw+vwWbJTqbIr6b rBGminVacItFtquAwcfFt4FWm+6fGPSqRWl7FMgCKx3LlTJ76TasUNlk6AiaLv2VLDav /dx4HZLXe4SzW1D6srnbEUMp4xY+5emlqSISAM7RiX2jEU9wAzstxR4FPl3uc3RkMoVi X76afDI4cwUl0KXbtJ2CzDoX0wN8SamTvUWHX1Wx/XcpMgEVplqH4GDEX7x5uzXyJKGW cvf0a870RktlO10JJc0tr4vb5M22/UP2c3YVncxLMcacC/KFDxtJ+mlJST7wlcl/+roJ cSUQ== X-Gm-Message-State: AOAM531bHmY5OdX/chys945YTEq5kEeBwjGCcl9VdDUl8kWn/JHNEl7/ S9ajIHswhcad+U8VPUtvmcfixw== X-Google-Smtp-Source: ABdhPJxrv8JWlmC583Lem9EnnxkdYf2cpc2Vr67JCGAwKnCX6HsrocM0D0dZOBLboyTP/eYhDYcA9Q== X-Received: by 2002:a17:90a:17ab:b0:1bf:9519:fe86 with SMTP id q40-20020a17090a17ab00b001bf9519fe86mr6027447pja.25.1647367792246; Tue, 15 Mar 2022 11:09:52 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id 16-20020a17090a19d000b001c1c6b25cb2sm3736609pjj.26.2022.03.15.11.09.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Mar 2022 11:09:51 -0700 (PDT) Date: Tue, 15 Mar 2022 11:09:51 -0700 From: Kees Cook To: Thomas Bogendoerfer 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: <202203151109.F59911C4CB@keescook> References: <20220309220939.392227-1-keescook@chromium.org> <20220314145215.GD13438@alpha.franken.de> 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: <20220314145215.GD13438@alpha.franken.de> On Mon, Mar 14, 2022 at 03:52:15PM +0100, Thomas Bogendoerfer wrote: > 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. Excellent; thanks very much! -Kees -- Kees Cook