From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C538EC433F5 for ; Tue, 26 Oct 2021 17:17:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ACBAB60296 for ; Tue, 26 Oct 2021 17:17:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237586AbhJZRTb (ORCPT ); Tue, 26 Oct 2021 13:19:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38438 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230160AbhJZRTa (ORCPT ); Tue, 26 Oct 2021 13:19:30 -0400 Received: from mail-pf1-x434.google.com (mail-pf1-x434.google.com [IPv6:2607:f8b0:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C971FC061745 for ; Tue, 26 Oct 2021 10:17:06 -0700 (PDT) Received: by mail-pf1-x434.google.com with SMTP id v193so128321pfc.4 for ; Tue, 26 Oct 2021 10:17:06 -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=jS/Bb8HlBeXqBieknFa/sF/Lj+vFn0yJ+1yyDaWDOro=; b=SlbA97RgFmReoxDo2sQ4uaMAJ1WFI/4jMnoGIQG+HMpFaWq8WZVWBYz3HE7O19AAhI N9AGWBiYUy+cDOfw3nlYPFSOcRBlDPjNwTJTvB96MMZT3UHHaap4Qoh2XJTHzL4WYbRn thoBlvHlxlooKrUCBZjGCXL3NJoBML/xdDfMs= 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=jS/Bb8HlBeXqBieknFa/sF/Lj+vFn0yJ+1yyDaWDOro=; b=ZkAyBCSZw9MxOIo3Eft5NW9Lp+Rx+eFPbHdkMVupkBm49w3Vpp7FAK3hdWfSzerRJL 7e4GX1p+59cFhUURutLnujNP8VjR6Ktv8mSg34Y2BjY/9Cle05fqo73mG1pVEV7v9aj6 m1CGvKtJ5K+cHMaRlQl+hDvm/Ar0+9j452B4C6ilyGaNNifejjcr4UbHfNtLnoaBQGw9 FMRGfc4nq7CEEabnYZILKUoMvuSD0O50agXk8ZzeTO+/DE7gILL+n0qx7n0Md9Bj1QD/ dD/JSP2cZTf0c+ChoOAKMc6JPcB+sBIKKFslkN3EBj64AbSqKQ2d05cYVSkyB/PiYVY4 ecpQ== X-Gm-Message-State: AOAM533a5/g0eNSO7BSSUNq5Z5pL3+x20XccV5MtKeRECd5poCwuaLB7 Z0SSYe6VSLB+GD84b0JAECtekA== X-Google-Smtp-Source: ABdhPJy3wcwbRrDjTLAyIluKSke1KBFc/7opoyClAa4a0Aad9xqEBPHL5L/WIQBY6FtASto34NbzBw== X-Received: by 2002:a05:6a00:b92:b0:47b:e437:9ba with SMTP id g18-20020a056a000b9200b0047be43709bamr18624429pfj.39.1635268626307; Tue, 26 Oct 2021 10:17:06 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id u193sm18979323pgc.34.2021.10.26.10.17.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Oct 2021 10:17:05 -0700 (PDT) Date: Tue, 26 Oct 2021 10:17:05 -0700 From: Kees Cook To: Ard Biesheuvel Cc: linux-arm-kernel@lists.infradead.org, Nick Desaulniers , linux-hardening@vger.kernel.org Subject: Re: [PATCH] ARM: stackprotector: prefer compiler for TLS based per-task protector Message-ID: <202110261015.D992D69@keescook> References: <20211021142516.1843042-1-ardb@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211021142516.1843042-1-ardb@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org On Thu, Oct 21, 2021 at 04:25:16PM +0200, Ard Biesheuvel wrote: > Currently, we implement the per-task stack protector for ARM using a GCC > plugin, due to lack of native compiler support. However, work is > underway to get this implemented in the compiler, which means we will be > able to deprecate the GCC plugin at some point. > > In the meantime, we will need to support both, where the native compiler > implementation is obviously preferred. So let's wire this up in Kconfig > and the Makefile. > > Cc: Kees Cook > Cc: Nick Desaulniers > Signed-off-by: Ard Biesheuvel With the v3 GCC patch[1], this works for me. Thanks! Acked-by: Kees Cook And since this is doing a compiler feature-test, this can get landed without waiting for GCC, IMO. -Kees [1] https://lore.kernel.org/linux-hardening/20211026081836.3518758-2-ardb@kernel.org/ -- Kees Cook