Received: by 10.192.165.148 with SMTP id m20csp3567373imm; Mon, 7 May 2018 14:42:21 -0700 (PDT) X-Google-Smtp-Source: AB8JxZq7FvZwDvfq2NKjXunZM/a6FD+dVHupL3O7IQrYF5GYHu7FAWOgbxKnoE34JG2bITSqWr5a X-Received: by 10.98.215.81 with SMTP id v17mr37506856pfl.39.1525729341870; Mon, 07 May 2018 14:42:21 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1525729341; cv=none; d=google.com; s=arc-20160816; b=CYTtUEaaueJ8gNcMZD9vILjSjZrnSFCglS3vgzVf7g1yJt8gXax3D4SvQczApY3tIz 5iDubgk3VeSIsmRfvLifee7jGLQpNE748JaBM8giTY3dWiME2dEH1gChD5hnZX71BOTO g3Clx7m+djHT6bYK1P5b/nVhmcR3RS5MU/7cgq1irCdheQUGdq3tPtaqUB0ul2fYXl62 +6xExW8oT81NLjkNhbF/KW4urvsUL+LyCzH7weDFR0cKHQKrTVnv9+CgDOu+8LWTNygk VWMkKL5mPzqf6d0JtTptWl1OawSQ+gerkNpd5joH7GymKJDMaT7oNSnRajwYP9pmCJSn SW6w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:message-id:from:cc:to:subject :content-transfer-encoding:mime-version:references:in-reply-to :user-agent:date:arc-authentication-results; bh=BIS8udywCeaz0HGZcFyylw5UlrkEW7/A8RUw8Z1Txo4=; b=CwXglHpgehkgc0PNAQSFdQMqP6ZU//+rWYgvEqr2RFVcci2fEki1fLoWbXSMw7PCzI Pr119k7OaiMS1TTc1JzXLDGKxHFkwJEDu+0PGhQ+GUL6HHPL2uX7MFxAwlksWE8f/98x afOy7l2YeryBxhkAlsNiCAML3ibPfIZcDf5fvlEku8HGKmUY6Qkb7tpngEHgK+AgTzRs Y8YDDaQbXp0efL8Wb1iMHgCGW43jVUcIr9Z4OpcpjBE0ZMpU3/mcdfQUUDXGBvVlDbcG x1bgkxEWCdX6ke7TsnZIPV/R1TzW01/0WyboT+zEv3p92TCvl7buzMDNyQnwcsCyku7Q g9cw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id c21-v6si18429214pgn.355.2018.05.07.14.42.07; Mon, 07 May 2018 14:42:21 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753146AbeEGVlb convert rfc822-to-8bit (ORCPT + 99 others); Mon, 7 May 2018 17:41:31 -0400 Received: from terminus.zytor.com ([198.137.202.136]:51653 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753102AbeEGVla (ORCPT ); Mon, 7 May 2018 17:41:30 -0400 Received: from wld62.hos.anvin.org (c-24-5-245-234.hsd1.ca.comcast.net [24.5.245.234] (may be forged)) (authenticated bits=0) by mail.zytor.com (8.15.2/8.15.2) with ESMTPSA id w47LfKs82312684 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO); Mon, 7 May 2018 14:41:21 -0700 Date: Mon, 07 May 2018 14:41:14 -0700 User-Agent: K-9 Mail for Android In-Reply-To: <20180507213755.GA32406@avx2> References: <20180507213755.GA32406@avx2> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Subject: Re: [PATCH] x86: pad assembly functions with INT3 To: Alexey Dobriyan , tglx@linutronix.de, mingo@redhat.com CC: linux-kernel@vger.kernel.org, x86@kernel.org From: hpa@zytor.com Message-ID: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On May 7, 2018 2:37:55 PM PDT, Alexey Dobriyan wrote: >Use INT3 instead of NOP. All that padding between functions is >an illegal area, no legitimate code should jump into it. > >I've checked x86_64 allyesconfig disassembly, all changes looks sane: >INT3 is only used after RET or unconditional JMP. > >Signed-off-by: Alexey Dobriyan >--- > > arch/x86/include/asm/linkage.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > >--- a/arch/x86/include/asm/linkage.h >+++ b/arch/x86/include/asm/linkage.h >@@ -18,7 +18,7 @@ > name: > > #if defined(CONFIG_X86_64) || defined(CONFIG_X86_ALIGNMENT_16) >-#define __ALIGN .p2align 4, 0x90 >+#define __ALIGN .p2align 4, 0xCC > #define __ALIGN_STR __stringify(__ALIGN) > #endif > Acked-by: H. Peter Anvin -- Sent from my Android device with K-9 Mail. Please excuse my brevity.