From patchwork Fri Oct 18 12:48:18 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: tip-bot2 for Nam Cao X-Patchwork-Id: 11198415 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EA18A69B7 for ; Fri, 18 Oct 2019 13:07:37 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CFB792070B for ; Fri, 18 Oct 2019 13:07:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CFB792070B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iLRw4-0000rl-T9; Fri, 18 Oct 2019 13:04:52 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1iLRgK-0007mx-OM for xen-devel@lists.xenproject.org; Fri, 18 Oct 2019 12:48:36 +0000 X-Inumbo-ID: 974e38f0-f1a5-11e9-bbab-bc764e2007e4 Received: from Galois.linutronix.de (unknown [2a0a:51c0:0:12e:550::1]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 974e38f0-f1a5-11e9-bbab-bc764e2007e4; Fri, 18 Oct 2019 12:48:32 +0000 (UTC) Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1iLRg2-00078J-T1; Fri, 18 Oct 2019 14:48:18 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 5E5E11C009C; Fri, 18 Oct 2019 14:48:18 +0200 (CEST) Date: Fri, 18 Oct 2019 12:48:18 -0000 From: "tip-bot2 for Masami Hiramatsu" To: linux-tip-commits@vger.kernel.org In-Reply-To: <156777566048.25081.6296162369492175325.stgit@devnote2> References: <156777566048.25081.6296162369492175325.stgit@devnote2> MIME-Version: 1.0 Message-ID: <157140289814.29376.7139596484011081680.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1, SHORTCIRCUIT=-0.0001 X-Mailman-Approved-At: Fri, 18 Oct 2019 13:04:51 +0000 Subject: [Xen-devel] [tip: x86/core] x86: kprobes: Prohibit probing on instruction which has emulate prefix X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Reply-To: linux-kernel@vger.kernel.org Cc: Juergen Gross , Stefano Stabellini , "Peter Zijlstra \(Intel\)" , Andrew Cooper , x86@kernel.org, linux-kernel@vger.kernel.org, Borislav Petkov , Masami Hiramatsu , Josh Poimboeuf , xen-devel@lists.xenproject.org, Boris Ostrovsky , Randy Dunlap , Ingo Molnar Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" The following commit has been merged into the x86/core branch of tip: Commit-ID: 004e8dce9c5595697951f7cd0e9f66b35c92265e Gitweb: https://git.kernel.org/tip/004e8dce9c5595697951f7cd0e9f66b35c92265e Author: Masami Hiramatsu AuthorDate: Fri, 06 Sep 2019 22:14:20 +09:00 Committer: Peter Zijlstra CommitterDate: Thu, 17 Oct 2019 21:31:57 +02:00 x86: kprobes: Prohibit probing on instruction which has emulate prefix Prohibit probing on instruction which has XEN_EMULATE_PREFIX or KVM's emulate prefix. Since that prefix is a marker for Xen and KVM, if we modify the marker by kprobe's int3, that doesn't work as expected. Signed-off-by: Masami Hiramatsu Signed-off-by: Peter Zijlstra (Intel) Cc: Juergen Gross Cc: x86@kernel.org Cc: Boris Ostrovsky Cc: Ingo Molnar Cc: Stefano Stabellini Cc: Andrew Cooper Cc: Borislav Petkov Cc: xen-devel@lists.xenproject.org Cc: Randy Dunlap Cc: Josh Poimboeuf Link: https://lkml.kernel.org/r/156777566048.25081.6296162369492175325.stgit@devnote2 --- arch/x86/kernel/kprobes/core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 43fc13c..4f13af7 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -351,6 +351,10 @@ int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct insn *insn) kernel_insn_init(insn, dest, MAX_INSN_SIZE); insn_get_length(insn); + /* We can not probe force emulate prefixed instruction */ + if (insn_has_emulate_prefix(insn)) + return 0; + /* Another subsystem puts a breakpoint, failed to recover */ if (insn->opcode.bytes[0] == BREAKPOINT_INSTRUCTION) return 0;