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 X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 728F9C43334 for ; Mon, 3 Sep 2018 20:45:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 321AD20645 for ; Mon, 3 Sep 2018 20:45:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 321AD20645 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xmission.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729016AbeIDBHM (ORCPT ); Mon, 3 Sep 2018 21:07:12 -0400 Received: from out03.mta.xmission.com ([166.70.13.233]:50350 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728386AbeIDBHM (ORCPT ); Mon, 3 Sep 2018 21:07:12 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out03.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1fwvin-00063B-UR; Mon, 03 Sep 2018 14:45:17 -0600 Received: from [105.225.206.69] (helo=x220.Home) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_CBC_SHA256:128) (Exim 4.87) (envelope-from ) id 1fwvim-0008G7-TX; Mon, 03 Sep 2018 14:45:17 -0600 From: "Eric W. Biederman" To: linux-kernel@vger.kernel.org Cc: Oleg Nesterov , Linus Torvalds , linux-api@vger.kernel.org, "Eric W. Biederman" Date: Mon, 3 Sep 2018 22:44:23 +0200 Message-Id: <20180903204430.25473-3-ebiederm@xmission.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <87musyl3fa.fsf@xmission.com> References: <87musyl3fa.fsf@xmission.com> X-XM-SPF: eid=1fwvim-0008G7-TX;;;mid=<20180903204430.25473-3-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=105.225.206.69;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1/VY318Kl8JxdGHBdk5QZUwdtcxtuSxgQg= X-SA-Exim-Connect-IP: 105.225.206.69 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH 03/10] signal: Properly deliver SIGSEGV from x86 uprobes X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For userspace to tell the difference between an random signal and an exception, the exception must include siginfo information. Using SEND_SIG_FORCED for SIGSEGV is thus wrong, and it will result in userspace seeing si_code == SI_USER (like a random signal) instead of si_code == SI_KERNEL or a more specific si_code as all exceptions deliver. Therefore replace force_sig_info(SIGSEGV, SEND_SIG_FORCE, current) with force_sig(SIG_SEGV, current) which gets this right and is shorter and easier to type. Fixes: 791eca10107f ("uretprobes/x86: Hijack return address") Signed-off-by: "Eric W. Biederman" --- arch/x86/kernel/uprobes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index deb576b23b7c..843feb94a950 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -1086,7 +1086,7 @@ arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs pr_err("return address clobbered: pid=%d, %%sp=%#lx, %%ip=%#lx\n", current->pid, regs->sp, regs->ip); - force_sig_info(SIGSEGV, SEND_SIG_FORCED, current); + force_sig(SIGSEGV, current); } return -1; -- 2.17.1