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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 AB133C282DD for ; Thu, 23 May 2019 16:11:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8851C2175B for ; Thu, 23 May 2019 16:11:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731151AbfEWQL3 (ORCPT ); Thu, 23 May 2019 12:11:29 -0400 Received: from out03.mta.xmission.com ([166.70.13.233]:40765 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730782AbfEWQL3 (ORCPT ); Thu, 23 May 2019 12:11:29 -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 1hTqJT-0007EP-Fv; Thu, 23 May 2019 10:11:27 -0600 Received: from ip72-206-97-68.om.om.cox.net ([72.206.97.68] helo=x220.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1hTqJS-0001D2-BB; Thu, 23 May 2019 10:11:27 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Will Deacon Cc: linux-kernel@vger.kernel.org, Linux Containers , Oleg Nesterov , linux-arch@vger.kernel.org, Dave Martin , James Morse References: <20190523003916.20726-1-ebiederm@xmission.com> <20190523003916.20726-4-ebiederm@xmission.com> <20190523101702.GG26646@fuggles.cambridge.arm.com> Date: Thu, 23 May 2019 11:11:19 -0500 In-Reply-To: <20190523101702.GG26646@fuggles.cambridge.arm.com> (Will Deacon's message of "Thu, 23 May 2019 11:17:02 +0100") Message-ID: <875zq1gnh4.fsf_-_@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1hTqJS-0001D2-BB;;;mid=<875zq1gnh4.fsf_-_@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=72.206.97.68;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX18uM7KSAne4UR9ryYOSFz6/61hVMF9pJiQ= X-SA-Exim-Connect-IP: 72.206.97.68 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [REVIEW][PATCHv2 03/26] signal/arm64: Use force_sig not force_sig_fault for SIGKILL 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 I don't think this is userspace visible but SIGKILL does not have any si_codes that use the fault member of the siginfo union. Correct this the simple way and call force_sig instead of force_sig_fault when the signal is SIGKILL. The two know places where synchronous SIGKILL are generated are do_bad_area and fpsimd_save. The call paths to force_sig_fault are: do_bad_area arm64_force_sig_fault force_sig_fault force_signal_inject arm64_notify_die arm64_force_sig_fault force_sig_fault Which means correcting this in arm64_force_sig_fault is enough to ensure the arm64 code is not misusing the generic code, which could lead to maintenance problems later. Cc: stable@vger.kernel.org Cc: Dave Martin Cc: James Morse Cc: Will Deacon Fixes: af40ff687bc9 ("arm64: signal: Ensure si_code is valid for all fault signals") Signed-off-by: "Eric W. Biederman" --- I have also made the corresponding changes to: 09/26 signal: Remove task parameter from force_sig 21/26 signal: Remove the task parameter from force_sig_fault But I will leave off reposting those as for now as the changes are obvious. arch/arm64/kernel/traps.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index ade32046f3fe..e45d5b440fb1 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -256,7 +256,10 @@ void arm64_force_sig_fault(int signo, int code, void __user *addr, const char *str) { arm64_show_signal(signo, str); - force_sig_fault(signo, code, addr, current); + if (signo == SIGKILL) + force_sig(SIGKILL, current); + else + force_sig_fault(signo, code, addr, current); } void arm64_force_sig_mceerr(int code, void __user *addr, short lsb, -- 2.21.0.dirty