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 47237C282DD for ; Thu, 23 May 2019 14:59:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 233412175B for ; Thu, 23 May 2019 14:59:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730910AbfEWO7b (ORCPT ); Thu, 23 May 2019 10:59:31 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:52242 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730719AbfEWO7a (ORCPT ); Thu, 23 May 2019 10:59:30 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out02.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1hTpBo-00030K-MM; Thu, 23 May 2019 08:59:28 -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 1hTpBn-0005AC-PE; Thu, 23 May 2019 08:59:28 -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 09:59:20 -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: <87d0k9gqt3.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=1hTpBn-0005AC-PE;;;mid=<87d0k9gqt3.fsf@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=72.206.97.68;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+nHg2SfTEM+VVuC4vmrmmS7rYHAMpU7QI= X-SA-Exim-Connect-IP: 72.206.97.68 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: [REVIEW][PATCH 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 Will Deacon writes: > On Wed, May 22, 2019 at 07:38:53PM -0500, Eric W. Biederman wrote: >> It really only matters to debuggers but the 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. >> >> 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" >> --- >> arch/arm64/kernel/traps.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c >> index ade32046f3fe..0feb17bdcaa0 100644 >> --- a/arch/arm64/kernel/traps.c >> +++ b/arch/arm64/kernel/traps.c >> @@ -282,6 +282,11 @@ void arm64_notify_die(const char *str, struct pt_regs *regs, >> current->thread.fault_address = 0; >> current->thread.fault_code = err; >> >> + if (signo == SIGKILL) { >> + arm64_show_signal(signo, str); >> + force_sig(signo, current); >> + return; >> + } > > I know it's a bit of a misnomer, but I'd rather do this check inside > arm64_force_sig_fault, since I think we have other callers (e.g. > do_bad_area()) which also blindly pass in SIGKILL here. Sigh. You are right. I thought I had checked for that when I made my change there. But do_bad_area will definitely do that, and that was one of the cases that jumped out at me as needing to be fixed, when I skimmed the arm code. I will respin this patch to move that lower. > We could rename the thing if necessary. I would not mind but as long as we aren't misusing the generic bits I won't have alarm bells going of in my head when I look at their users. Eric