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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 3E9B4C3A5A7 for ; Wed, 4 Sep 2019 10:47:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1670122CED for ; Wed, 4 Sep 2019 10:47:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727351AbfIDKry (ORCPT ); Wed, 4 Sep 2019 06:47:54 -0400 Received: from foss.arm.com ([217.140.110.172]:51720 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725840AbfIDKry (ORCPT ); Wed, 4 Sep 2019 06:47:54 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A9277337; Wed, 4 Sep 2019 03:47:53 -0700 (PDT) Received: from arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DD2743F246; Wed, 4 Sep 2019 03:47:52 -0700 (PDT) Date: Wed, 4 Sep 2019 11:47:50 +0100 From: Dave Martin To: Cristian Marussi Cc: andreyknvl@google.com, shuah@kernel.org, linux-kselftest@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v3 06/11] kselftest: arm64: fake_sigreturn_bad_magic Message-ID: <20190904104750.GO27757@arm.com> References: <20190802170300.20662-1-cristian.marussi@arm.com> <20190802170300.20662-7-cristian.marussi@arm.com> <20190813162523.GD10425@arm.com> <245a3d64-2790-1768-94ab-d1ea56aa3d3d@arm.com> <20190904100516.GN27757@arm.com> <1ae402d4-4fe0-9541-4e18-d432f88fc6bb@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1ae402d4-4fe0-9541-4e18-d432f88fc6bb@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Wed, Sep 04, 2019 at 11:37:36AM +0100, Cristian Marussi wrote: > On 04/09/2019 11:05, Dave Martin wrote: > > On Fri, Aug 30, 2019 at 03:29:29PM +0100, Cristian Marussi wrote: > >> Hi > >> > >> On 13/08/2019 17:25, Dave Martin wrote: > >>> On Fri, Aug 02, 2019 at 06:02:55PM +0100, Cristian Marussi wrote: > > > > [...] > > > >>>> diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_magic.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_magic.c > > > > [...] > > > >>>> +static int fake_sigreturn_bad_magic_run(struct tdescr *td, > >>>> + siginfo_t *si, ucontext_t *uc) > >>>> +{ > >>>> + size_t resv_sz, offset; > >>>> + struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head; > >>>> + > >>>> + /* just to fill the ucontext_t with something real */ > >>>> + if (!get_current_context(td, &sf.uc)) > >>>> + return 1; > >>>> + > >>>> + resv_sz = GET_SF_RESV_SIZE(sf); > >>>> + /* > >>>> + * find the terminator, preserving existing headers > >>>> + * and verify amount of spare room in __reserved area. > >>>> + */ > >>>> + head = get_terminator(shead, resv_sz, &offset); > >>>> + /* > >>>> + * try stripping extra_context header when low on space: > >>>> + * we need at least 2*HDR_SZ space ... one for the KSFT_BAD_MAGIC > >>>> + * and the other for the usual terminator. > >>>> + */ > >>>> + if (head && resv_sz - offset < HDR_SZ * 2) { > >>> > >>> Can we factor out this logic for finding space in the signal frame? > >>> > >>> We do pretty much the same thing in all the fake_sigreturn tests... > >> > >> Ok > >>> > >>>> + fprintf(stderr, "Low on space:%zd. Discarding extra_context.\n", > >>>> + resv_sz - offset); > >>>> + head = get_header(shead, EXTRA_MAGIC, resv_sz, &offset); > >>>> + } > >>>> + /* just give up and timeout if still not enough space */ > >>> > >>> Do we actually time out? I don't see where we actually wait, so doesn't > >>> test_run() just fail immediately? > >>> > >>> The same applies to all the other fake_sigreturn tests too. > >>> > >> Right. It is probably a leftover. > >> > >> SIGALRM is used as an extreme measure to kill tests gone bad, but this > >> can happen only once the fake sigframe has been effectively placed on the stack > >> and sigreturned. > > > > OK, so this gets reported as a test failure because with no SIGSEGV, > > nothing ever sets td->pass? > > Yes exactly. End result is based on value on td->pass, in case of abrupt > termination or timeout nobody sets td->pass ever. > > > > This is probably OK for now, though I wonder whether this should be > > reported as a skipped test instead. > > > > In case of doubt, reporting a failure is preferable anyway, since that > > will encourage people actually to investigate what went wrong. > > > > As of now I never skip a test in fact...also tests for unsupported features > are built and run expecting a SIGILL, and reported as PASS in that case. OK, just wanted to check I'd understood correcly. Cheers ---Dave