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 6513FC3A5A7 for ; Wed, 4 Sep 2019 10:37:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 41C0A2339E for ; Wed, 4 Sep 2019 10:37:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728951AbfIDKhl (ORCPT ); Wed, 4 Sep 2019 06:37:41 -0400 Received: from foss.arm.com ([217.140.110.172]:51514 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726304AbfIDKhl (ORCPT ); Wed, 4 Sep 2019 06:37:41 -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 BA54A337; Wed, 4 Sep 2019 03:37:40 -0700 (PDT) Received: from [10.1.197.50] (e120937-lin.cambridge.arm.com [10.1.197.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 10B453F246; Wed, 4 Sep 2019 03:37:39 -0700 (PDT) Subject: Re: [PATCH v3 06/11] kselftest: arm64: fake_sigreturn_bad_magic To: Dave Martin Cc: andreyknvl@google.com, shuah@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org 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> From: Cristian Marussi Message-ID: <1ae402d4-4fe0-9541-4e18-d432f88fc6bb@arm.com> Date: Wed, 4 Sep 2019 11:37:36 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190904100516.GN27757@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org 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. Cristian > [...] > > Cheers > ---Dave >