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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 9D97DC3A59B for ; Fri, 30 Aug 2019 14:49:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7DB3720659 for ; Fri, 30 Aug 2019 14:49:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727958AbfH3Otj (ORCPT ); Fri, 30 Aug 2019 10:49:39 -0400 Received: from foss.arm.com ([217.140.110.172]:33410 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727809AbfH3Otj (ORCPT ); Fri, 30 Aug 2019 10:49:39 -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 87D34344; Fri, 30 Aug 2019 07:49:38 -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 D0FEC3F703; Fri, 30 Aug 2019 07:49:37 -0700 (PDT) Subject: Re: [PATCH v3 07/11] kselftest: arm64: fake_sigreturn_bad_size_for_magic0 To: Dave Martin Cc: linux-kselftest@vger.kernel.org, linux-arm-kernel@lists.infradead.org, shuah@kernel.org, andreyknvl@google.com References: <20190802170300.20662-1-cristian.marussi@arm.com> <20190802170300.20662-8-cristian.marussi@arm.com> <20190813162550.GE10425@arm.com> From: Cristian Marussi Message-ID: <1a4f4b81-d8fa-ece3-125d-6235b8972bbb@arm.com> Date: Fri, 30 Aug 2019 15:49:35 +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: <20190813162550.GE10425@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 13/08/2019 17:25, Dave Martin wrote: > On Fri, Aug 02, 2019 at 06:02:56PM +0100, Cristian Marussi wrote: >> Added a simple fake_sigreturn testcase which builds a ucontext_t > > Add Ok > >> with a badly sized magic0 header and place it onto the stack. > > I usually call a record with magic number 0 a "terminator record". > Ok >> Expects a SIGSEGV on test PASS. >> >> Signed-off-by: Cristian Marussi >> --- >> .../arm64/signal/testcases/.gitignore | 1 + >> .../fake_sigreturn_bad_size_for_magic0.c | 57 +++++++++++++++++++ >> 2 files changed, 58 insertions(+) >> create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c >> >> diff --git a/tools/testing/selftests/arm64/signal/testcases/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore >> index 0ea6fdc3765c..cf2a73599818 100644 >> --- a/tools/testing/selftests/arm64/signal/testcases/.gitignore >> +++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore >> @@ -5,3 +5,4 @@ mangle_pstate_invalid_mode_el2 >> mangle_pstate_invalid_mode_el3 >> mangle_pstate_ssbs_regs >> fake_sigreturn_bad_magic >> +fake_sigreturn_bad_size_for_magic0 >> diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c >> new file mode 100644 >> index 000000000000..2f53c4740c85 >> --- /dev/null >> +++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c >> @@ -0,0 +1,57 @@ >> +/* SPDX-License-Identifier: GPL-2.0 */ >> +/* Copyright (C) 2019 ARM Limited */ >> + > > #include ? > Ok >> +#include >> +#include >> + >> +#include "test_signals_utils.h" >> +#include "testcases.h" >> + >> +struct fake_sigframe sf; >> + >> +#define MIN_SZ_ALIGN 16 >> + >> +static int fake_sigreturn_bad_size_for_magic0_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 HDR_SZ + 16 space for the bad sized terminator. >> + */ >> + if (head && resv_sz - offset < HDR_SZ + MIN_SZ_ALIGN) { >> + 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 */ >> + if (head && resv_sz - offset >= HDR_SZ + MIN_SZ_ALIGN) { >> + head->magic = 0; >> + head->size = MIN_SZ_ALIGN; > > This is different from the amount of space we tested for > (HDR_SZ + MIN_SZ_ALIGN) earlier. > > I'm not sure it matters which we use, but we should be consistent. > > I suggest sticking with HDR_SZ, unless there's something I've missed. > I'll stick to HDR_SZ in this case and use the new helper from 06/11 (get_starting_head) > [...] > > Cheers > ---Dave > Cheers Cristian