From patchwork Fri Mar 22 08:46:18 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simone Ballarin X-Patchwork-Id: 13599745 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4FA1AC47DD9 for ; Fri, 22 Mar 2024 08:47:23 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.696715.1087862 (Exim 4.92) (envelope-from ) id 1rnaYS-0008Oj-01; Fri, 22 Mar 2024 08:47:12 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 696715.1087862; Fri, 22 Mar 2024 08:47:11 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1rnaYR-0008Nt-Se; Fri, 22 Mar 2024 08:47:11 +0000 Received: by outflank-mailman (input) for mailman id 696715; Fri, 22 Mar 2024 08:47:11 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1rnaYR-0008Hq-Es for xen-devel@lists.xenproject.org; Fri, 22 Mar 2024 08:47:11 +0000 Received: from support.bugseng.com (mail.bugseng.com [162.55.131.47]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id c2ffd4f2-e828-11ee-a1ee-f123f15fe8a2; Fri, 22 Mar 2024 09:47:06 +0100 (CET) Received: from beta.station (net-93-144-106-196.cust.dsl.teletu.it [93.144.106.196]) by support.bugseng.com (Postfix) with ESMTPSA id 9E44C4EE0C8D; Fri, 22 Mar 2024 09:47:08 +0100 (CET) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: c2ffd4f2-e828-11ee-a1ee-f123f15fe8a2 From: Simone Ballarin To: xen-devel@lists.xenproject.org Cc: consulting@bugseng.com, sstabellini@kernel.org, Simone Ballarin , Andrew Cooper , George Dunlap , Jan Beulich , Julien Grall , Wei Liu , Bertrand Marquis , Michal Orzel , Volodymyr Babchuk , =?utf-8?q?Roger_Pau_Monn?= =?utf-8?q?=C3=A9?= Subject: [XEN PATCH v2 2/2] xen: address violations of MISRA C Rule 17.1 Date: Fri, 22 Mar 2024 09:46:18 +0100 Message-Id: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 MISRA C Rule 20.7 states: "The features of `' shall not be used" The Xen community wants to avoid using variadic functions except for specific circumstances where it feels appropriate by strict code review. Functions hypercall_create_continuation and hypercall_xlat_continuation are internal helper functions made to break long running hypercalls into multiple calls. They take a variable number of arguments depending on the original hypercall they are trying to continue. Add SAF deviations for the aforementioned functions. Signed-off-by: Simone Ballarin --- Changes in v2: - replaced "special hypercalls" with "internal helper functions". --- docs/misra/safe.json | 8 ++++++++ xen/arch/arm/domain.c | 1 + xen/arch/x86/hypercall.c | 2 ++ 3 files changed, 11 insertions(+) diff --git a/docs/misra/safe.json b/docs/misra/safe.json index 952324f85c..1145967213 100644 --- a/docs/misra/safe.json +++ b/docs/misra/safe.json @@ -28,6 +28,14 @@ }, { "id": "SAF-3-safe", + "analyser": { + "eclair": "MC3R1.R17.1" + }, + "name": "Rule 17.1: internal helper functions made to break long running hypercalls into multiple calls.", + "text": "They need to take a variable number of arguments depending on the original hypercall they are trying to continue." + }, + { + "id": "SAF-4-safe", "analyser": {}, "name": "Sentinel", "text": "Next ID to be used" diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c index 5e7a7f3e7e..f5706bd5b8 100644 --- a/xen/arch/arm/domain.c +++ b/xen/arch/arm/domain.c @@ -382,6 +382,7 @@ unsigned long hypercall_create_continuation( const char *p = format; unsigned long arg, rc; unsigned int i; + /* SAF-3-safe allowed variadic function */ va_list args; current->hcall_preempted = true; diff --git a/xen/arch/x86/hypercall.c b/xen/arch/x86/hypercall.c index 01cd73040d..18d8c75522 100644 --- a/xen/arch/x86/hypercall.c +++ b/xen/arch/x86/hypercall.c @@ -31,6 +31,7 @@ unsigned long hypercall_create_continuation( const char *p = format; unsigned long arg; unsigned int i; + /* SAF-3-safe allowed variadic function */ va_list args; curr->hcall_preempted = true; @@ -115,6 +116,7 @@ int hypercall_xlat_continuation(unsigned int *id, unsigned int nr, struct cpu_user_regs *regs; unsigned int i, cval = 0; unsigned long nval = 0; + /* SAF-3-safe allowed variadic function */ va_list args; ASSERT(nr <= ARRAY_SIZE(mcs->call.args));