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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 F0139C433E2 for ; Wed, 24 Mar 2021 10:57:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B234661A0D for ; Wed, 24 Mar 2021 10:57:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233433AbhCXK52 (ORCPT ); Wed, 24 Mar 2021 06:57:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60066 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234474AbhCXK4y (ORCPT ); Wed, 24 Mar 2021 06:56:54 -0400 Received: from mail-ed1-x52c.google.com (mail-ed1-x52c.google.com [IPv6:2a00:1450:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B012EC061763 for ; Wed, 24 Mar 2021 03:56:51 -0700 (PDT) Received: by mail-ed1-x52c.google.com with SMTP id h10so27050982edt.13 for ; Wed, 24 Mar 2021 03:56:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ionos.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ToRLObeEBgXor/SnBvKlxaQPAAiDt0hrFEbYVfvSCnc=; b=elEEkbDKetS27RjdVzzPaXDGsWXC+eCWLe3lSxMWM24U6+BEsf71pQbbPS1MT7tRVG A11IyB0kOvl0ZedJAPzv7uOAcohiuwGf+cR4Lq4sSe3DuLfgcrQ83b82UDPHNZp97OIm OkrH/eL56i/9orrRl05h7Rtshwdl5b169LGfxXmkdl+QumjUpoOL9fs8wPsZ8crvT7dL DDHUoHkYlbATU4Ejvkk33BGXkVVlzhnnf7jqfCpzrr/8OG9mLv02MBV8MVz0cmvNohaW 5BrsHEkA1Tc/P/7DvXKJHMygW3zrDzrQGTtMpkjytmu8YyhjqXr9m5fbm6KPMCsODWIR A1OQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ToRLObeEBgXor/SnBvKlxaQPAAiDt0hrFEbYVfvSCnc=; b=JwtABDQ479SGDP5ar+gTPzqWFvMeGk2l6bfLwrx8PadjYCEYRvLe9ZEzN5EI/LfKHr eca+93bXltplB5wjCojaTTm4xg9pXz/XNSPT7VLxlsqM3LjOm39re0SjUcHxfuV+OAu8 FYX7awFdPJI910XnCV4A6UbNcnOi7+yzDo9Q/QOVVxp/sbBhXquuDWNMDfnCFdq6QL9I fpMuhLBnsncIjrDe4gNsqKmAZNl973tfIIF5tVmXyFU9ytFrIAJRyUqQAxrKDWgKplug m9wAYIHGtGFfLdM8NwLX+oEY0o03Q9V0Dfp/gszP80NzmhTr2v1tsO8w9gtKWI1aD7lz WKpA== X-Gm-Message-State: AOAM531jFLVPIpEOYBghT87JlqB0fyT3Qfo6wRqECe0DcFRcQdeJ0PaO Sv+9mIZBsSqv517Q0DL/RCqRZyGxizAciLCfq+E0PQ== X-Google-Smtp-Source: ABdhPJwqlN1J15VG53NhAXyIjEDLmkLNi34PUF7ymALe3cIm19hNqrcFqLDjhEU7wQtAJnwdTKimHEfqlIOTdSRbOiY= X-Received: by 2002:a05:6402:42c9:: with SMTP id i9mr2771463edc.35.1616583410353; Wed, 24 Mar 2021 03:56:50 -0700 (PDT) MIME-Version: 1.0 References: <20210323125458.1825564-1-arnd@kernel.org> In-Reply-To: <20210323125458.1825564-1-arnd@kernel.org> From: Jinpu Wang Date: Wed, 24 Mar 2021 11:56:39 +0100 Message-ID: Subject: Re: [PATCH] scsi: pm8001: avoid -Wrestrict warning To: Arnd Bergmann Cc: Jack Wang , "James E.J. Bottomley" , "Martin K. Petersen" , Arnd Bergmann , Viswas G , Ruksar Devadi , Joe Perches , Vaibhav Gupta , Christophe JAILLET , Lee Jones , Linux SCSI Mailinglist , open list Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 23, 2021 at 1:55 PM Arnd Bergmann wrote: > > From: Arnd Bergmann > > On some configurations, gcc warns about overlapping source and > destination arguments to snprintf: > > drivers/scsi/pm8001/pm8001_init.c: In function 'pm8001_request_msix': > drivers/scsi/pm8001/pm8001_init.c:977:3: error: 'snprintf' argument 4 may overlap destination object 'pm8001_ha' [-Werror=restrict] > 977 | snprintf(drvname, len, "%s-%d", pm8001_ha->name, i); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > drivers/scsi/pm8001/pm8001_init.c:962:56: note: destination object referenced by 'restrict'-qualified argument 1 was declared here > 962 | static u32 pm8001_request_msix(struct pm8001_hba_info *pm8001_ha) > | ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~ > > I first assumed this was a gcc bug, as that should not happen, but > a reduced test case makes it clear that this happens when the loop > counter is not bounded by the array size. > > Help the compiler out by adding an explicit limit here to make the > code slightly more robust and avoid the warning. > > Link: https://godbolt.org/z/6T1qPM > Signed-off-by: Arnd Bergmann Acked-by: Jack Wang > --- > drivers/scsi/pm8001/pm8001_init.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c > index bd626ef876da..a268c647b987 100644 > --- a/drivers/scsi/pm8001/pm8001_init.c > +++ b/drivers/scsi/pm8001/pm8001_init.c > @@ -963,6 +963,7 @@ static u32 pm8001_request_msix(struct pm8001_hba_info *pm8001_ha) > { > u32 i = 0, j = 0; > int flag = 0, rc = 0; > + int nr_irqs = pm8001_ha->number_of_intr; > > if (pm8001_ha->chip_id != chip_8001) > flag &= ~IRQF_SHARED; > @@ -971,7 +972,10 @@ static u32 pm8001_request_msix(struct pm8001_hba_info *pm8001_ha) > "pci_enable_msix request number of intr %d\n", > pm8001_ha->number_of_intr); > > - for (i = 0; i < pm8001_ha->number_of_intr; i++) { > + if (nr_irqs > ARRAY_SIZE(pm8001_ha->intr_drvname)) > + nr_irqs = ARRAY_SIZE(pm8001_ha->intr_drvname); > + > + for (i = 0; i < nr_irqs; i++) { > snprintf(pm8001_ha->intr_drvname[i], > sizeof(pm8001_ha->intr_drvname[0]), > "%s-%d", pm8001_ha->name, i); > -- > 2.29.2 >