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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5BFEC433EF for ; Tue, 21 Jun 2022 20:38:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245194AbiFUUiH (ORCPT ); Tue, 21 Jun 2022 16:38:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38978 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231259AbiFUUiF (ORCPT ); Tue, 21 Jun 2022 16:38:05 -0400 Received: from mx01.omp.ru (mx01.omp.ru [90.154.21.10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A8BDD10EB for ; Tue, 21 Jun 2022 13:38:03 -0700 (PDT) Received: from [192.168.1.103] (178.176.77.12) by msexch01.omp.ru (10.188.4.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.986.14; Tue, 21 Jun 2022 23:37:55 +0300 Subject: Re: [PATCH] ata: libata-scsi: fix sloppy result type of ata_ioc32() From: Sergey Shtylyov To: Damien Le Moal , References: <4a695619-2de7-671e-7b67-2afddf22423f@omp.ru> <9c231ffe-df3c-9c36-4b8b-dc518009c3d2@opensource.wdc.com> Organization: Open Mobile Platform Message-ID: Date: Tue, 21 Jun 2022 23:37:55 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [178.176.77.12] X-ClientProxiedBy: msexch01.omp.ru (10.188.4.12) To msexch01.omp.ru (10.188.4.12) X-KSE-ServerInfo: msexch01.omp.ru, 9 X-KSE-AntiSpam-Interceptor-Info: scan successful X-KSE-AntiSpam-Version: 5.9.20, Database issued on: 06/21/2022 20:24:58 X-KSE-AntiSpam-Status: KAS_STATUS_NOT_DETECTED X-KSE-AntiSpam-Method: none X-KSE-AntiSpam-Rate: 59 X-KSE-AntiSpam-Info: Lua profiles 171269 [Jun 21 2022] X-KSE-AntiSpam-Info: Version: 5.9.20.0 X-KSE-AntiSpam-Info: Envelope from: s.shtylyov@omp.ru X-KSE-AntiSpam-Info: LuaCore: 491 491 a718ef6dc942138335b0bcd7ab07f27b5c06005e X-KSE-AntiSpam-Info: {rep_avail} X-KSE-AntiSpam-Info: {Tracking_from_domain_doesnt_match_to} X-KSE-AntiSpam-Info: {relay has no DNS name} X-KSE-AntiSpam-Info: {SMTP from is not routable} X-KSE-AntiSpam-Info: {Found in DNSBL: 178.176.77.12 in (user) b.barracudacentral.org} X-KSE-AntiSpam-Info: d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;127.0.0.199:7.1.2;178.176.77.12:7.7.3,7.7.1;omp.ru:7.1.1 X-KSE-AntiSpam-Info: ApMailHostAddress: 178.176.77.12 X-KSE-AntiSpam-Info: {DNS response errors} X-KSE-AntiSpam-Info: Rate: 59 X-KSE-AntiSpam-Info: Status: not_detected X-KSE-AntiSpam-Info: Method: none X-KSE-AntiSpam-Info: Auth:dmarc=temperror header.from=omp.ru;spf=temperror smtp.mailfrom=omp.ru;dkim=none X-KSE-Antiphishing-Info: Clean X-KSE-Antiphishing-ScanningType: Heuristic X-KSE-Antiphishing-Method: None X-KSE-Antiphishing-Bases: 06/21/2022 20:28:00 X-KSE-AttachmentFiltering-Interceptor-Info: protection disabled X-KSE-Antivirus-Interceptor-Info: scan successful X-KSE-Antivirus-Info: Clean, bases: 6/21/2022 4:24:00 PM X-KSE-BulkMessagesFiltering-Scan-Result: InTheLimit Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org On 6/21/22 10:14 PM, Sergey Shtylyov wrote: [...] >>>>> While ata_ioc32() returns *int*, its result gets assigned to and compared >>>>> with the *unsigned long* variable 'val' in ata_sas_scsi_ioctl(), its only >>>>> caller, which implies a problematic implicit cast -- fix that by returning >>>>> *unsigned long* instead. >>>>> >>>>> Found by Linux Verification Center (linuxtesting.org) with the SVACE static >>>>> analysis tool. >>>>> >>>>> Signed-off-by: Sergey Shtylyov >>>>> >>>>> --- >>>>> This patch is against the 'for-next' branch of Damien's 'libata.git' repo. >>>>> >>>>> drivers/ata/libata-scsi.c | 2 +- >>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>> >>>>> Index: libata/drivers/ata/libata-scsi.c >>>>> =================================================================== >>>>> --- libata.orig/drivers/ata/libata-scsi.c >>>>> +++ libata/drivers/ata/libata-scsi.c >>>>> @@ -539,7 +539,7 @@ int ata_task_ioctl(struct scsi_device *s >>>>> return rc; >>>>> } >>>>> >>>>> -static int ata_ioc32(struct ata_port *ap) >>>>> +static unsigned long ata_ioc32(struct ata_port *ap) >>>>> { >>>>> if (ap->flags & ATA_FLAG_PIO_DMA) >>>>> return 1; >>> >>>> Actually, this should be a bool I think and the ioctl code cleaned to use >>> >>> By the ioctl code you mean ata_sas_scsi_ioctl()? >> >> yes. >> >>>> that type since the val argument of the ioctl is also used as a bool. >>> >>> As for HDIO_SET_32BIT, that's prolly OK but what to do with HDIO_GET_32BIT >>> (it calls put_user() on *unsigned long*)? >> >> Something like this should work fine: >> >> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c >> index 86dbb1cdfabd..ec7f79cbb135 100644 >> --- a/drivers/ata/libata-scsi.c >> +++ b/drivers/ata/libata-scsi.c > [...] >> @@ -571,16 +572,16 @@ int ata_sas_scsi_ioctl(struct ata_port *ap, struct >> scsi_device *scsidev, >> return put_user(val, (unsigned long __user *)arg); >> >> case HDIO_SET_32BIT: > > Hmm, I told you this *case* is prolly OK -- it was HDIO_GET_32BIT *case* that > I was concerned about... So you mean that HDIO_GET_32BIT handling should remain > intact? > >> - val = (unsigned long) arg; >> + pio32 = !!((unsigned long) arg); No, this one won't do -- it changes the behavior in case ATA_PFLAG_PIO32CHANGE isn't set... :-/ >> rc = 0; >> spin_lock_irqsave(ap->lock, flags); >> if (ap->pflags & ATA_PFLAG_PIO32CHANGE) { >> - if (val) >> + if (pio32) >> ap->pflags |= ATA_PFLAG_PIO32; >> else >> ap->pflags &= ~ATA_PFLAG_PIO32; >> } else { >> - if (val != ata_ioc32(ap)) >> + if (pio32 != ata_ioc32(ap)) >> rc = -EINVAL; >> } >> spin_unlock_irqrestore(ap->lock, flags); > > Not really sure this is worth it... *unsigned long* result type for > ata_ioc32() seems simpler. Actually, even just modifying ata_ioc32() to return 'bool' produces a seemingly correct code. Note that ata_ioc32() is inlined in any case... MBR, Sergey