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=-14.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 05823C433E9 for ; Tue, 9 Feb 2021 10:58:53 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7F08964E26 for ; Tue, 9 Feb 2021 10:58:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7F08964E26 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bfs.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:In-Reply-To:References:Message-ID:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=6C3jf+lzzCHHgvSIwqx+z0/cQLvcvwE/xIamWOorDn4=; b=JiQuQAi88ebekvtNFv7lcBgpw G02UGXJ1oQJPApc7d0iYniCUXhT5/DrsOrWOSsij38tavIk/JM56m2UFQUgcXMzdITiH1uQNMTFpx gu/yDDf0SFcbV76zJmcpNZcuHXqUvCH6BAEddr7l2IoYuudY9nLD1D3btXgnQSwm8G+anRORXDBmZ M9VdWzn7zBu5UdykQobDAQUsFA46mbZTDRwTq2+g7DS4N96w0ZOYr6xM2QsFGysA83EqqSfcN9qwX N4Tvu7SujbillJfAYsdcz0LLWWykK11CsVzZv/z3/qal56mCJocGee3EOHF0cSYZN2tMjA3/EMOoj GnrqXBDrw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l9QiF-0005Oc-0i; Tue, 09 Feb 2021 10:57:43 +0000 Received: from mx01-sz.bfs.de ([194.94.69.67]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l9QiC-0005LV-21; Tue, 09 Feb 2021 10:57:41 +0000 Received: from SRVEX01-SZ.bfs.intern (exchange-sz.bfs.de [10.129.90.31]) by mx01-sz.bfs.de (Postfix) with ESMTPS id DABFE2076E; Tue, 9 Feb 2021 11:57:32 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bfs.de; s=dkim201901; t=1612868252; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=F1DfsCqs88iiQXx9DWuj57ZejBv/iB8OwGlMzxeON1g=; b=L+XB+9cKSQKPGfxZSR9SZuyPfdtlbofqolBjxsYSYkQtzW0FtR5MScz8D3qZ3c2xRn/0sV +Ej7sWzVqYbx+Qc/bHWjYvIKEozDvX6Sm9kIQ1u43f/Noc2sATXR09ggbiSnDsZ8EADFm+ Tcn5Rsec2RYzMpPYc1gduwH6C5LyRb9PowHLp26kqTTv49t2ACE3UoyB/PdljEC6QevGff FxT5qN+DSAtEwUfgWW+IKU7eiE/GWXik59pkL0zsEazLhb+2dyWpkKlxlTPKHusnOu/1CZ 3MZQFWfi+SWgvmG6Mv75oKtr4QHuocgfg+6B8zCkbTZf6ENFBVHyP1AKVZhLyg== Received: from SRVEX01-SZ.bfs.intern (10.129.90.31) by SRVEX01-SZ.bfs.intern (10.129.90.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2176.2; Tue, 9 Feb 2021 11:57:32 +0100 Received: from SRVEX01-SZ.bfs.intern ([fe80::7d2d:f9cb:2761:d24a]) by SRVEX01-SZ.bfs.intern ([fe80::7d2d:f9cb:2761:d24a%13]) with mapi id 15.01.2176.002; Tue, 9 Feb 2021 11:57:32 +0100 From: Walter Harms To: Dan Carpenter , Will Deacon Subject: AW: [PATCH][next] iommu/mediatek: Fix unsigned domid comparison with less than zero Thread-Topic: [PATCH][next] iommu/mediatek: Fix unsigned domid comparison with less than zero Thread-Index: AQHW+jVw6vQF7iLM7kGMzk6JKLJ0oqpHqk8AgAfZ0YCAACsEgg== Date: Tue, 9 Feb 2021 10:57:32 +0000 Message-ID: References: <20210203135936.23016-1-colin.king@canonical.com> <20210204092558.GA20244@willie-the-truck>,<20210209091923.GO2696@kadam> In-Reply-To: <20210209091923.GO2696@kadam> Accept-Language: de-DE, en-US Content-Language: de-DE X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.137.16.39] x-tm-as-product-ver: SMEX-14.0.0.3080-8.6.1012-25962.007 x-tm-as-result: No-10--7.431600-5.000000 x-tmase-matchedrid: qqoVTVjx6YDRubRCcrbc5grcxrzwsv5u3dCmvEa6IiHgYNP0+4v1nizy bVqWyY2NjrJzIoPQuMw+otRoIV3vSHVgBjkrax/H52zh+cq/0JuQBbTqDF++CmOMyb1Ixq8VUDG dbyXu/ma30GP8pin5GSKkzMT7+4ooN9rojbjxBkzXA3LnlKuVLMqFE6gRdROb+nlefiwGml8hlG 9iTcYtaqNIXC+Evb2D1qIE4CfpJ4zBm5Pnp+5TT/SG/+sPtZVkJih/yo+OvlXk6Qbi+9i6D0MmJ 6dGmSIy2JDeaNwtlNBVVkf0bJfBjyxppiUy9o4cGjzBgnFZvQ4vV5f7P0HVDETqq9Xa45y5XJvT MgAKYypb2hQcAFTn3WnsfYyMrTTf6Ne/nacGH0HM0ihsfYPMYdFTR6mnbN4LvGAx/1ATZ5sJetz 2R9zIsefqkkwronku/Sj/WnCM/LO/WXZS/HqJ2gtuKBGekqUpbGVEmIfjf3vt19sHZWTQhkfEDy E6wbBxQsEUiq7rfWGPfhLI9kH4wx7PLpUeWnT+ x-tm-as-user-approved-sender: No x-tm-as-user-blocked-sender: No x-tmase-result: 10--7.431600-5.000000 x-tmase-version: SMEX-14.0.0.3080-8.6.1012-25962.007 x-tm-snts-smtp: 8C502E7B3B6532B6AC707D8C4AE56DFF89CE4B2F07035BEC56FE6C2324B7857A2000:9 MIME-Version: 1.0 X-Spamd-Result: default: False [0.82 / 7.00]; ARC_NA(0.00)[]; TO_DN_EQ_ADDR_SOME(0.00)[]; HAS_XOIP(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; TO_MATCH_ENVRCPT_ALL(0.00)[]; TAGGED_RCPT(0.00)[]; MIME_GOOD(-0.10)[text/plain]; MID_RHS_MATCH_FROM(0.00)[]; DKIM_SIGNED(0.00)[bfs.de:s=dkim201901]; BAYES_HAM(-0.68)[83.00%]; RCPT_COUNT_TWELVE(0.00)[14]; NEURAL_HAM(-0.00)[-1.000]; RCVD_NO_TLS_LAST(0.10)[]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_CC(0.00)[canonical.com,8bytes.org,gmail.com,mediatek.com,chromium.org,lists.linux-foundation.org,lists.infradead.org,vger.kernel.org]; RCVD_COUNT_TWO(0.00)[2]; SUSPICIOUS_RECIPS(1.50)[] Authentication-Results: mx01-sz.bfs.de; none X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210209_055740_452408_CBBE6258 X-CRM114-Status: GOOD ( 20.95 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Anan sun , Joerg Roedel , "kernel-janitors@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Tomasz Figa , Chao Hao , "iommu@lists.linux-foundation.org" , "linux-mediatek@lists.infradead.org" , "linux-arm-kernel@lists.infradead.org" , Matthias Brugger , Colin King , Yong Wu Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org I second that ... Having i unsigned violates the rule of "least surprise". If you need it unsigned make it clearly visible, also adding a simple comment may help. jm2c, wh ________________________________________ Von: Dan Carpenter Gesendet: Dienstag, 9. Februar 2021 10:19:23 An: Will Deacon Cc: Colin King; Joerg Roedel; Matthias Brugger; Anan sun; Yong Wu; Chao Hao; Tomasz Figa; iommu@lists.linux-foundation.org; linux-arm-kernel@lists.infradead.org; linux-mediatek@lists.infradead.org; kernel-janitors@vger.kernel.org; linux-kernel@vger.kernel.org Betreff: Re: [PATCH][next] iommu/mediatek: Fix unsigned domid comparison with less than zero On Thu, Feb 04, 2021 at 09:25:58AM +0000, Will Deacon wrote: > On Wed, Feb 03, 2021 at 01:59:36PM +0000, Colin King wrote: > > From: Colin Ian King > > > > Currently the check for domid < 0 is always false because domid > > is unsigned. Fix this by making it signed. > > > > Addresses-CoverityL ("Unsigned comparison against 0") > > Typo here ('L' instead of ':') > > > Fixes: ab1d5281a62b ("iommu/mediatek: Add iova reserved function") > > Signed-off-by: Colin Ian King > > --- > > drivers/iommu/mtk_iommu.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > > index 0ad14a7604b1..823d719945b2 100644 > > --- a/drivers/iommu/mtk_iommu.c > > +++ b/drivers/iommu/mtk_iommu.c > > @@ -640,7 +640,7 @@ static void mtk_iommu_get_resv_regions(struct device *dev, > > struct list_head *head) > > { > > struct mtk_iommu_data *data = dev_iommu_priv_get(dev); > > - unsigned int domid = mtk_iommu_get_domain_id(dev, data->plat_data), i; > > + int domid = mtk_iommu_get_domain_id(dev, data->plat_data), i; > > Not sure if it's intentional, but this also makes 'i' signed. It probably > should remain 'unsigned' to match 'iova_region_nr' in > 'struct mtk_iommu_plat_data'. iova_region_nr is either 1 or 5 so unsigned doesn't matter. I once almost introduced a bug where the iterator was supposed to be size_t. I fixed a bug by making it signed but I ended up introducing a new bug. But generally that's pretty rare. The more common case is that making iterators unsigned introduces bugs. It's better to default to "int i;" and if more complicated types are required that should stand out. "size_t pg_idx;" or whatever. regards, dan carpenter _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel