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=-15.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 BA1FDC4320E for ; Wed, 18 Aug 2021 14:32:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A10E8610A7 for ; Wed, 18 Aug 2021 14:32:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239124AbhHROdK (ORCPT ); Wed, 18 Aug 2021 10:33:10 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:44514 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238896AbhHROdG (ORCPT ); Wed, 18 Aug 2021 10:33:06 -0400 Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 17IE3Od0152425; Wed, 18 Aug 2021 10:31:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=date : from : to : cc : subject : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=pp1; bh=hINMW+W/5Ot3YR26bfaimyZQXNFx6687q4snjOgYREg=; b=NupYUEPg4k+woLQOQ6I9th5QpKHGlbN6WzpbJ2E59ZJrJAzu4vv3xD7XKgT5JIXDGNm1 Z2kBvwVpN/FuANZ824Qqvs8XgqgdYkxEekWxhG+tNMEhRqUmlnGsWClyNiRPfFTTfz1z mPBZxKm+OgIq10wN2cXDd97X3zktPlul0PElmyOEtlFS7xocoD4V4eum3yfO9K3HFM7h HF3EfK2i90w/u97kIOrotKfIzqRuUKD4L7IjUkcD8YpVPnoEIoTl4jCnkeVBWQW08oE6 c28GpOWkwEDhWAZV8tcOfIO0IW6nc8cOL7HZhtKeiPk4nu3G/7/2HEAdBPeWatTFgKXb tQ== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3agcvs7h6v-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 18 Aug 2021 10:31:51 -0400 Received: from m0187473.ppops.net (m0187473.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 17IE3QpR152705; Wed, 18 Aug 2021 10:31:50 -0400 Received: from ppma03ams.nl.ibm.com (62.31.33a9.ip4.static.sl-reverse.com [169.51.49.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 3agcvs7h42-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 18 Aug 2021 10:31:50 -0400 Received: from pps.filterd (ppma03ams.nl.ibm.com [127.0.0.1]) by ppma03ams.nl.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 17IEEK9h013108; Wed, 18 Aug 2021 14:31:47 GMT Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by ppma03ams.nl.ibm.com with ESMTP id 3ae5f8era4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 18 Aug 2021 14:31:47 +0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 17IEViFj49676594 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 18 Aug 2021 14:31:44 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E35C911C04A; Wed, 18 Aug 2021 14:31:43 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C845F11C05B; Wed, 18 Aug 2021 14:31:42 +0000 (GMT) Received: from p-imbrenda (unknown [9.145.14.177]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 18 Aug 2021 14:31:42 +0000 (GMT) Date: Wed, 18 Aug 2021 16:29:53 +0200 From: Claudio Imbrenda To: "Maciej S. Szmigiero" Cc: Paolo Bonzini , Vitaly Kuznetsov , Sean Christopherson , Wanpeng Li , Jim Mattson , Igor Mammedov , Marc Zyngier , James Morse , Julien Thierry , Suzuki K Poulose , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Christian Borntraeger , Janosch Frank , David Hildenbrand , Cornelia Huck , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 06/13] KVM: Move WARN on invalid memslot index to update_memslots() Message-ID: <20210818162953.225d6977@p-imbrenda> In-Reply-To: <8db0f1d1901768b5de1417caa425e62d1118e5e8.1628871413.git.maciej.szmigiero@oracle.com> References: <8db0f1d1901768b5de1417caa425e62d1118e5e8.1628871413.git.maciej.szmigiero@oracle.com> Organization: IBM X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: U3AdZ2vbFuvAj4jcJM1-s4IDztzLUZTv X-Proofpoint-GUID: 6hKUBKCcraXfYRKOa55yL0hGF64P5AsR X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.790 definitions=2021-08-18_04:2021-08-17,2021-08-18 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 clxscore=1015 suspectscore=0 mlxscore=0 mlxlogscore=999 phishscore=0 priorityscore=1501 malwarescore=0 impostorscore=0 bulkscore=0 adultscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2107140000 definitions=main-2108180089 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 13 Aug 2021 21:33:19 +0200 "Maciej S. Szmigiero" wrote: > From: "Maciej S. Szmigiero" > > Since kvm_memslot_move_forward() can theoretically return a negative > memslot index even when kvm_memslot_move_backward() returned a positive one > (and so did not WARN) let's just move the warning to the common code. > > Signed-off-by: Maciej S. Szmigiero Reviewed-by: Claudio Imbrenda > --- > virt/kvm/kvm_main.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 03ef42d2e421..7000efff1425 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -1293,8 +1293,7 @@ static inline int kvm_memslot_move_backward(struct kvm_memslots *slots, > struct kvm_memory_slot *mslots = slots->memslots; > int i; > > - if (WARN_ON_ONCE(slots->id_to_index[memslot->id] == -1) || > - WARN_ON_ONCE(!slots->used_slots)) > + if (slots->id_to_index[memslot->id] == -1 || !slots->used_slots) > return -1; > > /* > @@ -1398,6 +1397,9 @@ static void update_memslots(struct kvm_memslots *slots, > i = kvm_memslot_move_backward(slots, memslot); > i = kvm_memslot_move_forward(slots, memslot, i); > > + if (WARN_ON_ONCE(i < 0)) > + return; > + > /* > * Copy the memslot to its new position in memslots and update > * its index accordingly.