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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 1DCD0C10F13 for ; Thu, 11 Apr 2019 05:39:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E920A2133D for ; Thu, 11 Apr 2019 05:39:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726708AbfDKFj0 (ORCPT ); Thu, 11 Apr 2019 01:39:26 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:41768 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726090AbfDKFj0 (ORCPT ); Thu, 11 Apr 2019 01:39:26 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x3B5cWVf118687 for ; Thu, 11 Apr 2019 01:39:24 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2rswvym261-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 11 Apr 2019 01:39:24 -0400 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 11 Apr 2019 06:39:20 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x3B5dJ2945940816 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 11 Apr 2019 05:39:19 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5DC4552051; Thu, 11 Apr 2019 05:39:19 +0000 (GMT) Received: from skywalker.linux.ibm.com (unknown [9.85.73.26]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 01D085204E; Thu, 11 Apr 2019 05:39:17 +0000 (GMT) X-Mailer: emacs 26.1 (via feedmail 11-beta-1 I) From: "Aneesh Kumar K.V" To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH v1 01/27] powerpc/mm: Don't BUG() in hugepd_page() In-Reply-To: <9d6b0fe78346ff8e81a969a75a616bab59bc5cf5.1553076180.git.christophe.leroy@c-s.fr> References: <9d6b0fe78346ff8e81a969a75a616bab59bc5cf5.1553076180.git.christophe.leroy@c-s.fr> Date: Thu, 11 Apr 2019 11:09:15 +0530 MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-GCONF: 00 x-cbid: 19041105-0008-0000-0000-000002D894C8 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19041105-0009-0000-0000-00002244BB00 Message-Id: <87r2a93xto.fsf@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-04-11_04:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904110040 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christophe Leroy writes: > Don't BUG(), just warn and return NULL. > If the NULL value is not handled, it will get catched anyway. > > Signed-off-by: Christophe Leroy > --- > arch/powerpc/include/asm/hugetlb.h | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h > index 8d40565ad0c3..48c29686c78e 100644 > --- a/arch/powerpc/include/asm/hugetlb.h > +++ b/arch/powerpc/include/asm/hugetlb.h > @@ -14,7 +14,8 @@ > */ > static inline pte_t *hugepd_page(hugepd_t hpd) > { > - BUG_ON(!hugepd_ok(hpd)); > + if (WARN_ON(!hugepd_ok(hpd))) > + return NULL; We should not find that true. That BUG_ON was there to catch errors when changing pte formats. May be switch that VM_BUG_ON()? > /* > * We have only four bits to encode, MMU page size > */ > @@ -42,7 +43,8 @@ static inline void flush_hugetlb_page(struct vm_area_struct *vma, > > static inline pte_t *hugepd_page(hugepd_t hpd) > { > - BUG_ON(!hugepd_ok(hpd)); > + if (WARN_ON(!hugepd_ok(hpd))) > + return NULL; > #ifdef CONFIG_PPC_8xx > return (pte_t *)__va(hpd_val(hpd) & ~HUGEPD_SHIFT_MASK); > #else > -- > 2.13.3