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=-13.4 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 7E7C1C433E2 for ; Tue, 1 Sep 2020 07:36:50 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2C9F5206CD for ; Tue, 1 Sep 2020 07:36:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="qAzX2egf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2C9F5206CD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id ABE076B0003; Tue, 1 Sep 2020 03:36:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A6D666B0037; Tue, 1 Sep 2020 03:36:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 95D336B0055; Tue, 1 Sep 2020 03:36:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0200.hostedemail.com [216.40.44.200]) by kanga.kvack.org (Postfix) with ESMTP id 7C5DF6B0003 for ; Tue, 1 Sep 2020 03:36:49 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 36C8B181AEF1A for ; Tue, 1 Sep 2020 07:36:49 +0000 (UTC) X-FDA: 77213685738.18.money30_36045a027096 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin18.hostedemail.com (Postfix) with ESMTP id 0F455100ED0F8 for ; Tue, 1 Sep 2020 07:36:49 +0000 (UTC) X-HE-Tag: money30_36045a027096 X-Filterd-Recvd-Size: 6591 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Tue, 1 Sep 2020 07:36:48 +0000 (UTC) Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0817XhAE175056; Tue, 1 Sep 2020 03:36:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=S1iFBELk1ZZ0IXFWXLknB8xFI5Dvn7zCRePqC6H6n0E=; b=qAzX2egf4bRqOSovcMdlhe+Klb9UcCF+mfetU5ELczRGOAonM1XPrKHpGCLkV/7ECnlb c0ZlWtAF0ekbod0dpingsaxLaomVnMZfuc+lTHOlVCTxJNRfO7mLH334CQELkLDa2nYg x/8zInckBZbXqZgRfsgXNIbAA9rDB1R8452kPbCx512HVVlr4tfG9ZNXFVUeopIPzOdu G7XvR+9hj4bDiePY69LQeLp29BQY8+uT1gkpfJOKcDUkG1rJy5LMnMApe0+q0BOXHSkY jwa4/US6NQ538GsRN33etEv4qYMWCut8/PC647aGGflyugse6pgWKMgmKXaYq1jWsqSR 9Q== 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 339gupa3ee-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 01 Sep 2020 03:36:37 -0400 Received: from pps.filterd (ppma03ams.nl.ibm.com [127.0.0.1]) by ppma03ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 0817XA8Z013173; Tue, 1 Sep 2020 07:36:34 GMT Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by ppma03ams.nl.ibm.com with ESMTP id 337en8b3x7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 01 Sep 2020 07:36:34 +0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 0817aWtp25559510 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 1 Sep 2020 07:36:32 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 98CFA11C052; Tue, 1 Sep 2020 07:36:32 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C20A911C04A; Tue, 1 Sep 2020 07:36:29 +0000 (GMT) Received: from [9.85.87.174] (unknown [9.85.87.174]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 1 Sep 2020 07:36:29 +0000 (GMT) Subject: Re: [PATCH v3 03/13] mm/debug_vm_pgtable/ppc64: Avoid setting top bits in radom value To: Anshuman Khandual , linux-mm@kvack.org, akpm@linux-foundation.org Cc: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linux-snps-arc@lists.infradead.org, x86@kernel.org, linux-arch@vger.kernel.org, Gerald Schaefer , Christophe Leroy , Vineet Gupta , Mike Rapoport , Qian Cai References: <20200827080438.315345-1-aneesh.kumar@linux.ibm.com> <20200827080438.315345-4-aneesh.kumar@linux.ibm.com> <3a0b0101-e6ec-26c5-e104-5b0bb95c3e51@arm.com> <1a8abe92-032b-f60f-1df1-52bb409b35a3@linux.ibm.com> <75771782-734b-69f6-4a07-2d3542458319@arm.com> From: "Aneesh Kumar K.V" Message-ID: Date: Tue, 1 Sep 2020 13:06:28 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <75771782-734b-69f6-4a07-2d3542458319@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-09-01_04:2020-09-01,2020-09-01 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 mlxlogscore=999 lowpriorityscore=0 priorityscore=1501 bulkscore=0 spamscore=0 mlxscore=0 malwarescore=0 phishscore=0 impostorscore=0 adultscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009010065 X-Rspamd-Queue-Id: 0F455100ED0F8 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 9/1/20 1:02 PM, Anshuman Khandual wrote: >=20 >=20 > On 09/01/2020 11:51 AM, Aneesh Kumar K.V wrote: >> On 9/1/20 8:45 AM, Anshuman Khandual wrote: >>> >>> >>> On 08/27/2020 01:34 PM, Aneesh Kumar K.V wrote: >>>> ppc64 use bit 62 to indicate a pte entry (_PAGE_PTE). Avoid setting = that bit in >>>> random value. >>>> >>>> Signed-off-by: Aneesh Kumar K.V >>>> --- >>>> =C2=A0 mm/debug_vm_pgtable.c | 13 ++++++++++--- >>>> =C2=A0 1 file changed, 10 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c >>>> index 086309fb9b6f..bbf9df0e64c6 100644 >>>> --- a/mm/debug_vm_pgtable.c >>>> +++ b/mm/debug_vm_pgtable.c >>>> @@ -44,10 +44,17 @@ >>>> =C2=A0=C2=A0 * entry type. But these bits might affect the ability = to clear entries with >>>> =C2=A0=C2=A0 * pxx_clear() because of how dynamic page table foldin= g works on s390. So >>>> =C2=A0=C2=A0 * while loading up the entries do not change the lower= 4 bits. It does not >>>> - * have affect any other platform. >>>> + * have affect any other platform. Also avoid the 62nd bit on ppc64= that is >>>> + * used to mark a pte entry. >>>> =C2=A0=C2=A0 */ >>>> -#define S390_MASK_BITS=C2=A0=C2=A0=C2=A0 4 >>>> -#define RANDOM_ORVALUE=C2=A0=C2=A0=C2=A0 GENMASK(BITS_PER_LONG - 1,= S390_MASK_BITS) >>>> +#define S390_SKIP_MASK=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 GE= NMASK(3, 0) >>>> +#ifdef CONFIG_PPC_BOOK3S_64 >>>> +#define PPC64_SKIP_MASK=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 G= ENMASK(62, 62) >>>> +#else >>>> +#define PPC64_SKIP_MASK=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 0= x0 >>>> +#endif >>> >>> Please drop the #ifdef CONFIG_PPC_BOOK3S_64 here. We already accommod= ate skip >>> bits for a s390 platform requirement and can also do so for ppc64 as = well. As >>> mentioned before, please avoid adding any platform specific construct= s in the >>> test. >>> >> >> >> that is needed so that it can be built on 32 bit architectures.I did f= ace build errors with arch-linux >=20 > Could not (#if __BITS_PER_LONG =3D=3D 32) be used instead or something = like > that. But should be a generic conditional check identifying 32 bit arch > not anything platform specific. >=20 that _PAGE_PTE bit is pretty much specific to PPC BOOK3S_64. Not sure=20 why other architectures need to bothered about ignoring bit 62. -aneesh