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=-13.6 required=3.0 tests=BAYES_00, 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 36F9DC43461 for ; Tue, 1 Sep 2020 07:32:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DF4B3206CD for ; Tue, 1 Sep 2020 07:32:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DF4B3206CD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6D04B6B0037; Tue, 1 Sep 2020 03:32:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 681B16B0055; Tue, 1 Sep 2020 03:32:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 597C56B005A; Tue, 1 Sep 2020 03:32:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0175.hostedemail.com [216.40.44.175]) by kanga.kvack.org (Postfix) with ESMTP id 452146B0037 for ; Tue, 1 Sep 2020 03:32:43 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id F3544180AD806 for ; Tue, 1 Sep 2020 07:32:42 +0000 (UTC) X-FDA: 77213675406.26.brake75_32072f227096 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin26.hostedemail.com (Postfix) with ESMTP id C2FD91804B660 for ; Tue, 1 Sep 2020 07:32:42 +0000 (UTC) X-HE-Tag: brake75_32072f227096 X-Filterd-Recvd-Size: 3762 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Tue, 1 Sep 2020 07:32:42 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8002A1FB; Tue, 1 Sep 2020 00:32:41 -0700 (PDT) Received: from [10.163.69.134] (unknown [10.163.69.134]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3DFC33F71F; Tue, 1 Sep 2020 00:32:36 -0700 (PDT) From: Anshuman Khandual Subject: Re: [PATCH v3 03/13] mm/debug_vm_pgtable/ppc64: Avoid setting top bits in radom value To: "Aneesh Kumar K.V" , 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> Message-ID: <75771782-734b-69f6-4a07-2d3542458319@arm.com> Date: Tue, 1 Sep 2020 13:02:04 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <1a8abe92-032b-f60f-1df1-52bb409b35a3@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US X-Rspamd-Queue-Id: C2FD91804B660 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 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 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 t= hat 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 folding = 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 GEN= MASK(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 GE= NMASK(62, 62) >>> +#else >>> +#define PPC64_SKIP_MASK=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 0x= 0 >>> +#endif >> >> Please drop the #ifdef CONFIG_PPC_BOOK3S_64 here. We already accommoda= te skip >> bits for a s390 platform requirement and can also do so for ppc64 as w= ell. As >> mentioned before, please avoid adding any platform specific constructs= in the >> test. >> >=20 >=20 > that is needed so that it can be built on 32 bit architectures.I did fa= ce build errors with arch-linux Could not (#if __BITS_PER_LONG =3D=3D 32) be used instead or something li= ke that. But should be a generic conditional check identifying 32 bit arch not anything platform specific.