From mboxrd@z Thu Jan 1 00:00:00 1970 From: a.ryabinin@samsung.com (Andrey Ryabinin) Date: Fri, 17 Jul 2015 16:13:07 +0300 Subject: [PATCH v2 5/5] arm64: add KASan support In-Reply-To: <20150716160313.GC26865@e104818-lin.cambridge.arm.com> References: <1431698344-28054-1-git-send-email-a.ryabinin@samsung.com> <1431698344-28054-6-git-send-email-a.ryabinin@samsung.com> <20150708154803.GE6944@e104818-lin.cambridge.arm.com> <559FFCA7.4060008@samsung.com> <20150714150445.GH13555@e104818-lin.cambridge.arm.com> <55A61FF8.9000603@samsung.com> <20150715163732.GF20186@e104818-lin.cambridge.arm.com> <55A7CE03.301@samsung.com> <20150716160313.GC26865@e104818-lin.cambridge.arm.com> Message-ID: <55A8FF63.70505@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/16/2015 07:03 PM, Catalin Marinas wrote: > On Thu, Jul 16, 2015 at 06:30:11PM +0300, Andrey Ryabinin wrote: >> >> I think this may work, if pud_none(*pud) will be replaced with !pud_val(*pud). >> We can't use pud_none() because with 2-level page tables it's always false, so >> we will never go down to pmd level where swapper_pg_dir populated. > > The reason I used "do ... while" vs "while" or "for" is so that it gets > down to the pmd level. The iteration over pgd is always done in the top > loop via pgd_addr_end while the loops for missing levels (nopud, nopmd) > are always a single iteration whether we check for pud_none or not. But > when the level is present, we avoid looping when !pud_none(). > Right, dunno what I was thinking. It seems to work. Lightly tested with every possible CONFIG_PGTABLE_LEVELS. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f50.google.com (mail-pa0-f50.google.com [209.85.220.50]) by kanga.kvack.org (Postfix) with ESMTP id 42032280319 for ; Fri, 17 Jul 2015 09:13:19 -0400 (EDT) Received: by pacan13 with SMTP id an13so61151809pac.1 for ; Fri, 17 Jul 2015 06:13:19 -0700 (PDT) Received: from mailout2.w1.samsung.com (mailout2.w1.samsung.com. [210.118.77.12]) by mx.google.com with ESMTPS id xs3si18614351pbb.215.2015.07.17.06.13.17 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Fri, 17 Jul 2015 06:13:18 -0700 (PDT) Received: from eucpsbgm2.samsung.com (unknown [203.254.199.245]) by mailout2.w1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0NRM00CHIVE1Y080@mailout2.w1.samsung.com> for linux-mm@kvack.org; Fri, 17 Jul 2015 14:13:14 +0100 (BST) Message-id: <55A8FF63.70505@samsung.com> Date: Fri, 17 Jul 2015 16:13:07 +0300 From: Andrey Ryabinin MIME-version: 1.0 Subject: Re: [PATCH v2 5/5] arm64: add KASan support References: <1431698344-28054-1-git-send-email-a.ryabinin@samsung.com> <1431698344-28054-6-git-send-email-a.ryabinin@samsung.com> <20150708154803.GE6944@e104818-lin.cambridge.arm.com> <559FFCA7.4060008@samsung.com> <20150714150445.GH13555@e104818-lin.cambridge.arm.com> <55A61FF8.9000603@samsung.com> <20150715163732.GF20186@e104818-lin.cambridge.arm.com> <55A7CE03.301@samsung.com> <20150716160313.GC26865@e104818-lin.cambridge.arm.com> In-reply-to: <20150716160313.GC26865@e104818-lin.cambridge.arm.com> Content-type: text/plain; charset=windows-1252 Content-transfer-encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Catalin Marinas Cc: Arnd Bergmann , David Keitel , Will Deacon , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Alexander Potapenko , Dmitry Vyukov , Andrew Morton , linux-arm-kernel@lists.infradead.org On 07/16/2015 07:03 PM, Catalin Marinas wrote: > On Thu, Jul 16, 2015 at 06:30:11PM +0300, Andrey Ryabinin wrote: >> >> I think this may work, if pud_none(*pud) will be replaced with !pud_val(*pud). >> We can't use pud_none() because with 2-level page tables it's always false, so >> we will never go down to pmd level where swapper_pg_dir populated. > > The reason I used "do ... while" vs "while" or "for" is so that it gets > down to the pmd level. The iteration over pgd is always done in the top > loop via pgd_addr_end while the loops for missing levels (nopud, nopmd) > are always a single iteration whether we check for pud_none or not. But > when the level is present, we avoid looping when !pud_none(). > Right, dunno what I was thinking. It seems to work. Lightly tested with every possible CONFIG_PGTABLE_LEVELS. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758139AbbGQNNT (ORCPT ); Fri, 17 Jul 2015 09:13:19 -0400 Received: from mailout2.w1.samsung.com ([210.118.77.12]:33538 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758044AbbGQNNQ (ORCPT ); Fri, 17 Jul 2015 09:13:16 -0400 X-AuditID: cbfec7f5-f794b6d000001495-76-55a8ff69c2c9 Message-id: <55A8FF63.70505@samsung.com> Date: Fri, 17 Jul 2015 16:13:07 +0300 From: Andrey Ryabinin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-version: 1.0 To: Catalin Marinas Cc: Arnd Bergmann , David Keitel , Will Deacon , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Alexander Potapenko , Dmitry Vyukov , Andrew Morton , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 5/5] arm64: add KASan support References: <1431698344-28054-1-git-send-email-a.ryabinin@samsung.com> <1431698344-28054-6-git-send-email-a.ryabinin@samsung.com> <20150708154803.GE6944@e104818-lin.cambridge.arm.com> <559FFCA7.4060008@samsung.com> <20150714150445.GH13555@e104818-lin.cambridge.arm.com> <55A61FF8.9000603@samsung.com> <20150715163732.GF20186@e104818-lin.cambridge.arm.com> <55A7CE03.301@samsung.com> <20150716160313.GC26865@e104818-lin.cambridge.arm.com> In-reply-to: <20150716160313.GC26865@e104818-lin.cambridge.arm.com> Content-type: text/plain; charset=windows-1252 Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrGLMWRmVeSWpSXmKPExsVy+t/xy7qZ/1eEGry4qGwxZ/0aNou/k46x W7xf1sNosfvSM2aLCQ/b2C3aP+5lttj0+BqrxeVdc9gs7q35z2rx8uMJFgcujzXz1jB6/P41 idHjcl8vk8eCTaUemz5NYvc4MeM3i8fmJfUenzfJBXBEcdmkpOZklqUW6dslcGWsODqTveAM W8W5TVOZGxiXsXYxcnJICJhI/DzRxgJhi0lcuLeerYuRi0NIYCmjxI19O1khnO+MEtuWHQfK cHDwCmhITJvGBNLAIqAqMXvSbLBmNgE9iX+ztrOB2KICERJvL58Eq+EVEJT4MfkeWI2IgK7E hbYpLCAzmQUOM0mcbl/GDpIQBrriyfIl7BDLjjJLdB0HOY+Dg1PAWWLiCwEQkxlowf2LWiDl zALyEpvXvGWewCgwC8mKWQhVs5BULWBkXsUomlqaXFCclJ5rpFecmFtcmpeul5yfu4kREhtf dzAuPWZ1iFGAg1GJh7fBdUWoEGtiWXFl7iFGCQ5mJRHev9eAQrwpiZVVqUX58UWlOanFhxil OViUxHln7nofIiSQnliSmp2aWpBaBJNl4uCUamBUsUq7Hsmtnbvk7v+CXbzTfWaJdUe9n2/n ME+/fXNC3NXpwYZpcSxy+m+3cRVl/fv6h8ttT1Zv2ObuTSf2PoydEcH5d9tSyZdaPwOuim1Q eXXhwhdF/bBl56fFTNj3P1C9tOP1B5eZU9aKef1lrV16MSd9iV09555rLMGnZ6550c2/7+S2 x+calViKMxINtZiLihMBP49YgokCAAA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/16/2015 07:03 PM, Catalin Marinas wrote: > On Thu, Jul 16, 2015 at 06:30:11PM +0300, Andrey Ryabinin wrote: >> >> I think this may work, if pud_none(*pud) will be replaced with !pud_val(*pud). >> We can't use pud_none() because with 2-level page tables it's always false, so >> we will never go down to pmd level where swapper_pg_dir populated. > > The reason I used "do ... while" vs "while" or "for" is so that it gets > down to the pmd level. The iteration over pgd is always done in the top > loop via pgd_addr_end while the loops for missing levels (nopud, nopmd) > are always a single iteration whether we check for pud_none or not. But > when the level is present, we avoid looping when !pud_none(). > Right, dunno what I was thinking. It seems to work. Lightly tested with every possible CONFIG_PGTABLE_LEVELS.