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=-14.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 23125C432C0 for ; Tue, 3 Dec 2019 14:22:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DC9E620674 for ; Tue, 3 Dec 2019 14:22:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="DYPslnOW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DC9E620674 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 89CA86B055B; Tue, 3 Dec 2019 09:22:16 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 84D0E6B055C; Tue, 3 Dec 2019 09:22:16 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 78A276B055D; Tue, 3 Dec 2019 09:22:16 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0018.hostedemail.com [216.40.44.18]) by kanga.kvack.org (Postfix) with ESMTP id 624B76B055B for ; Tue, 3 Dec 2019 09:22:16 -0500 (EST) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 1C91B4DA3 for ; Tue, 3 Dec 2019 14:22:16 +0000 (UTC) X-FDA: 76224045072.11.form84_8829baebc5a5b X-HE-Tag: form84_8829baebc5a5b X-Filterd-Recvd-Size: 5558 Received: from mail-ot1-f67.google.com (mail-ot1-f67.google.com [209.85.210.67]) by imf30.hostedemail.com (Postfix) with ESMTP for ; Tue, 3 Dec 2019 14:22:15 +0000 (UTC) Received: by mail-ot1-f67.google.com with SMTP id a15so3063553otf.1 for ; Tue, 03 Dec 2019 06:22:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=kaChbH/dJiSbzHZTlnHz+i1HsMkAy9RjOflB4zpd0e4=; b=DYPslnOWrZLzqBHedOEIYvbbcuS1c6w+9V8RBhQFefSCTAj5d2KKFAdaowu+nQVQ6U fd4+pkLCg6OMZ4zKA3zT2CZEDboOFTBtGF/Vcn4PYW6/OE61w0Dmxy6LZCLst1NkroqQ 6ko0EEaAsGHvdbfNlth11zSxUKppUlmi9qFE6/BH2Nzyx5XTD72P9wCddbbNXoII5ELB 8w0Vk49jQlnnZ0XJImJUDn2voPUr5eenYB968gVxchGI1zlDvlusXBrFxkQOYHAIcjb7 mMv/rhX84jjBepQrYgAyI492Aa/CXtFQ3Big0MmYHoimc7aPqsLrjrMPEkvTZIYS2PSE JhwA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=kaChbH/dJiSbzHZTlnHz+i1HsMkAy9RjOflB4zpd0e4=; b=C7ZWNmkfGoqhkcHxcLbZyT4z63S2mZeVx704U/Ni/BBuj3SRcuK6YjtBEP/FrrsluT cdPcMOm3Rc6Xinxeq/J3rwY6hp6ScONNVDqI6eGeVSAxg85Ieav0ZsJBGWq4qiV97ceL 3ovkU+ekY2q/1tehb4bTZdzyczg1+pNYwhDNvhhhja8lV1kB5nFn52oZmUMJ0l95V+np WUIiXVuJHZ8jnmliLzHNVR2GxVPk/0WtLKBlh/Cx1QHTClLi0GtggHrllACzhGwozd3N xnK78LyQq9Hx+uDqpi3wvsg9SkO+1D/T2S3pnuqg68ah/77v05KVagqazdnukOy7wNGj 0yuw== X-Gm-Message-State: APjAAAXmq8FpKay02vnEm0O3/8N/OYEaQxv6imRMwrKLO3C2m41JYIIs iG+D6OoPjUPvJttaUWHZVR8yBTBko6+tFtBjTzuv1A== X-Google-Smtp-Source: APXvYqzuW46mnOmq1VvoydbmVgaodVJlrAOdVdW2/j6M64nnfr27fDLmyvaTtr4oge1SUqed6DU4ORPm0Zther3B6NM= X-Received: by 2002:a9d:588c:: with SMTP id x12mr3160213otg.2.1575382934511; Tue, 03 Dec 2019 06:22:14 -0800 (PST) MIME-Version: 1.0 References: <20191122112621.204798-1-glider@google.com> <20191122112621.204798-36-glider@google.com> In-Reply-To: <20191122112621.204798-36-glider@google.com> From: Marco Elver Date: Tue, 3 Dec 2019 15:22:03 +0100 Message-ID: Subject: Re: [PATCH RFC v3 35/36] kmsan: ext4: skip block merging logic in ext4_mpage_readpages for KMSAN To: Alexander Potapenko Cc: "Theodore Ts'o" , Andreas Dilger , Vegard Nossum , Dmitry Vyukov , Linux Memory Management List , Al Viro , Andrew Morton , Andrey Konovalov , Andrey Ryabinin , Andy Lutomirski , Ard Biesheuvel , Arnd Bergmann , Christoph Hellwig , Christoph Hellwig , "Darrick J. Wong" , "David S. Miller" , Dmitry Torokhov , Eric Biggers , Eric Dumazet , Eric Van Hensbergen , Greg Kroah-Hartman , Harry Wentland , Herbert Xu , Ilya Leoshkevich , Ingo Molnar , Jason Wang , Jens Axboe , Marek Szyprowski , Mark Rutland , "Martin K. Petersen" , Martin Schwidefsky , Matthew Wilcox , "Michael S. Tsirkin" , Michal Simek , Petr Mladek , Qian Cai , Randy Dunlap , Robin Murphy , Sergey Senozhatsky , Steven Rostedt , Takashi Iwai , Thomas Gleixner , Vasily Gorbik , Wolfram Sang Content-Type: text/plain; charset="UTF-8" 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 Fri, 22 Nov 2019 at 12:28, wrote: > > KMSAN doesn't allow treating adjacent memory pages as such, if they were > allocated by different alloc_pages() calls. > ext4_mpage_readpages() however does so: adjacent pages end up being passed > together to dma_direct_map_sg(). > To prevent this, jump directly to the buffer_head-based read function in > KMSAN builds. > > Signed-off-by: Alexander Potapenko > Cc: "Theodore Ts'o" > Cc: Andreas Dilger > Cc: Vegard Nossum > Cc: Dmitry Vyukov > Cc: linux-mm@kvack.org > --- > > Change-Id: I54ae8af536626a988e6398ff18a06c179b0ce034 > --- > fs/ext4/readpage.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c > index a30b203fa461..a3bb9e3ce5de 100644 > --- a/fs/ext4/readpage.c > +++ b/fs/ext4/readpage.c > @@ -252,6 +252,17 @@ int ext4_mpage_readpages(struct address_space *mapping, > if (page_has_buffers(page)) > goto confused; > > +#if defined(CONFIG_KMSAN) Prefer 'if (IS_ENABLED(CONFIG_KMSAN))'. Thanks, -- Marco