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 522B8C43603 for ; Thu, 5 Dec 2019 14:32:08 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EB24624651 for ; Thu, 5 Dec 2019 14:32:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="g87e+2Nm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EB24624651 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 A0EF26B10A1; Thu, 5 Dec 2019 09:32:07 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9E64E6B10A3; Thu, 5 Dec 2019 09:32:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 922FF6B10A4; Thu, 5 Dec 2019 09:32:07 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0123.hostedemail.com [216.40.44.123]) by kanga.kvack.org (Postfix) with ESMTP id 7C74B6B10A1 for ; Thu, 5 Dec 2019 09:32:07 -0500 (EST) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 51D735DD7 for ; Thu, 5 Dec 2019 14:32:07 +0000 (UTC) X-FDA: 76231327494.09.mice39_2f85a58474d4c X-HE-Tag: mice39_2f85a58474d4c X-Filterd-Recvd-Size: 6188 Received: from mail-wm1-f67.google.com (mail-wm1-f67.google.com [209.85.128.67]) by imf12.hostedemail.com (Postfix) with ESMTP for ; Thu, 5 Dec 2019 14:32:06 +0000 (UTC) Received: by mail-wm1-f67.google.com with SMTP id f129so3947592wmf.2 for ; Thu, 05 Dec 2019 06:32:06 -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:content-transfer-encoding; bh=K+QNDo7OPu1vNuxsNHIsDrJtfW4QCEXpgqySPg6Gf5M=; b=g87e+2Nm2DAY1PYYq0vCVnoYtsL7542l6nggRViVK7MlPKV6Y5Fz2cmVmC5m7BDVI5 LMeoz/WCR6U/LZW+AnqiaYr8bXI9FmC2I2UK+Z1iZstN2EiAII9G61Y9mYDfmZvemVuJ l9wYXnWXSlONcvXd8/a56fAcXPcVNvwWpYc/d6qpHdSM3/NbIevRyXGTFeBFyow9WFSI mMcXHcxPKDKW0m3qEt9JSkmX8SWylHAajd699ShAbjRG6mJ0Lou3ZxKorV73HF8HHllA hI/giWPbTTNBL0v3hyTeOpmcMCfRo9qxpdhBSjDUI4lKvPvBZuLtXhDf4aF3VI+4m0x/ RYBA== 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:content-transfer-encoding; bh=K+QNDo7OPu1vNuxsNHIsDrJtfW4QCEXpgqySPg6Gf5M=; b=kyYXQrNeoyr7m8G396IqnWFBHIkIbhnh9hhheHRgFGHpQDSCvQqANFaxoirNoEXGXb BpJkzsMyBxlCQKHiJ+mWo9XwT91XVKDfHhXAl/I++0ZWhqugPgp0M8W3jy/yUU2St6k6 Y3DGJGG61PLxnO2lCt2cbUAFqY52uoeKwdrklPR9JHMS2rxOG8O7KNV62JTm2VB8Jl8s Bo26JjpGiu+6fzo5UUE9PiXeT+G2H7J7LdiWrKYsLzdWEhB5bDsu2eJah8L/lFGJoJGi QGM8e7U5WaFF/yDP9HabDZl18vC+haTZRAFhKebJXGEoW3mbU/ZHUqdLb0zXvrXLtl/Q AHBg== X-Gm-Message-State: APjAAAV/f4UFnJJcHVoZGqJnPSgm5+JON5B5OwlomV3IruVetm1oYKJ5 w0qhwUZ51k0DAvk9X9qWqPN+ypwzD/BPEgOWSbaPVw== X-Google-Smtp-Source: APXvYqz2YJ5l1GJBOsBnTcoWDYBK/Mzi07wrRSoYoWSKdbGDH2z2lHCFxyFmspUzrE1xTFKhQcteKyEkfpnBYH4pgW0= X-Received: by 2002:a7b:cb46:: with SMTP id v6mr5591723wmj.117.1575556325017; Thu, 05 Dec 2019 06:32:05 -0800 (PST) MIME-Version: 1.0 References: <20191122112621.204798-1-glider@google.com> <20191122112621.204798-36-glider@google.com> In-Reply-To: From: Alexander Potapenko Date: Thu, 5 Dec 2019 15:31:54 +0100 Message-ID: Subject: Re: [PATCH RFC v3 35/36] kmsan: ext4: skip block merging logic in ext4_mpage_readpages for KMSAN To: Marco Elver 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" 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 Tue, Dec 3, 2019 at 3:22 PM Marco Elver wrote: > > On Fri, 22 Nov 2019 at 12:28, wrote: > > > > KMSAN doesn't allow treating adjacent memory pages as such, if they wer= e > > allocated by different alloc_pages() calls. > > ext4_mpage_readpages() however does so: adjacent pages end up being pas= sed > > together to dma_direct_map_sg(). > > To prevent this, jump directly to the buffer_head-based read function i= n > > 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 *map= ping, > > if (page_has_buffers(page)) > > goto confused; > > > > +#if defined(CONFIG_KMSAN) > > Prefer 'if (IS_ENABLED(CONFIG_KMSAN))'. Done in v4. > Thanks, > -- Marco --=20 Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Stra=C3=9Fe, 33 80636 M=C3=BCnchen Gesch=C3=A4ftsf=C3=BChrer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg