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 EA2D0C432C0 for ; Tue, 3 Dec 2019 14:27:55 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A42B5206EC for ; Tue, 3 Dec 2019 14:27:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="vlfD9eLo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A42B5206EC 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 403806B055F; Tue, 3 Dec 2019 09:27:55 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3B4E46B0561; Tue, 3 Dec 2019 09:27:55 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 27C626B0562; Tue, 3 Dec 2019 09:27:55 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0167.hostedemail.com [216.40.44.167]) by kanga.kvack.org (Postfix) with ESMTP id 11FCD6B055F for ; Tue, 3 Dec 2019 09:27:55 -0500 (EST) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id C596C816B389 for ; Tue, 3 Dec 2019 14:27:54 +0000 (UTC) X-FDA: 76224059268.29.judge94_27e237824d63c X-HE-Tag: judge94_27e237824d63c X-Filterd-Recvd-Size: 6738 Received: from mail-wm1-f65.google.com (mail-wm1-f65.google.com [209.85.128.65]) by imf47.hostedemail.com (Postfix) with ESMTP for ; Tue, 3 Dec 2019 14:27:53 +0000 (UTC) Received: by mail-wm1-f65.google.com with SMTP id f4so2483361wmj.1 for ; Tue, 03 Dec 2019 06:27:53 -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=tdjEwSPg8H65ODNU8NoMG4RFmNmCRdTpQRLuTngch18=; b=vlfD9eLoJP5feF8otdJAOpd7mCpIvW8/xP2Bl6olw5ivWJXQawBMlRLz8dSzUEsjof kEdJM5+xE43FXCSXG/Zmou3Fa73Eh/QdDMorIOs+3nevtfhegZ9/w6nrNTRUZDWNxjmi QfYNiK2RppiFQnEmdy01tOs/vSm4CFO1tAgkpMblQ13lvCm9wxSwjHfyCcvna42rb1N5 EIgze4CU23cN1e5c+FUFr7Amb1gIH1QALYRWamaoSTsS5qJvQ+62gmGh2d27ZJ4vdk9U X9pl5VplTjk1zgm0SJpIIkd28CgdDoC/sXtyDrtxrLyKnq29wB379rCyyqs69+3M1Ceb dkNg== 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=tdjEwSPg8H65ODNU8NoMG4RFmNmCRdTpQRLuTngch18=; b=Ot9zNhqyu77QfOUYC0c8Wcc3/5O3irzYZ9dOtGNMSf+bufzVHwmcRgwLOv1MzDeNn5 NUBBtLOkXZ41qFKx0EvtcgICweU2HxtcDiPr9vn/lDZBNNIfA+l+CEjA81+wqWf9o5hm Iduxdmivk8QCL2khQfYhaCzvTtgeenPvi8bX0nAv06DKAo9lQR3kPycPkfT5orNpFl3F +jzI+/MqPwSWjgfMAd3VqkyD1lbgs4H8piQYGvuO78YJUYmHW/NNyVUfl0ylddGPfAkD 6oHn0NflBqvvoj8EVyzZRRC+AduBLrjB7iPyukwXn/y9zP9LjdK2qpVjtRQ50etL3vGB 7Xlw== X-Gm-Message-State: APjAAAXS2jmWZJu8GXbJM2en3Wr5T7bfx4e/uwn9jIUXgQuoyWjAqYW6 IMTtEAxOviXHkmeqiu6F+Qnf/CzG4p1rNdQzXIWgZg== X-Google-Smtp-Source: APXvYqxK8aJgmyYTkZumchSJwiF7x0RLTKu7e+9wN4d2MuxVsM5l1HrNT/MRj6XGLKj45kNXYBHaAOBmOCxQRbxTBgM= X-Received: by 2002:a1c:2e91:: with SMTP id u139mr29938204wmu.154.1575383272229; Tue, 03 Dec 2019 06:27:52 -0800 (PST) MIME-Version: 1.0 References: <20191122112621.204798-1-glider@google.com> <20191122112621.204798-12-glider@google.com> In-Reply-To: From: Alexander Potapenko Date: Tue, 3 Dec 2019 15:27:41 +0100 Message-ID: Subject: Re: [PATCH RFC v3 11/36] kmsan: stackdepot: don't allocate KMSAN metadata for stackdepot To: Andrey Konovalov Cc: Andrey Ryabinin , Jens Axboe , Andy Lutomirski , Vegard Nossum , Dmitry Vyukov , Christoph Hellwig , Linux Memory Management List , Alexander Viro , Andreas Dilger , Andrew Morton , Ard Biesheuvel , Arnd Bergmann , 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 , Marek Szyprowski , Marco Elver , 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 , "Theodore Ts'o" , 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: Archived-At: List-Archive: List-Post: On Fri, Nov 29, 2019 at 3:52 PM Andrey Konovalov wr= ote: > > On Fri, Nov 22, 2019 at 12:27 PM wrote: > > > > We assume nothing interesting could happen in stackdepot, and save some > > memory by not tracking stackdepot allocations with KMSAN. > > I think it makes sense to clarify here that "nothing interesting" > means no uninitialized memory can come from stackdepot or something > like that. Agreed. Will update the patch description. I've also noticed this patch does nothing to ensure the allocations are performed with __GFP_NO_KMSAN_SHADOW. > > > > Signed-off-by: Alexander Potapenko > > Cc: Andrey Ryabinin > > Cc: Jens Axboe > > Cc: Andy Lutomirski > > Cc: Vegard Nossum > > Cc: Dmitry Vyukov > > Cc: Christoph Hellwig > > Cc: linux-mm@kvack.org > > --- > > > > Change-Id: Ic3ec9b3dff3fff2732d874508a3582fb26ff0b1f > > --- > > lib/stackdepot.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/lib/stackdepot.c b/lib/stackdepot.c > > index e2f000a9fad8..2b053c429454 100644 > > --- a/lib/stackdepot.c > > +++ b/lib/stackdepot.c > > @@ -294,7 +294,8 @@ depot_stack_handle_t stack_depot_save(unsigned long= *entries, > > * contexts and I/O. > > */ > > alloc_flags &=3D ~GFP_ZONEMASK; > > - alloc_flags &=3D (GFP_ATOMIC | GFP_KERNEL); > > + alloc_flags &=3D (GFP_ATOMIC | GFP_KERNEL | > > + __GFP_NO_KMSAN_SHADOW); > > alloc_flags |=3D __GFP_NOWARN; Should have added __GFP_NO_KMSAN_SHADOW here. > > page =3D alloc_pages(alloc_flags, STACK_ALLOC_ORDER); > > if (page) > > -- > > 2.24.0.432.g9d3f5f5b63-goog > > --=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