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 79393C432C0 for ; Fri, 29 Nov 2019 14:52:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3B43F215A5 for ; Fri, 29 Nov 2019 14:52:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="pjGKOUTT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B43F215A5 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 BAB386B0558; Fri, 29 Nov 2019 09:52:35 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B350C6B0596; Fri, 29 Nov 2019 09:52:35 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9FAD36B0597; Fri, 29 Nov 2019 09:52:35 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0200.hostedemail.com [216.40.44.200]) by kanga.kvack.org (Postfix) with ESMTP id 85E3C6B0558 for ; Fri, 29 Nov 2019 09:52:35 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 5E9E66109 for ; Fri, 29 Nov 2019 14:52:35 +0000 (UTC) X-FDA: 76209606270.23.plane14_1682bf1beee4a X-HE-Tag: plane14_1682bf1beee4a X-Filterd-Recvd-Size: 5724 Received: from mail-pj1-f66.google.com (mail-pj1-f66.google.com [209.85.216.66]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Fri, 29 Nov 2019 14:52:34 +0000 (UTC) Received: by mail-pj1-f66.google.com with SMTP id y21so13365968pjn.9 for ; Fri, 29 Nov 2019 06:52:34 -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=rjyL2VGR6W2NzKYIzNEua0H113xIOpJGTc8WOuH2vV0=; b=pjGKOUTTg3aue9zTeyvtMg5UMW9WPsLD7u1U5O5TUOpyLuBoM5OA0Hgl+JXnP+dtLc TDDcfY5qeEUNvZFqj4aoEI1uNgD9QEk4zydOtDY3TvlhLBswHtIei+0XInjt7uNAG6dl V0m/RcUyVYw74JGk4t2z6IoXRCdGUVF6E2XtKhnip2iODcIVOJ9MJbHIk7MUfJqc7ZzF z8F5jSrUYu0l8XW029OcK+dZkDQ4hmszZeXP1To/QMA2Ungejjsp2YrA/ZystzRlFun8 lY1EMHVbq5ocinura+krn8yESJYcZcIWqcAT1evU/KqUY86SeKTKMFNp8acZk8z5uQTB Sfqg== 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=rjyL2VGR6W2NzKYIzNEua0H113xIOpJGTc8WOuH2vV0=; b=MOGLfhIz6D+Ab+Y9G6dwjTOrdpgAAo21bXPMncsv7KHEaQScT7pXbefDUTQ5F7WPiC HalcZbiygBtuKYlHg4ytha3KYiOXMw7elRrrxyvclldYq4ZW2OrVa/c6nz5LLH7kUaW/ oiTNqKYaOIUrxBqG6I/D2aChdnkDn8cXT5BW4lSEryaX6ulpdboub8AvAw+YchnngmcV Md44UTe+R/oJw2xfIHAQqgpTVYhwm1cZkZGaDvUiJZFaSgm0vaO0vNdk0BsZHplImg94 HEaLi7h7JCJtE7glUBS2y0G4LrefSoS9U4p6NWd8MoDU0fkkQ1c2Jzkx2ajUk9bs1nQF o/Bg== X-Gm-Message-State: APjAAAWsu9OzTWD69SEYJl8+iRPibunWUR1GfyoNucit+Yxf+05iYUtV nJKPmRXvkTAawwmIonAVkErcAES9scbpnICv8G7mog== X-Google-Smtp-Source: APXvYqzTXli4YrOpUcP+c1Bk5x73XtsAQPdZw81dY3dwNW+6mGXZz/xZneXmQ7ZbdxfYBLXaCeW9n/quHdpnJj8QSdY= X-Received: by 2002:a17:90b:438b:: with SMTP id in11mr19230795pjb.129.1575039153198; Fri, 29 Nov 2019 06:52:33 -0800 (PST) MIME-Version: 1.0 References: <20191122112621.204798-1-glider@google.com> <20191122112621.204798-12-glider@google.com> In-Reply-To: <20191122112621.204798-12-glider@google.com> From: Andrey Konovalov Date: Fri, 29 Nov 2019 15:52:21 +0100 Message-ID: Subject: Re: [PATCH RFC v3 11/36] kmsan: stackdepot: don't allocate KMSAN metadata for stackdepot To: Alexander Potapenko 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.wong@oracle.com, "David S. Miller" , Dmitry Torokhov , ebiggers@google.com, Eric Dumazet , ericvh@gmail.com, Greg Kroah-Hartman , harry.wentland@amd.com, Herbert Xu , iii@linux.ibm.com, mingo@elte.hu, Jason Wang , Marek Szyprowski , Marco Elver , Mark Rutland , "Martin K. Petersen" , Martin Schwidefsky , Matthew Wilcox , "Michael S . Tsirkin" , Michal Simek , pmladek@suse.com, Qian Cai , Randy Dunlap , Robin Murphy , sergey.senozhatsky@gmail.com, Steven Rostedt , Takashi Iwai , "Theodore Ts'o" , Thomas Gleixner , gor@linux.ibm.com, wsa@the-dreams.de 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, 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. > > 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 &= ~GFP_ZONEMASK; > - alloc_flags &= (GFP_ATOMIC | GFP_KERNEL); > + alloc_flags &= (GFP_ATOMIC | GFP_KERNEL | > + __GFP_NO_KMSAN_SHADOW); > alloc_flags |= __GFP_NOWARN; > page = alloc_pages(alloc_flags, STACK_ALLOC_ORDER); > if (page) > -- > 2.24.0.432.g9d3f5f5b63-goog >