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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 30FFCC4332B for ; Wed, 18 Mar 2020 22:57:15 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DAA0320767 for ; Wed, 18 Mar 2020 22:57:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=intel-com.20150623.gappssmtp.com header.i=@intel-com.20150623.gappssmtp.com header.b="EklLyjkL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DAA0320767 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 838536B00B4; Wed, 18 Mar 2020 18:57:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7C11B6B00B5; Wed, 18 Mar 2020 18:57:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 689BB6B00B6; Wed, 18 Mar 2020 18:57:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0209.hostedemail.com [216.40.44.209]) by kanga.kvack.org (Postfix) with ESMTP id 4DF866B00B4 for ; Wed, 18 Mar 2020 18:57:14 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 035688248047 for ; Wed, 18 Mar 2020 22:57:14 +0000 (UTC) X-FDA: 76609995588.12.humor94_21fef6e851b5a X-HE-Tag: humor94_21fef6e851b5a X-Filterd-Recvd-Size: 3937 Received: from mail-oi1-f196.google.com (mail-oi1-f196.google.com [209.85.167.196]) by imf23.hostedemail.com (Postfix) with ESMTP for ; Wed, 18 Mar 2020 22:57:13 +0000 (UTC) Received: by mail-oi1-f196.google.com with SMTP id p125so619177oif.10 for ; Wed, 18 Mar 2020 15:57:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=502xfOTcGPvloOlOPOE6uSdUj6OdEwWuqCpfwx7ZYh8=; b=EklLyjkLxW/HbjZlQYKq10RHZGOYZa1lSYAXQzUU5hhctdTcwPGqmUJxfJOx0CMXfW x/bEu2dg+6iWJT05LrsCCIjqp7AlsJSI3S4DxKrN5YBbY4/VxOFFSzH6MVUI4QuoPMGt 6cApTkqmFn7miUtBIfD0P/7r4bcqbsq6+bl+JDYgNzzCERQ8lAVHQrBKM9hTxD4qmJka qQvMppbjiOu0SJYhcce9dLDPxtZcVl3sWm5v+dj8n+yJbzbUya66NGxkT8lEPoPkB4yC dedYmRQ4Aa3dpDAQprlIbBCF0ZfPveWD9KGBuh3TbqZQNtbQJ1xBsbUUQQeJu9ok/vlN XyUg== 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=502xfOTcGPvloOlOPOE6uSdUj6OdEwWuqCpfwx7ZYh8=; b=Bc3+pxWuqcaHaZWj7fgZ1pQvyJ7BnpdCFiLn3nRXQkMkKwkqK+eJ0YkwZDZqn1D85x spcDr1KRHiaW04Zk52BsSBsNGbWll8b0XkEUgIfP1g2AVgOL6ogWXq3SAqpoTubvKIbZ UogfgKZ5qQr7hQEQH3pbl/r3CkBCmHWHkzSUVm9liAoMuopzZdYp7rN9iaG2qIvVd3og h4D+OgflMaVFtuwl+fiPbv1gqC1UMb50V1Lhu2cxb85TWAY1Efy0TDnbgoThpYa9OZWD +4gBxTN6mlZizHLGIgquBZduBRn9bRiy7mGCDHAGge4BXv0SPxEjKSrWzpMGr3hpejob o4DQ== X-Gm-Message-State: ANhLgQ18lorZug5xaDMQPGWP7C1l5zYFJOzluQh3QHIlz9QcLW6/Tqx/ /2UiRCltMFLFWRNja09AvV8n0YHc7+7dzvNfjz3AOg== X-Google-Smtp-Source: ADFU+vt2n9SOt+QD04LJZnLkf3lWWw2V5wusFy6yaUclxTt8aREKpxuil86MbNlVqcwxKQdQdtjAXndR02uxaLmn8wg= X-Received: by 2002:a54:418a:: with SMTP id 10mr239833oiy.105.1584572232386; Wed, 18 Mar 2020 15:57:12 -0700 (PDT) MIME-Version: 1.0 References: <20200317135035.GA19442@SDF.ORG> <202003171435.41F7F0DF9@keescook> <20200317230612.GB19442@SDF.ORG> <202003171619.23210A7E0@keescook> <20200318014410.GA2281@SDF.ORG> <20200318203914.GA16083@SDF.ORG> <20200318224924.GC16083@SDF.ORG> In-Reply-To: <20200318224924.GC16083@SDF.ORG> From: Dan Williams Date: Wed, 18 Mar 2020 15:57:01 -0700 Message-ID: Subject: Re: [PATCH v3] mm/shuffle.c: Fix races in add_to_free_area_random() To: George Spelvin Cc: Alexander Duyck , Kees Cook , linux-mm , Andrew Morton , Randy Dunlap 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 Wed, Mar 18, 2020 at 3:49 PM George Spelvin wrote: > > On Wed, Mar 18, 2020 at 02:34:04PM -0700, Alexander Duyck wrote: > > What kernel is this based on? You might want to rebase on the latest > > linux-next as it occurs to me that this function was renamed to > > shuffle_pick_tail as I had incorporated a few bits of it into the > > logic for placing buddy pages and reported pages on the tail of the > > list. > > 5.5.8. I didn't realize it made much difference, but I see it does. Due > to the different return type, the best variant has probably changed and > I'll have to re-check. > > Since there's only one call site, should the function be moved to > page_alloc.c and inlined? The intent was to make it compile-away on CONFIG_SHUFFLE_PAGE_ALLOCATOR=n builds. However, CONFIG_SHUFFLE_PAGE_ALLOCATOR=y is now the common case for distros. So, it's not serving much purpose being in mm/shuffle.c. I'd support moving it.