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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97507C3DA4A for ; Fri, 9 Aug 2024 09:33:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 30D0D6B00A0; Fri, 9 Aug 2024 05:33:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 295AC6B00A2; Fri, 9 Aug 2024 05:33:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 10EFA6B00A3; Fri, 9 Aug 2024 05:33:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id E407E6B00A0 for ; Fri, 9 Aug 2024 05:33:11 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 546D8120B85 for ; Fri, 9 Aug 2024 09:33:11 +0000 (UTC) X-FDA: 82432193382.13.A4B92C6 Received: from mail-ej1-f48.google.com (mail-ej1-f48.google.com [209.85.218.48]) by imf12.hostedemail.com (Postfix) with ESMTP id 5508D40031 for ; Fri, 9 Aug 2024 09:33:09 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=suse.com header.s=google header.b=aDrzYIHC; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf12.hostedemail.com: domain of mhocko@suse.com designates 209.85.218.48 as permitted sender) smtp.mailfrom=mhocko@suse.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1723195935; a=rsa-sha256; cv=none; b=s0m5PHEnVOQMbi/CNbahj260bZUXDaaEgaQKzqNgXV5bDqGN8Gzdpo8FydE9D9CJAkaz3H REYpp8pn0YcZIlgVf0akq/LAi99OeACZycSGhqpes9406WcVNvxMyB675WbmLuBqNczK53 SNAnTrYqvIJrJwjyAlJC8xvA1P6yIas= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=suse.com header.s=google header.b=aDrzYIHC; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf12.hostedemail.com: domain of mhocko@suse.com designates 209.85.218.48 as permitted sender) smtp.mailfrom=mhocko@suse.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1723195935; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=YQ/7W0REmhBJNkhRjRfuyyIjuxfuImnqXUUGuD9v0J0=; b=y4kFAD54qiJmM6ggOMwdotdkBeCYveC/LqpKWzX6zuHD42SoK52kKwSRcZLFcah9Vm0k6y vAl8PlOcbbPBH/s+l/CGHF8AXX/RJusXYNXw3WMaTcH4zgwlRuHj6abrQLGOBnuNbvXRMK 6TDUJ7p5hE6X8fYGg90VyJojg60X3Fc= Received: by mail-ej1-f48.google.com with SMTP id a640c23a62f3a-a7d26c2297eso221674966b.2 for ; Fri, 09 Aug 2024 02:33:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1723195988; x=1723800788; darn=kvack.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=YQ/7W0REmhBJNkhRjRfuyyIjuxfuImnqXUUGuD9v0J0=; b=aDrzYIHCbEHiu/9CMFOJbX/QEf1Z4WGSP7CbHwql5UkTJlX4kLrrJzU/SM1k50b7CR uQ0Se/rfttoAtsVlLa3asOdU56aeOn2WKJEe8DN62bYleCUPI8D89opgbQlYTDu78r+O GmWs3kwokDaQPtNIg6SMQPWknbgLDXuSgdx7u5KHvp2FwbEpcrQk4kpWQSOOXnIRti7u OaQ7x2EMm/basDAEHuU/hl1VhFdqw+xtpYY4TjZmVW5rPPIqz3Zd0/mUjO8iMRWIbfjJ hhjnIN2NZzTQiY3DRwEzYKU0Gy7FoF9rl7zir1si0ft+1PFq623Cv26stlnm1/bnsl8e qlXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723195988; x=1723800788; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=YQ/7W0REmhBJNkhRjRfuyyIjuxfuImnqXUUGuD9v0J0=; b=ZlMIkOl5KbyiWaaKAwkK1BU9ZmQJkgy5c2OE5zRfUbz7I7LvPSrGPRmeOAzAYR3D84 iiTjcxVVL83RRcJ9/4YcTwMh6aZEa26tft3EJDaZTDMd1iYQ5n+eWsno8gZsedBv/WuK LcsrIvple4eFbOtiJ7XDTocs4Ze3/jT7v8Lsb+tqJAZoJGtSln7YMSQansEyQcG+seNw OS2s98jqUmiGebPfQCvnL5Ti532IRkIATl6rgoceTVwoNvtTGxFynwBJNFUQvxeh/xTX YI7XoxGKflYU3+YeabPHmN0dSLlG3IIKquORzQN7CXPIUx0bxBebQU/n3ayF11i9/bYL qNzw== X-Forwarded-Encrypted: i=1; AJvYcCUPmzb/wwxafSkFQ5EjDCwhi/KAjrUyNV3r7awIvVFb3XBc6qLafIZOHpOKfj1KiLZx6QTYH/7kga2nFu0HDBEa5pg= X-Gm-Message-State: AOJu0YyIuOJjwR9x3rRq0PbcSk30+pSZLzuAoB0NF1ZvTHaobZT8fNxJ iyrXuvYWWjrYmFVM1DFFQR8e52XnV8RS4ThhUfwj1LdhEAzjw0kUw2Fmu4lrwd0= X-Google-Smtp-Source: AGHT+IE9xexf/jaxgdOt406QdW0kF6zciEkqwtsHJEbToigyZHlPq0wpM1QjfdpTcmlCWSDpFwPaOA== X-Received: by 2002:a17:907:f19a:b0:a72:40b4:c845 with SMTP id a640c23a62f3a-a80aa65cffdmr86660366b.51.1723195987623; Fri, 09 Aug 2024 02:33:07 -0700 (PDT) Received: from localhost (109-81-83-166.rct.o2.cz. [109.81.83.166]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a7dc9bc3bd7sm824463666b.34.2024.08.09.02.33.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Aug 2024 02:33:07 -0700 (PDT) Date: Fri, 9 Aug 2024 11:33:06 +0200 From: Michal Hocko To: Barry Song <21cnbao@gmail.com> Cc: Hailong Liu , Andrew Morton , Uladzislau Rezki , Christoph Hellwig , Vlastimil Babka , Tangquan Zheng , stable@vger.kernel.org, Baoquan He , Matthew Wilcox , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RESEND PATCH v1] mm/vmalloc: fix page mapping if vm_area_alloc_pages() with high order fallback to order 0 Message-ID: References: <20240808122019.3361-1-hailong.liu@oppo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 5508D40031 X-Stat-Signature: qai51mcgt395fw9mkx4eakxec8ix5rod X-Rspam-User: X-HE-Tag: 1723195989-685070 X-HE-Meta: U2FsdGVkX1/iKzdhl2dvhzCr6v74QIxs5jQ1vD1MPUVXPUjH3rikDFBxEF5AKD+4sp2cgd6rUXrbNfVrUqrUmAs1iiR17fTZmdTkt2DjA3K+U/WjqJ1WaB7hRi0oARfHRwU+q0Q0d1RN4eEsyqoFMc353CTrbpmQC8kzwUnX60iCxdKb741bYrSJR9fX7pd3Z6+efps6RYOm2qpfhuQckQkkuSGxMOOtIOh/I1grQPtkUj4Su6uCOna/ZfgpWDvGyIZ41YnNfGsIUtRY/ozHWAcEtFM209wVsSa4C3oc76V/EOlHG965WTXUGO2pPT+WGOz8jRQRrewwkehyCyEp0v6wPRh70oDYLZSf63TRl8ajwCHMd8sL/kYXRwkccfaydav+wWKGdqdvI2lxOtF8gsXwM609jt4hdt2C+EExqwV/pjMETpcL8hyhkNBzHUGHLdINHmm1CNNBiXx54kj2V4cASoZDjqvoWz+99NNuFQqogGyIHrY6f69XTj3kx9SSET7pQuJ09QVPBI/BVQPzjqL2p+stNCyQL5HjU7IrSupC3dqKDZkEsuHCyrTcDircXmemng3kvq/bOHov/6JduFTRlIeLiwpij8vzVPd3UxM4xAB2OeSzLzF/4EPVx9M21iHm7MnSVBQV8XPefke2BJDSGJIAXDAPaz0nxTC+ijmk7BFAVUWZpC518oHGKaYDdiITkxAegHZCktGgkbnokX94n+mUwgl/4oeAgB3XpbYIESwZM9S/ZQ7qMQINhDS1T+M7J6AIFd1qvVOQ2TU2TQNcwGSrtLHElBaq9g9AE2mY60s1P8PzigcKg4woxzw/+IRkFuIPyG1zX3jFQRWoceotafzW6OHkdWvjl4xdNyDiDnvknV2ACn1NlB4GDX6bzlk/Z6tQobXPMwetehoQrLwVxHabmkUUcCYDoRI3XMYf2PgVU6DzJcT2ntqF8aXPEf2FCIXtgiuGqM50H5B w++E8Llq 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 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: List-Subscribe: List-Unsubscribe: On Fri 09-08-24 09:05:05, Barry Song wrote: > On Fri, Aug 9, 2024 at 12:20 AM Hailong Liu wrote: > > > > The __vmap_pages_range_noflush() assumes its argument pages** contains > > pages with the same page shift. However, since commit e9c3cda4d86e > > ("mm, vmalloc: fix high order __GFP_NOFAIL allocations"), if gfp_flags > > includes __GFP_NOFAIL with high order in vm_area_alloc_pages() > > and page allocation failed for high order, the pages** may contain > > two different page shifts (high order and order-0). This could > > lead __vmap_pages_range_noflush() to perform incorrect mappings, > > potentially resulting in memory corruption. > > > > Users might encounter this as follows (vmap_allow_huge = true, 2M is for PMD_SIZE): > > kvmalloc(2M, __GFP_NOFAIL|GFP_X) > > __vmalloc_node_range_noprof(vm_flags=VM_ALLOW_HUGE_VMAP) > > vm_area_alloc_pages(order=9) ---> order-9 allocation failed and fallback to order-0 > > vmap_pages_range() > > vmap_pages_range_noflush() > > __vmap_pages_range_noflush(page_shift = 21) ----> wrong mapping happens > > > > We can remove the fallback code because if a high-order > > allocation fails, __vmalloc_node_range_noprof() will retry with > > order-0. Therefore, it is unnecessary to fallback to order-0 > > here. Therefore, fix this by removing the fallback code. > > > > Fixes: e9c3cda4d86e ("mm, vmalloc: fix high order __GFP_NOFAIL allocations") > > Signed-off-by: Hailong Liu > > Reported-by: Tangquan Zheng > > Cc: > > CC: Barry Song <21cnbao@gmail.com> > > CC: Baoquan He > > CC: Matthew Wilcox > > --- > > Acked-by: Barry Song > > because we already have a fallback here: > > void *__vmalloc_node_range_noprof : > > fail: > if (shift > PAGE_SHIFT) { > shift = PAGE_SHIFT; > align = real_align; > size = real_size; > goto again; > } This really deserves a comment because this is not really clear at all. The code is also fragile and it would benefit from some re-org. Thanks for the fix. Acked-by: Michal Hocko -- Michal Hocko SUSE Labs