From patchwork Mon Jun 23 19:40:47 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Micha=C5=82_Nazarewicz?= X-Patchwork-Id: 4404321 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 322019F387 for ; Mon, 23 Jun 2014 19:44:21 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 106CF202E9 for ; Mon, 23 Jun 2014 19:44:20 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1ADD2200E1 for ; Mon, 23 Jun 2014 19:44:19 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WzA7F-0006kW-VS; Mon, 23 Jun 2014 19:41:21 +0000 Received: from mail-wg0-x232.google.com ([2a00:1450:400c:c00::232]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WzA7C-0006hU-Gv for linux-arm-kernel@lists.infradead.org; Mon, 23 Jun 2014 19:41:19 +0000 Received: by mail-wg0-f50.google.com with SMTP id m15so126741wgh.9 for ; Mon, 23 Jun 2014 12:40:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=sender:from:to:cc:subject:in-reply-to:organization:references :user-agent:face:date:message-id:mime-version:content-type :content-transfer-encoding; bh=QL+B3L+ueKAxj4/uxz/jAaaehoopTb8ecoC2ohFT3J8=; b=Gp2JTy40VL3x2bMdedUG414TRVTUzqG1OX4F/R32aEI/CuDHPfPHzDGp/h5L4U0RGZ EmrpW+EE4yyWRmWMjzfJKPK3RPVzND4cTmcDqcGyG1JCfvFhyCDjOnp/Qps3EwdeiyOR z6tKYMjinT4cEBeCWUb0Ijr663wdnAO+1aiuYe4rxlmlNirNItqaO4AepdFUvfV/Y6e+ IdKDriW+9+dv/2+SiAwYvmFYiP/uxPIsX/sxGqYovxqi0rPsjPjSzWeaimmb731Ed2I4 1wxXOtKWXgmPfgHtqxHJOWQF+v0jlF/+oNNCythJ+2kcyBlGSJk8GZpQCW/L5dUfZeIJ aKKw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:sender:from:to:cc:subject:in-reply-to :organization:references:user-agent:face:date:message-id :mime-version:content-type:content-transfer-encoding; bh=QL+B3L+ueKAxj4/uxz/jAaaehoopTb8ecoC2ohFT3J8=; b=br6N7CwetGDlc+zvaI8eDgfpxY22mOn8KGIdLW0LQeWwvuNbkw60c3Y9f+pOEbYGnV qWsEa7noJZv2rMFkkUPgYCqBEcoELdCbHc/a3986GB4a3nEua+9oyHFW3gCSZ8+ZyBQM 9QgzIc9MYuPi8JiWlBFR8Uxf3otPcsWTRstFnJlR6B60n+WdjmfU9CAKtmY0ECyUgRM5 D+OKhVHPkzIZhKdlipjsWRRjz/S8XzTQ7wL0pnGXCBAkwIMxsFOmjHN7+JZM5t/7NUJ7 uI7Z3qjHtME0twQGugr8UPRoR3sH1iC0pa7p5p08gv2b9/RWbBnTIR+EKKk6i1BEP0p/ Wqxg== X-Gm-Message-State: ALoCoQltrUQuudEBbe3PMe/0/lkcSFDLFZoHEgj9IpMXEujaOy6aGasnjVefUGNh7zy6i2hpyMH2 X-Received: by 10.180.126.8 with SMTP id mu8mr29057627wib.10.1403552450761; Mon, 23 Jun 2014 12:40:50 -0700 (PDT) Received: from mpn-glaptop.roam.corp.google.com ([2620:0:105f:311:9dc5:7446:fde3:4b14]) by mx.google.com with ESMTPSA id am10sm38294163wjc.45.2014.06.23.12.40.49 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Mon, 23 Jun 2014 12:40:49 -0700 (PDT) From: Michal Nazarewicz To: Mark Salter Subject: [PATCHv3] mm: page_alloc: fix CMA area initialisation when pageblock > MAX_ORDER In-Reply-To: <1403285834.755.39.camel@deneb.redhat.com> Organization: http://mina86.com/ References: <1402522435-13884-1-git-send-email-msalter@redhat.com> <1403201524.32688.62.camel@deneb.redhat.com> <1403285834.755.39.camel@deneb.redhat.com> User-Agent: Notmuch/0.17+15~gb65ca8e (http://notmuchmail.org) Emacs/24.4.50.1 (x86_64-unknown-linux-gnu) X-Face: PbkBB1w#)bOqd`iCe"Ds{e+!C7`pkC9a|f)Qo^BMQvy\q5x3?vDQJeN(DS?|-^$uMti[3D*#^_Ts"pU$jBQLq~Ud6iNwAw_r_o_4]|JO?]}P_}Nc&"p#D(ZgUb4uCNPe7~a[DbPG0T~!&c.y$Ur,=N4RT>]dNpd; KFrfMCylc}gc??'U2j,!8%xdD Face: 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 X-PGP: 50751FF4 X-PGP-FP: AC1F 5F5C D418 88F8 CC84 5858 2060 4012 5075 1FF4 X-Hashcash: 1:20:140623:rientjes@google.com::VEwdXL/6J/yHCQxz:0000000000000000000000000000000000000000001BA3 X-Hashcash: 1:20:140623:linux-arm-kernel@lists.infradead.org::S5AY1H9JKI1caRT+:00000000000000000000000001a8X X-Hashcash: 1:20:140623:catalin.marinas@arm.com::cIbUpVMbRCElCi0E:000000000000000000000000000000000000002geg X-Hashcash: 1:20:140623:msalter@redhat.com::NRmP3aUyruLDsVgV:00000000000000000000000000000000000000000004Jfs X-Hashcash: 1:20:140623:linux-kernel@vger.kernel.org::LkCcWgfbGcmc8AnV:0000000000000000000000000000000004YeL X-Hashcash: 1:20:140623:m.szyprowski@samsung.com::PBJFOdlNM/AE8Rr+:0000000000000000000000000000000000000C2Xn Date: Mon, 23 Jun 2014 21:40:47 +0200 Message-ID: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140623_124118_877251_04ACFED5 X-CRM114-Status: GOOD ( 20.49 ) X-Spam-Score: -0.7 (/) Cc: Catalin Marinas , Marek Szyprowski , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, David Rientjes X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-1.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, T_DKIM_INVALID, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=no version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP With a kernel configured with ARM64_64K_PAGES && !TRANSPARENT_HUGEPAGE, the following is triggered at early boot: SMP: Total of 8 processors activated. devtmpfs: initialized Unable to handle kernel NULL pointer dereference at virtual address 00000008 pgd = fffffe0000050000 [00000008] *pgd=00000043fba00003, *pmd=00000043fba00003, *pte=00e0000078010407 Internal error: Oops: 96000006 [#1] SMP Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.15.0-rc864k+ #44 task: fffffe03bc040000 ti: fffffe03bc080000 task.ti: fffffe03bc080000 PC is at __list_add+0x10/0xd4 LR is at free_one_page+0x270/0x638 ... Call trace: [] __list_add+0x10/0xd4 [] free_one_page+0x26c/0x638 [] __free_pages_ok.part.52+0x84/0xbc [] __free_pages+0x74/0xbc [] init_cma_reserved_pageblock+0xe8/0x104 [] cma_init_reserved_areas+0x190/0x1e4 [] do_one_initcall+0xc4/0x154 [] kernel_init_freeable+0x204/0x2a8 [] kernel_init+0xc/0xd4 This happens because init_cma_reserved_pageblock() calls __free_one_page() with pageblock_order as page order but it is bigger han MAX_ORDER. This in turn causes accesses past zone->free_list[]. Fix the problem by changing init_cma_reserved_pageblock() such that it splits pageblock into individual MAX_ORDER pages if pageblock is bigger than a MAX_ORDER page. In cases where !CONFIG_HUGETLB_PAGE_SIZE_VARIABLE, which is all architectures expect for ia64, powerpc and tile at the moment, the “pageblock_order > MAX_ORDER” condition will be optimised out since both sides of the operator are constants. In cases where pageblock size is variable, the performance degradation should not be significant anyway since init_cma_reserved_pageblock() is called only at boot time at most MAX_CMA_AREAS times which by default is eight. Cc: stable@vger.kernel.org Signed-off-by: Michal Nazarewicz Reported-by: Mark Salter Tested-by: Christopher Covington --- mm/page_alloc.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) Mark Salter wrote: > I ended up needing this (on top of your patch) to get the system to > boot. Each MAX_ORDER-1 group needs the refcount and migratetype set > so that __free_pages does the right thing. > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 02fb1ed..a7ca6cc 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -799,17 +799,18 @@ void __init init_cma_reserved_pageblock(struct page *page) > set_page_count(p, 0); > } while (++p, --i); > > - set_page_refcounted(page); > - set_pageblock_migratetype(page, MIGRATE_CMA); > - > - if (pageblock_order > MAX_ORDER) { > - i = pageblock_order - MAX_ORDER; > + if (pageblock_order >= MAX_ORDER) { > + i = pageblock_order - MAX_ORDER + 1; > i = 1 << i; > p = page; > do { > - __free_pages(p, MAX_ORDER); > + set_page_refcounted(p); > + set_pageblock_migratetype(p, MIGRATE_CMA); > + __free_pages(p, MAX_ORDER - 1); > } while (p += MAX_ORDER_NR_PAGES, --i); > } else { > + set_page_refcounted(page); > + set_pageblock_migratetype(page, MIGRATE_CMA); > __free_pages(page, pageblock_order); > } This is kinda embarrassing, dunno how I missed that. But each page actually does not need to have migratetype set, does it? All of those pages are in a single pageblock so a single call suffices. If you track set_pageblock_migratetype down to pfn_to_bitidx there is: return (pfn >> pageblock_order) * NR_PAGEBLOCK_BITS; so for pfns inside of a pageblock, they get truncated. Or did I miss yet another thing? diff --git a/mm/page_alloc.c b/mm/page_alloc.c index ee92384..fef9614 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -816,9 +816,21 @@ void __init init_cma_reserved_pageblock(struct page *page) set_page_count(p, 0); } while (++p, --i); - set_page_refcounted(page); set_pageblock_migratetype(page, MIGRATE_CMA); - __free_pages(page, pageblock_order); + + if (pageblock_order >= MAX_ORDER) { + i = pageblock_nr_pages; + p = page; + do { + set_page_refcounted(p); + __free_pages(p, MAX_ORDER - 1); + p += MAX_ORDER_NR_PAGES; + } while (i -= MAX_ORDER_NR_PAGES); + } else { + set_page_refcounted(page); + __free_pages(page, pageblock_order); + } + adjust_managed_page_count(page, pageblock_nr_pages); } #endif