From patchwork Mon Feb 8 15:01:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 379111 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=-19.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 07994C4332D for ; Mon, 8 Feb 2021 15:37:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D05C764DFF for ; Mon, 8 Feb 2021 15:37:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233907AbhBHPhR (ORCPT ); Mon, 8 Feb 2021 10:37:17 -0500 Received: from mail.kernel.org ([198.145.29.99]:37210 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233967AbhBHPck (ORCPT ); Mon, 8 Feb 2021 10:32:40 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id A6C6A64ED1; Mon, 8 Feb 2021 15:18:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612797482; bh=KF6IruUkSfV1vancijK4inQAZPt5T+WJYyncJvY99pk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aUMzv6lxXPk/BGZHWqNbtGFzNISCgjsDnex3JLBdwjopXwYugf8RQhC9uNHdKvaPR erwGkzJA4sAJNSX4KVYKpoQCxu4vfqAMbw3I2Wm+UdQ7mECZhMIgN4gG44W3C1pje8 HmE1ufqXk3rHIWtmv74ARDGlsrhlRyLMqZTSczIo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Rokudo Yan , Mel Gorman , Vlastimil Babka , Andrew Morton , Linus Torvalds Subject: [PATCH 5.10 102/120] mm, compaction: move high_pfn to the for loop scope Date: Mon, 8 Feb 2021 16:01:29 +0100 Message-Id: <20210208145822.443206228@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210208145818.395353822@linuxfoundation.org> References: <20210208145818.395353822@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Rokudo Yan commit 74e21484e40bb8ce0f9828bbfe1c9fc9b04249c6 upstream. In fast_isolate_freepages, high_pfn will be used if a prefered one (ie PFN >= low_fn) not found. But the high_pfn is not reset before searching an free area, so when it was used as freepage, it may from another free area searched before. As a result move_freelist_head(freelist, freepage) will have unexpected behavior (eg corrupt the MOVABLE freelist) Unable to handle kernel paging request at virtual address dead000000000200 Mem abort info: ESR = 0x96000044 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000044 CM = 0, WnR = 1 [dead000000000200] address between user and kernel address ranges -000|list_cut_before(inline) -000|move_freelist_head(inline) -000|fast_isolate_freepages(inline) -000|isolate_freepages(inline) -000|compaction_alloc(?, ?) -001|unmap_and_move(inline) -001|migrate_pages([NSD:0xFFFFFF80088CBBD0] from = 0xFFFFFF80088CBD88, [NSD:0xFFFFFF80088CBBC8] get_new_p -002|__read_once_size(inline) -002|static_key_count(inline) -002|static_key_false(inline) -002|trace_mm_compaction_migratepages(inline) -002|compact_zone(?, [NSD:0xFFFFFF80088CBCB0] capc = 0x0) -003|kcompactd_do_work(inline) -003|kcompactd([X19] p = 0xFFFFFF93227FBC40) -004|kthread([X20] _create = 0xFFFFFFE1AFB26380) -005|ret_from_fork(asm) The issue was reported on an smart phone product with 6GB ram and 3GB zram as swap device. This patch fixes the issue by reset high_pfn before searching each free area, which ensure freepage and freelist match when call move_freelist_head in fast_isolate_freepages(). Link: http://lkml.kernel.org/r/20190118175136.31341-12-mgorman@techsingularity.net Link: https://lkml.kernel.org/r/20210112094720.1238444-1-wu-yan@tcl.com Fixes: 5a811889de10f1eb ("mm, compaction: use free lists to quickly locate a migration target") Signed-off-by: Rokudo Yan Acked-by: Mel Gorman Acked-by: Vlastimil Babka Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/compaction.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1302,7 +1302,7 @@ fast_isolate_freepages(struct compact_co { unsigned int limit = min(1U, freelist_scan_limit(cc) >> 1); unsigned int nr_scanned = 0; - unsigned long low_pfn, min_pfn, high_pfn = 0, highest = 0; + unsigned long low_pfn, min_pfn, highest = 0; unsigned long nr_isolated = 0; unsigned long distance; struct page *page = NULL; @@ -1347,6 +1347,7 @@ fast_isolate_freepages(struct compact_co struct page *freepage; unsigned long flags; unsigned int order_scanned = 0; + unsigned long high_pfn = 0; if (!area->nr_free) continue;