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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68CD8C46467 for ; Mon, 16 Jan 2023 15:57:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231854AbjAPP5F (ORCPT ); Mon, 16 Jan 2023 10:57:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37504 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231644AbjAPP4n (ORCPT ); Mon, 16 Jan 2023 10:56:43 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2512023C46 for ; Mon, 16 Jan 2023 07:56:34 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 8FAE8B8105C for ; Mon, 16 Jan 2023 15:56:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D7153C433EF; Mon, 16 Jan 2023 15:56:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673884592; bh=G5EF7PpFZVglgHIPseKb+yxPqD94SmCDv24+S47++xM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Es/qzbvCyEouQWm9dkkYtrUKyk4Avbvo47CPXrMwiTXN3TmXtS/0J4eDNOdiI4UWQ cW2XwFsPMrM2ekizGBIhuG6AhIDvz/S/MdNeiUgFLM7OCdeZf9gyxRu+UbSTaYjtU9 To8FhE4m5YhpCCYr9fIvKF9d/AtqbdD9wDQEICfI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Denys Vlasenko , Liu Shixin , Pasha Tatashin , David Hildenbrand , Kefeng Wang , Will Deacon Subject: [PATCH 6.1 064/183] arm64/mm: fix incorrect file_map_count for invalid pmd Date: Mon, 16 Jan 2023 16:49:47 +0100 Message-Id: <20230116154806.047835359@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116154803.321528435@linuxfoundation.org> References: <20230116154803.321528435@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Liu Shixin commit 74c2f81054510d45b813548cb0a1c4ebf87cdd5f upstream. The page table check trigger BUG_ON() unexpectedly when split hugepage: ------------[ cut here ]------------ kernel BUG at mm/page_table_check.c:119! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 Hardware name: linux,dummy-virt (DT) pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : page_table_check_set.isra.0+0x398/0x468 lr : page_table_check_set.isra.0+0x1c0/0x468 [...] Call trace: page_table_check_set.isra.0+0x398/0x468 __page_table_check_pte_set+0x160/0x1c0 __split_huge_pmd_locked+0x900/0x1648 __split_huge_pmd+0x28c/0x3b8 unmap_page_range+0x428/0x858 unmap_single_vma+0xf4/0x1c8 zap_page_range+0x2b0/0x410 madvise_vma_behavior+0xc44/0xe78 do_madvise+0x280/0x698 __arm64_sys_madvise+0x90/0xe8 invoke_syscall.constprop.0+0xdc/0x1d8 do_el0_svc+0xf4/0x3f8 el0_svc+0x58/0x120 el0t_64_sync_handler+0xb8/0xc0 el0t_64_sync+0x19c/0x1a0 [...] On arm64, pmd_leaf() will return true even if the pmd is invalid due to pmd_present_invalid() check. So in pmdp_invalidate() the file_map_count will not only decrease once but also increase once. Then in set_pte_at(), the file_map_count increase again, and so trigger BUG_ON() unexpectedly. Add !pmd_present_invalid() check in pmd_user_accessible_page() to fix the problem. Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") Reported-by: Denys Vlasenko Signed-off-by: Liu Shixin Acked-by: Pasha Tatashin Acked-by: David Hildenbrand Reviewed-by: Kefeng Wang Acked-by: Will Deacon Link: https://lore.kernel.org/r/20221121073608.4183459-1-liushixin2@huawei.com Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/pgtable.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -863,7 +863,7 @@ static inline bool pte_user_accessible_p static inline bool pmd_user_accessible_page(pmd_t pmd) { - return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); + return pmd_leaf(pmd) && !pmd_present_invalid(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); } static inline bool pud_user_accessible_page(pud_t pud)