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 0E281C4321E for ; Tue, 22 Mar 2022 21:44:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230240AbiCVVqZ (ORCPT ); Tue, 22 Mar 2022 17:46:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236337AbiCVVqS (ORCPT ); Tue, 22 Mar 2022 17:46:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C7485F8F8 for ; Tue, 22 Mar 2022 14:44:40 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 369956119A for ; Tue, 22 Mar 2022 21:44:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8DC27C340EC; Tue, 22 Mar 2022 21:44:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1647985479; bh=ZvOSrd3ZmpmUC3b9SxlsCcPdesA004qet5FVbPnbosk=; h=Date:To:From:In-Reply-To:Subject:From; b=IuUJKBgQSK/bDVYL2hGQn9my63DEkCF/dugsqgLIpL//0vhd5oIqmEPvBIEhYNO+a wBUvUPT/JEJSdEVdyX1ZNYP0R5GEahHBjN+el7UEvFu1MXBvTqV++AJ/GJuiS1fCf8 bq+oSvrWNayjGZ35fuztoUg8gsDNJQOaf+wiEdIM= Date: Tue, 22 Mar 2022 14:44:38 -0700 To: tony.luck@intel.com, tglx@linutronix.de, naoya.horiguchi@nec.com, mingo@redhat.com, linmiaohe@huawei.com, hpa@zytor.com, dave.hansen@linux.intel.com, bp@suse.de, luofei@unicloud.com, akpm@linux-foundation.org, patches@lists.linux.dev, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org From: Andrew Morton In-Reply-To: <20220322143803.04a5e59a07e48284f196a2f9@linux-foundation.org> Subject: [patch 121/227] mm/hwpoison: avoid the impact of hwpoison_filter() return value on mce handler Message-Id: <20220322214439.8DC27C340EC@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: luofei Subject: mm/hwpoison: avoid the impact of hwpoison_filter() return value on mce handler When the hwpoison page meets the filter conditions, it should not be regarded as successful memory_failure() processing for mce handler, but should return a distinct value, otherwise mce handler regards the error page has been identified and isolated, which may lead to calling set_mce_nospec() to change page attribute, etc. Here memory_failure() return -EOPNOTSUPP to indicate that the error event is filtered, mce handler should not take any action for this situation and hwpoison injector should treat as correct. Link: https://lkml.kernel.org/r/20220223082135.2769649-1-luofei@unicloud.com Signed-off-by: luofei Acked-by: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Miaohe Lin Cc: Naoya Horiguchi Cc: Thomas Gleixner Cc: Tony Luck Signed-off-by: Andrew Morton --- arch/x86/kernel/cpu/mce/core.c | 8 +++++--- drivers/base/memory.c | 2 ++ mm/hwpoison-inject.c | 3 ++- mm/madvise.c | 2 ++ mm/memory-failure.c | 9 +++++++-- 5 files changed, 18 insertions(+), 6 deletions(-) --- a/arch/x86/kernel/cpu/mce/core.c~mm-hwpoison-avoid-the-impact-of-hwpoison_filter-return-value-on-mce-handler +++ a/arch/x86/kernel/cpu/mce/core.c @@ -1304,10 +1304,12 @@ static void kill_me_maybe(struct callbac /* * -EHWPOISON from memory_failure() means that it already sent SIGBUS - * to the current process with the proper error info, so no need to - * send SIGBUS here again. + * to the current process with the proper error info, + * -EOPNOTSUPP means hwpoison_filter() filtered the error event, + * + * In both cases, no further processing is required. */ - if (ret == -EHWPOISON) + if (ret == -EHWPOISON || ret == -EOPNOTSUPP) return; pr_err("Memory error not recovered"); --- a/drivers/base/memory.c~mm-hwpoison-avoid-the-impact-of-hwpoison_filter-return-value-on-mce-handler +++ a/drivers/base/memory.c @@ -555,6 +555,8 @@ static ssize_t hard_offline_page_store(s return -EINVAL; pfn >>= PAGE_SHIFT; ret = memory_failure(pfn, 0); + if (ret == -EOPNOTSUPP) + ret = 0; return ret ? ret : count; } --- a/mm/hwpoison-inject.c~mm-hwpoison-avoid-the-impact-of-hwpoison_filter-return-value-on-mce-handler +++ a/mm/hwpoison-inject.c @@ -48,7 +48,8 @@ static int hwpoison_inject(void *data, u inject: pr_info("Injecting memory failure at pfn %#lx\n", pfn); - return memory_failure(pfn, 0); + err = memory_failure(pfn, 0); + return (err == -EOPNOTSUPP) ? 0 : err; } static int hwpoison_unpoison(void *data, u64 val) --- a/mm/madvise.c~mm-hwpoison-avoid-the-impact-of-hwpoison_filter-return-value-on-mce-handler +++ a/mm/madvise.c @@ -1067,6 +1067,8 @@ static int madvise_inject_error(int beha pr_info("Injecting memory failure for pfn %#lx at process virtual address %#lx\n", pfn, start); ret = memory_failure(pfn, MF_COUNT_INCREASED); + if (ret == -EOPNOTSUPP) + ret = 0; } if (ret) --- a/mm/memory-failure.c~mm-hwpoison-avoid-the-impact-of-hwpoison_filter-return-value-on-mce-handler +++ a/mm/memory-failure.c @@ -1515,7 +1515,7 @@ static int memory_failure_hugetlb(unsign if (TestClearPageHWPoison(head)) num_poisoned_pages_dec(); unlock_page(head); - return 0; + return -EOPNOTSUPP; } unlock_page(head); res = MF_FAILED; @@ -1602,7 +1602,7 @@ static int memory_failure_dev_pagemap(un goto out; if (hwpoison_filter(page)) { - rc = 0; + rc = -EOPNOTSUPP; goto unlock; } @@ -1671,6 +1671,10 @@ static DEFINE_MUTEX(mf_mutex); * * Must run in process context (e.g. a work queue) with interrupts * enabled and no spinlocks hold. + * + * Return: 0 for successfully handled the memory error, + * -EOPNOTSUPP for memory_filter() filtered the error event, + * < 0(except -EOPNOTSUPP) on failure. */ int memory_failure(unsigned long pfn, int flags) { @@ -1836,6 +1840,7 @@ try_again: num_poisoned_pages_dec(); unlock_page(p); put_page(p); + res = -EOPNOTSUPP; goto unlock_mutex; } _