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 BB6D1C433EF for ; Thu, 24 Feb 2022 02:58:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230198AbiBXC7D (ORCPT ); Wed, 23 Feb 2022 21:59:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230189AbiBXC7D (ORCPT ); Wed, 23 Feb 2022 21:59:03 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 21A98B820B for ; Wed, 23 Feb 2022 18:58:34 -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 dfw.source.kernel.org (Postfix) with ESMTPS id AB724615C9 for ; Thu, 24 Feb 2022 02:58:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0CB3FC340E7; Thu, 24 Feb 2022 02:58:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1645671513; bh=sPnsXq5UK6bunG7cMKQ8cx9s5cpdoF+1DaHvJzKClMw=; h=Date:To:From:Subject:From; b=bw+ukh6VQOxfgJKwZ9FVNNC5Zwsw2aZBL2IYssASq8UEf69iZk2vBL6ynQG8d/tRq 1gzRGovochrhXKv/ROKyVhSOrwfrzTlQQVvU/T4/OdLsu6z/M4JekCoFlds4sVuOli ua2kAbVH+eYinxHipMhqVA1lQS6SHzKZSERdUvcU= Date: Wed, 23 Feb 2022 18:58:32 -0800 To: mm-commits@vger.kernel.org, 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@alien8.de, luofei@unicloud.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-hwpoison-avoid-the-impact-of-hwpoison_filter-return-value-on-mce-handler.patch added to -mm tree Message-Id: <20220224025833.0CB3FC340E7@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm/hwpoison: avoid the impact of hwpoison_filter() return value on mce handler has been added to the -mm tree. Its filename is mm-hwpoison-avoid-the-impact-of-hwpoison_filter-return-value-on-mce-handler.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-hwpoison-avoid-the-impact-of-hwpoison_filter-return-value-on-mce-handler.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-hwpoison-avoid-the-impact-of-hwpoison_filter-return-value-on-mce-handler.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ 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 value(-EHWPOISON), 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 a new MF_MCE_HANDLE flag is introduced to identify the call from the mce handler and instruct hwpoison_filter() to return -EHWPOISON, otherwise return 0 for compatibility with the hwpoison injector. Link: https://lkml.kernel.org/r/20220221021415.2328992-1-luofei@unicloud.com Signed-off-by: luofei Cc: 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 | 15 +++++++++------ include/linux/mm.h | 1 + mm/memory-failure.c | 14 ++++++++++++-- 3 files changed, 22 insertions(+), 8 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 @@ -612,7 +612,7 @@ static int uc_decode_notifier(struct not return NOTIFY_DONE; pfn = mce->addr >> PAGE_SHIFT; - if (!memory_failure(pfn, 0)) { + if (!memory_failure(pfn, MF_MCE_HANDLE)) { set_mce_nospec(pfn, whole_page(mce)); mce->kflags |= MCE_HANDLED_UC; } @@ -1286,7 +1286,7 @@ static void kill_me_now(struct callback_ static void kill_me_maybe(struct callback_head *cb) { struct task_struct *p = container_of(cb, struct task_struct, mce_kill_me); - int flags = MF_ACTION_REQUIRED; + int flags = MF_ACTION_REQUIRED | MF_MCE_HANDLE; int ret; p->mce_count = 0; @@ -1303,9 +1303,12 @@ 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. + * -EHWPOISON from memory_failure() means that memory_failure() did + * not handle the error event for the following reason: + * - SIGBUS has already been sent to the current process with the + * proper error info, or + * - hwpoison_filter() filtered the event, + * so no need to deal with it more. */ if (ret == -EHWPOISON) return; @@ -1320,7 +1323,7 @@ static void kill_me_never(struct callbac p->mce_count = 0; pr_err("Kernel accessed poison in user space at %llx\n", p->mce_addr); - if (!memory_failure(p->mce_addr >> PAGE_SHIFT, 0)) + if (!memory_failure(p->mce_addr >> PAGE_SHIFT, MF_MCE_HANDLE)) set_mce_nospec(p->mce_addr >> PAGE_SHIFT, p->mce_whole_page); } --- a/include/linux/mm.h~mm-hwpoison-avoid-the-impact-of-hwpoison_filter-return-value-on-mce-handler +++ a/include/linux/mm.h @@ -3177,6 +3177,7 @@ enum mf_flags { MF_MUST_KILL = 1 << 2, MF_SOFT_OFFLINE = 1 << 3, MF_UNPOISON = 1 << 4, + MF_MCE_HANDLE = 1 << 5, }; extern int memory_failure(unsigned long pfn, int flags); extern void memory_failure_queue(unsigned long pfn, int flags); --- 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 +1515,10 @@ static int memory_failure_hugetlb(unsign if (TestClearPageHWPoison(head)) num_poisoned_pages_dec(); unlock_page(head); - return 0; + if (flags & MF_MCE_HANDLE) + return -EHWPOISON; + else + return 0; } unlock_page(head); res = MF_FAILED; @@ -1602,7 +1605,10 @@ static int memory_failure_dev_pagemap(un goto out; if (hwpoison_filter(page)) { - rc = 0; + if (flags & MF_MCE_HANDLE) + rc = -EHWPOISON; + else + rc = 0; goto unlock; } @@ -1836,6 +1842,10 @@ try_again: num_poisoned_pages_dec(); unlock_page(p); put_page(p); + if (flags & MF_MCE_HANDLE) + res = -EHWPOISON; + else + res = 0; goto unlock_mutex; } _ Patches currently in -mm which might be from luofei@unicloud.com are mm-hwpoison-avoid-the-impact-of-hwpoison_filter-return-value-on-mce-handler.patch mm-hwpoison-add-in-use-hugepage-hwpoison-filter-judgement.patch