From nobody Wed Sep 17 14:14:16 2025 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 E91C0C77B75 for ; Mon, 8 May 2023 01:45:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232705AbjEHBpW (ORCPT ); Sun, 7 May 2023 21:45:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48716 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232596AbjEHBpK (ORCPT ); Sun, 7 May 2023 21:45:10 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 464171437F for ; Sun, 7 May 2023 18:45:01 -0700 (PDT) Received: from kwepemm600017.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4QF3tp09PtzLnwc; Mon, 8 May 2023 09:42:09 +0800 (CST) Received: from localhost.localdomain (10.175.112.125) by kwepemm600017.china.huawei.com (7.193.23.234) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Mon, 8 May 2023 09:44:57 +0800 From: Tong Tiangen To: Catalin Marinas , Mark Rutland , James Morse , Andrew Morton , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Robin Murphy , Dave Hansen , Will Deacon , Alexander Viro , , "H . Peter Anvin" CC: , , , Kefeng Wang , Guohanjun , Xie XiuQi , Tong Tiangen Subject: [PATCH -next v9 4/5] mm/hwpoison: return -EFAULT when copy fail in copy_mc_[user]_highpage() Date: Mon, 8 May 2023 09:44:35 +0800 Message-ID: <20230508014436.198717-5-tongtiangen@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230508014436.198717-1-tongtiangen@huawei.com> References: <20230508014436.198717-1-tongtiangen@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.112.125] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemm600017.china.huawei.com (7.193.23.234) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" If hardware errors are encountered during page copying, returning the bytes not copied is not meaningful, and the caller cannot do any processing on the remaining data. Returning -EFAULT is more reasonable, which represents a hardware error encountered during the copying. Signed-off-by: Tong Tiangen --- include/linux/highmem.h | 8 ++++---- mm/khugepaged.c | 4 ++-- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 4de1dbcd3ef6..c29f51ea8517 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -335,8 +335,8 @@ static inline void copy_highpage(struct page *to, struc= t page *from) /* * If architecture supports machine check exception handling, define the * #MC versions of copy_user_highpage and copy_highpage. They copy a memory - * page with #MC in source page (@from) handled, and return the number - * of bytes not copied if there was a #MC, otherwise 0 for success. + * page with #MC in source page (@from) handled, and return -EFAULT if the= re + * was a #MC, otherwise 0 for success. */ static inline int copy_mc_user_highpage(struct page *to, struct page *from, unsigned long vaddr, struct vm_area_struct *vma) @@ -352,7 +352,7 @@ static inline int copy_mc_user_highpage(struct page *to= , struct page *from, kunmap_local(vto); kunmap_local(vfrom); =20 - return ret; + return ret ? -EFAULT : 0; } =20 static inline int copy_mc_highpage(struct page *to, struct page *from) @@ -368,7 +368,7 @@ static inline int copy_mc_highpage(struct page *to, str= uct page *from) kunmap_local(vto); kunmap_local(vfrom); =20 - return ret; + return ret ? -EFAULT : 0; } #else static inline int copy_mc_user_highpage(struct page *to, struct page *from, diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 6b9d39d65b73..ef8b70377292 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -805,7 +805,7 @@ static int __collapse_huge_page_copy(pte_t *pte, continue; } src_page =3D pte_page(pteval); - if (copy_mc_user_highpage(page, src_page, _address, vma) > 0) { + if (copy_mc_user_highpage(page, src_page, _address, vma)) { result =3D SCAN_COPY_MC; break; } @@ -2140,7 +2140,7 @@ static int collapse_file(struct mm_struct *mm, unsign= ed long addr, clear_highpage(hpage + (index % HPAGE_PMD_NR)); index++; } - if (copy_mc_highpage(hpage + (page->index % HPAGE_PMD_NR), page) > 0) { + if (copy_mc_highpage(hpage + (page->index % HPAGE_PMD_NR), page)) { result =3D SCAN_COPY_MC; goto rollback; } --=20 2.25.1