From nobody Wed Sep 17 12:02:21 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 16064C7EE2C for ; Mon, 8 May 2023 01:45:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232615AbjEHBpD (ORCPT ); Sun, 7 May 2023 21:45:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232542AbjEHBo6 (ORCPT ); Sun, 7 May 2023 21:44:58 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35CF612093 for ; Sun, 7 May 2023 18:44:57 -0700 (PDT) Received: from kwepemm600017.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4QF3vr6r9rzsR5p; Mon, 8 May 2023 09:43:04 +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 09:44:53 +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 1/5] uaccess: add generic fallback version of copy_mc_to_user() Date: Mon, 8 May 2023 09:44:32 +0800 Message-ID: <20230508014436.198717-2-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" x86/powerpc has it's implementation of copy_mc_to_user(), we add generic fallback in include/linux/uaccess.h prepare for other architechures to enable CONFIG_ARCH_HAS_COPY_MC. Signed-off-by: Tong Tiangen Acked-by: Michael Ellerman --- arch/powerpc/include/asm/uaccess.h | 1 + arch/x86/include/asm/uaccess.h | 1 + include/linux/uaccess.h | 9 +++++++++ 3 files changed, 11 insertions(+) diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/= uaccess.h index a2d255aa9627..1713dff36568 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -381,6 +381,7 @@ copy_mc_to_user(void __user *to, const void *from, unsi= gned long n) =20 return n; } +#define copy_mc_to_user copy_mc_to_user #endif =20 extern long __copy_from_user_flushcache(void *dst, const void __user *src, diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 457e814712af..37d3c078d768 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -573,6 +573,7 @@ copy_mc_to_kernel(void *to, const void *from, unsigned = len); =20 unsigned long __must_check copy_mc_to_user(void *to, const void *from, unsigned len); +#define copy_mc_to_user copy_mc_to_user #endif =20 /* diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 3064314f4832..550287c92990 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -205,6 +205,15 @@ copy_mc_to_kernel(void *dst, const void *src, size_t c= nt) } #endif =20 +#ifndef copy_mc_to_user +static inline unsigned long __must_check +copy_mc_to_user(void *dst, const void *src, size_t cnt) +{ + check_object_size(src, cnt, true); + return raw_copy_to_user(dst, src, cnt); +} +#endif + static __always_inline void pagefault_disabled_inc(void) { current->pagefault_disabled++; --=20 2.25.1 From nobody Wed Sep 17 12:02:21 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 DB38DC77B7D for ; Mon, 8 May 2023 01:45:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232635AbjEHBpO (ORCPT ); Sun, 7 May 2023 21:45:14 -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 S232624AbjEHBpG (ORCPT ); Sun, 7 May 2023 21:45:06 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC0281387E for ; Sun, 7 May 2023 18:44:58 -0700 (PDT) Received: from kwepemm600017.china.huawei.com (unknown [172.30.72.55]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4QF3sD5MZFz18KyN; Mon, 8 May 2023 09:40:48 +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 09:44:55 +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 2/5] arm64: add support for machine check error safe Date: Mon, 8 May 2023 09:44:33 +0800 Message-ID: <20230508014436.198717-3-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" For the arm64 kernel, when it processes hardware memory errors for synchronize notifications(do_sea()), if the errors is consumed within the kernel, the current processing is panic. However, it is not optimal. Take uaccess for example, if the uaccess operation fails due to memory error, only the user process will be affected. Killing the user process and isolating the corrupt page is a better choice. This patch only enable machine error check framework and adds an exception fixup before the kernel panic in do_sea(). Signed-off-by: Tong Tiangen --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/extable.h | 1 + arch/arm64/mm/extable.c | 16 ++++++++++++++++ arch/arm64/mm/fault.c | 29 ++++++++++++++++++++++++++++- 4 files changed, 46 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index b1201d25a8a4..730b815acfca 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -20,6 +20,7 @@ config ARM64 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE select ARCH_HAS_CACHE_LINE_SIZE + select ARCH_HAS_COPY_MC if ACPI_APEI_GHES select ARCH_HAS_CURRENT_STACK_POINTER select ARCH_HAS_DEBUG_VIRTUAL select ARCH_HAS_DEBUG_VM_PGTABLE diff --git a/arch/arm64/include/asm/extable.h b/arch/arm64/include/asm/exta= ble.h index 72b0e71cc3de..f80ebd0addfd 100644 --- a/arch/arm64/include/asm/extable.h +++ b/arch/arm64/include/asm/extable.h @@ -46,4 +46,5 @@ bool ex_handler_bpf(const struct exception_table_entry *e= x, #endif /* !CONFIG_BPF_JIT */ =20 bool fixup_exception(struct pt_regs *regs); +bool fixup_exception_mc(struct pt_regs *regs); #endif diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c index 228d681a8715..478e639f8680 100644 --- a/arch/arm64/mm/extable.c +++ b/arch/arm64/mm/extable.c @@ -76,3 +76,19 @@ bool fixup_exception(struct pt_regs *regs) =20 BUG(); } + +bool fixup_exception_mc(struct pt_regs *regs) +{ + const struct exception_table_entry *ex; + + ex =3D search_exception_tables(instruction_pointer(regs)); + if (!ex) + return false; + + /* + * This is not complete, More Machine check safe extable type can + * be processed here. + */ + + return false; +} diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 9e0db5c387e3..4d490d820f1a 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -749,6 +749,31 @@ static int do_bad(unsigned long far, unsigned long esr= , struct pt_regs *regs) return 1; /* "fault" */ } =20 +static bool arm64_do_kernel_sea(unsigned long addr, unsigned int esr, + struct pt_regs *regs, int sig, int code) +{ + if (!IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC)) + return false; + + if (user_mode(regs)) + return false; + + if (apei_claim_sea(regs) < 0) + return false; + + if (!fixup_exception_mc(regs)) + return false; + + if (current->flags & PF_KTHREAD) + return true; + + set_thread_esr(0, esr); + arm64_force_sig_fault(sig, code, addr, + "Uncorrected memory error on access to user memory\n"); + + return true; +} + static int do_sea(unsigned long far, unsigned long esr, struct pt_regs *re= gs) { const struct fault_info *inf; @@ -774,7 +799,9 @@ static int do_sea(unsigned long far, unsigned long esr,= struct pt_regs *regs) */ siaddr =3D untagged_addr(far); } - arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr); + + if (!arm64_do_kernel_sea(siaddr, esr, regs, inf->sig, inf->code)) + arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr); =20 return 0; } --=20 2.25.1 From nobody Wed Sep 17 12:02:21 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 EB7A0C77B75 for ; Mon, 8 May 2023 01:45:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232655AbjEHBpR (ORCPT ); Sun, 7 May 2023 21:45:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232580AbjEHBpG (ORCPT ); Sun, 7 May 2023 21:45:06 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C016911D89 for ; Sun, 7 May 2023 18:44:59 -0700 (PDT) Received: from kwepemm600017.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4QF3sF2GZSzpTRk; Mon, 8 May 2023 09:40:49 +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 09:44:56 +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 3/5] arm64: add uaccess to machine check safe Date: Mon, 8 May 2023 09:44:34 +0800 Message-ID: <20230508014436.198717-4-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 user process access memory fails due to hardware memory error, only the relevant processes are affected, so it is more reasonable to kill the user process and isolate the corrupt page than to panic the kernel. Signed-off-by: Tong Tiangen --- arch/arm64/mm/extable.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c index 478e639f8680..28ec35e3d210 100644 --- a/arch/arm64/mm/extable.c +++ b/arch/arm64/mm/extable.c @@ -85,10 +85,10 @@ bool fixup_exception_mc(struct pt_regs *regs) if (!ex) return false; =20 - /* - * This is not complete, More Machine check safe extable type can - * be processed here. - */ + switch (ex->type) { + case EX_TYPE_UACCESS_ERR_ZERO: + return ex_handler_uaccess_err_zero(ex, regs); + } =20 return false; } --=20 2.25.1 From nobody Wed Sep 17 12:02:21 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 From nobody Wed Sep 17 12:02:21 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 8C126C7EE22 for ; Mon, 8 May 2023 01:45:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232735AbjEHBpZ (ORCPT ); Sun, 7 May 2023 21:45:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232625AbjEHBpM (ORCPT ); Sun, 7 May 2023 21:45:12 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F22E156A6 for ; Sun, 7 May 2023 18:45:03 -0700 (PDT) Received: from kwepemm600017.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4QF3rp0czMzTk2V; Mon, 8 May 2023 09:40:26 +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 09:44:59 +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 5/5] arm64: support copy_mc_[user]_highpage() Date: Mon, 8 May 2023 09:44:36 +0800 Message-ID: <20230508014436.198717-6-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" Currently, many scenarios that can tolerate memory errors when copying page have been supported in the kernel[1][2][3], all of which are implemented by copy_mc_[user]_highpage(). arm64 should also support this mechanism. Due to mte, arm64 needs to have its own copy_mc_[user]_highpage() architecture implementation, macros __HAVE_ARCH_COPY_MC_HIGHPAGE and __HAVE_ARCH_COPY_MC_USER_HIGHPAGE have been added to control it. Add new helper copy_mc_page() which provide a page copy implementation with machine check safe. The copy_mc_page() in copy_mc_page.S is largely borrows from copy_page() in copy_page.S and the main difference is copy_mc_page() add extable entry to every load/store insn to support machine check safe. Add new extable type EX_TYPE_COPY_MC_PAGE_ERR_ZERO which used in copy_mc_page(). [1]a873dfe1032a ("mm, hwpoison: try to recover from copy-on write faults") [2]5f2500b93cc9 ("mm/khugepaged: recover from poisoned anonymous memory") [3]6b970599e807 ("mm: hwpoison: support recovery from ksm_might_need_to_cop= y()") Signed-off-by: Tong Tiangen --- arch/arm64/include/asm/asm-extable.h | 15 +++++ arch/arm64/include/asm/assembler.h | 4 ++ arch/arm64/include/asm/mte.h | 5 ++ arch/arm64/include/asm/page.h | 10 ++++ arch/arm64/lib/Makefile | 2 + arch/arm64/lib/copy_mc_page.S | 89 ++++++++++++++++++++++++++++ arch/arm64/lib/mte.S | 27 +++++++++ arch/arm64/mm/copypage.c | 64 +++++++++++++++++--- arch/arm64/mm/extable.c | 7 ++- include/linux/highmem.h | 4 ++ 10 files changed, 217 insertions(+), 10 deletions(-) create mode 100644 arch/arm64/lib/copy_mc_page.S diff --git a/arch/arm64/include/asm/asm-extable.h b/arch/arm64/include/asm/= asm-extable.h index 980d1dd8e1a3..819044fefbe7 100644 --- a/arch/arm64/include/asm/asm-extable.h +++ b/arch/arm64/include/asm/asm-extable.h @@ -10,6 +10,7 @@ #define EX_TYPE_UACCESS_ERR_ZERO 2 #define EX_TYPE_KACCESS_ERR_ZERO 3 #define EX_TYPE_LOAD_UNALIGNED_ZEROPAD 4 +#define EX_TYPE_COPY_MC_PAGE_ERR_ZERO 5 =20 /* Data fields for EX_TYPE_UACCESS_ERR_ZERO */ #define EX_DATA_REG_ERR_SHIFT 0 @@ -51,6 +52,16 @@ #define _ASM_EXTABLE_UACCESS(insn, fixup) \ _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, wzr, wzr) =20 +#define _ASM_EXTABLE_COPY_MC_PAGE_ERR_ZERO(insn, fixup, err, zero) \ + __ASM_EXTABLE_RAW(insn, fixup, \ + EX_TYPE_COPY_MC_PAGE_ERR_ZERO, \ + ( \ + EX_DATA_REG(ERR, err) | \ + EX_DATA_REG(ZERO, zero) \ + )) + +#define _ASM_EXTABLE_COPY_MC_PAGE(insn, fixup) \ + _ASM_EXTABLE_COPY_MC_PAGE_ERR_ZERO(insn, fixup, wzr, wzr) /* * Create an exception table entry for uaccess `insn`, which will branch t= o `fixup` * when an unhandled fault is taken. @@ -59,6 +70,10 @@ _ASM_EXTABLE_UACCESS(\insn, \fixup) .endm =20 + .macro _asm_extable_copy_mc_page, insn, fixup + _ASM_EXTABLE_COPY_MC_PAGE(\insn, \fixup) + .endm + /* * Create an exception table entry for `insn` if `fixup` is provided. Othe= rwise * do nothing. diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/as= sembler.h index 376a980f2bad..547ab2f85888 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -154,6 +154,10 @@ lr .req x30 // link register #define CPU_LE(code...) code #endif =20 +#define CPY_MC(l, x...) \ +9999: x; \ + _asm_extable_copy_mc_page 9999b, l + /* * Define a macro that constructs a 64-bit value by concatenating two * 32-bit registers. Note that on big endian systems the order of the diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h index c028afb1cd0b..df00d4aa226a 100644 --- a/arch/arm64/include/asm/mte.h +++ b/arch/arm64/include/asm/mte.h @@ -92,6 +92,7 @@ static inline bool try_page_mte_tagging(struct page *page) void mte_zero_clear_page_tags(void *addr); void mte_sync_tags(pte_t old_pte, pte_t pte); void mte_copy_page_tags(void *kto, const void *kfrom); +int mte_copy_mc_page_tags(void *kto, const void *kfrom); void mte_thread_init_user(void); void mte_thread_switch(struct task_struct *next); void mte_cpu_setup(void); @@ -128,6 +129,10 @@ static inline void mte_sync_tags(pte_t old_pte, pte_t = pte) static inline void mte_copy_page_tags(void *kto, const void *kfrom) { } +static inline int mte_copy_mc_page_tags(void *kto, const void *kfrom) +{ + return 0; +} static inline void mte_thread_init_user(void) { } diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h index 2312e6ee595f..304cc86b8a10 100644 --- a/arch/arm64/include/asm/page.h +++ b/arch/arm64/include/asm/page.h @@ -29,6 +29,16 @@ void copy_user_highpage(struct page *to, struct page *fr= om, void copy_highpage(struct page *to, struct page *from); #define __HAVE_ARCH_COPY_HIGHPAGE =20 +#ifdef CONFIG_ARCH_HAS_COPY_MC +int copy_mc_page(void *to, const void *from); +int copy_mc_highpage(struct page *to, struct page *from); +#define __HAVE_ARCH_COPY_MC_HIGHPAGE + +int copy_mc_user_highpage(struct page *to, struct page *from, + unsigned long vaddr, struct vm_area_struct *vma); +#define __HAVE_ARCH_COPY_MC_USER_HIGHPAGE +#endif + struct folio *vma_alloc_zeroed_movable_folio(struct vm_area_struct *vma, unsigned long vaddr); #define vma_alloc_zeroed_movable_folio vma_alloc_zeroed_movable_folio diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile index 29490be2546b..a2fd865b816d 100644 --- a/arch/arm64/lib/Makefile +++ b/arch/arm64/lib/Makefile @@ -15,6 +15,8 @@ endif =20 lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) +=3D uaccess_flushcache.o =20 +lib-$(CONFIG_ARCH_HAS_COPY_MC) +=3D copy_mc_page.o + obj-$(CONFIG_CRC32) +=3D crc32.o =20 obj-$(CONFIG_FUNCTION_ERROR_INJECTION) +=3D error-inject.o diff --git a/arch/arm64/lib/copy_mc_page.S b/arch/arm64/lib/copy_mc_page.S new file mode 100644 index 000000000000..656d831ef4b8 --- /dev/null +++ b/arch/arm64/lib/copy_mc_page.S @@ -0,0 +1,89 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2012 ARM Ltd. + */ + +#include +#include +#include +#include +#include +#include +#include + +/* + * Copy a page from src to dest (both are page aligned) with machine check + * + * Parameters: + * x0 - dest + * x1 - src + * Returns: + * x0 - Return 0 if copy success, or -EFAULT if anything goes wrong + * while copying. + */ +SYM_FUNC_START(__pi_copy_mc_page) +alternative_if ARM64_HAS_NO_HW_PREFETCH + // Prefetch three cache lines ahead. + prfm pldl1strm, [x1, #128] + prfm pldl1strm, [x1, #256] + prfm pldl1strm, [x1, #384] +alternative_else_nop_endif + +CPY_MC(9998f, ldp x2, x3, [x1]) +CPY_MC(9998f, ldp x4, x5, [x1, #16]) +CPY_MC(9998f, ldp x6, x7, [x1, #32]) +CPY_MC(9998f, ldp x8, x9, [x1, #48]) +CPY_MC(9998f, ldp x10, x11, [x1, #64]) +CPY_MC(9998f, ldp x12, x13, [x1, #80]) +CPY_MC(9998f, ldp x14, x15, [x1, #96]) +CPY_MC(9998f, ldp x16, x17, [x1, #112]) + + add x0, x0, #256 + add x1, x1, #128 +1: + tst x0, #(PAGE_SIZE - 1) + +alternative_if ARM64_HAS_NO_HW_PREFETCH + prfm pldl1strm, [x1, #384] +alternative_else_nop_endif + +CPY_MC(9998f, stnp x2, x3, [x0, #-256]) +CPY_MC(9998f, ldp x2, x3, [x1]) +CPY_MC(9998f, stnp x4, x5, [x0, #16 - 256]) +CPY_MC(9998f, ldp x4, x5, [x1, #16]) +CPY_MC(9998f, stnp x6, x7, [x0, #32 - 256]) +CPY_MC(9998f, ldp x6, x7, [x1, #32]) +CPY_MC(9998f, stnp x8, x9, [x0, #48 - 256]) +CPY_MC(9998f, ldp x8, x9, [x1, #48]) +CPY_MC(9998f, stnp x10, x11, [x0, #64 - 256]) +CPY_MC(9998f, ldp x10, x11, [x1, #64]) +CPY_MC(9998f, stnp x12, x13, [x0, #80 - 256]) +CPY_MC(9998f, ldp x12, x13, [x1, #80]) +CPY_MC(9998f, stnp x14, x15, [x0, #96 - 256]) +CPY_MC(9998f, ldp x14, x15, [x1, #96]) +CPY_MC(9998f, stnp x16, x17, [x0, #112 - 256]) +CPY_MC(9998f, ldp x16, x17, [x1, #112]) + + add x0, x0, #128 + add x1, x1, #128 + + b.ne 1b + +CPY_MC(9998f, stnp x2, x3, [x0, #-256]) +CPY_MC(9998f, stnp x4, x5, [x0, #16 - 256]) +CPY_MC(9998f, stnp x6, x7, [x0, #32 - 256]) +CPY_MC(9998f, stnp x8, x9, [x0, #48 - 256]) +CPY_MC(9998f, stnp x10, x11, [x0, #64 - 256]) +CPY_MC(9998f, stnp x12, x13, [x0, #80 - 256]) +CPY_MC(9998f, stnp x14, x15, [x0, #96 - 256]) +CPY_MC(9998f, stnp x16, x17, [x0, #112 - 256]) + + mov x0, #0 + ret + +9998: mov x0, #-EFAULT + ret + +SYM_FUNC_END(__pi_copy_mc_page) +SYM_FUNC_ALIAS(copy_mc_page, __pi_copy_mc_page) +EXPORT_SYMBOL(copy_mc_page) diff --git a/arch/arm64/lib/mte.S b/arch/arm64/lib/mte.S index 5018ac03b6bf..2b748e83f6cf 100644 --- a/arch/arm64/lib/mte.S +++ b/arch/arm64/lib/mte.S @@ -80,6 +80,33 @@ SYM_FUNC_START(mte_copy_page_tags) ret SYM_FUNC_END(mte_copy_page_tags) =20 +/* + * Copy the tags from the source page to the destination one wiht machine = check safe + * x0 - address of the destination page + * x1 - address of the source page + * Returns: + * x0 - Return 0 if copy success, or + * -EFAULT if anything goes wrong while copying. + */ +SYM_FUNC_START(mte_copy_mc_page_tags) + mov x2, x0 + mov x3, x1 + multitag_transfer_size x5, x6 +1: +CPY_MC(2f, ldgm x4, [x3]) +CPY_MC(2f, stgm x4, [x2]) + add x2, x2, x5 + add x3, x3, x5 + tst x2, #(PAGE_SIZE - 1) + b.ne 1b + + mov x0, #0 + ret + +2: mov x0, #-EFAULT + ret +SYM_FUNC_END(mte_copy_mc_page_tags) + /* * Read tags from a user buffer (one tag per byte) and set the correspondi= ng * tags at the given kernel address. Used by PTRACE_POKEMTETAGS. diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c index 4aadcfb01754..7cbc12ee6009 100644 --- a/arch/arm64/mm/copypage.c +++ b/arch/arm64/mm/copypage.c @@ -14,21 +14,34 @@ #include #include =20 -void copy_highpage(struct page *to, struct page *from) +static int do_mte(struct page *to, struct page *from, void *kto, void *kfr= om, bool mc) { - void *kto =3D page_address(to); - void *kfrom =3D page_address(from); - - copy_page(kto, kfrom); + int ret =3D 0; =20 if (system_supports_mte() && page_mte_tagged(from)) { if (kasan_hw_tags_enabled()) page_kasan_tag_reset(to); /* It's a new page, shouldn't have been tagged yet */ WARN_ON_ONCE(!try_page_mte_tagging(to)); - mte_copy_page_tags(kto, kfrom); - set_page_mte_tagged(to); + if (mc) + ret =3D mte_copy_mc_page_tags(kto, kfrom); + else + mte_copy_page_tags(kto, kfrom); + + if (!ret) + set_page_mte_tagged(to); } + + return ret; +} + +void copy_highpage(struct page *to, struct page *from) +{ + void *kto =3D page_address(to); + void *kfrom =3D page_address(from); + + copy_page(kto, kfrom); + do_mte(to, from, kto, kfrom, false); } EXPORT_SYMBOL(copy_highpage); =20 @@ -39,3 +52,40 @@ void copy_user_highpage(struct page *to, struct page *fr= om, flush_dcache_page(to); } EXPORT_SYMBOL_GPL(copy_user_highpage); + +#ifdef CONFIG_ARCH_HAS_COPY_MC +/* + * Return -EFAULT if anything goes wrong while copying page or mte. + */ +int copy_mc_highpage(struct page *to, struct page *from) +{ + void *kto =3D page_address(to); + void *kfrom =3D page_address(from); + int ret; + + ret =3D copy_mc_page(kto, kfrom); + if (ret) + return -EFAULT; + + ret =3D do_mte(to, from, kto, kfrom, true); + if (ret) + return -EFAULT; + + return 0; +} +EXPORT_SYMBOL(copy_mc_highpage); + +int copy_mc_user_highpage(struct page *to, struct page *from, + unsigned long vaddr, struct vm_area_struct *vma) +{ + int ret; + + ret =3D copy_mc_highpage(to, from); + + if (!ret) + flush_dcache_page(to); + + return ret; +} +EXPORT_SYMBOL_GPL(copy_mc_user_highpage); +#endif diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c index 28ec35e3d210..bdc81518d207 100644 --- a/arch/arm64/mm/extable.c +++ b/arch/arm64/mm/extable.c @@ -16,7 +16,7 @@ get_ex_fixup(const struct exception_table_entry *ex) return ((unsigned long)&ex->fixup + ex->fixup); } =20 -static bool ex_handler_uaccess_err_zero(const struct exception_table_entry= *ex, +static bool ex_handler_fixup_err_zero(const struct exception_table_entry *= ex, struct pt_regs *regs) { int reg_err =3D FIELD_GET(EX_DATA_REG_ERR, ex->data); @@ -69,7 +69,7 @@ bool fixup_exception(struct pt_regs *regs) return ex_handler_bpf(ex, regs); case EX_TYPE_UACCESS_ERR_ZERO: case EX_TYPE_KACCESS_ERR_ZERO: - return ex_handler_uaccess_err_zero(ex, regs); + return ex_handler_fixup_err_zero(ex, regs); case EX_TYPE_LOAD_UNALIGNED_ZEROPAD: return ex_handler_load_unaligned_zeropad(ex, regs); } @@ -87,7 +87,8 @@ bool fixup_exception_mc(struct pt_regs *regs) =20 switch (ex->type) { case EX_TYPE_UACCESS_ERR_ZERO: - return ex_handler_uaccess_err_zero(ex, regs); + case EX_TYPE_COPY_MC_PAGE_ERR_ZERO: + return ex_handler_fixup_err_zero(ex, regs); } =20 return false; diff --git a/include/linux/highmem.h b/include/linux/highmem.h index c29f51ea8517..b36ac0d99176 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -371,19 +371,23 @@ static inline int copy_mc_highpage(struct page *to, s= truct page *from) return ret ? -EFAULT : 0; } #else +#ifndef __HAVE_ARCH_COPY_MC_USER_HIGHPAGE static inline int copy_mc_user_highpage(struct page *to, struct page *from, unsigned long vaddr, struct vm_area_struct *vma) { copy_user_highpage(to, from, vaddr, vma); return 0; } +#endif =20 +#ifndef __HAVE_ARCH_COPY_MC_HIGHPAGE static inline int copy_mc_highpage(struct page *to, struct page *from) { copy_highpage(to, from); return 0; } #endif +#endif =20 static inline void memcpy_page(struct page *dst_page, size_t dst_off, struct page *src_page, size_t src_off, --=20 2.25.1