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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3EB5C43216 for ; Mon, 9 Aug 2021 18:07:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A999960F02 for ; Mon, 9 Aug 2021 18:07:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234597AbhHISIH (ORCPT ); Mon, 9 Aug 2021 14:08:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:51854 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234456AbhHISHv (ORCPT ); Mon, 9 Aug 2021 14:07:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AD31960F02; Mon, 9 Aug 2021 18:07:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1628532450; bh=LMfY+r7ohAb+l9yM4hl1XNaHB7sv4FkLXkp/ZGNVyEA=; h=Date:From:To:Subject:From; b=SlOB3kh2z9CGUZzF9xqUxj4C4w190xIyYQOSwimqTAdSKa2i0OVHcVVxYpMwg1mWk 2vxXT6XpljaIgult6dUah8YkdAiG+ac2g9g0MetKxTPyK4gGMuDLzFJrw9ePKQpXYi Q0UJXR8Dp9aXaSEZTsiaKu5ngGmET5Va8Yzq/Tlc= Date: Mon, 09 Aug 2021 11:07:30 -0700 From: akpm@linux-foundation.org To: mm-commits@vger.kernel.org, will@kernel.org, vgupta@synopsys.com, gerald.schaefer@linux.ibm.com, chuhu@redhat.com, christophe.leroy@csgroup.eu, catalin.marinas@arm.com, cai@lca.pw, anshuman.khandual@arm.com, aneesh.kumar@linux.ibm.com, gshan@redhat.com Subject: + mm-debug_vm_pgtable-fix-corrupted-page-flag.patch added to -mm tree Message-ID: <20210809180730.F54wg%akpm@linux-foundation.org> User-Agent: s-nail v14.9.10 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm/debug_vm_pgtable: fix corrupted page flag has been added to the -mm tree. Its filename is mm-debug_vm_pgtable-fix-corrupted-page-flag.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-debug_vm_pgtable-fix-corrupted-page-flag.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-debug_vm_pgtable-fix-corrupted-page-flag.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: Gavin Shan Subject: mm/debug_vm_pgtable: fix corrupted page flag In page table entry modifying tests, set_xxx_at() are used to populate the page table entries. On ARM64, PG_arch_1 (PG_dcache_clean) flag is set to the target page flag if execution permission is given. The logic exits since commit 4f04d8f00545 ("arm64: MMU definitions"). The page flag is kept when the page is free'd to buddy's free area list. However, it will trigger page checking failure when it's pulled from the buddy's free area list, as the following warning messages indicate. BUG: Bad page state in process memhog pfn:08000 page:0000000015c0a628 refcount:0 mapcount:0 \ mapping:0000000000000000 index:0x1 pfn:0x8000 flags: 0x7ffff8000000800(arch_1|node=0|zone=0|lastcpupid=0xfffff) raw: 07ffff8000000800 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_PREP flag(s) set This fixes the issue by clearing PG_arch_1 through flush_dcache_page() after set_xxx_at() is called. For architectures other than ARM64, the unexpected overhead of cache flushing is acceptable. Link: https://lkml.kernel.org/r/20210809092631.1888748-13-gshan@redhat.com Fixes: a5c3b9ffb0f4 ("mm/debug_vm_pgtable: add tests validating advanced arch page table helpers") Signed-off-by: Gavin Shan Reviewed-by: Anshuman Khandual Tested-by: Christophe Leroy [powerpc 8xx] Cc: Aneesh Kumar K.V Cc: Catalin Marinas Cc: Chunyu Hu Cc: Gerald Schaefer Cc: Qian Cai Cc: Vineet Gupta Cc: Will Deacon Signed-off-by: Andrew Morton --- mm/debug_vm_pgtable.c | 55 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 51 insertions(+), 4 deletions(-) --- a/mm/debug_vm_pgtable.c~mm-debug_vm_pgtable-fix-corrupted-page-flag +++ a/mm/debug_vm_pgtable.c @@ -29,6 +29,8 @@ #include #include #include + +#include #include #include @@ -119,19 +121,28 @@ static void __init pte_basic_tests(struc static void __init pte_advanced_tests(struct pgtable_debug_args *args) { + struct page *page; pte_t pte; /* * Architectures optimize set_pte_at by avoiding TLB flush. * This requires set_pte_at to be not used to update an * existing pte entry. Clear pte before we do set_pte_at + * + * flush_dcache_page() is called after set_pte_at() to clear + * PG_arch_1 for the page on ARM64. The page flag isn't cleared + * when it's released and page allocation check will fail when + * the page is allocated again. For architectures other than ARM64, + * the unexpected overhead of cache flushing is acceptable. */ - if (args->pte_pfn == ULONG_MAX) + page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL; + if (!page) return; pr_debug("Validating PTE advanced\n"); pte = pfn_pte(args->pte_pfn, args->page_prot); set_pte_at(args->mm, args->vaddr, args->ptep, pte); + flush_dcache_page(page); ptep_set_wrprotect(args->mm, args->vaddr, args->ptep); pte = ptep_get(args->ptep); WARN_ON(pte_write(pte)); @@ -143,6 +154,7 @@ static void __init pte_advanced_tests(st pte = pte_wrprotect(pte); pte = pte_mkclean(pte); set_pte_at(args->mm, args->vaddr, args->ptep, pte); + flush_dcache_page(page); pte = pte_mkwrite(pte); pte = pte_mkdirty(pte); ptep_set_access_flags(args->vma, args->vaddr, args->ptep, pte, 1); @@ -155,6 +167,7 @@ static void __init pte_advanced_tests(st pte = pfn_pte(args->pte_pfn, args->page_prot); pte = pte_mkyoung(pte); set_pte_at(args->mm, args->vaddr, args->ptep, pte); + flush_dcache_page(page); ptep_test_and_clear_young(args->vma, args->vaddr, args->ptep); pte = ptep_get(args->ptep); WARN_ON(pte_young(pte)); @@ -213,15 +226,24 @@ static void __init pmd_basic_tests(struc static void __init pmd_advanced_tests(struct pgtable_debug_args *args) { + struct page *page; pmd_t pmd; unsigned long vaddr = args->vaddr; if (!has_transparent_hugepage()) return; - if (args->pmd_pfn == ULONG_MAX) + page = (args->pmd_pfn != ULONG_MAX) ? pfn_to_page(args->pmd_pfn) : NULL; + if (!page) return; + /* + * flush_dcache_page() is called after set_pmd_at() to clear + * PG_arch_1 for the page on ARM64. The page flag isn't cleared + * when it's released and page allocation check will fail when + * the page is allocated again. For architectures other than ARM64, + * the unexpected overhead of cache flushing is acceptable. + */ pr_debug("Validating PMD advanced\n"); /* Align the address wrt HPAGE_PMD_SIZE */ vaddr &= HPAGE_PMD_MASK; @@ -230,6 +252,7 @@ static void __init pmd_advanced_tests(st pmd = pfn_pmd(args->pmd_pfn, args->page_prot); set_pmd_at(args->mm, vaddr, args->pmdp, pmd); + flush_dcache_page(page); pmdp_set_wrprotect(args->mm, vaddr, args->pmdp); pmd = READ_ONCE(*args->pmdp); WARN_ON(pmd_write(pmd)); @@ -241,6 +264,7 @@ static void __init pmd_advanced_tests(st pmd = pmd_wrprotect(pmd); pmd = pmd_mkclean(pmd); set_pmd_at(args->mm, vaddr, args->pmdp, pmd); + flush_dcache_page(page); pmd = pmd_mkwrite(pmd); pmd = pmd_mkdirty(pmd); pmdp_set_access_flags(args->vma, vaddr, args->pmdp, pmd, 1); @@ -253,6 +277,7 @@ static void __init pmd_advanced_tests(st pmd = pmd_mkhuge(pfn_pmd(args->pmd_pfn, args->page_prot)); pmd = pmd_mkyoung(pmd); set_pmd_at(args->mm, vaddr, args->pmdp, pmd); + flush_dcache_page(page); pmdp_test_and_clear_young(args->vma, vaddr, args->pmdp); pmd = READ_ONCE(*args->pmdp); WARN_ON(pmd_young(pmd)); @@ -339,21 +364,31 @@ static void __init pud_basic_tests(struc static void __init pud_advanced_tests(struct pgtable_debug_args *args) { + struct page *page; unsigned long vaddr = args->vaddr; pud_t pud; if (!has_transparent_hugepage()) return; - if (args->pud_pfn == ULONG_MAX) + page = (args->pud_pfn != ULONG_MAX) ? pfn_to_page(args->pud_pfn) : NULL; + if (!page) return; + /* + * flush_dcache_page() is called after set_pud_at() to clear + * PG_arch_1 for the page on ARM64. The page flag isn't cleared + * when it's released and page allocation check will fail when + * the page is allocated again. For architectures other than ARM64, + * the unexpected overhead of cache flushing is acceptable. + */ pr_debug("Validating PUD advanced\n"); /* Align the address wrt HPAGE_PUD_SIZE */ vaddr &= HPAGE_PUD_MASK; pud = pfn_pud(args->pud_pfn, args->page_prot); set_pud_at(args->mm, vaddr, args->pudp, pud); + flush_dcache_page(page); pudp_set_wrprotect(args->mm, vaddr, args->pudp); pud = READ_ONCE(*args->pudp); WARN_ON(pud_write(pud)); @@ -367,6 +402,7 @@ static void __init pud_advanced_tests(st pud = pud_wrprotect(pud); pud = pud_mkclean(pud); set_pud_at(args->mm, vaddr, args->pudp, pud); + flush_dcache_page(page); pud = pud_mkwrite(pud); pud = pud_mkdirty(pud); pudp_set_access_flags(args->vma, vaddr, args->pudp, pud, 1); @@ -382,6 +418,7 @@ static void __init pud_advanced_tests(st pud = pfn_pud(args->pud_pfn, args->page_prot); pud = pud_mkyoung(pud); set_pud_at(args->mm, vaddr, args->pudp, pud); + flush_dcache_page(page); pudp_test_and_clear_young(args->vma, vaddr, args->pudp); pud = READ_ONCE(*args->pudp); WARN_ON(pud_young(pud)); @@ -594,16 +631,26 @@ static void __init pgd_populate_tests(st static void __init pte_clear_tests(struct pgtable_debug_args *args) { + struct page *page; pte_t pte = pfn_pte(args->pte_pfn, args->page_prot); - if (args->pte_pfn == ULONG_MAX) + page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL; + if (!page) return; + /* + * flush_dcache_page() is called after set_pte_at() to clear + * PG_arch_1 for the page on ARM64. The page flag isn't cleared + * when it's released and page allocation check will fail when + * the page is allocated again. For architectures other than ARM64, + * the unexpected overhead of cache flushing is acceptable. + */ pr_debug("Validating PTE clear\n"); #ifndef CONFIG_RISCV pte = __pte(pte_val(pte) | RANDOM_ORVALUE); #endif set_pte_at(args->mm, args->vaddr, args->ptep, pte); + flush_dcache_page(page); barrier(); pte_clear(args->mm, args->vaddr, args->ptep); pte = ptep_get(args->ptep); _ Patches currently in -mm which might be from gshan@redhat.com are mm-debug_vm_pgtable-introduce-struct-pgtable_debug_args.patch mm-debug_vm_pgtable-use-struct-pgtable_debug_args-in-basic-tests.patch mm-debug_vm_pgtable-use-struct-pgtable_debug_args-in-leaf-and-savewrite-tests.patch mm-debug_vm_pgtable-use-struct-pgtable_debug_args-in-protnone-and-devmap-tests.patch mm-debug_vm_pgtable-use-struct-pgtable_debug_args-in-soft_dirty-and-swap-tests.patch mm-debug_vm_pgtable-use-struct-pgtable_debug_args-in-migration-and-thp-tests.patch mm-debug_vm_pgtable-use-struct-pgtable_debug_args-in-pte-modifying-tests.patch mm-debug_vm_pgtable-use-struct-pgtable_debug_args-in-pmd-modifying-tests.patch mm-debug_vm_pgtable-use-struct-pgtable_debug_args-in-pud-modifying-tests.patch mm-debug_vm_pgtable-use-struct-pgtable_debug_args-in-pgd-and-p4d-modifying-tests.patch mm-debug_vm_pgtable-remove-unused-code.patch mm-debug_vm_pgtable-fix-corrupted-page-flag.patch