From patchwork Tue Jul 27 06:14:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 12401719 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2C7B1C4320A for ; Tue, 27 Jul 2021 06:15:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C5CAB61164 for ; Tue, 27 Jul 2021 06:15:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C5CAB61164 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 75BC66B0072; Tue, 27 Jul 2021 02:15:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 70C318D0001; Tue, 27 Jul 2021 02:15:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5FB036B0074; Tue, 27 Jul 2021 02:15:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0198.hostedemail.com [216.40.44.198]) by kanga.kvack.org (Postfix) with ESMTP id 463F66B0072 for ; Tue, 27 Jul 2021 02:15:27 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id F085117ABD for ; Tue, 27 Jul 2021 06:15:26 +0000 (UTC) X-FDA: 78407355852.23.F1000E4 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by imf13.hostedemail.com (Postfix) with ESMTP id 9D9E41016505 for ; Tue, 27 Jul 2021 06:15:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1627366526; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=//e0ERJu+bgqa9Pn7rPOIm8mUclcqfWjSdesgkJ2mrg=; b=UeTs2T3epI5NPhsa3HOtWuIS4iRJoMIt7HzAMu43nBi4sL6DnjiCMegrM84VIIUNRS/NfJ WpuVqs7of/VAPkVBSQcVdEyosbkxwm2KSeoPtaG0CsCgKlW//e40d5ufPbG5VVLNiOylsB SnHfZpAeOPmuNKBBYUrLtM5uEcjeDSw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-209-WBEPdo1BNdKeofiXqUYXrg-1; Tue, 27 Jul 2021 02:15:24 -0400 X-MC-Unique: WBEPdo1BNdKeofiXqUYXrg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A5A56804020; Tue, 27 Jul 2021 06:15:21 +0000 (UTC) Received: from gshan.redhat.com (vpn2-54-195.bne.redhat.com [10.64.54.195]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 868439C8CF; Tue, 27 Jul 2021 06:15:16 +0000 (UTC) From: Gavin Shan To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, anshuman.khandual@arm.com, gerald.schaefer@linux.ibm.com, aneesh.kumar@linux.ibm.com, christophe.leroy@csgroup.eu, cai@lca.pw, catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, chuhu@redhat.com, shan.gavin@gmail.com Subject: [PATCH v4 12/12] mm/debug_vm_pgtable: Fix corrupted page flag Date: Tue, 27 Jul 2021 14:14:01 +0800 Message-Id: <20210727061401.592616-13-gshan@redhat.com> In-Reply-To: <20210727061401.592616-1-gshan@redhat.com> References: <20210727061401.592616-1-gshan@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 9D9E41016505 Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=UeTs2T3e; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf13.hostedemail.com: domain of gshan@redhat.com has no SPF policy when checking 216.205.24.124) smtp.mailfrom=gshan@redhat.com X-Stat-Signature: 3ipis5fjf9o73b1ny9jpka1m8ryp33ug X-HE-Tag: 1627366526-148408 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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. Signed-off-by: Gavin Shan Reviewed-by: Anshuman Khandual --- mm/debug_vm_pgtable.c | 55 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 51 insertions(+), 4 deletions(-) diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index 162ff6329f7b..d2c2d23e542e 100644 --- a/mm/debug_vm_pgtable.c +++ b/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(struct pgtable_debug_args *args, int idx) 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(struct pgtable_debug_args *args) 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(struct pgtable_debug_args *args) 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(struct pgtable_debug_args *args, int idx) 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(struct pgtable_debug_args *args) 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(struct pgtable_debug_args *args) 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(struct pgtable_debug_args *args) 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(struct pgtable_debug_args *args, int idx) 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(struct pgtable_debug_args *args) 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(struct pgtable_debug_args *args) 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(struct pgtable_debug_args *args) { } 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);