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=-17.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 A4D67C12002 for ; Mon, 19 Jul 2021 13:08:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8324F6112D for ; Mon, 19 Jul 2021 13:08:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237426AbhGSM1e (ORCPT ); Mon, 19 Jul 2021 08:27:34 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:28446 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237362AbhGSM10 (ORCPT ); Mon, 19 Jul 2021 08:27:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626700085; 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=YYETNSKzJsjw/jBrOYshc2L1kxAcT1jYkb5uCWtb23E=; b=ax6qebUhenLr8Rw/FxVGvITyh9Ovzeedp2zf/pJNCYztHt/8t/0VF4KM1AUaweQYpxMubp wtCP10meBE7l24S98kBnG7IXhfY2WlYzcwHCiFma1nAJtQo2zY5TexTFNUJxuzT9YRXBws OHjW+g298wQ8tcum9NZil1Ti5ia24pM= 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-518-wRJ9PDZGPJemQGx4mPylgg-1; Mon, 19 Jul 2021 09:08:04 -0400 X-MC-Unique: wRJ9PDZGPJemQGx4mPylgg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 23FD4804142; Mon, 19 Jul 2021 13:08:03 +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 74DC65D6A1; Mon, 19 Jul 2021 13:07:59 +0000 (UTC) From: Gavin Shan To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, anshuman.khandual@arm.com, catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, chuhu@redhat.com, shan.gavin@gmail.com Subject: [PATCH v3 12/12] mm/debug_vm_pgtable: Fix corrupted page flag Date: Mon, 19 Jul 2021 21:06:13 +0800 Message-Id: <20210719130613.334901-13-gshan@redhat.com> In-Reply-To: <20210719130613.334901-1-gshan@redhat.com> References: <20210719130613.334901-1-gshan@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In page table entry modifying tests, set_xxx_at() are used to populate the page table entries. On ARM64, PG_arch_1 is set to the target page flag if execution permission is given. 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. Signed-off-by: Gavin Shan --- mm/debug_vm_pgtable.c | 32 ++++++++++++++++++++++++++++---- 1 file changed, 28 insertions(+), 4 deletions(-) diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index 4f7bf1c9724a..de9def6f7ce1 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -29,6 +29,8 @@ #include #include #include + +#include #include #include @@ -118,6 +120,7 @@ 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; /* @@ -127,13 +130,16 @@ static void __init pte_advanced_tests(struct pgtable_debug_args *args) */ pr_debug("Validating PTE advanced\n"); - if (args->pte_pfn == ULONG_MAX) { + page = (args->pte_pfn != ULONG_MAX) ? + pfn_to_page(args->pte_pfn) : NULL; + if (!page) { pr_debug("%s: Skipped\n", __func__); return; } 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)); @@ -145,6 +151,7 @@ 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); @@ -157,6 +164,7 @@ 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)); @@ -215,6 +223,7 @@ 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 & HPAGE_PMD_MASK); @@ -222,7 +231,9 @@ static void __init pmd_advanced_tests(struct pgtable_debug_args *args) return; pr_debug("Validating PMD advanced\n"); - if (args->pmd_pfn == ULONG_MAX) { + page = (args->pmd_pfn != ULONG_MAX) ? + pfn_to_page(args->pmd_pfn) : NULL; + if (!page) { pr_debug("%s: Skipped\n", __func__); return; } @@ -231,6 +242,7 @@ 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)); @@ -242,6 +254,7 @@ 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); @@ -254,6 +267,7 @@ 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)); @@ -340,6 +354,7 @@ 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 & HPAGE_PUD_MASK); pud_t pud; @@ -347,13 +362,16 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args) return; pr_debug("Validating PUD advanced\n"); - if (args->pud_pfn == ULONG_MAX) { + page = (args->pud_pfn != ULONG_MAX) ? + pfn_to_page(args->pud_pfn) : NULL; + if (!page) { pr_debug("%s: Skipped\n", __func__); return; } 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 +385,7 @@ 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 +401,7 @@ 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)); @@ -596,10 +616,13 @@ 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; pr_debug("Validating PTE clear\n"); - if (args->pte_pfn == ULONG_MAX) { + page = (args->pte_pfn != ULONG_MAX) ? + pfn_to_page(args->pte_pfn) : NULL; + if (!page) { pr_debug("%s: Skipped\n", __func__); return; } @@ -609,6 +632,7 @@ static void __init pte_clear_tests(struct pgtable_debug_args *args) 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); -- 2.23.0