From patchwork Tue Dec 1 12:19:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 11942805 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 275EAC64E7B for ; Tue, 1 Dec 2020 12:20:11 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 847E82080A for ; Tue, 1 Dec 2020 12:20:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 847E82080A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 145026B0072; Tue, 1 Dec 2020 07:20:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0F5246B0073; Tue, 1 Dec 2020 07:20:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0320E8D0001; Tue, 1 Dec 2020 07:20:09 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0075.hostedemail.com [216.40.44.75]) by kanga.kvack.org (Postfix) with ESMTP id E32866B0072 for ; Tue, 1 Dec 2020 07:20:09 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id A8F5C3636 for ; Tue, 1 Dec 2020 12:20:09 +0000 (UTC) X-FDA: 77544620538.20.face61_5c026f2273aa Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin20.hostedemail.com (Postfix) with ESMTP id 83C55180C0609 for ; Tue, 1 Dec 2020 12:20:09 +0000 (UTC) X-HE-Tag: face61_5c026f2273aa X-Filterd-Recvd-Size: 9071 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Tue, 1 Dec 2020 12:20:08 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1EAF21063; Tue, 1 Dec 2020 04:20:08 -0800 (PST) Received: from p8cg001049571a15.arm.com (unknown [10.163.85.56]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 6C7813F718; Tue, 1 Dec 2020 04:20:02 -0800 (PST) From: Anshuman Khandual To: linux-mm@kvack.org, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com, steven.price@arm.com, christophe.leroy@csgroup.eu, gerald.schaefer@linux.ibm.com, vgupta@synopsys.com, paul.walmsley@sifive.com, Anshuman Khandual Subject: [PATCH V2 1/2] mm/debug_vm_pgtable/basic: Add validation for dirtiness after write protect Date: Tue, 1 Dec 2020 17:49:28 +0530 Message-Id: <1606825169-5229-2-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1606825169-5229-1-git-send-email-anshuman.khandual@arm.com> References: <1606825169-5229-1-git-send-email-anshuman.khandual@arm.com> 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: This adds validation tests for dirtiness after write protect conversion for each page table level. There are two new separate test types involved here. The first test ensures that a given page table entry does not become dirty after pxx_wrprotect(). This is important for platforms like arm64 which transfers and drops the hardware dirty bit (!PTE_RDONLY) to the software dirty bit while making it an write protected one. This test ensures that no fresh page table entry could be created with hardware dirty bit set. The second test ensures that a given page table entry always preserve the dirty information across pxx_wrprotect(). This adds two previously missing PUD level basic tests and while here fixes pxx_wrprotect() related typos in the documentation file. Cc: Andrew Morton Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Suggested-by: Catalin Marinas Signed-off-by: Anshuman Khandual --- Documentation/vm/arch_pgtable_helpers.rst | 8 ++--- mm/debug_vm_pgtable.c | 42 +++++++++++++++++++++++ 2 files changed, 46 insertions(+), 4 deletions(-) diff --git a/Documentation/vm/arch_pgtable_helpers.rst b/Documentation/vm/arch_pgtable_helpers.rst index f3591ee3aaa8..552567d863b8 100644 --- a/Documentation/vm/arch_pgtable_helpers.rst +++ b/Documentation/vm/arch_pgtable_helpers.rst @@ -50,7 +50,7 @@ PTE Page Table Helpers +---------------------------+--------------------------------------------------+ | pte_mkwrite | Creates a writable PTE | +---------------------------+--------------------------------------------------+ -| pte_mkwrprotect | Creates a write protected PTE | +| pte_wrprotect | Creates a write protected PTE | +---------------------------+--------------------------------------------------+ | pte_mkspecial | Creates a special PTE | +---------------------------+--------------------------------------------------+ @@ -120,7 +120,7 @@ PMD Page Table Helpers +---------------------------+--------------------------------------------------+ | pmd_mkwrite | Creates a writable PMD | +---------------------------+--------------------------------------------------+ -| pmd_mkwrprotect | Creates a write protected PMD | +| pmd_wrprotect | Creates a write protected PMD | +---------------------------+--------------------------------------------------+ | pmd_mkspecial | Creates a special PMD | +---------------------------+--------------------------------------------------+ @@ -186,7 +186,7 @@ PUD Page Table Helpers +---------------------------+--------------------------------------------------+ | pud_mkwrite | Creates a writable PUD | +---------------------------+--------------------------------------------------+ -| pud_mkwrprotect | Creates a write protected PUD | +| pud_wrprotect | Creates a write protected PUD | +---------------------------+--------------------------------------------------+ | pud_mkdevmap | Creates a ZONE_DEVICE mapped PUD | +---------------------------+--------------------------------------------------+ @@ -224,7 +224,7 @@ HugeTLB Page Table Helpers +---------------------------+--------------------------------------------------+ | huge_pte_mkwrite | Creates a writable HugeTLB | +---------------------------+--------------------------------------------------+ -| huge_pte_mkwrprotect | Creates a write protected HugeTLB | +| huge_pte_wrprotect | Creates a write protected HugeTLB | +---------------------------+--------------------------------------------------+ | huge_ptep_get_and_clear | Clears a HugeTLB | +---------------------------+--------------------------------------------------+ diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index c05d9dcf7891..c6fffea54522 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -63,6 +63,17 @@ static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot) pte_t pte = pfn_pte(pfn, prot); pr_debug("Validating PTE basic\n"); + + /* + * This test needs to execute right after the given page + * table entry is created with pfn_pte() to make sure that + * protection_map[idx] does not have the dirty bit enabled + * from the beginning. This is particularly important for + * platforms like arm64 where (!PTE_RDONLY) indicate dirty + * bit being set. + */ + WARN_ON(pte_dirty(pte_wrprotect(pte))); + WARN_ON(!pte_same(pte, pte)); WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte)))); WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte)))); @@ -70,6 +81,8 @@ static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot) WARN_ON(pte_young(pte_mkold(pte_mkyoung(pte)))); WARN_ON(pte_dirty(pte_mkclean(pte_mkdirty(pte)))); WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte)))); + WARN_ON(pte_dirty(pte_wrprotect(pte_mkclean(pte)))); + WARN_ON(!pte_dirty(pte_wrprotect(pte_mkdirty(pte)))); } static void __init pte_advanced_tests(struct mm_struct *mm, @@ -137,6 +150,18 @@ static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot) return; pr_debug("Validating PMD basic\n"); + + /* + * This test needs to execute right after the given page + * table entry is created with pfn_pmd() to make sure that + * protection_map[idx] does not have the dirty bit enabled + * from the beginning. This is particularly important for + * platforms like arm64 where (!PTE_RDONLY) indicate dirty + * bit being set. + */ + WARN_ON(pmd_dirty(pmd_wrprotect(pmd))); + + WARN_ON(!pmd_same(pmd, pmd)); WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd)))); WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd)))); @@ -144,6 +169,8 @@ static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot) WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd)))); WARN_ON(pmd_dirty(pmd_mkclean(pmd_mkdirty(pmd)))); WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd)))); + WARN_ON(pmd_dirty(pmd_wrprotect(pmd_mkclean(pmd)))); + WARN_ON(!pmd_dirty(pmd_wrprotect(pmd_mkdirty(pmd)))); /* * A huge page does not point to next level page table * entry. Hence this must qualify as pmd_bad(). @@ -257,11 +284,26 @@ static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) return; pr_debug("Validating PUD basic\n"); + + /* + * This test needs to execute right after the given page + * table entry is created with pfn_pud() to make sure that + * protection_map[idx] does not have the dirty bit enabled + * from the beginning. This is particularly important for + * platforms like arm64 where (!PTE_RDONLY) indicate dirty + * bit being set. + */ + WARN_ON(pud_dirty(pud_wrprotect(pud))); + WARN_ON(!pud_same(pud, pud)); WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud)))); + WARN_ON(!pud_dirty(pud_mkdirty(pud_mkclean(pud)))); + WARN_ON(pud_dirty(pud_mkclean(pud_mkdirty(pud)))); WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud)))); WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud)))); WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud)))); + WARN_ON(pud_dirty(pud_wrprotect(pud_mkclean(pud)))); + WARN_ON(!pud_dirty(pud_wrprotect(pud_mkdirty(pud)))); if (mm_pmd_folded(mm)) return; From patchwork Tue Dec 1 12:19:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 11942807 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 2C67FC64E7A for ; Tue, 1 Dec 2020 12:20:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 92C8020663 for ; Tue, 1 Dec 2020 12:20:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 92C8020663 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 22EF86B0073; Tue, 1 Dec 2020 07:20:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1DF498D0001; Tue, 1 Dec 2020 07:20:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 11C456B0075; Tue, 1 Dec 2020 07:20:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0018.hostedemail.com [216.40.44.18]) by kanga.kvack.org (Postfix) with ESMTP id F0C596B0073 for ; Tue, 1 Dec 2020 07:20:14 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id ABCCC180AD837 for ; Tue, 1 Dec 2020 12:20:14 +0000 (UTC) X-FDA: 77544620748.23.sack99_490a36a273aa Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin23.hostedemail.com (Postfix) with ESMTP id 8E25137604 for ; Tue, 1 Dec 2020 12:20:14 +0000 (UTC) X-HE-Tag: sack99_490a36a273aa X-Filterd-Recvd-Size: 8111 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Tue, 1 Dec 2020 12:20:13 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 35EA0106F; Tue, 1 Dec 2020 04:20:13 -0800 (PST) Received: from p8cg001049571a15.arm.com (unknown [10.163.85.56]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id DEB853F718; Tue, 1 Dec 2020 04:20:08 -0800 (PST) From: Anshuman Khandual To: linux-mm@kvack.org, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com, steven.price@arm.com, christophe.leroy@csgroup.eu, gerald.schaefer@linux.ibm.com, vgupta@synopsys.com, paul.walmsley@sifive.com, Anshuman Khandual Subject: [PATCH V2 2/2] mm/debug_vm_pgtable/basic: Iterate over entire protection_map[] Date: Tue, 1 Dec 2020 17:49:29 +0530 Message-Id: <1606825169-5229-3-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1606825169-5229-1-git-send-email-anshuman.khandual@arm.com> References: <1606825169-5229-1-git-send-email-anshuman.khandual@arm.com> 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: Currently the basic tests just validate various page table transformations after starting with vm_get_page_prot(VM_READ|VM_WRITE|VM_EXEC) protection. Instead scan over the entire protection_map[] for better coverage. It also makes sure that all these basic page table tranformations checks hold true irrespective of the starting protection value for the page table entry. There is also a slight change in the debug print format for basic tests to capture the protection value it is being tested with. The modified output looks something like [pte_basic_tests ]: Validating PTE basic () [pte_basic_tests ]: Validating PTE basic (read) [pte_basic_tests ]: Validating PTE basic (write) [pte_basic_tests ]: Validating PTE basic (read|write) [pte_basic_tests ]: Validating PTE basic (exec) [pte_basic_tests ]: Validating PTE basic (read|exec) [pte_basic_tests ]: Validating PTE basic (write|exec) [pte_basic_tests ]: Validating PTE basic (read|write|exec) [pte_basic_tests ]: Validating PTE basic (shared) [pte_basic_tests ]: Validating PTE basic (read|shared) [pte_basic_tests ]: Validating PTE basic (write|shared) [pte_basic_tests ]: Validating PTE basic (read|write|shared) [pte_basic_tests ]: Validating PTE basic (exec|shared) [pte_basic_tests ]: Validating PTE basic (read|exec|shared) [pte_basic_tests ]: Validating PTE basic (write|exec|shared) [pte_basic_tests ]: Validating PTE basic (read|write|exec|shared) This adds a missing argument 'struct mm_struct *' in pud_basic_tests() test . This never got exposed before as PUD based THP is available only on X86 platform where mm_pmd_folded(mm) call gets macro replaced without requiring the mm_struct i.e __is_defined(__PAGETABLE_PMD_FOLDED). Cc: Andrew Morton Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Steven Price Suggested-by: Catalin Marinas Signed-off-by: Anshuman Khandual --- mm/debug_vm_pgtable.c | 47 ++++++++++++++++++++++++++++++++----------- 1 file changed, 35 insertions(+), 12 deletions(-) diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index c6fffea54522..a96b5270e451 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -58,11 +58,13 @@ #define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK) #define RANDOM_NZVALUE GENMASK(7, 0) -static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot) +static void __init pte_basic_tests(unsigned long pfn, int idx) { + pgprot_t prot = protection_map[idx]; pte_t pte = pfn_pte(pfn, prot); + unsigned long val = idx, *ptr = &val; - pr_debug("Validating PTE basic\n"); + pr_debug("Validating PTE basic (%pGv)\n", ptr); /* * This test needs to execute right after the given page @@ -142,14 +144,16 @@ static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot) } #ifdef CONFIG_TRANSPARENT_HUGEPAGE -static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot) +static void __init pmd_basic_tests(unsigned long pfn, int idx) { + pgprot_t prot = protection_map[idx]; pmd_t pmd = pfn_pmd(pfn, prot); + unsigned long val = idx, *ptr = &val; if (!has_transparent_hugepage()) return; - pr_debug("Validating PMD basic\n"); + pr_debug("Validating PMD basic (%pGv)\n", ptr); /* * This test needs to execute right after the given page @@ -276,14 +280,16 @@ static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) } #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD -static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) +static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { + pgprot_t prot = protection_map[idx]; pud_t pud = pfn_pud(pfn, prot); + unsigned long val = idx, *ptr = &val; if (!has_transparent_hugepage()) return; - pr_debug("Validating PUD basic\n"); + pr_debug("Validating PUD basic (%pGv)\n", ptr); /* * This test needs to execute right after the given page @@ -401,7 +407,7 @@ static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) #endif /* !CONFIG_HAVE_ARCH_HUGE_VMAP */ #else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ -static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { } +static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { } static void __init pud_advanced_tests(struct mm_struct *mm, struct vm_area_struct *vma, pud_t *pudp, unsigned long pfn, unsigned long vaddr, @@ -414,8 +420,8 @@ static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) } #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ #else /* !CONFIG_TRANSPARENT_HUGEPAGE */ -static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot) { } -static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { } +static void __init pmd_basic_tests(unsigned long pfn, int idx) { } +static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { } static void __init pmd_advanced_tests(struct mm_struct *mm, struct vm_area_struct *vma, pmd_t *pmdp, unsigned long pfn, unsigned long vaddr, @@ -941,6 +947,7 @@ static int __init debug_vm_pgtable(void) unsigned long vaddr, pte_aligned, pmd_aligned; unsigned long pud_aligned, p4d_aligned, pgd_aligned; spinlock_t *ptl = NULL; + int idx; pr_info("Validating architecture page table helpers\n"); prot = vm_get_page_prot(VMFLAGS); @@ -1005,9 +1012,25 @@ static int __init debug_vm_pgtable(void) saved_pmdp = pmd_offset(pudp, 0UL); saved_ptep = pmd_pgtable(pmd); - pte_basic_tests(pte_aligned, prot); - pmd_basic_tests(pmd_aligned, prot); - pud_basic_tests(pud_aligned, prot); + /* + * Iterate over the protection_map[] to make sure that all + * the basic page table transformation validations just hold + * true irrespective of the starting protection value for a + * given page table entry. + */ + for (idx = 0; idx < ARRAY_SIZE(protection_map); idx++) { + pte_basic_tests(pte_aligned, idx); + pmd_basic_tests(pmd_aligned, idx); + pud_basic_tests(mm, pud_aligned, idx); + } + + /* + * Both P4D and PGD level tests are very basic which do not + * involve creating page table entries from the protection + * value and the given pfn. Hence just keep them out from + * the above iteration for now to save some test execution + * time. + */ p4d_basic_tests(p4d_aligned, prot); pgd_basic_tests(pgd_aligned, prot);