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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 6C0C7C433DF for ; Fri, 7 Aug 2020 06:19:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3EE65221E5 for ; Fri, 7 Aug 2020 06:19:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596781159; bh=HBFAslhuKXaOPh5f+h7wPd2tS96nNlCng1cIn0lEfEw=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=AX9yrzp2sKHjQf/3pErOgjhVy/+g4LgaWyRUcF6odUz51VZSNuM/z/JNUOI693NA6 pK/1r+kwDaY7FSCQaIPoQ0SxzIwC008QX/EUXj6WgK+p5cm+8B8p6QCl+pmKo+aER2 JsUlbbj6Omfv4szxXw9p8QHjC97r0zJKGmZmZ7Jo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726150AbgHGGTT (ORCPT ); Fri, 7 Aug 2020 02:19:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:54836 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725379AbgHGGTS (ORCPT ); Fri, 7 Aug 2020 02:19:18 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C73A12177B; Fri, 7 Aug 2020 06:19:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596781157; bh=HBFAslhuKXaOPh5f+h7wPd2tS96nNlCng1cIn0lEfEw=; h=Date:From:To:Subject:In-Reply-To:From; b=DskOLY6aRqmY3TTIn+Into42VoLe6KSqDgwjrRso2WHsgNVJnBnXqm7QHMzoFzRQ6 rHyNqLduW16V2W883FUQYw5Evrgl8yRAUL+PnddH84wKKii2jmGyS7f29BdLTqScXR SF0yAoIk+shdNFm/86k+zPqC7AvV+8Q0r1F6S1lY= Date: Thu, 06 Aug 2020 23:19:16 -0700 From: Andrew Morton To: akpm@linux-foundation.org, anshuman.khandual@arm.com, benh@kernel.crashing.org, borntraeger@de.ibm.com, bp@alien8.de, catalin.marinas@arm.com, corbet@lwn.net, gor@linux.ibm.com, heiko.carstens@de.ibm.com, hpa@zytor.com, kirill@shutemov.name, linux-mm@kvack.org, mingo@redhat.com, mm-commits@vger.kernel.org, mpe@ellerman.id.au, palmer@dabbelt.com, paul.walmsley@sifive.com, paulus@samba.org, rppt@kernel.org, rppt@linux.ibm.com, steven.price@arm.com, tglx@linutronix.de, torvalds@linux-foundation.org, vgupta@synopsys.com, will@kernel.org, ziy@nvidia.com Subject: [patch 040/163] mm/debug_vm_pgtable: add tests validating arch helpers for core MM features Message-ID: <20200807061916.zBaC-yU7x%akpm@linux-foundation.org> In-Reply-To: <20200806231643.a2711a608dd0f18bff2caf2b@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: mm-commits-owner@vger.kernel.org Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Anshuman Khandual Subject: mm/debug_vm_pgtable: add tests validating arch helpers for core MM features Patch series "mm/debug_vm_pgtable: Add some more tests", v5. This series adds some more arch page table helper validation tests which are related to core and advanced memory functions. This also creates a documentation, enlisting expected semantics for all page table helpers as suggested by Mike Rapoport previously (https://lkml.org/lkml/2020/1/30/40). There are many TRANSPARENT_HUGEPAGE and ARCH_HAS_TRANSPARENT_HUGEPAGE_PUD ifdefs scattered across the test. But consolidating all the fallback stubs is not very straight forward because ARCH_HAS_TRANSPARENT_HUGEPAGE_PUD is not explicitly dependent on ARCH_HAS_TRANSPARENT_HUGEPAGE. Tested on arm64, x86 platforms but only build tested on all other enabled platforms through ARCH_HAS_DEBUG_VM_PGTABLE i.e powerpc, arc, s390. The following failure on arm64 still exists which was mentioned previously. It will be fixed with the upcoming THP migration on arm64 enablement series. WARNING .... mm/debug_vm_pgtable.c:860 debug_vm_pgtable+0x940/0xa54 WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd)))) This patch (of 4): This adds new tests validating arch page table helpers for these following core memory features. These tests create and test specific mapping types at various page table levels. 1. SPECIAL mapping 2. PROTNONE mapping 3. DEVMAP mapping 4. SOFTDIRTY mapping 5. SWAP mapping 6. MIGRATION mapping 7. HUGETLB mapping 8. THP mapping Link: http://lkml.kernel.org/r/1594610587-4172-1-git-send-email-anshuman.khandual@arm.com Link: http://lkml.kernel.org/r/1593996516-7186-1-git-send-email-anshuman.khandual@arm.com Link: http://lkml.kernel.org/r/1593996516-7186-2-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Reviewed-by: Zi Yan Tested-by: Vineet Gupta [arc] Suggested-by: Catalin Marinas Cc: Mike Rapoport Cc: Vineet Gupta Cc: Catalin Marinas Cc: Will Deacon Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Kirill A. Shutemov Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Jonathan Corbet Cc: Mike Rapoport Cc: Steven Price Signed-off-by: Andrew Morton --- mm/debug_vm_pgtable.c | 302 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 301 insertions(+), 1 deletion(-) --- a/mm/debug_vm_pgtable.c~mm-debug_vm_pgtable-add-tests-validating-arch-helpers-for-core-mm-features +++ a/mm/debug_vm_pgtable.c @@ -282,6 +282,278 @@ static void __init pmd_populate_tests(st WARN_ON(pmd_bad(pmd)); } +static void __init pte_special_tests(unsigned long pfn, pgprot_t prot) +{ + pte_t pte = pfn_pte(pfn, prot); + + if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL)) + return; + + WARN_ON(!pte_special(pte_mkspecial(pte))); +} + +static void __init pte_protnone_tests(unsigned long pfn, pgprot_t prot) +{ + pte_t pte = pfn_pte(pfn, prot); + + if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) + return; + + WARN_ON(!pte_protnone(pte)); + WARN_ON(!pte_present(pte)); +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot) +{ + pmd_t pmd = pmd_mkhuge(pfn_pmd(pfn, prot)); + + if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) + return; + + WARN_ON(!pmd_protnone(pmd)); + WARN_ON(!pmd_present(pmd)); +} +#else /* !CONFIG_TRANSPARENT_HUGEPAGE */ +static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot) { } +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP +static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot) +{ + pte_t pte = pfn_pte(pfn, prot); + + WARN_ON(!pte_devmap(pte_mkdevmap(pte))); +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) +{ + pmd_t pmd = pfn_pmd(pfn, prot); + + WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd))); +} + +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD +static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) +{ + pud_t pud = pfn_pud(pfn, prot); + + WARN_ON(!pud_devmap(pud_mkdevmap(pud))); +} +#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ +static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { } +#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ +#else /* CONFIG_TRANSPARENT_HUGEPAGE */ +static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { } +static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { } +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#else +static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot) { } +static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { } +static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { } +#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */ + +static void __init pte_soft_dirty_tests(unsigned long pfn, pgprot_t prot) +{ + pte_t pte = pfn_pte(pfn, prot); + + if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) + return; + + WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte))); + WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte))); +} + +static void __init pte_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot) +{ + pte_t pte = pfn_pte(pfn, prot); + + if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) + return; + + WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte))); + WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte))); +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) +{ + pmd_t pmd = pfn_pmd(pfn, prot); + + if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) + return; + + WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd))); + WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd))); +} + +static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot) +{ + pmd_t pmd = pfn_pmd(pfn, prot); + + if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) || + !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION)) + return; + + WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd))); + WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd))); +} +#else /* !CONFIG_ARCH_HAS_PTE_DEVMAP */ +static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) { } +static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot) +{ +} +#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */ + +static void __init pte_swap_tests(unsigned long pfn, pgprot_t prot) +{ + swp_entry_t swp; + pte_t pte; + + pte = pfn_pte(pfn, prot); + swp = __pte_to_swp_entry(pte); + pte = __swp_entry_to_pte(swp); + WARN_ON(pfn != pte_pfn(pte)); +} + +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION +static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot) +{ + swp_entry_t swp; + pmd_t pmd; + + pmd = pfn_pmd(pfn, prot); + swp = __pmd_to_swp_entry(pmd); + pmd = __swp_entry_to_pmd(swp); + WARN_ON(pfn != pmd_pfn(pmd)); +} +#else /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */ +static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot) { } +#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */ + +static void __init swap_migration_tests(void) +{ + struct page *page; + swp_entry_t swp; + + if (!IS_ENABLED(CONFIG_MIGRATION)) + return; + /* + * swap_migration_tests() requires a dedicated page as it needs to + * be locked before creating a migration entry from it. Locking the + * page that actually maps kernel text ('start_kernel') can be real + * problematic. Lets allocate a dedicated page explicitly for this + * purpose that will be freed subsequently. + */ + page = alloc_page(GFP_KERNEL); + if (!page) { + pr_err("page allocation failed\n"); + return; + } + + /* + * make_migration_entry() expects given page to be + * locked, otherwise it stumbles upon a BUG_ON(). + */ + __SetPageLocked(page); + swp = make_migration_entry(page, 1); + WARN_ON(!is_migration_entry(swp)); + WARN_ON(!is_write_migration_entry(swp)); + + make_migration_entry_read(&swp); + WARN_ON(!is_migration_entry(swp)); + WARN_ON(is_write_migration_entry(swp)); + + swp = make_migration_entry(page, 0); + WARN_ON(!is_migration_entry(swp)); + WARN_ON(is_write_migration_entry(swp)); + __ClearPageLocked(page); + __free_page(page); +} + +#ifdef CONFIG_HUGETLB_PAGE +static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) +{ + struct page *page; + pte_t pte; + + /* + * Accessing the page associated with the pfn is safe here, + * as it was previously derived from a real kernel symbol. + */ + page = pfn_to_page(pfn); + pte = mk_huge_pte(page, prot); + + WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte))); + WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte)))); + WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte)))); + +#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB + pte = pfn_pte(pfn, prot); + + WARN_ON(!pte_huge(pte_mkhuge(pte))); +#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ +} +#else /* !CONFIG_HUGETLB_PAGE */ +static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { } +#endif /* CONFIG_HUGETLB_PAGE */ + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot) +{ + pmd_t pmd; + + if (!has_transparent_hugepage()) + return; + + /* + * pmd_trans_huge() and pmd_present() must return positive after + * MMU invalidation with pmd_mkinvalid(). This behavior is an + * optimization for transparent huge page. pmd_trans_huge() must + * be true if pmd_page() returns a valid THP to avoid taking the + * pmd_lock when others walk over non transhuge pmds (i.e. there + * are no THP allocated). Especially when splitting a THP and + * removing the present bit from the pmd, pmd_trans_huge() still + * needs to return true. pmd_present() should be true whenever + * pmd_trans_huge() returns true. + */ + pmd = pfn_pmd(pfn, prot); + WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd))); + +#ifndef __HAVE_ARCH_PMDP_INVALIDATE + WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd)))); + WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd)))); +#endif /* __HAVE_ARCH_PMDP_INVALIDATE */ +} + +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD +static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) +{ + pud_t pud; + + if (!has_transparent_hugepage()) + return; + + pud = pfn_pud(pfn, prot); + WARN_ON(!pud_trans_huge(pud_mkhuge(pud))); + + /* + * pud_mkinvalid() has been dropped for now. Enable back + * these tests when it comes back with a modified pud_present(). + * + * WARN_ON(!pud_trans_huge(pud_mkinvalid(pud_mkhuge(pud)))); + * WARN_ON(!pud_present(pud_mkinvalid(pud_mkhuge(pud)))); + */ +} +#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ +static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { } +#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ +#else /* !CONFIG_TRANSPARENT_HUGEPAGE */ +static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot) { } +static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { } +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + static unsigned long __init get_random_vaddr(void) { unsigned long random_vaddr, random_pages, total_user_pages; @@ -303,7 +575,7 @@ static int __init debug_vm_pgtable(void) pmd_t *pmdp, *saved_pmdp, pmd; pte_t *ptep; pgtable_t saved_ptep; - pgprot_t prot; + pgprot_t prot, protnone; phys_addr_t paddr; unsigned long vaddr, pte_aligned, pmd_aligned; unsigned long pud_aligned, p4d_aligned, pgd_aligned; @@ -319,6 +591,12 @@ static int __init debug_vm_pgtable(void) } /* + * __P000 (or even __S000) will help create page table entries with + * PROT_NONE permission as required for pxx_protnone_tests(). + */ + protnone = __P000; + + /* * PFN for mapping at PTE level is determined from a standard kernel * text symbol. But pfns for higher page table levels are derived by * masking lower bits of this real pfn. These derived pfns might not @@ -373,6 +651,28 @@ static int __init debug_vm_pgtable(void) p4d_populate_tests(mm, p4dp, saved_pudp); pgd_populate_tests(mm, pgdp, saved_p4dp); + pte_special_tests(pte_aligned, prot); + pte_protnone_tests(pte_aligned, protnone); + pmd_protnone_tests(pmd_aligned, protnone); + + pte_devmap_tests(pte_aligned, prot); + pmd_devmap_tests(pmd_aligned, prot); + pud_devmap_tests(pud_aligned, prot); + + pte_soft_dirty_tests(pte_aligned, prot); + pmd_soft_dirty_tests(pmd_aligned, prot); + pte_swap_soft_dirty_tests(pte_aligned, prot); + pmd_swap_soft_dirty_tests(pmd_aligned, prot); + + pte_swap_tests(pte_aligned, prot); + pmd_swap_tests(pmd_aligned, prot); + + swap_migration_tests(); + hugetlb_basic_tests(pte_aligned, prot); + + pmd_thp_tests(pmd_aligned, prot); + pud_thp_tests(pud_aligned, prot); + p4d_free(mm, saved_p4dp); pud_free(mm, saved_pudp); pmd_free(mm, saved_pmdp); _