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Diffstat (limited to 'mm/debug_vm_pgtable.c')
| -rw-r--r-- | mm/debug_vm_pgtable.c | 1411 |
1 files changed, 1411 insertions, 0 deletions
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c new file mode 100644 index 000000000..48e329ea5 --- /dev/null +++ b/mm/debug_vm_pgtable.c @@ -0,0 +1,1411 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This kernel test validates architecture page table helpers and + * accessors and helps in verifying their continued compliance with + * expected generic MM semantics. + * + * Copyright (C) 2019 ARM Ltd. + * + * Author: Anshuman Khandual <anshuman.khandual@arm.com> + */ +#define pr_fmt(fmt) "debug_vm_pgtable: [%-25s]: " fmt, __func__ + +#include <linux/gfp.h> +#include <linux/highmem.h> +#include <linux/hugetlb.h> +#include <linux/kernel.h> +#include <linux/kconfig.h> +#include <linux/memblock.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/mm_types.h> +#include <linux/module.h> +#include <linux/pfn_t.h> +#include <linux/printk.h> +#include <linux/pgtable.h> +#include <linux/random.h> +#include <linux/spinlock.h> +#include <linux/swap.h> +#include <linux/swapops.h> +#include <linux/start_kernel.h> +#include <linux/sched/mm.h> +#include <linux/io.h> + +#include <asm/cacheflush.h> +#include <asm/pgalloc.h> +#include <asm/tlbflush.h> + +/* + * Please refer Documentation/mm/arch_pgtable_helpers.rst for the semantics + * expectations that are being validated here. All future changes in here + * or the documentation need to be in sync. + * + * On s390 platform, the lower 4 bits are used to identify given page table + * entry type. But these bits might affect the ability to clear entries with + * pxx_clear() because of how dynamic page table folding works on s390. So + * while loading up the entries do not change the lower 4 bits. It does not + * have affect any other platform. Also avoid the 62nd bit on ppc64 that is + * used to mark a pte entry. + */ +#define S390_SKIP_MASK GENMASK(3, 0) +#if __BITS_PER_LONG == 64 +#define PPC64_SKIP_MASK GENMASK(62, 62) +#else +#define PPC64_SKIP_MASK 0x0 +#endif +#define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK) +#define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK) +#define RANDOM_NZVALUE GENMASK(7, 0) + +struct pgtable_debug_args { + struct mm_struct *mm; + struct vm_area_struct *vma; + + pgd_t *pgdp; + p4d_t *p4dp; + pud_t *pudp; + pmd_t *pmdp; + pte_t *ptep; + + p4d_t *start_p4dp; + pud_t *start_pudp; + pmd_t *start_pmdp; + pgtable_t start_ptep; + + unsigned long vaddr; + pgprot_t page_prot; + pgprot_t page_prot_none; + + bool is_contiguous_page; + unsigned long pud_pfn; + unsigned long pmd_pfn; + unsigned long pte_pfn; + + unsigned long fixed_alignment; + unsigned long fixed_pgd_pfn; + unsigned long fixed_p4d_pfn; + unsigned long fixed_pud_pfn; + unsigned long fixed_pmd_pfn; + unsigned long fixed_pte_pfn; +}; + +static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx) +{ + pgprot_t prot = vm_get_page_prot(idx); + pte_t pte = pfn_pte(args->fixed_pte_pfn, prot); + unsigned long val = idx, *ptr = &val; + + pr_debug("Validating PTE basic (%pGv)\n", ptr); + + /* + * This test needs to be executed after the given page table entry + * is created with pfn_pte() to make sure that vm_get_page_prot(idx) + * does not have the dirty bit enabled from the beginning. This is + * 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)))); + WARN_ON(!pte_write(pte_mkwrite(pte_wrprotect(pte), args->vma))); + 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, args->vma)))); + 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 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. + */ + page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL; + if (!page) + return; + + pr_debug("Validating PTE advanced\n"); + if (WARN_ON(!args->ptep)) + 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)); + ptep_get_and_clear(args->mm, args->vaddr, args->ptep); + pte = ptep_get(args->ptep); + WARN_ON(!pte_none(pte)); + + pte = pfn_pte(args->pte_pfn, args->page_prot); + 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, args->vma); + pte = pte_mkdirty(pte); + ptep_set_access_flags(args->vma, args->vaddr, args->ptep, pte, 1); + pte = ptep_get(args->ptep); + WARN_ON(!(pte_write(pte) && pte_dirty(pte))); + ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1); + pte = ptep_get(args->ptep); + WARN_ON(!pte_none(pte)); + + 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)); + + ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1); +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx) +{ + pgprot_t prot = vm_get_page_prot(idx); + unsigned long val = idx, *ptr = &val; + pmd_t pmd; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PMD basic (%pGv)\n", ptr); + pmd = pfn_pmd(args->fixed_pmd_pfn, prot); + + /* + * This test needs to be executed after the given page table entry + * is created with pfn_pmd() to make sure that vm_get_page_prot(idx) + * does not have the dirty bit enabled from the beginning. This is + * 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)))); + WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd), args->vma))); + 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, args->vma)))); + 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(). + */ + WARN_ON(!pmd_bad(pmd_mkhuge(pmd))); +} + +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; + + 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; + + pgtable_trans_huge_deposit(args->mm, args->pmdp, args->start_ptep); + + 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)); + pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp); + pmd = READ_ONCE(*args->pmdp); + WARN_ON(!pmd_none(pmd)); + + pmd = pfn_pmd(args->pmd_pfn, args->page_prot); + 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, args->vma); + pmd = pmd_mkdirty(pmd); + pmdp_set_access_flags(args->vma, vaddr, args->pmdp, pmd, 1); + pmd = READ_ONCE(*args->pmdp); + WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd))); + pmdp_huge_get_and_clear_full(args->vma, vaddr, args->pmdp, 1); + pmd = READ_ONCE(*args->pmdp); + WARN_ON(!pmd_none(pmd)); + + 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)); + + /* Clear the pte entries */ + pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp); + pgtable_trans_huge_withdraw(args->mm, args->pmdp); +} + +static void __init pmd_leaf_tests(struct pgtable_debug_args *args) +{ + pmd_t pmd; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PMD leaf\n"); + pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot); + + /* + * PMD based THP is a leaf entry. + */ + pmd = pmd_mkhuge(pmd); + WARN_ON(!pmd_leaf(pmd)); +} + +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD +static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) +{ + pgprot_t prot = vm_get_page_prot(idx); + unsigned long val = idx, *ptr = &val; + pud_t pud; + + if (!has_transparent_pud_hugepage()) + return; + + pr_debug("Validating PUD basic (%pGv)\n", ptr); + pud = pfn_pud(args->fixed_pud_pfn, prot); + + /* + * This test needs to be executed after the given page table entry + * is created with pfn_pud() to make sure that vm_get_page_prot(idx) + * does not have the dirty bit enabled from the beginning. This is + * 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(args->mm)) + return; + + /* + * A huge page does not point to next level page table + * entry. Hence this must qualify as pud_bad(). + */ + WARN_ON(!pud_bad(pud_mkhuge(pud))); +} + +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_pud_hugepage()) + return; + + 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)); + +#ifndef __PAGETABLE_PMD_FOLDED + pudp_huge_get_and_clear(args->mm, vaddr, args->pudp); + pud = READ_ONCE(*args->pudp); + WARN_ON(!pud_none(pud)); +#endif /* __PAGETABLE_PMD_FOLDED */ + pud = pfn_pud(args->pud_pfn, args->page_prot); + 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); + pud = READ_ONCE(*args->pudp); + WARN_ON(!(pud_write(pud) && pud_dirty(pud))); + +#ifndef __PAGETABLE_PMD_FOLDED + pudp_huge_get_and_clear_full(args->vma, vaddr, args->pudp, 1); + pud = READ_ONCE(*args->pudp); + WARN_ON(!pud_none(pud)); +#endif /* __PAGETABLE_PMD_FOLDED */ + + 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)); + + pudp_huge_get_and_clear(args->mm, vaddr, args->pudp); +} + +static void __init pud_leaf_tests(struct pgtable_debug_args *args) +{ + pud_t pud; + + if (!has_transparent_pud_hugepage()) + return; + + pr_debug("Validating PUD leaf\n"); + pud = pfn_pud(args->fixed_pud_pfn, args->page_prot); + /* + * PUD based THP is a leaf entry. + */ + pud = pud_mkhuge(pud); + WARN_ON(!pud_leaf(pud)); +} +#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ +static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { } +static void __init pud_advanced_tests(struct pgtable_debug_args *args) { } +static void __init pud_leaf_tests(struct pgtable_debug_args *args) { } +#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ +#else /* !CONFIG_TRANSPARENT_HUGEPAGE */ +static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx) { } +static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { } +static void __init pmd_advanced_tests(struct pgtable_debug_args *args) { } +static void __init pud_advanced_tests(struct pgtable_debug_args *args) { } +static void __init pmd_leaf_tests(struct pgtable_debug_args *args) { } +static void __init pud_leaf_tests(struct pgtable_debug_args *args) { } +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP +static void __init pmd_huge_tests(struct pgtable_debug_args *args) +{ + pmd_t pmd; + + if (!arch_vmap_pmd_supported(args->page_prot) || + args->fixed_alignment < PMD_SIZE) + return; + + pr_debug("Validating PMD huge\n"); + /* + * X86 defined pmd_set_huge() verifies that the given + * PMD is not a populated non-leaf entry. + */ + WRITE_ONCE(*args->pmdp, __pmd(0)); + WARN_ON(!pmd_set_huge(args->pmdp, __pfn_to_phys(args->fixed_pmd_pfn), args->page_prot)); + WARN_ON(!pmd_clear_huge(args->pmdp)); + pmd = READ_ONCE(*args->pmdp); + WARN_ON(!pmd_none(pmd)); +} + +static void __init pud_huge_tests(struct pgtable_debug_args *args) +{ + pud_t pud; + + if (!arch_vmap_pud_supported(args->page_prot) || + args->fixed_alignment < PUD_SIZE) + return; + + pr_debug("Validating PUD huge\n"); + /* + * X86 defined pud_set_huge() verifies that the given + * PUD is not a populated non-leaf entry. + */ + WRITE_ONCE(*args->pudp, __pud(0)); + WARN_ON(!pud_set_huge(args->pudp, __pfn_to_phys(args->fixed_pud_pfn), args->page_prot)); + WARN_ON(!pud_clear_huge(args->pudp)); + pud = READ_ONCE(*args->pudp); + WARN_ON(!pud_none(pud)); +} +#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */ +static void __init pmd_huge_tests(struct pgtable_debug_args *args) { } +static void __init pud_huge_tests(struct pgtable_debug_args *args) { } +#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ + +static void __init p4d_basic_tests(struct pgtable_debug_args *args) +{ + p4d_t p4d; + + pr_debug("Validating P4D basic\n"); + memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t)); + WARN_ON(!p4d_same(p4d, p4d)); +} + +static void __init pgd_basic_tests(struct pgtable_debug_args *args) +{ + pgd_t pgd; + + pr_debug("Validating PGD basic\n"); + memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t)); + WARN_ON(!pgd_same(pgd, pgd)); +} + +#ifndef __PAGETABLE_PUD_FOLDED +static void __init pud_clear_tests(struct pgtable_debug_args *args) +{ + pud_t pud = READ_ONCE(*args->pudp); + + if (mm_pmd_folded(args->mm)) + return; + + pr_debug("Validating PUD clear\n"); + pud = __pud(pud_val(pud) | RANDOM_ORVALUE); + WRITE_ONCE(*args->pudp, pud); + pud_clear(args->pudp); + pud = READ_ONCE(*args->pudp); + WARN_ON(!pud_none(pud)); +} + +static void __init pud_populate_tests(struct pgtable_debug_args *args) +{ + pud_t pud; + + if (mm_pmd_folded(args->mm)) + return; + + pr_debug("Validating PUD populate\n"); + /* + * This entry points to next level page table page. + * Hence this must not qualify as pud_bad(). + */ + pud_populate(args->mm, args->pudp, args->start_pmdp); + pud = READ_ONCE(*args->pudp); + WARN_ON(pud_bad(pud)); +} +#else /* !__PAGETABLE_PUD_FOLDED */ +static void __init pud_clear_tests(struct pgtable_debug_args *args) { } +static void __init pud_populate_tests(struct pgtable_debug_args *args) { } +#endif /* PAGETABLE_PUD_FOLDED */ + +#ifndef __PAGETABLE_P4D_FOLDED +static void __init p4d_clear_tests(struct pgtable_debug_args *args) +{ + p4d_t p4d = READ_ONCE(*args->p4dp); + + if (mm_pud_folded(args->mm)) + return; + + pr_debug("Validating P4D clear\n"); + p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE); + WRITE_ONCE(*args->p4dp, p4d); + p4d_clear(args->p4dp); + p4d = READ_ONCE(*args->p4dp); + WARN_ON(!p4d_none(p4d)); +} + +static void __init p4d_populate_tests(struct pgtable_debug_args *args) +{ + p4d_t p4d; + + if (mm_pud_folded(args->mm)) + return; + + pr_debug("Validating P4D populate\n"); + /* + * This entry points to next level page table page. + * Hence this must not qualify as p4d_bad(). + */ + pud_clear(args->pudp); + p4d_clear(args->p4dp); + p4d_populate(args->mm, args->p4dp, args->start_pudp); + p4d = READ_ONCE(*args->p4dp); + WARN_ON(p4d_bad(p4d)); +} + +static void __init pgd_clear_tests(struct pgtable_debug_args *args) +{ + pgd_t pgd = READ_ONCE(*(args->pgdp)); + + if (mm_p4d_folded(args->mm)) + return; + + pr_debug("Validating PGD clear\n"); + pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE); + WRITE_ONCE(*args->pgdp, pgd); + pgd_clear(args->pgdp); + pgd = READ_ONCE(*args->pgdp); + WARN_ON(!pgd_none(pgd)); +} + +static void __init pgd_populate_tests(struct pgtable_debug_args *args) +{ + pgd_t pgd; + + if (mm_p4d_folded(args->mm)) + return; + + pr_debug("Validating PGD populate\n"); + /* + * This entry points to next level page table page. + * Hence this must not qualify as pgd_bad(). + */ + p4d_clear(args->p4dp); + pgd_clear(args->pgdp); + pgd_populate(args->mm, args->pgdp, args->start_p4dp); + pgd = READ_ONCE(*args->pgdp); + WARN_ON(pgd_bad(pgd)); +} +#else /* !__PAGETABLE_P4D_FOLDED */ +static void __init p4d_clear_tests(struct pgtable_debug_args *args) { } +static void __init pgd_clear_tests(struct pgtable_debug_args *args) { } +static void __init p4d_populate_tests(struct pgtable_debug_args *args) { } +static void __init pgd_populate_tests(struct pgtable_debug_args *args) { } +#endif /* PAGETABLE_P4D_FOLDED */ + +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); + + 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"); + if (WARN_ON(!args->ptep)) + return; + +#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(); + ptep_clear(args->mm, args->vaddr, args->ptep); + pte = ptep_get(args->ptep); + WARN_ON(!pte_none(pte)); +} + +static void __init pmd_clear_tests(struct pgtable_debug_args *args) +{ + pmd_t pmd = READ_ONCE(*args->pmdp); + + pr_debug("Validating PMD clear\n"); + pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE); + WRITE_ONCE(*args->pmdp, pmd); + pmd_clear(args->pmdp); + pmd = READ_ONCE(*args->pmdp); + WARN_ON(!pmd_none(pmd)); +} + +static void __init pmd_populate_tests(struct pgtable_debug_args *args) +{ + pmd_t pmd; + + pr_debug("Validating PMD populate\n"); + /* + * This entry points to next level page table page. + * Hence this must not qualify as pmd_bad(). + */ + pmd_populate(args->mm, args->pmdp, args->start_ptep); + pmd = READ_ONCE(*args->pmdp); + WARN_ON(pmd_bad(pmd)); +} + +static void __init pte_special_tests(struct pgtable_debug_args *args) +{ + pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot); + + if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL)) + return; + + pr_debug("Validating PTE special\n"); + WARN_ON(!pte_special(pte_mkspecial(pte))); +} + +static void __init pte_protnone_tests(struct pgtable_debug_args *args) +{ + pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot_none); + + if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) + return; + + pr_debug("Validating PTE protnone\n"); + WARN_ON(!pte_protnone(pte)); + WARN_ON(!pte_present(pte)); +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static void __init pmd_protnone_tests(struct pgtable_debug_args *args) +{ + pmd_t pmd; + + if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) + return; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PMD protnone\n"); + pmd = pmd_mkhuge(pfn_pmd(args->fixed_pmd_pfn, args->page_prot_none)); + WARN_ON(!pmd_protnone(pmd)); + WARN_ON(!pmd_present(pmd)); +} +#else /* !CONFIG_TRANSPARENT_HUGEPAGE */ +static void __init pmd_protnone_tests(struct pgtable_debug_args *args) { } +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP +static void __init pte_devmap_tests(struct pgtable_debug_args *args) +{ + pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot); + + pr_debug("Validating PTE devmap\n"); + WARN_ON(!pte_devmap(pte_mkdevmap(pte))); +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static void __init pmd_devmap_tests(struct pgtable_debug_args *args) +{ + pmd_t pmd; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PMD devmap\n"); + pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot); + WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd))); +} + +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD +static void __init pud_devmap_tests(struct pgtable_debug_args *args) +{ + pud_t pud; + + if (!has_transparent_pud_hugepage()) + return; + + pr_debug("Validating PUD devmap\n"); + pud = pfn_pud(args->fixed_pud_pfn, args->page_prot); + WARN_ON(!pud_devmap(pud_mkdevmap(pud))); +} +#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ +static void __init pud_devmap_tests(struct pgtable_debug_args *args) { } +#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ +#else /* CONFIG_TRANSPARENT_HUGEPAGE */ +static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { } +static void __init pud_devmap_tests(struct pgtable_debug_args *args) { } +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ +#else +static void __init pte_devmap_tests(struct pgtable_debug_args *args) { } +static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { } +static void __init pud_devmap_tests(struct pgtable_debug_args *args) { } +#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */ + +static void __init pte_soft_dirty_tests(struct pgtable_debug_args *args) +{ + pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot); + + if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) + return; + + pr_debug("Validating PTE soft dirty\n"); + 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(struct pgtable_debug_args *args) +{ + pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot); + + if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) + return; + + pr_debug("Validating PTE swap soft dirty\n"); + 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(struct pgtable_debug_args *args) +{ + pmd_t pmd; + + if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) + return; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PMD soft dirty\n"); + pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot); + 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(struct pgtable_debug_args *args) +{ + pmd_t pmd; + + if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) || + !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION)) + return; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PMD swap soft dirty\n"); + pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot); + 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_TRANSPARENT_HUGEPAGE */ +static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args) { } +static void __init pmd_swap_soft_dirty_tests(struct pgtable_debug_args *args) { } +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +static void __init pte_swap_exclusive_tests(struct pgtable_debug_args *args) +{ + unsigned long max_swap_offset; + swp_entry_t entry, entry2; + pte_t pte; + + pr_debug("Validating PTE swap exclusive\n"); + + /* See generic_max_swapfile_size(): probe the maximum offset */ + max_swap_offset = swp_offset(pte_to_swp_entry(swp_entry_to_pte(swp_entry(0, ~0UL)))); + + /* Create a swp entry with all possible bits set */ + entry = swp_entry((1 << MAX_SWAPFILES_SHIFT) - 1, max_swap_offset); + + pte = swp_entry_to_pte(entry); + WARN_ON(pte_swp_exclusive(pte)); + WARN_ON(!is_swap_pte(pte)); + entry2 = pte_to_swp_entry(pte); + WARN_ON(memcmp(&entry, &entry2, sizeof(entry))); + + pte = pte_swp_mkexclusive(pte); + WARN_ON(!pte_swp_exclusive(pte)); + WARN_ON(!is_swap_pte(pte)); + WARN_ON(pte_swp_soft_dirty(pte)); + entry2 = pte_to_swp_entry(pte); + WARN_ON(memcmp(&entry, &entry2, sizeof(entry))); + + pte = pte_swp_clear_exclusive(pte); + WARN_ON(pte_swp_exclusive(pte)); + WARN_ON(!is_swap_pte(pte)); + entry2 = pte_to_swp_entry(pte); + WARN_ON(memcmp(&entry, &entry2, sizeof(entry))); +} + +static void __init pte_swap_tests(struct pgtable_debug_args *args) +{ + swp_entry_t swp; + pte_t pte; + + pr_debug("Validating PTE swap\n"); + pte = pfn_pte(args->fixed_pte_pfn, args->page_prot); + swp = __pte_to_swp_entry(pte); + pte = __swp_entry_to_pte(swp); + WARN_ON(args->fixed_pte_pfn != pte_pfn(pte)); +} + +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION +static void __init pmd_swap_tests(struct pgtable_debug_args *args) +{ + swp_entry_t swp; + pmd_t pmd; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PMD swap\n"); + pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot); + swp = __pmd_to_swp_entry(pmd); + pmd = __swp_entry_to_pmd(swp); + WARN_ON(args->fixed_pmd_pfn != pmd_pfn(pmd)); +} +#else /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */ +static void __init pmd_swap_tests(struct pgtable_debug_args *args) { } +#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */ + +static void __init swap_migration_tests(struct pgtable_debug_args *args) +{ + 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 use the allocated page explicitly for this + * purpose. + */ + page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL; + if (!page) + return; + + pr_debug("Validating swap migration\n"); + + /* + * make_[readable|writable]_migration_entry() expects given page to + * be locked, otherwise it stumbles upon a BUG_ON(). + */ + __SetPageLocked(page); + swp = make_writable_migration_entry(page_to_pfn(page)); + WARN_ON(!is_migration_entry(swp)); + WARN_ON(!is_writable_migration_entry(swp)); + + swp = make_readable_migration_entry(swp_offset(swp)); + WARN_ON(!is_migration_entry(swp)); + WARN_ON(is_writable_migration_entry(swp)); + + swp = make_readable_migration_entry(page_to_pfn(page)); + WARN_ON(!is_migration_entry(swp)); + WARN_ON(is_writable_migration_entry(swp)); + __ClearPageLocked(page); +} + +#ifdef CONFIG_HUGETLB_PAGE +static void __init hugetlb_basic_tests(struct pgtable_debug_args *args) +{ + struct page *page; + pte_t pte; + + pr_debug("Validating HugeTLB basic\n"); + /* + * Accessing the page associated with the pfn is safe here, + * as it was previously derived from a real kernel symbol. + */ + page = pfn_to_page(args->fixed_pmd_pfn); + pte = mk_huge_pte(page, args->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(args->fixed_pmd_pfn, args->page_prot); + + WARN_ON(!pte_huge(arch_make_huge_pte(pte, PMD_SHIFT, VM_ACCESS_FLAGS))); +#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ +} +#else /* !CONFIG_HUGETLB_PAGE */ +static void __init hugetlb_basic_tests(struct pgtable_debug_args *args) { } +#endif /* CONFIG_HUGETLB_PAGE */ + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static void __init pmd_thp_tests(struct pgtable_debug_args *args) +{ + pmd_t pmd; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PMD based THP\n"); + /* + * 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(args->fixed_pmd_pfn, args->page_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(struct pgtable_debug_args *args) +{ + pud_t pud; + + if (!has_transparent_pud_hugepage()) + return; + + pr_debug("Validating PUD based THP\n"); + pud = pfn_pud(args->fixed_pud_pfn, args->page_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(struct pgtable_debug_args *args) { } +#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ +#else /* !CONFIG_TRANSPARENT_HUGEPAGE */ +static void __init pmd_thp_tests(struct pgtable_debug_args *args) { } +static void __init pud_thp_tests(struct pgtable_debug_args *args) { } +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +static unsigned long __init get_random_vaddr(void) +{ + unsigned long random_vaddr, random_pages, total_user_pages; + + total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE; + + random_pages = get_random_long() % total_user_pages; + random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE; + + return random_vaddr; +} + +static void __init destroy_args(struct pgtable_debug_args *args) +{ + struct page *page = NULL; + + /* Free (huge) page */ + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && + has_transparent_pud_hugepage() && + args->pud_pfn != ULONG_MAX) { + if (args->is_contiguous_page) { + free_contig_range(args->pud_pfn, + (1 << (HPAGE_PUD_SHIFT - PAGE_SHIFT))); + } else { + page = pfn_to_page(args->pud_pfn); + __free_pages(page, HPAGE_PUD_SHIFT - PAGE_SHIFT); + } + + args->pud_pfn = ULONG_MAX; + args->pmd_pfn = ULONG_MAX; + args->pte_pfn = ULONG_MAX; + } + + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && + has_transparent_hugepage() && + args->pmd_pfn != ULONG_MAX) { + if (args->is_contiguous_page) { + free_contig_range(args->pmd_pfn, (1 << HPAGE_PMD_ORDER)); + } else { + page = pfn_to_page(args->pmd_pfn); + __free_pages(page, HPAGE_PMD_ORDER); + } + + args->pmd_pfn = ULONG_MAX; + args->pte_pfn = ULONG_MAX; + } + + if (args->pte_pfn != ULONG_MAX) { + page = pfn_to_page(args->pte_pfn); + __free_page(page); + + args->pte_pfn = ULONG_MAX; + } + + /* Free page table entries */ + if (args->start_ptep) { + pte_free(args->mm, args->start_ptep); + mm_dec_nr_ptes(args->mm); + } + + if (args->start_pmdp) { + pmd_free(args->mm, args->start_pmdp); + mm_dec_nr_pmds(args->mm); + } + + if (args->start_pudp) { + pud_free(args->mm, args->start_pudp); + mm_dec_nr_puds(args->mm); + } + + if (args->start_p4dp) + p4d_free(args->mm, args->start_p4dp); + + /* Free vma and mm struct */ + if (args->vma) + vm_area_free(args->vma); + + if (args->mm) + mmdrop(args->mm); +} + +static struct page * __init +debug_vm_pgtable_alloc_huge_page(struct pgtable_debug_args *args, int order) +{ + struct page *page = NULL; + +#ifdef CONFIG_CONTIG_ALLOC + if (order > MAX_ORDER) { + page = alloc_contig_pages((1 << order), GFP_KERNEL, + first_online_node, NULL); + if (page) { + args->is_contiguous_page = true; + return page; + } + } +#endif + + if (order <= MAX_ORDER) + page = alloc_pages(GFP_KERNEL, order); + + return page; +} + +/* + * Check if a physical memory range described by <pstart, pend> contains + * an area that is of size psize, and aligned to psize. + * + * Don't use address 0, an all-zeroes physical address might mask bugs, and + * it's not used on x86. + */ +static void __init phys_align_check(phys_addr_t pstart, + phys_addr_t pend, unsigned long psize, + phys_addr_t *physp, unsigned long *alignp) +{ + phys_addr_t aligned_start, aligned_end; + + if (pstart == 0) + pstart = PAGE_SIZE; + + aligned_start = ALIGN(pstart, psize); + aligned_end = aligned_start + psize; + + if (aligned_end > aligned_start && aligned_end <= pend) { + *alignp = psize; + *physp = aligned_start; + } +} + +static void __init init_fixed_pfns(struct pgtable_debug_args *args) +{ + u64 idx; + phys_addr_t phys, pstart, pend; + + /* + * Initialize the fixed pfns. To do this, try to find a + * valid physical range, preferably aligned to PUD_SIZE, + * but settling for aligned to PMD_SIZE as a fallback. If + * neither of those is found, use the physical address of + * the start_kernel symbol. + * + * The memory doesn't need to be allocated, it just needs to exist + * as usable memory. It won't be touched. + * + * The alignment is recorded, and can be checked to see if we + * can run the tests that require an actual valid physical + * address range on some architectures ({pmd,pud}_huge_test + * on x86). + */ + + phys = __pa_symbol(&start_kernel); + args->fixed_alignment = PAGE_SIZE; + + for_each_mem_range(idx, &pstart, &pend) { + /* First check for a PUD-aligned area */ + phys_align_check(pstart, pend, PUD_SIZE, &phys, + &args->fixed_alignment); + + /* If a PUD-aligned area is found, we're done */ + if (args->fixed_alignment == PUD_SIZE) + break; + + /* + * If no PMD-aligned area found yet, check for one, + * but continue the loop to look for a PUD-aligned area. + */ + if (args->fixed_alignment < PMD_SIZE) + phys_align_check(pstart, pend, PMD_SIZE, &phys, + &args->fixed_alignment); + } + + args->fixed_pgd_pfn = __phys_to_pfn(phys & PGDIR_MASK); + args->fixed_p4d_pfn = __phys_to_pfn(phys & P4D_MASK); + args->fixed_pud_pfn = __phys_to_pfn(phys & PUD_MASK); + args->fixed_pmd_pfn = __phys_to_pfn(phys & PMD_MASK); + args->fixed_pte_pfn = __phys_to_pfn(phys & PAGE_MASK); + WARN_ON(!pfn_valid(args->fixed_pte_pfn)); +} + + +static int __init init_args(struct pgtable_debug_args *args) +{ + struct page *page = NULL; + int ret = 0; + + /* + * Initialize the debugging data. + * + * vm_get_page_prot(VM_NONE) or vm_get_page_prot(VM_SHARED|VM_NONE) + * will help create page table entries with PROT_NONE permission as + * required for pxx_protnone_tests(). + */ + memset(args, 0, sizeof(*args)); + args->vaddr = get_random_vaddr(); + args->page_prot = vm_get_page_prot(VM_ACCESS_FLAGS); + args->page_prot_none = vm_get_page_prot(VM_NONE); + args->is_contiguous_page = false; + args->pud_pfn = ULONG_MAX; + args->pmd_pfn = ULONG_MAX; + args->pte_pfn = ULONG_MAX; + args->fixed_pgd_pfn = ULONG_MAX; + args->fixed_p4d_pfn = ULONG_MAX; + args->fixed_pud_pfn = ULONG_MAX; + args->fixed_pmd_pfn = ULONG_MAX; + args->fixed_pte_pfn = ULONG_MAX; + + /* Allocate mm and vma */ + args->mm = mm_alloc(); + if (!args->mm) { + pr_err("Failed to allocate mm struct\n"); + ret = -ENOMEM; + goto error; + } + + args->vma = vm_area_alloc(args->mm); + if (!args->vma) { + pr_err("Failed to allocate vma\n"); + ret = -ENOMEM; + goto error; + } + + /* + * Allocate page table entries. They will be modified in the tests. + * Lets save the page table entries so that they can be released + * when the tests are completed. + */ + args->pgdp = pgd_offset(args->mm, args->vaddr); + args->p4dp = p4d_alloc(args->mm, args->pgdp, args->vaddr); + if (!args->p4dp) { + pr_err("Failed to allocate p4d entries\n"); + ret = -ENOMEM; + goto error; + } + args->start_p4dp = p4d_offset(args->pgdp, 0UL); + WARN_ON(!args->start_p4dp); + + args->pudp = pud_alloc(args->mm, args->p4dp, args->vaddr); + if (!args->pudp) { + pr_err("Failed to allocate pud entries\n"); + ret = -ENOMEM; + goto error; + } + args->start_pudp = pud_offset(args->p4dp, 0UL); + WARN_ON(!args->start_pudp); + + args->pmdp = pmd_alloc(args->mm, args->pudp, args->vaddr); + if (!args->pmdp) { + pr_err("Failed to allocate pmd entries\n"); + ret = -ENOMEM; + goto error; + } + args->start_pmdp = pmd_offset(args->pudp, 0UL); + WARN_ON(!args->start_pmdp); + + if (pte_alloc(args->mm, args->pmdp)) { + pr_err("Failed to allocate pte entries\n"); + ret = -ENOMEM; + goto error; + } + args->start_ptep = pmd_pgtable(READ_ONCE(*args->pmdp)); + WARN_ON(!args->start_ptep); + + init_fixed_pfns(args); + + /* + * Allocate (huge) pages because some of the tests need to access + * the data in the pages. The corresponding tests will be skipped + * if we fail to allocate (huge) pages. + */ + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && + has_transparent_pud_hugepage()) { + page = debug_vm_pgtable_alloc_huge_page(args, + HPAGE_PUD_SHIFT - PAGE_SHIFT); + if (page) { + args->pud_pfn = page_to_pfn(page); + args->pmd_pfn = args->pud_pfn; + args->pte_pfn = args->pud_pfn; + return 0; + } + } + + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && + has_transparent_hugepage()) { + page = debug_vm_pgtable_alloc_huge_page(args, HPAGE_PMD_ORDER); + if (page) { + args->pmd_pfn = page_to_pfn(page); + args->pte_pfn = args->pmd_pfn; + return 0; + } + } + + page = alloc_page(GFP_KERNEL); + if (page) + args->pte_pfn = page_to_pfn(page); + + return 0; + +error: + destroy_args(args); + return ret; +} + +static int __init debug_vm_pgtable(void) +{ + struct pgtable_debug_args args; + spinlock_t *ptl = NULL; + int idx, ret; + + pr_info("Validating architecture page table helpers\n"); + ret = init_args(&args); + if (ret) + return ret; + + /* + * Iterate over each possible vm_flags 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. + * + * Protection based vm_flags combinatins are always linear + * and increasing i.e starting from VM_NONE and going upto + * (VM_SHARED | READ | WRITE | EXEC). + */ +#define VM_FLAGS_START (VM_NONE) +#define VM_FLAGS_END (VM_SHARED | VM_EXEC | VM_WRITE | VM_READ) + + for (idx = VM_FLAGS_START; idx <= VM_FLAGS_END; idx++) { + pte_basic_tests(&args, idx); + pmd_basic_tests(&args, idx); + pud_basic_tests(&args, 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(&args); + pgd_basic_tests(&args); + + pmd_leaf_tests(&args); + pud_leaf_tests(&args); + + pte_special_tests(&args); + pte_protnone_tests(&args); + pmd_protnone_tests(&args); + + pte_devmap_tests(&args); + pmd_devmap_tests(&args); + pud_devmap_tests(&args); + + pte_soft_dirty_tests(&args); + pmd_soft_dirty_tests(&args); + pte_swap_soft_dirty_tests(&args); + pmd_swap_soft_dirty_tests(&args); + + pte_swap_exclusive_tests(&args); + + pte_swap_tests(&args); + pmd_swap_tests(&args); + + swap_migration_tests(&args); + + pmd_thp_tests(&args); + pud_thp_tests(&args); + + hugetlb_basic_tests(&args); + + /* + * Page table modifying tests. They need to hold + * proper page table lock. + */ + + args.ptep = pte_offset_map_lock(args.mm, args.pmdp, args.vaddr, &ptl); + pte_clear_tests(&args); + pte_advanced_tests(&args); + if (args.ptep) + pte_unmap_unlock(args.ptep, ptl); + + ptl = pmd_lock(args.mm, args.pmdp); + pmd_clear_tests(&args); + pmd_advanced_tests(&args); + pmd_huge_tests(&args); + pmd_populate_tests(&args); + spin_unlock(ptl); + + ptl = pud_lock(args.mm, args.pudp); + pud_clear_tests(&args); + pud_advanced_tests(&args); + pud_huge_tests(&args); + pud_populate_tests(&args); + spin_unlock(ptl); + + spin_lock(&(args.mm->page_table_lock)); + p4d_clear_tests(&args); + pgd_clear_tests(&args); + p4d_populate_tests(&args); + pgd_populate_tests(&args); + spin_unlock(&(args.mm->page_table_lock)); + + destroy_args(&args); + return 0; +} +late_initcall(debug_vm_pgtable); |