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Diffstat (limited to 'mm/debug_vm_pgtable.c')
| -rw-r--r-- | mm/debug_vm_pgtable.c | 1147 |
1 files changed, 1147 insertions, 0 deletions
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c new file mode 100644 index 000000000..d6fbf28eb --- /dev/null +++ b/mm/debug_vm_pgtable.c @@ -0,0 +1,1147 @@ +// 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/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/pgalloc.h> +#include <asm/tlbflush.h> + +/* + * Please refer Documentation/vm/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. + */ + +#define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC) + +/* + * 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) + +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 (%pGv)\n", ptr); + + /* + * This test needs to be executed 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 + * 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)))); + 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, + struct vm_area_struct *vma, pte_t *ptep, + unsigned long pfn, unsigned long vaddr, + pgprot_t prot) +{ + pte_t pte = pfn_pte(pfn, prot); + + /* + * 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 + */ + + pr_debug("Validating PTE advanced\n"); + pte = pfn_pte(pfn, prot); + set_pte_at(mm, vaddr, ptep, pte); + ptep_set_wrprotect(mm, vaddr, ptep); + pte = ptep_get(ptep); + WARN_ON(pte_write(pte)); + ptep_get_and_clear(mm, vaddr, ptep); + pte = ptep_get(ptep); + WARN_ON(!pte_none(pte)); + + pte = pfn_pte(pfn, prot); + pte = pte_wrprotect(pte); + pte = pte_mkclean(pte); + set_pte_at(mm, vaddr, ptep, pte); + pte = pte_mkwrite(pte); + pte = pte_mkdirty(pte); + ptep_set_access_flags(vma, vaddr, ptep, pte, 1); + pte = ptep_get(ptep); + WARN_ON(!(pte_write(pte) && pte_dirty(pte))); + ptep_get_and_clear_full(mm, vaddr, ptep, 1); + pte = ptep_get(ptep); + WARN_ON(!pte_none(pte)); + + pte = pfn_pte(pfn, prot); + pte = pte_mkyoung(pte); + set_pte_at(mm, vaddr, ptep, pte); + ptep_test_and_clear_young(vma, vaddr, ptep); + pte = ptep_get(ptep); + WARN_ON(pte_young(pte)); + + ptep_get_and_clear_full(mm, vaddr, ptep, 1); +} + +static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot) +{ + pte_t pte = pfn_pte(pfn, prot); + + if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) + return; + + pr_debug("Validating PTE saved write\n"); + WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte)))); + WARN_ON(pte_savedwrite(pte_clear_savedwrite(pte_mk_savedwrite(pte)))); +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static void __init pmd_basic_tests(unsigned long pfn, int idx) +{ + pgprot_t prot = protection_map[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(pfn, prot); + + /* + * This test needs to be executed 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 + * 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)))); + 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(). + */ + WARN_ON(!pmd_bad(pmd_mkhuge(pmd))); +} + +static void __init pmd_advanced_tests(struct mm_struct *mm, + struct vm_area_struct *vma, pmd_t *pmdp, + unsigned long pfn, unsigned long vaddr, + pgprot_t prot, pgtable_t pgtable) +{ + pmd_t pmd; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PMD advanced\n"); + /* Align the address wrt HPAGE_PMD_SIZE */ + vaddr &= HPAGE_PMD_MASK; + + pgtable_trans_huge_deposit(mm, pmdp, pgtable); + + pmd = pfn_pmd(pfn, prot); + set_pmd_at(mm, vaddr, pmdp, pmd); + pmdp_set_wrprotect(mm, vaddr, pmdp); + pmd = READ_ONCE(*pmdp); + WARN_ON(pmd_write(pmd)); + pmdp_huge_get_and_clear(mm, vaddr, pmdp); + pmd = READ_ONCE(*pmdp); + WARN_ON(!pmd_none(pmd)); + + pmd = pfn_pmd(pfn, prot); + pmd = pmd_wrprotect(pmd); + pmd = pmd_mkclean(pmd); + set_pmd_at(mm, vaddr, pmdp, pmd); + pmd = pmd_mkwrite(pmd); + pmd = pmd_mkdirty(pmd); + pmdp_set_access_flags(vma, vaddr, pmdp, pmd, 1); + pmd = READ_ONCE(*pmdp); + WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd))); + pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1); + pmd = READ_ONCE(*pmdp); + WARN_ON(!pmd_none(pmd)); + + pmd = pmd_mkhuge(pfn_pmd(pfn, prot)); + pmd = pmd_mkyoung(pmd); + set_pmd_at(mm, vaddr, pmdp, pmd); + pmdp_test_and_clear_young(vma, vaddr, pmdp); + pmd = READ_ONCE(*pmdp); + WARN_ON(pmd_young(pmd)); + + /* Clear the pte entries */ + pmdp_huge_get_and_clear(mm, vaddr, pmdp); + pgtable = pgtable_trans_huge_withdraw(mm, pmdp); +} + +static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) +{ + pmd_t pmd; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PMD leaf\n"); + pmd = pfn_pmd(pfn, prot); + + /* + * PMD based THP is a leaf entry. + */ + pmd = pmd_mkhuge(pmd); + WARN_ON(!pmd_leaf(pmd)); +} + +#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP +static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) +{ + pmd_t pmd; + + if (!arch_ioremap_pmd_supported()) + 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(*pmdp, __pmd(0)); + WARN_ON(!pmd_set_huge(pmdp, __pfn_to_phys(pfn), prot)); + WARN_ON(!pmd_clear_huge(pmdp)); + pmd = READ_ONCE(*pmdp); + WARN_ON(!pmd_none(pmd)); +} +#else /* CONFIG_HAVE_ARCH_HUGE_VMAP */ +static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) { } +#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ + +static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) +{ + pmd_t pmd; + + if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) + return; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PMD saved write\n"); + pmd = pfn_pmd(pfn, prot); + WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd)))); + WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd)))); +} + +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD +static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) +{ + pgprot_t prot = protection_map[idx]; + unsigned long val = idx, *ptr = &val; + pud_t pud; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PUD basic (%pGv)\n", ptr); + pud = pfn_pud(pfn, prot); + + /* + * This test needs to be executed 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 + * 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; + + /* + * 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 mm_struct *mm, + struct vm_area_struct *vma, pud_t *pudp, + unsigned long pfn, unsigned long vaddr, + pgprot_t prot) +{ + pud_t pud; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PUD advanced\n"); + /* Align the address wrt HPAGE_PUD_SIZE */ + vaddr &= HPAGE_PUD_MASK; + + pud = pfn_pud(pfn, prot); + set_pud_at(mm, vaddr, pudp, pud); + pudp_set_wrprotect(mm, vaddr, pudp); + pud = READ_ONCE(*pudp); + WARN_ON(pud_write(pud)); + +#ifndef __PAGETABLE_PMD_FOLDED + pudp_huge_get_and_clear(mm, vaddr, pudp); + pud = READ_ONCE(*pudp); + WARN_ON(!pud_none(pud)); +#endif /* __PAGETABLE_PMD_FOLDED */ + pud = pfn_pud(pfn, prot); + pud = pud_wrprotect(pud); + pud = pud_mkclean(pud); + set_pud_at(mm, vaddr, pudp, pud); + pud = pud_mkwrite(pud); + pud = pud_mkdirty(pud); + pudp_set_access_flags(vma, vaddr, pudp, pud, 1); + pud = READ_ONCE(*pudp); + WARN_ON(!(pud_write(pud) && pud_dirty(pud))); + +#ifndef __PAGETABLE_PMD_FOLDED + pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1); + pud = READ_ONCE(*pudp); + WARN_ON(!pud_none(pud)); +#endif /* __PAGETABLE_PMD_FOLDED */ + + pud = pfn_pud(pfn, prot); + pud = pud_mkyoung(pud); + set_pud_at(mm, vaddr, pudp, pud); + pudp_test_and_clear_young(vma, vaddr, pudp); + pud = READ_ONCE(*pudp); + WARN_ON(pud_young(pud)); + + pudp_huge_get_and_clear(mm, vaddr, pudp); +} + +static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) +{ + pud_t pud; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PUD leaf\n"); + pud = pfn_pud(pfn, prot); + /* + * PUD based THP is a leaf entry. + */ + pud = pud_mkhuge(pud); + WARN_ON(!pud_leaf(pud)); +} + +#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP +static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) +{ + pud_t pud; + + if (!arch_ioremap_pud_supported()) + 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(*pudp, __pud(0)); + WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot)); + WARN_ON(!pud_clear_huge(pudp)); + pud = READ_ONCE(*pudp); + WARN_ON(!pud_none(pud)); +} +#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */ +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(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, + pgprot_t prot) +{ +} +static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { } +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, 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, + pgprot_t prot, pgtable_t pgtable) +{ +} +static void __init pud_advanced_tests(struct mm_struct *mm, + struct vm_area_struct *vma, pud_t *pudp, + unsigned long pfn, unsigned long vaddr, + pgprot_t prot) +{ +} +static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) { } +static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { } +static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) +{ +} +static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) +{ +} +static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) { } +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot) +{ + 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(unsigned long pfn, pgprot_t prot) +{ + 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 mm_struct *mm, pud_t *pudp) +{ + pud_t pud = READ_ONCE(*pudp); + + if (mm_pmd_folded(mm)) + return; + + pr_debug("Validating PUD clear\n"); + pud = __pud(pud_val(pud) | RANDOM_ORVALUE); + WRITE_ONCE(*pudp, pud); + pud_clear(pudp); + pud = READ_ONCE(*pudp); + WARN_ON(!pud_none(pud)); +} + +static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp, + pmd_t *pmdp) +{ + pud_t pud; + + if (mm_pmd_folded(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(mm, pudp, pmdp); + pud = READ_ONCE(*pudp); + WARN_ON(pud_bad(pud)); +} +#else /* !__PAGETABLE_PUD_FOLDED */ +static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) { } +static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp, + pmd_t *pmdp) +{ +} +#endif /* PAGETABLE_PUD_FOLDED */ + +#ifndef __PAGETABLE_P4D_FOLDED +static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) +{ + p4d_t p4d = READ_ONCE(*p4dp); + + if (mm_pud_folded(mm)) + return; + + pr_debug("Validating P4D clear\n"); + p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE); + WRITE_ONCE(*p4dp, p4d); + p4d_clear(p4dp); + p4d = READ_ONCE(*p4dp); + WARN_ON(!p4d_none(p4d)); +} + +static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp, + pud_t *pudp) +{ + p4d_t p4d; + + if (mm_pud_folded(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(pudp); + p4d_clear(p4dp); + p4d_populate(mm, p4dp, pudp); + p4d = READ_ONCE(*p4dp); + WARN_ON(p4d_bad(p4d)); +} + +static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) +{ + pgd_t pgd = READ_ONCE(*pgdp); + + if (mm_p4d_folded(mm)) + return; + + pr_debug("Validating PGD clear\n"); + pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE); + WRITE_ONCE(*pgdp, pgd); + pgd_clear(pgdp); + pgd = READ_ONCE(*pgdp); + WARN_ON(!pgd_none(pgd)); +} + +static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp, + p4d_t *p4dp) +{ + pgd_t pgd; + + if (mm_p4d_folded(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(p4dp); + pgd_clear(pgdp); + pgd_populate(mm, pgdp, p4dp); + pgd = READ_ONCE(*pgdp); + WARN_ON(pgd_bad(pgd)); +} +#else /* !__PAGETABLE_P4D_FOLDED */ +static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { } +static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { } +static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp, + pud_t *pudp) +{ +} +static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp, + p4d_t *p4dp) +{ +} +#endif /* PAGETABLE_P4D_FOLDED */ + +static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep, + unsigned long pfn, unsigned long vaddr, + pgprot_t prot) +{ + pte_t pte = pfn_pte(pfn, prot); + + pr_debug("Validating PTE clear\n"); +#ifndef CONFIG_RISCV + pte = __pte(pte_val(pte) | RANDOM_ORVALUE); +#endif + set_pte_at(mm, vaddr, ptep, pte); + barrier(); + pte_clear(mm, vaddr, ptep); + pte = ptep_get(ptep); + WARN_ON(!pte_none(pte)); +} + +static void __init pmd_clear_tests(struct mm_struct *mm, pmd_t *pmdp) +{ + pmd_t pmd = READ_ONCE(*pmdp); + + pr_debug("Validating PMD clear\n"); + pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE); + WRITE_ONCE(*pmdp, pmd); + pmd_clear(pmdp); + pmd = READ_ONCE(*pmdp); + WARN_ON(!pmd_none(pmd)); +} + +static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp, + pgtable_t pgtable) +{ + 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(mm, pmdp, pgtable); + pmd = READ_ONCE(*pmdp); + 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; + + pr_debug("Validating PTE special\n"); + 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; + + 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(unsigned long pfn, pgprot_t prot) +{ + 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(pfn, prot)); + 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); + + pr_debug("Validating PTE devmap\n"); + 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; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PMD devmap\n"); + 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; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PUD devmap\n"); + 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; + + 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(unsigned long pfn, pgprot_t prot) +{ + pte_t pte = pfn_pte(pfn, 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(unsigned long pfn, pgprot_t prot) +{ + 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(pfn, 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(unsigned long pfn, pgprot_t prot) +{ + 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(pfn, 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_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; + + pr_debug("Validating PTE swap\n"); + 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; + + if (!has_transparent_hugepage()) + return; + + pr_debug("Validating PMD swap\n"); + 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; + + pr_debug("Validating swap migration\n"); + /* + * 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; + + 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(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; + + 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(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; + + pr_debug("Validating PUD based THP\n"); + 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; + + 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 int __init debug_vm_pgtable(void) +{ + struct vm_area_struct *vma; + struct mm_struct *mm; + pgd_t *pgdp; + p4d_t *p4dp, *saved_p4dp; + pud_t *pudp, *saved_pudp; + pmd_t *pmdp, *saved_pmdp, pmd; + pte_t *ptep; + pgtable_t saved_ptep; + pgprot_t prot, protnone; + phys_addr_t paddr; + 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); + vaddr = get_random_vaddr(); + mm = mm_alloc(); + if (!mm) { + pr_err("mm_struct allocation failed\n"); + return 1; + } + + /* + * __P000 (or even __S000) will help create page table entries with + * PROT_NONE permission as required for pxx_protnone_tests(). + */ + protnone = __P000; + + vma = vm_area_alloc(mm); + if (!vma) { + pr_err("vma allocation failed\n"); + return 1; + } + + /* + * 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 + * exist on the platform but that does not really matter as pfn_pxx() + * helpers will still create appropriate entries for the test. This + * helps avoid large memory block allocations to be used for mapping + * at higher page table levels. + */ + paddr = __pa_symbol(&start_kernel); + + pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT; + pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT; + pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT; + p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT; + pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT; + WARN_ON(!pfn_valid(pte_aligned)); + + pgdp = pgd_offset(mm, vaddr); + p4dp = p4d_alloc(mm, pgdp, vaddr); + pudp = pud_alloc(mm, p4dp, vaddr); + pmdp = pmd_alloc(mm, pudp, vaddr); + /* + * Allocate pgtable_t + */ + if (pte_alloc(mm, pmdp)) { + pr_err("pgtable allocation failed\n"); + return 1; + } + + /* + * Save all the page table page addresses as the page table + * entries will be used for testing with random or garbage + * values. These saved addresses will be used for freeing + * page table pages. + */ + pmd = READ_ONCE(*pmdp); + saved_p4dp = p4d_offset(pgdp, 0UL); + saved_pudp = pud_offset(p4dp, 0UL); + saved_pmdp = pmd_offset(pudp, 0UL); + saved_ptep = pmd_pgtable(pmd); + + /* + * 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); + + pmd_leaf_tests(pmd_aligned, prot); + pud_leaf_tests(pud_aligned, prot); + + pte_savedwrite_tests(pte_aligned, protnone); + pmd_savedwrite_tests(pmd_aligned, protnone); + + 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(); + + pmd_thp_tests(pmd_aligned, prot); + pud_thp_tests(pud_aligned, prot); + + hugetlb_basic_tests(pte_aligned, prot); + + /* + * Page table modifying tests. They need to hold + * proper page table lock. + */ + + ptep = pte_offset_map_lock(mm, pmdp, vaddr, &ptl); + pte_clear_tests(mm, ptep, pte_aligned, vaddr, prot); + pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot); + pte_unmap_unlock(ptep, ptl); + + ptl = pmd_lock(mm, pmdp); + pmd_clear_tests(mm, pmdp); + pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot, saved_ptep); + pmd_huge_tests(pmdp, pmd_aligned, prot); + pmd_populate_tests(mm, pmdp, saved_ptep); + spin_unlock(ptl); + + ptl = pud_lock(mm, pudp); + pud_clear_tests(mm, pudp); + pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot); + pud_huge_tests(pudp, pud_aligned, prot); + pud_populate_tests(mm, pudp, saved_pmdp); + spin_unlock(ptl); + + spin_lock(&mm->page_table_lock); + p4d_clear_tests(mm, p4dp); + pgd_clear_tests(mm, pgdp); + p4d_populate_tests(mm, p4dp, saved_pudp); + pgd_populate_tests(mm, pgdp, saved_p4dp); + spin_unlock(&mm->page_table_lock); + + p4d_free(mm, saved_p4dp); + pud_free(mm, saved_pudp); + pmd_free(mm, saved_pmdp); + pte_free(mm, saved_ptep); + + vm_area_free(vma); + mm_dec_nr_puds(mm); + mm_dec_nr_pmds(mm); + mm_dec_nr_ptes(mm); + mmdrop(mm); + return 0; +} +late_initcall(debug_vm_pgtable); |