// 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)); } 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]; pmd_t pmd = pfn_pmd(pfn, prot); unsigned long val = idx, *ptr = &val; if (!has_transparent_hugepage()) return; pr_debug("Validating PMD basic (%pGv)\n", ptr); /* * 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 = pfn_pmd(pfn, prot); if (!has_transparent_hugepage()) return; pr_debug("Validating PMD advanced\n"); /* Align the address wrt HPAGE_PMD_SIZE */ vaddr = (vaddr & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE; 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 = pfn_pmd(pfn, prot); pr_debug("Validating PMD leaf\n"); /* * 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 = pfn_pmd(pfn, prot); if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) return; pr_debug("Validating PMD saved write\n"); 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]; pud_t pud = pfn_pud(pfn, prot); unsigned long val = idx, *ptr = &val; if (!has_transparent_hugepage()) return; pr_debug("Validating PUD basic (%pGv)\n", ptr); /* * 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 = pfn_pud(pfn, prot); if (!has_transparent_hugepage()) return; pr_debug("Validating PUD advanced\n"); /* Align the address wrt HPAGE_PUD_SIZE */ vaddr = (vaddr & HPAGE_PUD_MASK) + HPAGE_PUD_SIZE; 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 = pfn_pud(pfn, prot); pr_debug("Validating PUD leaf\n"); /* * 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 = pmd_mkhuge(pfn_pmd(pfn, prot)); if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) return; pr_debug("Validating PMD protnone\n"); 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 = pfn_pmd(pfn, prot); pr_debug("Validating PMD devmap\n"); 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); pr_debug("Validating PUD devmap\n"); 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 = pfn_pmd(pfn, prot); if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) return; pr_debug("Validating PMD soft dirty\n"); 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; pr_debug("Validating PMD swap soft dirty\n"); 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; 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);