Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
new file mode 100644
index 0000000..d6fbf28
--- /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);