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debug_vm_pgtable.c
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debug_vm_pgtable.c
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// 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 <[email protected]>
*/
#define pr_fmt(fmt) "debug_vm_pgtable: [%-25s]: " fmt, __func__
#include <linux/gfp.h>
#include <linux/highmem.h>
#include <linux/hugetlb.h>
#include <linux/kernel.h>
#include <linux/kconfig.h>
#include <linux/memblock.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/mm_types.h>
#include <linux/module.h>
#include <linux/pfn_t.h>
#include <linux/printk.h>
#include <linux/pgtable.h>
#include <linux/random.h>
#include <linux/spinlock.h>
#include <linux/swap.h>
#include <linux/swapops.h>
#include <linux/start_kernel.h>
#include <linux/sched/mm.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
/*
* Please refer Documentation/mm/arch_pgtable_helpers.rst for the semantics
* expectations that are being validated here. All future changes in here
* or the documentation need to be in sync.
*
* On s390 platform, the lower 4 bits are used to identify given page table
* entry type. But these bits might affect the ability to clear entries with
* pxx_clear() because of how dynamic page table folding works on s390. So
* while loading up the entries do not change the lower 4 bits. It does not
* have affect any other platform. Also avoid the 62nd bit on ppc64 that is
* used to mark a pte entry.
*/
#define S390_SKIP_MASK GENMASK(3, 0)
#if __BITS_PER_LONG == 64
#define PPC64_SKIP_MASK GENMASK(62, 62)
#else
#define PPC64_SKIP_MASK 0x0
#endif
#define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK)
#define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK)
#define RANDOM_NZVALUE GENMASK(7, 0)
struct pgtable_debug_args {
struct mm_struct *mm;
struct vm_area_struct *vma;
pgd_t *pgdp;
p4d_t *p4dp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
p4d_t *start_p4dp;
pud_t *start_pudp;
pmd_t *start_pmdp;
pgtable_t start_ptep;
unsigned long vaddr;
pgprot_t page_prot;
pgprot_t page_prot_none;
bool is_contiguous_page;
unsigned long pud_pfn;
unsigned long pmd_pfn;
unsigned long pte_pfn;
unsigned long fixed_alignment;
unsigned long fixed_pgd_pfn;
unsigned long fixed_p4d_pfn;
unsigned long fixed_pud_pfn;
unsigned long fixed_pmd_pfn;
unsigned long fixed_pte_pfn;
};
static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx)
{
pgprot_t prot = vm_get_page_prot(idx);
pte_t pte = pfn_pte(args->fixed_pte_pfn, prot);
unsigned long val = idx, *ptr = &val;
pr_debug("Validating PTE basic (%pGv)\n", ptr);
/*
* This test needs to be executed after the given page table entry
* is created with pfn_pte() to make sure that vm_get_page_prot(idx)
* does not have the dirty bit enabled from the beginning. This is
* important for platforms like arm64 where (!PTE_RDONLY) indicate
* dirty bit being set.
*/
WARN_ON(pte_dirty(pte_wrprotect(pte)));
WARN_ON(!pte_same(pte, pte));
WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte))));
WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte))));
WARN_ON(!pte_write(pte_mkwrite(pte_wrprotect(pte))));
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 pgtable_debug_args *args)
{
struct page *page;
pte_t pte;
/*
* Architectures optimize set_pte_at by avoiding TLB flush.
* This requires set_pte_at to be not used to update an
* existing pte entry. Clear pte before we do set_pte_at
*
* flush_dcache_page() is called after set_pte_at() to clear
* PG_arch_1 for the page on ARM64. The page flag isn't cleared
* when it's released and page allocation check will fail when
* the page is allocated again. For architectures other than ARM64,
* the unexpected overhead of cache flushing is acceptable.
*/
page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
if (!page)
return;
pr_debug("Validating PTE advanced\n");
pte = pfn_pte(args->pte_pfn, args->page_prot);
set_pte_at(args->mm, args->vaddr, args->ptep, pte);
flush_dcache_page(page);
ptep_set_wrprotect(args->mm, args->vaddr, args->ptep);
pte = ptep_get(args->ptep);
WARN_ON(pte_write(pte));
ptep_get_and_clear(args->mm, args->vaddr, args->ptep);
pte = ptep_get(args->ptep);
WARN_ON(!pte_none(pte));
pte = pfn_pte(args->pte_pfn, args->page_prot);
pte = pte_wrprotect(pte);
pte = pte_mkclean(pte);
set_pte_at(args->mm, args->vaddr, args->ptep, pte);
flush_dcache_page(page);
pte = pte_mkwrite(pte);
pte = pte_mkdirty(pte);
ptep_set_access_flags(args->vma, args->vaddr, args->ptep, pte, 1);
pte = ptep_get(args->ptep);
WARN_ON(!(pte_write(pte) && pte_dirty(pte)));
ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1);
pte = ptep_get(args->ptep);
WARN_ON(!pte_none(pte));
pte = pfn_pte(args->pte_pfn, args->page_prot);
pte = pte_mkyoung(pte);
set_pte_at(args->mm, args->vaddr, args->ptep, pte);
flush_dcache_page(page);
ptep_test_and_clear_young(args->vma, args->vaddr, args->ptep);
pte = ptep_get(args->ptep);
WARN_ON(pte_young(pte));
ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1);
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx)
{
pgprot_t prot = vm_get_page_prot(idx);
unsigned long val = idx, *ptr = &val;
pmd_t pmd;
if (!has_transparent_hugepage())
return;
pr_debug("Validating PMD basic (%pGv)\n", ptr);
pmd = pfn_pmd(args->fixed_pmd_pfn, prot);
/*
* This test needs to be executed after the given page table entry
* is created with pfn_pmd() to make sure that vm_get_page_prot(idx)
* does not have the dirty bit enabled from the beginning. This is
* important for platforms like arm64 where (!PTE_RDONLY) indicate
* dirty bit being set.
*/
WARN_ON(pmd_dirty(pmd_wrprotect(pmd)));
WARN_ON(!pmd_same(pmd, pmd));
WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd))));
WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd))));
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 pgtable_debug_args *args)
{
struct page *page;
pmd_t pmd;
unsigned long vaddr = args->vaddr;
if (!has_transparent_hugepage())
return;
page = (args->pmd_pfn != ULONG_MAX) ? pfn_to_page(args->pmd_pfn) : NULL;
if (!page)
return;
/*
* flush_dcache_page() is called after set_pmd_at() to clear
* PG_arch_1 for the page on ARM64. The page flag isn't cleared
* when it's released and page allocation check will fail when
* the page is allocated again. For architectures other than ARM64,
* the unexpected overhead of cache flushing is acceptable.
*/
pr_debug("Validating PMD advanced\n");
/* Align the address wrt HPAGE_PMD_SIZE */
vaddr &= HPAGE_PMD_MASK;
pgtable_trans_huge_deposit(args->mm, args->pmdp, args->start_ptep);
pmd = pfn_pmd(args->pmd_pfn, args->page_prot);
set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
flush_dcache_page(page);
pmdp_set_wrprotect(args->mm, vaddr, args->pmdp);
pmd = READ_ONCE(*args->pmdp);
WARN_ON(pmd_write(pmd));
pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp);
pmd = READ_ONCE(*args->pmdp);
WARN_ON(!pmd_none(pmd));
pmd = pfn_pmd(args->pmd_pfn, args->page_prot);
pmd = pmd_wrprotect(pmd);
pmd = pmd_mkclean(pmd);
set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
flush_dcache_page(page);
pmd = pmd_mkwrite(pmd);
pmd = pmd_mkdirty(pmd);
pmdp_set_access_flags(args->vma, vaddr, args->pmdp, pmd, 1);
pmd = READ_ONCE(*args->pmdp);
WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
pmdp_huge_get_and_clear_full(args->vma, vaddr, args->pmdp, 1);
pmd = READ_ONCE(*args->pmdp);
WARN_ON(!pmd_none(pmd));
pmd = pmd_mkhuge(pfn_pmd(args->pmd_pfn, args->page_prot));
pmd = pmd_mkyoung(pmd);
set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
flush_dcache_page(page);
pmdp_test_and_clear_young(args->vma, vaddr, args->pmdp);
pmd = READ_ONCE(*args->pmdp);
WARN_ON(pmd_young(pmd));
/* Clear the pte entries */
pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp);
pgtable_trans_huge_withdraw(args->mm, args->pmdp);
}
static void __init pmd_leaf_tests(struct pgtable_debug_args *args)
{
pmd_t pmd;
if (!has_transparent_hugepage())
return;
pr_debug("Validating PMD leaf\n");
pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
/*
* PMD based THP is a leaf entry.
*/
pmd = pmd_mkhuge(pmd);
WARN_ON(!pmd_leaf(pmd));
}
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx)
{
pgprot_t prot = vm_get_page_prot(idx);
unsigned long val = idx, *ptr = &val;
pud_t pud;
if (!has_transparent_hugepage())
return;
pr_debug("Validating PUD basic (%pGv)\n", ptr);
pud = pfn_pud(args->fixed_pud_pfn, prot);
/*
* This test needs to be executed after the given page table entry
* is created with pfn_pud() to make sure that vm_get_page_prot(idx)
* does not have the dirty bit enabled from the beginning. This is
* important for platforms like arm64 where (!PTE_RDONLY) indicate
* dirty bit being set.
*/
WARN_ON(pud_dirty(pud_wrprotect(pud)));
WARN_ON(!pud_same(pud, pud));
WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud))));
WARN_ON(!pud_dirty(pud_mkdirty(pud_mkclean(pud))));
WARN_ON(pud_dirty(pud_mkclean(pud_mkdirty(pud))));
WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud))));
WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud))));
WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud))));
WARN_ON(pud_dirty(pud_wrprotect(pud_mkclean(pud))));
WARN_ON(!pud_dirty(pud_wrprotect(pud_mkdirty(pud))));
if (mm_pmd_folded(args->mm))
return;
/*
* A huge page does not point to next level page table
* entry. Hence this must qualify as pud_bad().
*/
WARN_ON(!pud_bad(pud_mkhuge(pud)));
}
static void __init pud_advanced_tests(struct pgtable_debug_args *args)
{
struct page *page;
unsigned long vaddr = args->vaddr;
pud_t pud;
if (!has_transparent_hugepage())
return;
page = (args->pud_pfn != ULONG_MAX) ? pfn_to_page(args->pud_pfn) : NULL;
if (!page)
return;
/*
* flush_dcache_page() is called after set_pud_at() to clear
* PG_arch_1 for the page on ARM64. The page flag isn't cleared
* when it's released and page allocation check will fail when
* the page is allocated again. For architectures other than ARM64,
* the unexpected overhead of cache flushing is acceptable.
*/
pr_debug("Validating PUD advanced\n");
/* Align the address wrt HPAGE_PUD_SIZE */
vaddr &= HPAGE_PUD_MASK;
pud = pfn_pud(args->pud_pfn, args->page_prot);
set_pud_at(args->mm, vaddr, args->pudp, pud);
flush_dcache_page(page);
pudp_set_wrprotect(args->mm, vaddr, args->pudp);
pud = READ_ONCE(*args->pudp);
WARN_ON(pud_write(pud));
#ifndef __PAGETABLE_PMD_FOLDED
pudp_huge_get_and_clear(args->mm, vaddr, args->pudp);
pud = READ_ONCE(*args->pudp);
WARN_ON(!pud_none(pud));
#endif /* __PAGETABLE_PMD_FOLDED */
pud = pfn_pud(args->pud_pfn, args->page_prot);
pud = pud_wrprotect(pud);
pud = pud_mkclean(pud);
set_pud_at(args->mm, vaddr, args->pudp, pud);
flush_dcache_page(page);
pud = pud_mkwrite(pud);
pud = pud_mkdirty(pud);
pudp_set_access_flags(args->vma, vaddr, args->pudp, pud, 1);
pud = READ_ONCE(*args->pudp);
WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
#ifndef __PAGETABLE_PMD_FOLDED
pudp_huge_get_and_clear_full(args->mm, vaddr, args->pudp, 1);
pud = READ_ONCE(*args->pudp);
WARN_ON(!pud_none(pud));
#endif /* __PAGETABLE_PMD_FOLDED */
pud = pfn_pud(args->pud_pfn, args->page_prot);
pud = pud_mkyoung(pud);
set_pud_at(args->mm, vaddr, args->pudp, pud);
flush_dcache_page(page);
pudp_test_and_clear_young(args->vma, vaddr, args->pudp);
pud = READ_ONCE(*args->pudp);
WARN_ON(pud_young(pud));
pudp_huge_get_and_clear(args->mm, vaddr, args->pudp);
}
static void __init pud_leaf_tests(struct pgtable_debug_args *args)
{
pud_t pud;
if (!has_transparent_hugepage())
return;
pr_debug("Validating PUD leaf\n");
pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
/*
* PUD based THP is a leaf entry.
*/
pud = pud_mkhuge(pud);
WARN_ON(!pud_leaf(pud));
}
#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { }
static void __init pud_advanced_tests(struct pgtable_debug_args *args) { }
static void __init pud_leaf_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx) { }
static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { }
static void __init pmd_advanced_tests(struct pgtable_debug_args *args) { }
static void __init pud_advanced_tests(struct pgtable_debug_args *args) { }
static void __init pmd_leaf_tests(struct pgtable_debug_args *args) { }
static void __init pud_leaf_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
static void __init pmd_huge_tests(struct pgtable_debug_args *args)
{
pmd_t pmd;
if (!arch_vmap_pmd_supported(args->page_prot) ||
args->fixed_alignment < PMD_SIZE)
return;
pr_debug("Validating PMD huge\n");
/*
* X86 defined pmd_set_huge() verifies that the given
* PMD is not a populated non-leaf entry.
*/
WRITE_ONCE(*args->pmdp, __pmd(0));
WARN_ON(!pmd_set_huge(args->pmdp, __pfn_to_phys(args->fixed_pmd_pfn), args->page_prot));
WARN_ON(!pmd_clear_huge(args->pmdp));
pmd = READ_ONCE(*args->pmdp);
WARN_ON(!pmd_none(pmd));
}
static void __init pud_huge_tests(struct pgtable_debug_args *args)
{
pud_t pud;
if (!arch_vmap_pud_supported(args->page_prot) ||
args->fixed_alignment < PUD_SIZE)
return;
pr_debug("Validating PUD huge\n");
/*
* X86 defined pud_set_huge() verifies that the given
* PUD is not a populated non-leaf entry.
*/
WRITE_ONCE(*args->pudp, __pud(0));
WARN_ON(!pud_set_huge(args->pudp, __pfn_to_phys(args->fixed_pud_pfn), args->page_prot));
WARN_ON(!pud_clear_huge(args->pudp));
pud = READ_ONCE(*args->pudp);
WARN_ON(!pud_none(pud));
}
#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
static void __init pmd_huge_tests(struct pgtable_debug_args *args) { }
static void __init pud_huge_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
static void __init p4d_basic_tests(struct pgtable_debug_args *args)
{
p4d_t p4d;
pr_debug("Validating P4D basic\n");
memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
WARN_ON(!p4d_same(p4d, p4d));
}
static void __init pgd_basic_tests(struct pgtable_debug_args *args)
{
pgd_t pgd;
pr_debug("Validating PGD basic\n");
memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
WARN_ON(!pgd_same(pgd, pgd));
}
#ifndef __PAGETABLE_PUD_FOLDED
static void __init pud_clear_tests(struct pgtable_debug_args *args)
{
pud_t pud = READ_ONCE(*args->pudp);
if (mm_pmd_folded(args->mm))
return;
pr_debug("Validating PUD clear\n");
pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
WRITE_ONCE(*args->pudp, pud);
pud_clear(args->pudp);
pud = READ_ONCE(*args->pudp);
WARN_ON(!pud_none(pud));
}
static void __init pud_populate_tests(struct pgtable_debug_args *args)
{
pud_t pud;
if (mm_pmd_folded(args->mm))
return;
pr_debug("Validating PUD populate\n");
/*
* This entry points to next level page table page.
* Hence this must not qualify as pud_bad().
*/
pud_populate(args->mm, args->pudp, args->start_pmdp);
pud = READ_ONCE(*args->pudp);
WARN_ON(pud_bad(pud));
}
#else /* !__PAGETABLE_PUD_FOLDED */
static void __init pud_clear_tests(struct pgtable_debug_args *args) { }
static void __init pud_populate_tests(struct pgtable_debug_args *args) { }
#endif /* PAGETABLE_PUD_FOLDED */
#ifndef __PAGETABLE_P4D_FOLDED
static void __init p4d_clear_tests(struct pgtable_debug_args *args)
{
p4d_t p4d = READ_ONCE(*args->p4dp);
if (mm_pud_folded(args->mm))
return;
pr_debug("Validating P4D clear\n");
p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
WRITE_ONCE(*args->p4dp, p4d);
p4d_clear(args->p4dp);
p4d = READ_ONCE(*args->p4dp);
WARN_ON(!p4d_none(p4d));
}
static void __init p4d_populate_tests(struct pgtable_debug_args *args)
{
p4d_t p4d;
if (mm_pud_folded(args->mm))
return;
pr_debug("Validating P4D populate\n");
/*
* This entry points to next level page table page.
* Hence this must not qualify as p4d_bad().
*/
pud_clear(args->pudp);
p4d_clear(args->p4dp);
p4d_populate(args->mm, args->p4dp, args->start_pudp);
p4d = READ_ONCE(*args->p4dp);
WARN_ON(p4d_bad(p4d));
}
static void __init pgd_clear_tests(struct pgtable_debug_args *args)
{
pgd_t pgd = READ_ONCE(*(args->pgdp));
if (mm_p4d_folded(args->mm))
return;
pr_debug("Validating PGD clear\n");
pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
WRITE_ONCE(*args->pgdp, pgd);
pgd_clear(args->pgdp);
pgd = READ_ONCE(*args->pgdp);
WARN_ON(!pgd_none(pgd));
}
static void __init pgd_populate_tests(struct pgtable_debug_args *args)
{
pgd_t pgd;
if (mm_p4d_folded(args->mm))
return;
pr_debug("Validating PGD populate\n");
/*
* This entry points to next level page table page.
* Hence this must not qualify as pgd_bad().
*/
p4d_clear(args->p4dp);
pgd_clear(args->pgdp);
pgd_populate(args->mm, args->pgdp, args->start_p4dp);
pgd = READ_ONCE(*args->pgdp);
WARN_ON(pgd_bad(pgd));
}
#else /* !__PAGETABLE_P4D_FOLDED */
static void __init p4d_clear_tests(struct pgtable_debug_args *args) { }
static void __init pgd_clear_tests(struct pgtable_debug_args *args) { }
static void __init p4d_populate_tests(struct pgtable_debug_args *args) { }
static void __init pgd_populate_tests(struct pgtable_debug_args *args) { }
#endif /* PAGETABLE_P4D_FOLDED */
static void __init pte_clear_tests(struct pgtable_debug_args *args)
{
struct page *page;
pte_t pte = pfn_pte(args->pte_pfn, args->page_prot);
page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
if (!page)
return;
/*
* flush_dcache_page() is called after set_pte_at() to clear
* PG_arch_1 for the page on ARM64. The page flag isn't cleared
* when it's released and page allocation check will fail when
* the page is allocated again. For architectures other than ARM64,
* the unexpected overhead of cache flushing is acceptable.
*/
pr_debug("Validating PTE clear\n");
#ifndef CONFIG_RISCV
pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
#endif
set_pte_at(args->mm, args->vaddr, args->ptep, pte);
flush_dcache_page(page);
barrier();
ptep_clear(args->mm, args->vaddr, args->ptep);
pte = ptep_get(args->ptep);
WARN_ON(!pte_none(pte));
}
static void __init pmd_clear_tests(struct pgtable_debug_args *args)
{
pmd_t pmd = READ_ONCE(*args->pmdp);
pr_debug("Validating PMD clear\n");
pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
WRITE_ONCE(*args->pmdp, pmd);
pmd_clear(args->pmdp);
pmd = READ_ONCE(*args->pmdp);
WARN_ON(!pmd_none(pmd));
}
static void __init pmd_populate_tests(struct pgtable_debug_args *args)
{
pmd_t pmd;
pr_debug("Validating PMD populate\n");
/*
* This entry points to next level page table page.
* Hence this must not qualify as pmd_bad().
*/
pmd_populate(args->mm, args->pmdp, args->start_ptep);
pmd = READ_ONCE(*args->pmdp);
WARN_ON(pmd_bad(pmd));
}
static void __init pte_special_tests(struct pgtable_debug_args *args)
{
pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL))
return;
pr_debug("Validating PTE special\n");
WARN_ON(!pte_special(pte_mkspecial(pte)));
}
static void __init pte_protnone_tests(struct pgtable_debug_args *args)
{
pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot_none);
if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
return;
pr_debug("Validating PTE protnone\n");
WARN_ON(!pte_protnone(pte));
WARN_ON(!pte_present(pte));
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static void __init pmd_protnone_tests(struct pgtable_debug_args *args)
{
pmd_t pmd;
if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
return;
if (!has_transparent_hugepage())
return;
pr_debug("Validating PMD protnone\n");
pmd = pmd_mkhuge(pfn_pmd(args->fixed_pmd_pfn, args->page_prot_none));
WARN_ON(!pmd_protnone(pmd));
WARN_ON(!pmd_present(pmd));
}
#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
static void __init pmd_protnone_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
static void __init pte_devmap_tests(struct pgtable_debug_args *args)
{
pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
pr_debug("Validating PTE devmap\n");
WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static void __init pmd_devmap_tests(struct pgtable_debug_args *args)
{
pmd_t pmd;
if (!has_transparent_hugepage())
return;
pr_debug("Validating PMD devmap\n");
pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
}
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static void __init pud_devmap_tests(struct pgtable_debug_args *args)
{
pud_t pud;
if (!has_transparent_hugepage())
return;
pr_debug("Validating PUD devmap\n");
pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
}
#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#else
static void __init pte_devmap_tests(struct pgtable_debug_args *args) { }
static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
static void __init pte_soft_dirty_tests(struct pgtable_debug_args *args)
{
pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
return;
pr_debug("Validating PTE soft dirty\n");
WARN_ON(!pte_soft_dirty(pte_mksoft_dirty(pte)));
WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte)));
}
static void __init pte_swap_soft_dirty_tests(struct pgtable_debug_args *args)
{
pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
return;
pr_debug("Validating PTE swap soft dirty\n");
WARN_ON(!pte_swp_soft_dirty(pte_swp_mksoft_dirty(pte)));
WARN_ON(pte_swp_soft_dirty(pte_swp_clear_soft_dirty(pte)));
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args)
{
pmd_t pmd;
if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
return;
if (!has_transparent_hugepage())
return;
pr_debug("Validating PMD soft dirty\n");
pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd)));
WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd)));
}
static void __init pmd_swap_soft_dirty_tests(struct pgtable_debug_args *args)
{
pmd_t pmd;
if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) ||
!IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION))
return;
if (!has_transparent_hugepage())
return;
pr_debug("Validating PMD swap soft dirty\n");
pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
}
#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args) { }
static void __init pmd_swap_soft_dirty_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
static void __init pte_swap_exclusive_tests(struct pgtable_debug_args *args)
{
unsigned long max_swap_offset;
swp_entry_t entry, entry2;
pte_t pte;
pr_debug("Validating PTE swap exclusive\n");
/* See generic_max_swapfile_size(): probe the maximum offset */
max_swap_offset = swp_offset(pte_to_swp_entry(swp_entry_to_pte(swp_entry(0, ~0UL))));
/* Create a swp entry with all possible bits set */
entry = swp_entry((1 << MAX_SWAPFILES_SHIFT) - 1, max_swap_offset);
pte = swp_entry_to_pte(entry);
WARN_ON(pte_swp_exclusive(pte));
WARN_ON(!is_swap_pte(pte));
entry2 = pte_to_swp_entry(pte);
WARN_ON(memcmp(&entry, &entry2, sizeof(entry)));
pte = pte_swp_mkexclusive(pte);
WARN_ON(!pte_swp_exclusive(pte));
WARN_ON(!is_swap_pte(pte));
WARN_ON(pte_swp_soft_dirty(pte));
entry2 = pte_to_swp_entry(pte);
WARN_ON(memcmp(&entry, &entry2, sizeof(entry)));
pte = pte_swp_clear_exclusive(pte);
WARN_ON(pte_swp_exclusive(pte));
WARN_ON(!is_swap_pte(pte));
entry2 = pte_to_swp_entry(pte);
WARN_ON(memcmp(&entry, &entry2, sizeof(entry)));
}
static void __init pte_swap_tests(struct pgtable_debug_args *args)
{
swp_entry_t swp;
pte_t pte;
pr_debug("Validating PTE swap\n");
pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
swp = __pte_to_swp_entry(pte);
pte = __swp_entry_to_pte(swp);
WARN_ON(args->fixed_pte_pfn != pte_pfn(pte));
}
#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
static void __init pmd_swap_tests(struct pgtable_debug_args *args)
{
swp_entry_t swp;
pmd_t pmd;
if (!has_transparent_hugepage())
return;
pr_debug("Validating PMD swap\n");
pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
swp = __pmd_to_swp_entry(pmd);
pmd = __swp_entry_to_pmd(swp);
WARN_ON(args->fixed_pmd_pfn != pmd_pfn(pmd));
}
#else /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */
static void __init pmd_swap_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
static void __init swap_migration_tests(struct pgtable_debug_args *args)
{
struct page *page;
swp_entry_t swp;
if (!IS_ENABLED(CONFIG_MIGRATION))
return;
/*
* swap_migration_tests() requires a dedicated page as it needs to
* be locked before creating a migration entry from it. Locking the
* page that actually maps kernel text ('start_kernel') can be real
* problematic. Lets use the allocated page explicitly for this
* purpose.
*/
page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
if (!page)
return;
pr_debug("Validating swap migration\n");
/*
* make_[readable|writable]_migration_entry() expects given page to
* be locked, otherwise it stumbles upon a BUG_ON().
*/
__SetPageLocked(page);
swp = make_writable_migration_entry(page_to_pfn(page));
WARN_ON(!is_migration_entry(swp));
WARN_ON(!is_writable_migration_entry(swp));
swp = make_readable_migration_entry(swp_offset(swp));
WARN_ON(!is_migration_entry(swp));
WARN_ON(is_writable_migration_entry(swp));
swp = make_readable_migration_entry(page_to_pfn(page));
WARN_ON(!is_migration_entry(swp));
WARN_ON(is_writable_migration_entry(swp));
__ClearPageLocked(page);
}
#ifdef CONFIG_HUGETLB_PAGE
static void __init hugetlb_basic_tests(struct pgtable_debug_args *args)
{
struct page *page;
pte_t pte;
pr_debug("Validating HugeTLB basic\n");
/*
* Accessing the page associated with the pfn is safe here,
* as it was previously derived from a real kernel symbol.
*/
page = pfn_to_page(args->fixed_pmd_pfn);
pte = mk_huge_pte(page, args->page_prot);
WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte)));
WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte))));
WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte))));
#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
pte = pfn_pte(args->fixed_pmd_pfn, args->page_prot);
WARN_ON(!pte_huge(pte_mkhuge(pte)));
#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
}
#else /* !CONFIG_HUGETLB_PAGE */
static void __init hugetlb_basic_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_HUGETLB_PAGE */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static void __init pmd_thp_tests(struct pgtable_debug_args *args)
{
pmd_t pmd;
if (!has_transparent_hugepage())
return;
pr_debug("Validating PMD based THP\n");
/*
* pmd_trans_huge() and pmd_present() must return positive after
* MMU invalidation with pmd_mkinvalid(). This behavior is an
* optimization for transparent huge page. pmd_trans_huge() must
* be true if pmd_page() returns a valid THP to avoid taking the
* pmd_lock when others walk over non transhuge pmds (i.e. there
* are no THP allocated). Especially when splitting a THP and
* removing the present bit from the pmd, pmd_trans_huge() still
* needs to return true. pmd_present() should be true whenever
* pmd_trans_huge() returns true.
*/
pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd)));
#ifndef __HAVE_ARCH_PMDP_INVALIDATE
WARN_ON(!pmd_trans_huge(pmd_mkinvalid(pmd_mkhuge(pmd))));
WARN_ON(!pmd_present(pmd_mkinvalid(pmd_mkhuge(pmd))));
#endif /* __HAVE_ARCH_PMDP_INVALIDATE */
}
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static void __init pud_thp_tests(struct pgtable_debug_args *args)
{
pud_t pud;
if (!has_transparent_hugepage())
return;
pr_debug("Validating PUD based THP\n");
pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
WARN_ON(!pud_trans_huge(pud_mkhuge(pud)));
/*
* pud_mkinvalid() has been dropped for now. Enable back
* these tests when it comes back with a modified pud_present().
*
* WARN_ON(!pud_trans_huge(pud_mkinvalid(pud_mkhuge(pud))));
* WARN_ON(!pud_present(pud_mkinvalid(pud_mkhuge(pud))));
*/
}
#else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
static void __init pud_thp_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
#else /* !CONFIG_TRANSPARENT_HUGEPAGE */
static void __init pmd_thp_tests(struct pgtable_debug_args *args) { }
static void __init pud_thp_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */