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linux/mm/debug_vm_pgtable.c
Nicholas Piggin bbc180a5ad mm: HUGE_VMAP arch support cleanup 
This changes the awkward approach where architectures provide init
functions to determine which levels they can provide large mappings for,
to one where the arch is queried for each call.

This removes code and indirection, and allows constant-folding of dead
code for unsupported levels.

This also adds a prot argument to the arch query.  This is unused
currently but could help with some architectures (e.g., some powerpc
processors can't map uncacheable memory with large pages).

Link: https://lkml.kernel.org/r/20210317062402.533919-7-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30 11:20:40 -07:00

1107 lines
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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 <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_vmap_pmd_supported(prot))
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_vmap_pud_supported(prot))
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);
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