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linux-stable/mm/debug_vm_pgtable.c
Aneesh Kumar K.V (IBM) 720da1e593 mm/debug_vm_pgtable: fix BUG_ON with pud advanced test 
Architectures like powerpc add debug checks to ensure we find only devmap
PUD pte entries.  These debug checks are only done with CONFIG_DEBUG_VM. 
This patch marks the ptes used for PUD advanced test devmap pte entries so
that we don't hit on debug checks on architecture like ppc64 as below.

WARNING: CPU: 2 PID: 1 at arch/powerpc/mm/book3s64/radix_pgtable.c:1382 radix__pud_hugepage_update+0x38/0x138
....
NIP [c0000000000a7004] radix__pud_hugepage_update+0x38/0x138
LR [c0000000000a77a8] radix__pudp_huge_get_and_clear+0x28/0x60
Call Trace:
[c000000004a2f950] [c000000004a2f9a0] 0xc000000004a2f9a0 (unreliable)
[c000000004a2f980] [000d34c100000000] 0xd34c100000000
[c000000004a2f9a0] [c00000000206ba98] pud_advanced_tests+0x118/0x334
[c000000004a2fa40] [c00000000206db34] debug_vm_pgtable+0xcbc/0x1c48
[c000000004a2fc10] [c00000000000fd28] do_one_initcall+0x60/0x388

Also

 kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:202!
 ....

 NIP [c000000000096510] pudp_huge_get_and_clear_full+0x98/0x174
 LR [c00000000206bb34] pud_advanced_tests+0x1b4/0x334
 Call Trace:
 [c000000004a2f950] [000d34c100000000] 0xd34c100000000 (unreliable)
 [c000000004a2f9a0] [c00000000206bb34] pud_advanced_tests+0x1b4/0x334
 [c000000004a2fa40] [c00000000206db34] debug_vm_pgtable+0xcbc/0x1c48
 [c000000004a2fc10] [c00000000000fd28] do_one_initcall+0x60/0x388

Link: https://lkml.kernel.org/r/20240129060022.68044-1-aneesh.kumar@kernel.org
Fixes: 27af67f356 ("powerpc/book3s64/mm: enable transparent pud hugepage")
Signed-off-by: Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-23 17:27:13 -08:00

1419 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/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), args->vma)));
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, args->vma))));
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");
if (WARN_ON(!args->ptep))
return;
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, args->vma);
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), args->vma)));
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, args->vma))));
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, args->vma);
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_pud_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_pud_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);
/*
* Some architectures have debug checks to make sure
* huge pud mapping are only found with devmap entries
* For now test with only devmap entries.
*/
pud = pud_mkdevmap(pud);
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_mkdevmap(pud);
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->vma, 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_mkdevmap(pud);
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_pud_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");
if (WARN_ON(!args->ptep))
return;
#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_pud_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(arch_make_huge_pte(pte, PMD_SHIFT, VM_ACCESS_FLAGS)));
#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_pud_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 */
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 void __init destroy_args(struct pgtable_debug_args *args)
{
struct page *page = NULL;
/* Free (huge) page */
if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
has_transparent_pud_hugepage() &&
args->pud_pfn != ULONG_MAX) {
if (args->is_contiguous_page) {
free_contig_range(args->pud_pfn,
(1 << (HPAGE_PUD_SHIFT - PAGE_SHIFT)));
} else {
page = pfn_to_page(args->pud_pfn);
__free_pages(page, HPAGE_PUD_SHIFT - PAGE_SHIFT);
}
args->pud_pfn = ULONG_MAX;
args->pmd_pfn = ULONG_MAX;
args->pte_pfn = ULONG_MAX;
}
if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
has_transparent_hugepage() &&
args->pmd_pfn != ULONG_MAX) {
if (args->is_contiguous_page) {
free_contig_range(args->pmd_pfn, (1 << HPAGE_PMD_ORDER));
} else {
page = pfn_to_page(args->pmd_pfn);
__free_pages(page, HPAGE_PMD_ORDER);
}
args->pmd_pfn = ULONG_MAX;
args->pte_pfn = ULONG_MAX;
}
if (args->pte_pfn != ULONG_MAX) {
page = pfn_to_page(args->pte_pfn);
__free_page(page);
args->pte_pfn = ULONG_MAX;
}
/* Free page table entries */
if (args->start_ptep) {
pte_free(args->mm, args->start_ptep);
mm_dec_nr_ptes(args->mm);
}
if (args->start_pmdp) {
pmd_free(args->mm, args->start_pmdp);
mm_dec_nr_pmds(args->mm);
}
if (args->start_pudp) {
pud_free(args->mm, args->start_pudp);
mm_dec_nr_puds(args->mm);
}
if (args->start_p4dp)
p4d_free(args->mm, args->start_p4dp);
/* Free vma and mm struct */
if (args->vma)
vm_area_free(args->vma);
if (args->mm)
mmdrop(args->mm);
}
static struct page * __init
debug_vm_pgtable_alloc_huge_page(struct pgtable_debug_args *args, int order)
{
struct page *page = NULL;
#ifdef CONFIG_CONTIG_ALLOC
if (order > MAX_PAGE_ORDER) {
page = alloc_contig_pages((1 << order), GFP_KERNEL,
first_online_node, NULL);
if (page) {
args->is_contiguous_page = true;
return page;
}
}
#endif
if (order <= MAX_PAGE_ORDER)
page = alloc_pages(GFP_KERNEL, order);
return page;
}
/*
* Check if a physical memory range described by <pstart, pend> contains
* an area that is of size psize, and aligned to psize.
*
* Don't use address 0, an all-zeroes physical address might mask bugs, and
* it's not used on x86.
*/
static void __init phys_align_check(phys_addr_t pstart,
phys_addr_t pend, unsigned long psize,
phys_addr_t *physp, unsigned long *alignp)
{
phys_addr_t aligned_start, aligned_end;
if (pstart == 0)
pstart = PAGE_SIZE;
aligned_start = ALIGN(pstart, psize);
aligned_end = aligned_start + psize;
if (aligned_end > aligned_start && aligned_end <= pend) {
*alignp = psize;
*physp = aligned_start;
}
}
static void __init init_fixed_pfns(struct pgtable_debug_args *args)
{
u64 idx;
phys_addr_t phys, pstart, pend;
/*
* Initialize the fixed pfns. To do this, try to find a
* valid physical range, preferably aligned to PUD_SIZE,
* but settling for aligned to PMD_SIZE as a fallback. If
* neither of those is found, use the physical address of
* the start_kernel symbol.
*
* The memory doesn't need to be allocated, it just needs to exist
* as usable memory. It won't be touched.
*
* The alignment is recorded, and can be checked to see if we
* can run the tests that require an actual valid physical
* address range on some architectures ({pmd,pud}_huge_test
* on x86).
*/
phys = __pa_symbol(&start_kernel);
args->fixed_alignment = PAGE_SIZE;
for_each_mem_range(idx, &pstart, &pend) {
/* First check for a PUD-aligned area */
phys_align_check(pstart, pend, PUD_SIZE, &phys,
&args->fixed_alignment);
/* If a PUD-aligned area is found, we're done */
if (args->fixed_alignment == PUD_SIZE)
break;
/*
* If no PMD-aligned area found yet, check for one,
* but continue the loop to look for a PUD-aligned area.
*/
if (args->fixed_alignment < PMD_SIZE)
phys_align_check(pstart, pend, PMD_SIZE, &phys,
&args->fixed_alignment);
}
args->fixed_pgd_pfn = __phys_to_pfn(phys & PGDIR_MASK);
args->fixed_p4d_pfn = __phys_to_pfn(phys & P4D_MASK);
args->fixed_pud_pfn = __phys_to_pfn(phys & PUD_MASK);
args->fixed_pmd_pfn = __phys_to_pfn(phys & PMD_MASK);
args->fixed_pte_pfn = __phys_to_pfn(phys & PAGE_MASK);
WARN_ON(!pfn_valid(args->fixed_pte_pfn));
}
static int __init init_args(struct pgtable_debug_args *args)
{
struct page *page = NULL;
int ret = 0;
/*
* Initialize the debugging data.
*
* vm_get_page_prot(VM_NONE) or vm_get_page_prot(VM_SHARED|VM_NONE)
* will help create page table entries with PROT_NONE permission as
* required for pxx_protnone_tests().
*/
memset(args, 0, sizeof(*args));
args->vaddr = get_random_vaddr();
args->page_prot = vm_get_page_prot(VM_ACCESS_FLAGS);
args->page_prot_none = vm_get_page_prot(VM_NONE);
args->is_contiguous_page = false;
args->pud_pfn = ULONG_MAX;
args->pmd_pfn = ULONG_MAX;
args->pte_pfn = ULONG_MAX;
args->fixed_pgd_pfn = ULONG_MAX;
args->fixed_p4d_pfn = ULONG_MAX;
args->fixed_pud_pfn = ULONG_MAX;
args->fixed_pmd_pfn = ULONG_MAX;
args->fixed_pte_pfn = ULONG_MAX;
/* Allocate mm and vma */
args->mm = mm_alloc();
if (!args->mm) {
pr_err("Failed to allocate mm struct\n");
ret = -ENOMEM;
goto error;
}
args->vma = vm_area_alloc(args->mm);
if (!args->vma) {
pr_err("Failed to allocate vma\n");
ret = -ENOMEM;
goto error;
}
/*
* Allocate page table entries. They will be modified in the tests.
* Lets save the page table entries so that they can be released
* when the tests are completed.
*/
args->pgdp = pgd_offset(args->mm, args->vaddr);
args->p4dp = p4d_alloc(args->mm, args->pgdp, args->vaddr);
if (!args->p4dp) {
pr_err("Failed to allocate p4d entries\n");
ret = -ENOMEM;
goto error;
}
args->start_p4dp = p4d_offset(args->pgdp, 0UL);
WARN_ON(!args->start_p4dp);
args->pudp = pud_alloc(args->mm, args->p4dp, args->vaddr);
if (!args->pudp) {
pr_err("Failed to allocate pud entries\n");
ret = -ENOMEM;
goto error;
}
args->start_pudp = pud_offset(args->p4dp, 0UL);
WARN_ON(!args->start_pudp);
args->pmdp = pmd_alloc(args->mm, args->pudp, args->vaddr);
if (!args->pmdp) {
pr_err("Failed to allocate pmd entries\n");
ret = -ENOMEM;
goto error;
}
args->start_pmdp = pmd_offset(args->pudp, 0UL);
WARN_ON(!args->start_pmdp);
if (pte_alloc(args->mm, args->pmdp)) {
pr_err("Failed to allocate pte entries\n");
ret = -ENOMEM;
goto error;
}
args->start_ptep = pmd_pgtable(READ_ONCE(*args->pmdp));
WARN_ON(!args->start_ptep);
init_fixed_pfns(args);
/*
* Allocate (huge) pages because some of the tests need to access
* the data in the pages. The corresponding tests will be skipped
* if we fail to allocate (huge) pages.
*/
if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
has_transparent_pud_hugepage()) {
page = debug_vm_pgtable_alloc_huge_page(args,
HPAGE_PUD_SHIFT - PAGE_SHIFT);
if (page) {
args->pud_pfn = page_to_pfn(page);
args->pmd_pfn = args->pud_pfn;
args->pte_pfn = args->pud_pfn;
return 0;
}
}
if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
has_transparent_hugepage()) {
page = debug_vm_pgtable_alloc_huge_page(args, HPAGE_PMD_ORDER);
if (page) {
args->pmd_pfn = page_to_pfn(page);
args->pte_pfn = args->pmd_pfn;
return 0;
}
}
page = alloc_page(GFP_KERNEL);
if (page)
args->pte_pfn = page_to_pfn(page);
return 0;
error:
destroy_args(args);
return ret;
}
static int __init debug_vm_pgtable(void)
{
struct pgtable_debug_args args;
spinlock_t *ptl = NULL;
int idx, ret;
pr_info("Validating architecture page table helpers\n");
ret = init_args(&args);
if (ret)
return ret;
/*
* Iterate over each possible vm_flags 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.
*
* Protection based vm_flags combinations are always linear
* and increasing i.e starting from VM_NONE and going up to
* (VM_SHARED | READ | WRITE | EXEC).
*/
#define VM_FLAGS_START (VM_NONE)
#define VM_FLAGS_END (VM_SHARED | VM_EXEC | VM_WRITE | VM_READ)
for (idx = VM_FLAGS_START; idx <= VM_FLAGS_END; idx++) {
pte_basic_tests(&args, idx);
pmd_basic_tests(&args, idx);
pud_basic_tests(&args, 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(&args);
pgd_basic_tests(&args);
pmd_leaf_tests(&args);
pud_leaf_tests(&args);
pte_special_tests(&args);
pte_protnone_tests(&args);
pmd_protnone_tests(&args);
pte_devmap_tests(&args);
pmd_devmap_tests(&args);
pud_devmap_tests(&args);
pte_soft_dirty_tests(&args);
pmd_soft_dirty_tests(&args);
pte_swap_soft_dirty_tests(&args);
pmd_swap_soft_dirty_tests(&args);
pte_swap_exclusive_tests(&args);
pte_swap_tests(&args);
pmd_swap_tests(&args);
swap_migration_tests(&args);
pmd_thp_tests(&args);
pud_thp_tests(&args);
hugetlb_basic_tests(&args);
/*
* Page table modifying tests. They need to hold
* proper page table lock.
*/
args.ptep = pte_offset_map_lock(args.mm, args.pmdp, args.vaddr, &ptl);
pte_clear_tests(&args);
pte_advanced_tests(&args);
if (args.ptep)
pte_unmap_unlock(args.ptep, ptl);
ptl = pmd_lock(args.mm, args.pmdp);
pmd_clear_tests(&args);
pmd_advanced_tests(&args);
pmd_huge_tests(&args);
pmd_populate_tests(&args);
spin_unlock(ptl);
ptl = pud_lock(args.mm, args.pudp);
pud_clear_tests(&args);
pud_advanced_tests(&args);
pud_huge_tests(&args);
pud_populate_tests(&args);
spin_unlock(ptl);
spin_lock(&(args.mm->page_table_lock));
p4d_clear_tests(&args);
pgd_clear_tests(&args);
p4d_populate_tests(&args);
pgd_populate_tests(&args);
spin_unlock(&(args.mm->page_table_lock));
destroy_args(&args);
return 0;
}
late_initcall(debug_vm_pgtable);
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