Re: [PATCH V3 2/4] mm/debug_vm_pgtable: Add tests validating advanced arch page table helpers
From: Christophe Leroy
Date: Sat Jun 27 2020 - 03:19:14 EST
Le 15/06/2020 Ã 05:37, Anshuman Khandual a ÃcritÂ:
This adds new tests validating for these following arch advanced page table
helpers. These tests create and test specific mapping types at various page
table levels.
1. pxxp_set_wrprotect()
2. pxxp_get_and_clear()
3. pxxp_set_access_flags()
4. pxxp_get_and_clear_full()
5. pxxp_test_and_clear_young()
6. pxx_leaf()
7. pxx_set_huge()
8. pxx_(clear|mk)_savedwrite()
9. huge_pxxp_xxx()
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: linux-snps-arc@xxxxxxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: linux-s390@xxxxxxxxxxxxxxx
Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx
Cc: x86@xxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Suggested-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
mm/debug_vm_pgtable.c | 306 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 306 insertions(+)
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index ffa163d4c63c..e3f9f8317a98 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -21,6 +21,7 @@
#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>
@@ -28,6 +29,7 @@
#include <linux/start_kernel.h>
#include <linux/sched/mm.h>
#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
#define VMFLAGS (VM_READ|VM_WRITE|VM_EXEC)
@@ -55,6 +57,54 @@ static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot)
WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(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);
+
+ pte = pfn_pte(pfn, prot);
+ set_pte_at(mm, vaddr, ptep, pte);
+ ptep_set_wrprotect(mm, vaddr, ptep);
+ pte = READ_ONCE(*ptep);
same
+ WARN_ON(pte_write(pte));
+
+ pte = pfn_pte(pfn, prot);
+ set_pte_at(mm, vaddr, ptep, pte);
+ ptep_get_and_clear(mm, vaddr, ptep);
+ pte = READ_ONCE(*ptep);
same
+ 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 = READ_ONCE(*ptep);
same
+ WARN_ON(!(pte_write(pte) && pte_dirty(pte)));
+
+ pte = pfn_pte(pfn, prot);
+ set_pte_at(mm, vaddr, ptep, pte);
+ ptep_get_and_clear_full(mm, vaddr, ptep, 1);
+ pte = READ_ONCE(*ptep);
same
+ WARN_ON(!pte_none(pte));
+
+ pte = pte_mkyoung(pte);
+ set_pte_at(mm, vaddr, ptep, pte);
+ ptep_test_and_clear_young(vma, vaddr, ptep);
+ pte = READ_ONCE(*ptep);
same
+ WARN_ON(pte_young(pte));
+}
+
+static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot)
+{
+ pte_t pte = pfn_pte(pfn, prot);
+
+ 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, pgprot_t prot)
{
@@ -77,6 +127,89 @@ static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot)
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)
+{
+ pmd_t pmd = pfn_pmd(pfn, prot);
+
+ if (!has_transparent_hugepage())
+ return;
+
+ /* Align the address wrt HPAGE_PMD_SIZE */
+ vaddr = (vaddr & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE;
+
+ 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));
+
+ pmd = pfn_pmd(pfn, prot);
+ set_pmd_at(mm, vaddr, pmdp, 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)));
+
+ pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
+ set_pmd_at(mm, vaddr, pmdp, pmd);
+ pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1);
+ pmd = READ_ONCE(*pmdp);
+ WARN_ON(!pmd_none(pmd));
+
+ 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));
+}
+
+static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot)
+{
+ pmd_t pmd = pfn_pmd(pfn, prot);
+
+ /*
+ * PMD based THP is a leaf entry.
+ */
+ pmd = pmd_mkhuge(pmd);
+ WARN_ON(!pmd_leaf(pmd));
+}
+
+static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
+{
+ pmd_t pmd;
+
+ if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
+ return;
+ /*
+ * 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));
+}
+
+static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
+{
+ pmd_t pmd = pfn_pmd(pfn, prot);
+
+ WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd))));
+ WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd))));
+}
+
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot)
{
@@ -100,12 +233,115 @@ static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot)
*/
WARN_ON(!pud_bad(pud_mkhuge(pud)));
}
+
+static void 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;
+
+ /* 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
+ pud = pfn_pud(pfn, prot);
+ set_pud_at(mm, vaddr, pudp, pud);
+ pudp_huge_get_and_clear(mm, vaddr, pudp);
+ pud = READ_ONCE(*pudp);
+ WARN_ON(!pud_none(pud));
+
+ pud = pfn_pud(pfn, prot);
+ set_pud_at(mm, vaddr, pudp, pud);
+ 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_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)));
+
+ 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));
+}
+
+static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
+{
+ pud_t pud = pfn_pud(pfn, prot);
+
+ /*
+ * PUD based THP is a leaf entry.
+ */
+ pud = pud_mkhuge(pud);
+ WARN_ON(!pud_leaf(pud));
+}
+
+static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
+{
+ pud_t pud;
+
+ if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
+ return;
+ /*
+ * 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_TRANSPARENT_HUGEPAGE_PUD */
static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
+static void 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, pgprot_t prot) { }
static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
+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)
+{
+}
+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)
@@ -495,8 +731,56 @@ static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot)
WARN_ON(!pte_huge(pte_mkhuge(pte)));
#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
}
+
+static void __init hugetlb_advanced_tests(struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ pte_t *ptep, unsigned long pfn,
+ unsigned long vaddr, pgprot_t prot)
+{
+ struct page *page = pfn_to_page(pfn);
+ pte_t pte = READ_ONCE(*ptep);
Remplace with ptep_get() to avoid build failure on powerpc 8xx.
+ unsigned long paddr = (__pfn_to_phys(pfn) | RANDOM_ORVALUE) & PMD_MASK;
+
+ pte = pte_mkhuge(mk_pte(pfn_to_page(PHYS_PFN(paddr)), prot));
+ set_huge_pte_at(mm, vaddr, ptep, pte);
+ barrier();
+ WARN_ON(!pte_same(pte, huge_ptep_get(ptep)));
+ huge_pte_clear(mm, vaddr, ptep, PMD_SIZE);
+ pte = huge_ptep_get(ptep);
+ WARN_ON(!huge_pte_none(pte));
+
+ pte = mk_huge_pte(page, prot);
+ set_huge_pte_at(mm, vaddr, ptep, pte);
+ barrier();
+ huge_ptep_set_wrprotect(mm, vaddr, ptep);
+ pte = huge_ptep_get(ptep);
+ WARN_ON(huge_pte_write(pte));
+
+ pte = mk_huge_pte(page, prot);
+ set_huge_pte_at(mm, vaddr, ptep, pte);
+ barrier();
+ huge_ptep_get_and_clear(mm, vaddr, ptep);
+ pte = huge_ptep_get(ptep);
+ WARN_ON(!huge_pte_none(pte));
+
+ pte = mk_huge_pte(page, prot);
+ pte = huge_pte_wrprotect(pte);
+ set_huge_pte_at(mm, vaddr, ptep, pte);
+ barrier();
+ pte = huge_pte_mkwrite(pte);
+ pte = huge_pte_mkdirty(pte);
+ huge_ptep_set_access_flags(vma, vaddr, ptep, pte, 1);
+ pte = huge_ptep_get(ptep);
+ WARN_ON(!(huge_pte_write(pte) && huge_pte_dirty(pte)));
+}
#else /* !CONFIG_HUGETLB_PAGE */
static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init hugetlb_advanced_tests(struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ pte_t *ptep, unsigned long pfn,
+ unsigned long vaddr, pgprot_t prot)
+{
+}
#endif /* CONFIG_HUGETLB_PAGE */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -568,6 +852,7 @@ static unsigned long __init get_random_vaddr(void)
static int __init debug_vm_pgtable(void)
{
+ struct vm_area_struct *vma;
struct mm_struct *mm;
pgd_t *pgdp;
p4d_t *p4dp, *saved_p4dp;
@@ -596,6 +881,12 @@ static int __init debug_vm_pgtable(void)
*/
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
@@ -644,6 +935,20 @@ static int __init debug_vm_pgtable(void)
p4d_clear_tests(mm, p4dp);
pgd_clear_tests(mm, pgdp);
+ pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
+ pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot);
+ pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot);
+ hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
+
+ pmd_leaf_tests(pmd_aligned, prot);
+ pud_leaf_tests(pud_aligned, prot);
+
+ pmd_huge_tests(pmdp, pmd_aligned, prot);
+ pud_huge_tests(pudp, pud_aligned, prot);
+
+ pte_savedwrite_tests(pte_aligned, prot);
+ pmd_savedwrite_tests(pmd_aligned, prot);
+
pte_unmap_unlock(ptep, ptl);
pmd_populate_tests(mm, pmdp, saved_ptep);
@@ -678,6 +983,7 @@ static int __init debug_vm_pgtable(void)
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);
Christophe