1 files changed, 74 insertions, 12 deletions
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index c05d9dcf7891..a9bd6ce1ba02 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -58,11 +58,23 @@
 #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, pgprot_t prot)
+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)));
 
-	pr_debug("Validating PTE basic\n");
 	WARN_ON(!pte_same(pte, pte));
 	WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte))));
 	WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte))));
@@ -70,6 +82,8 @@ static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot)
 	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,
@@ -129,14 +143,27 @@ static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot)
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot)
+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\n");
+	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))));
@@ -144,6 +171,8 @@ static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot)
 	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().
@@ -249,19 +278,35 @@ static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
 }
 
 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
-static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot)
+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\n");
+	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;
@@ -359,7 +404,7 @@ 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(unsigned long pfn, pgprot_t prot) { }
+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,
@@ -372,8 +417,8 @@ 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_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,
@@ -899,6 +944,7 @@ static int __init debug_vm_pgtable(void)
 	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);
@@ -963,9 +1009,25 @@ static int __init debug_vm_pgtable(void)
 	saved_pmdp = pmd_offset(pudp, 0UL);
 	saved_ptep = pmd_pgtable(pmd);
 
-	pte_basic_tests(pte_aligned, prot);
-	pmd_basic_tests(pmd_aligned, prot);
-	pud_basic_tests(pud_aligned, prot);
+	/*
+	 * 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);