[PATCH -next 1/4] mm: page_table_check: move pxx_user_accessible_page into x86

From: Tong Tiangen
Date: Thu Mar 17 2022 - 09:53:36 EST


From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>

The pxx_user_accessible_page() check the PTE bit, it's
architecture-specific code, move them into x86's pgtable.h,
also add default PMD/PUD_PAGE_SIZE definition, it's prepare
for support page table check feature on new architecture.

Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
arch/x86/include/asm/pgtable.h | 19 +++++++++++++++++++
mm/page_table_check.c | 25 ++++++++-----------------
2 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 62ab07e24aef..8cd6514e3052 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1430,6 +1430,25 @@ static inline bool arch_faults_on_old_pte(void)
return false;
}

+#ifdef CONFIG_PAGE_TABLE_CHECK
+static inline bool pte_user_accessible_page(pte_t pte)
+{
+ return (pte_val(pte) & _PAGE_PRESENT) && (pte_val(pte) & _PAGE_USER);
+}
+
+static inline bool pmd_user_accessible_page(pmd_t pmd)
+{
+ return pmd_leaf(pmd) && (pmd_val(pmd) & _PAGE_PRESENT) &&
+ (pmd_val(pmd) & _PAGE_USER);
+}
+
+static inline bool pud_user_accessible_page(pud_t pud)
+{
+ return pud_leaf(pud) && (pud_val(pud) & _PAGE_PRESENT) &&
+ (pud_val(pud) & _PAGE_USER);
+}
+#endif
+
#endif /* __ASSEMBLY__ */

#endif /* _ASM_X86_PGTABLE_H */
diff --git a/mm/page_table_check.c b/mm/page_table_check.c
index 2458281bff89..145f059d1c4d 100644
--- a/mm/page_table_check.c
+++ b/mm/page_table_check.c
@@ -10,6 +10,14 @@
#undef pr_fmt
#define pr_fmt(fmt) "page_table_check: " fmt

+#ifndef PMD_PAGE_SIZE
+#define PMD_PAGE_SIZE PMD_SIZE
+#endif
+
+#ifndef PUD_PAGE_SIZE
+#define PUD_PAGE_SIZE PUD_SIZE
+#endif
+
struct page_table_check {
atomic_t anon_map_count;
atomic_t file_map_count;
@@ -52,23 +60,6 @@ static struct page_table_check *get_page_table_check(struct page_ext *page_ext)
return (void *)(page_ext) + page_table_check_ops.offset;
}

-static inline bool pte_user_accessible_page(pte_t pte)
-{
- return (pte_val(pte) & _PAGE_PRESENT) && (pte_val(pte) & _PAGE_USER);
-}
-
-static inline bool pmd_user_accessible_page(pmd_t pmd)
-{
- return pmd_leaf(pmd) && (pmd_val(pmd) & _PAGE_PRESENT) &&
- (pmd_val(pmd) & _PAGE_USER);
-}
-
-static inline bool pud_user_accessible_page(pud_t pud)
-{
- return pud_leaf(pud) && (pud_val(pud) & _PAGE_PRESENT) &&
- (pud_val(pud) & _PAGE_USER);
-}
-
/*
* An enty is removed from the page table, decrement the counters for that page
* verify that it is of correct type and counters do not become negative.
--
2.18.0.huawei.25