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-rw-r--r--arch/x86/include/asm/pgtable.h18
-rw-r--r--arch/x86/include/asm/pgtable_32.h9
-rw-r--r--arch/x86/include/asm/pgtable_64.h1
3 files changed, 17 insertions, 11 deletions
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 286a71810f9e..0564edd24ffb 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -292,7 +292,23 @@ static inline pte_t pte_clear_flags(pte_t pte, pteval_t clear)
#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
static inline int pte_uffd_wp(pte_t pte)
{
- return pte_flags(pte) & _PAGE_UFFD_WP;
+ bool wp = pte_flags(pte) & _PAGE_UFFD_WP;
+
+#ifdef CONFIG_DEBUG_VM
+ /*
+ * Having write bit for wr-protect-marked present ptes is fatal,
+ * because it means the uffd-wp bit will be ignored and write will
+ * just go through.
+ *
+ * Use any chance of pgtable walking to verify this (e.g., when
+ * page swapped out or being migrated for all purposes). It means
+ * something is already wrong. Tell the admin even before the
+ * process crashes. We also nail it with wrong pgtable setup.
+ */
+ WARN_ON_ONCE(wp && pte_write(pte));
+#endif
+
+ return wp;
}
static inline pte_t pte_mkuffd_wp(pte_t pte)
diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h
index 7c9c968a42ef..7d4ad8907297 100644
--- a/arch/x86/include/asm/pgtable_32.h
+++ b/arch/x86/include/asm/pgtable_32.h
@@ -48,15 +48,6 @@ do { \
#endif /* !__ASSEMBLY__ */
/*
- * kern_addr_valid() is (1) for FLATMEM and (0) for SPARSEMEM
- */
-#ifdef CONFIG_FLATMEM
-#define kern_addr_valid(addr) (1)
-#else
-#define kern_addr_valid(kaddr) (0)
-#endif
-
-/*
* This is used to calculate the .brk reservation for initial pagetables.
* Enough space is reserved to allocate pagetables sufficient to cover all
* of LOWMEM_PAGES, which is an upper bound on the size of the direct map of
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index e479491da8d5..7929327abe00 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -240,7 +240,6 @@ static inline void native_pgd_clear(pgd_t *pgd)
#define __swp_entry_to_pte(x) ((pte_t) { .pte = (x).val })
#define __swp_entry_to_pmd(x) ((pmd_t) { .pmd = (x).val })
-extern int kern_addr_valid(unsigned long addr);
extern void cleanup_highmap(void);
#define HAVE_ARCH_UNMAPPED_AREA