4 files changed, 34 insertions, 14 deletions

diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index acfe755562a6..1e5a40673953 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -196,19 +196,21 @@ enum page_cache_mode {
 #define __PAGE_KERNEL_NOENC     (__PAGE_KERNEL)
 #define __PAGE_KERNEL_NOENC_WP  (__PAGE_KERNEL_WP)
 
-#define PAGE_KERNEL             __pgprot(__PAGE_KERNEL | _PAGE_ENC)
-#define PAGE_KERNEL_NOENC       __pgprot(__PAGE_KERNEL)
-#define PAGE_KERNEL_RO          __pgprot(__PAGE_KERNEL_RO | _PAGE_ENC)
-#define PAGE_KERNEL_EXEC        __pgprot(__PAGE_KERNEL_EXEC | _PAGE_ENC)
-#define PAGE_KERNEL_EXEC_NOENC  __pgprot(__PAGE_KERNEL_EXEC)
-#define PAGE_KERNEL_RX          __pgprot(__PAGE_KERNEL_RX | _PAGE_ENC)
-#define PAGE_KERNEL_NOCACHE     __pgprot(__PAGE_KERNEL_NOCACHE | _PAGE_ENC)
-#define PAGE_KERNEL_LARGE       __pgprot(__PAGE_KERNEL_LARGE | _PAGE_ENC)
-#define PAGE_KERNEL_LARGE_EXEC  __pgprot(__PAGE_KERNEL_LARGE_EXEC | _PAGE_ENC)
-#define PAGE_KERNEL_VVAR        __pgprot(__PAGE_KERNEL_VVAR | _PAGE_ENC)
-
-#define PAGE_KERNEL_IO          __pgprot(__PAGE_KERNEL_IO)
-#define PAGE_KERNEL_IO_NOCACHE  __pgprot(__PAGE_KERNEL_IO_NOCACHE)
+#define default_pgprot(x)       __pgprot((x) & __default_kernel_pte_mask)
+
+#define PAGE_KERNEL             default_pgprot(__PAGE_KERNEL | _PAGE_ENC)
+#define PAGE_KERNEL_NOENC       default_pgprot(__PAGE_KERNEL)
+#define PAGE_KERNEL_RO          default_pgprot(__PAGE_KERNEL_RO | _PAGE_ENC)
+#define PAGE_KERNEL_EXEC        default_pgprot(__PAGE_KERNEL_EXEC | _PAGE_ENC)
+#define PAGE_KERNEL_EXEC_NOENC  default_pgprot(__PAGE_KERNEL_EXEC)
+#define PAGE_KERNEL_RX          default_pgprot(__PAGE_KERNEL_RX | _PAGE_ENC)
+#define PAGE_KERNEL_NOCACHE     default_pgprot(__PAGE_KERNEL_NOCACHE | _PAGE_ENC)
+#define PAGE_KERNEL_LARGE       default_pgprot(__PAGE_KERNEL_LARGE | _PAGE_ENC)
+#define PAGE_KERNEL_LARGE_EXEC  default_pgprot(__PAGE_KERNEL_LARGE_EXEC | _PAGE_ENC)
+#define PAGE_KERNEL_VVAR        default_pgprot(__PAGE_KERNEL_VVAR | _PAGE_ENC)
+
+#define PAGE_KERNEL_IO          default_pgprot(__PAGE_KERNEL_IO)
+#define PAGE_KERNEL_IO_NOCACHE  default_pgprot(__PAGE_KERNEL_IO_NOCACHE)
 
 #endif  /* __ASSEMBLY__ */
 
@@ -483,6 +485,7 @@ static inline pgprot_t pgprot_large_2_4k(pgprot_t pgprot)
 typedef struct page *pgtable_t;
 
 extern pteval_t __supported_pte_mask;
+extern pteval_t __default_kernel_pte_mask;
 extern void set_nx(void);
 extern int nx_enabled;
 
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 82f5252c723a..583a88c8a6ee 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -190,6 +190,12 @@ static void __init probe_page_size_mask(void)
                 enable_global_pages();
         }
 
+        /* By the default is everything supported: */
+        __default_kernel_pte_mask = __supported_pte_mask;
+        /* Except when with PTI where the kernel is mostly non-Global: */
+        if (cpu_feature_enabled(X86_FEATURE_PTI))
+                __default_kernel_pte_mask &= ~_PAGE_GLOBAL;
+
         /* Enable 1 GB linear kernel mappings if available: */
         if (direct_gbpages && boot_cpu_has(X86_FEATURE_GBPAGES)) {
                 printk(KERN_INFO "Using GB pages for direct mapping\n");
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 396e1f0151ac..07cdc2ed4965 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -558,8 +558,14 @@ static void __init pagetable_init(void)
         permanent_kmaps_init(pgd_base);
 }
 
-pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL);
+#define DEFAULT_PTE_MASK ~(_PAGE_NX | _PAGE_GLOBAL)
+/* Bits supported by the hardware: */
+pteval_t __supported_pte_mask __read_mostly = DEFAULT_PTE_MASK;
+/* Bits allowed in normal kernel mappings: */
+pteval_t __default_kernel_pte_mask __read_mostly = DEFAULT_PTE_MASK;
 EXPORT_SYMBOL_GPL(__supported_pte_mask);
+/* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
+EXPORT_SYMBOL(__default_kernel_pte_mask);
 
 /* user-defined highmem size */
 static unsigned int highmem_pages = -1;
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 45241de66785..e6c52dbbf649 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -65,8 +65,13 @@
  * around without checking the pgd every time.
  */
 
+/* Bits supported by the hardware: */
 pteval_t __supported_pte_mask __read_mostly = ~0;
+/* Bits allowed in normal kernel mappings: */
+pteval_t __default_kernel_pte_mask __read_mostly = ~0;
 EXPORT_SYMBOL_GPL(__supported_pte_mask);
+/* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */
+EXPORT_SYMBOL(__default_kernel_pte_mask);
 
 int force_personality32;