1 files changed, 11 insertions, 64 deletions

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 02ace3491c51..763620ec7925 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -256,8 +256,6 @@ extern unsigned long VMALLOC_START;
 #define _PAGE_TYPE_FILE         0x601   /* bit 0x002 is used for offset !! */
 #define _PAGE_TYPE_RO           0x200
 #define _PAGE_TYPE_RW           0x000
-#define _PAGE_TYPE_EX_RO        0x202
-#define _PAGE_TYPE_EX_RW        0x002
 
 /*
  * Only four types for huge pages, using the invalid bit and protection bit
@@ -287,8 +285,6 @@ extern unsigned long VMALLOC_START;
  * _PAGE_TYPE_FILE      11?1   ->   11?1
  * _PAGE_TYPE_RO        0100   ->   1100
  * _PAGE_TYPE_RW        0000   ->   1000
- * _PAGE_TYPE_EX_RO     0110   ->   1110
- * _PAGE_TYPE_EX_RW     0010   ->   1010
  *
  * pte_none is true for bits combinations 1000, 1010, 1100, 1110
  * pte_present is true for bits combinations 0000, 0010, 0100, 0110, 1001
@@ -387,55 +383,33 @@ extern unsigned long VMALLOC_START;
 #define PAGE_NONE       __pgprot(_PAGE_TYPE_NONE)
 #define PAGE_RO         __pgprot(_PAGE_TYPE_RO)
 #define PAGE_RW         __pgprot(_PAGE_TYPE_RW)
-#define PAGE_EX_RO      __pgprot(_PAGE_TYPE_EX_RO)
-#define PAGE_EX_RW      __pgprot(_PAGE_TYPE_EX_RW)
 
 #define PAGE_KERNEL     PAGE_RW
 #define PAGE_COPY       PAGE_RO
 
 /*
- * Dependent on the EXEC_PROTECT option s390 can do execute protection.
- * Write permission always implies read permission. In theory with a
- * primary/secondary page table execute only can be implemented but
- * it would cost an additional bit in the pte to distinguish all the
- * different pte types. To avoid that execute permission currently
- * implies read permission as well.
+ * On s390 the page table entry has an invalid bit and a read-only bit.
+ * Read permission implies execute permission and write permission
+ * implies read permission.
  */
          /*xwr*/
 #define __P000  PAGE_NONE
 #define __P001  PAGE_RO
 #define __P010  PAGE_RO
 #define __P011  PAGE_RO
-#define __P100  PAGE_EX_RO
-#define __P101  PAGE_EX_RO
-#define __P110  PAGE_EX_RO
-#define __P111  PAGE_EX_RO
+#define __P100  PAGE_RO
+#define __P101  PAGE_RO
+#define __P110  PAGE_RO
+#define __P111  PAGE_RO
 
 #define __S000  PAGE_NONE
 #define __S001  PAGE_RO
 #define __S010  PAGE_RW
 #define __S011  PAGE_RW
-#define __S100  PAGE_EX_RO
-#define __S101  PAGE_EX_RO
-#define __S110  PAGE_EX_RW
-#define __S111  PAGE_EX_RW
-
-#ifndef __s390x__
-# define PxD_SHADOW_SHIFT       1
-#else /* __s390x__ */
-# define PxD_SHADOW_SHIFT       2
-#endif /* __s390x__ */
-
-static inline void *get_shadow_table(void *table)
-{
-        unsigned long addr, offset;
-        struct page *page;
-
-        addr = (unsigned long) table;
-        offset = addr & ((PAGE_SIZE << PxD_SHADOW_SHIFT) - 1);
-        page = virt_to_page((void *)(addr ^ offset));
-        return (void *)(addr_t)(page->index ? (page->index | offset) : 0UL);
-}
+#define __S100  PAGE_RO
+#define __S101  PAGE_RO
+#define __S110  PAGE_RW
+#define __S111  PAGE_RW
 
 /*
  * Certain architectures need to do special things when PTEs
@@ -446,14 +420,6 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
                               pte_t *ptep, pte_t entry)
 {
         *ptep = entry;
-        if (mm->context.noexec) {
-                if (!(pte_val(entry) & _PAGE_INVALID) &&
-                    (pte_val(entry) & _PAGE_SWX))
-                        pte_val(entry) |= _PAGE_RO;
-                else
-                        pte_val(entry) = _PAGE_TYPE_EMPTY;
-                ptep[PTRS_PER_PTE] = entry;
-        }
 }
 
 /*
@@ -662,11 +628,7 @@ static inline void pgd_clear_kernel(pgd_t * pgd)
 
 static inline void pgd_clear(pgd_t * pgd)
 {
-        pgd_t *shadow = get_shadow_table(pgd);
-
         pgd_clear_kernel(pgd);
-        if (shadow)
-                pgd_clear_kernel(shadow);
 }
 
 static inline void pud_clear_kernel(pud_t *pud)
@@ -677,13 +639,8 @@ static inline void pud_clear_kernel(pud_t *pud)
 
 static inline void pud_clear(pud_t *pud)
 {
-        pud_t *shadow = get_shadow_table(pud);
-
         pud_clear_kernel(pud);
-        if (shadow)
-                pud_clear_kernel(shadow);
 }
-
 #endif /* __s390x__ */
 
 static inline void pmd_clear_kernel(pmd_t * pmdp)
@@ -693,18 +650,12 @@ static inline void pmd_clear_kernel(pmd_t * pmdp)
 
 static inline void pmd_clear(pmd_t *pmd)
 {
-        pmd_t *shadow = get_shadow_table(pmd);
-
         pmd_clear_kernel(pmd);
-        if (shadow)
-                pmd_clear_kernel(shadow);
 }
 
 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
         pte_val(*ptep) = _PAGE_TYPE_EMPTY;
-        if (mm->context.noexec)
-                pte_val(ptep[PTRS_PER_PTE]) = _PAGE_TYPE_EMPTY;
 }
 
 /*
@@ -903,10 +854,6 @@ static inline void ptep_invalidate(struct mm_struct *mm,
         }
         __ptep_ipte(address, ptep);
         pte_val(*ptep) = _PAGE_TYPE_EMPTY;
-        if (mm->context.noexec) {
-                __ptep_ipte(address, ptep + PTRS_PER_PTE);
-                pte_val(*(ptep + PTRS_PER_PTE)) = _PAGE_TYPE_EMPTY;
-        }
 }
 
 /*