#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
/*
* PTE type bits are rather complicated. handle_pte_fault uses pte_present,
* _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, 1100
+ * pte_none is true for bits combinations 1000, 1010, 1100, 1110
* pte_present is true for bits combinations 0000, 0010, 0100, 0110, 1001
* pte_file is true for bits combinations 1101, 1111
- * swap pte is 1011 and 0001, 0011, 0101, 0111, 1010 and 1110 are invalid.
+ * swap pte is 1011 and 0001, 0011, 0101, 0111 are invalid.
*/
#ifndef __s390x__
#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
/*
- * The S390 can't do page protection for execute, and considers that the
- * same are read. Also, write permissions imply read permissions. This is
- * the closest we can get..
+ * 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.
*/
/*xwr*/
#define __P000 PAGE_NONE
#define __P001 PAGE_RO
#define __P010 PAGE_RO
#define __P011 PAGE_RO
-#define __P100 PAGE_RO
-#define __P101 PAGE_RO
-#define __P110 PAGE_RO
-#define __P111 PAGE_RO
+#define __P100 PAGE_EX_RO
+#define __P101 PAGE_EX_RO
+#define __P110 PAGE_EX_RO
+#define __P111 PAGE_EX_RO
#define __S000 PAGE_NONE
#define __S001 PAGE_RO
#define __S010 PAGE_RW
#define __S011 PAGE_RW
-#define __S100 PAGE_RO
-#define __S101 PAGE_RO
-#define __S110 PAGE_RW
-#define __S111 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 PMD_SHADOW_SHIFT 1
+# define PGD_SHADOW_SHIFT 1
+#else /* __s390x__ */
+# define PMD_SHADOW_SHIFT 2
+# define PGD_SHADOW_SHIFT 2
+#endif /* __s390x__ */
+
+static inline struct page *get_shadow_page(struct page *page)
+{
+ if (s390_noexec && !list_empty(&page->lru))
+ return virt_to_page(page->lru.next);
+ return NULL;
+}
+
+static inline pte_t *get_shadow_pte(pte_t *ptep)
+{
+ unsigned long pteptr = (unsigned long) (ptep);
+
+ if (s390_noexec) {
+ unsigned long offset = pteptr & (PAGE_SIZE - 1);
+ void *addr = (void *) (pteptr ^ offset);
+ struct page *page = virt_to_page(addr);
+ if (!list_empty(&page->lru))
+ return (pte_t *) ((unsigned long) page->lru.next |
+ offset);
+ }
+ return NULL;
+}
+
+static inline pmd_t *get_shadow_pmd(pmd_t *pmdp)
+{
+ unsigned long pmdptr = (unsigned long) (pmdp);
+
+ if (s390_noexec) {
+ unsigned long offset = pmdptr &
+ ((PAGE_SIZE << PMD_SHADOW_SHIFT) - 1);
+ void *addr = (void *) (pmdptr ^ offset);
+ struct page *page = virt_to_page(addr);
+ if (!list_empty(&page->lru))
+ return (pmd_t *) ((unsigned long) page->lru.next |
+ offset);
+ }
+ return NULL;
+}
+
+static inline pgd_t *get_shadow_pgd(pgd_t *pgdp)
+{
+ unsigned long pgdptr = (unsigned long) (pgdp);
+
+ if (s390_noexec) {
+ unsigned long offset = pgdptr &
+ ((PAGE_SIZE << PGD_SHADOW_SHIFT) - 1);
+ void *addr = (void *) (pgdptr ^ offset);
+ struct page *page = virt_to_page(addr);
+ if (!list_empty(&page->lru))
+ return (pgd_t *) ((unsigned long) page->lru.next |
+ offset);
+ }
+ return NULL;
+}
/*
* Certain architectures need to do special things when PTEs
*/
static inline void set_pte(pte_t *pteptr, pte_t pteval)
{
+ pte_t *shadow_pte = get_shadow_pte(pteptr);
+
*pteptr = pteval;
+ if (shadow_pte) {
+ if (!(pte_val(pteval) & _PAGE_INVALID) &&
+ (pte_val(pteval) & _PAGE_SWX))
+ pte_val(*shadow_pte) = pte_val(pteval) | _PAGE_RO;
+ else
+ pte_val(*shadow_pte) = _PAGE_TYPE_EMPTY;
+ }
}
#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
static inline void pgd_clear(pgd_t * pgdp) { }
-static inline void pmd_clear(pmd_t * pmdp)
+static inline void pmd_clear_kernel(pmd_t * pmdp)
{
pmd_val(pmdp[0]) = _PAGE_TABLE_INV;
pmd_val(pmdp[1]) = _PAGE_TABLE_INV;
pmd_val(pmdp[3]) = _PAGE_TABLE_INV;
}
+static inline void pmd_clear(pmd_t * pmdp)
+{
+ pmd_t *shadow_pmd = get_shadow_pmd(pmdp);
+
+ pmd_clear_kernel(pmdp);
+ if (shadow_pmd)
+ pmd_clear_kernel(shadow_pmd);
+}
+
#else /* __s390x__ */
-static inline void pgd_clear(pgd_t * pgdp)
+static inline void pgd_clear_kernel(pgd_t * pgdp)
{
pgd_val(*pgdp) = _PGD_ENTRY_INV | _PGD_ENTRY;
}
-static inline void pmd_clear(pmd_t * pmdp)
+static inline void pgd_clear(pgd_t * pgdp)
+{
+ pgd_t *shadow_pgd = get_shadow_pgd(pgdp);
+
+ pgd_clear_kernel(pgdp);
+ if (shadow_pgd)
+ pgd_clear_kernel(shadow_pgd);
+}
+
+static inline void pmd_clear_kernel(pmd_t * pmdp)
{
pmd_val(*pmdp) = _PMD_ENTRY_INV | _PMD_ENTRY;
pmd_val1(*pmdp) = _PMD_ENTRY_INV | _PMD_ENTRY;
}
+static inline void pmd_clear(pmd_t * pmdp)
+{
+ pmd_t *shadow_pmd = get_shadow_pmd(pmdp);
+
+ pmd_clear_kernel(pmdp);
+ if (shadow_pmd)
+ pmd_clear_kernel(shadow_pmd);
+}
+
#endif /* __s390x__ */
static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
+ pte_t *shadow_pte = get_shadow_pte(ptep);
+
pte_val(*ptep) = _PAGE_TYPE_EMPTY;
+ if (shadow_pte)
+ pte_val(*shadow_pte) = _PAGE_TYPE_EMPTY;
}
/*
unsigned long address, pte_t *ptep)
{
pte_t pte = *ptep;
+ pte_t *shadow_pte = get_shadow_pte(ptep);
__ptep_ipte(address, ptep);
+ if (shadow_pte)
+ __ptep_ipte(address, shadow_pte);
return pte;
}
projects / linux-2.6-omap-h63xx.git / blobdiff