1 files changed, 55 insertions, 28 deletions

diff --git a/arch/s390/lib/uaccess_pt.c b/arch/s390/lib/uaccess_pt.c
index dff631d34b45..466fb3383960 100644
--- a/arch/s390/lib/uaccess_pt.c
+++ b/arch/s390/lib/uaccess_pt.c
@@ -77,42 +77,69 @@ static size_t copy_in_kernel(size_t count, void __user *to,
  * >= -4095 (IS_ERR_VALUE(x) returns true), a fault has occured and the address
  * contains the (negative) exception code.
  */
-static __always_inline unsigned long follow_table(struct mm_struct *mm,
-                                                  unsigned long addr, int write)
+#ifdef CONFIG_64BIT
+static unsigned long follow_table(struct mm_struct *mm,
+                                  unsigned long address, int write)
 {
-        pgd_t *pgd;
-        pud_t *pud;
-        pmd_t *pmd;
-        pte_t *ptep;
+        unsigned long *table = (unsigned long *)__pa(mm->pgd);
+
+        switch (mm->context.asce_bits & _ASCE_TYPE_MASK) {
+        case _ASCE_TYPE_REGION1:
+                table = table + ((address >> 53) & 0x7ff);
+                if (unlikely(*table & _REGION_ENTRY_INV))
+                        return -0x39UL;
+                table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+        case _ASCE_TYPE_REGION2:
+                table = table + ((address >> 42) & 0x7ff);
+                if (unlikely(*table & _REGION_ENTRY_INV))
+                        return -0x3aUL;
+                table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+        case _ASCE_TYPE_REGION3:
+                table = table + ((address >> 31) & 0x7ff);
+                if (unlikely(*table & _REGION_ENTRY_INV))
+                        return -0x3bUL;
+                table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+        case _ASCE_TYPE_SEGMENT:
+                table = table + ((address >> 20) & 0x7ff);
+                if (unlikely(*table & _SEGMENT_ENTRY_INV))
+                        return -0x10UL;
+                if (unlikely(*table & _SEGMENT_ENTRY_LARGE)) {
+                        if (write && (*table & _SEGMENT_ENTRY_RO))
+                                return -0x04UL;
+                        return (*table & _SEGMENT_ENTRY_ORIGIN_LARGE) +
+                                (address & ~_SEGMENT_ENTRY_ORIGIN_LARGE);
+                }
+                table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN);
+        }
+        table = table + ((address >> 12) & 0xff);
+        if (unlikely(*table & _PAGE_INVALID))
+                return -0x11UL;
+        if (write && (*table & _PAGE_RO))
+                return -0x04UL;
+        return (*table & PAGE_MASK) + (address & ~PAGE_MASK);
+}
 
-        pgd = pgd_offset(mm, addr);
-        if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
-                return -0x3aUL;
+#else /* CONFIG_64BIT */
 
-        pud = pud_offset(pgd, addr);
-        if (pud_none(*pud) || unlikely(pud_bad(*pud)))
-                return -0x3bUL;
+static unsigned long follow_table(struct mm_struct *mm,
+                                  unsigned long address, int write)
+{
+        unsigned long *table = (unsigned long *)__pa(mm->pgd);
 
-        pmd = pmd_offset(pud, addr);
-        if (pmd_none(*pmd))
+        table = table + ((address >> 20) & 0x7ff);
+        if (unlikely(*table & _SEGMENT_ENTRY_INV))
                 return -0x10UL;
-        if (pmd_large(*pmd)) {
-                if (write && (pmd_val(*pmd) & _SEGMENT_ENTRY_RO))
-                        return -0x04UL;
-                return (pmd_val(*pmd) & HPAGE_MASK) + (addr & ~HPAGE_MASK);
-        }
-        if (unlikely(pmd_bad(*pmd)))
-                return -0x10UL;
-
-        ptep = pte_offset_map(pmd, addr);
-        if (!pte_present(*ptep))
+        table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN);
+        table = table + ((address >> 12) & 0xff);
+        if (unlikely(*table & _PAGE_INVALID))
                 return -0x11UL;
-        if (write && (!pte_write(*ptep) || !pte_dirty(*ptep)))
+        if (write && (*table & _PAGE_RO))
                 return -0x04UL;
-
-        return (pte_val(*ptep) & PAGE_MASK) + (addr & ~PAGE_MASK);
+        return (*table & PAGE_MASK) + (address & ~PAGE_MASK);
 }
 
+#endif /* CONFIG_64BIT */
+
 static __always_inline size_t __user_copy_pt(unsigned long uaddr, void *kptr,
                                              size_t n, int write_user)
 {
@@ -197,7 +224,7 @@ size_t copy_to_user_pt(size_t n, void __user *to, const void *from)
 
 static size_t clear_user_pt(size_t n, void __user *to)
 {
-        void *zpage = &empty_zero_page;
+        void *zpage = (void *) empty_zero_page;
         long done, size, ret;
 
         done = 0;