microblaze: uaccess: Fix get_user macro for noMMU
Michal Simek [Mon, 8 Mar 2010 09:52:24 +0000 (10:52 +0100)]
Use unified version.

Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/include/asm/uaccess.h

index 1af9202..b079ac3 100644 (file)
@@ -146,31 +146,75 @@ static inline unsigned long __must_check clear_user(void __user *to,
 
 #ifndef CONFIG_MMU
 
-/* Undefined function to trigger linker error */
-extern int bad_user_access_length(void);
+extern long __user_bad(void);
+
+#define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err)     \
+({                                                             \
+       __asm__ __volatile__ (                                  \
+                       "1:"    insn    " %1, %2, r0;"          \
+                       "       addk    %0, r0, r0;"            \
+                       "2:                     "               \
+                       __FIXUP_SECTION                         \
+                       "3:     brid    2b;"                    \
+                       "       addik   %0, r0, %3;"            \
+                       ".previous;"                            \
+                       __EX_TABLE_SECTION                      \
+                       ".word  1b,3b;"                         \
+                       ".previous;"                            \
+               : "=&r"(__gu_err), "=r"(__gu_val)               \
+               : "r"(__gu_ptr), "i"(-EFAULT)                   \
+       );                                                      \
+})
+
+/**
+ * get_user: - Get a simple variable from user space.
+ * @x:   Variable to store result.
+ * @ptr: Source address, in user space.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * This macro copies a single simple variable from user space to kernel
+ * space.  It supports simple types like char and int, but not larger
+ * data types like structures or arrays.
+ *
+ * @ptr must have pointer-to-simple-variable type, and the result of
+ * dereferencing @ptr must be assignable to @x without a cast.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ * On error, the variable @x is set to zero.
+ */
+
+#define __get_user(x, ptr)                                             \
+({                                                                     \
+       unsigned long __gu_val;                                         \
+       /*unsigned long __gu_ptr = (unsigned long)(ptr);*/              \
+       long __gu_err;                                                  \
+       switch (sizeof(*(ptr))) {                                       \
+       case 1:                                                         \
+               __get_user_asm("lbu", (ptr), __gu_val, __gu_err);       \
+               break;                                                  \
+       case 2:                                                         \
+               __get_user_asm("lhu", (ptr), __gu_val, __gu_err);       \
+               break;                                                  \
+       case 4:                                                         \
+               __get_user_asm("lw", (ptr), __gu_val, __gu_err);        \
+               break;                                                  \
+       default:                                                        \
+               /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
+       }                                                               \
+       x = (__typeof__(*(ptr))) __gu_val;                              \
+       __gu_err;                                                       \
+})
+
 
-/* FIXME this is function for optimalization -> memcpy */
-#define __get_user(var, ptr)                           \
-({                                                     \
-       int __gu_err = 0;                               \
-       switch (sizeof(*(ptr))) {                       \
-       case 1:                                         \
-       case 2:                                         \
-       case 4:                                         \
-               (var) = *(ptr);                         \
-               break;                                  \
-       case 8:                                         \
-               memcpy((void *) &(var), (ptr), 8);      \
-               break;                                  \
-       default:                                        \
-               (var) = 0;                              \
-               __gu_err = __get_user_bad();            \
-               break;                                  \
-       }                                               \
-       __gu_err;                                       \
+#define get_user(x, ptr)                                               \
+({                                                                     \
+       access_ok(VERIFY_READ, (ptr), sizeof(*(ptr)))                   \
+               ? __get_user((x), (ptr)) : -EFAULT;                     \
 })
 
-#define __get_user_bad()       (bad_user_access_length(), (-EFAULT))
+/* Undefined function to trigger linker error */
+extern int bad_user_access_length(void);
 
 /* FIXME is not there defined __pu_val */
 #define __put_user(var, ptr)                                   \
@@ -197,7 +241,6 @@ extern int bad_user_access_length(void);
 #define __put_user_bad()       (bad_user_access_length(), (-EFAULT))
 
 #define put_user(x, ptr)       __put_user((x), (ptr))
-#define get_user(x, ptr)       __get_user((x), (ptr))
 
 #define copy_to_user(to, from, n)      (memcpy((to), (from), (n)), 0)
 #define copy_from_user(to, from, n)    (memcpy((to), (from), (n)), 0)