microblaze: uaccess: sync put/get/clear_user macros
Michal Simek [Mon, 22 Mar 2010 14:46:56 +0000 (15:46 +0100)]
Add macro description and resort.

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

arch/microblaze/include/asm/uaccess.h

index 1e8fa4b..6bb9b8f 100644 (file)
@@ -191,11 +191,38 @@ extern long strnlen_user(const char *src, long count);
 
 #else /* CONFIG_MMU */
 
-/*
- * All the __XXX versions macros/functions below do not perform
- * access checking. It is assumed that the necessary checks have been
- * already performed before the finction (macro) is called.
- */
+/* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */
+static inline unsigned long __must_check __clear_user(void __user *to,
+                                                       unsigned long n)
+{
+       /* normal memset with two words to __ex_table */
+       __asm__ __volatile__ (                          \
+                       "1:     sb      r0, %2, r0;"    \
+                       "       addik   %0, %0, -1;"    \
+                       "       bneid   %0, 1b;"        \
+                       "       addik   %2, %2, 1;"     \
+                       "2:                     "       \
+                       __EX_TABLE_SECTION              \
+                       ".word  1b,2b;"                 \
+                       ".previous;"                    \
+               : "=r"(n)                               \
+               : "0"(n), "r"(to)
+       );
+       return n;
+}
+
+static inline unsigned long __must_check clear_user(void __user *to,
+                                                       unsigned long n)
+{
+       might_sleep();
+       if (unlikely(!access_ok(VERIFY_WRITE, to, n)))
+               return n;
+       return __clear_user(to, n);
+}
+
+/* put_user and get_user macros */
+
+extern long __user_bad(void);
 
 #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err)     \
 ({                                                             \
@@ -231,18 +258,53 @@ extern long strnlen_user(const char *src, long count);
                __get_user_asm("lw", (ptr), __gu_val, __gu_err);        \
                break;                                                  \
        default:                                                        \
-               __gu_val = 0; __gu_err = -EINVAL;                       \
+               /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
        }                                                               \
        x = (__typeof__(*(ptr))) __gu_val;                              \
        __gu_err;                                                       \
 })
 
+/**
+ * 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)                                               \
 ({                                                                     \
        access_ok(VERIFY_READ, (ptr), sizeof(*(ptr)))                   \
                ? __get_user((x), (ptr)) : -EFAULT;                     \
 })
 
+/**
+ * put_user: - Write a simple value into user space.
+ * @x:   Value to copy to user space.
+ * @ptr: Destination address, in user space.
+ *
+ * Context: User context only.  This function may sleep.
+ *
+ * This macro copies a single simple value from kernel space to user
+ * 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 @x must be assignable
+ * to the result of dereferencing @ptr.
+ *
+ * Returns zero on success, or -EFAULT on error.
+ */
+
 #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err)     \
 ({                                                             \
        __asm__ __volatile__ (                                  \
@@ -299,7 +361,7 @@ extern long strnlen_user(const char *src, long count);
                __put_user_asm_8((ptr), __gu_val, __gu_err);            \
                break;                                                  \
        default:                                                        \
-               __gu_err = -EINVAL;                                     \
+               /*__gu_err = -EINVAL;*/ __gu_err = __user_bad();        \
        }                                                               \
        __gu_err;                                                       \
 })
@@ -310,36 +372,6 @@ extern long strnlen_user(const char *src, long count);
                ? __put_user((x), (ptr)) : -EFAULT;                     \
 })
 
-/* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */
-static inline unsigned long __must_check __clear_user(void __user *to,
-                                                       unsigned long n)
-{
-       /* normal memset with two words to __ex_table */
-       __asm__ __volatile__ (                          \
-                       "1:     sb      r0, %2, r0;"    \
-                       "       addik   %0, %0, -1;"    \
-                       "       bneid   %0, 1b;"        \
-                       "       addik   %2, %2, 1;"     \
-                       "2:                     "       \
-                       __EX_TABLE_SECTION              \
-                       ".word  1b,2b;"                 \
-                       ".previous;"                    \
-               : "=r"(n)                               \
-               : "0"(n), "r"(to)
-       );
-       return n;
-}
-
-static inline unsigned long __must_check clear_user(void __user *to,
-                                                       unsigned long n)
-{
-       might_sleep();
-       if (unlikely(!access_ok(VERIFY_WRITE, to, n)))
-               return n;
-
-       return __clear_user(to, n);
-}
-
 #define __copy_from_user(to, from, n)  copy_from_user((to), (from), (n))
 #define __copy_from_user_inatomic(to, from, n) \
                copy_from_user((to), (from), (n))