microblaze: uaccess: sync put/get/clear_user macros

Add macro description and resort.

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

1 files changed, 69 insertions, 37 deletions

diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h
index 1e8fa4b76115..6bb9b8fb6655 100644
--- a/arch/microblaze/include/asm/uaccess.h
+++ b/arch/microblaze/include/asm/uaccess.h
@@ -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))