vserver 1.9.3

[linux-2.6.git] / arch / um / include / um_uaccess.h

diff --git a/arch/um/include/um_uaccess.h b/arch/um/include/um_uaccess.h
index 41afa3a..c9b3574 100644 (file)
--- a/arch/um/include/um_uaccess.h
+++ b/arch/um/include/um_uaccess.h
@@ -38,22 +38,73 @@ static inline int copy_to_user(void *to, const void *from, int n)
                                from, n));
 }
 
+/*
+ * strncpy_from_user: - Copy a NUL terminated string from userspace.
+ * @dst:   Destination address, in kernel space.  This buffer must be at
+ *         least @count bytes long.
+ * @src:   Source address, in user space.
+ * @count: Maximum number of bytes to copy, including the trailing NUL.
+ *
+ * Copies a NUL-terminated string from userspace to kernel space.
+ *
+ * On success, returns the length of the string (not including the trailing
+ * NUL).
+ *
+ * If access to userspace fails, returns -EFAULT (some data may have been
+ * copied).
+ *
+ * If @count is smaller than the length of the string, copies @count bytes
+ * and returns @count.
+ */
+
 static inline int strncpy_from_user(char *dst, const char *src, int count)
 {
        return(CHOOSE_MODE_PROC(strncpy_from_user_tt, strncpy_from_user_skas,
                                dst, src, count));
 }
 
+/*
+ * __clear_user: - Zero a block of memory in user space, with less checking.
+ * @to:   Destination address, in user space.
+ * @n:    Number of bytes to zero.
+ *
+ * Zero a block of memory in user space.  Caller must check
+ * the specified block with access_ok() before calling this function.
+ *
+ * Returns number of bytes that could not be cleared.
+ * On success, this will be zero.
+ */
 static inline int __clear_user(void *mem, int len)
 {
        return(CHOOSE_MODE_PROC(__clear_user_tt, __clear_user_skas, mem, len));
 }
 
+/*
+ * clear_user: - Zero a block of memory in user space.
+ * @to:   Destination address, in user space.
+ * @n:    Number of bytes to zero.
+ *
+ * Zero a block of memory in user space.
+ *
+ * Returns number of bytes that could not be cleared.
+ * On success, this will be zero.
+ */
 static inline int clear_user(void *mem, int len)
 {
        return(CHOOSE_MODE_PROC(clear_user_tt, clear_user_skas, mem, len));
 }
 
+/*
+ * strlen_user: - Get the size of a string in user space.
+ * @str: The string to measure.
+ * @n:   The maximum valid length
+ *
+ * Get the size of a NUL-terminated string in user space.
+ *
+ * Returns the size of the string INCLUDING the terminating NUL.
+ * On exception, returns 0.
+ * If the string is too long, returns a value greater than @n.
+ */
 static inline int strnlen_user(const void *str, int len)
 {
        return(CHOOSE_MODE_PROC(strnlen_user_tt, strnlen_user_skas, str, len));