suse man page for strncpy_from_user

STRNCPY_FROM_USER(9)					    Memory Management in Linux					      STRNCPY_FROM_USER(9)

NAME
       strncpy_from_user - Copy a NUL terminated string from userspace.

SYNOPSIS
       long strncpy_from_user(char * dst, const char __user * src, long count);

ARGUMENTS
       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.

DESCRIPTION
       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.

COPYRIGHT
Kernel Hackers Manual 2.6.					     July 2010						      STRNCPY_FROM_USER(9)