__STRNCPY_FROM_USER(9) Memory Management in Linux __STRNCPY_FROM_USER(9)NAME__strncpy_from_user - Copy a NUL terminated string from userspace, with
less checking.
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. Caller
must check the specified block with access_ok before calling this
function.
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.
COPYRIGHTKernel Hackers Manual 2.6. November 2013 __STRNCPY_FROM_USER(9)