strncpy_from_user9

Copy a nul terminated string from userspace.

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.

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.