Name
_copy_from_user — 
     Copy a block of data from user space.
 
Synopsis
| unsigned long _copy_from_user ( | void * to, | 
|  | const void __user * from, | 
|  | unsigned n ); | 
 
Arguments
- to
- 
     Destination address, in kernel space.
     
- from
- 
     Source address, in user space.
     
- n
- 
     Number of bytes to copy.
     
Context
   User context only. This function may sleep if pagefaults are
   enabled.
Description
   Copy data from user space to kernel space.
   
   Returns number of bytes that could not be copied.
   On success, this will be zero.
   
   If some data could not be copied, this function will pad the copied
   data to the requested size using zero bytes.