__clear_user
Name
__clear_user -- Zero a block of memory in user space, with less checking.
Synopsis
unsigned long __clear_user (void * to, unsigned long n);
Arguments
to Destination address, in user space.
n Number of bytes to zero.
Description
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.