Provided by: linux-doc-2.6.15_2.6.15-23.39_all
access_ok - Checks if a user space pointer is valid
access_ok (type, addr, size);
type Type of access: VERIFY_READ or VERIFY_WRITE. Note that
VERIFY_WRITE is a superset of VERIFY_READ - if it is safe to
write to a block, it is always safe to read from it.
addr User space pointer to start of block to check
size Size of block to check
User context only. This function may sleep.
Checks if a pointer to a block of memory in user space is valid.
Returns true (nonzero) if the memory block may be valid, false (zero)
if it is definitely invalid.
Note that, depending on architecture, this function probably just
checks that the pointer is in the user space range - after calling this
function, memory access functions may still return -EFAULT.