NAME
__copy_from_user_inatomic - Copy a block of data from user space, with less checking.
SYNOPSIS
__always_inline unsigned long __copy_from_user_inatomic(void * to, const void __user * from, unsigned long 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.
DESCRIPTION
Copy data from user space to kernel space. Caller must check the specified block with access_ok before calling this function.
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.
An alternate version - __copy_from_user_inatomic - may be called from atomic context and will fail rather than sleep. In this case the uncopied bytes will *NOT* be padded with zeros. See fs/filemap.h for explanation of why this is needed.