from_buffer
static int from_buffer(struct st_buffer *, char __user *, int);
i = from_buffer(STbp, buf, transfer);
char *to_buffer = NULL, *from_buffer = NULL;
from_buffer = aa_get_buffer(false);
if (!to_buffer || !from_buffer)
from_path, from_buffer,
aa_put_buffer(from_buffer);