hi,
I want to write a simple network client server inside kernel(2.6.22). I know
that this should not be done in kernel, however, this is a research project
and I just wanted to compare a few things. I was using sock_create() to
create a socket. This call returns an allocated struct socket upon
successful completion. However, now I want to use sys_poll() to poll the
socket to check if the data is available. Since I need fd for this, I was
thinking about recompiling kernel with exported sock_map_fd() (and
sock_poll()) and using that to get an fd.
My questions:
1. I assume that usually when a socket is created from user level process,
sock_map_fd() will allocate an fd from table that is associated with that
user level process. However, in this case, my kernel thread is not
associated with any process. Would it be still safe to call sock_map_fd(),
get an fd and call sys_poll() on it?
2. In the latest kernel (2.6.30), I see that most of the system calls are
defined using SYSCALL_DEFINEN() macro. What is the reason in doing so? Can
one still use system calls defined in this way inside the kernel?
In general, why system calls are hidden from kernel processes?
