Very Computer

Hi,
I'm wondering if (how) it's possible to use some sort of InterProcess
Communication between a process in kernelspace and one in userspace?

Perhaps I could use a pipe for this?

Thanks in advance //
J. Andersson

System V IPC?

Geoff

Have a look at linux/fs/nfs in the file inode.c:

/*
 * The way this works is that the mount process passes a structure
 * in the data argument which contains an open socket to the NFS
 * server and the root file handle obtained from the server's mount
 * daemon.  We stash these away in the private superblock fields.
 * Later we can add other mount parameters like caching values.
 */

struct super_block *nfs_read_super(struct super_block *sb, void
*raw_data,int silent)

The handling for a UNIX socket or a pipe should be similar.

G'day,
sjames

: Hi,
: I'm wondering if (how) it's possible to use some sort of InterProcess
: Communication between a process in kernelspace and one in userspace?

The usual way is to create a character device driver and use the device for
kernel/user level communication. The user level side of things opens the
device and reads/writes data over it. The kernel has plenty of examples in
drivers/char/

In 2.1 there is a very elegant alternative too: a netlink socket. netlink
has the advantage that it already implements all code for pseudo reliable
delivery - you just pass it a buffer and netlink does the rest. With a device
you have to do your own queue management.

-Andi