Hello everybody !
I needed to implement an IPC connectiovity between module and
userspace daemon, and came to this horrible code (after looking to
sys_msgsnd() ):
...
copy_to_user(msg_buf, &hlb1, sizeof(struct linfs_buffer));
hi1 = sys_ipc(MSGSND, msgq_id, message_size, 0, \
(struct msgbuf *)msg_buf, 0);
...
msg_buf is in userspace, hlb1 - module's prepared message (struct msgbuf ).
Well, it works :) . Messages are delivered,
but the whole construction looks rather ugly. The worst part of it is
sys_msgsnd() does then copy_from_user to kmalloc()'ed buffer, just to enqueue
message. Can somebody tell me, is there any other way to implement IPC
functionality , without rewriting sys_msgsnd() and accompanying functions
(load_msg etc.) inside of my module ?
With all the best, yarick at relex dot ru