2 * Copyright (c) 2003 Galen Sampson <galen_sampson@yahoo.com>
3 * Copyright (c) 2003 Matthew Dillon <dillon@backplane.com>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * $DragonFly: src/lib/libcaps/sysport.c,v 1.4 2004/07/29 08:55:02 dillon Exp $
32 #include <sys/syscall.h>
33 #include <sys/sysproto.h>
34 #include <sys/sysunion.h>
43 static int sysport_putport(lwkt_port_t port, lwkt_msg_t msg);
44 static void sysport_loop(void *dummy);
52 lwkt_init_thread(&sys_td, libcaps_alloc_stack(LWKT_THREAD_STACK),
53 LWKT_THREAD_STACK, TDF_SYSTHREAD, mycpu);
54 sysport = &sys_td.td_msgport;
55 sysport->mp_putport = sysport_putport;
56 sysport->mp_flags = MSGPORTF_WAITING; /* XXX temporary */
57 cpu_set_thread_handler(&sys_td, lwkt_exit, sysport_loop, NULL);
60 /************************************************************************
62 ************************************************************************/
65 * XXX We might need to separte this function in the way *lwkt_putport*
66 * is separated in the case of multiple cpus. Secifically we will need
67 * a lwkt_sysputport_remote().
71 sysport_putport(lwkt_port_t port, lwkt_msg_t msg)
74 thread_t td = port->mp_td;
77 * XXX sendsys() will only allow asynchronous messages from uid 0. This
78 * is a kernel issue. See note below.
80 if(msg->ms_flags & MSGF_ASYNC)
83 * The message is not done.
85 msg->ms_flags &= ~MSGF_DONE;
86 error = sendsys(NULL, msg, msg->ms_msgsize);
89 TAILQ_INSERT_TAIL(&port->mp_msgq, msg, ms_node);
90 msg->ms_flags |= MSGF_QUEUED;
92 * Shouldn't need this check, we are always waiting
94 if(port->mp_flags & MSGPORTF_WAITING)
100 printf("async return error %d\n", error);
105 * XXX this is a temporary hack until the kernel changes to implement
106 * the desired asynchronous goals.
108 * The current asynchronous messaging systemcall interface that sendsys
109 * uses has some potential security issues and is limited to use by the
110 * superuser only. Synchronous messages are allowed by anyone. Sendsys
111 * returns EPERM in the case where you are not the superuser but tried to
112 * send an asynchonous message.
114 * If you are not the super user then the system call will be made again,
115 * but without MSGF_ASYNC set.
117 if(error != EASYNC && error == EPERM)
119 msg->ms_flags &= ~MSGF_ASYNC;
121 printf("Warning, only super user can send asynchonous system messages\n");
126 * The message is synchronous. Send it sychronously.
128 if((msg->ms_flags & MSGF_ASYNC) == 0)
130 error = sendsys(NULL, msg, msg->ms_msgsize);
131 msg->ms_flags |= MSGF_DONE;
138 lwkt_syswaitport(lwkt_msg_t msg)
143 * Block awaiting a return from the kernel.
145 for(rmsg = (lwkt_msg_t)sendsys(NULL, NULL, -1); rmsg != msg; )
147 usleep(1000000 / 10);
148 rmsg = (lwkt_msg_t)sendsys(NULL, NULL, -1);
150 printf(" rmsg %p\n", rmsg);
157 /************************************************************************
159 ************************************************************************/
161 * XXX Temporary function that provides a mechanism to return an asynchronous
162 * message completed by the kernel to be returned to the port it originated
167 sysport_loop(void *dummy)
173 msg = lwkt_waitport(&curthread->td_msgport, NULL);
175 msg = lwkt_syswaitport(msg);
178 * The message was asynchronous
180 if(msg->ms_flags & MSGF_ASYNC)
182 lwkt_replymsg(msg, msg->ms_error);
186 msg->ms_flags |= MSGF_DONE;