xref: /netbsd-src/sys/rump/kern/lib/libsysproxy/sysproxy.c (revision 76c7fc5f6b13ed0b1508e6b313e88e59977ed78e)
1 /*	$NetBSD: sysproxy.c,v 1.8 2019/10/06 15:11:17 uwe Exp $	*/
2 
3 /*
4  * Copyright (c) 2010, 2011 Antti Kantee.  All Rights Reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
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.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
16  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18  * 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 OR
21  * 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
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: sysproxy.c,v 1.8 2019/10/06 15:11:17 uwe Exp $");
30 
31 #include <sys/param.h>
32 #include <sys/filedesc.h>
33 #include <sys/kmem.h>
34 #include <sys/syscall.h>
35 #include <sys/syscallvar.h>
36 #include <sys/systm.h>
37 #include <sys/xcall.h>
38 #include <sys/lockdebug.h>
39 #include <sys/psref.h>
40 
41 #define _RUMP_SYSPROXY
42 #include <rump/rumpuser.h>
43 
44 #include <rump-sys/kern.h>
45 
46 int
47 rump_init_server(const char *url)
48 {
49 
50 	return rumpuser_sp_init(url, ostype, osrelease, MACHINE);
51 }
52 
53 static pid_t
54 hyp_getpid(void)
55 {
56 
57 	return curproc->p_pid;
58 }
59 
60 static int
61 hyp_syscall(int num, void *arg, long *retval)
62 {
63 	register_t regrv[2] = {0, 0};
64 	struct lwp *l;
65 	struct sysent *callp;
66 	int rv;
67 
68 	if (__predict_false(num >= SYS_NSYSENT))
69 		return ENOSYS;
70 
71 	/* XXX: always uses native syscall vector */
72 	callp = rump_sysent + num;
73 	l = curlwp;
74 	rv = sy_invoke(callp, l, (void *)arg, regrv, num);
75 	retval[0] = regrv[0];
76 	retval[1] = regrv[1];
77 
78 	/* Sanity checks (from mi_userret) */
79 	LOCKDEBUG_BARRIER(NULL, 0);
80 	KASSERT(l->l_nopreempt == 0);
81 	PSREF_DEBUG_BARRIER();
82 	KASSERT(l->l_psrefs == 0);
83 
84 	return rv;
85 }
86 
87 static struct pmap remotepmap;
88 
89 static int
90 hyp_rfork(void *priv, int flags, const char *comm)
91 {
92 	struct rump_spctl *spctl;
93 	struct vmspace *vm;
94 	struct proc *p;
95 	struct lwp *l;
96 	int error;
97 	bool initfds;
98 
99 	/*
100 	 * If we are forking off of pid 1, initialize file descriptors.
101 	 */
102 	l = curlwp;
103 	if (l->l_proc->p_pid == 1) {
104 		KASSERT(flags == RUMP_RFFD_CLEAR);
105 		initfds = true;
106 	} else {
107 		initfds = false;
108 	}
109 
110 	/*
111 	 * Since it's a proxy proc, we create a vmspace for it.
112 	 */
113 	spctl = kmem_zalloc(sizeof(*spctl), KM_SLEEP);
114 	vm = &spctl->spctl_vm;
115 	uvmspace_init(vm, &remotepmap, 0, 0, false);
116 	spctl->spctl = priv;
117 
118 	if ((error = rump_lwproc_rfork_vmspace(vm, flags)) != 0) {
119 		kmem_free(vm, sizeof(*vm));
120 		return error;
121 	}
122 
123 	/*
124 	 * We forked in this routine, so cannot use curlwp (const)
125 	 */
126 	l = rump_lwproc_curlwp();
127 	p = l->l_proc;
128 
129 	if (comm)
130 		strlcpy(p->p_comm, comm, sizeof(p->p_comm));
131 	if (initfds)
132 		rump_consdev_init();
133 
134 	return 0;
135 }
136 
137 /*
138  * Order all lwps in a process to exit.  does *not* wait for them to drain.
139  */
140 static void
141 hyp_lwpexit(void)
142 {
143 	struct proc *p = curproc;
144 	struct lwp *l;
145 
146 	mutex_enter(p->p_lock);
147 	/*
148 	 * First pass: mark all lwps in the process with LW_RUMP_QEXIT
149 	 * so that they know they should exit.
150 	 */
151 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
152 		if (l == curlwp)
153 			continue;
154 		l->l_flag |= LW_RUMP_QEXIT;
155 	}
156 	mutex_exit(p->p_lock);
157 
158 	/*
159 	 * Next, make sure everyone on all CPUs sees our status
160 	 * update.  This keeps threads inside cv_wait() and makes
161 	 * sure we don't access a stale cv pointer later when
162 	 * we wake up the threads.
163 	 */
164 
165 	xc_barrier(0);
166 
167 	/*
168 	 * Ok, all lwps are either:
169 	 *  1) not in the cv code
170 	 *  2) sleeping on l->l_private
171 	 *  3) sleeping on p->p_waitcv
172 	 *
173 	 * Either way, l_private is stable until we set PS_RUMP_LWPEXIT
174 	 * in p->p_sflag.
175 	 */
176 
177 	mutex_enter(p->p_lock);
178 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
179 		if (l->l_private)
180 			cv_broadcast(l->l_private);
181 	}
182 	p->p_sflag |= PS_RUMP_LWPEXIT;
183 	cv_broadcast(&p->p_waitcv);
184 	mutex_exit(p->p_lock);
185 }
186 
187 /*
188  * Notify process that all threads have been drained and exec is complete.
189  */
190 static void
191 hyp_execnotify(const char *comm)
192 {
193 	struct proc *p = curproc;
194 
195 	fd_closeexec();
196 	mutex_enter(p->p_lock);
197 	KASSERT(p->p_nlwps == 1 && p->p_sflag & PS_RUMP_LWPEXIT);
198 	p->p_sflag &= ~PS_RUMP_LWPEXIT;
199 	mutex_exit(p->p_lock);
200 	strlcpy(p->p_comm, comm, sizeof(p->p_comm));
201 }
202 
203 /*
204  * Initialize interface pointers since component is present.
205  */
206 RUMP_COMPONENT(RUMP_COMPONENT_KERN)
207 {
208 
209 	rump_sysproxy_ops.rspo_copyin		= rumpuser_sp_copyin;
210 	rump_sysproxy_ops.rspo_copyinstr	= rumpuser_sp_copyinstr;
211 	rump_sysproxy_ops.rspo_copyout		= rumpuser_sp_copyout;
212 	rump_sysproxy_ops.rspo_copyoutstr	= rumpuser_sp_copyoutstr;
213 	rump_sysproxy_ops.rspo_anonmmap		= rumpuser_sp_anonmmap;
214 	rump_sysproxy_ops.rspo_raise		= rumpuser_sp_raise;
215 	rump_sysproxy_ops.rspo_fini		= rumpuser_sp_fini;
216 
217 	rump_sysproxy_ops.rspo_hyp_getpid	= hyp_getpid;
218 	rump_sysproxy_ops.rspo_hyp_syscall	= hyp_syscall;
219 	rump_sysproxy_ops.rspo_hyp_rfork	= hyp_rfork;
220 	rump_sysproxy_ops.rspo_hyp_lwpexit	= hyp_lwpexit;
221 	rump_sysproxy_ops.rspo_hyp_execnotify	= hyp_execnotify;
222 }
223