xref: /netbsd-src/sys/rump/kern/lib/libsysproxy/sysproxy.c (revision f3cfa6f6ce31685c6c4a758bc430e69eb99f50a4)
1 /*	$NetBSD: sysproxy.c,v 1.7 2019/05/17 03:34:26 ozaki-r 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 1.7 2019/05/17 03:34:26 ozaki-r 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 	uint64_t where;
145 	struct lwp *l;
146 
147 	mutex_enter(p->p_lock);
148 	/*
149 	 * First pass: mark all lwps in the process with LW_RUMP_QEXIT
150 	 * so that they know they should exit.
151 	 */
152 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
153 		if (l == curlwp)
154 			continue;
155 		l->l_flag |= LW_RUMP_QEXIT;
156 	}
157 	mutex_exit(p->p_lock);
158 
159 	/*
160 	 * Next, make sure everyone on all CPUs sees our status
161 	 * update.  This keeps threads inside cv_wait() and makes
162 	 * sure we don't access a stale cv pointer later when
163 	 * we wake up the threads.
164 	 */
165 
166 	where = xc_broadcast(0, (xcfunc_t)nullop, NULL, NULL);
167 	xc_wait(where);
168 
169 	/*
170 	 * Ok, all lwps are either:
171 	 *  1) not in the cv code
172 	 *  2) sleeping on l->l_private
173 	 *  3) sleeping on p->p_waitcv
174 	 *
175 	 * Either way, l_private is stable until we set PS_RUMP_LWPEXIT
176 	 * in p->p_sflag.
177 	 */
178 
179 	mutex_enter(p->p_lock);
180 	LIST_FOREACH(l, &p->p_lwps, l_sibling) {
181 		if (l->l_private)
182 			cv_broadcast(l->l_private);
183 	}
184 	p->p_sflag |= PS_RUMP_LWPEXIT;
185 	cv_broadcast(&p->p_waitcv);
186 	mutex_exit(p->p_lock);
187 }
188 
189 /*
190  * Notify process that all threads have been drained and exec is complete.
191  */
192 static void
193 hyp_execnotify(const char *comm)
194 {
195 	struct proc *p = curproc;
196 
197 	fd_closeexec();
198 	mutex_enter(p->p_lock);
199 	KASSERT(p->p_nlwps == 1 && p->p_sflag & PS_RUMP_LWPEXIT);
200 	p->p_sflag &= ~PS_RUMP_LWPEXIT;
201 	mutex_exit(p->p_lock);
202 	strlcpy(p->p_comm, comm, sizeof(p->p_comm));
203 }
204 
205 /*
206  * Initialize interface pointers since component is present.
207  */
208 RUMP_COMPONENT(RUMP_COMPONENT_KERN)
209 {
210 
211 	rump_sysproxy_ops.rspo_copyin		= rumpuser_sp_copyin;
212 	rump_sysproxy_ops.rspo_copyinstr	= rumpuser_sp_copyinstr;
213 	rump_sysproxy_ops.rspo_copyout		= rumpuser_sp_copyout;
214 	rump_sysproxy_ops.rspo_copyoutstr	= rumpuser_sp_copyoutstr;
215 	rump_sysproxy_ops.rspo_anonmmap		= rumpuser_sp_anonmmap;
216 	rump_sysproxy_ops.rspo_raise		= rumpuser_sp_raise;
217 	rump_sysproxy_ops.rspo_fini		= rumpuser_sp_fini;
218 
219 	rump_sysproxy_ops.rspo_hyp_getpid	= hyp_getpid;
220 	rump_sysproxy_ops.rspo_hyp_syscall	= hyp_syscall;
221 	rump_sysproxy_ops.rspo_hyp_rfork	= hyp_rfork;
222 	rump_sysproxy_ops.rspo_hyp_lwpexit	= hyp_lwpexit;
223 	rump_sysproxy_ops.rspo_hyp_execnotify	= hyp_execnotify;
224 }
225