1 /* $NetBSD: sysproxy.c,v 1.10 2023/07/16 23:05:53 riastradh 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 1.10 2023/07/16 23:05:53 riastradh 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 #if defined(__i386__) || defined(__x86_64__)
42 /*
43 * This file abuses the pmap abstraction to create its own statically
44 * allocated struct pmap object, even though it can't do anything
45 * useful with such a thing from userland. On x86 the struct pmap
46 * definition is private, so we have to go to extra effort to abuse it
47 * there. This should be fixed -- all of the struct pmap definitions
48 * should be private, and then rump can furnish its own fake struct
49 * pmap without clashing with anything.
50 */
51 #include <machine/pmap_private.h>
52 #endif
53
54 #define _RUMP_SYSPROXY
55 #include <rump/rumpuser.h>
56
57 #include <rump-sys/kern.h>
58
59 int
rump_init_server(const char * url)60 rump_init_server(const char *url)
61 {
62
63 return rumpuser_sp_init(url, ostype, osrelease, MACHINE);
64 }
65
66 static pid_t
hyp_getpid(void)67 hyp_getpid(void)
68 {
69
70 return curproc->p_pid;
71 }
72
73 static int
hyp_syscall(int num,void * arg,long * retval)74 hyp_syscall(int num, void *arg, long *retval)
75 {
76 register_t regrv[2] = {0, 0};
77 struct lwp *l;
78 struct sysent *callp;
79 int rv;
80
81 if (__predict_false(num >= SYS_NSYSENT))
82 return ENOSYS;
83
84 /* XXX: always uses native syscall vector */
85 callp = rump_sysent + num;
86 l = curlwp;
87 rv = sy_invoke(callp, l, (void *)arg, regrv, num);
88 retval[0] = regrv[0];
89 retval[1] = regrv[1];
90
91 /* Sanity checks (from mi_userret) */
92 LOCKDEBUG_BARRIER(NULL, 0);
93 KASSERT(l->l_nopreempt == 0);
94 PSREF_DEBUG_BARRIER();
95 KASSERT(l->l_psrefs == 0);
96
97 return rv;
98 }
99
100 static struct pmap remotepmap;
101
102 static int
hyp_rfork(void * priv,int flags,const char * comm)103 hyp_rfork(void *priv, int flags, const char *comm)
104 {
105 struct rump_spctl *spctl;
106 struct vmspace *vm;
107 struct proc *p;
108 struct lwp *l;
109 int error;
110 bool initfds;
111
112 /*
113 * If we are forking off of pid 1, initialize file descriptors.
114 */
115 l = curlwp;
116 if (l->l_proc->p_pid == 1) {
117 KASSERT(flags == RUMP_RFFD_CLEAR);
118 initfds = true;
119 } else {
120 initfds = false;
121 }
122
123 /*
124 * Since it's a proxy proc, we create a vmspace for it.
125 */
126 spctl = kmem_zalloc(sizeof(*spctl), KM_SLEEP);
127 vm = &spctl->spctl_vm;
128 uvmspace_init(vm, &remotepmap, 0, 0, false);
129 spctl->spctl = priv;
130
131 if ((error = rump_lwproc_rfork_vmspace(vm, flags)) != 0) {
132 kmem_free(vm, sizeof(*vm));
133 return error;
134 }
135
136 /*
137 * We forked in this routine, so cannot use curlwp (const)
138 */
139 l = rump_lwproc_curlwp();
140 p = l->l_proc;
141
142 if (comm)
143 strlcpy(p->p_comm, comm, sizeof(p->p_comm));
144 if (initfds)
145 rump_consdev_init();
146
147 return 0;
148 }
149
150 /*
151 * Order all lwps in a process to exit. does *not* wait for them to drain.
152 */
153 static void
hyp_lwpexit(void)154 hyp_lwpexit(void)
155 {
156 struct proc *p = curproc;
157 struct lwp *l;
158
159 mutex_enter(p->p_lock);
160 /*
161 * First pass: mark all lwps in the process with LW_RUMP_QEXIT
162 * so that they know they should exit.
163 */
164 LIST_FOREACH(l, &p->p_lwps, l_sibling) {
165 if (l == curlwp)
166 continue;
167 l->l_flag |= LW_RUMP_QEXIT;
168 }
169 mutex_exit(p->p_lock);
170
171 /*
172 * Next, make sure everyone on all CPUs sees our status
173 * update. This keeps threads inside cv_wait() and makes
174 * sure we don't access a stale cv pointer later when
175 * we wake up the threads.
176 */
177
178 xc_barrier(0);
179
180 /*
181 * Ok, all lwps are either:
182 * 1) not in the cv code
183 * 2) sleeping on l->l_sched.info
184 * 3) sleeping on p->p_waitcv
185 *
186 * Either way, l_sched.info is stable until we set
187 * PS_RUMP_LWPEXIT in p->p_sflag.
188 */
189
190 mutex_enter(p->p_lock);
191 LIST_FOREACH(l, &p->p_lwps, l_sibling) {
192 if (l->l_sched.info)
193 cv_broadcast(l->l_sched.info);
194 }
195 p->p_sflag |= PS_RUMP_LWPEXIT;
196 cv_broadcast(&p->p_waitcv);
197 mutex_exit(p->p_lock);
198 }
199
200 /*
201 * Notify process that all threads have been drained and exec is complete.
202 */
203 static void
hyp_execnotify(const char * comm)204 hyp_execnotify(const char *comm)
205 {
206 struct proc *p = curproc;
207
208 fd_closeexec();
209 mutex_enter(p->p_lock);
210 KASSERT(p->p_nlwps == 1 && p->p_sflag & PS_RUMP_LWPEXIT);
211 p->p_sflag &= ~PS_RUMP_LWPEXIT;
212 mutex_exit(p->p_lock);
213 strlcpy(p->p_comm, comm, sizeof(p->p_comm));
214 }
215
216 /*
217 * Initialize interface pointers since component is present.
218 */
RUMP_COMPONENT(RUMP_COMPONENT_KERN)219 RUMP_COMPONENT(RUMP_COMPONENT_KERN)
220 {
221
222 rump_sysproxy_ops.rspo_copyin = rumpuser_sp_copyin;
223 rump_sysproxy_ops.rspo_copyinstr = rumpuser_sp_copyinstr;
224 rump_sysproxy_ops.rspo_copyout = rumpuser_sp_copyout;
225 rump_sysproxy_ops.rspo_copyoutstr = rumpuser_sp_copyoutstr;
226 rump_sysproxy_ops.rspo_anonmmap = rumpuser_sp_anonmmap;
227 rump_sysproxy_ops.rspo_raise = rumpuser_sp_raise;
228 rump_sysproxy_ops.rspo_fini = rumpuser_sp_fini;
229
230 rump_sysproxy_ops.rspo_hyp_getpid = hyp_getpid;
231 rump_sysproxy_ops.rspo_hyp_syscall = hyp_syscall;
232 rump_sysproxy_ops.rspo_hyp_rfork = hyp_rfork;
233 rump_sysproxy_ops.rspo_hyp_lwpexit = hyp_lwpexit;
234 rump_sysproxy_ops.rspo_hyp_execnotify = hyp_execnotify;
235 }
236