1 /*-
2 * Copyright (c) 2004 Tim J. Robbins
3 * Copyright (c) 2002 Doug Rabson
4 * Copyright (c) 2000 Marcel Moolenaar
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer
12 * in this position and unchanged.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: releng/9.1/sys/compat/linux/linux_fork.c 224987 2011-08-18 22:51:30Z jonathan $");
31
32 #include "opt_compat.h"
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/imgact.h>
37 #include <sys/lock.h>
38 #include <sys/mutex.h>
39 #include <sys/proc.h>
40 #include <sys/sched.h>
41 #include <sys/sx.h>
42 #include <sys/unistd.h>
43
44 #ifdef COMPAT_LINUX32
45 #include <machine/../linux32/linux.h>
46 #include <machine/../linux32/linux32_proto.h>
47 #else
48 #include <machine/../linux/linux.h>
49 #include <machine/../linux/linux_proto.h>
50 #endif
51 #include <compat/linux/linux_signal.h>
52 #include <compat/linux/linux_emul.h>
53
54
55 int
56 linux_fork(struct thread *td, struct linux_fork_args *args)
57 {
58 int error;
59 struct proc *p2;
60 struct thread *td2;
61
62 #ifdef DEBUG
63 if (ldebug(fork))
64 printf(ARGS(fork, ""));
65 #endif
66
67 if ((error = fork1(td, RFFDG | RFPROC | RFSTOPPED, 0, &p2, NULL, 0))
68 != 0)
69 return (error);
70
71 td->td_retval[0] = p2->p_pid;
72 td->td_retval[1] = 0;
73
74 error = linux_proc_init(td, td->td_retval[0], 0);
75 if (error)
76 return (error);
77
78 td2 = FIRST_THREAD_IN_PROC(p2);
79
80 /*
81 * Make this runnable after we are finished with it.
82 */
83 thread_lock(td2);
84 TD_SET_CAN_RUN(td2);
85 sched_add(td2, SRQ_BORING);
86 thread_unlock(td2);
87
88 return (0);
89 }
90
91 int
92 linux_vfork(struct thread *td, struct linux_vfork_args *args)
93 {
94 int error;
95 struct proc *p2;
96 struct thread *td2;
97
98 #ifdef DEBUG
99 if (ldebug(vfork))
100 printf(ARGS(vfork, ""));
101 #endif
102
103 /* Exclude RFPPWAIT */
104 if ((error = fork1(td, RFFDG | RFPROC | RFMEM | RFSTOPPED, 0, &p2,
105 NULL, 0)) != 0)
106 return (error);
107
108 td->td_retval[0] = p2->p_pid;
109
110 error = linux_proc_init(td, td->td_retval[0], 0);
111 if (error)
112 return (error);
113
114 PROC_LOCK(p2);
115 p2->p_flag |= P_PPWAIT;
116 PROC_UNLOCK(p2);
117
118 td2 = FIRST_THREAD_IN_PROC(p2);
119
120 /*
121 * Make this runnable after we are finished with it.
122 */
123 thread_lock(td2);
124 TD_SET_CAN_RUN(td2);
125 sched_add(td2, SRQ_BORING);
126 thread_unlock(td2);
127
128 /* wait for the children to exit, ie. emulate vfork */
129 PROC_LOCK(p2);
130 while (p2->p_flag & P_PPWAIT)
131 cv_wait(&p2->p_pwait, &p2->p_mtx);
132 PROC_UNLOCK(p2);
133
134 return (0);
135 }
136
137 int
138 linux_clone(struct thread *td, struct linux_clone_args *args)
139 {
140 int error, ff = RFPROC | RFSTOPPED;
141 struct proc *p2;
142 struct thread *td2;
143 int exit_signal;
144 struct linux_emuldata *em;
145
146 #ifdef DEBUG
147 if (ldebug(clone)) {
148 printf(ARGS(clone, "flags %x, stack %p, parent tid: %p, "
149 "child tid: %p"), (unsigned)args->flags,
150 args->stack, args->parent_tidptr, args->child_tidptr);
151 }
152 #endif
153
154 exit_signal = args->flags & 0x000000ff;
155 if (LINUX_SIG_VALID(exit_signal)) {
156 if (exit_signal <= LINUX_SIGTBLSZ)
157 exit_signal =
158 linux_to_bsd_signal[_SIG_IDX(exit_signal)];
159 } else if (exit_signal != 0)
160 return (EINVAL);
161
162 if (args->flags & LINUX_CLONE_VM)
163 ff |= RFMEM;
164 if (args->flags & LINUX_CLONE_SIGHAND)
165 ff |= RFSIGSHARE;
166 /*
167 * XXX: In Linux, sharing of fs info (chroot/cwd/umask)
168 * and open files is independant. In FreeBSD, its in one
169 * structure but in reality it does not cause any problems
170 * because both of these flags are usually set together.
171 */
172 if (!(args->flags & (LINUX_CLONE_FILES | LINUX_CLONE_FS)))
173 ff |= RFFDG;
174
175 /*
176 * Attempt to detect when linux_clone(2) is used for creating
177 * kernel threads. Unfortunately despite the existence of the
178 * CLONE_THREAD flag, version of linuxthreads package used in
179 * most popular distros as of beginning of 2005 doesn't make
180 * any use of it. Therefore, this detection relies on
181 * empirical observation that linuxthreads sets certain
182 * combination of flags, so that we can make more or less
183 * precise detection and notify the FreeBSD kernel that several
184 * processes are in fact part of the same threading group, so
185 * that special treatment is necessary for signal delivery
186 * between those processes and fd locking.
187 */
188 if ((args->flags & 0xffffff00) == LINUX_THREADING_FLAGS)
189 ff |= RFTHREAD;
190
191 if (args->flags & LINUX_CLONE_PARENT_SETTID)
192 if (args->parent_tidptr == NULL)
193 return (EINVAL);
194
195 error = fork1(td, ff, 0, &p2, NULL, 0);
196 if (error)
197 return (error);
198
199 if (args->flags & (LINUX_CLONE_PARENT | LINUX_CLONE_THREAD)) {
200 sx_xlock(&proctree_lock);
201 PROC_LOCK(p2);
202 proc_reparent(p2, td->td_proc->p_pptr);
203 PROC_UNLOCK(p2);
204 sx_xunlock(&proctree_lock);
205 }
206
207 /* create the emuldata */
208 error = linux_proc_init(td, p2->p_pid, args->flags);
209 /* reference it - no need to check this */
210 em = em_find(p2, EMUL_DOLOCK);
211 KASSERT(em != NULL, ("clone: emuldata not found."));
212 /* and adjust it */
213
214 if (args->flags & LINUX_CLONE_THREAD) {
215 #ifdef notyet
216 PROC_LOCK(p2);
217 p2->p_pgrp = td->td_proc->p_pgrp;
218 PROC_UNLOCK(p2);
219 #endif
220 exit_signal = 0;
221 }
222
223 if (args->flags & LINUX_CLONE_CHILD_SETTID)
224 em->child_set_tid = args->child_tidptr;
225 else
226 em->child_set_tid = NULL;
227
228 if (args->flags & LINUX_CLONE_CHILD_CLEARTID)
229 em->child_clear_tid = args->child_tidptr;
230 else
231 em->child_clear_tid = NULL;
232
233 EMUL_UNLOCK(&emul_lock);
234
235 if (args->flags & LINUX_CLONE_PARENT_SETTID) {
236 error = copyout(&p2->p_pid, args->parent_tidptr,
237 sizeof(p2->p_pid));
238 if (error)
239 printf(LMSG("copyout failed!"));
240 }
241
242 PROC_LOCK(p2);
243 p2->p_sigparent = exit_signal;
244 PROC_UNLOCK(p2);
245 td2 = FIRST_THREAD_IN_PROC(p2);
246 /*
247 * In a case of stack = NULL, we are supposed to COW calling process
248 * stack. This is what normal fork() does, so we just keep tf_rsp arg
249 * intact.
250 */
251 if (args->stack)
252 linux_set_upcall_kse(td2, PTROUT(args->stack));
253
254 if (args->flags & LINUX_CLONE_SETTLS)
255 linux_set_cloned_tls(td2, args->tls);
256
257 #ifdef DEBUG
258 if (ldebug(clone))
259 printf(LMSG("clone: successful rfork to %d, "
260 "stack %p sig = %d"), (int)p2->p_pid, args->stack,
261 exit_signal);
262 #endif
263 if (args->flags & LINUX_CLONE_VFORK) {
264 PROC_LOCK(p2);
265 p2->p_flag |= P_PPWAIT;
266 PROC_UNLOCK(p2);
267 }
268
269 /*
270 * Make this runnable after we are finished with it.
271 */
272 thread_lock(td2);
273 TD_SET_CAN_RUN(td2);
274 sched_add(td2, SRQ_BORING);
275 thread_unlock(td2);
276
277 td->td_retval[0] = p2->p_pid;
278 td->td_retval[1] = 0;
279
280 if (args->flags & LINUX_CLONE_VFORK) {
281 /* wait for the children to exit, ie. emulate vfork */
282 PROC_LOCK(p2);
283 while (p2->p_flag & P_PPWAIT)
284 cv_wait(&p2->p_pwait, &p2->p_mtx);
285 PROC_UNLOCK(p2);
286 }
287
288 return (0);
289 }
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