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/8.3/sys/compat/linux/linux_fork.c 219205 2011-03-02 20:08:52Z dchagin $");
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)) != 0)
68 return (error);
69
70 td->td_retval[0] = p2->p_pid;
71 td->td_retval[1] = 0;
72
73 error = linux_proc_init(td, td->td_retval[0], 0);
74 if (error)
75 return (error);
76
77 td2 = FIRST_THREAD_IN_PROC(p2);
78
79 /*
80 * Make this runnable after we are finished with it.
81 */
82 thread_lock(td2);
83 TD_SET_CAN_RUN(td2);
84 sched_add(td2, SRQ_BORING);
85 thread_unlock(td2);
86
87 return (0);
88 }
89
90 int
91 linux_vfork(struct thread *td, struct linux_vfork_args *args)
92 {
93 int error;
94 struct proc *p2;
95 struct thread *td2;
96
97 #ifdef DEBUG
98 if (ldebug(vfork))
99 printf(ARGS(vfork, ""));
100 #endif
101
102 /* Exclude RFPPWAIT */
103 if ((error = fork1(td, RFFDG | RFPROC | RFMEM | RFSTOPPED, 0, &p2)) != 0)
104 return (error);
105
106 td->td_retval[0] = p2->p_pid;
107
108 error = linux_proc_init(td, td->td_retval[0], 0);
109 if (error)
110 return (error);
111
112 PROC_LOCK(p2);
113 p2->p_flag |= P_PPWAIT;
114 PROC_UNLOCK(p2);
115
116 td2 = FIRST_THREAD_IN_PROC(p2);
117
118 /*
119 * Make this runnable after we are finished with it.
120 */
121 thread_lock(td2);
122 TD_SET_CAN_RUN(td2);
123 sched_add(td2, SRQ_BORING);
124 thread_unlock(td2);
125
126 /* wait for the children to exit, ie. emulate vfork */
127 PROC_LOCK(p2);
128 while (p2->p_flag & P_PPWAIT)
129 cv_wait(&p2->p_pwait, &p2->p_mtx);
130 PROC_UNLOCK(p2);
131
132 return (0);
133 }
134
135 int
136 linux_clone(struct thread *td, struct linux_clone_args *args)
137 {
138 int error, ff = RFPROC | RFSTOPPED;
139 struct proc *p2;
140 struct thread *td2;
141 int exit_signal;
142 struct linux_emuldata *em;
143
144 #ifdef DEBUG
145 if (ldebug(clone)) {
146 printf(ARGS(clone, "flags %x, stack %p, parent tid: %p, "
147 "child tid: %p"), (unsigned)args->flags,
148 args->stack, args->parent_tidptr, args->child_tidptr);
149 }
150 #endif
151
152 exit_signal = args->flags & 0x000000ff;
153 if (LINUX_SIG_VALID(exit_signal)) {
154 if (exit_signal <= LINUX_SIGTBLSZ)
155 exit_signal =
156 linux_to_bsd_signal[_SIG_IDX(exit_signal)];
157 } else if (exit_signal != 0)
158 return (EINVAL);
159
160 if (args->flags & LINUX_CLONE_VM)
161 ff |= RFMEM;
162 if (args->flags & LINUX_CLONE_SIGHAND)
163 ff |= RFSIGSHARE;
164 /*
165 * XXX: In Linux, sharing of fs info (chroot/cwd/umask)
166 * and open files is independant. In FreeBSD, its in one
167 * structure but in reality it does not cause any problems
168 * because both of these flags are usually set together.
169 */
170 if (!(args->flags & (LINUX_CLONE_FILES | LINUX_CLONE_FS)))
171 ff |= RFFDG;
172
173 /*
174 * Attempt to detect when linux_clone(2) is used for creating
175 * kernel threads. Unfortunately despite the existence of the
176 * CLONE_THREAD flag, version of linuxthreads package used in
177 * most popular distros as of beginning of 2005 doesn't make
178 * any use of it. Therefore, this detection relies on
179 * empirical observation that linuxthreads sets certain
180 * combination of flags, so that we can make more or less
181 * precise detection and notify the FreeBSD kernel that several
182 * processes are in fact part of the same threading group, so
183 * that special treatment is necessary for signal delivery
184 * between those processes and fd locking.
185 */
186 if ((args->flags & 0xffffff00) == LINUX_THREADING_FLAGS)
187 ff |= RFTHREAD;
188
189 if (args->flags & LINUX_CLONE_PARENT_SETTID)
190 if (args->parent_tidptr == NULL)
191 return (EINVAL);
192
193 error = fork1(td, ff, 0, &p2);
194 if (error)
195 return (error);
196
197 if (args->flags & (LINUX_CLONE_PARENT | LINUX_CLONE_THREAD)) {
198 sx_xlock(&proctree_lock);
199 PROC_LOCK(p2);
200 proc_reparent(p2, td->td_proc->p_pptr);
201 PROC_UNLOCK(p2);
202 sx_xunlock(&proctree_lock);
203 }
204
205 /* create the emuldata */
206 error = linux_proc_init(td, p2->p_pid, args->flags);
207 /* reference it - no need to check this */
208 em = em_find(p2, EMUL_DOLOCK);
209 KASSERT(em != NULL, ("clone: emuldata not found."));
210 /* and adjust it */
211
212 if (args->flags & LINUX_CLONE_THREAD) {
213 #ifdef notyet
214 PROC_LOCK(p2);
215 p2->p_pgrp = td->td_proc->p_pgrp;
216 PROC_UNLOCK(p2);
217 #endif
218 exit_signal = 0;
219 }
220
221 if (args->flags & LINUX_CLONE_CHILD_SETTID)
222 em->child_set_tid = args->child_tidptr;
223 else
224 em->child_set_tid = NULL;
225
226 if (args->flags & LINUX_CLONE_CHILD_CLEARTID)
227 em->child_clear_tid = args->child_tidptr;
228 else
229 em->child_clear_tid = NULL;
230
231 EMUL_UNLOCK(&emul_lock);
232
233 if (args->flags & LINUX_CLONE_PARENT_SETTID) {
234 error = copyout(&p2->p_pid, args->parent_tidptr,
235 sizeof(p2->p_pid));
236 if (error)
237 printf(LMSG("copyout failed!"));
238 }
239
240 PROC_LOCK(p2);
241 p2->p_sigparent = exit_signal;
242 PROC_UNLOCK(p2);
243 td2 = FIRST_THREAD_IN_PROC(p2);
244 /*
245 * In a case of stack = NULL, we are supposed to COW calling process
246 * stack. This is what normal fork() does, so we just keep tf_rsp arg
247 * intact.
248 */
249 if (args->stack)
250 linux_set_upcall_kse(td2, PTROUT(args->stack));
251
252 if (args->flags & LINUX_CLONE_SETTLS)
253 linux_set_cloned_tls(td2, args->tls);
254
255 #ifdef DEBUG
256 if (ldebug(clone))
257 printf(LMSG("clone: successful rfork to %d, "
258 "stack %p sig = %d"), (int)p2->p_pid, args->stack,
259 exit_signal);
260 #endif
261 if (args->flags & LINUX_CLONE_VFORK) {
262 PROC_LOCK(p2);
263 p2->p_flag |= P_PPWAIT;
264 PROC_UNLOCK(p2);
265 }
266
267 /*
268 * Make this runnable after we are finished with it.
269 */
270 thread_lock(td2);
271 TD_SET_CAN_RUN(td2);
272 sched_add(td2, SRQ_BORING);
273 thread_unlock(td2);
274
275 td->td_retval[0] = p2->p_pid;
276 td->td_retval[1] = 0;
277
278 if (args->flags & LINUX_CLONE_VFORK) {
279 /* wait for the children to exit, ie. emulate vfork */
280 PROC_LOCK(p2);
281 while (p2->p_flag & P_PPWAIT)
282 cv_wait(&p2->p_pwait, &p2->p_mtx);
283 PROC_UNLOCK(p2);
284 }
285
286 return (0);
287 }
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