1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2004 Tim J. Robbins
5 * Copyright (c) 2002 Doug Rabson
6 * Copyright (c) 2000 Marcel Moolenaar
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer
14 * in this position and unchanged.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD: releng/12.0/sys/compat/linux/linux_fork.c 335505 2018-06-21 21:15:04Z kib $");
33
34 #include "opt_compat.h"
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/imgact.h>
39 #include <sys/ktr.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42 #include <sys/proc.h>
43 #include <sys/ptrace.h>
44 #include <sys/racct.h>
45 #include <sys/sched.h>
46 #include <sys/syscallsubr.h>
47 #include <sys/sx.h>
48 #include <sys/umtx.h>
49 #include <sys/unistd.h>
50 #include <sys/wait.h>
51
52 #include <vm/vm.h>
53 #include <vm/pmap.h>
54 #include <vm/vm_map.h>
55
56 #ifdef COMPAT_LINUX32
57 #include <machine/../linux32/linux.h>
58 #include <machine/../linux32/linux32_proto.h>
59 #else
60 #include <machine/../linux/linux.h>
61 #include <machine/../linux/linux_proto.h>
62 #endif
63 #include <compat/linux/linux_emul.h>
64 #include <compat/linux/linux_futex.h>
65 #include <compat/linux/linux_misc.h>
66 #include <compat/linux/linux_util.h>
67
68 #ifdef LINUX_LEGACY_SYSCALLS
69 int
70 linux_fork(struct thread *td, struct linux_fork_args *args)
71 {
72 struct fork_req fr;
73 int error;
74 struct proc *p2;
75 struct thread *td2;
76
77 #ifdef DEBUG
78 if (ldebug(fork))
79 printf(ARGS(fork, ""));
80 #endif
81
82 bzero(&fr, sizeof(fr));
83 fr.fr_flags = RFFDG | RFPROC | RFSTOPPED;
84 fr.fr_procp = &p2;
85 if ((error = fork1(td, &fr)) != 0)
86 return (error);
87
88 td2 = FIRST_THREAD_IN_PROC(p2);
89
90 linux_proc_init(td, td2, 0);
91
92 td->td_retval[0] = p2->p_pid;
93
94 /*
95 * Make this runnable after we are finished with it.
96 */
97 thread_lock(td2);
98 TD_SET_CAN_RUN(td2);
99 sched_add(td2, SRQ_BORING);
100 thread_unlock(td2);
101
102 return (0);
103 }
104
105 int
106 linux_vfork(struct thread *td, struct linux_vfork_args *args)
107 {
108 struct fork_req fr;
109 int error;
110 struct proc *p2;
111 struct thread *td2;
112
113 #ifdef DEBUG
114 if (ldebug(vfork))
115 printf(ARGS(vfork, ""));
116 #endif
117
118 bzero(&fr, sizeof(fr));
119 fr.fr_flags = RFFDG | RFPROC | RFMEM | RFPPWAIT | RFSTOPPED;
120 fr.fr_procp = &p2;
121 if ((error = fork1(td, &fr)) != 0)
122 return (error);
123
124 td2 = FIRST_THREAD_IN_PROC(p2);
125
126 linux_proc_init(td, td2, 0);
127
128 td->td_retval[0] = p2->p_pid;
129
130 /*
131 * Make this runnable after we are finished with it.
132 */
133 thread_lock(td2);
134 TD_SET_CAN_RUN(td2);
135 sched_add(td2, SRQ_BORING);
136 thread_unlock(td2);
137
138 return (0);
139 }
140 #endif
141
142 static int
143 linux_clone_proc(struct thread *td, struct linux_clone_args *args)
144 {
145 struct fork_req fr;
146 int error, ff = RFPROC | RFSTOPPED;
147 struct proc *p2;
148 struct thread *td2;
149 int exit_signal;
150 struct linux_emuldata *em;
151
152 #ifdef DEBUG
153 if (ldebug(clone)) {
154 printf(ARGS(clone, "flags %x, stack %p, parent tid: %p, "
155 "child tid: %p"), (unsigned)args->flags,
156 args->stack, args->parent_tidptr, args->child_tidptr);
157 }
158 #endif
159
160 exit_signal = args->flags & 0x000000ff;
161 if (LINUX_SIG_VALID(exit_signal)) {
162 exit_signal = linux_to_bsd_signal(exit_signal);
163 } else if (exit_signal != 0)
164 return (EINVAL);
165
166 if (args->flags & LINUX_CLONE_VM)
167 ff |= RFMEM;
168 if (args->flags & LINUX_CLONE_SIGHAND)
169 ff |= RFSIGSHARE;
170 /*
171 * XXX: In Linux, sharing of fs info (chroot/cwd/umask)
172 * and open files is independent. In FreeBSD, its in one
173 * structure but in reality it does not cause any problems
174 * because both of these flags are usually set together.
175 */
176 if (!(args->flags & (LINUX_CLONE_FILES | LINUX_CLONE_FS)))
177 ff |= RFFDG;
178
179 if (args->flags & LINUX_CLONE_PARENT_SETTID)
180 if (args->parent_tidptr == NULL)
181 return (EINVAL);
182
183 if (args->flags & LINUX_CLONE_VFORK)
184 ff |= RFPPWAIT;
185
186 bzero(&fr, sizeof(fr));
187 fr.fr_flags = ff;
188 fr.fr_procp = &p2;
189 error = fork1(td, &fr);
190 if (error)
191 return (error);
192
193 td2 = FIRST_THREAD_IN_PROC(p2);
194
195 /* create the emuldata */
196 linux_proc_init(td, td2, args->flags);
197
198 em = em_find(td2);
199 KASSERT(em != NULL, ("clone_proc: emuldata not found.\n"));
200
201 if (args->flags & LINUX_CLONE_CHILD_SETTID)
202 em->child_set_tid = args->child_tidptr;
203 else
204 em->child_set_tid = NULL;
205
206 if (args->flags & LINUX_CLONE_CHILD_CLEARTID)
207 em->child_clear_tid = args->child_tidptr;
208 else
209 em->child_clear_tid = NULL;
210
211 if (args->flags & LINUX_CLONE_PARENT_SETTID) {
212 error = copyout(&p2->p_pid, args->parent_tidptr,
213 sizeof(p2->p_pid));
214 if (error)
215 printf(LMSG("copyout failed!"));
216 }
217
218 PROC_LOCK(p2);
219 p2->p_sigparent = exit_signal;
220 PROC_UNLOCK(p2);
221 /*
222 * In a case of stack = NULL, we are supposed to COW calling process
223 * stack. This is what normal fork() does, so we just keep tf_rsp arg
224 * intact.
225 */
226 linux_set_upcall_kse(td2, PTROUT(args->stack));
227
228 if (args->flags & LINUX_CLONE_SETTLS)
229 linux_set_cloned_tls(td2, args->tls);
230
231 /*
232 * If CLONE_PARENT is set, then the parent of the new process will be
233 * the same as that of the calling process.
234 */
235 if (args->flags & LINUX_CLONE_PARENT) {
236 sx_xlock(&proctree_lock);
237 PROC_LOCK(p2);
238 proc_reparent(p2, td->td_proc->p_pptr);
239 PROC_UNLOCK(p2);
240 sx_xunlock(&proctree_lock);
241 }
242
243 #ifdef DEBUG
244 if (ldebug(clone))
245 printf(LMSG("clone: successful rfork to %d, "
246 "stack %p sig = %d"), (int)p2->p_pid, args->stack,
247 exit_signal);
248 #endif
249
250 /*
251 * Make this runnable after we are finished with it.
252 */
253 thread_lock(td2);
254 TD_SET_CAN_RUN(td2);
255 sched_add(td2, SRQ_BORING);
256 thread_unlock(td2);
257
258 td->td_retval[0] = p2->p_pid;
259
260 return (0);
261 }
262
263 static int
264 linux_clone_thread(struct thread *td, struct linux_clone_args *args)
265 {
266 struct linux_emuldata *em;
267 struct thread *newtd;
268 struct proc *p;
269 int error;
270
271 #ifdef DEBUG
272 if (ldebug(clone)) {
273 printf(ARGS(clone, "thread: flags %x, stack %p, parent tid: %p, "
274 "child tid: %p"), (unsigned)args->flags,
275 args->stack, args->parent_tidptr, args->child_tidptr);
276 }
277 #endif
278
279 LINUX_CTR4(clone_thread, "thread(%d) flags %x ptid %p ctid %p",
280 td->td_tid, (unsigned)args->flags,
281 args->parent_tidptr, args->child_tidptr);
282
283 if (args->flags & LINUX_CLONE_PARENT_SETTID)
284 if (args->parent_tidptr == NULL)
285 return (EINVAL);
286
287 /* Threads should be created with own stack */
288 if (args->stack == NULL)
289 return (EINVAL);
290
291 p = td->td_proc;
292
293 #ifdef RACCT
294 if (racct_enable) {
295 PROC_LOCK(p);
296 error = racct_add(p, RACCT_NTHR, 1);
297 PROC_UNLOCK(p);
298 if (error != 0)
299 return (EPROCLIM);
300 }
301 #endif
302
303 /* Initialize our td */
304 error = kern_thr_alloc(p, 0, &newtd);
305 if (error)
306 goto fail;
307
308 cpu_copy_thread(newtd, td);
309
310 bzero(&newtd->td_startzero,
311 __rangeof(struct thread, td_startzero, td_endzero));
312 bcopy(&td->td_startcopy, &newtd->td_startcopy,
313 __rangeof(struct thread, td_startcopy, td_endcopy));
314
315 newtd->td_proc = p;
316 thread_cow_get(newtd, td);
317
318 /* create the emuldata */
319 linux_proc_init(td, newtd, args->flags);
320
321 em = em_find(newtd);
322 KASSERT(em != NULL, ("clone_thread: emuldata not found.\n"));
323
324 if (args->flags & LINUX_CLONE_SETTLS)
325 linux_set_cloned_tls(newtd, args->tls);
326
327 if (args->flags & LINUX_CLONE_CHILD_SETTID)
328 em->child_set_tid = args->child_tidptr;
329 else
330 em->child_set_tid = NULL;
331
332 if (args->flags & LINUX_CLONE_CHILD_CLEARTID)
333 em->child_clear_tid = args->child_tidptr;
334 else
335 em->child_clear_tid = NULL;
336
337 cpu_thread_clean(newtd);
338
339 linux_set_upcall_kse(newtd, PTROUT(args->stack));
340
341 PROC_LOCK(p);
342 p->p_flag |= P_HADTHREADS;
343 bcopy(p->p_comm, newtd->td_name, sizeof(newtd->td_name));
344
345 if (args->flags & LINUX_CLONE_PARENT)
346 thread_link(newtd, p->p_pptr);
347 else
348 thread_link(newtd, p);
349
350 thread_lock(td);
351 /* let the scheduler know about these things. */
352 sched_fork_thread(td, newtd);
353 thread_unlock(td);
354 if (P_SHOULDSTOP(p))
355 newtd->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
356
357 if (p->p_ptevents & PTRACE_LWP)
358 newtd->td_dbgflags |= TDB_BORN;
359 PROC_UNLOCK(p);
360
361 tidhash_add(newtd);
362
363 #ifdef DEBUG
364 if (ldebug(clone))
365 printf(ARGS(clone, "successful clone to %d, stack %p"),
366 (int)newtd->td_tid, args->stack);
367 #endif
368
369 LINUX_CTR2(clone_thread, "thread(%d) successful clone to %d",
370 td->td_tid, newtd->td_tid);
371
372 if (args->flags & LINUX_CLONE_PARENT_SETTID) {
373 error = copyout(&newtd->td_tid, args->parent_tidptr,
374 sizeof(newtd->td_tid));
375 if (error)
376 printf(LMSG("clone_thread: copyout failed!"));
377 }
378
379 /*
380 * Make this runnable after we are finished with it.
381 */
382 thread_lock(newtd);
383 TD_SET_CAN_RUN(newtd);
384 sched_add(newtd, SRQ_BORING);
385 thread_unlock(newtd);
386
387 td->td_retval[0] = newtd->td_tid;
388
389 return (0);
390
391 fail:
392 #ifdef RACCT
393 if (racct_enable) {
394 PROC_LOCK(p);
395 racct_sub(p, RACCT_NTHR, 1);
396 PROC_UNLOCK(p);
397 }
398 #endif
399 return (error);
400 }
401
402 int
403 linux_clone(struct thread *td, struct linux_clone_args *args)
404 {
405
406 if (args->flags & LINUX_CLONE_THREAD)
407 return (linux_clone_thread(td, args));
408 else
409 return (linux_clone_proc(td, args));
410 }
411
412 int
413 linux_exit(struct thread *td, struct linux_exit_args *args)
414 {
415 struct linux_emuldata *em;
416
417 em = em_find(td);
418 KASSERT(em != NULL, ("exit: emuldata not found.\n"));
419
420 LINUX_CTR2(exit, "thread(%d) (%d)", em->em_tid, args->rval);
421
422 umtx_thread_exit(td);
423
424 linux_thread_detach(td);
425
426 /*
427 * XXX. When the last two threads of a process
428 * exit via pthread_exit() try thr_exit() first.
429 */
430 kern_thr_exit(td);
431 exit1(td, args->rval, 0);
432 /* NOTREACHED */
433 }
434
435 int
436 linux_set_tid_address(struct thread *td, struct linux_set_tid_address_args *args)
437 {
438 struct linux_emuldata *em;
439
440 em = em_find(td);
441 KASSERT(em != NULL, ("set_tid_address: emuldata not found.\n"));
442
443 em->child_clear_tid = args->tidptr;
444
445 td->td_retval[0] = em->em_tid;
446
447 LINUX_CTR3(set_tid_address, "tidptr(%d) %p, returns %d",
448 em->em_tid, args->tidptr, td->td_retval[0]);
449
450 return (0);
451 }
452
453 void
454 linux_thread_detach(struct thread *td)
455 {
456 struct linux_sys_futex_args cup;
457 struct linux_emuldata *em;
458 int *child_clear_tid;
459 int error;
460
461 em = em_find(td);
462 KASSERT(em != NULL, ("thread_detach: emuldata not found.\n"));
463
464 LINUX_CTR1(thread_detach, "thread(%d)", em->em_tid);
465
466 release_futexes(td, em);
467
468 child_clear_tid = em->child_clear_tid;
469
470 if (child_clear_tid != NULL) {
471
472 LINUX_CTR2(thread_detach, "thread(%d) %p",
473 em->em_tid, child_clear_tid);
474
475 error = suword32(child_clear_tid, 0);
476 if (error != 0)
477 return;
478
479 cup.uaddr = child_clear_tid;
480 cup.op = LINUX_FUTEX_WAKE;
481 cup.val = 1; /* wake one */
482 cup.timeout = NULL;
483 cup.uaddr2 = NULL;
484 cup.val3 = 0;
485 error = linux_sys_futex(td, &cup);
486 /*
487 * this cannot happen at the moment and if this happens it
488 * probably means there is a user space bug
489 */
490 if (error != 0)
491 linux_msg(td, "futex stuff in thread_detach failed.");
492 }
493 }
Cache object: 1d99007594d32adb3624526f3d373d2f
|