1/*
2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
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 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
| 1/*
2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
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 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
|
40 */
41
42#include "opt_compat.h"
43#include "opt_ktrace.h"
44
45#include <sys/param.h>
46#include <sys/systm.h>
47#include <sys/sysproto.h>
48#include <sys/kernel.h>
49#include <sys/malloc.h>
50#include <sys/lock.h>
51#include <sys/mutex.h>
52#include <sys/proc.h>
53#include <sys/pioctl.h>
54#include <sys/tty.h>
55#include <sys/wait.h>
56#include <sys/vmmeter.h>
57#include <sys/vnode.h>
58#include <sys/resourcevar.h>
59#include <sys/signalvar.h>
60#include <sys/sx.h>
61#include <sys/ptrace.h>
62#include <sys/acct.h> /* for acct_process() function prototype */
63#include <sys/filedesc.h>
64#include <sys/shm.h>
65#include <sys/sem.h>
66#include <sys/jail.h>
67#ifdef KTRACE
68#include <sys/ktrace.h>
69#endif
70
71#include <vm/vm.h>
72#include <vm/vm_extern.h>
73#include <vm/vm_param.h>
74#include <vm/pmap.h>
75#include <vm/vm_map.h>
76#include <vm/uma.h>
77#include <sys/user.h>
78
79/* Required to be non-static for SysVR4 emulator */
80MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status");
81
82static MALLOC_DEFINE(M_ATEXIT, "atexit", "atexit callback");
83
84static int wait1(struct thread *, struct wait_args *, int);
85
86/*
87 * callout list for things to do at exit time
88 */
89struct exitlist {
90 exitlist_fn function;
91 TAILQ_ENTRY(exitlist) next;
92};
93
94TAILQ_HEAD(exit_list_head, exitlist);
95static struct exit_list_head exit_list = TAILQ_HEAD_INITIALIZER(exit_list);
96
97/*
98 * exit --
99 * Death of process.
100 *
101 * MPSAFE
102 */
103void
104sys_exit(td, uap)
105 struct thread *td;
106 struct sys_exit_args /* {
107 int rval;
108 } */ *uap;
109{
110
111 mtx_lock(&Giant);
112 exit1(td, W_EXITCODE(uap->rval, 0));
113 /* NOTREACHED */
114}
115
116/*
117 * Exit: deallocate address space and other resources, change proc state
118 * to zombie, and unlink proc from allproc and parent's lists. Save exit
119 * status and rusage for wait(). Check for child processes and orphan them.
120 */
121void
122exit1(td, rv)
123 register struct thread *td;
124 int rv;
125{
126 struct exitlist *ep;
127 struct proc *p, *nq, *q;
128 struct tty *tp;
129 struct vnode *ttyvp;
130 register struct vmspace *vm;
131 struct vnode *vtmp;
132#ifdef KTRACE
133 struct vnode *tracevp;
134#endif
135
136 GIANT_REQUIRED;
137
138 p = td->td_proc;
139 if (p == initproc) {
140 printf("init died (signal %d, exit %d)\n",
141 WTERMSIG(rv), WEXITSTATUS(rv));
142 panic("Going nowhere without my init!");
143 }
144
145 /*
146 * XXXXKSE: MUST abort all other threads before proceeding past here.
147 */
148 PROC_LOCK(p);
149 if (p->p_flag & P_KSES) {
150 /*
151 * First check if some other thread got here before us..
152 * if so, act apropriatly, (exit or suspend);
153 */
154 thread_suspend_check(0);
155 /*
156 * Here is a trick..
157 * We need to free up our KSE to process other threads
158 * so that we can safely set the UNBOUND flag
159 * (whether or not we have a mailbox) as we are NEVER
160 * going to return to the user.
161 * The flag will not be set yet if we are exiting
162 * because of a signal, pagefault, or similar
163 * (or even an exit(2) from the UTS).
164 */
165 td->td_flags |= TDF_UNBOUND;
166
167 /*
168 * Kill off the other threads. This requires
169 * Some co-operation from other parts of the kernel
170 * so it may not be instant.
171 * With this state set:
172 * Any thread entering the kernel from userspace will
173 * thread_exit() in trap(). Any thread attempting to
174 * sleep will return immediatly
175 * with EINTR or EWOULDBLOCK, which will hopefully force them
176 * to back out to userland, freeing resources as they go, and
177 * anything attempting to return to userland will thread_exit()
178 * from userret(). thread_exit() will unsuspend us
179 * when the last other thread exits.
180 */
181 if (thread_single(SINGLE_EXIT)) {
182 panic ("Exit: Single threading fouled up");
183 }
184 /*
185 * All other activity in this process is now stopped.
186 * Remove excess KSEs and KSEGRPS. XXXKSE (when we have them)
187 * ...
188 * Turn off threading support.
189 */
190 p->p_flag &= ~P_KSES;
191 td->td_flags &= ~TDF_UNBOUND;
192 thread_single_end(); /* Don't need this any more. */
193 }
194 /*
195 * With this state set:
196 * Any thread entering the kernel from userspace will thread_exit()
197 * in trap(). Any thread attempting to sleep will return immediatly
198 * with EINTR or EWOULDBLOCK, which will hopefully force them
199 * to back out to userland, freeing resources as they go, and
200 * anything attempting to return to userland will thread_exit()
201 * from userret(). thread_exit() will do a wakeup on p->p_numthreads
202 * if it transitions to 1.
203 */
204
205 p->p_flag |= P_WEXIT;
206 PROC_UNLOCK(p);
207
208 /* Are we a task leader? */
209 PROC_LOCK(p);
210 if (p == p->p_leader) {
211 q = p->p_peers;
212 while (q != NULL) {
213 PROC_LOCK(q);
214 psignal(q, SIGKILL);
215 PROC_UNLOCK(q);
216 q = q->p_peers;
217 }
218 while (p->p_peers)
219 msleep(p, &p->p_mtx, PWAIT, "exit1", 0);
220 }
221 PROC_UNLOCK(p);
222
223#ifdef PGINPROF
224 vmsizmon();
225#endif
226 STOPEVENT(p, S_EXIT, rv);
227 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */
228
229 /*
230 * Check if any loadable modules need anything done at process exit.
231 * e.g. SYSV IPC stuff
232 * XXX what if one of these generates an error?
233 */
234 TAILQ_FOREACH(ep, &exit_list, next)
235 (*ep->function)(p);
236
237 stopprofclock(p);
238
239 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
240 M_ZOMBIE, M_WAITOK);
241 /*
242 * If parent is waiting for us to exit or exec,
243 * P_PPWAIT is set; we will wakeup the parent below.
244 */
245 PROC_LOCK(p);
246 p->p_flag &= ~(P_TRACED | P_PPWAIT);
247 SIGEMPTYSET(p->p_siglist);
248 PROC_UNLOCK(p);
249 if (timevalisset(&p->p_realtimer.it_value))
250 callout_stop(&p->p_itcallout);
251
252 /*
253 * Reset any sigio structures pointing to us as a result of
254 * F_SETOWN with our pid.
255 */
256 funsetownlst(&p->p_sigiolst);
257
258 /*
259 * Close open files and release open-file table.
260 * This may block!
261 */
262 fdfree(td); /* XXXKSE *//* may not be the one in proc */
263
264 /*
265 * Remove ourself from our leader's peer list and wake our leader.
266 */
267 PROC_LOCK(p->p_leader);
268 if (p->p_leader->p_peers) {
269 q = p->p_leader;
270 while (q->p_peers != p)
271 q = q->p_peers;
272 q->p_peers = p->p_peers;
273 wakeup(p->p_leader);
274 }
275 PROC_UNLOCK(p->p_leader);
276
277 /* The next two chunks should probably be moved to vmspace_exit. */
278 vm = p->p_vmspace;
279 /*
280 * Release user portion of address space.
281 * This releases references to vnodes,
282 * which could cause I/O if the file has been unlinked.
283 * Need to do this early enough that we can still sleep.
284 * Can't free the entire vmspace as the kernel stack
285 * may be mapped within that space also.
286 */
287 if (--vm->vm_refcnt == 0) {
288 if (vm->vm_shm)
289 shmexit(p);
| 40 */
41
42#include "opt_compat.h"
43#include "opt_ktrace.h"
44
45#include <sys/param.h>
46#include <sys/systm.h>
47#include <sys/sysproto.h>
48#include <sys/kernel.h>
49#include <sys/malloc.h>
50#include <sys/lock.h>
51#include <sys/mutex.h>
52#include <sys/proc.h>
53#include <sys/pioctl.h>
54#include <sys/tty.h>
55#include <sys/wait.h>
56#include <sys/vmmeter.h>
57#include <sys/vnode.h>
58#include <sys/resourcevar.h>
59#include <sys/signalvar.h>
60#include <sys/sx.h>
61#include <sys/ptrace.h>
62#include <sys/acct.h> /* for acct_process() function prototype */
63#include <sys/filedesc.h>
64#include <sys/shm.h>
65#include <sys/sem.h>
66#include <sys/jail.h>
67#ifdef KTRACE
68#include <sys/ktrace.h>
69#endif
70
71#include <vm/vm.h>
72#include <vm/vm_extern.h>
73#include <vm/vm_param.h>
74#include <vm/pmap.h>
75#include <vm/vm_map.h>
76#include <vm/uma.h>
77#include <sys/user.h>
78
79/* Required to be non-static for SysVR4 emulator */
80MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status");
81
82static MALLOC_DEFINE(M_ATEXIT, "atexit", "atexit callback");
83
84static int wait1(struct thread *, struct wait_args *, int);
85
86/*
87 * callout list for things to do at exit time
88 */
89struct exitlist {
90 exitlist_fn function;
91 TAILQ_ENTRY(exitlist) next;
92};
93
94TAILQ_HEAD(exit_list_head, exitlist);
95static struct exit_list_head exit_list = TAILQ_HEAD_INITIALIZER(exit_list);
96
97/*
98 * exit --
99 * Death of process.
100 *
101 * MPSAFE
102 */
103void
104sys_exit(td, uap)
105 struct thread *td;
106 struct sys_exit_args /* {
107 int rval;
108 } */ *uap;
109{
110
111 mtx_lock(&Giant);
112 exit1(td, W_EXITCODE(uap->rval, 0));
113 /* NOTREACHED */
114}
115
116/*
117 * Exit: deallocate address space and other resources, change proc state
118 * to zombie, and unlink proc from allproc and parent's lists. Save exit
119 * status and rusage for wait(). Check for child processes and orphan them.
120 */
121void
122exit1(td, rv)
123 register struct thread *td;
124 int rv;
125{
126 struct exitlist *ep;
127 struct proc *p, *nq, *q;
128 struct tty *tp;
129 struct vnode *ttyvp;
130 register struct vmspace *vm;
131 struct vnode *vtmp;
132#ifdef KTRACE
133 struct vnode *tracevp;
134#endif
135
136 GIANT_REQUIRED;
137
138 p = td->td_proc;
139 if (p == initproc) {
140 printf("init died (signal %d, exit %d)\n",
141 WTERMSIG(rv), WEXITSTATUS(rv));
142 panic("Going nowhere without my init!");
143 }
144
145 /*
146 * XXXXKSE: MUST abort all other threads before proceeding past here.
147 */
148 PROC_LOCK(p);
149 if (p->p_flag & P_KSES) {
150 /*
151 * First check if some other thread got here before us..
152 * if so, act apropriatly, (exit or suspend);
153 */
154 thread_suspend_check(0);
155 /*
156 * Here is a trick..
157 * We need to free up our KSE to process other threads
158 * so that we can safely set the UNBOUND flag
159 * (whether or not we have a mailbox) as we are NEVER
160 * going to return to the user.
161 * The flag will not be set yet if we are exiting
162 * because of a signal, pagefault, or similar
163 * (or even an exit(2) from the UTS).
164 */
165 td->td_flags |= TDF_UNBOUND;
166
167 /*
168 * Kill off the other threads. This requires
169 * Some co-operation from other parts of the kernel
170 * so it may not be instant.
171 * With this state set:
172 * Any thread entering the kernel from userspace will
173 * thread_exit() in trap(). Any thread attempting to
174 * sleep will return immediatly
175 * with EINTR or EWOULDBLOCK, which will hopefully force them
176 * to back out to userland, freeing resources as they go, and
177 * anything attempting to return to userland will thread_exit()
178 * from userret(). thread_exit() will unsuspend us
179 * when the last other thread exits.
180 */
181 if (thread_single(SINGLE_EXIT)) {
182 panic ("Exit: Single threading fouled up");
183 }
184 /*
185 * All other activity in this process is now stopped.
186 * Remove excess KSEs and KSEGRPS. XXXKSE (when we have them)
187 * ...
188 * Turn off threading support.
189 */
190 p->p_flag &= ~P_KSES;
191 td->td_flags &= ~TDF_UNBOUND;
192 thread_single_end(); /* Don't need this any more. */
193 }
194 /*
195 * With this state set:
196 * Any thread entering the kernel from userspace will thread_exit()
197 * in trap(). Any thread attempting to sleep will return immediatly
198 * with EINTR or EWOULDBLOCK, which will hopefully force them
199 * to back out to userland, freeing resources as they go, and
200 * anything attempting to return to userland will thread_exit()
201 * from userret(). thread_exit() will do a wakeup on p->p_numthreads
202 * if it transitions to 1.
203 */
204
205 p->p_flag |= P_WEXIT;
206 PROC_UNLOCK(p);
207
208 /* Are we a task leader? */
209 PROC_LOCK(p);
210 if (p == p->p_leader) {
211 q = p->p_peers;
212 while (q != NULL) {
213 PROC_LOCK(q);
214 psignal(q, SIGKILL);
215 PROC_UNLOCK(q);
216 q = q->p_peers;
217 }
218 while (p->p_peers)
219 msleep(p, &p->p_mtx, PWAIT, "exit1", 0);
220 }
221 PROC_UNLOCK(p);
222
223#ifdef PGINPROF
224 vmsizmon();
225#endif
226 STOPEVENT(p, S_EXIT, rv);
227 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */
228
229 /*
230 * Check if any loadable modules need anything done at process exit.
231 * e.g. SYSV IPC stuff
232 * XXX what if one of these generates an error?
233 */
234 TAILQ_FOREACH(ep, &exit_list, next)
235 (*ep->function)(p);
236
237 stopprofclock(p);
238
239 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
240 M_ZOMBIE, M_WAITOK);
241 /*
242 * If parent is waiting for us to exit or exec,
243 * P_PPWAIT is set; we will wakeup the parent below.
244 */
245 PROC_LOCK(p);
246 p->p_flag &= ~(P_TRACED | P_PPWAIT);
247 SIGEMPTYSET(p->p_siglist);
248 PROC_UNLOCK(p);
249 if (timevalisset(&p->p_realtimer.it_value))
250 callout_stop(&p->p_itcallout);
251
252 /*
253 * Reset any sigio structures pointing to us as a result of
254 * F_SETOWN with our pid.
255 */
256 funsetownlst(&p->p_sigiolst);
257
258 /*
259 * Close open files and release open-file table.
260 * This may block!
261 */
262 fdfree(td); /* XXXKSE *//* may not be the one in proc */
263
264 /*
265 * Remove ourself from our leader's peer list and wake our leader.
266 */
267 PROC_LOCK(p->p_leader);
268 if (p->p_leader->p_peers) {
269 q = p->p_leader;
270 while (q->p_peers != p)
271 q = q->p_peers;
272 q->p_peers = p->p_peers;
273 wakeup(p->p_leader);
274 }
275 PROC_UNLOCK(p->p_leader);
276
277 /* The next two chunks should probably be moved to vmspace_exit. */
278 vm = p->p_vmspace;
279 /*
280 * Release user portion of address space.
281 * This releases references to vnodes,
282 * which could cause I/O if the file has been unlinked.
283 * Need to do this early enough that we can still sleep.
284 * Can't free the entire vmspace as the kernel stack
285 * may be mapped within that space also.
286 */
287 if (--vm->vm_refcnt == 0) {
288 if (vm->vm_shm)
289 shmexit(p);
|
294 vm->vm_freer = p;
295 }
296
297 sx_xlock(&proctree_lock);
298 if (SESS_LEADER(p)) {
299 register struct session *sp;
300
301 sp = p->p_session;
302 if (sp->s_ttyvp) {
303 /*
304 * Controlling process.
305 * Signal foreground pgrp,
306 * drain controlling terminal
307 * and revoke access to controlling terminal.
308 */
309 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) {
310 tp = sp->s_ttyp;
311 if (sp->s_ttyp->t_pgrp) {
312 PGRP_LOCK(sp->s_ttyp->t_pgrp);
313 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
314 PGRP_UNLOCK(sp->s_ttyp->t_pgrp);
315 }
316 /* XXX tp should be locked. */
317 sx_xunlock(&proctree_lock);
318 (void) ttywait(tp);
319 sx_xlock(&proctree_lock);
320 /*
321 * The tty could have been revoked
322 * if we blocked.
323 */
324 if (sp->s_ttyvp) {
325 ttyvp = sp->s_ttyvp;
326 SESS_LOCK(p->p_session);
327 sp->s_ttyvp = NULL;
328 SESS_UNLOCK(p->p_session);
329 sx_xunlock(&proctree_lock);
330 VOP_REVOKE(ttyvp, REVOKEALL);
331 vrele(ttyvp);
332 sx_xlock(&proctree_lock);
333 }
334 }
335 if (sp->s_ttyvp) {
336 ttyvp = sp->s_ttyvp;
337 SESS_LOCK(p->p_session);
338 sp->s_ttyvp = NULL;
339 SESS_UNLOCK(p->p_session);
340 vrele(ttyvp);
341 }
342 /*
343 * s_ttyp is not zero'd; we use this to indicate
344 * that the session once had a controlling terminal.
345 * (for logging and informational purposes)
346 */
347 }
348 SESS_LOCK(p->p_session);
349 sp->s_leader = NULL;
350 SESS_UNLOCK(p->p_session);
351 }
352 fixjobc(p, p->p_pgrp, 0);
353 sx_xunlock(&proctree_lock);
354 (void)acct_process(td);
355#ifdef KTRACE
356 /*
357 * release trace file
358 */
359 PROC_LOCK(p);
360 mtx_lock(&ktrace_mtx);
361 p->p_traceflag = 0; /* don't trace the vrele() */
362 tracevp = p->p_tracep;
363 p->p_tracep = NULL;
364 mtx_unlock(&ktrace_mtx);
365 PROC_UNLOCK(p);
366 if (tracevp != NULL)
367 vrele(tracevp);
368#endif
369 /*
370 * Release reference to text vnode
371 */
372 if ((vtmp = p->p_textvp) != NULL) {
373 p->p_textvp = NULL;
374 vrele(vtmp);
375 }
376
377 /*
378 * Release our limits structure.
379 */
380 mtx_assert(&Giant, MA_OWNED);
381 if (--p->p_limit->p_refcnt == 0) {
382 FREE(p->p_limit, M_SUBPROC);
383 p->p_limit = NULL;
384 }
385
386 /*
387 * Release this thread's reference to the ucred. The actual proc
388 * reference will stay around until the proc is harvested by
389 * wait(). At this point the ucred is immutable (no other threads
390 * from this proc are around that can change it) so we leave the
391 * per-thread ucred pointer intact in case it is needed although
392 * in theory nothing should be using it at this point.
393 */
394 crfree(td->td_ucred);
395
396 /*
397 * Remove proc from allproc queue and pidhash chain.
398 * Place onto zombproc. Unlink from parent's child list.
399 */
400 sx_xlock(&allproc_lock);
401 LIST_REMOVE(p, p_list);
402 LIST_INSERT_HEAD(&zombproc, p, p_list);
403 LIST_REMOVE(p, p_hash);
404 sx_xunlock(&allproc_lock);
405
406 sx_xlock(&proctree_lock);
407 q = LIST_FIRST(&p->p_children);
408 if (q != NULL) /* only need this if any child is S_ZOMB */
409 wakeup(initproc);
410 for (; q != NULL; q = nq) {
411 nq = LIST_NEXT(q, p_sibling);
412 PROC_LOCK(q);
413 proc_reparent(q, initproc);
414 q->p_sigparent = SIGCHLD;
415 /*
416 * Traced processes are killed
417 * since their existence means someone is screwing up.
418 */
419 if (q->p_flag & P_TRACED) {
420 q->p_flag &= ~P_TRACED;
421 psignal(q, SIGKILL);
422 }
423 PROC_UNLOCK(q);
424 }
425
426 /*
427 * Save exit status and final rusage info, adding in child rusage
428 * info and self times.
429 */
430 PROC_LOCK(p);
431 p->p_xstat = rv;
432 *p->p_ru = p->p_stats->p_ru;
433 mtx_lock_spin(&sched_lock);
434 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL);
435 mtx_unlock_spin(&sched_lock);
436 ruadd(p->p_ru, &p->p_stats->p_cru);
437
438 /*
439 * Notify interested parties of our demise.
440 */
441 KNOTE(&p->p_klist, NOTE_EXIT);
442
443 /*
444 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT
445 * flag set, or if the handler is set to SIG_IGN, notify process
446 * 1 instead (and hope it will handle this situation).
447 */
448 PROC_LOCK(p->p_pptr);
449 if (p->p_pptr->p_procsig->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
450 struct proc *pp;
451
452 pp = p->p_pptr;
453 PROC_UNLOCK(pp);
454 proc_reparent(p, initproc);
455 PROC_LOCK(p->p_pptr);
456 /*
457 * If this was the last child of our parent, notify
458 * parent, so in case he was wait(2)ing, he will
459 * continue.
460 */
461 if (LIST_EMPTY(&pp->p_children))
462 wakeup(pp);
463 }
464
465 if (p->p_sigparent && p->p_pptr != initproc)
466 psignal(p->p_pptr, p->p_sigparent);
467 else
468 psignal(p->p_pptr, SIGCHLD);
469 PROC_UNLOCK(p->p_pptr);
470
471 /*
472 * If this is a kthread, then wakeup anyone waiting for it to exit.
473 */
474 if (p->p_flag & P_KTHREAD)
475 wakeup(p);
476 PROC_UNLOCK(p);
477
478 /*
479 * Finally, call machine-dependent code to release the remaining
480 * resources including address space, the kernel stack and pcb.
481 * The address space is released by "vmspace_exitfree(p)" in
482 * vm_waitproc().
483 */
484 cpu_exit(td);
485
486 PROC_LOCK(p);
487 PROC_LOCK(p->p_pptr);
488 sx_xunlock(&proctree_lock);
489 mtx_lock_spin(&sched_lock);
490 while (mtx_owned(&Giant))
491 mtx_unlock(&Giant);
492
493 /*
494 * We have to wait until after releasing all locks before
495 * changing p_state. If we block on a mutex then we will be
496 * back at SRUN when we resume and our parent will never
497 * harvest us.
498 */
499 p->p_state = PRS_ZOMBIE;
500
501 wakeup(p->p_pptr);
502 PROC_UNLOCK(p->p_pptr);
503 cnt.v_swtch++;
504 binuptime(PCPU_PTR(switchtime));
505 PCPU_SET(switchticks, ticks);
506
507 cpu_sched_exit(td); /* XXXKSE check if this should be in thread_exit */
508 /*
509 * Make sure this thread is discarded from the zombie.
510 * This will also release this thread's reference to the ucred.
511 */
512 thread_exit();
513 panic("exit1");
514}
515
516#ifdef COMPAT_43
517/*
518 * MPSAFE. The dirty work is handled by wait1().
519 */
520int
521owait(td, uap)
522 struct thread *td;
523 register struct owait_args /* {
524 int dummy;
525 } */ *uap;
526{
527 struct wait_args w;
528
529 w.options = 0;
530 w.rusage = NULL;
531 w.pid = WAIT_ANY;
532 w.status = NULL;
533 return (wait1(td, &w, 1));
534}
535#endif /* COMPAT_43 */
536
537/*
538 * MPSAFE. The dirty work is handled by wait1().
539 */
540int
541wait4(td, uap)
542 struct thread *td;
543 struct wait_args *uap;
544{
545
546 return (wait1(td, uap, 0));
547}
548
549/*
550 * MPSAFE
551 */
552static int
553wait1(td, uap, compat)
554 register struct thread *td;
555 register struct wait_args /* {
556 int pid;
557 int *status;
558 int options;
559 struct rusage *rusage;
560 } */ *uap;
561 int compat;
562{
563 struct rusage ru;
564 register int nfound;
565 register struct proc *p, *q, *t;
566 int status, error;
567 struct kse *ke;
568 struct ksegrp *kg;
569
570 q = td->td_proc;
571 if (uap->pid == 0) {
572 PROC_LOCK(q);
573 uap->pid = -q->p_pgid;
574 PROC_UNLOCK(q);
575 }
576 if (uap->options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE))
577 return (EINVAL);
578 mtx_lock(&Giant);
579loop:
580 nfound = 0;
581 sx_xlock(&proctree_lock);
582 LIST_FOREACH(p, &q->p_children, p_sibling) {
583 PROC_LOCK(p);
584 if (uap->pid != WAIT_ANY &&
585 p->p_pid != uap->pid && p->p_pgid != -uap->pid) {
586 PROC_UNLOCK(p);
587 continue;
588 }
589
590 /*
591 * This special case handles a kthread spawned by linux_clone
592 * (see linux_misc.c). The linux_wait4 and linux_waitpid
593 * functions need to be able to distinguish between waiting
594 * on a process and waiting on a thread. It is a thread if
595 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
596 * signifies we want to wait for threads and not processes.
597 */
598 if ((p->p_sigparent != SIGCHLD) ^
599 ((uap->options & WLINUXCLONE) != 0)) {
600 PROC_UNLOCK(p);
601 continue;
602 }
603
604 nfound++;
605 if (p->p_state == PRS_ZOMBIE) {
606 /*
607 * charge childs scheduling cpu usage to parent
608 * XXXKSE assume only one thread & kse & ksegrp
609 * keep estcpu in each ksegrp
610 * so charge it to the ksegrp that did the wait
611 * since process estcpu is sum of all ksegrps,
612 * this is strictly as expected.
613 * Assume that the child process aggregated all
614 * tke estcpu into the 'build-in' ksegrp.
615 * XXXKSE
616 */
617 if (curthread->td_proc->p_pid != 1) {
618 mtx_lock_spin(&sched_lock);
619 curthread->td_ksegrp->kg_estcpu =
620 ESTCPULIM(curthread->td_ksegrp->kg_estcpu +
621 FIRST_KSEGRP_IN_PROC(p)->kg_estcpu);
622 mtx_unlock_spin(&sched_lock);
623 }
624
625 td->td_retval[0] = p->p_pid;
626#ifdef COMPAT_43
627 if (compat)
628 td->td_retval[1] = p->p_xstat;
629 else
630#endif
631 if (uap->status) {
632 status = p->p_xstat; /* convert to int */
633 PROC_UNLOCK(p);
634 if ((error = copyout(&status,
635 uap->status, sizeof(status)))) {
636 sx_xunlock(&proctree_lock);
637 mtx_unlock(&Giant);
638 return (error);
639 }
640 PROC_LOCK(p);
641 }
642 if (uap->rusage) {
643 bcopy(p->p_ru, &ru, sizeof(ru));
644 PROC_UNLOCK(p);
645 if ((error = copyout(&ru,
646 uap->rusage, sizeof (struct rusage)))) {
647 sx_xunlock(&proctree_lock);
648 mtx_unlock(&Giant);
649 return (error);
650 }
651 } else
652 PROC_UNLOCK(p);
653 /*
654 * If we got the child via a ptrace 'attach',
655 * we need to give it back to the old parent.
656 */
657 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) {
658 PROC_LOCK(p);
659 p->p_oppid = 0;
660 proc_reparent(p, t);
661 PROC_UNLOCK(p);
662 psignal(t, SIGCHLD);
663 wakeup(t);
664 PROC_UNLOCK(t);
665 sx_xunlock(&proctree_lock);
666 mtx_unlock(&Giant);
667 return (0);
668 }
669 /*
670 * Remove other references to this process to ensure
671 * we have an exclusive reference.
672 */
673 leavepgrp(p);
674
675 sx_xlock(&allproc_lock);
676 LIST_REMOVE(p, p_list); /* off zombproc */
677 sx_xunlock(&allproc_lock);
678
679 LIST_REMOVE(p, p_sibling);
680 sx_xunlock(&proctree_lock);
681
682 /*
683 * As a side effect of this lock, we know that
684 * all other writes to this proc are visible now, so
685 * no more locking is needed for p.
686 */
687 PROC_LOCK(p);
688 p->p_xstat = 0; /* XXX: why? */
689 PROC_UNLOCK(p);
690 PROC_LOCK(q);
691 ruadd(&q->p_stats->p_cru, p->p_ru);
692 PROC_UNLOCK(q);
693 FREE(p->p_ru, M_ZOMBIE);
694 p->p_ru = NULL;
695
696 /*
697 * Decrement the count of procs running with this uid.
698 */
699 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
700
701 /*
702 * Free up credentials.
703 */
704 crfree(p->p_ucred);
705 p->p_ucred = NULL; /* XXX: why? */
706
707 /*
708 * Remove unused arguments
709 */
710 pargs_drop(p->p_args);
711 p->p_args = NULL;
712
713 if (--p->p_procsig->ps_refcnt == 0) {
714 if (p->p_sigacts != &p->p_uarea->u_sigacts)
715 FREE(p->p_sigacts, M_SUBPROC);
716 FREE(p->p_procsig, M_SUBPROC);
717 p->p_procsig = NULL;
718 }
719
720 /*
721 * There should only be one KSE/KSEGRP but
722 * do it right anyhow.
723 */
724 FOREACH_KSEGRP_IN_PROC(p, kg) {
725 FOREACH_KSE_IN_GROUP(kg, ke) {
726 /* Free the KSE spare thread. */
727 if (ke->ke_tdspare != NULL) {
728 thread_free(ke->ke_tdspare);
729 ke->ke_tdspare = NULL;
730 }
731 }
732 }
733 thread_reap(); /* check for zombie threads */
734
735 /*
736 * Give vm and machine-dependent layer a chance
737 * to free anything that cpu_exit couldn't
738 * release while still running in process context.
739 */
740 vm_waitproc(p);
741 mtx_destroy(&p->p_mtx);
742 KASSERT(FIRST_THREAD_IN_PROC(p),
743 ("wait1: no residual thread!"));
744 uma_zfree(proc_zone, p);
745 sx_xlock(&allproc_lock);
746 nprocs--;
747 sx_xunlock(&allproc_lock);
748 mtx_unlock(&Giant);
749 return (0);
750 }
751 if (P_SHOULDSTOP(p) && ((p->p_flag & P_WAITED) == 0) &&
752 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) {
753 p->p_flag |= P_WAITED;
754 sx_xunlock(&proctree_lock);
755 td->td_retval[0] = p->p_pid;
756#ifdef COMPAT_43
757 if (compat) {
758 td->td_retval[1] = W_STOPCODE(p->p_xstat);
759 PROC_UNLOCK(p);
760 error = 0;
761 } else
762#endif
763 if (uap->status) {
764 status = W_STOPCODE(p->p_xstat);
765 PROC_UNLOCK(p);
766 error = copyout(&status,
767 uap->status, sizeof(status));
768 } else {
769 PROC_UNLOCK(p);
770 error = 0;
771 }
772 mtx_unlock(&Giant);
773 return (error);
774 }
775 if (uap->options & WCONTINUED && (p->p_flag & P_CONTINUED)) {
776 sx_xunlock(&proctree_lock);
777 td->td_retval[0] = p->p_pid;
778 p->p_flag &= ~P_CONTINUED;
779 PROC_UNLOCK(p);
780
781 if (uap->status) {
782 status = SIGCONT;
783 error = copyout(&status,
784 uap->status, sizeof(status));
785 } else
786 error = 0;
787
788 mtx_unlock(&Giant);
789 return (error);
790 }
791 PROC_UNLOCK(p);
792 }
793 if (nfound == 0) {
794 sx_xunlock(&proctree_lock);
795 mtx_unlock(&Giant);
796 return (ECHILD);
797 }
798 if (uap->options & WNOHANG) {
799 sx_xunlock(&proctree_lock);
800 td->td_retval[0] = 0;
801 mtx_unlock(&Giant);
802 return (0);
803 }
804 PROC_LOCK(q);
805 sx_xunlock(&proctree_lock);
806 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0);
807 PROC_UNLOCK(q);
808 if (error) {
809 mtx_unlock(&Giant);
810 return (error);
811 }
812 goto loop;
813}
814
815/*
816 * Make process 'parent' the new parent of process 'child'.
817 * Must be called with an exclusive hold of proctree lock.
818 */
819void
820proc_reparent(child, parent)
821 register struct proc *child;
822 register struct proc *parent;
823{
824
825 sx_assert(&proctree_lock, SX_XLOCKED);
826 PROC_LOCK_ASSERT(child, MA_OWNED);
827 if (child->p_pptr == parent)
828 return;
829
830 LIST_REMOVE(child, p_sibling);
831 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
832 child->p_pptr = parent;
833}
834
835/*
836 * The next two functions are to handle adding/deleting items on the
837 * exit callout list
838 *
839 * at_exit():
840 * Take the arguments given and put them onto the exit callout list,
841 * However first make sure that it's not already there.
842 * returns 0 on success.
843 */
844
845int
846at_exit(function)
847 exitlist_fn function;
848{
849 struct exitlist *ep;
850
851#ifdef INVARIANTS
852 /* Be noisy if the programmer has lost track of things */
853 if (rm_at_exit(function))
854 printf("WARNING: exit callout entry (%p) already present\n",
855 function);
856#endif
857 ep = malloc(sizeof(*ep), M_ATEXIT, M_NOWAIT);
858 if (ep == NULL)
859 return (ENOMEM);
860 ep->function = function;
861 TAILQ_INSERT_TAIL(&exit_list, ep, next);
862 return (0);
863}
864
865/*
866 * Scan the exit callout list for the given item and remove it.
867 * Returns the number of items removed (0 or 1)
868 */
869int
870rm_at_exit(function)
871 exitlist_fn function;
872{
873 struct exitlist *ep;
874
875 TAILQ_FOREACH(ep, &exit_list, next) {
876 if (ep->function == function) {
877 TAILQ_REMOVE(&exit_list, ep, next);
878 free(ep, M_ATEXIT);
879 return (1);
880 }
881 }
882 return (0);
883}
| 294 vm->vm_freer = p;
295 }
296
297 sx_xlock(&proctree_lock);
298 if (SESS_LEADER(p)) {
299 register struct session *sp;
300
301 sp = p->p_session;
302 if (sp->s_ttyvp) {
303 /*
304 * Controlling process.
305 * Signal foreground pgrp,
306 * drain controlling terminal
307 * and revoke access to controlling terminal.
308 */
309 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) {
310 tp = sp->s_ttyp;
311 if (sp->s_ttyp->t_pgrp) {
312 PGRP_LOCK(sp->s_ttyp->t_pgrp);
313 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
314 PGRP_UNLOCK(sp->s_ttyp->t_pgrp);
315 }
316 /* XXX tp should be locked. */
317 sx_xunlock(&proctree_lock);
318 (void) ttywait(tp);
319 sx_xlock(&proctree_lock);
320 /*
321 * The tty could have been revoked
322 * if we blocked.
323 */
324 if (sp->s_ttyvp) {
325 ttyvp = sp->s_ttyvp;
326 SESS_LOCK(p->p_session);
327 sp->s_ttyvp = NULL;
328 SESS_UNLOCK(p->p_session);
329 sx_xunlock(&proctree_lock);
330 VOP_REVOKE(ttyvp, REVOKEALL);
331 vrele(ttyvp);
332 sx_xlock(&proctree_lock);
333 }
334 }
335 if (sp->s_ttyvp) {
336 ttyvp = sp->s_ttyvp;
337 SESS_LOCK(p->p_session);
338 sp->s_ttyvp = NULL;
339 SESS_UNLOCK(p->p_session);
340 vrele(ttyvp);
341 }
342 /*
343 * s_ttyp is not zero'd; we use this to indicate
344 * that the session once had a controlling terminal.
345 * (for logging and informational purposes)
346 */
347 }
348 SESS_LOCK(p->p_session);
349 sp->s_leader = NULL;
350 SESS_UNLOCK(p->p_session);
351 }
352 fixjobc(p, p->p_pgrp, 0);
353 sx_xunlock(&proctree_lock);
354 (void)acct_process(td);
355#ifdef KTRACE
356 /*
357 * release trace file
358 */
359 PROC_LOCK(p);
360 mtx_lock(&ktrace_mtx);
361 p->p_traceflag = 0; /* don't trace the vrele() */
362 tracevp = p->p_tracep;
363 p->p_tracep = NULL;
364 mtx_unlock(&ktrace_mtx);
365 PROC_UNLOCK(p);
366 if (tracevp != NULL)
367 vrele(tracevp);
368#endif
369 /*
370 * Release reference to text vnode
371 */
372 if ((vtmp = p->p_textvp) != NULL) {
373 p->p_textvp = NULL;
374 vrele(vtmp);
375 }
376
377 /*
378 * Release our limits structure.
379 */
380 mtx_assert(&Giant, MA_OWNED);
381 if (--p->p_limit->p_refcnt == 0) {
382 FREE(p->p_limit, M_SUBPROC);
383 p->p_limit = NULL;
384 }
385
386 /*
387 * Release this thread's reference to the ucred. The actual proc
388 * reference will stay around until the proc is harvested by
389 * wait(). At this point the ucred is immutable (no other threads
390 * from this proc are around that can change it) so we leave the
391 * per-thread ucred pointer intact in case it is needed although
392 * in theory nothing should be using it at this point.
393 */
394 crfree(td->td_ucred);
395
396 /*
397 * Remove proc from allproc queue and pidhash chain.
398 * Place onto zombproc. Unlink from parent's child list.
399 */
400 sx_xlock(&allproc_lock);
401 LIST_REMOVE(p, p_list);
402 LIST_INSERT_HEAD(&zombproc, p, p_list);
403 LIST_REMOVE(p, p_hash);
404 sx_xunlock(&allproc_lock);
405
406 sx_xlock(&proctree_lock);
407 q = LIST_FIRST(&p->p_children);
408 if (q != NULL) /* only need this if any child is S_ZOMB */
409 wakeup(initproc);
410 for (; q != NULL; q = nq) {
411 nq = LIST_NEXT(q, p_sibling);
412 PROC_LOCK(q);
413 proc_reparent(q, initproc);
414 q->p_sigparent = SIGCHLD;
415 /*
416 * Traced processes are killed
417 * since their existence means someone is screwing up.
418 */
419 if (q->p_flag & P_TRACED) {
420 q->p_flag &= ~P_TRACED;
421 psignal(q, SIGKILL);
422 }
423 PROC_UNLOCK(q);
424 }
425
426 /*
427 * Save exit status and final rusage info, adding in child rusage
428 * info and self times.
429 */
430 PROC_LOCK(p);
431 p->p_xstat = rv;
432 *p->p_ru = p->p_stats->p_ru;
433 mtx_lock_spin(&sched_lock);
434 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL);
435 mtx_unlock_spin(&sched_lock);
436 ruadd(p->p_ru, &p->p_stats->p_cru);
437
438 /*
439 * Notify interested parties of our demise.
440 */
441 KNOTE(&p->p_klist, NOTE_EXIT);
442
443 /*
444 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT
445 * flag set, or if the handler is set to SIG_IGN, notify process
446 * 1 instead (and hope it will handle this situation).
447 */
448 PROC_LOCK(p->p_pptr);
449 if (p->p_pptr->p_procsig->ps_flag & (PS_NOCLDWAIT | PS_CLDSIGIGN)) {
450 struct proc *pp;
451
452 pp = p->p_pptr;
453 PROC_UNLOCK(pp);
454 proc_reparent(p, initproc);
455 PROC_LOCK(p->p_pptr);
456 /*
457 * If this was the last child of our parent, notify
458 * parent, so in case he was wait(2)ing, he will
459 * continue.
460 */
461 if (LIST_EMPTY(&pp->p_children))
462 wakeup(pp);
463 }
464
465 if (p->p_sigparent && p->p_pptr != initproc)
466 psignal(p->p_pptr, p->p_sigparent);
467 else
468 psignal(p->p_pptr, SIGCHLD);
469 PROC_UNLOCK(p->p_pptr);
470
471 /*
472 * If this is a kthread, then wakeup anyone waiting for it to exit.
473 */
474 if (p->p_flag & P_KTHREAD)
475 wakeup(p);
476 PROC_UNLOCK(p);
477
478 /*
479 * Finally, call machine-dependent code to release the remaining
480 * resources including address space, the kernel stack and pcb.
481 * The address space is released by "vmspace_exitfree(p)" in
482 * vm_waitproc().
483 */
484 cpu_exit(td);
485
486 PROC_LOCK(p);
487 PROC_LOCK(p->p_pptr);
488 sx_xunlock(&proctree_lock);
489 mtx_lock_spin(&sched_lock);
490 while (mtx_owned(&Giant))
491 mtx_unlock(&Giant);
492
493 /*
494 * We have to wait until after releasing all locks before
495 * changing p_state. If we block on a mutex then we will be
496 * back at SRUN when we resume and our parent will never
497 * harvest us.
498 */
499 p->p_state = PRS_ZOMBIE;
500
501 wakeup(p->p_pptr);
502 PROC_UNLOCK(p->p_pptr);
503 cnt.v_swtch++;
504 binuptime(PCPU_PTR(switchtime));
505 PCPU_SET(switchticks, ticks);
506
507 cpu_sched_exit(td); /* XXXKSE check if this should be in thread_exit */
508 /*
509 * Make sure this thread is discarded from the zombie.
510 * This will also release this thread's reference to the ucred.
511 */
512 thread_exit();
513 panic("exit1");
514}
515
516#ifdef COMPAT_43
517/*
518 * MPSAFE. The dirty work is handled by wait1().
519 */
520int
521owait(td, uap)
522 struct thread *td;
523 register struct owait_args /* {
524 int dummy;
525 } */ *uap;
526{
527 struct wait_args w;
528
529 w.options = 0;
530 w.rusage = NULL;
531 w.pid = WAIT_ANY;
532 w.status = NULL;
533 return (wait1(td, &w, 1));
534}
535#endif /* COMPAT_43 */
536
537/*
538 * MPSAFE. The dirty work is handled by wait1().
539 */
540int
541wait4(td, uap)
542 struct thread *td;
543 struct wait_args *uap;
544{
545
546 return (wait1(td, uap, 0));
547}
548
549/*
550 * MPSAFE
551 */
552static int
553wait1(td, uap, compat)
554 register struct thread *td;
555 register struct wait_args /* {
556 int pid;
557 int *status;
558 int options;
559 struct rusage *rusage;
560 } */ *uap;
561 int compat;
562{
563 struct rusage ru;
564 register int nfound;
565 register struct proc *p, *q, *t;
566 int status, error;
567 struct kse *ke;
568 struct ksegrp *kg;
569
570 q = td->td_proc;
571 if (uap->pid == 0) {
572 PROC_LOCK(q);
573 uap->pid = -q->p_pgid;
574 PROC_UNLOCK(q);
575 }
576 if (uap->options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE))
577 return (EINVAL);
578 mtx_lock(&Giant);
579loop:
580 nfound = 0;
581 sx_xlock(&proctree_lock);
582 LIST_FOREACH(p, &q->p_children, p_sibling) {
583 PROC_LOCK(p);
584 if (uap->pid != WAIT_ANY &&
585 p->p_pid != uap->pid && p->p_pgid != -uap->pid) {
586 PROC_UNLOCK(p);
587 continue;
588 }
589
590 /*
591 * This special case handles a kthread spawned by linux_clone
592 * (see linux_misc.c). The linux_wait4 and linux_waitpid
593 * functions need to be able to distinguish between waiting
594 * on a process and waiting on a thread. It is a thread if
595 * p_sigparent is not SIGCHLD, and the WLINUXCLONE option
596 * signifies we want to wait for threads and not processes.
597 */
598 if ((p->p_sigparent != SIGCHLD) ^
599 ((uap->options & WLINUXCLONE) != 0)) {
600 PROC_UNLOCK(p);
601 continue;
602 }
603
604 nfound++;
605 if (p->p_state == PRS_ZOMBIE) {
606 /*
607 * charge childs scheduling cpu usage to parent
608 * XXXKSE assume only one thread & kse & ksegrp
609 * keep estcpu in each ksegrp
610 * so charge it to the ksegrp that did the wait
611 * since process estcpu is sum of all ksegrps,
612 * this is strictly as expected.
613 * Assume that the child process aggregated all
614 * tke estcpu into the 'build-in' ksegrp.
615 * XXXKSE
616 */
617 if (curthread->td_proc->p_pid != 1) {
618 mtx_lock_spin(&sched_lock);
619 curthread->td_ksegrp->kg_estcpu =
620 ESTCPULIM(curthread->td_ksegrp->kg_estcpu +
621 FIRST_KSEGRP_IN_PROC(p)->kg_estcpu);
622 mtx_unlock_spin(&sched_lock);
623 }
624
625 td->td_retval[0] = p->p_pid;
626#ifdef COMPAT_43
627 if (compat)
628 td->td_retval[1] = p->p_xstat;
629 else
630#endif
631 if (uap->status) {
632 status = p->p_xstat; /* convert to int */
633 PROC_UNLOCK(p);
634 if ((error = copyout(&status,
635 uap->status, sizeof(status)))) {
636 sx_xunlock(&proctree_lock);
637 mtx_unlock(&Giant);
638 return (error);
639 }
640 PROC_LOCK(p);
641 }
642 if (uap->rusage) {
643 bcopy(p->p_ru, &ru, sizeof(ru));
644 PROC_UNLOCK(p);
645 if ((error = copyout(&ru,
646 uap->rusage, sizeof (struct rusage)))) {
647 sx_xunlock(&proctree_lock);
648 mtx_unlock(&Giant);
649 return (error);
650 }
651 } else
652 PROC_UNLOCK(p);
653 /*
654 * If we got the child via a ptrace 'attach',
655 * we need to give it back to the old parent.
656 */
657 if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) {
658 PROC_LOCK(p);
659 p->p_oppid = 0;
660 proc_reparent(p, t);
661 PROC_UNLOCK(p);
662 psignal(t, SIGCHLD);
663 wakeup(t);
664 PROC_UNLOCK(t);
665 sx_xunlock(&proctree_lock);
666 mtx_unlock(&Giant);
667 return (0);
668 }
669 /*
670 * Remove other references to this process to ensure
671 * we have an exclusive reference.
672 */
673 leavepgrp(p);
674
675 sx_xlock(&allproc_lock);
676 LIST_REMOVE(p, p_list); /* off zombproc */
677 sx_xunlock(&allproc_lock);
678
679 LIST_REMOVE(p, p_sibling);
680 sx_xunlock(&proctree_lock);
681
682 /*
683 * As a side effect of this lock, we know that
684 * all other writes to this proc are visible now, so
685 * no more locking is needed for p.
686 */
687 PROC_LOCK(p);
688 p->p_xstat = 0; /* XXX: why? */
689 PROC_UNLOCK(p);
690 PROC_LOCK(q);
691 ruadd(&q->p_stats->p_cru, p->p_ru);
692 PROC_UNLOCK(q);
693 FREE(p->p_ru, M_ZOMBIE);
694 p->p_ru = NULL;
695
696 /*
697 * Decrement the count of procs running with this uid.
698 */
699 (void)chgproccnt(p->p_ucred->cr_ruidinfo, -1, 0);
700
701 /*
702 * Free up credentials.
703 */
704 crfree(p->p_ucred);
705 p->p_ucred = NULL; /* XXX: why? */
706
707 /*
708 * Remove unused arguments
709 */
710 pargs_drop(p->p_args);
711 p->p_args = NULL;
712
713 if (--p->p_procsig->ps_refcnt == 0) {
714 if (p->p_sigacts != &p->p_uarea->u_sigacts)
715 FREE(p->p_sigacts, M_SUBPROC);
716 FREE(p->p_procsig, M_SUBPROC);
717 p->p_procsig = NULL;
718 }
719
720 /*
721 * There should only be one KSE/KSEGRP but
722 * do it right anyhow.
723 */
724 FOREACH_KSEGRP_IN_PROC(p, kg) {
725 FOREACH_KSE_IN_GROUP(kg, ke) {
726 /* Free the KSE spare thread. */
727 if (ke->ke_tdspare != NULL) {
728 thread_free(ke->ke_tdspare);
729 ke->ke_tdspare = NULL;
730 }
731 }
732 }
733 thread_reap(); /* check for zombie threads */
734
735 /*
736 * Give vm and machine-dependent layer a chance
737 * to free anything that cpu_exit couldn't
738 * release while still running in process context.
739 */
740 vm_waitproc(p);
741 mtx_destroy(&p->p_mtx);
742 KASSERT(FIRST_THREAD_IN_PROC(p),
743 ("wait1: no residual thread!"));
744 uma_zfree(proc_zone, p);
745 sx_xlock(&allproc_lock);
746 nprocs--;
747 sx_xunlock(&allproc_lock);
748 mtx_unlock(&Giant);
749 return (0);
750 }
751 if (P_SHOULDSTOP(p) && ((p->p_flag & P_WAITED) == 0) &&
752 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) {
753 p->p_flag |= P_WAITED;
754 sx_xunlock(&proctree_lock);
755 td->td_retval[0] = p->p_pid;
756#ifdef COMPAT_43
757 if (compat) {
758 td->td_retval[1] = W_STOPCODE(p->p_xstat);
759 PROC_UNLOCK(p);
760 error = 0;
761 } else
762#endif
763 if (uap->status) {
764 status = W_STOPCODE(p->p_xstat);
765 PROC_UNLOCK(p);
766 error = copyout(&status,
767 uap->status, sizeof(status));
768 } else {
769 PROC_UNLOCK(p);
770 error = 0;
771 }
772 mtx_unlock(&Giant);
773 return (error);
774 }
775 if (uap->options & WCONTINUED && (p->p_flag & P_CONTINUED)) {
776 sx_xunlock(&proctree_lock);
777 td->td_retval[0] = p->p_pid;
778 p->p_flag &= ~P_CONTINUED;
779 PROC_UNLOCK(p);
780
781 if (uap->status) {
782 status = SIGCONT;
783 error = copyout(&status,
784 uap->status, sizeof(status));
785 } else
786 error = 0;
787
788 mtx_unlock(&Giant);
789 return (error);
790 }
791 PROC_UNLOCK(p);
792 }
793 if (nfound == 0) {
794 sx_xunlock(&proctree_lock);
795 mtx_unlock(&Giant);
796 return (ECHILD);
797 }
798 if (uap->options & WNOHANG) {
799 sx_xunlock(&proctree_lock);
800 td->td_retval[0] = 0;
801 mtx_unlock(&Giant);
802 return (0);
803 }
804 PROC_LOCK(q);
805 sx_xunlock(&proctree_lock);
806 error = msleep(q, &q->p_mtx, PWAIT | PCATCH, "wait", 0);
807 PROC_UNLOCK(q);
808 if (error) {
809 mtx_unlock(&Giant);
810 return (error);
811 }
812 goto loop;
813}
814
815/*
816 * Make process 'parent' the new parent of process 'child'.
817 * Must be called with an exclusive hold of proctree lock.
818 */
819void
820proc_reparent(child, parent)
821 register struct proc *child;
822 register struct proc *parent;
823{
824
825 sx_assert(&proctree_lock, SX_XLOCKED);
826 PROC_LOCK_ASSERT(child, MA_OWNED);
827 if (child->p_pptr == parent)
828 return;
829
830 LIST_REMOVE(child, p_sibling);
831 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
832 child->p_pptr = parent;
833}
834
835/*
836 * The next two functions are to handle adding/deleting items on the
837 * exit callout list
838 *
839 * at_exit():
840 * Take the arguments given and put them onto the exit callout list,
841 * However first make sure that it's not already there.
842 * returns 0 on success.
843 */
844
845int
846at_exit(function)
847 exitlist_fn function;
848{
849 struct exitlist *ep;
850
851#ifdef INVARIANTS
852 /* Be noisy if the programmer has lost track of things */
853 if (rm_at_exit(function))
854 printf("WARNING: exit callout entry (%p) already present\n",
855 function);
856#endif
857 ep = malloc(sizeof(*ep), M_ATEXIT, M_NOWAIT);
858 if (ep == NULL)
859 return (ENOMEM);
860 ep->function = function;
861 TAILQ_INSERT_TAIL(&exit_list, ep, next);
862 return (0);
863}
864
865/*
866 * Scan the exit callout list for the given item and remove it.
867 * Returns the number of items removed (0 or 1)
868 */
869int
870rm_at_exit(function)
871 exitlist_fn function;
872{
873 struct exitlist *ep;
874
875 TAILQ_FOREACH(ep, &exit_list, next) {
876 if (ep->function == function) {
877 TAILQ_REMOVE(&exit_list, ep, next);
878 free(ep, M_ATEXIT);
879 return (1);
880 }
881 }
882 return (0);
883}
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