1 | /* $NetBSD: sysv_sem.c,v 1.95 2015/11/06 02:26:42 pgoyette Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 1999, 2007 The NetBSD Foundation, Inc. |
5 | * All rights reserved. |
6 | * |
7 | * This code is derived from software contributed to The NetBSD Foundation |
8 | * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, |
9 | * NASA Ames Research Center, and by Andrew Doran. |
10 | * |
11 | * Redistribution and use in source and binary forms, with or without |
12 | * modification, are permitted provided that the following conditions |
13 | * are met: |
14 | * 1. Redistributions of source code must retain the above copyright |
15 | * notice, this list of conditions and the following disclaimer. |
16 | * 2. Redistributions in binary form must reproduce the above copyright |
17 | * notice, this list of conditions and the following disclaimer in the |
18 | * documentation and/or other materials provided with the distribution. |
19 | * |
20 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
21 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
22 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
23 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
24 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
25 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
26 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
27 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
28 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
29 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
30 | * POSSIBILITY OF SUCH DAMAGE. |
31 | */ |
32 | |
33 | /* |
34 | * Implementation of SVID semaphores |
35 | * |
36 | * Author: Daniel Boulet |
37 | * |
38 | * This software is provided ``AS IS'' without any warranties of any kind. |
39 | */ |
40 | |
41 | #include <sys/cdefs.h> |
42 | __KERNEL_RCSID(0, "$NetBSD: sysv_sem.c,v 1.95 2015/11/06 02:26:42 pgoyette Exp $" ); |
43 | |
44 | #ifdef _KERNEL_OPT |
45 | #include "opt_sysv.h" |
46 | #endif |
47 | |
48 | #include <sys/param.h> |
49 | #include <sys/kernel.h> |
50 | #include <sys/sem.h> |
51 | #include <sys/sysctl.h> |
52 | #include <sys/kmem.h> |
53 | #include <sys/mount.h> /* XXX for <sys/syscallargs.h> */ |
54 | #include <sys/syscallargs.h> |
55 | #include <sys/kauth.h> |
56 | #include <sys/once.h> |
57 | |
58 | /* |
59 | * Memory areas: |
60 | * 1st: Pool of semaphore identifiers |
61 | * 2nd: Semaphores |
62 | * 3rd: Conditional variables |
63 | * 4th: Undo structures |
64 | */ |
65 | struct semid_ds * sema __read_mostly; |
66 | static struct __sem * sem __read_mostly; |
67 | static kcondvar_t * semcv __read_mostly; |
68 | static int * semu __read_mostly; |
69 | |
70 | static kmutex_t semlock __cacheline_aligned; |
71 | static bool sem_realloc_state __read_mostly; |
72 | static kcondvar_t sem_realloc_cv; |
73 | |
74 | /* |
75 | * List of active undo structures, total number of semaphores, |
76 | * and total number of semop waiters. |
77 | */ |
78 | static struct sem_undo *semu_list __read_mostly; |
79 | static u_int semtot __cacheline_aligned; |
80 | static u_int sem_waiters __cacheline_aligned; |
81 | |
82 | /* Macro to find a particular sem_undo vector */ |
83 | #define SEMU(s, ix) ((struct sem_undo *)(((long)s) + ix * seminfo.semusz)) |
84 | |
85 | #ifdef SEM_DEBUG |
86 | #define SEM_PRINTF(a) printf a |
87 | #else |
88 | #define SEM_PRINTF(a) |
89 | #endif |
90 | |
91 | void *hook; /* cookie from exithook_establish() */ |
92 | |
93 | extern int kern_has_sysvsem; |
94 | |
95 | SYSCTL_SETUP_PROTO(sysctl_ipc_sem_setup); |
96 | |
97 | struct sem_undo *semu_alloc(struct proc *); |
98 | int semundo_adjust(struct proc *, struct sem_undo **, int, int, int); |
99 | void semundo_clear(int, int); |
100 | |
101 | static ONCE_DECL(exithook_control); |
102 | static int seminit_exithook(void); |
103 | |
104 | void |
105 | seminit(struct sysctllog **clog) |
106 | { |
107 | int i, sz; |
108 | vaddr_t v; |
109 | |
110 | mutex_init(&semlock, MUTEX_DEFAULT, IPL_NONE); |
111 | cv_init(&sem_realloc_cv, "semrealc" ); |
112 | sem_realloc_state = false; |
113 | semtot = 0; |
114 | sem_waiters = 0; |
115 | |
116 | /* Allocate the wired memory for our structures */ |
117 | sz = ALIGN(seminfo.semmni * sizeof(struct semid_ds)) + |
118 | ALIGN(seminfo.semmns * sizeof(struct __sem)) + |
119 | ALIGN(seminfo.semmni * sizeof(kcondvar_t)) + |
120 | ALIGN(seminfo.semmnu * seminfo.semusz); |
121 | sz = round_page(sz); |
122 | v = uvm_km_alloc(kernel_map, sz, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); |
123 | if (v == 0) |
124 | panic("sysv_sem: cannot allocate memory" ); |
125 | sema = (void *)v; |
126 | sem = (void *)((uintptr_t)sema + |
127 | ALIGN(seminfo.semmni * sizeof(struct semid_ds))); |
128 | semcv = (void *)((uintptr_t)sem + |
129 | ALIGN(seminfo.semmns * sizeof(struct __sem))); |
130 | semu = (void *)((uintptr_t)semcv + |
131 | ALIGN(seminfo.semmni * sizeof(kcondvar_t))); |
132 | |
133 | for (i = 0; i < seminfo.semmni; i++) { |
134 | sema[i]._sem_base = 0; |
135 | sema[i].sem_perm.mode = 0; |
136 | cv_init(&semcv[i], "semwait" ); |
137 | } |
138 | for (i = 0; i < seminfo.semmnu; i++) { |
139 | struct sem_undo *suptr = SEMU(semu, i); |
140 | suptr->un_proc = NULL; |
141 | } |
142 | semu_list = NULL; |
143 | |
144 | kern_has_sysvsem = 1; |
145 | |
146 | #ifdef _MODULE |
147 | if (clog) |
148 | sysctl_ipc_sem_setup(clog); |
149 | #endif |
150 | } |
151 | |
152 | static int |
153 | seminit_exithook(void) |
154 | { |
155 | |
156 | hook = exithook_establish(semexit, NULL); |
157 | return 0; |
158 | } |
159 | |
160 | int |
161 | semfini(void) |
162 | { |
163 | int i, sz; |
164 | vaddr_t v = (vaddr_t)sema; |
165 | |
166 | /* Don't allow module unload if we're busy */ |
167 | mutex_enter(&semlock); |
168 | if (semtot) { |
169 | mutex_exit(&semlock); |
170 | return 1; |
171 | } |
172 | |
173 | /* Remove the exit hook */ |
174 | if (hook) |
175 | exithook_disestablish(hook); |
176 | |
177 | /* Destroy all our condvars */ |
178 | for (i = 0; i < seminfo.semmni; i++) { |
179 | cv_destroy(&semcv[i]); |
180 | } |
181 | |
182 | /* Free the wired memory that we allocated */ |
183 | sz = ALIGN(seminfo.semmni * sizeof(struct semid_ds)) + |
184 | ALIGN(seminfo.semmns * sizeof(struct __sem)) + |
185 | ALIGN(seminfo.semmni * sizeof(kcondvar_t)) + |
186 | ALIGN(seminfo.semmnu * seminfo.semusz); |
187 | sz = round_page(sz); |
188 | uvm_km_free(kernel_map, v, sz, UVM_KMF_WIRED); |
189 | |
190 | /* Destroy the last cv and mutex */ |
191 | cv_destroy(&sem_realloc_cv); |
192 | mutex_exit(&semlock); |
193 | mutex_destroy(&semlock); |
194 | |
195 | kern_has_sysvsem = 0; |
196 | |
197 | return 0; |
198 | } |
199 | |
200 | static int |
201 | semrealloc(int newsemmni, int newsemmns, int newsemmnu) |
202 | { |
203 | struct semid_ds *new_sema, *old_sema; |
204 | struct __sem *new_sem; |
205 | struct sem_undo *new_semu_list, *suptr, *nsuptr; |
206 | int *new_semu; |
207 | kcondvar_t *new_semcv; |
208 | vaddr_t v; |
209 | int i, j, lsemid, nmnus, sz; |
210 | |
211 | if (newsemmni < 1 || newsemmns < 1 || newsemmnu < 1) |
212 | return EINVAL; |
213 | |
214 | /* Allocate the wired memory for our structures */ |
215 | sz = ALIGN(newsemmni * sizeof(struct semid_ds)) + |
216 | ALIGN(newsemmns * sizeof(struct __sem)) + |
217 | ALIGN(newsemmni * sizeof(kcondvar_t)) + |
218 | ALIGN(newsemmnu * seminfo.semusz); |
219 | sz = round_page(sz); |
220 | v = uvm_km_alloc(kernel_map, sz, 0, UVM_KMF_WIRED|UVM_KMF_ZERO); |
221 | if (v == 0) |
222 | return ENOMEM; |
223 | |
224 | mutex_enter(&semlock); |
225 | if (sem_realloc_state) { |
226 | mutex_exit(&semlock); |
227 | uvm_km_free(kernel_map, v, sz, UVM_KMF_WIRED); |
228 | return EBUSY; |
229 | } |
230 | sem_realloc_state = true; |
231 | if (sem_waiters) { |
232 | /* |
233 | * Mark reallocation state, wake-up all waiters, |
234 | * and wait while they will all exit. |
235 | */ |
236 | for (i = 0; i < seminfo.semmni; i++) |
237 | cv_broadcast(&semcv[i]); |
238 | while (sem_waiters) |
239 | cv_wait(&sem_realloc_cv, &semlock); |
240 | } |
241 | old_sema = sema; |
242 | |
243 | /* Get the number of last slot */ |
244 | lsemid = 0; |
245 | for (i = 0; i < seminfo.semmni; i++) |
246 | if (sema[i].sem_perm.mode & SEM_ALLOC) |
247 | lsemid = i; |
248 | |
249 | /* Get the number of currently used undo structures */ |
250 | nmnus = 0; |
251 | for (i = 0; i < seminfo.semmnu; i++) { |
252 | suptr = SEMU(semu, i); |
253 | if (suptr->un_proc == NULL) |
254 | continue; |
255 | nmnus++; |
256 | } |
257 | |
258 | /* We cannot reallocate less memory than we use */ |
259 | if (lsemid >= newsemmni || semtot > newsemmns || nmnus > newsemmnu) { |
260 | mutex_exit(&semlock); |
261 | uvm_km_free(kernel_map, v, sz, UVM_KMF_WIRED); |
262 | return EBUSY; |
263 | } |
264 | |
265 | new_sema = (void *)v; |
266 | new_sem = (void *)((uintptr_t)new_sema + |
267 | ALIGN(newsemmni * sizeof(struct semid_ds))); |
268 | new_semcv = (void *)((uintptr_t)new_sem + |
269 | ALIGN(newsemmns * sizeof(struct __sem))); |
270 | new_semu = (void *)((uintptr_t)new_semcv + |
271 | ALIGN(newsemmni * sizeof(kcondvar_t))); |
272 | |
273 | /* Initialize all semaphore identifiers and condvars */ |
274 | for (i = 0; i < newsemmni; i++) { |
275 | new_sema[i]._sem_base = 0; |
276 | new_sema[i].sem_perm.mode = 0; |
277 | cv_init(&new_semcv[i], "semwait" ); |
278 | } |
279 | for (i = 0; i < newsemmnu; i++) { |
280 | nsuptr = SEMU(new_semu, i); |
281 | nsuptr->un_proc = NULL; |
282 | } |
283 | |
284 | /* |
285 | * Copy all identifiers, semaphores and list of the |
286 | * undo structures to the new memory allocation. |
287 | */ |
288 | j = 0; |
289 | for (i = 0; i <= lsemid; i++) { |
290 | if ((sema[i].sem_perm.mode & SEM_ALLOC) == 0) |
291 | continue; |
292 | memcpy(&new_sema[i], &sema[i], sizeof(struct semid_ds)); |
293 | new_sema[i]._sem_base = &new_sem[j]; |
294 | memcpy(new_sema[i]._sem_base, sema[i]._sem_base, |
295 | (sizeof(struct __sem) * sema[i].sem_nsems)); |
296 | j += sema[i].sem_nsems; |
297 | } |
298 | KASSERT(j == semtot); |
299 | |
300 | j = 0; |
301 | new_semu_list = NULL; |
302 | for (suptr = semu_list; suptr != NULL; suptr = suptr->un_next) { |
303 | KASSERT(j < newsemmnu); |
304 | nsuptr = SEMU(new_semu, j); |
305 | memcpy(nsuptr, suptr, SEMUSZ); |
306 | nsuptr->un_next = new_semu_list; |
307 | new_semu_list = nsuptr; |
308 | j++; |
309 | } |
310 | |
311 | for (i = 0; i < seminfo.semmni; i++) { |
312 | KASSERT(cv_has_waiters(&semcv[i]) == false); |
313 | cv_destroy(&semcv[i]); |
314 | } |
315 | |
316 | sz = ALIGN(seminfo.semmni * sizeof(struct semid_ds)) + |
317 | ALIGN(seminfo.semmns * sizeof(struct __sem)) + |
318 | ALIGN(seminfo.semmni * sizeof(kcondvar_t)) + |
319 | ALIGN(seminfo.semmnu * seminfo.semusz); |
320 | sz = round_page(sz); |
321 | |
322 | /* Set the pointers and update the new values */ |
323 | sema = new_sema; |
324 | sem = new_sem; |
325 | semcv = new_semcv; |
326 | semu = new_semu; |
327 | semu_list = new_semu_list; |
328 | |
329 | seminfo.semmni = newsemmni; |
330 | seminfo.semmns = newsemmns; |
331 | seminfo.semmnu = newsemmnu; |
332 | |
333 | /* Reallocation completed - notify all waiters, if any */ |
334 | sem_realloc_state = false; |
335 | cv_broadcast(&sem_realloc_cv); |
336 | mutex_exit(&semlock); |
337 | |
338 | uvm_km_free(kernel_map, (vaddr_t)old_sema, sz, UVM_KMF_WIRED); |
339 | return 0; |
340 | } |
341 | |
342 | /* |
343 | * Placebo. |
344 | */ |
345 | |
346 | int |
347 | sys_semconfig(struct lwp *l, const struct sys_semconfig_args *uap, register_t *retval) |
348 | { |
349 | |
350 | RUN_ONCE(&exithook_control, seminit_exithook); |
351 | |
352 | *retval = 0; |
353 | return 0; |
354 | } |
355 | |
356 | /* |
357 | * Allocate a new sem_undo structure for a process. |
358 | * => Returns NULL on failure. |
359 | */ |
360 | struct sem_undo * |
361 | semu_alloc(struct proc *p) |
362 | { |
363 | struct sem_undo *suptr, **supptr; |
364 | bool attempted = false; |
365 | int i; |
366 | |
367 | KASSERT(mutex_owned(&semlock)); |
368 | again: |
369 | /* Look for a free structure. */ |
370 | for (i = 0; i < seminfo.semmnu; i++) { |
371 | suptr = SEMU(semu, i); |
372 | if (suptr->un_proc == NULL) { |
373 | /* Found. Fill it in and return. */ |
374 | suptr->un_next = semu_list; |
375 | semu_list = suptr; |
376 | suptr->un_cnt = 0; |
377 | suptr->un_proc = p; |
378 | return suptr; |
379 | } |
380 | } |
381 | |
382 | /* Not found. Attempt to free some structures. */ |
383 | if (!attempted) { |
384 | bool freed = false; |
385 | |
386 | attempted = true; |
387 | supptr = &semu_list; |
388 | while ((suptr = *supptr) != NULL) { |
389 | if (suptr->un_cnt == 0) { |
390 | suptr->un_proc = NULL; |
391 | *supptr = suptr->un_next; |
392 | freed = true; |
393 | } else { |
394 | supptr = &suptr->un_next; |
395 | } |
396 | } |
397 | if (freed) { |
398 | goto again; |
399 | } |
400 | } |
401 | return NULL; |
402 | } |
403 | |
404 | /* |
405 | * Adjust a particular entry for a particular proc |
406 | */ |
407 | |
408 | int |
409 | semundo_adjust(struct proc *p, struct sem_undo **supptr, int semid, int semnum, |
410 | int adjval) |
411 | { |
412 | struct sem_undo *suptr; |
413 | struct sem_undo_entry *sunptr; |
414 | int i; |
415 | |
416 | KASSERT(mutex_owned(&semlock)); |
417 | |
418 | /* |
419 | * Look for and remember the sem_undo if the caller doesn't |
420 | * provide it |
421 | */ |
422 | |
423 | suptr = *supptr; |
424 | if (suptr == NULL) { |
425 | for (suptr = semu_list; suptr != NULL; suptr = suptr->un_next) |
426 | if (suptr->un_proc == p) |
427 | break; |
428 | |
429 | if (suptr == NULL) { |
430 | suptr = semu_alloc(p); |
431 | if (suptr == NULL) |
432 | return (ENOSPC); |
433 | } |
434 | *supptr = suptr; |
435 | } |
436 | |
437 | /* |
438 | * Look for the requested entry and adjust it (delete if |
439 | * adjval becomes 0). |
440 | */ |
441 | sunptr = &suptr->un_ent[0]; |
442 | for (i = 0; i < suptr->un_cnt; i++, sunptr++) { |
443 | if (sunptr->un_id != semid || sunptr->un_num != semnum) |
444 | continue; |
445 | sunptr->un_adjval += adjval; |
446 | if (sunptr->un_adjval == 0) { |
447 | suptr->un_cnt--; |
448 | if (i < suptr->un_cnt) |
449 | suptr->un_ent[i] = |
450 | suptr->un_ent[suptr->un_cnt]; |
451 | } |
452 | return (0); |
453 | } |
454 | |
455 | /* Didn't find the right entry - create it */ |
456 | if (suptr->un_cnt == SEMUME) |
457 | return (EINVAL); |
458 | |
459 | sunptr = &suptr->un_ent[suptr->un_cnt]; |
460 | suptr->un_cnt++; |
461 | sunptr->un_adjval = adjval; |
462 | sunptr->un_id = semid; |
463 | sunptr->un_num = semnum; |
464 | return (0); |
465 | } |
466 | |
467 | void |
468 | semundo_clear(int semid, int semnum) |
469 | { |
470 | struct sem_undo *suptr; |
471 | struct sem_undo_entry *sunptr, *sunend; |
472 | |
473 | KASSERT(mutex_owned(&semlock)); |
474 | |
475 | for (suptr = semu_list; suptr != NULL; suptr = suptr->un_next) |
476 | for (sunptr = &suptr->un_ent[0], |
477 | sunend = sunptr + suptr->un_cnt; sunptr < sunend;) { |
478 | if (sunptr->un_id == semid) { |
479 | if (semnum == -1 || sunptr->un_num == semnum) { |
480 | suptr->un_cnt--; |
481 | sunend--; |
482 | if (sunptr != sunend) |
483 | *sunptr = *sunend; |
484 | if (semnum != -1) |
485 | break; |
486 | else |
487 | continue; |
488 | } |
489 | } |
490 | sunptr++; |
491 | } |
492 | } |
493 | |
494 | int |
495 | sys_____semctl50(struct lwp *l, const struct sys_____semctl50_args *uap, |
496 | register_t *retval) |
497 | { |
498 | /* { |
499 | syscallarg(int) semid; |
500 | syscallarg(int) semnum; |
501 | syscallarg(int) cmd; |
502 | syscallarg(union __semun *) arg; |
503 | } */ |
504 | struct semid_ds sembuf; |
505 | int cmd, error; |
506 | void *pass_arg; |
507 | union __semun karg; |
508 | |
509 | RUN_ONCE(&exithook_control, seminit_exithook); |
510 | |
511 | cmd = SCARG(uap, cmd); |
512 | |
513 | pass_arg = get_semctl_arg(cmd, &sembuf, &karg); |
514 | |
515 | if (pass_arg) { |
516 | error = copyin(SCARG(uap, arg), &karg, sizeof(karg)); |
517 | if (error) |
518 | return error; |
519 | if (cmd == IPC_SET) { |
520 | error = copyin(karg.buf, &sembuf, sizeof(sembuf)); |
521 | if (error) |
522 | return (error); |
523 | } |
524 | } |
525 | |
526 | error = semctl1(l, SCARG(uap, semid), SCARG(uap, semnum), cmd, |
527 | pass_arg, retval); |
528 | |
529 | if (error == 0 && cmd == IPC_STAT) |
530 | error = copyout(&sembuf, karg.buf, sizeof(sembuf)); |
531 | |
532 | return (error); |
533 | } |
534 | |
535 | int |
536 | semctl1(struct lwp *l, int semid, int semnum, int cmd, void *v, |
537 | register_t *retval) |
538 | { |
539 | kauth_cred_t cred = l->l_cred; |
540 | union __semun *arg = v; |
541 | struct semid_ds *sembuf = v, *semaptr; |
542 | int i, error, ix; |
543 | |
544 | SEM_PRINTF(("call to semctl(%d, %d, %d, %p)\n" , |
545 | semid, semnum, cmd, v)); |
546 | |
547 | mutex_enter(&semlock); |
548 | |
549 | ix = IPCID_TO_IX(semid); |
550 | if (ix < 0 || ix >= seminfo.semmni) { |
551 | mutex_exit(&semlock); |
552 | return (EINVAL); |
553 | } |
554 | |
555 | semaptr = &sema[ix]; |
556 | if ((semaptr->sem_perm.mode & SEM_ALLOC) == 0 || |
557 | semaptr->sem_perm._seq != IPCID_TO_SEQ(semid)) { |
558 | mutex_exit(&semlock); |
559 | return (EINVAL); |
560 | } |
561 | |
562 | switch (cmd) { |
563 | case IPC_RMID: |
564 | if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_M)) != 0) |
565 | break; |
566 | semaptr->sem_perm.cuid = kauth_cred_geteuid(cred); |
567 | semaptr->sem_perm.uid = kauth_cred_geteuid(cred); |
568 | semtot -= semaptr->sem_nsems; |
569 | for (i = semaptr->_sem_base - sem; i < semtot; i++) |
570 | sem[i] = sem[i + semaptr->sem_nsems]; |
571 | for (i = 0; i < seminfo.semmni; i++) { |
572 | if ((sema[i].sem_perm.mode & SEM_ALLOC) && |
573 | sema[i]._sem_base > semaptr->_sem_base) |
574 | sema[i]._sem_base -= semaptr->sem_nsems; |
575 | } |
576 | semaptr->sem_perm.mode = 0; |
577 | semundo_clear(ix, -1); |
578 | cv_broadcast(&semcv[ix]); |
579 | break; |
580 | |
581 | case IPC_SET: |
582 | if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_M))) |
583 | break; |
584 | KASSERT(sembuf != NULL); |
585 | semaptr->sem_perm.uid = sembuf->sem_perm.uid; |
586 | semaptr->sem_perm.gid = sembuf->sem_perm.gid; |
587 | semaptr->sem_perm.mode = (semaptr->sem_perm.mode & ~0777) | |
588 | (sembuf->sem_perm.mode & 0777); |
589 | semaptr->sem_ctime = time_second; |
590 | break; |
591 | |
592 | case IPC_STAT: |
593 | if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R))) |
594 | break; |
595 | KASSERT(sembuf != NULL); |
596 | memcpy(sembuf, semaptr, sizeof(struct semid_ds)); |
597 | sembuf->sem_perm.mode &= 0777; |
598 | break; |
599 | |
600 | case GETNCNT: |
601 | if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R))) |
602 | break; |
603 | if (semnum < 0 || semnum >= semaptr->sem_nsems) { |
604 | error = EINVAL; |
605 | break; |
606 | } |
607 | *retval = semaptr->_sem_base[semnum].semncnt; |
608 | break; |
609 | |
610 | case GETPID: |
611 | if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R))) |
612 | break; |
613 | if (semnum < 0 || semnum >= semaptr->sem_nsems) { |
614 | error = EINVAL; |
615 | break; |
616 | } |
617 | *retval = semaptr->_sem_base[semnum].sempid; |
618 | break; |
619 | |
620 | case GETVAL: |
621 | if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R))) |
622 | break; |
623 | if (semnum < 0 || semnum >= semaptr->sem_nsems) { |
624 | error = EINVAL; |
625 | break; |
626 | } |
627 | *retval = semaptr->_sem_base[semnum].semval; |
628 | break; |
629 | |
630 | case GETALL: |
631 | if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R))) |
632 | break; |
633 | KASSERT(arg != NULL); |
634 | for (i = 0; i < semaptr->sem_nsems; i++) { |
635 | error = copyout(&semaptr->_sem_base[i].semval, |
636 | &arg->array[i], sizeof(arg->array[i])); |
637 | if (error != 0) |
638 | break; |
639 | } |
640 | break; |
641 | |
642 | case GETZCNT: |
643 | if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R))) |
644 | break; |
645 | if (semnum < 0 || semnum >= semaptr->sem_nsems) { |
646 | error = EINVAL; |
647 | break; |
648 | } |
649 | *retval = semaptr->_sem_base[semnum].semzcnt; |
650 | break; |
651 | |
652 | case SETVAL: |
653 | if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_W))) |
654 | break; |
655 | if (semnum < 0 || semnum >= semaptr->sem_nsems) { |
656 | error = EINVAL; |
657 | break; |
658 | } |
659 | KASSERT(arg != NULL); |
660 | if ((unsigned int)arg->val > seminfo.semvmx) { |
661 | error = ERANGE; |
662 | break; |
663 | } |
664 | semaptr->_sem_base[semnum].semval = arg->val; |
665 | semundo_clear(ix, semnum); |
666 | cv_broadcast(&semcv[ix]); |
667 | break; |
668 | |
669 | case SETALL: |
670 | if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_W))) |
671 | break; |
672 | KASSERT(arg != NULL); |
673 | for (i = 0; i < semaptr->sem_nsems; i++) { |
674 | unsigned short semval; |
675 | error = copyin(&arg->array[i], &semval, |
676 | sizeof(arg->array[i])); |
677 | if (error != 0) |
678 | break; |
679 | if ((unsigned int)semval > seminfo.semvmx) { |
680 | error = ERANGE; |
681 | break; |
682 | } |
683 | semaptr->_sem_base[i].semval = semval; |
684 | } |
685 | semundo_clear(ix, -1); |
686 | cv_broadcast(&semcv[ix]); |
687 | break; |
688 | |
689 | default: |
690 | error = EINVAL; |
691 | break; |
692 | } |
693 | |
694 | mutex_exit(&semlock); |
695 | return (error); |
696 | } |
697 | |
698 | int |
699 | sys_semget(struct lwp *l, const struct sys_semget_args *uap, register_t *retval) |
700 | { |
701 | /* { |
702 | syscallarg(key_t) key; |
703 | syscallarg(int) nsems; |
704 | syscallarg(int) semflg; |
705 | } */ |
706 | int semid, error = 0; |
707 | int key = SCARG(uap, key); |
708 | int nsems = SCARG(uap, nsems); |
709 | int semflg = SCARG(uap, semflg); |
710 | kauth_cred_t cred = l->l_cred; |
711 | |
712 | RUN_ONCE(&exithook_control, seminit_exithook); |
713 | |
714 | SEM_PRINTF(("semget(0x%x, %d, 0%o)\n" , key, nsems, semflg)); |
715 | |
716 | mutex_enter(&semlock); |
717 | |
718 | if (key != IPC_PRIVATE) { |
719 | for (semid = 0; semid < seminfo.semmni; semid++) { |
720 | if ((sema[semid].sem_perm.mode & SEM_ALLOC) && |
721 | sema[semid].sem_perm._key == key) |
722 | break; |
723 | } |
724 | if (semid < seminfo.semmni) { |
725 | SEM_PRINTF(("found public key\n" )); |
726 | if ((error = ipcperm(cred, &sema[semid].sem_perm, |
727 | semflg & 0700))) |
728 | goto out; |
729 | if (nsems > 0 && sema[semid].sem_nsems < nsems) { |
730 | SEM_PRINTF(("too small\n" )); |
731 | error = EINVAL; |
732 | goto out; |
733 | } |
734 | if ((semflg & IPC_CREAT) && (semflg & IPC_EXCL)) { |
735 | SEM_PRINTF(("not exclusive\n" )); |
736 | error = EEXIST; |
737 | goto out; |
738 | } |
739 | goto found; |
740 | } |
741 | } |
742 | |
743 | SEM_PRINTF(("need to allocate the semid_ds\n" )); |
744 | if (key == IPC_PRIVATE || (semflg & IPC_CREAT)) { |
745 | if (nsems <= 0 || nsems > seminfo.semmsl) { |
746 | SEM_PRINTF(("nsems out of range (0<%d<=%d)\n" , nsems, |
747 | seminfo.semmsl)); |
748 | error = EINVAL; |
749 | goto out; |
750 | } |
751 | if (nsems > seminfo.semmns - semtot) { |
752 | SEM_PRINTF(("not enough semaphores left " |
753 | "(need %d, got %d)\n" , |
754 | nsems, seminfo.semmns - semtot)); |
755 | error = ENOSPC; |
756 | goto out; |
757 | } |
758 | for (semid = 0; semid < seminfo.semmni; semid++) { |
759 | if ((sema[semid].sem_perm.mode & SEM_ALLOC) == 0) |
760 | break; |
761 | } |
762 | if (semid == seminfo.semmni) { |
763 | SEM_PRINTF(("no more semid_ds's available\n" )); |
764 | error = ENOSPC; |
765 | goto out; |
766 | } |
767 | SEM_PRINTF(("semid %d is available\n" , semid)); |
768 | sema[semid].sem_perm._key = key; |
769 | sema[semid].sem_perm.cuid = kauth_cred_geteuid(cred); |
770 | sema[semid].sem_perm.uid = kauth_cred_geteuid(cred); |
771 | sema[semid].sem_perm.cgid = kauth_cred_getegid(cred); |
772 | sema[semid].sem_perm.gid = kauth_cred_getegid(cred); |
773 | sema[semid].sem_perm.mode = (semflg & 0777) | SEM_ALLOC; |
774 | sema[semid].sem_perm._seq = |
775 | (sema[semid].sem_perm._seq + 1) & 0x7fff; |
776 | sema[semid].sem_nsems = nsems; |
777 | sema[semid].sem_otime = 0; |
778 | sema[semid].sem_ctime = time_second; |
779 | sema[semid]._sem_base = &sem[semtot]; |
780 | semtot += nsems; |
781 | memset(sema[semid]._sem_base, 0, |
782 | sizeof(sema[semid]._sem_base[0]) * nsems); |
783 | SEM_PRINTF(("sembase = %p, next = %p\n" , sema[semid]._sem_base, |
784 | &sem[semtot])); |
785 | } else { |
786 | SEM_PRINTF(("didn't find it and wasn't asked to create it\n" )); |
787 | error = ENOENT; |
788 | goto out; |
789 | } |
790 | |
791 | found: |
792 | *retval = IXSEQ_TO_IPCID(semid, sema[semid].sem_perm); |
793 | out: |
794 | mutex_exit(&semlock); |
795 | return (error); |
796 | } |
797 | |
798 | #define SMALL_SOPS 8 |
799 | |
800 | int |
801 | sys_semop(struct lwp *l, const struct sys_semop_args *uap, register_t *retval) |
802 | { |
803 | /* { |
804 | syscallarg(int) semid; |
805 | syscallarg(struct sembuf *) sops; |
806 | syscallarg(size_t) nsops; |
807 | } */ |
808 | struct proc *p = l->l_proc; |
809 | int semid = SCARG(uap, semid), seq; |
810 | size_t nsops = SCARG(uap, nsops); |
811 | struct sembuf small_sops[SMALL_SOPS]; |
812 | struct sembuf *sops; |
813 | struct semid_ds *semaptr; |
814 | struct sembuf *sopptr = NULL; |
815 | struct __sem *semptr = NULL; |
816 | struct sem_undo *suptr = NULL; |
817 | kauth_cred_t cred = l->l_cred; |
818 | int i, error; |
819 | int do_wakeup, do_undos; |
820 | |
821 | RUN_ONCE(&exithook_control, seminit_exithook); |
822 | |
823 | SEM_PRINTF(("call to semop(%d, %p, %zd)\n" , semid, SCARG(uap,sops), nsops)); |
824 | |
825 | if (__predict_false((p->p_flag & PK_SYSVSEM) == 0)) { |
826 | mutex_enter(p->p_lock); |
827 | p->p_flag |= PK_SYSVSEM; |
828 | mutex_exit(p->p_lock); |
829 | } |
830 | |
831 | restart: |
832 | if (nsops <= SMALL_SOPS) { |
833 | sops = small_sops; |
834 | } else if (nsops <= seminfo.semopm) { |
835 | sops = kmem_alloc(nsops * sizeof(*sops), KM_SLEEP); |
836 | } else { |
837 | SEM_PRINTF(("too many sops (max=%d, nsops=%zd)\n" , |
838 | seminfo.semopm, nsops)); |
839 | return (E2BIG); |
840 | } |
841 | |
842 | error = copyin(SCARG(uap, sops), sops, nsops * sizeof(sops[0])); |
843 | if (error) { |
844 | SEM_PRINTF(("error = %d from copyin(%p, %p, %zd)\n" , error, |
845 | SCARG(uap, sops), &sops, nsops * sizeof(sops[0]))); |
846 | if (sops != small_sops) |
847 | kmem_free(sops, nsops * sizeof(*sops)); |
848 | return error; |
849 | } |
850 | |
851 | mutex_enter(&semlock); |
852 | /* In case of reallocation, we will wait for completion */ |
853 | while (__predict_false(sem_realloc_state)) |
854 | cv_wait(&sem_realloc_cv, &semlock); |
855 | |
856 | semid = IPCID_TO_IX(semid); /* Convert back to zero origin */ |
857 | if (semid < 0 || semid >= seminfo.semmni) { |
858 | error = EINVAL; |
859 | goto out; |
860 | } |
861 | |
862 | semaptr = &sema[semid]; |
863 | seq = IPCID_TO_SEQ(SCARG(uap, semid)); |
864 | if ((semaptr->sem_perm.mode & SEM_ALLOC) == 0 || |
865 | semaptr->sem_perm._seq != seq) { |
866 | error = EINVAL; |
867 | goto out; |
868 | } |
869 | |
870 | if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_W))) { |
871 | SEM_PRINTF(("error = %d from ipaccess\n" , error)); |
872 | goto out; |
873 | } |
874 | |
875 | for (i = 0; i < nsops; i++) |
876 | if (sops[i].sem_num >= semaptr->sem_nsems) { |
877 | error = EFBIG; |
878 | goto out; |
879 | } |
880 | |
881 | /* |
882 | * Loop trying to satisfy the vector of requests. |
883 | * If we reach a point where we must wait, any requests already |
884 | * performed are rolled back and we go to sleep until some other |
885 | * process wakes us up. At this point, we start all over again. |
886 | * |
887 | * This ensures that from the perspective of other tasks, a set |
888 | * of requests is atomic (never partially satisfied). |
889 | */ |
890 | do_undos = 0; |
891 | |
892 | for (;;) { |
893 | do_wakeup = 0; |
894 | |
895 | for (i = 0; i < nsops; i++) { |
896 | sopptr = &sops[i]; |
897 | semptr = &semaptr->_sem_base[sopptr->sem_num]; |
898 | |
899 | SEM_PRINTF(("semop: semaptr=%p, sem_base=%p, " |
900 | "semptr=%p, sem[%d]=%d : op=%d, flag=%s\n" , |
901 | semaptr, semaptr->_sem_base, semptr, |
902 | sopptr->sem_num, semptr->semval, sopptr->sem_op, |
903 | (sopptr->sem_flg & IPC_NOWAIT) ? |
904 | "nowait" : "wait" )); |
905 | |
906 | if (sopptr->sem_op < 0) { |
907 | if ((int)(semptr->semval + |
908 | sopptr->sem_op) < 0) { |
909 | SEM_PRINTF(("semop: " |
910 | "can't do it now\n" )); |
911 | break; |
912 | } else { |
913 | semptr->semval += sopptr->sem_op; |
914 | if (semptr->semval == 0 && |
915 | semptr->semzcnt > 0) |
916 | do_wakeup = 1; |
917 | } |
918 | if (sopptr->sem_flg & SEM_UNDO) |
919 | do_undos = 1; |
920 | } else if (sopptr->sem_op == 0) { |
921 | if (semptr->semval > 0) { |
922 | SEM_PRINTF(("semop: not zero now\n" )); |
923 | break; |
924 | } |
925 | } else { |
926 | if (semptr->semncnt > 0) |
927 | do_wakeup = 1; |
928 | semptr->semval += sopptr->sem_op; |
929 | if (sopptr->sem_flg & SEM_UNDO) |
930 | do_undos = 1; |
931 | } |
932 | } |
933 | |
934 | /* |
935 | * Did we get through the entire vector? |
936 | */ |
937 | if (i >= nsops) |
938 | goto done; |
939 | |
940 | /* |
941 | * No ... rollback anything that we've already done |
942 | */ |
943 | SEM_PRINTF(("semop: rollback 0 through %d\n" , i - 1)); |
944 | while (i-- > 0) |
945 | semaptr->_sem_base[sops[i].sem_num].semval -= |
946 | sops[i].sem_op; |
947 | |
948 | /* |
949 | * If the request that we couldn't satisfy has the |
950 | * NOWAIT flag set then return with EAGAIN. |
951 | */ |
952 | if (sopptr->sem_flg & IPC_NOWAIT) { |
953 | error = EAGAIN; |
954 | goto out; |
955 | } |
956 | |
957 | if (sopptr->sem_op == 0) |
958 | semptr->semzcnt++; |
959 | else |
960 | semptr->semncnt++; |
961 | |
962 | sem_waiters++; |
963 | SEM_PRINTF(("semop: good night!\n" )); |
964 | error = cv_wait_sig(&semcv[semid], &semlock); |
965 | SEM_PRINTF(("semop: good morning (error=%d)!\n" , error)); |
966 | sem_waiters--; |
967 | |
968 | /* Notify reallocator, if it is waiting */ |
969 | cv_broadcast(&sem_realloc_cv); |
970 | |
971 | /* |
972 | * Make sure that the semaphore still exists |
973 | */ |
974 | if ((semaptr->sem_perm.mode & SEM_ALLOC) == 0 || |
975 | semaptr->sem_perm._seq != seq) { |
976 | error = EIDRM; |
977 | goto out; |
978 | } |
979 | |
980 | /* |
981 | * The semaphore is still alive. Readjust the count of |
982 | * waiting processes. |
983 | */ |
984 | semptr = &semaptr->_sem_base[sopptr->sem_num]; |
985 | if (sopptr->sem_op == 0) |
986 | semptr->semzcnt--; |
987 | else |
988 | semptr->semncnt--; |
989 | |
990 | /* In case of such state, restart the call */ |
991 | if (sem_realloc_state) { |
992 | mutex_exit(&semlock); |
993 | goto restart; |
994 | } |
995 | |
996 | /* Is it really morning, or was our sleep interrupted? */ |
997 | if (error != 0) { |
998 | error = EINTR; |
999 | goto out; |
1000 | } |
1001 | SEM_PRINTF(("semop: good morning!\n" )); |
1002 | } |
1003 | |
1004 | done: |
1005 | /* |
1006 | * Process any SEM_UNDO requests. |
1007 | */ |
1008 | if (do_undos) { |
1009 | for (i = 0; i < nsops; i++) { |
1010 | /* |
1011 | * We only need to deal with SEM_UNDO's for non-zero |
1012 | * op's. |
1013 | */ |
1014 | int adjval; |
1015 | |
1016 | if ((sops[i].sem_flg & SEM_UNDO) == 0) |
1017 | continue; |
1018 | adjval = sops[i].sem_op; |
1019 | if (adjval == 0) |
1020 | continue; |
1021 | error = semundo_adjust(p, &suptr, semid, |
1022 | sops[i].sem_num, -adjval); |
1023 | if (error == 0) |
1024 | continue; |
1025 | |
1026 | /* |
1027 | * Oh-Oh! We ran out of either sem_undo's or undo's. |
1028 | * Rollback the adjustments to this point and then |
1029 | * rollback the semaphore ups and down so we can return |
1030 | * with an error with all structures restored. We |
1031 | * rollback the undo's in the exact reverse order that |
1032 | * we applied them. This guarantees that we won't run |
1033 | * out of space as we roll things back out. |
1034 | */ |
1035 | while (i-- > 0) { |
1036 | if ((sops[i].sem_flg & SEM_UNDO) == 0) |
1037 | continue; |
1038 | adjval = sops[i].sem_op; |
1039 | if (adjval == 0) |
1040 | continue; |
1041 | if (semundo_adjust(p, &suptr, semid, |
1042 | sops[i].sem_num, adjval) != 0) |
1043 | panic("semop - can't undo undos" ); |
1044 | } |
1045 | |
1046 | for (i = 0; i < nsops; i++) |
1047 | semaptr->_sem_base[sops[i].sem_num].semval -= |
1048 | sops[i].sem_op; |
1049 | |
1050 | SEM_PRINTF(("error = %d from semundo_adjust\n" , error)); |
1051 | goto out; |
1052 | } /* loop through the sops */ |
1053 | } /* if (do_undos) */ |
1054 | |
1055 | /* We're definitely done - set the sempid's */ |
1056 | for (i = 0; i < nsops; i++) { |
1057 | sopptr = &sops[i]; |
1058 | semptr = &semaptr->_sem_base[sopptr->sem_num]; |
1059 | semptr->sempid = p->p_pid; |
1060 | } |
1061 | |
1062 | /* Update sem_otime */ |
1063 | semaptr->sem_otime = time_second; |
1064 | |
1065 | /* Do a wakeup if any semaphore was up'd. */ |
1066 | if (do_wakeup) { |
1067 | SEM_PRINTF(("semop: doing wakeup\n" )); |
1068 | cv_broadcast(&semcv[semid]); |
1069 | SEM_PRINTF(("semop: back from wakeup\n" )); |
1070 | } |
1071 | SEM_PRINTF(("semop: done\n" )); |
1072 | *retval = 0; |
1073 | |
1074 | out: |
1075 | mutex_exit(&semlock); |
1076 | if (sops != small_sops) |
1077 | kmem_free(sops, nsops * sizeof(*sops)); |
1078 | return error; |
1079 | } |
1080 | |
1081 | /* |
1082 | * Go through the undo structures for this process and apply the |
1083 | * adjustments to semaphores. |
1084 | */ |
1085 | /*ARGSUSED*/ |
1086 | void |
1087 | semexit(struct proc *p, void *v) |
1088 | { |
1089 | struct sem_undo *suptr; |
1090 | struct sem_undo **supptr; |
1091 | |
1092 | if ((p->p_flag & PK_SYSVSEM) == 0) |
1093 | return; |
1094 | |
1095 | mutex_enter(&semlock); |
1096 | |
1097 | /* |
1098 | * Go through the chain of undo vectors looking for one |
1099 | * associated with this process. |
1100 | */ |
1101 | |
1102 | for (supptr = &semu_list; (suptr = *supptr) != NULL; |
1103 | supptr = &suptr->un_next) { |
1104 | if (suptr->un_proc == p) |
1105 | break; |
1106 | } |
1107 | |
1108 | /* |
1109 | * If there is no undo vector, skip to the end. |
1110 | */ |
1111 | |
1112 | if (suptr == NULL) { |
1113 | mutex_exit(&semlock); |
1114 | return; |
1115 | } |
1116 | |
1117 | /* |
1118 | * We now have an undo vector for this process. |
1119 | */ |
1120 | |
1121 | SEM_PRINTF(("proc @%p has undo structure with %d entries\n" , p, |
1122 | suptr->un_cnt)); |
1123 | |
1124 | /* |
1125 | * If there are any active undo elements then process them. |
1126 | */ |
1127 | if (suptr->un_cnt > 0) { |
1128 | int ix; |
1129 | |
1130 | for (ix = 0; ix < suptr->un_cnt; ix++) { |
1131 | int semid = suptr->un_ent[ix].un_id; |
1132 | int semnum = suptr->un_ent[ix].un_num; |
1133 | int adjval = suptr->un_ent[ix].un_adjval; |
1134 | struct semid_ds *semaptr; |
1135 | |
1136 | semaptr = &sema[semid]; |
1137 | if ((semaptr->sem_perm.mode & SEM_ALLOC) == 0) |
1138 | if (semnum >= semaptr->sem_nsems) |
1139 | panic("semexit - semnum out of range" ); |
1140 | |
1141 | SEM_PRINTF(("semexit: %p id=%d num=%d(adj=%d) ; " |
1142 | "sem=%d\n" , |
1143 | suptr->un_proc, suptr->un_ent[ix].un_id, |
1144 | suptr->un_ent[ix].un_num, |
1145 | suptr->un_ent[ix].un_adjval, |
1146 | semaptr->_sem_base[semnum].semval)); |
1147 | |
1148 | if (adjval < 0 && |
1149 | semaptr->_sem_base[semnum].semval < -adjval) |
1150 | semaptr->_sem_base[semnum].semval = 0; |
1151 | else |
1152 | semaptr->_sem_base[semnum].semval += adjval; |
1153 | |
1154 | cv_broadcast(&semcv[semid]); |
1155 | SEM_PRINTF(("semexit: back from wakeup\n" )); |
1156 | } |
1157 | } |
1158 | |
1159 | /* |
1160 | * Deallocate the undo vector. |
1161 | */ |
1162 | SEM_PRINTF(("removing vector\n" )); |
1163 | suptr->un_proc = NULL; |
1164 | *supptr = suptr->un_next; |
1165 | mutex_exit(&semlock); |
1166 | } |
1167 | |
1168 | /* |
1169 | * Sysctl initialization and nodes. |
1170 | */ |
1171 | |
1172 | static int |
1173 | sysctl_ipc_semmni(SYSCTLFN_ARGS) |
1174 | { |
1175 | int newsize, error; |
1176 | struct sysctlnode node; |
1177 | node = *rnode; |
1178 | node.sysctl_data = &newsize; |
1179 | |
1180 | newsize = seminfo.semmni; |
1181 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
1182 | if (error || newp == NULL) |
1183 | return error; |
1184 | |
1185 | return semrealloc(newsize, seminfo.semmns, seminfo.semmnu); |
1186 | } |
1187 | |
1188 | static int |
1189 | sysctl_ipc_semmns(SYSCTLFN_ARGS) |
1190 | { |
1191 | int newsize, error; |
1192 | struct sysctlnode node; |
1193 | node = *rnode; |
1194 | node.sysctl_data = &newsize; |
1195 | |
1196 | newsize = seminfo.semmns; |
1197 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
1198 | if (error || newp == NULL) |
1199 | return error; |
1200 | |
1201 | return semrealloc(seminfo.semmni, newsize, seminfo.semmnu); |
1202 | } |
1203 | |
1204 | static int |
1205 | sysctl_ipc_semmnu(SYSCTLFN_ARGS) |
1206 | { |
1207 | int newsize, error; |
1208 | struct sysctlnode node; |
1209 | node = *rnode; |
1210 | node.sysctl_data = &newsize; |
1211 | |
1212 | newsize = seminfo.semmnu; |
1213 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
1214 | if (error || newp == NULL) |
1215 | return error; |
1216 | |
1217 | return semrealloc(seminfo.semmni, seminfo.semmns, newsize); |
1218 | } |
1219 | |
1220 | SYSCTL_SETUP(sysctl_ipc_sem_setup, "sysctl kern.ipc subtree setup" ) |
1221 | { |
1222 | const struct sysctlnode *node = NULL; |
1223 | |
1224 | sysctl_createv(clog, 0, NULL, &node, |
1225 | CTLFLAG_PERMANENT, |
1226 | CTLTYPE_NODE, "ipc" , |
1227 | SYSCTL_DESCR("SysV IPC options" ), |
1228 | NULL, 0, NULL, 0, |
1229 | CTL_KERN, KERN_SYSVIPC, CTL_EOL); |
1230 | |
1231 | if (node == NULL) |
1232 | return; |
1233 | |
1234 | sysctl_createv(clog, 0, &node, NULL, |
1235 | CTLFLAG_PERMANENT | CTLFLAG_READWRITE, |
1236 | CTLTYPE_INT, "semmni" , |
1237 | SYSCTL_DESCR("Max number of number of semaphore identifiers" ), |
1238 | sysctl_ipc_semmni, 0, &seminfo.semmni, 0, |
1239 | CTL_CREATE, CTL_EOL); |
1240 | sysctl_createv(clog, 0, &node, NULL, |
1241 | CTLFLAG_PERMANENT | CTLFLAG_READWRITE, |
1242 | CTLTYPE_INT, "semmns" , |
1243 | SYSCTL_DESCR("Max number of number of semaphores in system" ), |
1244 | sysctl_ipc_semmns, 0, &seminfo.semmns, 0, |
1245 | CTL_CREATE, CTL_EOL); |
1246 | sysctl_createv(clog, 0, &node, NULL, |
1247 | CTLFLAG_PERMANENT | CTLFLAG_READWRITE, |
1248 | CTLTYPE_INT, "semmnu" , |
1249 | SYSCTL_DESCR("Max number of undo structures in system" ), |
1250 | sysctl_ipc_semmnu, 0, &seminfo.semmnu, 0, |
1251 | CTL_CREATE, CTL_EOL); |
1252 | } |
1253 | |