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282113ba CV |
1 | /* |
2 | * Implementation of SVID semaphores | |
3 | * | |
4 | * Author: Daniel Boulet | |
5 | * | |
6 | * This software is provided ``AS IS'' without any warranties of any kind. | |
7 | */ | |
8 | ||
9 | /* | |
10 | * This file is heavily changed to become part of Cygwin's cygserver. | |
11 | */ | |
12 | ||
13 | #ifdef __OUTSIDE_CYGWIN__ | |
14 | #include "woutsup.h" | |
15 | #include <sys/cygwin.h> | |
16 | #include <sys/cdefs.h> | |
17 | #ifndef __FBSDID | |
18 | #define __FBSDID(s) const char version[] = (s) | |
19 | #endif | |
c6ef5fb7 | 20 | __FBSDID("$FreeBSD: /repoman/r/ncvs/src/sys/kern/sysv_sem.c,v 1.70 2004/05/30 20:34:58 phk Exp $"); |
e3786825 | 21 | /* CV, 2006-01-09: Inspected upstream up to version 1.78. */ |
282113ba CV |
22 | |
23 | #define _KERNEL 1 | |
24 | #define __BSD_VISIBLE 1 | |
25 | #include <sys/types.h> | |
26 | #include <sys/ipc.h> | |
27 | ||
28 | #include <sys/param.h> | |
29 | #include <sys/sysproto.h> | |
30 | #include <sys/lock.h> | |
31 | #include <sys/sem.h> | |
32 | #include <sys/queue.h> | |
33 | #include <malloc.h> | |
34 | #include <errno.h> | |
35 | #include <time.h> | |
36 | #include "cygserver.h" | |
37 | #include "process.h" | |
38 | #include "cygserver_ipc.h" | |
dafef5e2 | 39 | #include <sys/smallprint.h> |
282113ba CV |
40 | |
41 | #ifdef __CYGWIN__ | |
42 | #define __semctl semctl | |
43 | #define __semctl_args semctl_args | |
44 | #define SEM_DEBUG | |
45 | #endif /* __CYGWIN__ */ | |
46 | ||
47 | #ifdef SEM_DEBUG | |
48 | #define DPRINTF(a) debug_printf a | |
49 | #else | |
50 | #define DPRINTF(a) | |
51 | #endif | |
52 | ||
53 | static int semvalid(int semid, struct semid_ds *semaptr); | |
54 | ||
55 | static struct sem_undo *semu_alloc(struct thread *td); | |
56 | static int semundo_adjust(struct thread *td, struct sem_undo **supptr, | |
57 | int semid, int semnum, int adjval); | |
dafef5e2 | 58 | static void semundo_clear(int semid, int semnum, struct thread *td); |
282113ba CV |
59 | |
60 | #ifndef _SYS_SYSPROTO_H_ | |
61 | struct __semctl_args; | |
62 | int __semctl(struct thread *td, struct __semctl_args *uap); | |
63 | struct semget_args; | |
64 | int semget(struct thread *td, struct semget_args *uap); | |
65 | struct semop_args; | |
66 | int semop(struct thread *td, struct semop_args *uap); | |
67 | #endif | |
68 | ||
69 | #ifndef __CYGWIN__ | |
70 | /* XXX casting to (sy_call_t *) is bogus, as usual. */ | |
71 | static sy_call_t *semcalls[] = { | |
72 | (sy_call_t *)__semctl, (sy_call_t *)semget, | |
73 | (sy_call_t *)semop | |
74 | }; | |
75 | #endif | |
76 | ||
77 | static struct mtx sem_mtx; /* semaphore global lock */ | |
78 | static int semtots = 0; | |
79 | static int semtot = 0; | |
80 | static struct semid_ds *sema; /* semaphore id pool */ | |
81 | static struct mtx *sema_mtx; /* semaphore id pool mutexes*/ | |
82 | static struct sem *sem; /* semaphore pool */ | |
43522735 | 83 | static SLIST_HEAD(, sem_undo) semu_list; /* list of active undo structures */ |
282113ba CV |
84 | static int *semu; /* undo structure pool */ |
85 | #ifndef __CYGWIN__ | |
86 | static eventhandler_tag semexit_tag; | |
87 | #endif /* __CYGWIN__ */ | |
88 | ||
89 | #define SEMUNDO_MTX sem_mtx | |
90 | #define SEMUNDO_LOCK() mtx_lock(&SEMUNDO_MTX); | |
91 | #define SEMUNDO_HOOKLOCK() _mtx_lock(&SEMUNDO_MTX, p->winpid, __FILE__, __LINE__); | |
92 | #define SEMUNDO_UNLOCK() mtx_unlock(&SEMUNDO_MTX); | |
dafef5e2 | 93 | #define SEMUNDO_LOCKASSERT(how,pid) mtx_assert(&SEMUNDO_MTX, (how), (pid)); |
282113ba CV |
94 | |
95 | struct sem { | |
96 | u_short semval; /* semaphore value */ | |
97 | pid_t sempid; /* pid of last operation */ | |
98 | u_short semncnt; /* # awaiting semval > cval */ | |
99 | u_short semzcnt; /* # awaiting semval = 0 */ | |
100 | }; | |
101 | ||
102 | /* | |
103 | * Undo structure (one per process) | |
104 | */ | |
105 | struct undo { | |
106 | short un_adjval; /* adjust on exit values */ | |
107 | short un_num; /* semaphore # */ | |
108 | int un_id; /* semid */ | |
109 | } un_ent[1]; /* undo entries */ | |
110 | ||
111 | struct sem_undo { | |
112 | SLIST_ENTRY(sem_undo) un_next; /* ptr to next active undo structure */ | |
dafef5e2 CV |
113 | #ifdef __CYGWIN__ |
114 | DWORD un_proc; /* owner of this structure */ | |
115 | #else | |
282113ba | 116 | struct proc *un_proc; /* owner of this structure */ |
dafef5e2 | 117 | #endif |
282113ba CV |
118 | short un_cnt; /* # of active entries */ |
119 | struct undo un_ent[1]; /* undo entries */ | |
120 | }; | |
121 | ||
122 | /* | |
123 | * Configuration parameters | |
124 | */ | |
125 | #ifndef SEMMNI | |
126 | #define SEMMNI 10 /* # of semaphore identifiers */ | |
127 | #endif | |
128 | #ifndef SEMMNS | |
129 | #define SEMMNS 60 /* # of semaphores in system */ | |
130 | #endif | |
131 | #ifndef SEMUME | |
132 | #define SEMUME 10 /* max # of undo entries per process */ | |
133 | #endif | |
134 | #ifndef SEMMNU | |
135 | #define SEMMNU 30 /* # of undo structures in system */ | |
136 | #endif | |
137 | ||
138 | /* shouldn't need tuning */ | |
139 | #ifndef SEMMAP | |
140 | #define SEMMAP 30 /* # of entries in semaphore map */ | |
141 | #endif | |
142 | #ifndef SEMMSL | |
143 | #define SEMMSL SEMMNS /* max # of semaphores per id */ | |
144 | #endif | |
145 | #ifndef SEMOPM | |
146 | #define SEMOPM 100 /* max # of operations per semop call */ | |
147 | #endif | |
148 | ||
149 | #ifndef SEMVMX | |
150 | #define SEMVMX 32767 /* semaphore maximum value */ | |
151 | #endif | |
152 | #ifndef SEMAEM | |
153 | #define SEMAEM 16384 /* adjust on exit max value */ | |
154 | #endif | |
155 | ||
52fa622a CV |
156 | #ifdef __CYGWIN__ |
157 | /* gcc 3.4 defines a new offsetof which is different for C++. Since this | |
158 | file is just a derived plain-C file, we need to revert to the plain-C | |
159 | definition of offsetof. */ | |
160 | #ifdef offsetof | |
161 | #undef offsetof | |
162 | #endif | |
163 | #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) | |
164 | #endif /* __CYGWIN__ */ | |
282113ba CV |
165 | /* |
166 | * Due to the way semaphore memory is allocated, we have to ensure that | |
167 | * SEMUSZ is properly aligned. | |
168 | */ | |
169 | ||
170 | #define SEM_ALIGN(bytes) (((bytes) + (sizeof(long) - 1)) & ~(sizeof(long) - 1)) | |
171 | ||
172 | /* actual size of an undo structure */ | |
173 | #define SEMUSZ SEM_ALIGN(offsetof(struct sem_undo, un_ent[SEMUME])) | |
174 | ||
175 | /* | |
176 | * Macro to find a particular sem_undo vector | |
177 | */ | |
178 | #define SEMU(ix) \ | |
179 | ((struct sem_undo *)(((intptr_t)semu)+ix * seminfo.semusz)) | |
180 | ||
181 | /* | |
182 | * semaphore info struct | |
183 | */ | |
184 | struct seminfo seminfo = { | |
185 | SEMMNI, /* # of semaphore identifiers */ | |
186 | SEMMNS, /* # of semaphores in system */ | |
187 | SEMMSL, /* max # of semaphores per id */ | |
188 | SEMOPM, /* max # of operations per semop call */ | |
189 | SEMMNU, /* # of undo structures in system */ | |
190 | SEMUME, /* max # of undo entries per process */ | |
191 | SEMVMX, /* semaphore maximum value */ | |
192 | SEMAEM, /* adjust on exit max value */ | |
193 | SEMMAP, /* # of entries in semaphore map */ | |
194 | SEMUSZ /* size in bytes of undo structure */ | |
195 | }; | |
196 | ||
197 | #ifndef __CYGWIN__ | |
198 | SYSCTL_DECL(_kern_ipc); | |
199 | SYSCTL_INT(_kern_ipc, OID_AUTO, semmap, CTLFLAG_RW, &seminfo.semmap, 0, ""); | |
200 | SYSCTL_INT(_kern_ipc, OID_AUTO, semmni, CTLFLAG_RDTUN, &seminfo.semmni, 0, ""); | |
201 | SYSCTL_INT(_kern_ipc, OID_AUTO, semmns, CTLFLAG_RDTUN, &seminfo.semmns, 0, ""); | |
202 | SYSCTL_INT(_kern_ipc, OID_AUTO, semmnu, CTLFLAG_RDTUN, &seminfo.semmnu, 0, ""); | |
203 | SYSCTL_INT(_kern_ipc, OID_AUTO, semmsl, CTLFLAG_RW, &seminfo.semmsl, 0, ""); | |
204 | SYSCTL_INT(_kern_ipc, OID_AUTO, semopm, CTLFLAG_RDTUN, &seminfo.semopm, 0, ""); | |
205 | SYSCTL_INT(_kern_ipc, OID_AUTO, semume, CTLFLAG_RDTUN, &seminfo.semume, 0, ""); | |
206 | SYSCTL_INT(_kern_ipc, OID_AUTO, semusz, CTLFLAG_RDTUN, &seminfo.semusz, 0, ""); | |
207 | SYSCTL_INT(_kern_ipc, OID_AUTO, semvmx, CTLFLAG_RW, &seminfo.semvmx, 0, ""); | |
208 | SYSCTL_INT(_kern_ipc, OID_AUTO, semaem, CTLFLAG_RW, &seminfo.semaem, 0, ""); | |
209 | SYSCTL_PROC(_kern_ipc, OID_AUTO, sema, CTLFLAG_RD, | |
210 | NULL, 0, sysctl_sema, "", ""); | |
211 | #endif /* __CYGWIN__ */ | |
212 | ||
213 | void | |
214 | seminit(void) | |
215 | { | |
216 | int i; | |
217 | ||
218 | TUNABLE_INT_FETCH("kern.ipc.semmap", &seminfo.semmap); | |
219 | TUNABLE_INT_FETCH("kern.ipc.semmni", &seminfo.semmni); | |
220 | TUNABLE_INT_FETCH("kern.ipc.semmns", &seminfo.semmns); | |
221 | TUNABLE_INT_FETCH("kern.ipc.semmnu", &seminfo.semmnu); | |
222 | TUNABLE_INT_FETCH("kern.ipc.semmsl", &seminfo.semmsl); | |
223 | TUNABLE_INT_FETCH("kern.ipc.semopm", &seminfo.semopm); | |
224 | TUNABLE_INT_FETCH("kern.ipc.semume", &seminfo.semume); | |
225 | TUNABLE_INT_FETCH("kern.ipc.semusz", &seminfo.semusz); | |
226 | TUNABLE_INT_FETCH("kern.ipc.semvmx", &seminfo.semvmx); | |
227 | TUNABLE_INT_FETCH("kern.ipc.semaem", &seminfo.semaem); | |
228 | ||
229 | #ifdef __CYGWIN__ | |
230 | /* It's too dangerous a setting to leave it alone. | |
231 | Keep that clean here. */ | |
232 | seminfo.semusz = SEM_ALIGN(offsetof(struct sem_undo, | |
233 | un_ent[seminfo.semume])); | |
234 | #endif /* __CYGWIN__ */ | |
235 | ||
236 | sem = (struct sem *) sys_malloc(sizeof(struct sem) * seminfo.semmns, M_SEM, M_WAITOK); | |
237 | sema = (struct semid_ds *) sys_malloc(sizeof(struct semid_ds) * seminfo.semmni, M_SEM, | |
238 | M_WAITOK); | |
239 | sema_mtx = (struct mtx *) sys_malloc(sizeof(struct mtx) * seminfo.semmni, M_SEM, | |
240 | M_WAITOK | M_ZERO); | |
241 | semu = (int *) sys_malloc(seminfo.semmnu * seminfo.semusz, M_SEM, M_WAITOK); | |
242 | ||
243 | for (i = 0; i < seminfo.semmni; i++) { | |
244 | sema[i].sem_base = 0; | |
245 | sema[i].sem_perm.mode = 0; | |
1d88f8ce | 246 | sema[i].sem_perm.seq = 0; |
282113ba CV |
247 | } |
248 | for (i = 0; i < seminfo.semmni; i++) | |
dafef5e2 CV |
249 | { |
250 | char *buf = (char *)malloc (16); | |
251 | __small_sprintf (buf, "semid[%d]", i); | |
252 | mtx_init(&sema_mtx[i], buf, NULL, MTX_DEF); | |
253 | } | |
282113ba CV |
254 | for (i = 0; i < seminfo.semmnu; i++) { |
255 | struct sem_undo *suptr = SEMU(i); | |
dafef5e2 CV |
256 | #ifdef __CYGWIN__ |
257 | suptr->un_proc = 0; | |
258 | #else | |
282113ba | 259 | suptr->un_proc = NULL; |
dafef5e2 | 260 | #endif |
282113ba CV |
261 | } |
262 | SLIST_INIT(&semu_list); | |
263 | mtx_init(&sem_mtx, "sem", NULL, MTX_DEF); | |
264 | #ifndef __CYGWIN__ | |
265 | semexit_tag = EVENTHANDLER_REGISTER(process_exit, semexit_myhook, NULL, | |
266 | EVENTHANDLER_PRI_ANY); | |
267 | #endif /* __CYGWIN__ */ | |
268 | } | |
269 | ||
270 | int | |
271 | semunload(void) | |
272 | { | |
273 | #ifndef __CYGWIN__ /* Would result in being unable to shutdown the | |
274 | server gracefully. */ | |
275 | if (semtot != 0) | |
276 | return (EBUSY); | |
277 | ||
278 | EVENTHANDLER_DEREGISTER(process_exit, semexit_tag); | |
279 | #endif /* __CYGWIN__ */ | |
280 | sys_free(sem, M_SEM); | |
281 | sys_free(sema, M_SEM); | |
282 | sys_free(semu, M_SEM); | |
283 | for (int i = 0; i < seminfo.semmni; i++) | |
284 | mtx_destroy(&sema_mtx[i]); | |
285 | mtx_destroy(&sem_mtx); | |
286 | return (0); | |
287 | } | |
288 | ||
289 | #ifndef __CYGWIN__ | |
290 | static int | |
291 | sysvsem_modload(struct module *module, int cmd, void *arg) | |
292 | { | |
293 | int error = 0; | |
294 | ||
295 | switch (cmd) { | |
296 | case MOD_LOAD: | |
297 | seminit(); | |
298 | break; | |
299 | case MOD_UNLOAD: | |
300 | error = semunload(); | |
301 | break; | |
302 | case MOD_SHUTDOWN: | |
303 | break; | |
304 | default: | |
305 | error = EINVAL; | |
306 | break; | |
307 | } | |
308 | return (error); | |
309 | } | |
310 | ||
311 | static moduledata_t sysvsem_mod = { | |
312 | "sysvsem", | |
313 | &sysvsem_modload, | |
314 | NULL | |
315 | }; | |
316 | ||
317 | SYSCALL_MODULE_HELPER(semsys); | |
318 | SYSCALL_MODULE_HELPER(__semctl); | |
319 | SYSCALL_MODULE_HELPER(semget); | |
320 | SYSCALL_MODULE_HELPER(semop); | |
321 | ||
322 | DECLARE_MODULE(sysvsem, sysvsem_mod, | |
323 | SI_SUB_SYSV_SEM, SI_ORDER_FIRST); | |
324 | MODULE_VERSION(sysvsem, 1); | |
325 | ||
326 | /* | |
327 | * Entry point for all SEM calls | |
328 | * | |
329 | * MPSAFE | |
330 | */ | |
331 | int | |
332 | semsys(td, uap) | |
333 | struct thread *td; | |
334 | /* XXX actually varargs. */ | |
335 | struct semsys_args /* { | |
336 | int which; | |
337 | int a2; | |
338 | int a3; | |
339 | int a4; | |
340 | int a5; | |
341 | } */ *uap; | |
342 | { | |
343 | int error; | |
344 | ||
345 | if (!jail_sysvipc_allowed && jailed(td->td_ucred)) | |
346 | return (ENOSYS); | |
347 | if (uap->which < 0 || | |
348 | uap->which >= sizeof(semcalls)/sizeof(semcalls[0])) | |
349 | return (EINVAL); | |
350 | error = (*semcalls[uap->which])(td, &uap->a2); | |
351 | return (error); | |
352 | } | |
353 | #endif /* __CYGWIN__ */ | |
354 | ||
355 | /* | |
356 | * Allocate a new sem_undo structure for a process | |
357 | * (returns ptr to structure or NULL if no more room) | |
358 | */ | |
359 | ||
360 | static struct sem_undo * | |
361 | semu_alloc(struct thread *td) | |
362 | { | |
363 | int i; | |
364 | struct sem_undo *suptr; | |
365 | struct sem_undo **supptr; | |
366 | int attempt; | |
367 | ||
dafef5e2 | 368 | SEMUNDO_LOCKASSERT(MA_OWNED, td->td_proc->winpid); |
282113ba CV |
369 | /* |
370 | * Try twice to allocate something. | |
371 | * (we'll purge an empty structure after the first pass so | |
372 | * two passes are always enough) | |
373 | */ | |
374 | ||
375 | for (attempt = 0; attempt < 2; attempt++) { | |
376 | /* | |
377 | * Look for a free structure. | |
378 | * Fill it in and return it if we find one. | |
379 | */ | |
380 | ||
381 | for (i = 0; i < seminfo.semmnu; i++) { | |
382 | suptr = SEMU(i); | |
dafef5e2 CV |
383 | #ifdef __CYGWIN__ |
384 | if (suptr->un_proc == 0) { | |
385 | #else | |
282113ba | 386 | if (suptr->un_proc == NULL) { |
dafef5e2 | 387 | #endif |
282113ba CV |
388 | SLIST_INSERT_HEAD(&semu_list, suptr, un_next); |
389 | suptr->un_cnt = 0; | |
dafef5e2 | 390 | suptr->un_proc = td->td_proc->winpid; |
282113ba CV |
391 | return(suptr); |
392 | } | |
393 | } | |
394 | ||
395 | /* | |
396 | * We didn't find a free one, if this is the first attempt | |
397 | * then try to free a structure. | |
398 | */ | |
399 | ||
400 | if (attempt == 0) { | |
401 | /* All the structures are in use - try to free one */ | |
402 | int did_something = 0; | |
403 | ||
404 | SLIST_FOREACH_PREVPTR(suptr, supptr, &semu_list, | |
405 | un_next) { | |
406 | if (suptr->un_cnt == 0) { | |
dafef5e2 CV |
407 | #ifdef __CYGWIN__ |
408 | suptr->un_proc = 0; | |
409 | #else | |
282113ba | 410 | suptr->un_proc = NULL; |
dafef5e2 | 411 | #endif |
282113ba CV |
412 | did_something = 1; |
413 | *supptr = SLIST_NEXT(suptr, un_next); | |
414 | break; | |
415 | } | |
416 | } | |
417 | ||
418 | /* If we didn't free anything then just give-up */ | |
419 | if (!did_something) | |
420 | return(NULL); | |
421 | } else { | |
422 | /* | |
423 | * The second pass failed even though we freed | |
424 | * something after the first pass! | |
425 | * This is IMPOSSIBLE! | |
426 | */ | |
427 | panic("semu_alloc - second attempt failed"); | |
428 | } | |
429 | } | |
430 | return (NULL); | |
431 | } | |
432 | ||
433 | /* | |
434 | * Adjust a particular entry for a particular proc | |
435 | */ | |
436 | ||
437 | static int | |
438 | semundo_adjust(struct thread *td, struct sem_undo **supptr, int semid, | |
439 | int semnum, int adjval) | |
440 | { | |
441 | struct proc *p = td->td_proc; | |
442 | struct sem_undo *suptr; | |
443 | struct undo *sunptr; | |
444 | int i; | |
445 | ||
dafef5e2 | 446 | SEMUNDO_LOCKASSERT(MA_OWNED, td->td_proc->winpid); |
282113ba CV |
447 | /* Look for and remember the sem_undo if the caller doesn't provide |
448 | it */ | |
449 | ||
450 | suptr = *supptr; | |
451 | if (suptr == NULL) { | |
452 | SLIST_FOREACH(suptr, &semu_list, un_next) { | |
ddb1a4c1 | 453 | #ifdef __CYGWIN__ |
dafef5e2 | 454 | if (suptr->un_proc == p->winpid) { |
ddb1a4c1 | 455 | #else |
282113ba | 456 | if (suptr->un_proc == p) { |
ddb1a4c1 | 457 | #endif |
282113ba CV |
458 | *supptr = suptr; |
459 | break; | |
460 | } | |
461 | } | |
462 | if (suptr == NULL) { | |
463 | if (adjval == 0) | |
464 | return(0); | |
465 | suptr = semu_alloc(td); | |
466 | if (suptr == NULL) | |
467 | return(ENOSPC); | |
468 | *supptr = suptr; | |
469 | } | |
470 | } | |
471 | ||
472 | /* | |
473 | * Look for the requested entry and adjust it (delete if adjval becomes | |
474 | * 0). | |
475 | */ | |
476 | sunptr = &suptr->un_ent[0]; | |
477 | for (i = 0; i < suptr->un_cnt; i++, sunptr++) { | |
478 | if (sunptr->un_id != semid || sunptr->un_num != semnum) | |
479 | continue; | |
480 | if (adjval != 0) { | |
481 | adjval += sunptr->un_adjval; | |
482 | if (adjval > seminfo.semaem || adjval < -seminfo.semaem) | |
483 | return (ERANGE); | |
484 | } | |
485 | sunptr->un_adjval = adjval; | |
486 | if (sunptr->un_adjval == 0) { | |
487 | suptr->un_cnt--; | |
488 | if (i < suptr->un_cnt) | |
489 | suptr->un_ent[i] = | |
490 | suptr->un_ent[suptr->un_cnt]; | |
491 | } | |
492 | return(0); | |
493 | } | |
494 | ||
495 | /* Didn't find the right entry - create it */ | |
496 | if (adjval == 0) | |
497 | return(0); | |
498 | if (adjval > seminfo.semaem || adjval < -seminfo.semaem) | |
499 | return (ERANGE); | |
500 | if (suptr->un_cnt != seminfo.semume) { | |
501 | sunptr = &suptr->un_ent[suptr->un_cnt]; | |
502 | suptr->un_cnt++; | |
503 | sunptr->un_adjval = adjval; | |
504 | sunptr->un_id = semid; sunptr->un_num = semnum; | |
505 | } else | |
506 | return(EINVAL); | |
507 | return(0); | |
508 | } | |
509 | ||
510 | static void | |
dafef5e2 | 511 | semundo_clear(int semid, int semnum, struct thread *td) |
282113ba CV |
512 | { |
513 | struct sem_undo *suptr; | |
514 | ||
dafef5e2 | 515 | SEMUNDO_LOCKASSERT(MA_OWNED, td->td_proc->winpid); |
282113ba CV |
516 | SLIST_FOREACH(suptr, &semu_list, un_next) { |
517 | struct undo *sunptr = &suptr->un_ent[0]; | |
518 | int i = 0; | |
519 | ||
520 | while (i < suptr->un_cnt) { | |
521 | if (sunptr->un_id == semid) { | |
522 | if (semnum == -1 || sunptr->un_num == semnum) { | |
523 | suptr->un_cnt--; | |
524 | if (i < suptr->un_cnt) { | |
525 | suptr->un_ent[i] = | |
526 | suptr->un_ent[suptr->un_cnt]; | |
527 | continue; | |
528 | } | |
529 | } | |
530 | if (semnum != -1) | |
531 | break; | |
532 | } | |
533 | i++, sunptr++; | |
534 | } | |
535 | } | |
536 | } | |
537 | ||
538 | static int | |
539 | semvalid(int semid, struct semid_ds *semaptr) | |
540 | { | |
541 | ||
542 | return ((semaptr->sem_perm.mode & SEM_ALLOC) == 0 || | |
543 | semaptr->sem_perm.seq != IPCID_TO_SEQ(semid) ? EINVAL : 0); | |
544 | } | |
545 | ||
546 | /* | |
547 | * Note that the user-mode half of this passes a union, not a pointer | |
548 | */ | |
549 | #ifndef _SYS_SYSPROTO_H_ | |
550 | struct __semctl_args { | |
551 | int semid; | |
552 | int semnum; | |
553 | int cmd; | |
554 | union semun *arg; | |
555 | }; | |
556 | #endif | |
557 | ||
558 | /* | |
559 | * MPSAFE | |
560 | */ | |
561 | int | |
562 | __semctl(struct thread *td, struct __semctl_args *uap) | |
563 | { | |
564 | int semid = uap->semid; | |
565 | int semnum = uap->semnum; | |
566 | int cmd = uap->cmd; | |
567 | u_short *array; | |
568 | union semun *arg = uap->arg; | |
569 | union semun real_arg; | |
570 | #ifndef __CYGWIN__ | |
571 | struct ucred *cred = td->td_ucred; | |
572 | #endif | |
573 | int i, rval, error; | |
574 | struct semid_ds sbuf; | |
575 | struct semid_ds *semaptr; | |
576 | struct mtx *sema_mtxp; | |
577 | u_short usval, count; | |
578 | ||
579 | DPRINTF(("call to semctl(%d, %d, %d, 0x%x)\n", | |
580 | semid, semnum, cmd, arg)); | |
581 | if (!jail_sysvipc_allowed && jailed(td->td_ucred)) | |
582 | return (ENOSYS); | |
583 | ||
584 | array = NULL; | |
585 | ||
586 | switch(cmd) { | |
587 | #ifdef __CYGWIN__ | |
588 | case IPC_INFO: | |
589 | if ((error = copyin(arg, &real_arg, sizeof(real_arg))) != 0) | |
590 | return (error); | |
591 | if (!semid) { | |
592 | error = copyout(&seminfo, real_arg.buf, | |
593 | sizeof(struct seminfo)); | |
594 | td->td_retval[0] = error ? -1 : 0; | |
595 | return (error); | |
596 | } | |
597 | if (semid > seminfo.semmni) | |
598 | semid = seminfo.semmni; | |
599 | error = copyout(sema, real_arg.buf, | |
600 | semid * sizeof(struct semid_ds)); | |
601 | td->td_retval[0] = error ? -1 : 0; | |
602 | return (error); | |
603 | case SEM_INFO: | |
604 | if (!(error = copyin(arg, &real_arg, sizeof(real_arg)))) { | |
605 | struct sem_info sem_info; | |
606 | sem_info.sem_ids = semtots; | |
607 | sem_info.sem_num = semtot; | |
608 | error = copyout(&sem_info, real_arg.buf, | |
609 | sizeof(struct sem_info)); | |
610 | } | |
611 | td->td_retval[0] = error ? -1 : 0; | |
612 | return (error); | |
613 | ||
614 | #endif /* __CYGWIN__ */ | |
615 | case SEM_STAT: | |
616 | if (semid < 0 || semid >= seminfo.semmni) | |
617 | return (EINVAL); | |
618 | if ((error = copyin(arg, &real_arg, sizeof(real_arg))) != 0) | |
619 | return (error); | |
620 | semaptr = &sema[semid]; | |
621 | sema_mtxp = &sema_mtx[semid]; | |
622 | mtx_lock(sema_mtxp); | |
623 | if ((semaptr->sem_perm.mode & SEM_ALLOC) == 0) { | |
624 | error = EINVAL; | |
625 | goto done2; | |
626 | } | |
627 | if ((error = ipcperm(td, &semaptr->sem_perm, IPC_R))) | |
628 | goto done2; | |
629 | mtx_unlock(sema_mtxp); | |
630 | error = copyout(semaptr, real_arg.buf, sizeof(struct semid_ds)); | |
631 | rval = IXSEQ_TO_IPCID(semid,semaptr->sem_perm); | |
632 | if (error == 0) | |
633 | td->td_retval[0] = rval; | |
634 | return (error); | |
635 | } | |
636 | ||
637 | semid = IPCID_TO_IX(semid); | |
638 | if (semid < 0 || semid >= seminfo.semmni) | |
639 | return (EINVAL); | |
640 | ||
641 | semaptr = &sema[semid]; | |
642 | sema_mtxp = &sema_mtx[semid]; | |
643 | ||
644 | error = 0; | |
645 | rval = 0; | |
646 | ||
647 | switch (cmd) { | |
648 | case IPC_RMID: | |
649 | mtx_lock(sema_mtxp); | |
650 | if ((error = semvalid(uap->semid, semaptr)) != 0) | |
651 | goto done2; | |
652 | if ((error = ipcperm(td, &semaptr->sem_perm, IPC_M))) | |
653 | goto done2; | |
654 | #ifdef __CYGWIN__ | |
655 | semaptr->sem_perm.cuid = td->ipcblk->uid; | |
656 | semaptr->sem_perm.uid = td->ipcblk->uid; | |
657 | #else | |
658 | semaptr->sem_perm.cuid = cred->cr_uid; | |
659 | semaptr->sem_perm.uid = cred->cr_uid; | |
660 | #endif | |
661 | semtot -= semaptr->sem_nsems; | |
662 | semtots--; | |
663 | for (i = semaptr->sem_base - sem; i < semtot; i++) | |
664 | sem[i] = sem[i + semaptr->sem_nsems]; | |
665 | for (i = 0; i < seminfo.semmni; i++) { | |
666 | if ((sema[i].sem_perm.mode & SEM_ALLOC) && | |
667 | sema[i].sem_base > semaptr->sem_base) | |
668 | sema[i].sem_base -= semaptr->sem_nsems; | |
669 | } | |
670 | semaptr->sem_perm.mode = 0; | |
671 | SEMUNDO_LOCK(); | |
dafef5e2 | 672 | semundo_clear(semid, -1, td); |
282113ba CV |
673 | SEMUNDO_UNLOCK(); |
674 | wakeup(semaptr); | |
675 | break; | |
676 | ||
677 | case IPC_SET: | |
678 | if ((error = copyin(arg, &real_arg, sizeof(real_arg))) != 0) | |
679 | goto done2; | |
680 | if ((error = copyin(real_arg.buf, &sbuf, sizeof(sbuf))) != 0) | |
681 | goto done2; | |
682 | mtx_lock(sema_mtxp); | |
683 | if ((error = semvalid(uap->semid, semaptr)) != 0) | |
684 | goto done2; | |
685 | if ((error = ipcperm(td, &semaptr->sem_perm, IPC_M))) | |
686 | goto done2; | |
687 | semaptr->sem_perm.uid = sbuf.sem_perm.uid; | |
688 | semaptr->sem_perm.gid = sbuf.sem_perm.gid; | |
689 | semaptr->sem_perm.mode = (semaptr->sem_perm.mode & ~0777) | | |
690 | (sbuf.sem_perm.mode & 0777); | |
691 | semaptr->sem_ctime = time (NULL); | |
692 | break; | |
693 | ||
694 | case IPC_STAT: | |
695 | if ((error = copyin(arg, &real_arg, sizeof(real_arg))) != 0) | |
696 | goto done2; | |
697 | mtx_lock(sema_mtxp); | |
698 | if ((error = semvalid(uap->semid, semaptr)) != 0) | |
699 | goto done2; | |
700 | if ((error = ipcperm(td, &semaptr->sem_perm, IPC_R))) | |
701 | goto done2; | |
702 | sbuf = *semaptr; | |
703 | mtx_unlock(sema_mtxp); | |
704 | error = copyout(semaptr, real_arg.buf, | |
705 | sizeof(struct semid_ds)); | |
706 | break; | |
707 | ||
708 | case GETNCNT: | |
709 | mtx_lock(sema_mtxp); | |
710 | if ((error = semvalid(uap->semid, semaptr)) != 0) | |
711 | goto done2; | |
712 | if ((error = ipcperm(td, &semaptr->sem_perm, IPC_R))) | |
713 | goto done2; | |
714 | if (semnum < 0 || semnum >= semaptr->sem_nsems) { | |
715 | error = EINVAL; | |
716 | goto done2; | |
717 | } | |
718 | rval = semaptr->sem_base[semnum].semncnt; | |
719 | break; | |
720 | ||
721 | case GETPID: | |
722 | mtx_lock(sema_mtxp); | |
723 | if ((error = semvalid(uap->semid, semaptr)) != 0) | |
724 | goto done2; | |
725 | if ((error = ipcperm(td, &semaptr->sem_perm, IPC_R))) | |
726 | goto done2; | |
727 | if (semnum < 0 || semnum >= semaptr->sem_nsems) { | |
728 | error = EINVAL; | |
729 | goto done2; | |
730 | } | |
731 | rval = semaptr->sem_base[semnum].sempid; | |
732 | break; | |
733 | ||
734 | case GETVAL: | |
735 | mtx_lock(sema_mtxp); | |
736 | if ((error = semvalid(uap->semid, semaptr)) != 0) | |
737 | goto done2; | |
738 | if ((error = ipcperm(td, &semaptr->sem_perm, IPC_R))) | |
739 | goto done2; | |
740 | if (semnum < 0 || semnum >= semaptr->sem_nsems) { | |
741 | error = EINVAL; | |
742 | goto done2; | |
743 | } | |
744 | rval = semaptr->sem_base[semnum].semval; | |
745 | break; | |
746 | ||
747 | case GETALL: | |
748 | if ((error = copyin(arg, &real_arg, sizeof(real_arg))) != 0) | |
749 | goto done2; | |
750 | array = (u_short *) sys_malloc(sizeof(*array) * semaptr->sem_nsems, M_TEMP, | |
751 | M_WAITOK); | |
752 | mtx_lock(sema_mtxp); | |
753 | if ((error = semvalid(uap->semid, semaptr)) != 0) | |
754 | goto done2; | |
755 | if ((error = ipcperm(td, &semaptr->sem_perm, IPC_R))) | |
756 | goto done2; | |
757 | for (i = 0; i < semaptr->sem_nsems; i++) | |
758 | array[i] = semaptr->sem_base[i].semval; | |
759 | mtx_unlock(sema_mtxp); | |
760 | error = copyout(array, real_arg.array, | |
761 | i * sizeof(real_arg.array[0])); | |
762 | break; | |
763 | ||
764 | case GETZCNT: | |
765 | mtx_lock(sema_mtxp); | |
766 | if ((error = semvalid(uap->semid, semaptr)) != 0) | |
767 | goto done2; | |
768 | if ((error = ipcperm(td, &semaptr->sem_perm, IPC_R))) | |
769 | goto done2; | |
770 | if (semnum < 0 || semnum >= semaptr->sem_nsems) { | |
771 | error = EINVAL; | |
772 | goto done2; | |
773 | } | |
774 | rval = semaptr->sem_base[semnum].semzcnt; | |
775 | break; | |
776 | ||
777 | case SETVAL: | |
778 | if ((error = copyin(arg, &real_arg, sizeof(real_arg))) != 0) | |
779 | goto done2; | |
780 | mtx_lock(sema_mtxp); | |
781 | if ((error = semvalid(uap->semid, semaptr)) != 0) | |
782 | goto done2; | |
783 | if ((error = ipcperm(td, &semaptr->sem_perm, IPC_W))) | |
784 | goto done2; | |
785 | if (semnum < 0 || semnum >= semaptr->sem_nsems) { | |
786 | error = EINVAL; | |
787 | goto done2; | |
788 | } | |
789 | if (real_arg.val < 0 || real_arg.val > seminfo.semvmx) { | |
790 | error = ERANGE; | |
791 | goto done2; | |
792 | } | |
793 | semaptr->sem_base[semnum].semval = real_arg.val; | |
794 | SEMUNDO_LOCK(); | |
dafef5e2 | 795 | semundo_clear(semid, semnum, td); |
282113ba CV |
796 | SEMUNDO_UNLOCK(); |
797 | wakeup(semaptr); | |
798 | break; | |
799 | ||
800 | case SETALL: | |
801 | mtx_lock(sema_mtxp); | |
802 | raced: | |
803 | if ((error = semvalid(uap->semid, semaptr)) != 0) | |
804 | goto done2; | |
805 | count = semaptr->sem_nsems; | |
806 | mtx_unlock(sema_mtxp); | |
807 | if ((error = copyin(arg, &real_arg, sizeof(real_arg))) != 0) | |
808 | goto done2; | |
809 | array = (u_short *) sys_malloc(sizeof(*array) * count, M_TEMP, M_WAITOK); | |
e3786825 | 810 | error = copyin(real_arg.array, array, count * sizeof(*array)); |
282113ba CV |
811 | if (error) |
812 | break; | |
813 | mtx_lock(sema_mtxp); | |
814 | if ((error = semvalid(uap->semid, semaptr)) != 0) | |
815 | goto done2; | |
816 | /* we could have raced? */ | |
817 | if (count != semaptr->sem_nsems) { | |
818 | sys_free(array, M_TEMP); | |
819 | array = NULL; | |
820 | goto raced; | |
821 | } | |
822 | if ((error = ipcperm(td, &semaptr->sem_perm, IPC_W))) | |
823 | goto done2; | |
824 | for (i = 0; i < semaptr->sem_nsems; i++) { | |
825 | usval = array[i]; | |
826 | if (usval > seminfo.semvmx) { | |
827 | error = ERANGE; | |
828 | break; | |
829 | } | |
830 | semaptr->sem_base[i].semval = usval; | |
831 | } | |
832 | SEMUNDO_LOCK(); | |
dafef5e2 | 833 | semundo_clear(semid, -1, td); |
282113ba CV |
834 | SEMUNDO_UNLOCK(); |
835 | wakeup(semaptr); | |
836 | break; | |
837 | ||
838 | default: | |
839 | error = EINVAL; | |
840 | break; | |
841 | } | |
842 | ||
843 | if (error == 0) | |
844 | td->td_retval[0] = rval; | |
845 | done2: | |
dafef5e2 | 846 | if (mtx_owned(sema_mtxp, td->td_proc->winpid)) |
282113ba CV |
847 | mtx_unlock(sema_mtxp); |
848 | if (array != NULL) | |
849 | sys_free(array, M_TEMP); | |
850 | return(error); | |
851 | } | |
852 | ||
853 | #ifndef _SYS_SYSPROTO_H_ | |
854 | struct semget_args { | |
855 | key_t key; | |
856 | int nsems; | |
857 | int semflg; | |
858 | }; | |
859 | #endif | |
860 | ||
861 | /* | |
862 | * MPSAFE | |
863 | */ | |
864 | int | |
865 | semget(struct thread *td, struct semget_args *uap) | |
866 | { | |
867 | int semid, error = 0; | |
868 | key_t key = uap->key; | |
869 | int nsems = uap->nsems; | |
870 | int semflg = uap->semflg; | |
871 | #ifndef __CYGWIN__ | |
872 | struct ucred *cred = td->td_ucred; | |
873 | #endif | |
874 | ||
dafef5e2 | 875 | DPRINTF(("semget(0x%X, %d, 0%o)\n", key, nsems, semflg)); |
282113ba CV |
876 | if (!jail_sysvipc_allowed && jailed(td->td_ucred)) |
877 | return (ENOSYS); | |
878 | ||
879 | mtx_lock(&Giant); | |
880 | if (key != IPC_PRIVATE) { | |
881 | for (semid = 0; semid < seminfo.semmni; semid++) { | |
882 | if ((sema[semid].sem_perm.mode & SEM_ALLOC) && | |
883 | sema[semid].sem_perm.key == key) | |
884 | break; | |
885 | } | |
886 | if (semid < seminfo.semmni) { | |
887 | DPRINTF(("found public key\n")); | |
888 | if ((error = ipcperm(td, &sema[semid].sem_perm, | |
889 | semflg & 0700))) { | |
890 | goto done2; | |
891 | } | |
892 | if (nsems > 0 && sema[semid].sem_nsems < nsems) { | |
893 | DPRINTF(("too small\n")); | |
894 | error = EINVAL; | |
895 | goto done2; | |
896 | } | |
897 | if ((semflg & IPC_CREAT) && (semflg & IPC_EXCL)) { | |
898 | DPRINTF(("not exclusive\n")); | |
899 | error = EEXIST; | |
900 | goto done2; | |
901 | } | |
902 | goto found; | |
903 | } | |
904 | } | |
905 | ||
906 | DPRINTF(("need to allocate the semid_ds\n")); | |
907 | if (key == IPC_PRIVATE || (semflg & IPC_CREAT)) { | |
908 | if (nsems <= 0 || nsems > seminfo.semmsl) { | |
909 | DPRINTF(("nsems out of range (0<%d<=%d)\n", nsems, | |
910 | seminfo.semmsl)); | |
911 | error = EINVAL; | |
912 | goto done2; | |
913 | } | |
914 | if (nsems > seminfo.semmns - semtot) { | |
915 | DPRINTF(( | |
916 | "not enough semaphores left (need %d, got %d)\n", | |
917 | nsems, seminfo.semmns - semtot)); | |
918 | error = ENOSPC; | |
919 | goto done2; | |
920 | } | |
921 | for (semid = 0; semid < seminfo.semmni; semid++) { | |
922 | if ((sema[semid].sem_perm.mode & SEM_ALLOC) == 0) | |
923 | break; | |
924 | } | |
925 | if (semid == seminfo.semmni) { | |
926 | DPRINTF(("no more semid_ds's available\n")); | |
927 | error = ENOSPC; | |
928 | goto done2; | |
929 | } | |
930 | DPRINTF(("semid %d is available\n", semid)); | |
931 | sema[semid].sem_perm.key = key; | |
932 | #ifdef __CYGWIN__ | |
933 | sema[semid].sem_perm.cuid = td->ipcblk->uid; | |
934 | sema[semid].sem_perm.uid = td->ipcblk->uid; | |
935 | sema[semid].sem_perm.cgid = td->ipcblk->gid; | |
936 | sema[semid].sem_perm.gid = td->ipcblk->gid; | |
937 | #else | |
938 | sema[semid].sem_perm.cuid = cred->cr_uid; | |
939 | sema[semid].sem_perm.uid = cred->cr_uid; | |
940 | sema[semid].sem_perm.cgid = cred->cr_gid; | |
941 | sema[semid].sem_perm.gid = cred->cr_gid; | |
942 | #endif | |
943 | sema[semid].sem_perm.mode = (semflg & 0777) | SEM_ALLOC; | |
944 | sema[semid].sem_perm.seq = | |
945 | (sema[semid].sem_perm.seq + 1) & 0x7fff; | |
946 | sema[semid].sem_nsems = nsems; | |
947 | sema[semid].sem_otime = 0; | |
948 | sema[semid].sem_ctime = time (NULL); | |
949 | sema[semid].sem_base = &sem[semtot]; | |
950 | semtot += nsems; | |
951 | semtots++; | |
952 | bzero(sema[semid].sem_base, | |
953 | sizeof(sema[semid].sem_base[0])*nsems); | |
954 | DPRINTF(("sembase = 0x%x, next = 0x%x\n", sema[semid].sem_base, | |
955 | &sem[semtot])); | |
956 | } else { | |
957 | DPRINTF(("didn't find it and wasn't asked to create it\n")); | |
958 | error = ENOENT; | |
959 | goto done2; | |
960 | } | |
961 | ||
962 | found: | |
963 | td->td_retval[0] = IXSEQ_TO_IPCID(semid, sema[semid].sem_perm); | |
964 | done2: | |
965 | #ifdef __CYGWIN__ | |
966 | if (!error) | |
967 | ipcexit_creat_hookthread (td); | |
968 | #endif | |
969 | mtx_unlock(&Giant); | |
970 | return (error); | |
971 | } | |
972 | ||
973 | #ifndef _SYS_SYSPROTO_H_ | |
974 | struct semop_args { | |
975 | int semid; | |
976 | struct sembuf *sops; | |
977 | size_t nsops; | |
978 | }; | |
979 | #endif | |
980 | ||
981 | /* | |
982 | * MPSAFE | |
983 | */ | |
984 | int | |
985 | semop(struct thread *td, struct semop_args *uap) | |
986 | { | |
c6ef5fb7 CV |
987 | #define SMALL_SOPS 8 |
988 | struct sembuf small_sops[SMALL_SOPS]; | |
282113ba CV |
989 | int semid = uap->semid; |
990 | size_t nsops = uap->nsops; | |
991 | struct sembuf *sops; | |
992 | struct semid_ds *semaptr; | |
993 | struct sembuf *sopptr = 0; | |
994 | struct sem *semptr = 0; | |
995 | struct sem_undo *suptr; | |
996 | struct mtx *sema_mtxp; | |
997 | size_t i, j, k; | |
998 | int error; | |
999 | int do_wakeup, do_undos; | |
1000 | ||
1001 | DPRINTF(("call to semop(%d, 0x%x, %u)\n", semid, uap->sops, nsops)); | |
1002 | ||
1003 | if (!jail_sysvipc_allowed && jailed(td->td_ucred)) | |
1004 | return (ENOSYS); | |
1005 | ||
1006 | semid = IPCID_TO_IX(semid); /* Convert back to zero origin */ | |
1007 | ||
1008 | if (semid < 0 || semid >= seminfo.semmni) | |
1009 | return (EINVAL); | |
1010 | ||
1011 | /* Allocate memory for sem_ops */ | |
c6ef5fb7 CV |
1012 | if (nsops <= SMALL_SOPS) |
1013 | sops = small_sops; | |
1014 | else if (nsops <= (unsigned long) seminfo.semopm) | |
1015 | sops = (struct sembuf *) sys_malloc(nsops * sizeof(*sops), M_SEM, M_WAITOK); | |
1016 | else { | |
282113ba CV |
1017 | DPRINTF(("too many sops (max=%d, nsops=%d)\n", seminfo.semopm, |
1018 | nsops)); | |
1019 | return (E2BIG); | |
1020 | } | |
282113ba CV |
1021 | if ((error = copyin(uap->sops, sops, nsops * sizeof(sops[0]))) != 0) { |
1022 | DPRINTF(("error = %d from copyin(%08x, %08x, %d)\n", error, | |
1023 | uap->sops, sops, nsops * sizeof(sops[0]))); | |
c6ef5fb7 CV |
1024 | if (sops != small_sops) |
1025 | sys_free(sops, M_SEM); | |
282113ba CV |
1026 | return (error); |
1027 | } | |
1028 | ||
1029 | semaptr = &sema[semid]; | |
1030 | sema_mtxp = &sema_mtx[semid]; | |
1031 | mtx_lock(sema_mtxp); | |
1032 | if ((semaptr->sem_perm.mode & SEM_ALLOC) == 0) { | |
1033 | error = EINVAL; | |
1034 | goto done2; | |
1035 | } | |
1036 | if (semaptr->sem_perm.seq != IPCID_TO_SEQ(uap->semid)) { | |
1037 | error = EINVAL; | |
1038 | goto done2; | |
1039 | } | |
1040 | /* | |
1041 | * Initial pass thru sops to see what permissions are needed. | |
1042 | * Also perform any checks that don't need repeating on each | |
1043 | * attempt to satisfy the request vector. | |
1044 | */ | |
1045 | j = 0; /* permission needed */ | |
1046 | do_undos = 0; | |
1047 | for (i = 0; i < nsops; i++) { | |
1048 | sopptr = &sops[i]; | |
1049 | if (sopptr->sem_num >= semaptr->sem_nsems) { | |
1050 | error = EFBIG; | |
1051 | goto done2; | |
1052 | } | |
1053 | if (sopptr->sem_flg & SEM_UNDO && sopptr->sem_op != 0) | |
1054 | do_undos = 1; | |
1055 | j |= (sopptr->sem_op == 0) ? SEM_R : SEM_A; | |
1056 | } | |
1057 | ||
1058 | if ((error = ipcperm(td, &semaptr->sem_perm, j))) { | |
1059 | DPRINTF(("error = %d from ipaccess\n", error)); | |
1060 | goto done2; | |
1061 | } | |
1062 | ||
1063 | /* | |
1064 | * Loop trying to satisfy the vector of requests. | |
1065 | * If we reach a point where we must wait, any requests already | |
1066 | * performed are rolled back and we go to sleep until some other | |
1067 | * process wakes us up. At this point, we start all over again. | |
1068 | * | |
1069 | * This ensures that from the perspective of other tasks, a set | |
1070 | * of requests is atomic (never partially satisfied). | |
1071 | */ | |
1072 | for (;;) { | |
1073 | do_wakeup = 0; | |
1074 | error = 0; /* error return if necessary */ | |
1075 | ||
1076 | for (i = 0; i < nsops; i++) { | |
1077 | sopptr = &sops[i]; | |
1078 | semptr = &semaptr->sem_base[sopptr->sem_num]; | |
1079 | ||
1080 | DPRINTF(( | |
dafef5e2 | 1081 | "semop: semaptr=%x, sem_base=%x, " |
282113ba CV |
1082 | "semptr=%x, sem[%d]=%d : op=%d, flag=%s\n", |
1083 | semaptr, semaptr->sem_base, semptr, | |
1084 | sopptr->sem_num, semptr->semval, sopptr->sem_op, | |
1085 | (sopptr->sem_flg & IPC_NOWAIT) ? | |
1086 | "nowait" : "wait")); | |
1087 | ||
1088 | if (sopptr->sem_op < 0) { | |
1089 | if (semptr->semval + sopptr->sem_op < 0) { | |
1090 | DPRINTF(("semop: can't do it now\n")); | |
1091 | break; | |
1092 | } else { | |
1093 | semptr->semval += sopptr->sem_op; | |
1094 | if (semptr->semval == 0 && | |
1095 | semptr->semzcnt > 0) | |
1096 | do_wakeup = 1; | |
1097 | } | |
1098 | } else if (sopptr->sem_op == 0) { | |
1099 | if (semptr->semval != 0) { | |
1100 | DPRINTF(("semop: not zero now\n")); | |
1101 | break; | |
1102 | } | |
1103 | } else if (semptr->semval + sopptr->sem_op > | |
1104 | seminfo.semvmx) { | |
1105 | error = ERANGE; | |
1106 | break; | |
1107 | } else { | |
1108 | if (semptr->semncnt > 0) | |
1109 | do_wakeup = 1; | |
1110 | semptr->semval += sopptr->sem_op; | |
1111 | } | |
1112 | } | |
1113 | ||
1114 | /* | |
1115 | * Did we get through the entire vector? | |
1116 | */ | |
1117 | if (i >= nsops) | |
1118 | goto done; | |
1119 | ||
1120 | /* | |
1121 | * No ... rollback anything that we've already done | |
1122 | */ | |
1123 | DPRINTF(("semop: rollback 0 through %d\n", i-1)); | |
1124 | for (j = 0; j < i; j++) | |
1125 | semaptr->sem_base[sops[j].sem_num].semval -= | |
1126 | sops[j].sem_op; | |
1127 | ||
1128 | /* If we detected an error, return it */ | |
1129 | if (error != 0) | |
1130 | goto done2; | |
1131 | ||
1132 | /* | |
1133 | * If the request that we couldn't satisfy has the | |
1134 | * NOWAIT flag set then return with EAGAIN. | |
1135 | */ | |
1136 | if (sopptr->sem_flg & IPC_NOWAIT) { | |
1137 | error = EAGAIN; | |
1138 | goto done2; | |
1139 | } | |
1140 | ||
1141 | if (sopptr->sem_op == 0) | |
1142 | semptr->semzcnt++; | |
1143 | else | |
1144 | semptr->semncnt++; | |
1145 | ||
1146 | DPRINTF(("semop: good night!\n")); | |
1147 | error = msleep(semaptr, sema_mtxp, (PZERO - 4) | PCATCH, | |
1148 | "semwait", 0); | |
1149 | DPRINTF(("semop: good morning (error=%d)!\n", error)); | |
c6ef5fb7 | 1150 | /* return code is checked below, after sem[nz]cnt-- */ |
282113ba CV |
1151 | |
1152 | /* | |
1153 | * Make sure that the semaphore still exists | |
1154 | */ | |
1155 | if ((semaptr->sem_perm.mode & SEM_ALLOC) == 0 || | |
1156 | semaptr->sem_perm.seq != IPCID_TO_SEQ(uap->semid)) { | |
1157 | error = EIDRM; | |
1158 | goto done2; | |
1159 | } | |
1160 | ||
1161 | /* | |
1162 | * The semaphore is still alive. Readjust the count of | |
1163 | * waiting processes. | |
1164 | */ | |
1165 | if (sopptr->sem_op == 0) | |
1166 | semptr->semzcnt--; | |
1167 | else | |
1168 | semptr->semncnt--; | |
c6ef5fb7 CV |
1169 | |
1170 | /* | |
1171 | * Is it really morning, or was our sleep interrupted? | |
1172 | * (Delayed check of msleep() return code because we | |
1173 | * need to decrement sem[nz]cnt either way.) | |
1174 | */ | |
1175 | if (error != 0) { | |
1176 | #ifdef __CYGWIN__ | |
1177 | if (error != EIDRM) | |
1178 | #endif /* __CYGWIN__ */ | |
1179 | error = EINTR; | |
1180 | goto done2; | |
1181 | } | |
1182 | DPRINTF(("semop: good morning!\n")); | |
282113ba CV |
1183 | } |
1184 | ||
1185 | done: | |
1186 | /* | |
1187 | * Process any SEM_UNDO requests. | |
1188 | */ | |
1189 | if (do_undos) { | |
1190 | SEMUNDO_LOCK(); | |
1191 | suptr = NULL; | |
1192 | for (i = 0; i < nsops; i++) { | |
1193 | /* | |
1194 | * We only need to deal with SEM_UNDO's for non-zero | |
1195 | * op's. | |
1196 | */ | |
1197 | int adjval; | |
1198 | ||
1199 | if ((sops[i].sem_flg & SEM_UNDO) == 0) | |
1200 | continue; | |
1201 | adjval = sops[i].sem_op; | |
1202 | if (adjval == 0) | |
1203 | continue; | |
1204 | error = semundo_adjust(td, &suptr, semid, | |
1205 | sops[i].sem_num, -adjval); | |
1206 | if (error == 0) | |
1207 | continue; | |
1208 | ||
1209 | /* | |
1210 | * Oh-Oh! We ran out of either sem_undo's or undo's. | |
1211 | * Rollback the adjustments to this point and then | |
1212 | * rollback the semaphore ups and down so we can return | |
1213 | * with an error with all structures restored. We | |
1214 | * rollback the undo's in the exact reverse order that | |
1215 | * we applied them. This guarantees that we won't run | |
1216 | * out of space as we roll things back out. | |
1217 | */ | |
1218 | for (j = 0; j < i; j++) { | |
1219 | k = i - j - 1; | |
1220 | if ((sops[k].sem_flg & SEM_UNDO) == 0) | |
1221 | continue; | |
1222 | adjval = sops[k].sem_op; | |
1223 | if (adjval == 0) | |
1224 | continue; | |
1225 | if (semundo_adjust(td, &suptr, semid, | |
1226 | sops[k].sem_num, adjval) != 0) | |
1227 | panic("semop - can't undo undos"); | |
1228 | } | |
1229 | ||
1230 | for (j = 0; j < nsops; j++) | |
1231 | semaptr->sem_base[sops[j].sem_num].semval -= | |
1232 | sops[j].sem_op; | |
1233 | ||
1234 | DPRINTF(("error = %d from semundo_adjust\n", error)); | |
1235 | SEMUNDO_UNLOCK(); | |
1236 | goto done2; | |
1237 | } /* loop through the sops */ | |
1238 | SEMUNDO_UNLOCK(); | |
1239 | } /* if (do_undos) */ | |
1240 | ||
1241 | /* We're definitely done - set the sempid's and time */ | |
1242 | for (i = 0; i < nsops; i++) { | |
1243 | sopptr = &sops[i]; | |
1244 | semptr = &semaptr->sem_base[sopptr->sem_num]; | |
1245 | semptr->sempid = td->td_proc->p_pid; | |
1246 | } | |
1247 | semaptr->sem_otime = time (NULL); | |
1248 | ||
1249 | /* | |
1250 | * Do a wakeup if any semaphore was up'd whilst something was | |
1251 | * sleeping on it. | |
1252 | */ | |
1253 | if (do_wakeup) { | |
1254 | DPRINTF(("semop: doing wakeup\n")); | |
1255 | wakeup(semaptr); | |
1256 | DPRINTF(("semop: back from wakeup\n")); | |
1257 | } | |
1258 | DPRINTF(("semop: done\n")); | |
1259 | td->td_retval[0] = 0; | |
1260 | done2: | |
1261 | mtx_unlock(sema_mtxp); | |
c6ef5fb7 CV |
1262 | if (sops != small_sops) |
1263 | sys_free(sops, M_SEM); | |
282113ba CV |
1264 | return (error); |
1265 | } | |
1266 | ||
1267 | /* | |
1268 | * Go through the undo structures for this process and apply the adjustments to | |
1269 | * semaphores. | |
1270 | */ | |
1271 | void | |
1272 | semexit_myhook(void *arg, struct proc *p) | |
1273 | { | |
1274 | struct sem_undo *suptr; | |
1275 | struct sem_undo **supptr; | |
1276 | ||
282113ba CV |
1277 | /* |
1278 | * Go through the chain of undo vectors looking for one | |
1279 | * associated with this process. | |
1280 | */ | |
1281 | SEMUNDO_HOOKLOCK(); | |
1282 | SLIST_FOREACH_PREVPTR(suptr, supptr, &semu_list, un_next) { | |
ddb1a4c1 | 1283 | #ifdef __CYGWIN__ |
dafef5e2 | 1284 | if (suptr->un_proc == p->winpid) |
ddb1a4c1 | 1285 | #else |
282113ba | 1286 | if (suptr->un_proc == p) |
ddb1a4c1 | 1287 | #endif |
282113ba CV |
1288 | break; |
1289 | } | |
dafef5e2 | 1290 | #ifndef __CYGWIN__ |
282113ba | 1291 | SEMUNDO_UNLOCK(); |
dafef5e2 | 1292 | #endif |
282113ba | 1293 | |
dafef5e2 CV |
1294 | if (suptr == NULL) { |
1295 | SEMUNDO_UNLOCK(); | |
282113ba | 1296 | return; |
dafef5e2 | 1297 | } |
282113ba | 1298 | |
ddb1a4c1 CV |
1299 | #ifdef __CYGWIN__ |
1300 | DPRINTF(("proc @%u(%u) has undo structure with %d entries\n", | |
1301 | p->cygpid, p->winpid, suptr->un_cnt)); | |
1302 | #else | |
282113ba CV |
1303 | DPRINTF(("proc @%08x has undo structure with %d entries\n", p, |
1304 | suptr->un_cnt)); | |
ddb1a4c1 | 1305 | #endif |
282113ba CV |
1306 | |
1307 | /* | |
1308 | * If there are any active undo elements then process them. | |
1309 | */ | |
1310 | if (suptr->un_cnt > 0) { | |
1311 | int ix; | |
1312 | ||
1313 | for (ix = 0; ix < suptr->un_cnt; ix++) { | |
1314 | int semid = suptr->un_ent[ix].un_id; | |
1315 | int semnum = suptr->un_ent[ix].un_num; | |
1316 | int adjval = suptr->un_ent[ix].un_adjval; | |
1317 | struct semid_ds *semaptr; | |
1318 | struct mtx *sema_mtxp; | |
1319 | ||
1320 | semaptr = &sema[semid]; | |
1321 | sema_mtxp = &sema_mtx[semid]; | |
1322 | #ifdef __CYGWIN__ | |
1323 | _mtx_lock(sema_mtxp, p->winpid, __FILE__, __LINE__); | |
1324 | #else | |
1325 | mtx_lock(sema_mtxp); | |
282113ba | 1326 | SEMUNDO_HOOKLOCK(); |
dafef5e2 | 1327 | #endif |
282113ba CV |
1328 | if ((semaptr->sem_perm.mode & SEM_ALLOC) == 0) |
1329 | panic("semexit - semid not allocated"); | |
1330 | if (semnum >= semaptr->sem_nsems) | |
1331 | panic("semexit - semnum out of range"); | |
1332 | ||
1333 | DPRINTF(( | |
ddb1a4c1 | 1334 | #ifdef __CYGWIN__ |
dafef5e2 | 1335 | "semexit: %u id=%d num=%d(adj=%d) ; sem=%d\n", |
ddb1a4c1 | 1336 | #else |
282113ba | 1337 | "semexit: %08x id=%d num=%d(adj=%d) ; sem=%d\n", |
ddb1a4c1 | 1338 | #endif |
dafef5e2 | 1339 | suptr->un_proc, suptr->un_ent[ix].un_id, |
282113ba CV |
1340 | suptr->un_ent[ix].un_num, |
1341 | suptr->un_ent[ix].un_adjval, | |
1342 | semaptr->sem_base[semnum].semval)); | |
1343 | ||
1344 | if (adjval < 0) { | |
1345 | if (semaptr->sem_base[semnum].semval < -adjval) | |
1346 | semaptr->sem_base[semnum].semval = 0; | |
1347 | else | |
1348 | semaptr->sem_base[semnum].semval += | |
1349 | adjval; | |
1350 | } else | |
1351 | semaptr->sem_base[semnum].semval += adjval; | |
1352 | ||
1353 | wakeup(semaptr); | |
1354 | DPRINTF(("semexit: back from wakeup\n")); | |
dafef5e2 CV |
1355 | _mtx_unlock(sema_mtxp, __FILE__, __LINE__); |
1356 | #ifndef __CYGWIN__ | |
282113ba | 1357 | SEMUNDO_UNLOCK(); |
dafef5e2 | 1358 | #endif |
282113ba CV |
1359 | } |
1360 | } | |
1361 | ||
1362 | /* | |
1363 | * Deallocate the undo vector. | |
1364 | */ | |
dafef5e2 CV |
1365 | DPRINTF(("removing vector (%u)\n", suptr->un_proc)); |
1366 | #ifdef __CYGWIN__ | |
1367 | suptr->un_proc = 0; | |
1368 | #else | |
282113ba | 1369 | suptr->un_proc = NULL; |
dafef5e2 | 1370 | #endif |
282113ba | 1371 | *supptr = SLIST_NEXT(suptr, un_next); |
dafef5e2 CV |
1372 | #ifdef __CYGWIN__ |
1373 | SEMUNDO_UNLOCK(); | |
1374 | #endif | |
282113ba CV |
1375 | } |
1376 | ||
1377 | #ifndef __CYGWIN__ | |
1378 | static int | |
1379 | sysctl_sema(SYSCTL_HANDLER_ARGS) | |
1380 | { | |
1381 | ||
1382 | return (SYSCTL_OUT(req, sema, | |
1383 | sizeof(struct semid_ds) * seminfo.semmni)); | |
1384 | } | |
1385 | #endif /* __CYGWIN__ */ | |
1386 | #endif /* __OUTSIDE_CYGWIN__ */ |