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72#include <linux/slab.h>
73#include <linux/spinlock.h>
74#include <linux/init.h>
75#include <linux/proc_fs.h>
76#include <linux/time.h>
77#include <linux/security.h>
78#include <linux/syscalls.h>
79#include <linux/audit.h>
80#include <linux/capability.h>
81#include <linux/seq_file.h>
82#include <linux/rwsem.h>
83#include <linux/nsproxy.h>
84#include <linux/ipc_namespace.h>
85
86#include <linux/uaccess.h>
87#include "util.h"
88
89
90struct sem {
91 int semval;
92
93
94
95
96
97
98
99 int sempid;
100 spinlock_t lock;
101 struct list_head pending_alter;
102
103 struct list_head pending_const;
104
105 time_t sem_otime;
106} ____cacheline_aligned_in_smp;
107
108
109struct sem_queue {
110 struct list_head list;
111 struct task_struct *sleeper;
112 struct sem_undo *undo;
113 int pid;
114 int status;
115 struct sembuf *sops;
116 struct sembuf *blocking;
117 int nsops;
118 bool alter;
119 bool dupsop;
120};
121
122
123
124
125struct sem_undo {
126 struct list_head list_proc;
127
128
129 struct rcu_head rcu;
130 struct sem_undo_list *ulp;
131 struct list_head list_id;
132
133 int semid;
134 short *semadj;
135
136};
137
138
139
140
141struct sem_undo_list {
142 atomic_t refcnt;
143 spinlock_t lock;
144 struct list_head list_proc;
145};
146
147
148#define sem_ids(ns) ((ns)->ids[IPC_SEM_IDS])
149
150#define sem_checkid(sma, semid) ipc_checkid(&sma->sem_perm, semid)
151
152static int newary(struct ipc_namespace *, struct ipc_params *);
153static void freeary(struct ipc_namespace *, struct kern_ipc_perm *);
154#ifdef CONFIG_PROC_FS
155static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
156#endif
157
158#define SEMMSL_FAST 256
159#define SEMOPM_FAST 64
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180#define sc_semmsl sem_ctls[0]
181#define sc_semmns sem_ctls[1]
182#define sc_semopm sem_ctls[2]
183#define sc_semmni sem_ctls[3]
184
185void sem_init_ns(struct ipc_namespace *ns)
186{
187 ns->sc_semmsl = SEMMSL;
188 ns->sc_semmns = SEMMNS;
189 ns->sc_semopm = SEMOPM;
190 ns->sc_semmni = SEMMNI;
191 ns->used_sems = 0;
192 ipc_init_ids(&ns->ids[IPC_SEM_IDS]);
193}
194
195#ifdef CONFIG_IPC_NS
196void sem_exit_ns(struct ipc_namespace *ns)
197{
198 free_ipcs(ns, &sem_ids(ns), freeary);
199 idr_destroy(&ns->ids[IPC_SEM_IDS].ipcs_idr);
200}
201#endif
202
203void __init sem_init(void)
204{
205 sem_init_ns(&init_ipc_ns);
206 ipc_init_proc_interface("sysvipc/sem",
207 " key semid perms nsems uid gid cuid cgid otime ctime\n",
208 IPC_SEM_IDS, sysvipc_sem_proc_show);
209}
210
211
212
213
214
215
216
217
218static void unmerge_queues(struct sem_array *sma)
219{
220 struct sem_queue *q, *tq;
221
222
223 if (sma->complex_count)
224 return;
225
226
227
228
229
230 list_for_each_entry_safe(q, tq, &sma->pending_alter, list) {
231 struct sem *curr;
232 curr = &sma->sem_base[q->sops[0].sem_num];
233
234 list_add_tail(&q->list, &curr->pending_alter);
235 }
236 INIT_LIST_HEAD(&sma->pending_alter);
237}
238
239
240
241
242
243
244
245
246
247
248static void merge_queues(struct sem_array *sma)
249{
250 int i;
251 for (i = 0; i < sma->sem_nsems; i++) {
252 struct sem *sem = sma->sem_base + i;
253
254 list_splice_init(&sem->pending_alter, &sma->pending_alter);
255 }
256}
257
258static void sem_rcu_free(struct rcu_head *head)
259{
260 struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
261 struct sem_array *sma = ipc_rcu_to_struct(p);
262
263 security_sem_free(sma);
264 ipc_rcu_free(head);
265}
266
267
268
269
270
271static void complexmode_enter(struct sem_array *sma)
272{
273 int i;
274 struct sem *sem;
275
276 if (sma->complex_mode) {
277
278 return;
279 }
280
281
282
283
284
285 smp_store_mb(sma->complex_mode, true);
286
287 for (i = 0; i < sma->sem_nsems; i++) {
288 sem = sma->sem_base + i;
289 spin_unlock_wait(&sem->lock);
290 }
291
292
293
294
295
296
297
298 smp_rmb();
299}
300
301
302
303
304
305static void complexmode_tryleave(struct sem_array *sma)
306{
307 if (sma->complex_count) {
308
309
310
311 return;
312 }
313
314
315
316
317
318
319 smp_store_release(&sma->complex_mode, false);
320}
321
322#define SEM_GLOBAL_LOCK (-1)
323
324
325
326
327
328
329
330static inline int sem_lock(struct sem_array *sma, struct sembuf *sops,
331 int nsops)
332{
333 struct sem *sem;
334
335 if (nsops != 1) {
336
337 ipc_lock_object(&sma->sem_perm);
338
339
340 complexmode_enter(sma);
341 return SEM_GLOBAL_LOCK;
342 }
343
344
345
346
347
348
349
350
351 sem = sma->sem_base + sops->sem_num;
352
353
354
355
356
357 if (!sma->complex_mode) {
358
359
360
361
362 spin_lock(&sem->lock);
363
364
365
366
367
368
369
370 smp_mb();
371
372 if (!smp_load_acquire(&sma->complex_mode)) {
373
374 return sops->sem_num;
375 }
376 spin_unlock(&sem->lock);
377 }
378
379
380 ipc_lock_object(&sma->sem_perm);
381
382 if (sma->complex_count == 0) {
383
384
385
386
387 spin_lock(&sem->lock);
388 ipc_unlock_object(&sma->sem_perm);
389 return sops->sem_num;
390 } else {
391
392
393
394 complexmode_enter(sma);
395 return SEM_GLOBAL_LOCK;
396 }
397}
398
399static inline void sem_unlock(struct sem_array *sma, int locknum)
400{
401 if (locknum == SEM_GLOBAL_LOCK) {
402 unmerge_queues(sma);
403 complexmode_tryleave(sma);
404 ipc_unlock_object(&sma->sem_perm);
405 } else {
406 struct sem *sem = sma->sem_base + locknum;
407 spin_unlock(&sem->lock);
408 }
409}
410
411
412
413
414
415
416
417static inline struct sem_array *sem_obtain_object(struct ipc_namespace *ns, int id)
418{
419 struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&sem_ids(ns), id);
420
421 if (IS_ERR(ipcp))
422 return ERR_CAST(ipcp);
423
424 return container_of(ipcp, struct sem_array, sem_perm);
425}
426
427static inline struct sem_array *sem_obtain_object_check(struct ipc_namespace *ns,
428 int id)
429{
430 struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&sem_ids(ns), id);
431
432 if (IS_ERR(ipcp))
433 return ERR_CAST(ipcp);
434
435 return container_of(ipcp, struct sem_array, sem_perm);
436}
437
438static inline void sem_lock_and_putref(struct sem_array *sma)
439{
440 sem_lock(sma, NULL, -1);
441 ipc_rcu_putref(sma, sem_rcu_free);
442}
443
444static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s)
445{
446 ipc_rmid(&sem_ids(ns), &s->sem_perm);
447}
448
449
450
451
452
453
454
455
456static int newary(struct ipc_namespace *ns, struct ipc_params *params)
457{
458 int id;
459 int retval;
460 struct sem_array *sma;
461 int size;
462 key_t key = params->key;
463 int nsems = params->u.nsems;
464 int semflg = params->flg;
465 int i;
466
467 if (!nsems)
468 return -EINVAL;
469 if (ns->used_sems + nsems > ns->sc_semmns)
470 return -ENOSPC;
471
472 size = sizeof(*sma) + nsems * sizeof(struct sem);
473 sma = ipc_rcu_alloc(size);
474 if (!sma)
475 return -ENOMEM;
476
477 memset(sma, 0, size);
478
479 sma->sem_perm.mode = (semflg & S_IRWXUGO);
480 sma->sem_perm.key = key;
481
482 sma->sem_perm.security = NULL;
483 retval = security_sem_alloc(sma);
484 if (retval) {
485 ipc_rcu_putref(sma, ipc_rcu_free);
486 return retval;
487 }
488
489 sma->sem_base = (struct sem *) &sma[1];
490
491 for (i = 0; i < nsems; i++) {
492 INIT_LIST_HEAD(&sma->sem_base[i].pending_alter);
493 INIT_LIST_HEAD(&sma->sem_base[i].pending_const);
494 spin_lock_init(&sma->sem_base[i].lock);
495 }
496
497 sma->complex_count = 0;
498 sma->complex_mode = true;
499 INIT_LIST_HEAD(&sma->pending_alter);
500 INIT_LIST_HEAD(&sma->pending_const);
501 INIT_LIST_HEAD(&sma->list_id);
502 sma->sem_nsems = nsems;
503 sma->sem_ctime = get_seconds();
504
505 id = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni);
506 if (id < 0) {
507 ipc_rcu_putref(sma, sem_rcu_free);
508 return id;
509 }
510 ns->used_sems += nsems;
511
512 sem_unlock(sma, -1);
513 rcu_read_unlock();
514
515 return sma->sem_perm.id;
516}
517
518
519
520
521
522static inline int sem_security(struct kern_ipc_perm *ipcp, int semflg)
523{
524 struct sem_array *sma;
525
526 sma = container_of(ipcp, struct sem_array, sem_perm);
527 return security_sem_associate(sma, semflg);
528}
529
530
531
532
533static inline int sem_more_checks(struct kern_ipc_perm *ipcp,
534 struct ipc_params *params)
535{
536 struct sem_array *sma;
537
538 sma = container_of(ipcp, struct sem_array, sem_perm);
539 if (params->u.nsems > sma->sem_nsems)
540 return -EINVAL;
541
542 return 0;
543}
544
545SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg)
546{
547 struct ipc_namespace *ns;
548 static const struct ipc_ops sem_ops = {
549 .getnew = newary,
550 .associate = sem_security,
551 .more_checks = sem_more_checks,
552 };
553 struct ipc_params sem_params;
554
555 ns = current->nsproxy->ipc_ns;
556
557 if (nsems < 0 || nsems > ns->sc_semmsl)
558 return -EINVAL;
559
560 sem_params.key = key;
561 sem_params.flg = semflg;
562 sem_params.u.nsems = nsems;
563
564 return ipcget(ns, &sem_ids(ns), &sem_ops, &sem_params);
565}
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584static int perform_atomic_semop_slow(struct sem_array *sma, struct sem_queue *q)
585{
586 int result, sem_op, nsops, pid;
587 struct sembuf *sop;
588 struct sem *curr;
589 struct sembuf *sops;
590 struct sem_undo *un;
591
592 sops = q->sops;
593 nsops = q->nsops;
594 un = q->undo;
595
596 for (sop = sops; sop < sops + nsops; sop++) {
597 curr = sma->sem_base + sop->sem_num;
598 sem_op = sop->sem_op;
599 result = curr->semval;
600
601 if (!sem_op && result)
602 goto would_block;
603
604 result += sem_op;
605 if (result < 0)
606 goto would_block;
607 if (result > SEMVMX)
608 goto out_of_range;
609
610 if (sop->sem_flg & SEM_UNDO) {
611 int undo = un->semadj[sop->sem_num] - sem_op;
612
613 if (undo < (-SEMAEM - 1) || undo > SEMAEM)
614 goto out_of_range;
615 un->semadj[sop->sem_num] = undo;
616 }
617
618 curr->semval = result;
619 }
620
621 sop--;
622 pid = q->pid;
623 while (sop >= sops) {
624 sma->sem_base[sop->sem_num].sempid = pid;
625 sop--;
626 }
627
628 return 0;
629
630out_of_range:
631 result = -ERANGE;
632 goto undo;
633
634would_block:
635 q->blocking = sop;
636
637 if (sop->sem_flg & IPC_NOWAIT)
638 result = -EAGAIN;
639 else
640 result = 1;
641
642undo:
643 sop--;
644 while (sop >= sops) {
645 sem_op = sop->sem_op;
646 sma->sem_base[sop->sem_num].semval -= sem_op;
647 if (sop->sem_flg & SEM_UNDO)
648 un->semadj[sop->sem_num] += sem_op;
649 sop--;
650 }
651
652 return result;
653}
654
655static int perform_atomic_semop(struct sem_array *sma, struct sem_queue *q)
656{
657 int result, sem_op, nsops;
658 struct sembuf *sop;
659 struct sem *curr;
660 struct sembuf *sops;
661 struct sem_undo *un;
662
663 sops = q->sops;
664 nsops = q->nsops;
665 un = q->undo;
666
667 if (unlikely(q->dupsop))
668 return perform_atomic_semop_slow(sma, q);
669
670
671
672
673
674
675
676 for (sop = sops; sop < sops + nsops; sop++) {
677 curr = sma->sem_base + sop->sem_num;
678 sem_op = sop->sem_op;
679 result = curr->semval;
680
681 if (!sem_op && result)
682 goto would_block;
683
684 result += sem_op;
685 if (result < 0)
686 goto would_block;
687
688 if (result > SEMVMX)
689 return -ERANGE;
690
691 if (sop->sem_flg & SEM_UNDO) {
692 int undo = un->semadj[sop->sem_num] - sem_op;
693
694
695 if (undo < (-SEMAEM - 1) || undo > SEMAEM)
696 return -ERANGE;
697 }
698 }
699
700 for (sop = sops; sop < sops + nsops; sop++) {
701 curr = sma->sem_base + sop->sem_num;
702 sem_op = sop->sem_op;
703 result = curr->semval;
704
705 if (sop->sem_flg & SEM_UNDO) {
706 int undo = un->semadj[sop->sem_num] - sem_op;
707
708 un->semadj[sop->sem_num] = undo;
709 }
710 curr->semval += sem_op;
711 curr->sempid = q->pid;
712 }
713
714 return 0;
715
716would_block:
717 q->blocking = sop;
718 return sop->sem_flg & IPC_NOWAIT ? -EAGAIN : 1;
719}
720
721static inline void wake_up_sem_queue_prepare(struct sem_queue *q, int error,
722 struct wake_q_head *wake_q)
723{
724 wake_q_add(wake_q, q->sleeper);
725
726
727
728
729
730
731
732 WRITE_ONCE(q->status, error);
733}
734
735static void unlink_queue(struct sem_array *sma, struct sem_queue *q)
736{
737 list_del(&q->list);
738 if (q->nsops > 1)
739 sma->complex_count--;
740}
741
742
743
744
745
746
747
748
749
750
751
752static inline int check_restart(struct sem_array *sma, struct sem_queue *q)
753{
754
755 if (!list_empty(&sma->pending_alter))
756 return 1;
757
758
759 if (q->nsops > 1)
760 return 1;
761
762
763
764
765
766
767
768
769
770
771
772
773 return 0;
774}
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790static int wake_const_ops(struct sem_array *sma, int semnum,
791 struct wake_q_head *wake_q)
792{
793 struct sem_queue *q, *tmp;
794 struct list_head *pending_list;
795 int semop_completed = 0;
796
797 if (semnum == -1)
798 pending_list = &sma->pending_const;
799 else
800 pending_list = &sma->sem_base[semnum].pending_const;
801
802 list_for_each_entry_safe(q, tmp, pending_list, list) {
803 int error = perform_atomic_semop(sma, q);
804
805 if (error > 0)
806 continue;
807
808 unlink_queue(sma, q);
809
810 wake_up_sem_queue_prepare(q, error, wake_q);
811 if (error == 0)
812 semop_completed = 1;
813 }
814
815 return semop_completed;
816}
817
818
819
820
821
822
823
824
825
826
827
828
829static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops,
830 int nsops, struct wake_q_head *wake_q)
831{
832 int i;
833 int semop_completed = 0;
834 int got_zero = 0;
835
836
837 if (sops) {
838 for (i = 0; i < nsops; i++) {
839 int num = sops[i].sem_num;
840
841 if (sma->sem_base[num].semval == 0) {
842 got_zero = 1;
843 semop_completed |= wake_const_ops(sma, num, wake_q);
844 }
845 }
846 } else {
847
848
849
850
851 for (i = 0; i < sma->sem_nsems; i++) {
852 if (sma->sem_base[i].semval == 0) {
853 got_zero = 1;
854 semop_completed |= wake_const_ops(sma, i, wake_q);
855 }
856 }
857 }
858
859
860
861
862 if (got_zero)
863 semop_completed |= wake_const_ops(sma, -1, wake_q);
864
865 return semop_completed;
866}
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885static int update_queue(struct sem_array *sma, int semnum, struct wake_q_head *wake_q)
886{
887 struct sem_queue *q, *tmp;
888 struct list_head *pending_list;
889 int semop_completed = 0;
890
891 if (semnum == -1)
892 pending_list = &sma->pending_alter;
893 else
894 pending_list = &sma->sem_base[semnum].pending_alter;
895
896again:
897 list_for_each_entry_safe(q, tmp, pending_list, list) {
898 int error, restart;
899
900
901
902
903
904
905
906
907 if (semnum != -1 && sma->sem_base[semnum].semval == 0)
908 break;
909
910 error = perform_atomic_semop(sma, q);
911
912
913 if (error > 0)
914 continue;
915
916 unlink_queue(sma, q);
917
918 if (error) {
919 restart = 0;
920 } else {
921 semop_completed = 1;
922 do_smart_wakeup_zero(sma, q->sops, q->nsops, wake_q);
923 restart = check_restart(sma, q);
924 }
925
926 wake_up_sem_queue_prepare(q, error, wake_q);
927 if (restart)
928 goto again;
929 }
930 return semop_completed;
931}
932
933
934
935
936
937
938
939
940
941static void set_semotime(struct sem_array *sma, struct sembuf *sops)
942{
943 if (sops == NULL) {
944 sma->sem_base[0].sem_otime = get_seconds();
945 } else {
946 sma->sem_base[sops[0].sem_num].sem_otime =
947 get_seconds();
948 }
949}
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965static void do_smart_update(struct sem_array *sma, struct sembuf *sops, int nsops,
966 int otime, struct wake_q_head *wake_q)
967{
968 int i;
969
970 otime |= do_smart_wakeup_zero(sma, sops, nsops, wake_q);
971
972 if (!list_empty(&sma->pending_alter)) {
973
974 otime |= update_queue(sma, -1, wake_q);
975 } else {
976 if (!sops) {
977
978
979
980
981 for (i = 0; i < sma->sem_nsems; i++)
982 otime |= update_queue(sma, i, wake_q);
983 } else {
984
985
986
987
988
989
990
991
992
993 for (i = 0; i < nsops; i++) {
994 if (sops[i].sem_op > 0) {
995 otime |= update_queue(sma,
996 sops[i].sem_num, wake_q);
997 }
998 }
999 }
1000 }
1001 if (otime)
1002 set_semotime(sma, sops);
1003}
1004
1005
1006
1007
1008static int check_qop(struct sem_array *sma, int semnum, struct sem_queue *q,
1009 bool count_zero)
1010{
1011 struct sembuf *sop = q->blocking;
1012
1013
1014
1015
1016
1017
1018
1019
1020 pr_info_once("semctl(GETNCNT/GETZCNT) is since 3.16 Single Unix Specification compliant.\n"
1021 "The task %s (%d) triggered the difference, watch for misbehavior.\n",
1022 current->comm, task_pid_nr(current));
1023
1024 if (sop->sem_num != semnum)
1025 return 0;
1026
1027 if (count_zero && sop->sem_op == 0)
1028 return 1;
1029 if (!count_zero && sop->sem_op < 0)
1030 return 1;
1031
1032 return 0;
1033}
1034
1035
1036
1037
1038
1039
1040
1041
1042static int count_semcnt(struct sem_array *sma, ushort semnum,
1043 bool count_zero)
1044{
1045 struct list_head *l;
1046 struct sem_queue *q;
1047 int semcnt;
1048
1049 semcnt = 0;
1050
1051 if (count_zero)
1052 l = &sma->sem_base[semnum].pending_const;
1053 else
1054 l = &sma->sem_base[semnum].pending_alter;
1055
1056 list_for_each_entry(q, l, list) {
1057
1058
1059
1060 semcnt++;
1061 }
1062
1063
1064 list_for_each_entry(q, &sma->pending_alter, list) {
1065 semcnt += check_qop(sma, semnum, q, count_zero);
1066 }
1067 if (count_zero) {
1068 list_for_each_entry(q, &sma->pending_const, list) {
1069 semcnt += check_qop(sma, semnum, q, count_zero);
1070 }
1071 }
1072 return semcnt;
1073}
1074
1075
1076
1077
1078
1079static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
1080{
1081 struct sem_undo *un, *tu;
1082 struct sem_queue *q, *tq;
1083 struct sem_array *sma = container_of(ipcp, struct sem_array, sem_perm);
1084 int i;
1085 DEFINE_WAKE_Q(wake_q);
1086
1087
1088 ipc_assert_locked_object(&sma->sem_perm);
1089 list_for_each_entry_safe(un, tu, &sma->list_id, list_id) {
1090 list_del(&un->list_id);
1091 spin_lock(&un->ulp->lock);
1092 un->semid = -1;
1093 list_del_rcu(&un->list_proc);
1094 spin_unlock(&un->ulp->lock);
1095 kfree_rcu(un, rcu);
1096 }
1097
1098
1099 list_for_each_entry_safe(q, tq, &sma->pending_const, list) {
1100 unlink_queue(sma, q);
1101 wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
1102 }
1103
1104 list_for_each_entry_safe(q, tq, &sma->pending_alter, list) {
1105 unlink_queue(sma, q);
1106 wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
1107 }
1108 for (i = 0; i < sma->sem_nsems; i++) {
1109 struct sem *sem = sma->sem_base + i;
1110 list_for_each_entry_safe(q, tq, &sem->pending_const, list) {
1111 unlink_queue(sma, q);
1112 wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
1113 }
1114 list_for_each_entry_safe(q, tq, &sem->pending_alter, list) {
1115 unlink_queue(sma, q);
1116 wake_up_sem_queue_prepare(q, -EIDRM, &wake_q);
1117 }
1118 }
1119
1120
1121 sem_rmid(ns, sma);
1122 sem_unlock(sma, -1);
1123 rcu_read_unlock();
1124
1125 wake_up_q(&wake_q);
1126 ns->used_sems -= sma->sem_nsems;
1127 ipc_rcu_putref(sma, sem_rcu_free);
1128}
1129
1130static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in, int version)
1131{
1132 switch (version) {
1133 case IPC_64:
1134 return copy_to_user(buf, in, sizeof(*in));
1135 case IPC_OLD:
1136 {
1137 struct semid_ds out;
1138
1139 memset(&out, 0, sizeof(out));
1140
1141 ipc64_perm_to_ipc_perm(&in->sem_perm, &out.sem_perm);
1142
1143 out.sem_otime = in->sem_otime;
1144 out.sem_ctime = in->sem_ctime;
1145 out.sem_nsems = in->sem_nsems;
1146
1147 return copy_to_user(buf, &out, sizeof(out));
1148 }
1149 default:
1150 return -EINVAL;
1151 }
1152}
1153
1154static time_t get_semotime(struct sem_array *sma)
1155{
1156 int i;
1157 time_t res;
1158
1159 res = sma->sem_base[0].sem_otime;
1160 for (i = 1; i < sma->sem_nsems; i++) {
1161 time_t to = sma->sem_base[i].sem_otime;
1162
1163 if (to > res)
1164 res = to;
1165 }
1166 return res;
1167}
1168
1169static int semctl_nolock(struct ipc_namespace *ns, int semid,
1170 int cmd, int version, void __user *p)
1171{
1172 int err;
1173 struct sem_array *sma;
1174
1175 switch (cmd) {
1176 case IPC_INFO:
1177 case SEM_INFO:
1178 {
1179 struct seminfo seminfo;
1180 int max_id;
1181
1182 err = security_sem_semctl(NULL, cmd);
1183 if (err)
1184 return err;
1185
1186 memset(&seminfo, 0, sizeof(seminfo));
1187 seminfo.semmni = ns->sc_semmni;
1188 seminfo.semmns = ns->sc_semmns;
1189 seminfo.semmsl = ns->sc_semmsl;
1190 seminfo.semopm = ns->sc_semopm;
1191 seminfo.semvmx = SEMVMX;
1192 seminfo.semmnu = SEMMNU;
1193 seminfo.semmap = SEMMAP;
1194 seminfo.semume = SEMUME;
1195 down_read(&sem_ids(ns).rwsem);
1196 if (cmd == SEM_INFO) {
1197 seminfo.semusz = sem_ids(ns).in_use;
1198 seminfo.semaem = ns->used_sems;
1199 } else {
1200 seminfo.semusz = SEMUSZ;
1201 seminfo.semaem = SEMAEM;
1202 }
1203 max_id = ipc_get_maxid(&sem_ids(ns));
1204 up_read(&sem_ids(ns).rwsem);
1205 if (copy_to_user(p, &seminfo, sizeof(struct seminfo)))
1206 return -EFAULT;
1207 return (max_id < 0) ? 0 : max_id;
1208 }
1209 case IPC_STAT:
1210 case SEM_STAT:
1211 {
1212 struct semid64_ds tbuf;
1213 int id = 0;
1214
1215 memset(&tbuf, 0, sizeof(tbuf));
1216
1217 rcu_read_lock();
1218 if (cmd == SEM_STAT) {
1219 sma = sem_obtain_object(ns, semid);
1220 if (IS_ERR(sma)) {
1221 err = PTR_ERR(sma);
1222 goto out_unlock;
1223 }
1224 id = sma->sem_perm.id;
1225 } else {
1226 sma = sem_obtain_object_check(ns, semid);
1227 if (IS_ERR(sma)) {
1228 err = PTR_ERR(sma);
1229 goto out_unlock;
1230 }
1231 }
1232
1233 err = -EACCES;
1234 if (ipcperms(ns, &sma->sem_perm, S_IRUGO))
1235 goto out_unlock;
1236
1237 err = security_sem_semctl(sma, cmd);
1238 if (err)
1239 goto out_unlock;
1240
1241 kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
1242 tbuf.sem_otime = get_semotime(sma);
1243 tbuf.sem_ctime = sma->sem_ctime;
1244 tbuf.sem_nsems = sma->sem_nsems;
1245 rcu_read_unlock();
1246 if (copy_semid_to_user(p, &tbuf, version))
1247 return -EFAULT;
1248 return id;
1249 }
1250 default:
1251 return -EINVAL;
1252 }
1253out_unlock:
1254 rcu_read_unlock();
1255 return err;
1256}
1257
1258static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum,
1259 unsigned long arg)
1260{
1261 struct sem_undo *un;
1262 struct sem_array *sma;
1263 struct sem *curr;
1264 int err, val;
1265 DEFINE_WAKE_Q(wake_q);
1266
1267#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN)
1268
1269 val = arg >> 32;
1270#else
1271
1272 val = arg;
1273#endif
1274
1275 if (val > SEMVMX || val < 0)
1276 return -ERANGE;
1277
1278 rcu_read_lock();
1279 sma = sem_obtain_object_check(ns, semid);
1280 if (IS_ERR(sma)) {
1281 rcu_read_unlock();
1282 return PTR_ERR(sma);
1283 }
1284
1285 if (semnum < 0 || semnum >= sma->sem_nsems) {
1286 rcu_read_unlock();
1287 return -EINVAL;
1288 }
1289
1290
1291 if (ipcperms(ns, &sma->sem_perm, S_IWUGO)) {
1292 rcu_read_unlock();
1293 return -EACCES;
1294 }
1295
1296 err = security_sem_semctl(sma, SETVAL);
1297 if (err) {
1298 rcu_read_unlock();
1299 return -EACCES;
1300 }
1301
1302 sem_lock(sma, NULL, -1);
1303
1304 if (!ipc_valid_object(&sma->sem_perm)) {
1305 sem_unlock(sma, -1);
1306 rcu_read_unlock();
1307 return -EIDRM;
1308 }
1309
1310 curr = &sma->sem_base[semnum];
1311
1312 ipc_assert_locked_object(&sma->sem_perm);
1313 list_for_each_entry(un, &sma->list_id, list_id)
1314 un->semadj[semnum] = 0;
1315
1316 curr->semval = val;
1317 curr->sempid = task_tgid_vnr(current);
1318 sma->sem_ctime = get_seconds();
1319
1320 do_smart_update(sma, NULL, 0, 0, &wake_q);
1321 sem_unlock(sma, -1);
1322 rcu_read_unlock();
1323 wake_up_q(&wake_q);
1324 return 0;
1325}
1326
1327static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
1328 int cmd, void __user *p)
1329{
1330 struct sem_array *sma;
1331 struct sem *curr;
1332 int err, nsems;
1333 ushort fast_sem_io[SEMMSL_FAST];
1334 ushort *sem_io = fast_sem_io;
1335 DEFINE_WAKE_Q(wake_q);
1336
1337 rcu_read_lock();
1338 sma = sem_obtain_object_check(ns, semid);
1339 if (IS_ERR(sma)) {
1340 rcu_read_unlock();
1341 return PTR_ERR(sma);
1342 }
1343
1344 nsems = sma->sem_nsems;
1345
1346 err = -EACCES;
1347 if (ipcperms(ns, &sma->sem_perm, cmd == SETALL ? S_IWUGO : S_IRUGO))
1348 goto out_rcu_wakeup;
1349
1350 err = security_sem_semctl(sma, cmd);
1351 if (err)
1352 goto out_rcu_wakeup;
1353
1354 err = -EACCES;
1355 switch (cmd) {
1356 case GETALL:
1357 {
1358 ushort __user *array = p;
1359 int i;
1360
1361 sem_lock(sma, NULL, -1);
1362 if (!ipc_valid_object(&sma->sem_perm)) {
1363 err = -EIDRM;
1364 goto out_unlock;
1365 }
1366 if (nsems > SEMMSL_FAST) {
1367 if (!ipc_rcu_getref(sma)) {
1368 err = -EIDRM;
1369 goto out_unlock;
1370 }
1371 sem_unlock(sma, -1);
1372 rcu_read_unlock();
1373 sem_io = ipc_alloc(sizeof(ushort)*nsems);
1374 if (sem_io == NULL) {
1375 ipc_rcu_putref(sma, sem_rcu_free);
1376 return -ENOMEM;
1377 }
1378
1379 rcu_read_lock();
1380 sem_lock_and_putref(sma);
1381 if (!ipc_valid_object(&sma->sem_perm)) {
1382 err = -EIDRM;
1383 goto out_unlock;
1384 }
1385 }
1386 for (i = 0; i < sma->sem_nsems; i++)
1387 sem_io[i] = sma->sem_base[i].semval;
1388 sem_unlock(sma, -1);
1389 rcu_read_unlock();
1390 err = 0;
1391 if (copy_to_user(array, sem_io, nsems*sizeof(ushort)))
1392 err = -EFAULT;
1393 goto out_free;
1394 }
1395 case SETALL:
1396 {
1397 int i;
1398 struct sem_undo *un;
1399
1400 if (!ipc_rcu_getref(sma)) {
1401 err = -EIDRM;
1402 goto out_rcu_wakeup;
1403 }
1404 rcu_read_unlock();
1405
1406 if (nsems > SEMMSL_FAST) {
1407 sem_io = ipc_alloc(sizeof(ushort)*nsems);
1408 if (sem_io == NULL) {
1409 ipc_rcu_putref(sma, sem_rcu_free);
1410 return -ENOMEM;
1411 }
1412 }
1413
1414 if (copy_from_user(sem_io, p, nsems*sizeof(ushort))) {
1415 ipc_rcu_putref(sma, sem_rcu_free);
1416 err = -EFAULT;
1417 goto out_free;
1418 }
1419
1420 for (i = 0; i < nsems; i++) {
1421 if (sem_io[i] > SEMVMX) {
1422 ipc_rcu_putref(sma, sem_rcu_free);
1423 err = -ERANGE;
1424 goto out_free;
1425 }
1426 }
1427 rcu_read_lock();
1428 sem_lock_and_putref(sma);
1429 if (!ipc_valid_object(&sma->sem_perm)) {
1430 err = -EIDRM;
1431 goto out_unlock;
1432 }
1433
1434 for (i = 0; i < nsems; i++) {
1435 sma->sem_base[i].semval = sem_io[i];
1436 sma->sem_base[i].sempid = task_tgid_vnr(current);
1437 }
1438
1439 ipc_assert_locked_object(&sma->sem_perm);
1440 list_for_each_entry(un, &sma->list_id, list_id) {
1441 for (i = 0; i < nsems; i++)
1442 un->semadj[i] = 0;
1443 }
1444 sma->sem_ctime = get_seconds();
1445
1446 do_smart_update(sma, NULL, 0, 0, &wake_q);
1447 err = 0;
1448 goto out_unlock;
1449 }
1450
1451 }
1452 err = -EINVAL;
1453 if (semnum < 0 || semnum >= nsems)
1454 goto out_rcu_wakeup;
1455
1456 sem_lock(sma, NULL, -1);
1457 if (!ipc_valid_object(&sma->sem_perm)) {
1458 err = -EIDRM;
1459 goto out_unlock;
1460 }
1461 curr = &sma->sem_base[semnum];
1462
1463 switch (cmd) {
1464 case GETVAL:
1465 err = curr->semval;
1466 goto out_unlock;
1467 case GETPID:
1468 err = curr->sempid;
1469 goto out_unlock;
1470 case GETNCNT:
1471 err = count_semcnt(sma, semnum, 0);
1472 goto out_unlock;
1473 case GETZCNT:
1474 err = count_semcnt(sma, semnum, 1);
1475 goto out_unlock;
1476 }
1477
1478out_unlock:
1479 sem_unlock(sma, -1);
1480out_rcu_wakeup:
1481 rcu_read_unlock();
1482 wake_up_q(&wake_q);
1483out_free:
1484 if (sem_io != fast_sem_io)
1485 ipc_free(sem_io);
1486 return err;
1487}
1488
1489static inline unsigned long
1490copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version)
1491{
1492 switch (version) {
1493 case IPC_64:
1494 if (copy_from_user(out, buf, sizeof(*out)))
1495 return -EFAULT;
1496 return 0;
1497 case IPC_OLD:
1498 {
1499 struct semid_ds tbuf_old;
1500
1501 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
1502 return -EFAULT;
1503
1504 out->sem_perm.uid = tbuf_old.sem_perm.uid;
1505 out->sem_perm.gid = tbuf_old.sem_perm.gid;
1506 out->sem_perm.mode = tbuf_old.sem_perm.mode;
1507
1508 return 0;
1509 }
1510 default:
1511 return -EINVAL;
1512 }
1513}
1514
1515
1516
1517
1518
1519
1520static int semctl_down(struct ipc_namespace *ns, int semid,
1521 int cmd, int version, void __user *p)
1522{
1523 struct sem_array *sma;
1524 int err;
1525 struct semid64_ds semid64;
1526 struct kern_ipc_perm *ipcp;
1527
1528 if (cmd == IPC_SET) {
1529 if (copy_semid_from_user(&semid64, p, version))
1530 return -EFAULT;
1531 }
1532
1533 down_write(&sem_ids(ns).rwsem);
1534 rcu_read_lock();
1535
1536 ipcp = ipcctl_pre_down_nolock(ns, &sem_ids(ns), semid, cmd,
1537 &semid64.sem_perm, 0);
1538 if (IS_ERR(ipcp)) {
1539 err = PTR_ERR(ipcp);
1540 goto out_unlock1;
1541 }
1542
1543 sma = container_of(ipcp, struct sem_array, sem_perm);
1544
1545 err = security_sem_semctl(sma, cmd);
1546 if (err)
1547 goto out_unlock1;
1548
1549 switch (cmd) {
1550 case IPC_RMID:
1551 sem_lock(sma, NULL, -1);
1552
1553 freeary(ns, ipcp);
1554 goto out_up;
1555 case IPC_SET:
1556 sem_lock(sma, NULL, -1);
1557 err = ipc_update_perm(&semid64.sem_perm, ipcp);
1558 if (err)
1559 goto out_unlock0;
1560 sma->sem_ctime = get_seconds();
1561 break;
1562 default:
1563 err = -EINVAL;
1564 goto out_unlock1;
1565 }
1566
1567out_unlock0:
1568 sem_unlock(sma, -1);
1569out_unlock1:
1570 rcu_read_unlock();
1571out_up:
1572 up_write(&sem_ids(ns).rwsem);
1573 return err;
1574}
1575
1576SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
1577{
1578 int version;
1579 struct ipc_namespace *ns;
1580 void __user *p = (void __user *)arg;
1581
1582 if (semid < 0)
1583 return -EINVAL;
1584
1585 version = ipc_parse_version(&cmd);
1586 ns = current->nsproxy->ipc_ns;
1587
1588 switch (cmd) {
1589 case IPC_INFO:
1590 case SEM_INFO:
1591 case IPC_STAT:
1592 case SEM_STAT:
1593 return semctl_nolock(ns, semid, cmd, version, p);
1594 case GETALL:
1595 case GETVAL:
1596 case GETPID:
1597 case GETNCNT:
1598 case GETZCNT:
1599 case SETALL:
1600 return semctl_main(ns, semid, semnum, cmd, p);
1601 case SETVAL:
1602 return semctl_setval(ns, semid, semnum, arg);
1603 case IPC_RMID:
1604 case IPC_SET:
1605 return semctl_down(ns, semid, cmd, version, p);
1606 default:
1607 return -EINVAL;
1608 }
1609}
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622static inline int get_undo_list(struct sem_undo_list **undo_listp)
1623{
1624 struct sem_undo_list *undo_list;
1625
1626 undo_list = current->sysvsem.undo_list;
1627 if (!undo_list) {
1628 undo_list = kzalloc(sizeof(*undo_list), GFP_KERNEL);
1629 if (undo_list == NULL)
1630 return -ENOMEM;
1631 spin_lock_init(&undo_list->lock);
1632 atomic_set(&undo_list->refcnt, 1);
1633 INIT_LIST_HEAD(&undo_list->list_proc);
1634
1635 current->sysvsem.undo_list = undo_list;
1636 }
1637 *undo_listp = undo_list;
1638 return 0;
1639}
1640
1641static struct sem_undo *__lookup_undo(struct sem_undo_list *ulp, int semid)
1642{
1643 struct sem_undo *un;
1644
1645 list_for_each_entry_rcu(un, &ulp->list_proc, list_proc) {
1646 if (un->semid == semid)
1647 return un;
1648 }
1649 return NULL;
1650}
1651
1652static struct sem_undo *lookup_undo(struct sem_undo_list *ulp, int semid)
1653{
1654 struct sem_undo *un;
1655
1656 assert_spin_locked(&ulp->lock);
1657
1658 un = __lookup_undo(ulp, semid);
1659 if (un) {
1660 list_del_rcu(&un->list_proc);
1661 list_add_rcu(&un->list_proc, &ulp->list_proc);
1662 }
1663 return un;
1664}
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
1678{
1679 struct sem_array *sma;
1680 struct sem_undo_list *ulp;
1681 struct sem_undo *un, *new;
1682 int nsems, error;
1683
1684 error = get_undo_list(&ulp);
1685 if (error)
1686 return ERR_PTR(error);
1687
1688 rcu_read_lock();
1689 spin_lock(&ulp->lock);
1690 un = lookup_undo(ulp, semid);
1691 spin_unlock(&ulp->lock);
1692 if (likely(un != NULL))
1693 goto out;
1694
1695
1696
1697 sma = sem_obtain_object_check(ns, semid);
1698 if (IS_ERR(sma)) {
1699 rcu_read_unlock();
1700 return ERR_CAST(sma);
1701 }
1702
1703 nsems = sma->sem_nsems;
1704 if (!ipc_rcu_getref(sma)) {
1705 rcu_read_unlock();
1706 un = ERR_PTR(-EIDRM);
1707 goto out;
1708 }
1709 rcu_read_unlock();
1710
1711
1712 new = kzalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL);
1713 if (!new) {
1714 ipc_rcu_putref(sma, sem_rcu_free);
1715 return ERR_PTR(-ENOMEM);
1716 }
1717
1718
1719 rcu_read_lock();
1720 sem_lock_and_putref(sma);
1721 if (!ipc_valid_object(&sma->sem_perm)) {
1722 sem_unlock(sma, -1);
1723 rcu_read_unlock();
1724 kfree(new);
1725 un = ERR_PTR(-EIDRM);
1726 goto out;
1727 }
1728 spin_lock(&ulp->lock);
1729
1730
1731
1732
1733 un = lookup_undo(ulp, semid);
1734 if (un) {
1735 kfree(new);
1736 goto success;
1737 }
1738
1739 new->semadj = (short *) &new[1];
1740 new->ulp = ulp;
1741 new->semid = semid;
1742 assert_spin_locked(&ulp->lock);
1743 list_add_rcu(&new->list_proc, &ulp->list_proc);
1744 ipc_assert_locked_object(&sma->sem_perm);
1745 list_add(&new->list_id, &sma->list_id);
1746 un = new;
1747
1748success:
1749 spin_unlock(&ulp->lock);
1750 sem_unlock(sma, -1);
1751out:
1752 return un;
1753}
1754
1755SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
1756 unsigned, nsops, const struct timespec __user *, timeout)
1757{
1758 int error = -EINVAL;
1759 struct sem_array *sma;
1760 struct sembuf fast_sops[SEMOPM_FAST];
1761 struct sembuf *sops = fast_sops, *sop;
1762 struct sem_undo *un;
1763 int max, locknum;
1764 bool undos = false, alter = false, dupsop = false;
1765 struct sem_queue queue;
1766 unsigned long dup = 0, jiffies_left = 0;
1767 struct ipc_namespace *ns;
1768
1769 ns = current->nsproxy->ipc_ns;
1770
1771 if (nsops < 1 || semid < 0)
1772 return -EINVAL;
1773 if (nsops > ns->sc_semopm)
1774 return -E2BIG;
1775 if (nsops > SEMOPM_FAST) {
1776 sops = kmalloc(sizeof(*sops)*nsops, GFP_KERNEL);
1777 if (sops == NULL)
1778 return -ENOMEM;
1779 }
1780
1781 if (copy_from_user(sops, tsops, nsops * sizeof(*tsops))) {
1782 error = -EFAULT;
1783 goto out_free;
1784 }
1785
1786 if (timeout) {
1787 struct timespec _timeout;
1788 if (copy_from_user(&_timeout, timeout, sizeof(*timeout))) {
1789 error = -EFAULT;
1790 goto out_free;
1791 }
1792 if (_timeout.tv_sec < 0 || _timeout.tv_nsec < 0 ||
1793 _timeout.tv_nsec >= 1000000000L) {
1794 error = -EINVAL;
1795 goto out_free;
1796 }
1797 jiffies_left = timespec_to_jiffies(&_timeout);
1798 }
1799
1800 max = 0;
1801 for (sop = sops; sop < sops + nsops; sop++) {
1802 unsigned long mask = 1ULL << ((sop->sem_num) % BITS_PER_LONG);
1803
1804 if (sop->sem_num >= max)
1805 max = sop->sem_num;
1806 if (sop->sem_flg & SEM_UNDO)
1807 undos = true;
1808 if (dup & mask) {
1809
1810
1811
1812
1813
1814
1815 dupsop = true;
1816 }
1817 if (sop->sem_op != 0) {
1818 alter = true;
1819 dup |= mask;
1820 }
1821 }
1822
1823 if (undos) {
1824
1825 un = find_alloc_undo(ns, semid);
1826 if (IS_ERR(un)) {
1827 error = PTR_ERR(un);
1828 goto out_free;
1829 }
1830 } else {
1831 un = NULL;
1832 rcu_read_lock();
1833 }
1834
1835 sma = sem_obtain_object_check(ns, semid);
1836 if (IS_ERR(sma)) {
1837 rcu_read_unlock();
1838 error = PTR_ERR(sma);
1839 goto out_free;
1840 }
1841
1842 error = -EFBIG;
1843 if (max >= sma->sem_nsems) {
1844 rcu_read_unlock();
1845 goto out_free;
1846 }
1847
1848 error = -EACCES;
1849 if (ipcperms(ns, &sma->sem_perm, alter ? S_IWUGO : S_IRUGO)) {
1850 rcu_read_unlock();
1851 goto out_free;
1852 }
1853
1854 error = security_sem_semop(sma, sops, nsops, alter);
1855 if (error) {
1856 rcu_read_unlock();
1857 goto out_free;
1858 }
1859
1860 error = -EIDRM;
1861 locknum = sem_lock(sma, sops, nsops);
1862
1863
1864
1865
1866
1867
1868
1869
1870 if (!ipc_valid_object(&sma->sem_perm))
1871 goto out_unlock_free;
1872
1873
1874
1875
1876
1877
1878
1879 if (un && un->semid == -1)
1880 goto out_unlock_free;
1881
1882 queue.sops = sops;
1883 queue.nsops = nsops;
1884 queue.undo = un;
1885 queue.pid = task_tgid_vnr(current);
1886 queue.alter = alter;
1887 queue.dupsop = dupsop;
1888
1889 error = perform_atomic_semop(sma, &queue);
1890 if (error == 0) {
1891 DEFINE_WAKE_Q(wake_q);
1892
1893
1894
1895
1896
1897 if (alter)
1898 do_smart_update(sma, sops, nsops, 1, &wake_q);
1899 else
1900 set_semotime(sma, sops);
1901
1902 sem_unlock(sma, locknum);
1903 rcu_read_unlock();
1904 wake_up_q(&wake_q);
1905
1906 goto out_free;
1907 }
1908 if (error < 0)
1909 goto out_unlock_free;
1910
1911
1912
1913
1914
1915 if (nsops == 1) {
1916 struct sem *curr;
1917 curr = &sma->sem_base[sops->sem_num];
1918
1919 if (alter) {
1920 if (sma->complex_count) {
1921 list_add_tail(&queue.list,
1922 &sma->pending_alter);
1923 } else {
1924
1925 list_add_tail(&queue.list,
1926 &curr->pending_alter);
1927 }
1928 } else {
1929 list_add_tail(&queue.list, &curr->pending_const);
1930 }
1931 } else {
1932 if (!sma->complex_count)
1933 merge_queues(sma);
1934
1935 if (alter)
1936 list_add_tail(&queue.list, &sma->pending_alter);
1937 else
1938 list_add_tail(&queue.list, &sma->pending_const);
1939
1940 sma->complex_count++;
1941 }
1942
1943 do {
1944 queue.status = -EINTR;
1945 queue.sleeper = current;
1946
1947 __set_current_state(TASK_INTERRUPTIBLE);
1948 sem_unlock(sma, locknum);
1949 rcu_read_unlock();
1950
1951 if (timeout)
1952 jiffies_left = schedule_timeout(jiffies_left);
1953 else
1954 schedule();
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967 error = READ_ONCE(queue.status);
1968 if (error != -EINTR) {
1969
1970
1971
1972
1973
1974
1975 smp_mb();
1976 goto out_free;
1977 }
1978
1979 rcu_read_lock();
1980 locknum = sem_lock(sma, sops, nsops);
1981
1982 if (!ipc_valid_object(&sma->sem_perm))
1983 goto out_unlock_free;
1984
1985 error = READ_ONCE(queue.status);
1986
1987
1988
1989
1990
1991 if (error != -EINTR)
1992 goto out_unlock_free;
1993
1994
1995
1996
1997 if (timeout && jiffies_left == 0)
1998 error = -EAGAIN;
1999 } while (error == -EINTR && !signal_pending(current));
2000
2001 unlink_queue(sma, &queue);
2002
2003out_unlock_free:
2004 sem_unlock(sma, locknum);
2005 rcu_read_unlock();
2006out_free:
2007 if (sops != fast_sops)
2008 kfree(sops);
2009 return error;
2010}
2011
2012SYSCALL_DEFINE3(semop, int, semid, struct sembuf __user *, tsops,
2013 unsigned, nsops)
2014{
2015 return sys_semtimedop(semid, tsops, nsops, NULL);
2016}
2017
2018
2019
2020
2021
2022int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
2023{
2024 struct sem_undo_list *undo_list;
2025 int error;
2026
2027 if (clone_flags & CLONE_SYSVSEM) {
2028 error = get_undo_list(&undo_list);
2029 if (error)
2030 return error;
2031 atomic_inc(&undo_list->refcnt);
2032 tsk->sysvsem.undo_list = undo_list;
2033 } else
2034 tsk->sysvsem.undo_list = NULL;
2035
2036 return 0;
2037}
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051void exit_sem(struct task_struct *tsk)
2052{
2053 struct sem_undo_list *ulp;
2054
2055 ulp = tsk->sysvsem.undo_list;
2056 if (!ulp)
2057 return;
2058 tsk->sysvsem.undo_list = NULL;
2059
2060 if (!atomic_dec_and_test(&ulp->refcnt))
2061 return;
2062
2063 for (;;) {
2064 struct sem_array *sma;
2065 struct sem_undo *un;
2066 int semid, i;
2067 DEFINE_WAKE_Q(wake_q);
2068
2069 cond_resched();
2070
2071 rcu_read_lock();
2072 un = list_entry_rcu(ulp->list_proc.next,
2073 struct sem_undo, list_proc);
2074 if (&un->list_proc == &ulp->list_proc) {
2075
2076
2077
2078
2079
2080
2081 spin_unlock_wait(&ulp->lock);
2082 rcu_read_unlock();
2083 break;
2084 }
2085 spin_lock(&ulp->lock);
2086 semid = un->semid;
2087 spin_unlock(&ulp->lock);
2088
2089
2090 if (semid == -1) {
2091 rcu_read_unlock();
2092 continue;
2093 }
2094
2095 sma = sem_obtain_object_check(tsk->nsproxy->ipc_ns, semid);
2096
2097 if (IS_ERR(sma)) {
2098 rcu_read_unlock();
2099 continue;
2100 }
2101
2102 sem_lock(sma, NULL, -1);
2103
2104 if (!ipc_valid_object(&sma->sem_perm)) {
2105 sem_unlock(sma, -1);
2106 rcu_read_unlock();
2107 continue;
2108 }
2109 un = __lookup_undo(ulp, semid);
2110 if (un == NULL) {
2111
2112
2113
2114 sem_unlock(sma, -1);
2115 rcu_read_unlock();
2116 continue;
2117 }
2118
2119
2120 ipc_assert_locked_object(&sma->sem_perm);
2121 list_del(&un->list_id);
2122
2123
2124
2125
2126
2127 list_del_rcu(&un->list_proc);
2128
2129
2130 for (i = 0; i < sma->sem_nsems; i++) {
2131 struct sem *semaphore = &sma->sem_base[i];
2132 if (un->semadj[i]) {
2133 semaphore->semval += un->semadj[i];
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147 if (semaphore->semval < 0)
2148 semaphore->semval = 0;
2149 if (semaphore->semval > SEMVMX)
2150 semaphore->semval = SEMVMX;
2151 semaphore->sempid = task_tgid_vnr(current);
2152 }
2153 }
2154
2155 do_smart_update(sma, NULL, 0, 1, &wake_q);
2156 sem_unlock(sma, -1);
2157 rcu_read_unlock();
2158 wake_up_q(&wake_q);
2159
2160 kfree_rcu(un, rcu);
2161 }
2162 kfree(ulp);
2163}
2164
2165#ifdef CONFIG_PROC_FS
2166static int sysvipc_sem_proc_show(struct seq_file *s, void *it)
2167{
2168 struct user_namespace *user_ns = seq_user_ns(s);
2169 struct sem_array *sma = it;
2170 time_t sem_otime;
2171
2172
2173
2174
2175
2176
2177
2178 complexmode_enter(sma);
2179
2180 sem_otime = get_semotime(sma);
2181
2182 seq_printf(s,
2183 "%10d %10d %4o %10u %5u %5u %5u %5u %10lu %10lu\n",
2184 sma->sem_perm.key,
2185 sma->sem_perm.id,
2186 sma->sem_perm.mode,
2187 sma->sem_nsems,
2188 from_kuid_munged(user_ns, sma->sem_perm.uid),
2189 from_kgid_munged(user_ns, sma->sem_perm.gid),
2190 from_kuid_munged(user_ns, sma->sem_perm.cuid),
2191 from_kgid_munged(user_ns, sma->sem_perm.cgid),
2192 sem_otime,
2193 sma->sem_ctime);
2194
2195 complexmode_tryleave(sma);
2196
2197 return 0;
2198}
2199#endif
2200