/* $OpenBSD: sysv_sem.c,v 1.42 2012/01/10 23:12:13 bluhm Exp $ */ /* $NetBSD: sysv_sem.c,v 1.26 1996/02/09 19:00:25 christos Exp $ */ /* * Copyright (c) 2002,2003 Todd C. Miller * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * * Sponsored in part by the Defense Advanced Research Projects * Agency (DARPA) and Air Force Research Laboratory, Air Force * Materiel Command, USAF, under agreement number F39502-99-1-0512. */ /* * Implementation of SVID semaphores * * Author: Daniel Boulet * * This software is provided ``AS IS'' without any warranties of any kind. */ #include #include #include #include #include #include #include #include #include #include #ifdef SEM_DEBUG #define DPRINTF(x) printf x #else #define DPRINTF(x) #endif int semtot = 0; int semutot = 0; struct semid_ds **sema; /* semaphore id list */ SLIST_HEAD(, sem_undo) semu_list; /* list of undo structures */ struct pool sema_pool; /* pool for struct semid_ds */ struct pool semu_pool; /* pool for struct sem_undo (SEMUSZ) */ unsigned short *semseqs; /* array of sem sequence numbers */ struct sem_undo *semu_alloc(struct process *); int semundo_adjust(struct proc *, struct sem_undo **, int, int, int); void semundo_clear(int, int); void seminit(void) { pool_init(&sema_pool, sizeof(struct semid_ds), 0, 0, 0, "semapl", &pool_allocator_nointr); pool_init(&semu_pool, SEMUSZ, 0, 0, 0, "semupl", &pool_allocator_nointr); sema = malloc(seminfo.semmni * sizeof(struct semid_ds *), M_SEM, M_WAITOK|M_ZERO); semseqs = malloc(seminfo.semmni * sizeof(unsigned short), M_SEM, M_WAITOK|M_ZERO); SLIST_INIT(&semu_list); } /* * Allocate a new sem_undo structure for a process * (returns ptr to structure or NULL if no more room) */ struct sem_undo * semu_alloc(struct process *pr) { struct sem_undo *suptr, *sutmp; if (semutot == seminfo.semmnu) return (NULL); /* no space */ /* * Allocate a semu w/o waiting if possible. * If we do have to wait, we must check to verify that a semu * with un_proc == pr has not been allocated in the meantime. */ semutot++; if ((suptr = pool_get(&semu_pool, PR_NOWAIT)) == NULL) { sutmp = pool_get(&semu_pool, PR_WAITOK); SLIST_FOREACH(suptr, &semu_list, un_next) { if (suptr->un_proc == pr) { pool_put(&semu_pool, sutmp); semutot--; return (suptr); } } suptr = sutmp; } suptr->un_cnt = 0; suptr->un_proc = pr; SLIST_INSERT_HEAD(&semu_list, suptr, un_next); return (suptr); } /* * Adjust a particular entry for a particular proc */ int semundo_adjust(struct proc *p, struct sem_undo **supptr, int semid, int semnum, int adjval) { struct process *pr = p->p_p; struct sem_undo *suptr; struct undo *sunptr; int i; /* * Look for and remember the sem_undo if the caller doesn't provide it. */ suptr = *supptr; if (suptr == NULL) { SLIST_FOREACH(suptr, &semu_list, un_next) { if (suptr->un_proc == pr) { *supptr = suptr; break; } } if (suptr == NULL) { if (adjval == 0) return (0); suptr = semu_alloc(p->p_p); if (suptr == NULL) return (ENOSPC); *supptr = suptr; } } /* * Look for the requested entry and adjust it * (delete if adjval becomes 0). */ sunptr = &suptr->un_ent[0]; for (i = 0; i < suptr->un_cnt; i++, sunptr++) { if (sunptr->un_id != semid || sunptr->un_num != semnum) continue; if (adjval == 0) sunptr->un_adjval = 0; else sunptr->un_adjval += adjval; if (sunptr->un_adjval != 0) return (0); if (--suptr->un_cnt == 0) { SLIST_REMOVE(&semu_list, suptr, sem_undo, un_next); pool_put(&semu_pool, suptr); semutot--; } else if (i < suptr->un_cnt) suptr->un_ent[i] = suptr->un_ent[suptr->un_cnt]; return (0); } /* Didn't find the right entry - create it */ if (adjval == 0) return (0); if (suptr->un_cnt == SEMUME) return (EINVAL); sunptr = &suptr->un_ent[suptr->un_cnt]; suptr->un_cnt++; sunptr->un_adjval = adjval; sunptr->un_id = semid; sunptr->un_num = semnum; return (0); } void semundo_clear(int semid, int semnum) { struct sem_undo *suptr = SLIST_FIRST(&semu_list); struct sem_undo *suprev = SLIST_END(&semu_list); struct undo *sunptr; int i; while (suptr != SLIST_END(&semu_list)) { sunptr = &suptr->un_ent[0]; for (i = 0; i < suptr->un_cnt; i++, sunptr++) { if (sunptr->un_id == semid) { if (semnum == -1 || sunptr->un_num == semnum) { suptr->un_cnt--; if (i < suptr->un_cnt) { suptr->un_ent[i] = suptr->un_ent[suptr->un_cnt]; i--, sunptr--; } } if (semnum != -1) break; } } if (suptr->un_cnt == 0) { struct sem_undo *sutmp = suptr; if (suptr == SLIST_FIRST(&semu_list)) SLIST_REMOVE_HEAD(&semu_list, un_next); else SLIST_REMOVE_NEXT(&semu_list, suprev, un_next); suptr = SLIST_NEXT(suptr, un_next); pool_put(&semu_pool, sutmp); semutot--; } else { suprev = suptr; suptr = SLIST_NEXT(suptr, un_next); } } } int sys___semctl(struct proc *p, void *v, register_t *retval) { struct sys___semctl_args /* { syscallarg(int) semid; syscallarg(int) semnum; syscallarg(int) cmd; syscallarg(union semun *) arg; } */ *uap = v; union semun arg; int error = 0, cmd = SCARG(uap, cmd); switch (cmd) { case IPC_SET: case IPC_STAT: case GETALL: case SETVAL: case SETALL: error = copyin(SCARG(uap, arg), &arg, sizeof(arg)); break; } if (error == 0) { error = semctl1(p, SCARG(uap, semid), SCARG(uap, semnum), cmd, &arg, retval, copyin, copyout); } return (error); } int semctl1(struct proc *p, int semid, int semnum, int cmd, union semun *arg, register_t *retval, int (*ds_copyin)(const void *, void *, size_t), int (*ds_copyout)(const void *, void *, size_t)) { struct ucred *cred = p->p_ucred; int i, ix, error = 0; struct semid_ds sbuf; struct semid_ds *semaptr; unsigned short *semval = NULL; DPRINTF(("call to semctl(%d, %d, %d, %p)\n", semid, semnum, cmd, arg)); ix = IPCID_TO_IX(semid); if (ix < 0 || ix >= seminfo.semmni) return (EINVAL); if ((semaptr = sema[ix]) == NULL || semaptr->sem_perm.seq != IPCID_TO_SEQ(semid)) return (EINVAL); switch (cmd) { case IPC_RMID: if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_M)) != 0) return (error); semaptr->sem_perm.cuid = cred->cr_uid; semaptr->sem_perm.uid = cred->cr_uid; semtot -= semaptr->sem_nsems; free(semaptr->sem_base, M_SEM); pool_put(&sema_pool, semaptr); sema[ix] = NULL; semundo_clear(ix, -1); wakeup(&sema[ix]); break; case IPC_SET: if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_M))) return (error); if ((error = ds_copyin(arg->buf, &sbuf, sizeof(sbuf))) != 0) return (error); semaptr->sem_perm.uid = sbuf.sem_perm.uid; semaptr->sem_perm.gid = sbuf.sem_perm.gid; semaptr->sem_perm.mode = (semaptr->sem_perm.mode & ~0777) | (sbuf.sem_perm.mode & 0777); semaptr->sem_ctime = time_second; break; case IPC_STAT: if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R))) return (error); error = ds_copyout(semaptr, arg->buf, sizeof(struct semid_ds)); break; case GETNCNT: if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R))) return (error); if (semnum < 0 || semnum >= semaptr->sem_nsems) return (EINVAL); *retval = semaptr->sem_base[semnum].semncnt; break; case GETPID: if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R))) return (error); if (semnum < 0 || semnum >= semaptr->sem_nsems) return (EINVAL); *retval = semaptr->sem_base[semnum].sempid; break; case GETVAL: if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R))) return (error); if (semnum < 0 || semnum >= semaptr->sem_nsems) return (EINVAL); *retval = semaptr->sem_base[semnum].semval; break; case GETALL: if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R))) return (error); for (i = 0; i < semaptr->sem_nsems; i++) { error = ds_copyout(&semaptr->sem_base[i].semval, &arg->array[i], sizeof(arg->array[0])); if (error != 0) break; } break; case GETZCNT: if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_R))) return (error); if (semnum < 0 || semnum >= semaptr->sem_nsems) return (EINVAL); *retval = semaptr->sem_base[semnum].semzcnt; break; case SETVAL: if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_W))) return (error); if (semnum < 0 || semnum >= semaptr->sem_nsems) return (EINVAL); if (arg->val > seminfo.semvmx) return (ERANGE); semaptr->sem_base[semnum].semval = arg->val; semundo_clear(ix, semnum); wakeup(&sema[ix]); break; case SETALL: if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_W))) return (error); semval = malloc(semaptr->sem_nsems * sizeof(arg->array[0]), M_TEMP, M_WAITOK); for (i = 0; i < semaptr->sem_nsems; i++) { error = ds_copyin(&arg->array[i], &semval[i], sizeof(arg->array[0])); if (error != 0) goto error; if (semval[i] > seminfo.semvmx) { error = ERANGE; goto error; } } for (i = 0; i < semaptr->sem_nsems; i++) semaptr->sem_base[i].semval = semval[i]; semundo_clear(ix, -1); wakeup(&sema[ix]); break; default: return (EINVAL); } error: if (semval) free(semval, M_TEMP); return (error); } int sys_semget(struct proc *p, void *v, register_t *retval) { struct sys_semget_args /* { syscallarg(key_t) key; syscallarg(int) nsems; syscallarg(int) semflg; } */ *uap = v; int semid, error; int key = SCARG(uap, key); int nsems = SCARG(uap, nsems); int semflg = SCARG(uap, semflg); struct semid_ds *semaptr, *semaptr_new = NULL; struct ucred *cred = p->p_ucred; DPRINTF(("semget(0x%x, %d, 0%o)\n", key, nsems, semflg)); /* * Preallocate space for the new semaphore. If we are going * to sleep, we want to sleep now to eliminate any race * condition in allocating a semaphore with a specific key. */ if (key == IPC_PRIVATE || (semflg & IPC_CREAT)) { if (nsems <= 0 || nsems > seminfo.semmsl) { DPRINTF(("nsems out of range (0<%d<=%d)\n", nsems, seminfo.semmsl)); return (EINVAL); } if (nsems > seminfo.semmns - semtot) { DPRINTF(("not enough semaphores left (need %d, got %d)\n", nsems, seminfo.semmns - semtot)); return (ENOSPC); } semaptr_new = pool_get(&sema_pool, PR_WAITOK); semaptr_new->sem_base = malloc(nsems * sizeof(struct sem), M_SEM, M_WAITOK|M_ZERO); } if (key != IPC_PRIVATE) { for (semid = 0, semaptr = NULL; semid < seminfo.semmni; semid++) { if ((semaptr = sema[semid]) != NULL && semaptr->sem_perm.key == key) { DPRINTF(("found public key\n")); if ((error = ipcperm(cred, &semaptr->sem_perm, semflg & 0700))) goto error; if (nsems > 0 && semaptr->sem_nsems < nsems) { DPRINTF(("too small\n")); error = EINVAL; goto error; } if ((semflg & IPC_CREAT) && (semflg & IPC_EXCL)) { DPRINTF(("not exclusive\n")); error = EEXIST; goto error; } if (semaptr_new != NULL) { free(semaptr_new->sem_base, M_SEM); pool_put(&sema_pool, semaptr_new); } goto found; } } } DPRINTF(("need to allocate the semid_ds\n")); if (key == IPC_PRIVATE || (semflg & IPC_CREAT)) { for (semid = 0; semid < seminfo.semmni; semid++) { if ((semaptr = sema[semid]) == NULL) break; } if (semid == seminfo.semmni) { DPRINTF(("no more semid_ds's available\n")); error = ENOSPC; goto error; } DPRINTF(("semid %d is available\n", semid)); semaptr_new->sem_perm.key = key; semaptr_new->sem_perm.cuid = cred->cr_uid; semaptr_new->sem_perm.uid = cred->cr_uid; semaptr_new->sem_perm.cgid = cred->cr_gid; semaptr_new->sem_perm.gid = cred->cr_gid; semaptr_new->sem_perm.mode = (semflg & 0777); semaptr_new->sem_perm.seq = semseqs[semid] = (semseqs[semid] + 1) & 0x7fff; semaptr_new->sem_nsems = nsems; semaptr_new->sem_otime = 0; semaptr_new->sem_ctime = time_second; sema[semid] = semaptr_new; semtot += nsems; } else { DPRINTF(("didn't find it and wasn't asked to create it\n")); return (ENOENT); } found: *retval = IXSEQ_TO_IPCID(semid, sema[semid]->sem_perm); return (0); error: if (semaptr_new != NULL) { free(semaptr_new->sem_base, M_SEM); pool_put(&sema_pool, semaptr_new); } return (error); } int sys_semop(struct proc *p, void *v, register_t *retval) { struct sys_semop_args /* { syscallarg(int) semid; syscallarg(struct sembuf *) sops; syscallarg(size_t) nsops; } */ *uap = v; #define NSOPS 8 struct sembuf sopbuf[NSOPS]; int semid = SCARG(uap, semid); size_t nsops = SCARG(uap, nsops); struct sembuf *sops; struct semid_ds *semaptr; struct sembuf *sopptr = NULL; struct sem *semptr = NULL; struct sem_undo *suptr = NULL; struct ucred *cred = p->p_ucred; size_t i, j; int do_wakeup, do_undos, error; DPRINTF(("call to semop(%d, %p, %lu)\n", semid, SCARG(uap, sops), (u_long)nsops)); semid = IPCID_TO_IX(semid); /* Convert back to zero origin */ if (semid < 0 || semid >= seminfo.semmni) return (EINVAL); if ((semaptr = sema[semid]) == NULL || semaptr->sem_perm.seq != IPCID_TO_SEQ(SCARG(uap, semid))) return (EINVAL); if ((error = ipcperm(cred, &semaptr->sem_perm, IPC_W))) { DPRINTF(("error = %d from ipaccess\n", error)); return (error); } if (nsops == 0) { *retval = 0; return (0); } else if (nsops > (size_t)seminfo.semopm) { DPRINTF(("too many sops (max=%d, nsops=%lu)\n", seminfo.semopm, (u_long)nsops)); return (E2BIG); } if (nsops <= NSOPS) sops = sopbuf; else sops = malloc(nsops * sizeof(struct sembuf), M_SEM, M_WAITOK); error = copyin(SCARG(uap, sops), sops, nsops * sizeof(struct sembuf)); if (error != 0) { DPRINTF(("error = %d from copyin(%p, %p, %u)\n", error, SCARG(uap, sops), &sops, nsops * sizeof(struct sembuf))); goto done2; } /* * Loop trying to satisfy the vector of requests. * If we reach a point where we must wait, any requests already * performed are rolled back and we go to sleep until some other * process wakes us up. At this point, we start all over again. * * This ensures that from the perspective of other tasks, a set * of requests is atomic (never partially satisfied). */ do_undos = 0; for (;;) { do_wakeup = 0; for (i = 0; i < nsops; i++) { sopptr = &sops[i]; if (sopptr->sem_num >= semaptr->sem_nsems) { error = EFBIG; goto done2; } semptr = &semaptr->sem_base[sopptr->sem_num]; DPRINTF(("semop: semaptr=%x, sem_base=%x, semptr=%x, sem[%d]=%d : op=%d, flag=%s\n", semaptr, semaptr->sem_base, semptr, sopptr->sem_num, semptr->semval, sopptr->sem_op, (sopptr->sem_flg & IPC_NOWAIT) ? "nowait" : "wait")); if (sopptr->sem_op < 0) { if ((int)(semptr->semval + sopptr->sem_op) < 0) { DPRINTF(("semop: can't do it now\n")); break; } else { semptr->semval += sopptr->sem_op; if (semptr->semval == 0 && semptr->semzcnt > 0) do_wakeup = 1; } if (sopptr->sem_flg & SEM_UNDO) do_undos = 1; } else if (sopptr->sem_op == 0) { if (semptr->semval > 0) { DPRINTF(("semop: not zero now\n")); break; } } else { if (semptr->semncnt > 0) do_wakeup = 1; semptr->semval += sopptr->sem_op; if (sopptr->sem_flg & SEM_UNDO) do_undos = 1; } } /* * Did we get through the entire vector? */ if (i >= nsops) goto done; /* * No ... rollback anything that we've already done */ DPRINTF(("semop: rollback 0 through %d\n", i - 1)); for (j = 0; j < i; j++) semaptr->sem_base[sops[j].sem_num].semval -= sops[j].sem_op; /* * If the request that we couldn't satisfy has the * NOWAIT flag set then return with EAGAIN. */ if (sopptr->sem_flg & IPC_NOWAIT) { error = EAGAIN; goto done2; } if (sopptr->sem_op == 0) semptr->semzcnt++; else semptr->semncnt++; DPRINTF(("semop: good night!\n")); error = tsleep(&sema[semid], PLOCK | PCATCH, "semwait", 0); DPRINTF(("semop: good morning (error=%d)!\n", error)); suptr = NULL; /* sem_undo may have been reallocated */ /* * Make sure that the semaphore still exists */ if (sema[semid] == NULL || semaptr->sem_perm.seq != IPCID_TO_SEQ(SCARG(uap, semid))) { error = EIDRM; goto done2; } /* * The semaphore is still alive. Readjust the count of * waiting processes. */ if (sopptr->sem_op == 0) semptr->semzcnt--; else semptr->semncnt--; /* * Is it really morning, or was our sleep interrupted? * (Delayed check of tsleep() return code because we * need to decrement sem[nz]cnt either way.) */ if (error != 0) { error = EINTR; goto done2; } DPRINTF(("semop: good morning!\n")); } done: /* * Process any SEM_UNDO requests. */ if (do_undos) { for (i = 0; i < nsops; i++) { /* * We only need to deal with SEM_UNDO's for non-zero * op's. */ int adjval; if ((sops[i].sem_flg & SEM_UNDO) == 0) continue; adjval = sops[i].sem_op; if (adjval == 0) continue; error = semundo_adjust(p, &suptr, semid, sops[i].sem_num, -adjval); if (error == 0) continue; /* * Uh-Oh! We ran out of either sem_undo's or undo's. * Rollback the adjustments to this point and then * rollback the semaphore ups and down so we can return * with an error with all structures restored. We * rollback the undo's in the exact reverse order that * we applied them. This guarantees that we won't run * out of space as we roll things back out. */ if (i != 0) { for (j = i - 1; j >= 0; j--) { if ((sops[j].sem_flg & SEM_UNDO) == 0) continue; adjval = sops[j].sem_op; if (adjval == 0) continue; if (semundo_adjust(p, &suptr, semid, sops[j].sem_num, adjval) != 0) panic("semop - can't undo undos"); } } for (j = 0; j < nsops; j++) semaptr->sem_base[sops[j].sem_num].semval -= sops[j].sem_op; DPRINTF(("error = %d from semundo_adjust\n", error)); goto done2; } /* loop through the sops */ } /* if (do_undos) */ /* We're definitely done - set the sempid's */ for (i = 0; i < nsops; i++) { sopptr = &sops[i]; semptr = &semaptr->sem_base[sopptr->sem_num]; semptr->sempid = p->p_p->ps_mainproc->p_pid; } semaptr->sem_otime = time_second; /* Do a wakeup if any semaphore was up'd. */ if (do_wakeup) { DPRINTF(("semop: doing wakeup\n")); wakeup(&sema[semid]); DPRINTF(("semop: back from wakeup\n")); } DPRINTF(("semop: done\n")); *retval = 0; done2: if (sops != sopbuf) free(sops, M_SEM); return (error); } /* * Go through the undo structures for this process and apply the adjustments to * semaphores. */ void semexit(struct process *pr) { struct sem_undo *suptr; struct sem_undo **supptr; /* * Go through the chain of undo vectors looking for one associated with * this process. Remember the pointer to the pointer to the element * to dequeue it later. */ supptr = &SLIST_FIRST(&semu_list); SLIST_FOREACH(suptr, &semu_list, un_next) { if (suptr->un_proc == pr) break; supptr = &SLIST_NEXT(suptr, un_next); } /* * If there is no undo vector, skip to the end. */ if (suptr == NULL) return; /* * We now have an undo vector for this process. */ DPRINTF(("process @%p has undo structure with %d entries\n", pr, suptr->un_cnt)); /* * If there are any active undo elements then process them. */ if (suptr->un_cnt > 0) { int ix; for (ix = 0; ix < suptr->un_cnt; ix++) { int semid = suptr->un_ent[ix].un_id; int semnum = suptr->un_ent[ix].un_num; int adjval = suptr->un_ent[ix].un_adjval; struct semid_ds *semaptr; if ((semaptr = sema[semid]) == NULL) panic("semexit - semid not allocated"); if (semnum >= semaptr->sem_nsems) panic("semexit - semnum out of range"); DPRINTF(("semexit: %p id=%d num=%d(adj=%d) ; sem=%d\n", suptr->un_proc, suptr->un_ent[ix].un_id, suptr->un_ent[ix].un_num, suptr->un_ent[ix].un_adjval, semaptr->sem_base[semnum].semval)); if (adjval < 0 && semaptr->sem_base[semnum].semval < -adjval) semaptr->sem_base[semnum].semval = 0; else semaptr->sem_base[semnum].semval += adjval; wakeup(&sema[semid]); DPRINTF(("semexit: back from wakeup\n")); } } /* * Deallocate the undo vector. */ DPRINTF(("removing vector\n")); *supptr = SLIST_NEXT(suptr, un_next); pool_put(&semu_pool, suptr); semutot--; } /* * Userland access to struct seminfo. */ int sysctl_sysvsem(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen) { int error, val; struct semid_ds **sema_new; unsigned short *newseqs; if (namelen != 2) { switch (name[0]) { case KERN_SEMINFO_SEMMNI: case KERN_SEMINFO_SEMMNS: case KERN_SEMINFO_SEMMNU: case KERN_SEMINFO_SEMMSL: case KERN_SEMINFO_SEMOPM: case KERN_SEMINFO_SEMUME: case KERN_SEMINFO_SEMUSZ: case KERN_SEMINFO_SEMVMX: case KERN_SEMINFO_SEMAEM: break; default: return (ENOTDIR); /* overloaded */ } } switch (name[0]) { case KERN_SEMINFO_SEMMNI: val = seminfo.semmni; if ((error = sysctl_int(oldp, oldlenp, newp, newlen, &val)) || val == seminfo.semmni) return (error); if (val < seminfo.semmni || val > 0xffff) return (EINVAL); /* Expand semsegs and semseqs arrays */ sema_new = malloc(val * sizeof(struct semid_ds *), M_SEM, M_WAITOK|M_ZERO); bcopy(sema, sema_new, seminfo.semmni * sizeof(struct semid_ds *)); newseqs = malloc(val * sizeof(unsigned short), M_SEM, M_WAITOK|M_ZERO); bcopy(semseqs, newseqs, seminfo.semmni * sizeof(unsigned short)); free(sema, M_SEM); free(semseqs, M_SEM); sema = sema_new; semseqs = newseqs; seminfo.semmni = val; return (0); case KERN_SEMINFO_SEMMNS: val = seminfo.semmns; if ((error = sysctl_int(oldp, oldlenp, newp, newlen, &val)) || val == seminfo.semmns) return (error); if (val < seminfo.semmns || val > 0xffff) return (EINVAL); /* can't decrease semmns */ seminfo.semmns = val; return (0); case KERN_SEMINFO_SEMMNU: val = seminfo.semmnu; if ((error = sysctl_int(oldp, oldlenp, newp, newlen, &val)) || val == seminfo.semmnu) return (error); if (val < seminfo.semmnu) return (EINVAL); /* can't decrease semmnu */ seminfo.semmnu = val; return (0); case KERN_SEMINFO_SEMMSL: val = seminfo.semmsl; if ((error = sysctl_int(oldp, oldlenp, newp, newlen, &val)) || val == seminfo.semmsl) return (error); if (val < seminfo.semmsl || val > 0xffff) return (EINVAL); /* can't decrease semmsl */ seminfo.semmsl = val; return (0); case KERN_SEMINFO_SEMOPM: val = seminfo.semopm; if ((error = sysctl_int(oldp, oldlenp, newp, newlen, &val)) || val == seminfo.semopm) return (error); if (val <= 0) return (EINVAL); /* semopm must be >= 1 */ seminfo.semopm = val; return (0); case KERN_SEMINFO_SEMUME: return (sysctl_rdint(oldp, oldlenp, newp, seminfo.semume)); case KERN_SEMINFO_SEMUSZ: return (sysctl_rdint(oldp, oldlenp, newp, seminfo.semusz)); case KERN_SEMINFO_SEMVMX: return (sysctl_rdint(oldp, oldlenp, newp, seminfo.semvmx)); case KERN_SEMINFO_SEMAEM: return (sysctl_rdint(oldp, oldlenp, newp, seminfo.semaem)); default: return (EOPNOTSUPP); } /* NOTREACHED */ }