| 442 | */ |
| 443 | |
| 444 | static int |
| 445 | semundo_adjust(struct thread *td, struct sem_undo **supptr, int semid, |
| 446 | int semseq, int semnum, int adjval) |
| 447 | { |
| 448 | struct proc *p = td->td_proc; |
| 449 | struct sem_undo *suptr; |
| 450 | struct undo *sunptr; |
| 451 | int i; |
| 452 | |
| 453 | SEMUNDO_LOCKASSERT(MA_OWNED); |
| 454 | /* Look for and remember the sem_undo if the caller doesn't provide |
| 455 | it */ |
| 456 | |
| 457 | suptr = *supptr; |
| 458 | if (suptr == NULL) { |
| 459 | LIST_FOREACH(suptr, &semu_list, un_next) { |
| 460 | if (suptr->un_proc == p) { |
| 461 | *supptr = suptr; |
| 462 | break; |
| 463 | } |
| 464 | } |
| 465 | if (suptr == NULL) { |
| 466 | if (adjval == 0) |
| 467 | return(0); |
| 468 | suptr = semu_alloc(td); |
| 469 | if (suptr == NULL) |
| 470 | return (ENOSPC); |
| 471 | *supptr = suptr; |
| 472 | } |
| 473 | } |
| 474 | |
| 475 | /* |
| 476 | * Look for the requested entry and adjust it (delete if adjval becomes |
| 477 | * 0). |
| 478 | */ |
| 479 | sunptr = &suptr->un_ent[0]; |
| 480 | for (i = 0; i < suptr->un_cnt; i++, sunptr++) { |
| 481 | if (sunptr->un_id != semid || sunptr->un_num != semnum) |
| 482 | continue; |
| 483 | if (adjval != 0) { |
| 484 | adjval += sunptr->un_adjval; |
| 485 | if (adjval > seminfo.semaem || adjval < -seminfo.semaem) |
| 486 | return (ERANGE); |
| 487 | } |
| 488 | sunptr->un_adjval = adjval; |
| 489 | if (sunptr->un_adjval == 0) { |
| 490 | suptr->un_cnt--; |
| 491 | if (i < suptr->un_cnt) |
| 492 | suptr->un_ent[i] = |
| 493 | suptr->un_ent[suptr->un_cnt]; |
| 494 | if (suptr->un_cnt == 0) |
| 495 | semu_try_free(suptr); |
| 496 | } |
| 497 | return (0); |
| 498 | } |
| 499 | |
| 500 | /* Didn't find the right entry - create it */ |
| 501 | if (adjval == 0) |
no test coverage detected