sys_generic.c revision 1.26
1 /* $NetBSD: sys_generic.c,v 1.26 1996/06/13 05:08:47 cgd Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)sys_generic.c 8.5 (Berkeley) 1/21/94 41 */ 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/filedesc.h> 46 #include <sys/ioctl.h> 47 #include <sys/file.h> 48 #include <sys/proc.h> 49 #include <sys/socketvar.h> 50 #include <sys/signalvar.h> 51 #include <sys/uio.h> 52 #include <sys/kernel.h> 53 #include <sys/stat.h> 54 #include <sys/malloc.h> 55 #ifdef KTRACE 56 #include <sys/ktrace.h> 57 #endif 58 59 #include <sys/mount.h> 60 #include <sys/syscallargs.h> 61 62 int selscan __P((struct proc *, fd_mask *, fd_mask *, int, register_t *)); 63 int seltrue __P((dev_t, int, struct proc *)); 64 65 /* 66 * Read system call. 67 */ 68 /* ARGSUSED */ 69 int 70 sys_read(p, v, retval) 71 struct proc *p; 72 void *v; 73 register_t *retval; 74 { 75 register struct sys_read_args /* { 76 syscallarg(int) fd; 77 syscallarg(char *) buf; 78 syscallarg(u_int) nbyte; 79 } */ *uap = v; 80 register struct file *fp; 81 register struct filedesc *fdp = p->p_fd; 82 struct uio auio; 83 struct iovec aiov; 84 long cnt, error = 0; 85 #ifdef KTRACE 86 struct iovec ktriov; 87 #endif 88 89 if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles || 90 (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL || 91 (fp->f_flag & FREAD) == 0) 92 return (EBADF); 93 aiov.iov_base = (caddr_t)SCARG(uap, buf); 94 aiov.iov_len = SCARG(uap, nbyte); 95 auio.uio_iov = &aiov; 96 auio.uio_iovcnt = 1; 97 auio.uio_resid = SCARG(uap, nbyte); 98 auio.uio_rw = UIO_READ; 99 auio.uio_segflg = UIO_USERSPACE; 100 auio.uio_procp = p; 101 if (auio.uio_resid < 0) 102 return EINVAL; 103 #ifdef KTRACE 104 /* 105 * if tracing, save a copy of iovec 106 */ 107 if (KTRPOINT(p, KTR_GENIO)) 108 ktriov = aiov; 109 #endif 110 cnt = SCARG(uap, nbyte); 111 error = (*fp->f_ops->fo_read)(fp, &auio, fp->f_cred); 112 if (error) 113 if (auio.uio_resid != cnt && (error == ERESTART || 114 error == EINTR || error == EWOULDBLOCK)) 115 error = 0; 116 cnt -= auio.uio_resid; 117 #ifdef KTRACE 118 if (KTRPOINT(p, KTR_GENIO) && error == 0) 119 ktrgenio(p->p_tracep, SCARG(uap, fd), UIO_READ, &ktriov, 120 cnt, error); 121 #endif 122 *retval = cnt; 123 return (error); 124 } 125 126 /* 127 * Scatter read system call. 128 */ 129 int 130 sys_readv(p, v, retval) 131 struct proc *p; 132 void *v; 133 register_t *retval; 134 { 135 register struct sys_readv_args /* { 136 syscallarg(int) fd; 137 syscallarg(struct iovec *) iovp; 138 syscallarg(u_int) iovcnt; 139 } */ *uap = v; 140 register struct file *fp; 141 register struct filedesc *fdp = p->p_fd; 142 struct uio auio; 143 register struct iovec *iov; 144 struct iovec *needfree; 145 struct iovec aiov[UIO_SMALLIOV]; 146 long i, cnt, error = 0; 147 u_int iovlen; 148 #ifdef KTRACE 149 struct iovec *ktriov = NULL; 150 #endif 151 152 if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles || 153 (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL || 154 (fp->f_flag & FREAD) == 0) 155 return (EBADF); 156 /* note: can't use iovlen until iovcnt is validated */ 157 iovlen = SCARG(uap, iovcnt) * sizeof (struct iovec); 158 if (SCARG(uap, iovcnt) > UIO_SMALLIOV) { 159 if (SCARG(uap, iovcnt) > UIO_MAXIOV) 160 return (EINVAL); 161 MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK); 162 needfree = iov; 163 } else { 164 iov = aiov; 165 needfree = NULL; 166 } 167 auio.uio_iov = iov; 168 auio.uio_iovcnt = SCARG(uap, iovcnt); 169 auio.uio_rw = UIO_READ; 170 auio.uio_segflg = UIO_USERSPACE; 171 auio.uio_procp = p; 172 error = copyin((caddr_t)SCARG(uap, iovp), (caddr_t)iov, iovlen); 173 if (error) 174 goto done; 175 auio.uio_resid = 0; 176 for (i = 0; i < SCARG(uap, iovcnt); i++) { 177 #if 0 178 /* Cannot happen iov_len is unsigned */ 179 if (iov->iov_len < 0) { 180 error = EINVAL; 181 goto done; 182 } 183 #endif 184 auio.uio_resid += iov->iov_len; 185 if (auio.uio_resid < 0) { 186 error = EINVAL; 187 goto done; 188 } 189 iov++; 190 } 191 #ifdef KTRACE 192 /* 193 * if tracing, save a copy of iovec 194 */ 195 if (KTRPOINT(p, KTR_GENIO)) { 196 MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); 197 bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen); 198 } 199 #endif 200 cnt = auio.uio_resid; 201 error = (*fp->f_ops->fo_read)(fp, &auio, fp->f_cred); 202 if (error) 203 if (auio.uio_resid != cnt && (error == ERESTART || 204 error == EINTR || error == EWOULDBLOCK)) 205 error = 0; 206 cnt -= auio.uio_resid; 207 #ifdef KTRACE 208 if (ktriov != NULL) { 209 if (error == 0) 210 ktrgenio(p->p_tracep, SCARG(uap, fd), UIO_READ, ktriov, 211 cnt, error); 212 FREE(ktriov, M_TEMP); 213 } 214 #endif 215 *retval = cnt; 216 done: 217 if (needfree) 218 FREE(needfree, M_IOV); 219 return (error); 220 } 221 222 /* 223 * Write system call 224 */ 225 int 226 sys_write(p, v, retval) 227 struct proc *p; 228 void *v; 229 register_t *retval; 230 { 231 register struct sys_write_args /* { 232 syscallarg(int) fd; 233 syscallarg(char *) buf; 234 syscallarg(u_int) nbyte; 235 } */ *uap = v; 236 register struct file *fp; 237 register struct filedesc *fdp = p->p_fd; 238 struct uio auio; 239 struct iovec aiov; 240 long cnt, error = 0; 241 #ifdef KTRACE 242 struct iovec ktriov; 243 #endif 244 245 if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles || 246 (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL || 247 (fp->f_flag & FWRITE) == 0) 248 return (EBADF); 249 aiov.iov_base = (caddr_t)SCARG(uap, buf); 250 aiov.iov_len = SCARG(uap, nbyte); 251 auio.uio_iov = &aiov; 252 auio.uio_iovcnt = 1; 253 auio.uio_resid = SCARG(uap, nbyte); 254 auio.uio_rw = UIO_WRITE; 255 auio.uio_segflg = UIO_USERSPACE; 256 auio.uio_procp = p; 257 if (auio.uio_resid < 0) 258 return EINVAL; 259 #ifdef KTRACE 260 /* 261 * if tracing, save a copy of iovec 262 */ 263 if (KTRPOINT(p, KTR_GENIO)) 264 ktriov = aiov; 265 #endif 266 cnt = SCARG(uap, nbyte); 267 error = (*fp->f_ops->fo_write)(fp, &auio, fp->f_cred); 268 if (error) { 269 if (auio.uio_resid != cnt && (error == ERESTART || 270 error == EINTR || error == EWOULDBLOCK)) 271 error = 0; 272 if (error == EPIPE) 273 psignal(p, SIGPIPE); 274 } 275 cnt -= auio.uio_resid; 276 #ifdef KTRACE 277 if (KTRPOINT(p, KTR_GENIO) && error == 0) 278 ktrgenio(p->p_tracep, SCARG(uap, fd), UIO_WRITE, 279 &ktriov, cnt, error); 280 #endif 281 *retval = cnt; 282 return (error); 283 } 284 285 /* 286 * Gather write system call 287 */ 288 int 289 sys_writev(p, v, retval) 290 struct proc *p; 291 void *v; 292 register_t *retval; 293 { 294 register struct sys_writev_args /* { 295 syscallarg(int) fd; 296 syscallarg(struct iovec *) iovp; 297 syscallarg(u_int) iovcnt; 298 } */ *uap = v; 299 register struct file *fp; 300 register struct filedesc *fdp = p->p_fd; 301 struct uio auio; 302 register struct iovec *iov; 303 struct iovec *needfree; 304 struct iovec aiov[UIO_SMALLIOV]; 305 long i, cnt, error = 0; 306 u_int iovlen; 307 #ifdef KTRACE 308 struct iovec *ktriov = NULL; 309 #endif 310 311 if (((u_int)SCARG(uap, fd)) >= fdp->fd_nfiles || 312 (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL || 313 (fp->f_flag & FWRITE) == 0) 314 return (EBADF); 315 /* note: can't use iovlen until iovcnt is validated */ 316 iovlen = SCARG(uap, iovcnt) * sizeof (struct iovec); 317 if (SCARG(uap, iovcnt) > UIO_SMALLIOV) { 318 if (SCARG(uap, iovcnt) > UIO_MAXIOV) 319 return (EINVAL); 320 MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK); 321 needfree = iov; 322 } else { 323 iov = aiov; 324 needfree = NULL; 325 } 326 auio.uio_iov = iov; 327 auio.uio_iovcnt = SCARG(uap, iovcnt); 328 auio.uio_rw = UIO_WRITE; 329 auio.uio_segflg = UIO_USERSPACE; 330 auio.uio_procp = p; 331 error = copyin((caddr_t)SCARG(uap, iovp), (caddr_t)iov, iovlen); 332 if (error) 333 goto done; 334 auio.uio_resid = 0; 335 for (i = 0; i < SCARG(uap, iovcnt); i++) { 336 #if 0 337 /* Cannot happen iov_len is unsigned */ 338 if (iov->iov_len < 0) { 339 error = EINVAL; 340 goto done; 341 } 342 #endif 343 auio.uio_resid += iov->iov_len; 344 if (auio.uio_resid < 0) { 345 error = EINVAL; 346 goto done; 347 } 348 iov++; 349 } 350 #ifdef KTRACE 351 /* 352 * if tracing, save a copy of iovec 353 */ 354 if (KTRPOINT(p, KTR_GENIO)) { 355 MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); 356 bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen); 357 } 358 #endif 359 cnt = auio.uio_resid; 360 error = (*fp->f_ops->fo_write)(fp, &auio, fp->f_cred); 361 if (error) { 362 if (auio.uio_resid != cnt && (error == ERESTART || 363 error == EINTR || error == EWOULDBLOCK)) 364 error = 0; 365 if (error == EPIPE) 366 psignal(p, SIGPIPE); 367 } 368 cnt -= auio.uio_resid; 369 #ifdef KTRACE 370 if (ktriov != NULL) { 371 if (error == 0) 372 ktrgenio(p->p_tracep, SCARG(uap, fd), UIO_WRITE, 373 ktriov, cnt, error); 374 FREE(ktriov, M_TEMP); 375 } 376 #endif 377 *retval = cnt; 378 done: 379 if (needfree) 380 FREE(needfree, M_IOV); 381 return (error); 382 } 383 384 /* 385 * Ioctl system call 386 */ 387 /* ARGSUSED */ 388 int 389 sys_ioctl(p, v, retval) 390 struct proc *p; 391 void *v; 392 register_t *retval; 393 { 394 register struct sys_ioctl_args /* { 395 syscallarg(int) fd; 396 syscallarg(u_long) com; 397 syscallarg(caddr_t) data; 398 } */ *uap = v; 399 register struct file *fp; 400 register struct filedesc *fdp; 401 register u_long com; 402 register int error; 403 register u_int size; 404 caddr_t data, memp; 405 int tmp; 406 #define STK_PARAMS 128 407 char stkbuf[STK_PARAMS]; 408 409 fdp = p->p_fd; 410 if ((u_int)SCARG(uap, fd) >= fdp->fd_nfiles || 411 (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL) 412 return (EBADF); 413 414 if ((fp->f_flag & (FREAD | FWRITE)) == 0) 415 return (EBADF); 416 417 switch (com = SCARG(uap, com)) { 418 case FIONCLEX: 419 fdp->fd_ofileflags[SCARG(uap, fd)] &= ~UF_EXCLOSE; 420 return (0); 421 case FIOCLEX: 422 fdp->fd_ofileflags[SCARG(uap, fd)] |= UF_EXCLOSE; 423 return (0); 424 } 425 426 /* 427 * Interpret high order word to find amount of data to be 428 * copied to/from the user's address space. 429 */ 430 size = IOCPARM_LEN(com); 431 if (size > IOCPARM_MAX) 432 return (ENOTTY); 433 memp = NULL; 434 if (size > sizeof (stkbuf)) { 435 memp = (caddr_t)malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 436 data = memp; 437 } else 438 data = stkbuf; 439 if (com&IOC_IN) { 440 if (size) { 441 error = copyin(SCARG(uap, data), data, (u_int)size); 442 if (error) { 443 if (memp) 444 free(memp, M_IOCTLOPS); 445 return (error); 446 } 447 } else 448 *(caddr_t *)data = SCARG(uap, data); 449 } else if ((com&IOC_OUT) && size) 450 /* 451 * Zero the buffer so the user always 452 * gets back something deterministic. 453 */ 454 bzero(data, size); 455 else if (com&IOC_VOID) 456 *(caddr_t *)data = SCARG(uap, data); 457 458 switch (com) { 459 460 case FIONBIO: 461 if ((tmp = *(int *)data) != 0) 462 fp->f_flag |= FNONBLOCK; 463 else 464 fp->f_flag &= ~FNONBLOCK; 465 error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 466 break; 467 468 case FIOASYNC: 469 if ((tmp = *(int *)data) != 0) 470 fp->f_flag |= FASYNC; 471 else 472 fp->f_flag &= ~FASYNC; 473 error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p); 474 break; 475 476 case FIOSETOWN: 477 tmp = *(int *)data; 478 if (fp->f_type == DTYPE_SOCKET) { 479 ((struct socket *)fp->f_data)->so_pgid = tmp; 480 error = 0; 481 break; 482 } 483 if (tmp <= 0) { 484 tmp = -tmp; 485 } else { 486 struct proc *p1 = pfind(tmp); 487 if (p1 == 0) { 488 error = ESRCH; 489 break; 490 } 491 tmp = p1->p_pgrp->pg_id; 492 } 493 error = (*fp->f_ops->fo_ioctl) 494 (fp, TIOCSPGRP, (caddr_t)&tmp, p); 495 break; 496 497 case FIOGETOWN: 498 if (fp->f_type == DTYPE_SOCKET) { 499 error = 0; 500 *(int *)data = ((struct socket *)fp->f_data)->so_pgid; 501 break; 502 } 503 error = (*fp->f_ops->fo_ioctl)(fp, TIOCGPGRP, data, p); 504 *(int *)data = -*(int *)data; 505 break; 506 507 default: 508 error = (*fp->f_ops->fo_ioctl)(fp, com, data, p); 509 /* 510 * Copy any data to user, size was 511 * already set and checked above. 512 */ 513 if (error == 0 && (com&IOC_OUT) && size) 514 error = copyout(data, SCARG(uap, data), (u_int)size); 515 break; 516 } 517 if (memp) 518 free(memp, M_IOCTLOPS); 519 return (error); 520 } 521 522 int selwait, nselcoll; 523 524 /* 525 * Select system call. 526 */ 527 int 528 sys_select(p, v, retval) 529 register struct proc *p; 530 void *v; 531 register_t *retval; 532 { 533 register struct sys_select_args /* { 534 syscallarg(u_int) nd; 535 syscallarg(fd_set *) in; 536 syscallarg(fd_set *) ou; 537 syscallarg(fd_set *) ex; 538 syscallarg(struct timeval *) tv; 539 } */ *uap = v; 540 caddr_t bits; 541 char smallbits[howmany(FD_SETSIZE, NFDBITS) * sizeof(fd_mask) * 6]; 542 struct timeval atv; 543 int s, ncoll, error = 0, timo; 544 u_int ni; 545 546 if (SCARG(uap, nd) > p->p_fd->fd_nfiles) { 547 /* forgiving; slightly wrong */ 548 SCARG(uap, nd) = p->p_fd->fd_nfiles; 549 } 550 ni = howmany(SCARG(uap, nd), NFDBITS) * sizeof(fd_mask); 551 if (SCARG(uap, nd) > FD_SETSIZE) 552 bits = malloc(ni * 6, M_TEMP, M_WAITOK); 553 else 554 bits = smallbits; 555 556 #define getbits(name, x) \ 557 if (SCARG(uap, name)) { \ 558 error = copyin((caddr_t)SCARG(uap, name), bits + ni * x, ni); \ 559 if (error) \ 560 goto done; \ 561 } else \ 562 bzero(bits + ni * x, ni); 563 getbits(in, 0); 564 getbits(ou, 1); 565 getbits(ex, 2); 566 #undef getbits 567 568 if (SCARG(uap, tv)) { 569 error = copyin((caddr_t)SCARG(uap, tv), (caddr_t)&atv, 570 sizeof (atv)); 571 if (error) 572 goto done; 573 if (itimerfix(&atv)) { 574 error = EINVAL; 575 goto done; 576 } 577 s = splclock(); 578 timeradd(&atv, &time, &atv); 579 timo = hzto(&atv); 580 /* 581 * Avoid inadvertently sleeping forever. 582 */ 583 if (timo == 0) 584 timo = 1; 585 splx(s); 586 } else 587 timo = 0; 588 retry: 589 ncoll = nselcoll; 590 p->p_flag |= P_SELECT; 591 error = selscan(p, (fd_mask *)(bits + ni * 0), 592 (fd_mask *)(bits + ni * 3), SCARG(uap, nd), retval); 593 if (error || *retval) 594 goto done; 595 s = splhigh(); 596 /* this should be timercmp(&time, &atv, >=) */ 597 if (SCARG(uap, tv) && (time.tv_sec > atv.tv_sec || 598 (time.tv_sec == atv.tv_sec && time.tv_usec >= atv.tv_usec))) { 599 splx(s); 600 goto done; 601 } 602 if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { 603 splx(s); 604 goto retry; 605 } 606 p->p_flag &= ~P_SELECT; 607 error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo); 608 splx(s); 609 if (error == 0) 610 goto retry; 611 done: 612 p->p_flag &= ~P_SELECT; 613 /* select is not restarted after signals... */ 614 if (error == ERESTART) 615 error = EINTR; 616 if (error == EWOULDBLOCK) 617 error = 0; 618 #define putbits(name, x) \ 619 if (SCARG(uap, name) && (error2 = copyout(bits + ni * x, \ 620 (caddr_t)SCARG(uap, name), ni))) \ 621 error = error2; 622 if (error == 0) { 623 int error2; 624 625 putbits(in, 3); 626 putbits(ou, 4); 627 putbits(ex, 5); 628 #undef putbits 629 } 630 if (SCARG(uap, nd) > FD_SETSIZE) 631 free(bits, M_TEMP); 632 return (error); 633 } 634 635 int 636 selscan(p, ibitp, obitp, nfd, retval) 637 struct proc *p; 638 fd_mask *ibitp, *obitp; 639 int nfd; 640 register_t *retval; 641 { 642 register struct filedesc *fdp = p->p_fd; 643 register int msk, i, j, fd; 644 register fd_mask ibits, obits; 645 struct file *fp; 646 int n = 0; 647 static int flag[3] = { FREAD, FWRITE, 0 }; 648 649 for (msk = 0; msk < 3; msk++) { 650 for (i = 0; i < nfd; i += NFDBITS) { 651 ibits = *ibitp++; 652 obits = 0; 653 while ((j = ffs(ibits)) && (fd = i + --j) < nfd) { 654 ibits &= ~(1 << j); 655 fp = fdp->fd_ofiles[fd]; 656 if (fp == NULL) 657 return (EBADF); 658 if ((*fp->f_ops->fo_select)(fp, flag[msk], p)) { 659 obits |= (1 << j); 660 n++; 661 } 662 } 663 *obitp++ = obits; 664 } 665 } 666 *retval = n; 667 return (0); 668 } 669 670 /*ARGSUSED*/ 671 int 672 seltrue(dev, flag, p) 673 dev_t dev; 674 int flag; 675 struct proc *p; 676 { 677 678 return (1); 679 } 680 681 /* 682 * Record a select request. 683 */ 684 void 685 selrecord(selector, sip) 686 struct proc *selector; 687 struct selinfo *sip; 688 { 689 struct proc *p; 690 pid_t mypid; 691 692 mypid = selector->p_pid; 693 if (sip->si_pid == mypid) 694 return; 695 if (sip->si_pid && (p = pfind(sip->si_pid)) && 696 p->p_wchan == (caddr_t)&selwait) 697 sip->si_flags |= SI_COLL; 698 else 699 sip->si_pid = mypid; 700 } 701 702 /* 703 * Do a wakeup when a selectable event occurs. 704 */ 705 void 706 selwakeup(sip) 707 register struct selinfo *sip; 708 { 709 register struct proc *p; 710 int s; 711 712 if (sip->si_pid == 0) 713 return; 714 if (sip->si_flags & SI_COLL) { 715 nselcoll++; 716 sip->si_flags &= ~SI_COLL; 717 wakeup((caddr_t)&selwait); 718 } 719 p = pfind(sip->si_pid); 720 sip->si_pid = 0; 721 if (p != NULL) { 722 s = splhigh(); 723 if (p->p_wchan == (caddr_t)&selwait) { 724 if (p->p_stat == SSLEEP) 725 setrunnable(p); 726 else 727 unsleep(p); 728 } else if (p->p_flag & P_SELECT) 729 p->p_flag &= ~P_SELECT; 730 splx(s); 731 } 732 } 733
Indexes created Mon Sep 22 10:09:38 GMT 2025