sys_generic.c revision 1.37
1 /* $NetBSD: sys_generic.c,v 1.37 1998/06/25 21:17:17 thorpej 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 8.9 (Berkeley) 2/14/95 41 */ 42 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/filedesc.h> 48 #include <sys/ioctl.h> 49 #include <sys/file.h> 50 #include <sys/proc.h> 51 #include <sys/socketvar.h> 52 #include <sys/signalvar.h> 53 #include <sys/uio.h> 54 #include <sys/kernel.h> 55 #include <sys/stat.h> 56 #include <sys/malloc.h> 57 #include <sys/poll.h> 58 #ifdef KTRACE 59 #include <sys/ktrace.h> 60 #endif 61 62 #include <sys/mount.h> 63 #include <sys/syscallargs.h> 64 65 int selscan __P((struct proc *, fd_mask *, fd_mask *, int, register_t *)); 66 int pollscan __P((struct proc *, struct pollfd *, int, register_t *)); 67 68 /* 69 * Read system call. 70 */ 71 /* ARGSUSED */ 72 int 73 sys_read(p, v, retval) 74 struct proc *p; 75 void *v; 76 register_t *retval; 77 { 78 register struct sys_read_args /* { 79 syscallarg(int) fd; 80 syscallarg(void *) buf; 81 syscallarg(size_t) nbyte; 82 } */ *uap = v; 83 int fd = SCARG(uap, fd); 84 register struct file *fp; 85 register struct filedesc *fdp = p->p_fd; 86 struct uio auio; 87 struct iovec aiov; 88 long cnt, error = 0; 89 #ifdef KTRACE 90 struct iovec ktriov; 91 #endif 92 93 if ((u_int)fd >= fdp->fd_nfiles || 94 (fp = fdp->fd_ofiles[fd]) == NULL || 95 (fp->f_flag & FREAD) == 0) 96 return (EBADF); 97 aiov.iov_base = (caddr_t)SCARG(uap, buf); 98 aiov.iov_len = SCARG(uap, nbyte); 99 auio.uio_iov = &aiov; 100 auio.uio_iovcnt = 1; 101 auio.uio_resid = SCARG(uap, nbyte); 102 auio.uio_rw = UIO_READ; 103 auio.uio_segflg = UIO_USERSPACE; 104 auio.uio_procp = p; 105 if (auio.uio_resid < 0) 106 return EINVAL; 107 #ifdef KTRACE 108 /* 109 * if tracing, save a copy of iovec 110 */ 111 if (KTRPOINT(p, KTR_GENIO)) 112 ktriov = aiov; 113 #endif 114 cnt = SCARG(uap, nbyte); 115 error = (*fp->f_ops->fo_read)(fp, &auio, fp->f_cred); 116 if (error) 117 if (auio.uio_resid != cnt && (error == ERESTART || 118 error == EINTR || error == EWOULDBLOCK)) 119 error = 0; 120 cnt -= auio.uio_resid; 121 #ifdef KTRACE 122 if (KTRPOINT(p, KTR_GENIO) && error == 0) 123 ktrgenio(p->p_tracep, fd, UIO_READ, &ktriov, cnt, error); 124 #endif 125 *retval = cnt; 126 return (error); 127 } 128 129 /* 130 * Scatter read system call. 131 */ 132 int 133 sys_readv(p, v, retval) 134 struct proc *p; 135 void *v; 136 register_t *retval; 137 { 138 register struct sys_readv_args /* { 139 syscallarg(int) fd; 140 syscallarg(const struct iovec *) iovp; 141 syscallarg(int) iovcnt; 142 } */ *uap = v; 143 int fd = SCARG(uap, fd); 144 int iovcnt = SCARG(uap, iovcnt); 145 register struct file *fp; 146 register struct filedesc *fdp = p->p_fd; 147 struct uio auio; 148 register struct iovec *iov; 149 struct iovec *needfree; 150 struct iovec aiov[UIO_SMALLIOV]; 151 long i, cnt, error = 0; 152 u_int iovlen; 153 #ifdef KTRACE 154 struct iovec *ktriov = NULL; 155 #endif 156 157 if ((u_int)fd >= fdp->fd_nfiles || 158 (fp = fdp->fd_ofiles[fd]) == NULL || 159 (fp->f_flag & FREAD) == 0) 160 return (EBADF); 161 /* note: can't use iovlen until iovcnt is validated */ 162 iovlen = iovcnt * sizeof (struct iovec); 163 if ((u_int)iovcnt > UIO_SMALLIOV) { 164 if ((u_int)iovcnt > UIO_MAXIOV) 165 return (EINVAL); 166 MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK); 167 needfree = iov; 168 } else { 169 iov = aiov; 170 needfree = NULL; 171 } 172 auio.uio_iov = iov; 173 auio.uio_iovcnt = iovcnt; 174 auio.uio_rw = UIO_READ; 175 auio.uio_segflg = UIO_USERSPACE; 176 auio.uio_procp = p; 177 error = copyin(SCARG(uap, iovp), iov, iovlen); 178 if (error) 179 goto done; 180 auio.uio_resid = 0; 181 for (i = 0; i < iovcnt; i++) { 182 auio.uio_resid += iov->iov_len; 183 if (auio.uio_resid < 0) { 184 error = EINVAL; 185 goto done; 186 } 187 iov++; 188 } 189 #ifdef KTRACE 190 /* 191 * if tracing, save a copy of iovec 192 */ 193 if (KTRPOINT(p, KTR_GENIO)) { 194 MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); 195 bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen); 196 } 197 #endif 198 cnt = auio.uio_resid; 199 error = (*fp->f_ops->fo_read)(fp, &auio, fp->f_cred); 200 if (error) 201 if (auio.uio_resid != cnt && (error == ERESTART || 202 error == EINTR || error == EWOULDBLOCK)) 203 error = 0; 204 cnt -= auio.uio_resid; 205 #ifdef KTRACE 206 if (KTRPOINT(p, KTR_GENIO)) 207 if (error == 0) { 208 ktrgenio(p->p_tracep, fd, UIO_READ, ktriov, cnt, 209 error); 210 FREE(ktriov, M_TEMP); 211 } 212 #endif 213 *retval = cnt; 214 done: 215 if (needfree) 216 FREE(needfree, M_IOV); 217 return (error); 218 } 219 220 /* 221 * Write system call 222 */ 223 int 224 sys_write(p, v, retval) 225 struct proc *p; 226 void *v; 227 register_t *retval; 228 { 229 register struct sys_write_args /* { 230 syscallarg(int) fd; 231 syscallarg(const void *) buf; 232 syscallarg(size_t) nbyte; 233 } */ *uap = v; 234 int fd = SCARG(uap, fd); 235 register struct file *fp; 236 register struct filedesc *fdp = p->p_fd; 237 struct uio auio; 238 struct iovec aiov; 239 long cnt, error = 0; 240 #ifdef KTRACE 241 struct iovec ktriov; 242 #endif 243 244 if ((u_int)fd >= fdp->fd_nfiles || 245 (fp = fdp->fd_ofiles[fd]) == NULL || 246 (fp->f_flag & FWRITE) == 0) 247 return (EBADF); 248 aiov.iov_base = (char *)SCARG(uap, buf); /* XXX kills const */ 249 aiov.iov_len = SCARG(uap, nbyte); 250 auio.uio_iov = &aiov; 251 auio.uio_iovcnt = 1; 252 auio.uio_resid = SCARG(uap, nbyte); 253 auio.uio_rw = UIO_WRITE; 254 auio.uio_segflg = UIO_USERSPACE; 255 auio.uio_procp = p; 256 if (auio.uio_resid < 0) 257 return EINVAL; 258 #ifdef KTRACE 259 /* 260 * if tracing, save a copy of iovec 261 */ 262 if (KTRPOINT(p, KTR_GENIO)) 263 ktriov = aiov; 264 #endif 265 cnt = SCARG(uap, nbyte); 266 error = (*fp->f_ops->fo_write)(fp, &auio, fp->f_cred); 267 if (error) { 268 if (auio.uio_resid != cnt && (error == ERESTART || 269 error == EINTR || error == EWOULDBLOCK)) 270 error = 0; 271 if (error == EPIPE) 272 psignal(p, SIGPIPE); 273 } 274 cnt -= auio.uio_resid; 275 #ifdef KTRACE 276 if (KTRPOINT(p, KTR_GENIO) && error == 0) 277 ktrgenio(p->p_tracep, fd, UIO_WRITE, &ktriov, cnt, error); 278 #endif 279 *retval = cnt; 280 return (error); 281 } 282 283 /* 284 * Gather write system call 285 */ 286 int 287 sys_writev(p, v, retval) 288 struct proc *p; 289 void *v; 290 register_t *retval; 291 { 292 register struct sys_writev_args /* { 293 syscallarg(int) fd; 294 syscallarg(const struct iovec *) iovp; 295 syscallarg(u_int) iovcnt; 296 } */ *uap = v; 297 int fd = SCARG(uap, fd); 298 int iovcnt = SCARG(uap, iovcnt); 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)fd >= fdp->fd_nfiles || 312 (fp = fdp->fd_ofiles[fd]) == NULL || 313 (fp->f_flag & FWRITE) == 0) 314 return (EBADF); 315 /* note: can't use iovlen until iovcnt is validated */ 316 iovlen = iovcnt * sizeof (struct iovec); 317 if ((u_int)iovcnt > UIO_SMALLIOV) { 318 if ((u_int)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 = iovcnt; 328 auio.uio_rw = UIO_WRITE; 329 auio.uio_segflg = UIO_USERSPACE; 330 auio.uio_procp = p; 331 error = copyin(SCARG(uap, iovp), iov, iovlen); 332 if (error) 333 goto done; 334 auio.uio_resid = 0; 335 for (i = 0; i < iovcnt; i++) { 336 auio.uio_resid += iov->iov_len; 337 if (auio.uio_resid < 0) { 338 error = EINVAL; 339 goto done; 340 } 341 iov++; 342 } 343 #ifdef KTRACE 344 /* 345 * if tracing, save a copy of iovec 346 */ 347 if (KTRPOINT(p, KTR_GENIO)) { 348 MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); 349 bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen); 350 } 351 #endif 352 cnt = auio.uio_resid; 353 error = (*fp->f_ops->fo_write)(fp, &auio, fp->f_cred); 354 if (error) { 355 if (auio.uio_resid != cnt && (error == ERESTART || 356 error == EINTR || error == EWOULDBLOCK)) 357 error = 0; 358 if (error == EPIPE) 359 psignal(p, SIGPIPE); 360 } 361 cnt -= auio.uio_resid; 362 #ifdef KTRACE 363 if (KTRPOINT(p, KTR_GENIO)) 364 if (error == 0) { 365 ktrgenio(p->p_tracep, fd, UIO_WRITE, ktriov, cnt, 366 error); 367 FREE(ktriov, M_TEMP); 368 } 369 #endif 370 *retval = cnt; 371 done: 372 if (needfree) 373 FREE(needfree, M_IOV); 374 return (error); 375 } 376 377 /* 378 * Ioctl system call 379 */ 380 /* ARGSUSED */ 381 int 382 sys_ioctl(p, v, retval) 383 struct proc *p; 384 void *v; 385 register_t *retval; 386 { 387 register struct sys_ioctl_args /* { 388 syscallarg(int) fd; 389 syscallarg(u_long) com; 390 syscallarg(caddr_t) data; 391 } */ *uap = v; 392 register struct file *fp; 393 register struct filedesc *fdp; 394 register u_long com; 395 register int error; 396 register u_int size; 397 caddr_t data, memp; 398 int tmp; 399 #define STK_PARAMS 128 400 char stkbuf[STK_PARAMS]; 401 402 fdp = p->p_fd; 403 if ((u_int)SCARG(uap, fd) >= fdp->fd_nfiles || 404 (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL) 405 return (EBADF); 406 407 if ((fp->f_flag & (FREAD | FWRITE)) == 0) 408 return (EBADF); 409 410 switch (com = SCARG(uap, com)) { 411 case FIONCLEX: 412 fdp->fd_ofileflags[SCARG(uap, fd)] &= ~UF_EXCLOSE; 413 return (0); 414 case FIOCLEX: 415 fdp->fd_ofileflags[SCARG(uap, fd)] |= UF_EXCLOSE; 416 return (0); 417 } 418 419 /* 420 * Interpret high order word to find amount of data to be 421 * copied to/from the user's address space. 422 */ 423 size = IOCPARM_LEN(com); 424 if (size > IOCPARM_MAX) 425 return (ENOTTY); 426 memp = NULL; 427 if (size > sizeof (stkbuf)) { 428 memp = (caddr_t)malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 429 data = memp; 430 } else 431 data = stkbuf; 432 if (com&IOC_IN) { 433 if (size) { 434 error = copyin(SCARG(uap, data), data, size); 435 if (error) { 436 if (memp) 437 free(memp, M_IOCTLOPS); 438 return (error); 439 } 440 } else 441 *(caddr_t *)data = SCARG(uap, data); 442 } else if ((com&IOC_OUT) && size) 443 /* 444 * Zero the buffer so the user always 445 * gets back something deterministic. 446 */ 447 bzero(data, size); 448 else if (com&IOC_VOID) 449 *(caddr_t *)data = SCARG(uap, data); 450 451 switch (com) { 452 453 case FIONBIO: 454 if ((tmp = *(int *)data) != 0) 455 fp->f_flag |= FNONBLOCK; 456 else 457 fp->f_flag &= ~FNONBLOCK; 458 error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 459 break; 460 461 case FIOASYNC: 462 if ((tmp = *(int *)data) != 0) 463 fp->f_flag |= FASYNC; 464 else 465 fp->f_flag &= ~FASYNC; 466 error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p); 467 break; 468 469 case FIOSETOWN: 470 tmp = *(int *)data; 471 if (fp->f_type == DTYPE_SOCKET) { 472 ((struct socket *)fp->f_data)->so_pgid = tmp; 473 error = 0; 474 break; 475 } 476 if (tmp <= 0) { 477 tmp = -tmp; 478 } else { 479 struct proc *p1 = pfind(tmp); 480 if (p1 == 0) { 481 error = ESRCH; 482 break; 483 } 484 tmp = p1->p_pgrp->pg_id; 485 } 486 error = (*fp->f_ops->fo_ioctl) 487 (fp, TIOCSPGRP, (caddr_t)&tmp, p); 488 break; 489 490 case FIOGETOWN: 491 if (fp->f_type == DTYPE_SOCKET) { 492 error = 0; 493 *(int *)data = ((struct socket *)fp->f_data)->so_pgid; 494 break; 495 } 496 error = (*fp->f_ops->fo_ioctl)(fp, TIOCGPGRP, data, p); 497 *(int *)data = -*(int *)data; 498 break; 499 500 default: 501 error = (*fp->f_ops->fo_ioctl)(fp, com, data, p); 502 /* 503 * Copy any data to user, size was 504 * already set and checked above. 505 */ 506 if (error == 0 && (com&IOC_OUT) && size) 507 error = copyout(data, SCARG(uap, data), size); 508 break; 509 } 510 if (memp) 511 free(memp, M_IOCTLOPS); 512 return (error); 513 } 514 515 int selwait, nselcoll; 516 517 /* 518 * Select system call. 519 */ 520 int 521 sys_select(p, v, retval) 522 register struct proc *p; 523 void *v; 524 register_t *retval; 525 { 526 register struct sys_select_args /* { 527 syscallarg(int) nd; 528 syscallarg(fd_set *) in; 529 syscallarg(fd_set *) ou; 530 syscallarg(fd_set *) ex; 531 syscallarg(struct timeval *) tv; 532 } */ *uap = v; 533 caddr_t bits; 534 char smallbits[howmany(FD_SETSIZE, NFDBITS) * sizeof(fd_mask) * 6]; 535 struct timeval atv; 536 int s, ncoll, error = 0, timo; 537 size_t ni; 538 539 if (SCARG(uap, nd) < 0) 540 return (EINVAL); 541 if (SCARG(uap, nd) > p->p_fd->fd_nfiles) { 542 /* forgiving; slightly wrong */ 543 SCARG(uap, nd) = p->p_fd->fd_nfiles; 544 } 545 ni = howmany(SCARG(uap, nd), NFDBITS) * sizeof(fd_mask); 546 if (ni * 6 > sizeof(smallbits)) 547 bits = malloc(ni * 6, M_TEMP, M_WAITOK); 548 else 549 bits = smallbits; 550 551 #define getbits(name, x) \ 552 if (SCARG(uap, name)) { \ 553 error = copyin(SCARG(uap, name), bits + ni * x, ni); \ 554 if (error) \ 555 goto done; \ 556 } else \ 557 bzero(bits + ni * x, ni); 558 getbits(in, 0); 559 getbits(ou, 1); 560 getbits(ex, 2); 561 #undef getbits 562 563 if (SCARG(uap, tv)) { 564 error = copyin(SCARG(uap, tv), (caddr_t)&atv, 565 sizeof (atv)); 566 if (error) 567 goto done; 568 if (itimerfix(&atv)) { 569 error = EINVAL; 570 goto done; 571 } 572 s = splclock(); 573 timeradd(&atv, &time, &atv); 574 timo = hzto(&atv); 575 /* 576 * Avoid inadvertently sleeping forever. 577 */ 578 if (timo == 0) 579 timo = 1; 580 splx(s); 581 } else 582 timo = 0; 583 retry: 584 ncoll = nselcoll; 585 p->p_flag |= P_SELECT; 586 error = selscan(p, (fd_mask *)(bits + ni * 0), 587 (fd_mask *)(bits + ni * 3), SCARG(uap, nd), retval); 588 if (error || *retval) 589 goto done; 590 s = splhigh(); 591 if (timo && timercmp(&time, &atv, >=)) { 592 splx(s); 593 goto done; 594 } 595 if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { 596 splx(s); 597 goto retry; 598 } 599 p->p_flag &= ~P_SELECT; 600 error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo); 601 splx(s); 602 if (error == 0) 603 goto retry; 604 done: 605 p->p_flag &= ~P_SELECT; 606 /* select is not restarted after signals... */ 607 if (error == ERESTART) 608 error = EINTR; 609 if (error == EWOULDBLOCK) 610 error = 0; 611 if (error == 0) { 612 #define putbits(name, x) \ 613 if (SCARG(uap, name)) { \ 614 error = copyout(bits + ni * x, SCARG(uap, name), ni); \ 615 if (error) \ 616 goto out; \ 617 } 618 putbits(in, 3); 619 putbits(ou, 4); 620 putbits(ex, 5); 621 #undef putbits 622 } 623 out: 624 if (ni * 6 > sizeof(smallbits)) 625 free(bits, M_TEMP); 626 return (error); 627 } 628 629 int 630 selscan(p, ibitp, obitp, nfd, retval) 631 struct proc *p; 632 fd_mask *ibitp, *obitp; 633 int nfd; 634 register_t *retval; 635 { 636 register struct filedesc *fdp = p->p_fd; 637 register int msk, i, j, fd; 638 register fd_mask ibits, obits; 639 struct file *fp; 640 int n = 0; 641 static int flag[3] = { POLLRDNORM | POLLHUP | POLLERR, 642 POLLWRNORM | POLLHUP | POLLERR, 643 POLLRDBAND }; 644 645 for (msk = 0; msk < 3; msk++) { 646 for (i = 0; i < nfd; i += NFDBITS) { 647 ibits = *ibitp++; 648 obits = 0; 649 while ((j = ffs(ibits)) && (fd = i + --j) < nfd) { 650 ibits &= ~(1 << j); 651 fp = fdp->fd_ofiles[fd]; 652 if (fp == NULL) 653 return (EBADF); 654 if ((*fp->f_ops->fo_poll)(fp, flag[msk], p)) { 655 obits |= (1 << j); 656 n++; 657 } 658 } 659 *obitp++ = obits; 660 } 661 } 662 *retval = n; 663 return (0); 664 } 665 666 /* 667 * Poll system call. 668 */ 669 int 670 sys_poll(p, v, retval) 671 register struct proc *p; 672 void *v; 673 register_t *retval; 674 { 675 register struct sys_poll_args /* { 676 syscallarg(struct pollfd *) fds; 677 syscallarg(u_int) nfds; 678 syscallarg(int) timeout; 679 } */ *uap = v; 680 caddr_t bits; 681 char smallbits[32 * sizeof(struct pollfd)]; 682 struct timeval atv; 683 int s, ncoll, error = 0, timo; 684 size_t ni; 685 686 if (SCARG(uap, nfds) > p->p_fd->fd_nfiles) { 687 /* forgiving; slightly wrong */ 688 SCARG(uap, nfds) = p->p_fd->fd_nfiles; 689 } 690 ni = SCARG(uap, nfds) * sizeof(struct pollfd); 691 if (ni > sizeof(smallbits)) 692 bits = malloc(ni, M_TEMP, M_WAITOK); 693 else 694 bits = smallbits; 695 696 error = copyin(SCARG(uap, fds), bits, ni); 697 if (error) 698 goto done; 699 700 if (SCARG(uap, timeout) != INFTIM) { 701 atv.tv_sec = SCARG(uap, timeout) / 1000; 702 atv.tv_usec = (SCARG(uap, timeout) % 1000) * 1000; 703 if (itimerfix(&atv)) { 704 error = EINVAL; 705 goto done; 706 } 707 s = splclock(); 708 timeradd(&atv, &time, &atv); 709 timo = hzto(&atv); 710 /* 711 * Avoid inadvertently sleeping forever. 712 */ 713 if (timo == 0) 714 timo = 1; 715 splx(s); 716 } else 717 timo = 0; 718 retry: 719 ncoll = nselcoll; 720 p->p_flag |= P_SELECT; 721 error = pollscan(p, (struct pollfd *)bits, SCARG(uap, nfds), retval); 722 if (error || *retval) 723 goto done; 724 s = splhigh(); 725 if (timo && timercmp(&time, &atv, >=)) { 726 splx(s); 727 goto done; 728 } 729 if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { 730 splx(s); 731 goto retry; 732 } 733 p->p_flag &= ~P_SELECT; 734 error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo); 735 splx(s); 736 if (error == 0) 737 goto retry; 738 done: 739 p->p_flag &= ~P_SELECT; 740 /* poll is not restarted after signals... */ 741 if (error == ERESTART) 742 error = EINTR; 743 if (error == EWOULDBLOCK) 744 error = 0; 745 if (error == 0) { 746 error = copyout(bits, SCARG(uap, fds), ni); 747 if (error) 748 goto out; 749 } 750 out: 751 if (ni > sizeof(smallbits)) 752 free(bits, M_TEMP); 753 return (error); 754 } 755 756 int 757 pollscan(p, fds, nfd, retval) 758 struct proc *p; 759 struct pollfd *fds; 760 int nfd; 761 register_t *retval; 762 { 763 register struct filedesc *fdp = p->p_fd; 764 int i; 765 struct file *fp; 766 int n = 0; 767 768 for (i = 0; i < nfd; i++, fds++) { 769 if ((u_int)fds->fd >= fdp->fd_nfiles) { 770 fds->revents = POLLNVAL; 771 n++; 772 } else { 773 fp = fdp->fd_ofiles[fds->fd]; 774 if (fp == 0) { 775 fds->revents = POLLNVAL; 776 n++; 777 } else { 778 fds->revents = (*fp->f_ops->fo_poll)(fp, 779 fds->events | POLLERR | POLLHUP, p); 780 if (fds->revents != 0) 781 n++; 782 } 783 } 784 } 785 *retval = n; 786 return (0); 787 } 788 789 /*ARGSUSED*/ 790 int 791 seltrue(dev, events, p) 792 dev_t dev; 793 int events; 794 struct proc *p; 795 { 796 797 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 798 } 799 800 /* 801 * Record a select request. 802 */ 803 void 804 selrecord(selector, sip) 805 struct proc *selector; 806 struct selinfo *sip; 807 { 808 struct proc *p; 809 pid_t mypid; 810 811 mypid = selector->p_pid; 812 if (sip->si_pid == mypid) 813 return; 814 if (sip->si_pid && (p = pfind(sip->si_pid)) && 815 p->p_wchan == (caddr_t)&selwait) 816 sip->si_flags |= SI_COLL; 817 else 818 sip->si_pid = mypid; 819 } 820 821 /* 822 * Do a wakeup when a selectable event occurs. 823 */ 824 void 825 selwakeup(sip) 826 register struct selinfo *sip; 827 { 828 register struct proc *p; 829 int s; 830 831 if (sip->si_pid == 0) 832 return; 833 if (sip->si_flags & SI_COLL) { 834 nselcoll++; 835 sip->si_flags &= ~SI_COLL; 836 wakeup((caddr_t)&selwait); 837 } 838 p = pfind(sip->si_pid); 839 sip->si_pid = 0; 840 if (p != NULL) { 841 s = splhigh(); 842 if (p->p_wchan == (caddr_t)&selwait) { 843 if (p->p_stat == SSLEEP) 844 setrunnable(p); 845 else 846 unsleep(p); 847 } else if (p->p_flag & P_SELECT) 848 p->p_flag &= ~P_SELECT; 849 splx(s); 850 } 851 } 852
Indexes created Mon Sep 22 10:09:38 GMT 2025