sys_generic.c revision 1.39
1 /* $NetBSD: sys_generic.c,v 1.39 1998/06/30 07:39:23 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 87 if ((u_int)fd >= fdp->fd_nfiles || 88 (fp = fdp->fd_ofiles[fd]) == NULL || 89 (fp->f_flag & FREAD) == 0) 90 return (EBADF); 91 92 return (dofileread(p, fd, fp, SCARG(uap, buf), SCARG(uap, nbyte), 93 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 94 } 95 96 int 97 dofileread(p, fd, fp, buf, nbyte, offset, flags, retval) 98 struct proc *p; 99 int fd; 100 struct file *fp; 101 void *buf; 102 size_t nbyte; 103 off_t *offset; 104 int flags; 105 register_t *retval; 106 { 107 struct uio auio; 108 struct iovec aiov; 109 long cnt, error = 0; 110 #ifdef KTRACE 111 struct iovec ktriov; 112 #endif 113 114 aiov.iov_base = (caddr_t)buf; 115 aiov.iov_len = nbyte; 116 auio.uio_iov = &aiov; 117 auio.uio_iovcnt = 1; 118 auio.uio_resid = nbyte; 119 auio.uio_rw = UIO_READ; 120 auio.uio_segflg = UIO_USERSPACE; 121 auio.uio_procp = p; 122 if (auio.uio_resid < 0) 123 return EINVAL; 124 #ifdef KTRACE 125 /* 126 * if tracing, save a copy of iovec 127 */ 128 if (KTRPOINT(p, KTR_GENIO)) 129 ktriov = aiov; 130 #endif 131 cnt = auio.uio_resid; 132 error = (*fp->f_ops->fo_read)(fp, offset, &auio, fp->f_cred, flags); 133 if (error) 134 if (auio.uio_resid != cnt && (error == ERESTART || 135 error == EINTR || error == EWOULDBLOCK)) 136 error = 0; 137 cnt -= auio.uio_resid; 138 #ifdef KTRACE 139 if (KTRPOINT(p, KTR_GENIO) && error == 0) 140 ktrgenio(p->p_tracep, fd, UIO_READ, &ktriov, cnt, error); 141 #endif 142 *retval = cnt; 143 return (error); 144 } 145 146 /* 147 * Scatter read system call. 148 */ 149 int 150 sys_readv(p, v, retval) 151 struct proc *p; 152 void *v; 153 register_t *retval; 154 { 155 register struct sys_readv_args /* { 156 syscallarg(int) fd; 157 syscallarg(const struct iovec *) iovp; 158 syscallarg(int) iovcnt; 159 } */ *uap = v; 160 int fd = SCARG(uap, fd); 161 register struct file *fp; 162 register struct filedesc *fdp = p->p_fd; 163 164 if ((u_int)fd >= fdp->fd_nfiles || 165 (fp = fdp->fd_ofiles[fd]) == NULL || 166 (fp->f_flag & FREAD) == 0) 167 return (EBADF); 168 169 return (dofilereadv(p, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt), 170 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 171 } 172 173 int 174 dofilereadv(p, fd, fp, iovp, iovcnt, offset, flags, retval) 175 struct proc *p; 176 int fd; 177 struct file *fp; 178 const struct iovec *iovp; 179 int iovcnt; 180 off_t *offset; 181 int flags; 182 register_t *retval; 183 { 184 struct uio auio; 185 register struct iovec *iov; 186 struct iovec *needfree; 187 struct iovec aiov[UIO_SMALLIOV]; 188 long i, cnt, error = 0; 189 u_int iovlen; 190 #ifdef KTRACE 191 struct iovec *ktriov = NULL; 192 #endif 193 194 /* note: can't use iovlen until iovcnt is validated */ 195 iovlen = iovcnt * sizeof (struct iovec); 196 if ((u_int)iovcnt > UIO_SMALLIOV) { 197 if ((u_int)iovcnt > UIO_MAXIOV) 198 return (EINVAL); 199 MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK); 200 needfree = iov; 201 } else { 202 iov = aiov; 203 needfree = NULL; 204 } 205 auio.uio_iov = iov; 206 auio.uio_iovcnt = iovcnt; 207 auio.uio_rw = UIO_READ; 208 auio.uio_segflg = UIO_USERSPACE; 209 auio.uio_procp = p; 210 error = copyin(iovp, iov, iovlen); 211 if (error) 212 goto done; 213 auio.uio_resid = 0; 214 for (i = 0; i < iovcnt; i++) { 215 auio.uio_resid += iov->iov_len; 216 if (auio.uio_resid < 0) { 217 error = EINVAL; 218 goto done; 219 } 220 iov++; 221 } 222 #ifdef KTRACE 223 /* 224 * if tracing, save a copy of iovec 225 */ 226 if (KTRPOINT(p, KTR_GENIO)) { 227 MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); 228 bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen); 229 } 230 #endif 231 cnt = auio.uio_resid; 232 error = (*fp->f_ops->fo_read)(fp, offset, &auio, fp->f_cred, flags); 233 if (error) 234 if (auio.uio_resid != cnt && (error == ERESTART || 235 error == EINTR || error == EWOULDBLOCK)) 236 error = 0; 237 cnt -= auio.uio_resid; 238 #ifdef KTRACE 239 if (KTRPOINT(p, KTR_GENIO)) 240 if (error == 0) { 241 ktrgenio(p->p_tracep, fd, UIO_READ, ktriov, cnt, 242 error); 243 FREE(ktriov, M_TEMP); 244 } 245 #endif 246 *retval = cnt; 247 done: 248 if (needfree) 249 FREE(needfree, M_IOV); 250 return (error); 251 } 252 253 /* 254 * Write system call 255 */ 256 int 257 sys_write(p, v, retval) 258 struct proc *p; 259 void *v; 260 register_t *retval; 261 { 262 register struct sys_write_args /* { 263 syscallarg(int) fd; 264 syscallarg(const void *) buf; 265 syscallarg(size_t) nbyte; 266 } */ *uap = v; 267 int fd = SCARG(uap, fd); 268 register struct file *fp; 269 register struct filedesc *fdp = p->p_fd; 270 271 if ((u_int)fd >= fdp->fd_nfiles || 272 (fp = fdp->fd_ofiles[fd]) == NULL || 273 (fp->f_flag & FWRITE) == 0) 274 return (EBADF); 275 276 return (dofilewrite(p, fd, fp, SCARG(uap, buf), SCARG(uap, nbyte), 277 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 278 } 279 280 int 281 dofilewrite(p, fd, fp, buf, nbyte, offset, flags, retval) 282 struct proc *p; 283 int fd; 284 struct file *fp; 285 const void *buf; 286 size_t nbyte; 287 off_t *offset; 288 int flags; 289 register_t *retval; 290 { 291 struct uio auio; 292 struct iovec aiov; 293 long cnt, error = 0; 294 #ifdef KTRACE 295 struct iovec ktriov; 296 #endif 297 298 aiov.iov_base = (caddr_t)buf; /* XXX kills const */ 299 aiov.iov_len = nbyte; 300 auio.uio_iov = &aiov; 301 auio.uio_iovcnt = 1; 302 auio.uio_resid = nbyte; 303 auio.uio_rw = UIO_WRITE; 304 auio.uio_segflg = UIO_USERSPACE; 305 auio.uio_procp = p; 306 if (auio.uio_resid < 0) 307 return EINVAL; 308 #ifdef KTRACE 309 /* 310 * if tracing, save a copy of iovec 311 */ 312 if (KTRPOINT(p, KTR_GENIO)) 313 ktriov = aiov; 314 #endif 315 cnt = auio.uio_resid; 316 error = (*fp->f_ops->fo_write)(fp, offset, &auio, fp->f_cred, flags); 317 if (error) { 318 if (auio.uio_resid != cnt && (error == ERESTART || 319 error == EINTR || error == EWOULDBLOCK)) 320 error = 0; 321 if (error == EPIPE) 322 psignal(p, SIGPIPE); 323 } 324 cnt -= auio.uio_resid; 325 #ifdef KTRACE 326 if (KTRPOINT(p, KTR_GENIO) && error == 0) 327 ktrgenio(p->p_tracep, fd, UIO_WRITE, &ktriov, cnt, error); 328 #endif 329 *retval = cnt; 330 return (error); 331 } 332 333 /* 334 * Gather write system call 335 */ 336 int 337 sys_writev(p, v, retval) 338 struct proc *p; 339 void *v; 340 register_t *retval; 341 { 342 register struct sys_writev_args /* { 343 syscallarg(int) fd; 344 syscallarg(const struct iovec *) iovp; 345 syscallarg(int) iovcnt; 346 } */ *uap = v; 347 int fd = SCARG(uap, fd); 348 register struct file *fp; 349 register struct filedesc *fdp = p->p_fd; 350 351 if ((u_int)fd >= fdp->fd_nfiles || 352 (fp = fdp->fd_ofiles[fd]) == NULL || 353 (fp->f_flag & FWRITE) == 0) 354 return (EBADF); 355 356 return (dofilewritev(p, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt), 357 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 358 } 359 360 int 361 dofilewritev(p, fd, fp, iovp, iovcnt, offset, flags, retval) 362 struct proc *p; 363 int fd; 364 struct file *fp; 365 const struct iovec *iovp; 366 int iovcnt; 367 off_t *offset; 368 int flags; 369 register_t *retval; 370 { 371 struct uio auio; 372 register struct iovec *iov; 373 struct iovec *needfree; 374 struct iovec aiov[UIO_SMALLIOV]; 375 long i, cnt, error = 0; 376 u_int iovlen; 377 #ifdef KTRACE 378 struct iovec *ktriov = NULL; 379 #endif 380 381 /* note: can't use iovlen until iovcnt is validated */ 382 iovlen = iovcnt * sizeof (struct iovec); 383 if ((u_int)iovcnt > UIO_SMALLIOV) { 384 if ((u_int)iovcnt > UIO_MAXIOV) 385 return (EINVAL); 386 MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK); 387 needfree = iov; 388 } else { 389 iov = aiov; 390 needfree = NULL; 391 } 392 auio.uio_iov = iov; 393 auio.uio_iovcnt = iovcnt; 394 auio.uio_rw = UIO_WRITE; 395 auio.uio_segflg = UIO_USERSPACE; 396 auio.uio_procp = p; 397 error = copyin(iovp, iov, iovlen); 398 if (error) 399 goto done; 400 auio.uio_resid = 0; 401 for (i = 0; i < iovcnt; i++) { 402 auio.uio_resid += iov->iov_len; 403 if (auio.uio_resid < 0) { 404 error = EINVAL; 405 goto done; 406 } 407 iov++; 408 } 409 #ifdef KTRACE 410 /* 411 * if tracing, save a copy of iovec 412 */ 413 if (KTRPOINT(p, KTR_GENIO)) { 414 MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); 415 bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen); 416 } 417 #endif 418 cnt = auio.uio_resid; 419 error = (*fp->f_ops->fo_write)(fp, offset, &auio, fp->f_cred, flags); 420 if (error) { 421 if (auio.uio_resid != cnt && (error == ERESTART || 422 error == EINTR || error == EWOULDBLOCK)) 423 error = 0; 424 if (error == EPIPE) 425 psignal(p, SIGPIPE); 426 } 427 cnt -= auio.uio_resid; 428 #ifdef KTRACE 429 if (KTRPOINT(p, KTR_GENIO)) 430 if (error == 0) { 431 ktrgenio(p->p_tracep, fd, UIO_WRITE, ktriov, cnt, 432 error); 433 FREE(ktriov, M_TEMP); 434 } 435 #endif 436 *retval = cnt; 437 done: 438 if (needfree) 439 FREE(needfree, M_IOV); 440 return (error); 441 } 442 443 /* 444 * Ioctl system call 445 */ 446 /* ARGSUSED */ 447 int 448 sys_ioctl(p, v, retval) 449 struct proc *p; 450 void *v; 451 register_t *retval; 452 { 453 register struct sys_ioctl_args /* { 454 syscallarg(int) fd; 455 syscallarg(u_long) com; 456 syscallarg(caddr_t) data; 457 } */ *uap = v; 458 register struct file *fp; 459 register struct filedesc *fdp; 460 register u_long com; 461 register int error; 462 register u_int size; 463 caddr_t data, memp; 464 int tmp; 465 #define STK_PARAMS 128 466 char stkbuf[STK_PARAMS]; 467 468 fdp = p->p_fd; 469 if ((u_int)SCARG(uap, fd) >= fdp->fd_nfiles || 470 (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL) 471 return (EBADF); 472 473 if ((fp->f_flag & (FREAD | FWRITE)) == 0) 474 return (EBADF); 475 476 switch (com = SCARG(uap, com)) { 477 case FIONCLEX: 478 fdp->fd_ofileflags[SCARG(uap, fd)] &= ~UF_EXCLOSE; 479 return (0); 480 case FIOCLEX: 481 fdp->fd_ofileflags[SCARG(uap, fd)] |= UF_EXCLOSE; 482 return (0); 483 } 484 485 /* 486 * Interpret high order word to find amount of data to be 487 * copied to/from the user's address space. 488 */ 489 size = IOCPARM_LEN(com); 490 if (size > IOCPARM_MAX) 491 return (ENOTTY); 492 memp = NULL; 493 if (size > sizeof (stkbuf)) { 494 memp = (caddr_t)malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 495 data = memp; 496 } else 497 data = stkbuf; 498 if (com&IOC_IN) { 499 if (size) { 500 error = copyin(SCARG(uap, data), data, size); 501 if (error) { 502 if (memp) 503 free(memp, M_IOCTLOPS); 504 return (error); 505 } 506 } else 507 *(caddr_t *)data = SCARG(uap, data); 508 } else if ((com&IOC_OUT) && size) 509 /* 510 * Zero the buffer so the user always 511 * gets back something deterministic. 512 */ 513 bzero(data, size); 514 else if (com&IOC_VOID) 515 *(caddr_t *)data = SCARG(uap, data); 516 517 switch (com) { 518 519 case FIONBIO: 520 if ((tmp = *(int *)data) != 0) 521 fp->f_flag |= FNONBLOCK; 522 else 523 fp->f_flag &= ~FNONBLOCK; 524 error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 525 break; 526 527 case FIOASYNC: 528 if ((tmp = *(int *)data) != 0) 529 fp->f_flag |= FASYNC; 530 else 531 fp->f_flag &= ~FASYNC; 532 error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p); 533 break; 534 535 case FIOSETOWN: 536 tmp = *(int *)data; 537 if (fp->f_type == DTYPE_SOCKET) { 538 ((struct socket *)fp->f_data)->so_pgid = tmp; 539 error = 0; 540 break; 541 } 542 if (tmp <= 0) { 543 tmp = -tmp; 544 } else { 545 struct proc *p1 = pfind(tmp); 546 if (p1 == 0) { 547 error = ESRCH; 548 break; 549 } 550 tmp = p1->p_pgrp->pg_id; 551 } 552 error = (*fp->f_ops->fo_ioctl) 553 (fp, TIOCSPGRP, (caddr_t)&tmp, p); 554 break; 555 556 case FIOGETOWN: 557 if (fp->f_type == DTYPE_SOCKET) { 558 error = 0; 559 *(int *)data = ((struct socket *)fp->f_data)->so_pgid; 560 break; 561 } 562 error = (*fp->f_ops->fo_ioctl)(fp, TIOCGPGRP, data, p); 563 *(int *)data = -*(int *)data; 564 break; 565 566 default: 567 error = (*fp->f_ops->fo_ioctl)(fp, com, data, p); 568 /* 569 * Copy any data to user, size was 570 * already set and checked above. 571 */ 572 if (error == 0 && (com&IOC_OUT) && size) 573 error = copyout(data, SCARG(uap, data), size); 574 break; 575 } 576 if (memp) 577 free(memp, M_IOCTLOPS); 578 return (error); 579 } 580 581 int selwait, nselcoll; 582 583 /* 584 * Select system call. 585 */ 586 int 587 sys_select(p, v, retval) 588 register struct proc *p; 589 void *v; 590 register_t *retval; 591 { 592 register struct sys_select_args /* { 593 syscallarg(int) nd; 594 syscallarg(fd_set *) in; 595 syscallarg(fd_set *) ou; 596 syscallarg(fd_set *) ex; 597 syscallarg(struct timeval *) tv; 598 } */ *uap = v; 599 caddr_t bits; 600 char smallbits[howmany(FD_SETSIZE, NFDBITS) * sizeof(fd_mask) * 6]; 601 struct timeval atv; 602 int s, ncoll, error = 0, timo; 603 size_t ni; 604 605 if (SCARG(uap, nd) < 0) 606 return (EINVAL); 607 if (SCARG(uap, nd) > p->p_fd->fd_nfiles) { 608 /* forgiving; slightly wrong */ 609 SCARG(uap, nd) = p->p_fd->fd_nfiles; 610 } 611 ni = howmany(SCARG(uap, nd), NFDBITS) * sizeof(fd_mask); 612 if (ni * 6 > sizeof(smallbits)) 613 bits = malloc(ni * 6, M_TEMP, M_WAITOK); 614 else 615 bits = smallbits; 616 617 #define getbits(name, x) \ 618 if (SCARG(uap, name)) { \ 619 error = copyin(SCARG(uap, name), bits + ni * x, ni); \ 620 if (error) \ 621 goto done; \ 622 } else \ 623 bzero(bits + ni * x, ni); 624 getbits(in, 0); 625 getbits(ou, 1); 626 getbits(ex, 2); 627 #undef getbits 628 629 if (SCARG(uap, tv)) { 630 error = copyin(SCARG(uap, tv), (caddr_t)&atv, 631 sizeof (atv)); 632 if (error) 633 goto done; 634 if (itimerfix(&atv)) { 635 error = EINVAL; 636 goto done; 637 } 638 s = splclock(); 639 timeradd(&atv, &time, &atv); 640 timo = hzto(&atv); 641 /* 642 * Avoid inadvertently sleeping forever. 643 */ 644 if (timo == 0) 645 timo = 1; 646 splx(s); 647 } else 648 timo = 0; 649 retry: 650 ncoll = nselcoll; 651 p->p_flag |= P_SELECT; 652 error = selscan(p, (fd_mask *)(bits + ni * 0), 653 (fd_mask *)(bits + ni * 3), SCARG(uap, nd), retval); 654 if (error || *retval) 655 goto done; 656 s = splhigh(); 657 if (timo && timercmp(&time, &atv, >=)) { 658 splx(s); 659 goto done; 660 } 661 if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { 662 splx(s); 663 goto retry; 664 } 665 p->p_flag &= ~P_SELECT; 666 error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo); 667 splx(s); 668 if (error == 0) 669 goto retry; 670 done: 671 p->p_flag &= ~P_SELECT; 672 /* select is not restarted after signals... */ 673 if (error == ERESTART) 674 error = EINTR; 675 if (error == EWOULDBLOCK) 676 error = 0; 677 if (error == 0) { 678 #define putbits(name, x) \ 679 if (SCARG(uap, name)) { \ 680 error = copyout(bits + ni * x, SCARG(uap, name), ni); \ 681 if (error) \ 682 goto out; \ 683 } 684 putbits(in, 3); 685 putbits(ou, 4); 686 putbits(ex, 5); 687 #undef putbits 688 } 689 out: 690 if (ni * 6 > sizeof(smallbits)) 691 free(bits, M_TEMP); 692 return (error); 693 } 694 695 int 696 selscan(p, ibitp, obitp, nfd, retval) 697 struct proc *p; 698 fd_mask *ibitp, *obitp; 699 int nfd; 700 register_t *retval; 701 { 702 register struct filedesc *fdp = p->p_fd; 703 register int msk, i, j, fd; 704 register fd_mask ibits, obits; 705 struct file *fp; 706 int n = 0; 707 static int flag[3] = { POLLRDNORM | POLLHUP | POLLERR, 708 POLLWRNORM | POLLHUP | POLLERR, 709 POLLRDBAND }; 710 711 for (msk = 0; msk < 3; msk++) { 712 for (i = 0; i < nfd; i += NFDBITS) { 713 ibits = *ibitp++; 714 obits = 0; 715 while ((j = ffs(ibits)) && (fd = i + --j) < nfd) { 716 ibits &= ~(1 << j); 717 fp = fdp->fd_ofiles[fd]; 718 if (fp == NULL) 719 return (EBADF); 720 if ((*fp->f_ops->fo_poll)(fp, flag[msk], p)) { 721 obits |= (1 << j); 722 n++; 723 } 724 } 725 *obitp++ = obits; 726 } 727 } 728 *retval = n; 729 return (0); 730 } 731 732 /* 733 * Poll system call. 734 */ 735 int 736 sys_poll(p, v, retval) 737 register struct proc *p; 738 void *v; 739 register_t *retval; 740 { 741 register struct sys_poll_args /* { 742 syscallarg(struct pollfd *) fds; 743 syscallarg(u_int) nfds; 744 syscallarg(int) timeout; 745 } */ *uap = v; 746 caddr_t bits; 747 char smallbits[32 * sizeof(struct pollfd)]; 748 struct timeval atv; 749 int s, ncoll, error = 0, timo; 750 size_t ni; 751 752 if (SCARG(uap, nfds) > p->p_fd->fd_nfiles) { 753 /* forgiving; slightly wrong */ 754 SCARG(uap, nfds) = p->p_fd->fd_nfiles; 755 } 756 ni = SCARG(uap, nfds) * sizeof(struct pollfd); 757 if (ni > sizeof(smallbits)) 758 bits = malloc(ni, M_TEMP, M_WAITOK); 759 else 760 bits = smallbits; 761 762 error = copyin(SCARG(uap, fds), bits, ni); 763 if (error) 764 goto done; 765 766 if (SCARG(uap, timeout) != INFTIM) { 767 atv.tv_sec = SCARG(uap, timeout) / 1000; 768 atv.tv_usec = (SCARG(uap, timeout) % 1000) * 1000; 769 if (itimerfix(&atv)) { 770 error = EINVAL; 771 goto done; 772 } 773 s = splclock(); 774 timeradd(&atv, &time, &atv); 775 timo = hzto(&atv); 776 /* 777 * Avoid inadvertently sleeping forever. 778 */ 779 if (timo == 0) 780 timo = 1; 781 splx(s); 782 } else 783 timo = 0; 784 retry: 785 ncoll = nselcoll; 786 p->p_flag |= P_SELECT; 787 error = pollscan(p, (struct pollfd *)bits, SCARG(uap, nfds), retval); 788 if (error || *retval) 789 goto done; 790 s = splhigh(); 791 if (timo && timercmp(&time, &atv, >=)) { 792 splx(s); 793 goto done; 794 } 795 if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { 796 splx(s); 797 goto retry; 798 } 799 p->p_flag &= ~P_SELECT; 800 error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo); 801 splx(s); 802 if (error == 0) 803 goto retry; 804 done: 805 p->p_flag &= ~P_SELECT; 806 /* poll is not restarted after signals... */ 807 if (error == ERESTART) 808 error = EINTR; 809 if (error == EWOULDBLOCK) 810 error = 0; 811 if (error == 0) { 812 error = copyout(bits, SCARG(uap, fds), ni); 813 if (error) 814 goto out; 815 } 816 out: 817 if (ni > sizeof(smallbits)) 818 free(bits, M_TEMP); 819 return (error); 820 } 821 822 int 823 pollscan(p, fds, nfd, retval) 824 struct proc *p; 825 struct pollfd *fds; 826 int nfd; 827 register_t *retval; 828 { 829 register struct filedesc *fdp = p->p_fd; 830 int i; 831 struct file *fp; 832 int n = 0; 833 834 for (i = 0; i < nfd; i++, fds++) { 835 if ((u_int)fds->fd >= fdp->fd_nfiles) { 836 fds->revents = POLLNVAL; 837 n++; 838 } else { 839 fp = fdp->fd_ofiles[fds->fd]; 840 if (fp == 0) { 841 fds->revents = POLLNVAL; 842 n++; 843 } else { 844 fds->revents = (*fp->f_ops->fo_poll)(fp, 845 fds->events | POLLERR | POLLHUP, p); 846 if (fds->revents != 0) 847 n++; 848 } 849 } 850 } 851 *retval = n; 852 return (0); 853 } 854 855 /*ARGSUSED*/ 856 int 857 seltrue(dev, events, p) 858 dev_t dev; 859 int events; 860 struct proc *p; 861 { 862 863 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 864 } 865 866 /* 867 * Record a select request. 868 */ 869 void 870 selrecord(selector, sip) 871 struct proc *selector; 872 struct selinfo *sip; 873 { 874 struct proc *p; 875 pid_t mypid; 876 877 mypid = selector->p_pid; 878 if (sip->si_pid == mypid) 879 return; 880 if (sip->si_pid && (p = pfind(sip->si_pid)) && 881 p->p_wchan == (caddr_t)&selwait) 882 sip->si_flags |= SI_COLL; 883 else 884 sip->si_pid = mypid; 885 } 886 887 /* 888 * Do a wakeup when a selectable event occurs. 889 */ 890 void 891 selwakeup(sip) 892 register struct selinfo *sip; 893 { 894 register struct proc *p; 895 int s; 896 897 if (sip->si_pid == 0) 898 return; 899 if (sip->si_flags & SI_COLL) { 900 nselcoll++; 901 sip->si_flags &= ~SI_COLL; 902 wakeup((caddr_t)&selwait); 903 } 904 p = pfind(sip->si_pid); 905 sip->si_pid = 0; 906 if (p != NULL) { 907 s = splhigh(); 908 if (p->p_wchan == (caddr_t)&selwait) { 909 if (p->p_stat == SSLEEP) 910 setrunnable(p); 911 else 912 unsleep(p); 913 } else if (p->p_flag & P_SELECT) 914 p->p_flag &= ~P_SELECT; 915 splx(s); 916 } 917 } 918
Indexes created Sun Sep 21 20:09:37 GMT 2025