sys_generic.c revision 1.44
1 /* $NetBSD: sys_generic.c,v 1.44 1998/08/04 04:03:15 perry 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; 122 123 /* 124 * Reads return ssize_t because -1 is returned on error. Therefore 125 * we must restrict the length to SSIZE_MAX to avoid garbage return 126 * values. 127 */ 128 if (auio.uio_resid > SSIZE_MAX) 129 return (EINVAL); 130 131 #ifdef KTRACE 132 /* 133 * if tracing, save a copy of iovec 134 */ 135 if (KTRPOINT(p, KTR_GENIO)) 136 ktriov = aiov; 137 #endif 138 cnt = auio.uio_resid; 139 error = (*fp->f_ops->fo_read)(fp, offset, &auio, fp->f_cred, flags); 140 if (error) 141 if (auio.uio_resid != cnt && (error == ERESTART || 142 error == EINTR || error == EWOULDBLOCK)) 143 error = 0; 144 cnt -= auio.uio_resid; 145 #ifdef KTRACE 146 if (KTRPOINT(p, KTR_GENIO) && error == 0) 147 ktrgenio(p->p_tracep, fd, UIO_READ, &ktriov, cnt, error); 148 #endif 149 *retval = cnt; 150 return (error); 151 } 152 153 /* 154 * Scatter read system call. 155 */ 156 int 157 sys_readv(p, v, retval) 158 struct proc *p; 159 void *v; 160 register_t *retval; 161 { 162 register struct sys_readv_args /* { 163 syscallarg(int) fd; 164 syscallarg(const struct iovec *) iovp; 165 syscallarg(int) iovcnt; 166 } */ *uap = v; 167 int fd = SCARG(uap, fd); 168 register struct file *fp; 169 register struct filedesc *fdp = p->p_fd; 170 171 if ((u_int)fd >= fdp->fd_nfiles || 172 (fp = fdp->fd_ofiles[fd]) == NULL || 173 (fp->f_flag & FREAD) == 0) 174 return (EBADF); 175 176 return (dofilereadv(p, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt), 177 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 178 } 179 180 int 181 dofilereadv(p, fd, fp, iovp, iovcnt, offset, flags, retval) 182 struct proc *p; 183 int fd; 184 struct file *fp; 185 const struct iovec *iovp; 186 int iovcnt; 187 off_t *offset; 188 int flags; 189 register_t *retval; 190 { 191 struct uio auio; 192 register struct iovec *iov; 193 struct iovec *needfree; 194 struct iovec aiov[UIO_SMALLIOV]; 195 long i, cnt, error = 0; 196 u_int iovlen; 197 #ifdef KTRACE 198 struct iovec *ktriov = NULL; 199 #endif 200 201 /* note: can't use iovlen until iovcnt is validated */ 202 iovlen = iovcnt * sizeof(struct iovec); 203 if ((u_int)iovcnt > UIO_SMALLIOV) { 204 if ((u_int)iovcnt > IOV_MAX) 205 return (EINVAL); 206 MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK); 207 needfree = iov; 208 } else if ((u_int)iovcnt > 0) { 209 iov = aiov; 210 needfree = NULL; 211 } else 212 return (EINVAL); 213 214 auio.uio_iov = iov; 215 auio.uio_iovcnt = iovcnt; 216 auio.uio_rw = UIO_READ; 217 auio.uio_segflg = UIO_USERSPACE; 218 auio.uio_procp = p; 219 error = copyin(iovp, iov, iovlen); 220 if (error) 221 goto done; 222 auio.uio_resid = 0; 223 for (i = 0; i < iovcnt; i++) { 224 auio.uio_resid += iov->iov_len; 225 /* 226 * Reads return ssize_t because -1 is returned on error. 227 * Therefore we must restrict the length to SSIZE_MAX to 228 * avoid garbage return values. 229 */ 230 if (iov->iov_len > SSIZE_MAX || auio.uio_resid > SSIZE_MAX) { 231 error = EINVAL; 232 goto done; 233 } 234 iov++; 235 } 236 #ifdef KTRACE 237 /* 238 * if tracing, save a copy of iovec 239 */ 240 if (KTRPOINT(p, KTR_GENIO)) { 241 MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); 242 memcpy((caddr_t)ktriov, (caddr_t)auio.uio_iov, iovlen); 243 } 244 #endif 245 cnt = auio.uio_resid; 246 error = (*fp->f_ops->fo_read)(fp, offset, &auio, fp->f_cred, flags); 247 if (error) 248 if (auio.uio_resid != cnt && (error == ERESTART || 249 error == EINTR || error == EWOULDBLOCK)) 250 error = 0; 251 cnt -= auio.uio_resid; 252 #ifdef KTRACE 253 if (KTRPOINT(p, KTR_GENIO)) 254 if (error == 0) { 255 ktrgenio(p->p_tracep, fd, UIO_READ, ktriov, cnt, 256 error); 257 FREE(ktriov, M_TEMP); 258 } 259 #endif 260 *retval = cnt; 261 done: 262 if (needfree) 263 FREE(needfree, M_IOV); 264 return (error); 265 } 266 267 /* 268 * Write system call 269 */ 270 int 271 sys_write(p, v, retval) 272 struct proc *p; 273 void *v; 274 register_t *retval; 275 { 276 register struct sys_write_args /* { 277 syscallarg(int) fd; 278 syscallarg(const void *) buf; 279 syscallarg(size_t) nbyte; 280 } */ *uap = v; 281 int fd = SCARG(uap, fd); 282 register struct file *fp; 283 register struct filedesc *fdp = p->p_fd; 284 285 if ((u_int)fd >= fdp->fd_nfiles || 286 (fp = fdp->fd_ofiles[fd]) == NULL || 287 (fp->f_flag & FWRITE) == 0) 288 return (EBADF); 289 290 return (dofilewrite(p, fd, fp, SCARG(uap, buf), SCARG(uap, nbyte), 291 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 292 } 293 294 int 295 dofilewrite(p, fd, fp, buf, nbyte, offset, flags, retval) 296 struct proc *p; 297 int fd; 298 struct file *fp; 299 const void *buf; 300 size_t nbyte; 301 off_t *offset; 302 int flags; 303 register_t *retval; 304 { 305 struct uio auio; 306 struct iovec aiov; 307 long cnt, error = 0; 308 #ifdef KTRACE 309 struct iovec ktriov; 310 #endif 311 312 aiov.iov_base = (caddr_t)buf; /* XXX kills const */ 313 aiov.iov_len = nbyte; 314 auio.uio_iov = &aiov; 315 auio.uio_iovcnt = 1; 316 auio.uio_resid = nbyte; 317 auio.uio_rw = UIO_WRITE; 318 auio.uio_segflg = UIO_USERSPACE; 319 auio.uio_procp = p; 320 321 /* 322 * Writes return ssize_t because -1 is returned on error. Therefore 323 * we must restrict the length to SSIZE_MAX to avoid garbage return 324 * values. 325 */ 326 if (auio.uio_resid > SSIZE_MAX) 327 return (EINVAL); 328 329 #ifdef KTRACE 330 /* 331 * if tracing, save a copy of iovec 332 */ 333 if (KTRPOINT(p, KTR_GENIO)) 334 ktriov = aiov; 335 #endif 336 cnt = auio.uio_resid; 337 error = (*fp->f_ops->fo_write)(fp, offset, &auio, fp->f_cred, flags); 338 if (error) { 339 if (auio.uio_resid != cnt && (error == ERESTART || 340 error == EINTR || error == EWOULDBLOCK)) 341 error = 0; 342 if (error == EPIPE) 343 psignal(p, SIGPIPE); 344 } 345 cnt -= auio.uio_resid; 346 #ifdef KTRACE 347 if (KTRPOINT(p, KTR_GENIO) && error == 0) 348 ktrgenio(p->p_tracep, fd, UIO_WRITE, &ktriov, cnt, error); 349 #endif 350 *retval = cnt; 351 return (error); 352 } 353 354 /* 355 * Gather write system call 356 */ 357 int 358 sys_writev(p, v, retval) 359 struct proc *p; 360 void *v; 361 register_t *retval; 362 { 363 register struct sys_writev_args /* { 364 syscallarg(int) fd; 365 syscallarg(const struct iovec *) iovp; 366 syscallarg(int) iovcnt; 367 } */ *uap = v; 368 int fd = SCARG(uap, fd); 369 register struct file *fp; 370 register struct filedesc *fdp = p->p_fd; 371 372 if ((u_int)fd >= fdp->fd_nfiles || 373 (fp = fdp->fd_ofiles[fd]) == NULL || 374 (fp->f_flag & FWRITE) == 0) 375 return (EBADF); 376 377 return (dofilewritev(p, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt), 378 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 379 } 380 381 int 382 dofilewritev(p, fd, fp, iovp, iovcnt, offset, flags, retval) 383 struct proc *p; 384 int fd; 385 struct file *fp; 386 const struct iovec *iovp; 387 int iovcnt; 388 off_t *offset; 389 int flags; 390 register_t *retval; 391 { 392 struct uio auio; 393 register struct iovec *iov; 394 struct iovec *needfree; 395 struct iovec aiov[UIO_SMALLIOV]; 396 long i, cnt, error = 0; 397 u_int iovlen; 398 #ifdef KTRACE 399 struct iovec *ktriov = NULL; 400 #endif 401 402 /* note: can't use iovlen until iovcnt is validated */ 403 iovlen = iovcnt * sizeof(struct iovec); 404 if ((u_int)iovcnt > UIO_SMALLIOV) { 405 if ((u_int)iovcnt > IOV_MAX) 406 return (EINVAL); 407 MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK); 408 needfree = iov; 409 } else if ((u_int)iovcnt > 0) { 410 iov = aiov; 411 needfree = NULL; 412 } else 413 return (EINVAL); 414 415 auio.uio_iov = iov; 416 auio.uio_iovcnt = iovcnt; 417 auio.uio_rw = UIO_WRITE; 418 auio.uio_segflg = UIO_USERSPACE; 419 auio.uio_procp = p; 420 error = copyin(iovp, iov, iovlen); 421 if (error) 422 goto done; 423 auio.uio_resid = 0; 424 for (i = 0; i < iovcnt; i++) { 425 auio.uio_resid += iov->iov_len; 426 /* 427 * Writes return ssize_t because -1 is returned on error. 428 * Therefore we must restrict the length to SSIZE_MAX to 429 * avoid garbage return values. 430 */ 431 if (iov->iov_len > SSIZE_MAX || auio.uio_resid > SSIZE_MAX) { 432 error = EINVAL; 433 goto done; 434 } 435 iov++; 436 } 437 #ifdef KTRACE 438 /* 439 * if tracing, save a copy of iovec 440 */ 441 if (KTRPOINT(p, KTR_GENIO)) { 442 MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); 443 memcpy((caddr_t)ktriov, (caddr_t)auio.uio_iov, iovlen); 444 } 445 #endif 446 cnt = auio.uio_resid; 447 error = (*fp->f_ops->fo_write)(fp, offset, &auio, fp->f_cred, flags); 448 if (error) { 449 if (auio.uio_resid != cnt && (error == ERESTART || 450 error == EINTR || error == EWOULDBLOCK)) 451 error = 0; 452 if (error == EPIPE) 453 psignal(p, SIGPIPE); 454 } 455 cnt -= auio.uio_resid; 456 #ifdef KTRACE 457 if (KTRPOINT(p, KTR_GENIO)) 458 if (error == 0) { 459 ktrgenio(p->p_tracep, fd, UIO_WRITE, ktriov, cnt, 460 error); 461 FREE(ktriov, M_TEMP); 462 } 463 #endif 464 *retval = cnt; 465 done: 466 if (needfree) 467 FREE(needfree, M_IOV); 468 return (error); 469 } 470 471 /* 472 * Ioctl system call 473 */ 474 /* ARGSUSED */ 475 int 476 sys_ioctl(p, v, retval) 477 struct proc *p; 478 void *v; 479 register_t *retval; 480 { 481 register struct sys_ioctl_args /* { 482 syscallarg(int) fd; 483 syscallarg(u_long) com; 484 syscallarg(caddr_t) data; 485 } */ *uap = v; 486 register struct file *fp; 487 register struct filedesc *fdp; 488 register u_long com; 489 register int error; 490 register u_int size; 491 caddr_t data, memp; 492 int tmp; 493 #define STK_PARAMS 128 494 char stkbuf[STK_PARAMS]; 495 496 fdp = p->p_fd; 497 if ((u_int)SCARG(uap, fd) >= fdp->fd_nfiles || 498 (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL) 499 return (EBADF); 500 501 if ((fp->f_flag & (FREAD | FWRITE)) == 0) 502 return (EBADF); 503 504 switch (com = SCARG(uap, com)) { 505 case FIONCLEX: 506 fdp->fd_ofileflags[SCARG(uap, fd)] &= ~UF_EXCLOSE; 507 return (0); 508 case FIOCLEX: 509 fdp->fd_ofileflags[SCARG(uap, fd)] |= UF_EXCLOSE; 510 return (0); 511 } 512 513 /* 514 * Interpret high order word to find amount of data to be 515 * copied to/from the user's address space. 516 */ 517 size = IOCPARM_LEN(com); 518 if (size > IOCPARM_MAX) 519 return (ENOTTY); 520 memp = NULL; 521 if (size > sizeof(stkbuf)) { 522 memp = (caddr_t)malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 523 data = memp; 524 } else 525 data = stkbuf; 526 if (com&IOC_IN) { 527 if (size) { 528 error = copyin(SCARG(uap, data), data, size); 529 if (error) { 530 if (memp) 531 free(memp, M_IOCTLOPS); 532 return (error); 533 } 534 } else 535 *(caddr_t *)data = SCARG(uap, data); 536 } else if ((com&IOC_OUT) && size) 537 /* 538 * Zero the buffer so the user always 539 * gets back something deterministic. 540 */ 541 memset(data, 0, size); 542 else if (com&IOC_VOID) 543 *(caddr_t *)data = SCARG(uap, data); 544 545 switch (com) { 546 547 case FIONBIO: 548 if ((tmp = *(int *)data) != 0) 549 fp->f_flag |= FNONBLOCK; 550 else 551 fp->f_flag &= ~FNONBLOCK; 552 error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 553 break; 554 555 case FIOASYNC: 556 if ((tmp = *(int *)data) != 0) 557 fp->f_flag |= FASYNC; 558 else 559 fp->f_flag &= ~FASYNC; 560 error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p); 561 break; 562 563 case FIOSETOWN: 564 tmp = *(int *)data; 565 if (fp->f_type == DTYPE_SOCKET) { 566 ((struct socket *)fp->f_data)->so_pgid = tmp; 567 error = 0; 568 break; 569 } 570 if (tmp <= 0) { 571 tmp = -tmp; 572 } else { 573 struct proc *p1 = pfind(tmp); 574 if (p1 == 0) { 575 error = ESRCH; 576 break; 577 } 578 tmp = p1->p_pgrp->pg_id; 579 } 580 error = (*fp->f_ops->fo_ioctl) 581 (fp, TIOCSPGRP, (caddr_t)&tmp, p); 582 break; 583 584 case FIOGETOWN: 585 if (fp->f_type == DTYPE_SOCKET) { 586 error = 0; 587 *(int *)data = ((struct socket *)fp->f_data)->so_pgid; 588 break; 589 } 590 error = (*fp->f_ops->fo_ioctl)(fp, TIOCGPGRP, data, p); 591 *(int *)data = -*(int *)data; 592 break; 593 594 default: 595 error = (*fp->f_ops->fo_ioctl)(fp, com, data, p); 596 /* 597 * Copy any data to user, size was 598 * already set and checked above. 599 */ 600 if (error == 0 && (com&IOC_OUT) && size) 601 error = copyout(data, SCARG(uap, data), size); 602 break; 603 } 604 if (memp) 605 free(memp, M_IOCTLOPS); 606 return (error); 607 } 608 609 int selwait, nselcoll; 610 611 /* 612 * Select system call. 613 */ 614 int 615 sys_select(p, v, retval) 616 register struct proc *p; 617 void *v; 618 register_t *retval; 619 { 620 register struct sys_select_args /* { 621 syscallarg(int) nd; 622 syscallarg(fd_set *) in; 623 syscallarg(fd_set *) ou; 624 syscallarg(fd_set *) ex; 625 syscallarg(struct timeval *) tv; 626 } */ *uap = v; 627 caddr_t bits; 628 char smallbits[howmany(FD_SETSIZE, NFDBITS) * sizeof(fd_mask) * 6]; 629 struct timeval atv; 630 int s, ncoll, error = 0, timo; 631 size_t ni; 632 633 if (SCARG(uap, nd) < 0) 634 return (EINVAL); 635 if (SCARG(uap, nd) > p->p_fd->fd_nfiles) { 636 /* forgiving; slightly wrong */ 637 SCARG(uap, nd) = p->p_fd->fd_nfiles; 638 } 639 ni = howmany(SCARG(uap, nd), NFDBITS) * sizeof(fd_mask); 640 if (ni * 6 > sizeof(smallbits)) 641 bits = malloc(ni * 6, M_TEMP, M_WAITOK); 642 else 643 bits = smallbits; 644 645 #define getbits(name, x) \ 646 if (SCARG(uap, name)) { \ 647 error = copyin(SCARG(uap, name), bits + ni * x, ni); \ 648 if (error) \ 649 goto done; \ 650 } else \ 651 memset(bits + ni * x, 0, ni); 652 getbits(in, 0); 653 getbits(ou, 1); 654 getbits(ex, 2); 655 #undef getbits 656 657 if (SCARG(uap, tv)) { 658 error = copyin(SCARG(uap, tv), (caddr_t)&atv, 659 sizeof(atv)); 660 if (error) 661 goto done; 662 if (itimerfix(&atv)) { 663 error = EINVAL; 664 goto done; 665 } 666 s = splclock(); 667 timeradd(&atv, &time, &atv); 668 timo = hzto(&atv); 669 /* 670 * Avoid inadvertently sleeping forever. 671 */ 672 if (timo == 0) 673 timo = 1; 674 splx(s); 675 } else 676 timo = 0; 677 retry: 678 ncoll = nselcoll; 679 p->p_flag |= P_SELECT; 680 error = selscan(p, (fd_mask *)(bits + ni * 0), 681 (fd_mask *)(bits + ni * 3), SCARG(uap, nd), retval); 682 if (error || *retval) 683 goto done; 684 s = splhigh(); 685 if (timo && timercmp(&time, &atv, >=)) { 686 splx(s); 687 goto done; 688 } 689 if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { 690 splx(s); 691 goto retry; 692 } 693 p->p_flag &= ~P_SELECT; 694 error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo); 695 splx(s); 696 if (error == 0) 697 goto retry; 698 done: 699 p->p_flag &= ~P_SELECT; 700 /* select is not restarted after signals... */ 701 if (error == ERESTART) 702 error = EINTR; 703 if (error == EWOULDBLOCK) 704 error = 0; 705 if (error == 0) { 706 #define putbits(name, x) \ 707 if (SCARG(uap, name)) { \ 708 error = copyout(bits + ni * x, SCARG(uap, name), ni); \ 709 if (error) \ 710 goto out; \ 711 } 712 putbits(in, 3); 713 putbits(ou, 4); 714 putbits(ex, 5); 715 #undef putbits 716 } 717 out: 718 if (ni * 6 > sizeof(smallbits)) 719 free(bits, M_TEMP); 720 return (error); 721 } 722 723 int 724 selscan(p, ibitp, obitp, nfd, retval) 725 struct proc *p; 726 fd_mask *ibitp, *obitp; 727 int nfd; 728 register_t *retval; 729 { 730 register struct filedesc *fdp = p->p_fd; 731 register int msk, i, j, fd; 732 register fd_mask ibits, obits; 733 struct file *fp; 734 int n = 0; 735 static int flag[3] = { POLLRDNORM | POLLHUP | POLLERR, 736 POLLWRNORM | POLLHUP | POLLERR, 737 POLLRDBAND }; 738 739 for (msk = 0; msk < 3; msk++) { 740 for (i = 0; i < nfd; i += NFDBITS) { 741 ibits = *ibitp++; 742 obits = 0; 743 while ((j = ffs(ibits)) && (fd = i + --j) < nfd) { 744 ibits &= ~(1 << j); 745 fp = fdp->fd_ofiles[fd]; 746 if (fp == NULL) 747 return (EBADF); 748 if ((*fp->f_ops->fo_poll)(fp, flag[msk], p)) { 749 obits |= (1 << j); 750 n++; 751 } 752 } 753 *obitp++ = obits; 754 } 755 } 756 *retval = n; 757 return (0); 758 } 759 760 /* 761 * Poll system call. 762 */ 763 int 764 sys_poll(p, v, retval) 765 register struct proc *p; 766 void *v; 767 register_t *retval; 768 { 769 register struct sys_poll_args /* { 770 syscallarg(struct pollfd *) fds; 771 syscallarg(u_int) nfds; 772 syscallarg(int) timeout; 773 } */ *uap = v; 774 caddr_t bits; 775 char smallbits[32 * sizeof(struct pollfd)]; 776 struct timeval atv; 777 int s, ncoll, error = 0, timo; 778 size_t ni; 779 780 if (SCARG(uap, nfds) > p->p_fd->fd_nfiles) { 781 /* forgiving; slightly wrong */ 782 SCARG(uap, nfds) = p->p_fd->fd_nfiles; 783 } 784 ni = SCARG(uap, nfds) * sizeof(struct pollfd); 785 if (ni > sizeof(smallbits)) 786 bits = malloc(ni, M_TEMP, M_WAITOK); 787 else 788 bits = smallbits; 789 790 error = copyin(SCARG(uap, fds), bits, ni); 791 if (error) 792 goto done; 793 794 if (SCARG(uap, timeout) != INFTIM) { 795 atv.tv_sec = SCARG(uap, timeout) / 1000; 796 atv.tv_usec = (SCARG(uap, timeout) % 1000) * 1000; 797 if (itimerfix(&atv)) { 798 error = EINVAL; 799 goto done; 800 } 801 s = splclock(); 802 timeradd(&atv, &time, &atv); 803 timo = hzto(&atv); 804 /* 805 * Avoid inadvertently sleeping forever. 806 */ 807 if (timo == 0) 808 timo = 1; 809 splx(s); 810 } else 811 timo = 0; 812 retry: 813 ncoll = nselcoll; 814 p->p_flag |= P_SELECT; 815 error = pollscan(p, (struct pollfd *)bits, SCARG(uap, nfds), retval); 816 if (error || *retval) 817 goto done; 818 s = splhigh(); 819 if (timo && timercmp(&time, &atv, >=)) { 820 splx(s); 821 goto done; 822 } 823 if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { 824 splx(s); 825 goto retry; 826 } 827 p->p_flag &= ~P_SELECT; 828 error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo); 829 splx(s); 830 if (error == 0) 831 goto retry; 832 done: 833 p->p_flag &= ~P_SELECT; 834 /* poll is not restarted after signals... */ 835 if (error == ERESTART) 836 error = EINTR; 837 if (error == EWOULDBLOCK) 838 error = 0; 839 if (error == 0) { 840 error = copyout(bits, SCARG(uap, fds), ni); 841 if (error) 842 goto out; 843 } 844 out: 845 if (ni > sizeof(smallbits)) 846 free(bits, M_TEMP); 847 return (error); 848 } 849 850 int 851 pollscan(p, fds, nfd, retval) 852 struct proc *p; 853 struct pollfd *fds; 854 int nfd; 855 register_t *retval; 856 { 857 register struct filedesc *fdp = p->p_fd; 858 int i; 859 struct file *fp; 860 int n = 0; 861 862 for (i = 0; i < nfd; i++, fds++) { 863 if ((u_int)fds->fd >= fdp->fd_nfiles) { 864 fds->revents = POLLNVAL; 865 n++; 866 } else { 867 fp = fdp->fd_ofiles[fds->fd]; 868 if (fp == 0) { 869 fds->revents = POLLNVAL; 870 n++; 871 } else { 872 fds->revents = (*fp->f_ops->fo_poll)(fp, 873 fds->events | POLLERR | POLLHUP, p); 874 if (fds->revents != 0) 875 n++; 876 } 877 } 878 } 879 *retval = n; 880 return (0); 881 } 882 883 /*ARGSUSED*/ 884 int 885 seltrue(dev, events, p) 886 dev_t dev; 887 int events; 888 struct proc *p; 889 { 890 891 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 892 } 893 894 /* 895 * Record a select request. 896 */ 897 void 898 selrecord(selector, sip) 899 struct proc *selector; 900 struct selinfo *sip; 901 { 902 struct proc *p; 903 pid_t mypid; 904 905 mypid = selector->p_pid; 906 if (sip->si_pid == mypid) 907 return; 908 if (sip->si_pid && (p = pfind(sip->si_pid)) && 909 p->p_wchan == (caddr_t)&selwait) 910 sip->si_flags |= SI_COLL; 911 else 912 sip->si_pid = mypid; 913 } 914 915 /* 916 * Do a wakeup when a selectable event occurs. 917 */ 918 void 919 selwakeup(sip) 920 register struct selinfo *sip; 921 { 922 register struct proc *p; 923 int s; 924 925 if (sip->si_pid == 0) 926 return; 927 if (sip->si_flags & SI_COLL) { 928 nselcoll++; 929 sip->si_flags &= ~SI_COLL; 930 wakeup((caddr_t)&selwait); 931 } 932 p = pfind(sip->si_pid); 933 sip->si_pid = 0; 934 if (p != NULL) { 935 s = splhigh(); 936 if (p->p_wchan == (caddr_t)&selwait) { 937 if (p->p_stat == SSLEEP) 938 setrunnable(p); 939 else 940 unsleep(p); 941 } else if (p->p_flag & P_SELECT) 942 p->p_flag &= ~P_SELECT; 943 splx(s); 944 } 945 } 946
Indexes created Mon Sep 22 10:09:38 GMT 2025