sys_generic.c revision 1.52
1 /* $NetBSD: sys_generic.c,v 1.52 2000/08/21 06:27:59 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 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 struct file *fp; 85 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_iflags & FIF_WANTCLOSE) != 0 || 90 (fp->f_flag & FREAD) == 0) 91 return (EBADF); 92 93 FILE_USE(fp); 94 95 /* dofileread() will unuse the descriptor for us */ 96 return (dofileread(p, fd, fp, SCARG(uap, buf), SCARG(uap, nbyte), 97 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 98 } 99 100 int 101 dofileread(p, fd, fp, buf, nbyte, offset, flags, retval) 102 struct proc *p; 103 int fd; 104 struct file *fp; 105 void *buf; 106 size_t nbyte; 107 off_t *offset; 108 int flags; 109 register_t *retval; 110 { 111 struct uio auio; 112 struct iovec aiov; 113 long cnt, error = 0; 114 #ifdef KTRACE 115 struct iovec ktriov; 116 #endif 117 118 aiov.iov_base = (caddr_t)buf; 119 aiov.iov_len = nbyte; 120 auio.uio_iov = &aiov; 121 auio.uio_iovcnt = 1; 122 auio.uio_resid = nbyte; 123 auio.uio_rw = UIO_READ; 124 auio.uio_segflg = UIO_USERSPACE; 125 auio.uio_procp = p; 126 127 /* 128 * Reads return ssize_t because -1 is returned on error. Therefore 129 * we must restrict the length to SSIZE_MAX to avoid garbage return 130 * values. 131 */ 132 if (auio.uio_resid > SSIZE_MAX) { 133 error = EINVAL; 134 goto out; 135 } 136 137 #ifdef KTRACE 138 /* 139 * if tracing, save a copy of iovec 140 */ 141 if (KTRPOINT(p, KTR_GENIO)) 142 ktriov = aiov; 143 #endif 144 cnt = auio.uio_resid; 145 error = (*fp->f_ops->fo_read)(fp, offset, &auio, fp->f_cred, flags); 146 if (error) 147 if (auio.uio_resid != cnt && (error == ERESTART || 148 error == EINTR || error == EWOULDBLOCK)) 149 error = 0; 150 cnt -= auio.uio_resid; 151 #ifdef KTRACE 152 if (KTRPOINT(p, KTR_GENIO) && error == 0) 153 ktrgenio(p, fd, UIO_READ, &ktriov, cnt, error); 154 #endif 155 *retval = cnt; 156 out: 157 FILE_UNUSE(fp, p); 158 return (error); 159 } 160 161 /* 162 * Scatter read system call. 163 */ 164 int 165 sys_readv(p, v, retval) 166 struct proc *p; 167 void *v; 168 register_t *retval; 169 { 170 struct sys_readv_args /* { 171 syscallarg(int) fd; 172 syscallarg(const struct iovec *) iovp; 173 syscallarg(int) iovcnt; 174 } */ *uap = v; 175 int fd = SCARG(uap, fd); 176 struct file *fp; 177 struct filedesc *fdp = p->p_fd; 178 179 if ((u_int)fd >= fdp->fd_nfiles || 180 (fp = fdp->fd_ofiles[fd]) == NULL || 181 (fp->f_iflags & FIF_WANTCLOSE) != 0 || 182 (fp->f_flag & FREAD) == 0) 183 return (EBADF); 184 185 FILE_USE(fp); 186 187 /* dofilereadv() will unuse the descriptor for us */ 188 return (dofilereadv(p, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt), 189 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 190 } 191 192 int 193 dofilereadv(p, fd, fp, iovp, iovcnt, offset, flags, retval) 194 struct proc *p; 195 int fd; 196 struct file *fp; 197 const struct iovec *iovp; 198 int iovcnt; 199 off_t *offset; 200 int flags; 201 register_t *retval; 202 { 203 struct uio auio; 204 struct iovec *iov; 205 struct iovec *needfree; 206 struct iovec aiov[UIO_SMALLIOV]; 207 long i, cnt, error = 0; 208 u_int iovlen; 209 #ifdef KTRACE 210 struct iovec *ktriov = NULL; 211 #endif 212 213 /* note: can't use iovlen until iovcnt is validated */ 214 iovlen = iovcnt * sizeof(struct iovec); 215 if ((u_int)iovcnt > UIO_SMALLIOV) { 216 if ((u_int)iovcnt > IOV_MAX) { 217 error = EINVAL; 218 goto out; 219 } 220 iov = malloc(iovlen, M_IOV, M_WAITOK); 221 needfree = iov; 222 } else if ((u_int)iovcnt > 0) { 223 iov = aiov; 224 needfree = NULL; 225 } else { 226 error = EINVAL; 227 goto out; 228 } 229 230 auio.uio_iov = iov; 231 auio.uio_iovcnt = iovcnt; 232 auio.uio_rw = UIO_READ; 233 auio.uio_segflg = UIO_USERSPACE; 234 auio.uio_procp = p; 235 error = copyin(iovp, iov, iovlen); 236 if (error) 237 goto done; 238 auio.uio_resid = 0; 239 for (i = 0; i < iovcnt; i++) { 240 auio.uio_resid += iov->iov_len; 241 /* 242 * Reads return ssize_t because -1 is returned on error. 243 * Therefore we must restrict the length to SSIZE_MAX to 244 * avoid garbage return values. 245 */ 246 if (iov->iov_len > SSIZE_MAX || auio.uio_resid > SSIZE_MAX) { 247 error = EINVAL; 248 goto done; 249 } 250 iov++; 251 } 252 #ifdef KTRACE 253 /* 254 * if tracing, save a copy of iovec 255 */ 256 if (KTRPOINT(p, KTR_GENIO)) { 257 ktriov = malloc(iovlen, M_TEMP, M_WAITOK); 258 memcpy((caddr_t)ktriov, (caddr_t)auio.uio_iov, iovlen); 259 } 260 #endif 261 cnt = auio.uio_resid; 262 error = (*fp->f_ops->fo_read)(fp, offset, &auio, fp->f_cred, flags); 263 if (error) 264 if (auio.uio_resid != cnt && (error == ERESTART || 265 error == EINTR || error == EWOULDBLOCK)) 266 error = 0; 267 cnt -= auio.uio_resid; 268 #ifdef KTRACE 269 if (KTRPOINT(p, KTR_GENIO)) 270 if (error == 0) { 271 ktrgenio(p, fd, UIO_READ, ktriov, cnt, error); 272 free(ktriov, M_TEMP); 273 } 274 #endif 275 *retval = cnt; 276 done: 277 if (needfree) 278 free(needfree, M_IOV); 279 out: 280 FILE_UNUSE(fp, p); 281 return (error); 282 } 283 284 /* 285 * Write system call 286 */ 287 int 288 sys_write(p, v, retval) 289 struct proc *p; 290 void *v; 291 register_t *retval; 292 { 293 struct sys_write_args /* { 294 syscallarg(int) fd; 295 syscallarg(const void *) buf; 296 syscallarg(size_t) nbyte; 297 } */ *uap = v; 298 int fd = SCARG(uap, fd); 299 struct file *fp; 300 struct filedesc *fdp = p->p_fd; 301 302 if ((u_int)fd >= fdp->fd_nfiles || 303 (fp = fdp->fd_ofiles[fd]) == NULL || 304 (fp->f_iflags & FIF_WANTCLOSE) != 0 || 305 (fp->f_flag & FWRITE) == 0) 306 return (EBADF); 307 308 FILE_USE(fp); 309 310 /* dofilewrite() will unuse the descriptor for us */ 311 return (dofilewrite(p, fd, fp, SCARG(uap, buf), SCARG(uap, nbyte), 312 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 313 } 314 315 int 316 dofilewrite(p, fd, fp, buf, nbyte, offset, flags, retval) 317 struct proc *p; 318 int fd; 319 struct file *fp; 320 const void *buf; 321 size_t nbyte; 322 off_t *offset; 323 int flags; 324 register_t *retval; 325 { 326 struct uio auio; 327 struct iovec aiov; 328 long cnt, error = 0; 329 #ifdef KTRACE 330 struct iovec ktriov; 331 #endif 332 333 aiov.iov_base = (caddr_t)buf; /* XXX kills const */ 334 aiov.iov_len = nbyte; 335 auio.uio_iov = &aiov; 336 auio.uio_iovcnt = 1; 337 auio.uio_resid = nbyte; 338 auio.uio_rw = UIO_WRITE; 339 auio.uio_segflg = UIO_USERSPACE; 340 auio.uio_procp = p; 341 342 /* 343 * Writes return ssize_t because -1 is returned on error. Therefore 344 * we must restrict the length to SSIZE_MAX to avoid garbage return 345 * values. 346 */ 347 if (auio.uio_resid > SSIZE_MAX) { 348 error = EINVAL; 349 goto out; 350 } 351 352 #ifdef KTRACE 353 /* 354 * if tracing, save a copy of iovec 355 */ 356 if (KTRPOINT(p, KTR_GENIO)) 357 ktriov = aiov; 358 #endif 359 cnt = auio.uio_resid; 360 error = (*fp->f_ops->fo_write)(fp, offset, &auio, fp->f_cred, flags); 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 (KTRPOINT(p, KTR_GENIO) && error == 0) 371 ktrgenio(p, fd, UIO_WRITE, &ktriov, cnt, error); 372 #endif 373 *retval = cnt; 374 out: 375 FILE_UNUSE(fp, p); 376 return (error); 377 } 378 379 /* 380 * Gather write system call 381 */ 382 int 383 sys_writev(p, v, retval) 384 struct proc *p; 385 void *v; 386 register_t *retval; 387 { 388 struct sys_writev_args /* { 389 syscallarg(int) fd; 390 syscallarg(const struct iovec *) iovp; 391 syscallarg(int) iovcnt; 392 } */ *uap = v; 393 int fd = SCARG(uap, fd); 394 struct file *fp; 395 struct filedesc *fdp = p->p_fd; 396 397 if ((u_int)fd >= fdp->fd_nfiles || 398 (fp = fdp->fd_ofiles[fd]) == NULL || 399 (fp->f_iflags & FIF_WANTCLOSE) != 0 || 400 (fp->f_flag & FWRITE) == 0) 401 return (EBADF); 402 403 FILE_USE(fp); 404 405 /* dofilewritev() will unuse the descriptor for us */ 406 return (dofilewritev(p, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt), 407 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 408 } 409 410 int 411 dofilewritev(p, fd, fp, iovp, iovcnt, offset, flags, retval) 412 struct proc *p; 413 int fd; 414 struct file *fp; 415 const struct iovec *iovp; 416 int iovcnt; 417 off_t *offset; 418 int flags; 419 register_t *retval; 420 { 421 struct uio auio; 422 struct iovec *iov; 423 struct iovec *needfree; 424 struct iovec aiov[UIO_SMALLIOV]; 425 long i, cnt, error = 0; 426 u_int iovlen; 427 #ifdef KTRACE 428 struct iovec *ktriov = NULL; 429 #endif 430 431 /* note: can't use iovlen until iovcnt is validated */ 432 iovlen = iovcnt * sizeof(struct iovec); 433 if ((u_int)iovcnt > UIO_SMALLIOV) { 434 if ((u_int)iovcnt > IOV_MAX) 435 return (EINVAL); 436 iov = malloc(iovlen, M_IOV, M_WAITOK); 437 needfree = iov; 438 } else if ((u_int)iovcnt > 0) { 439 iov = aiov; 440 needfree = NULL; 441 } else { 442 error = EINVAL; 443 goto out; 444 } 445 446 auio.uio_iov = iov; 447 auio.uio_iovcnt = iovcnt; 448 auio.uio_rw = UIO_WRITE; 449 auio.uio_segflg = UIO_USERSPACE; 450 auio.uio_procp = p; 451 error = copyin(iovp, iov, iovlen); 452 if (error) 453 goto done; 454 auio.uio_resid = 0; 455 for (i = 0; i < iovcnt; i++) { 456 auio.uio_resid += iov->iov_len; 457 /* 458 * Writes return ssize_t because -1 is returned on error. 459 * Therefore we must restrict the length to SSIZE_MAX to 460 * avoid garbage return values. 461 */ 462 if (iov->iov_len > SSIZE_MAX || auio.uio_resid > SSIZE_MAX) { 463 error = EINVAL; 464 goto done; 465 } 466 iov++; 467 } 468 #ifdef KTRACE 469 /* 470 * if tracing, save a copy of iovec 471 */ 472 if (KTRPOINT(p, KTR_GENIO)) { 473 ktriov = malloc(iovlen, M_TEMP, M_WAITOK); 474 memcpy((caddr_t)ktriov, (caddr_t)auio.uio_iov, iovlen); 475 } 476 #endif 477 cnt = auio.uio_resid; 478 error = (*fp->f_ops->fo_write)(fp, offset, &auio, fp->f_cred, flags); 479 if (error) { 480 if (auio.uio_resid != cnt && (error == ERESTART || 481 error == EINTR || error == EWOULDBLOCK)) 482 error = 0; 483 if (error == EPIPE) 484 psignal(p, SIGPIPE); 485 } 486 cnt -= auio.uio_resid; 487 #ifdef KTRACE 488 if (KTRPOINT(p, KTR_GENIO)) 489 if (error == 0) { 490 ktrgenio(p, fd, UIO_WRITE, ktriov, cnt, error); 491 free(ktriov, M_TEMP); 492 } 493 #endif 494 *retval = cnt; 495 done: 496 if (needfree) 497 free(needfree, M_IOV); 498 out: 499 FILE_UNUSE(fp, p); 500 return (error); 501 } 502 503 /* 504 * Ioctl system call 505 */ 506 /* ARGSUSED */ 507 int 508 sys_ioctl(p, v, retval) 509 struct proc *p; 510 void *v; 511 register_t *retval; 512 { 513 struct sys_ioctl_args /* { 514 syscallarg(int) fd; 515 syscallarg(u_long) com; 516 syscallarg(caddr_t) data; 517 } */ *uap = v; 518 struct file *fp; 519 struct filedesc *fdp; 520 u_long com; 521 int error = 0; 522 u_int size; 523 caddr_t data, memp; 524 int tmp; 525 #define STK_PARAMS 128 526 u_long stkbuf[STK_PARAMS/sizeof(u_long)]; 527 528 fdp = p->p_fd; 529 if ((u_int)SCARG(uap, fd) >= fdp->fd_nfiles || 530 (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL || 531 (fp->f_iflags & FIF_WANTCLOSE) != 0) 532 return (EBADF); 533 534 FILE_USE(fp); 535 536 if ((fp->f_flag & (FREAD | FWRITE)) == 0) { 537 error = EBADF; 538 goto out; 539 } 540 541 switch (com = SCARG(uap, com)) { 542 case FIONCLEX: 543 fdp->fd_ofileflags[SCARG(uap, fd)] &= ~UF_EXCLOSE; 544 goto out; 545 546 case FIOCLEX: 547 fdp->fd_ofileflags[SCARG(uap, fd)] |= UF_EXCLOSE; 548 goto out; 549 } 550 551 /* 552 * Interpret high order word to find amount of data to be 553 * copied to/from the user's address space. 554 */ 555 size = IOCPARM_LEN(com); 556 if (size > IOCPARM_MAX) { 557 error = ENOTTY; 558 goto out; 559 } 560 memp = NULL; 561 if (size > sizeof(stkbuf)) { 562 memp = (caddr_t)malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 563 data = memp; 564 } else 565 data = (caddr_t)stkbuf; 566 if (com&IOC_IN) { 567 if (size) { 568 error = copyin(SCARG(uap, data), data, size); 569 if (error) { 570 if (memp) 571 free(memp, M_IOCTLOPS); 572 goto out; 573 } 574 } else 575 *(caddr_t *)data = SCARG(uap, data); 576 } else if ((com&IOC_OUT) && size) 577 /* 578 * Zero the buffer so the user always 579 * gets back something deterministic. 580 */ 581 memset(data, 0, size); 582 else if (com&IOC_VOID) 583 *(caddr_t *)data = SCARG(uap, data); 584 585 switch (com) { 586 587 case FIONBIO: 588 if ((tmp = *(int *)data) != 0) 589 fp->f_flag |= FNONBLOCK; 590 else 591 fp->f_flag &= ~FNONBLOCK; 592 error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 593 break; 594 595 case FIOASYNC: 596 if ((tmp = *(int *)data) != 0) 597 fp->f_flag |= FASYNC; 598 else 599 fp->f_flag &= ~FASYNC; 600 error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p); 601 break; 602 603 case FIOSETOWN: 604 tmp = *(int *)data; 605 if (fp->f_type == DTYPE_SOCKET) { 606 ((struct socket *)fp->f_data)->so_pgid = tmp; 607 error = 0; 608 break; 609 } 610 if (tmp <= 0) { 611 tmp = -tmp; 612 } else { 613 struct proc *p1 = pfind(tmp); 614 if (p1 == 0) { 615 error = ESRCH; 616 break; 617 } 618 tmp = p1->p_pgrp->pg_id; 619 } 620 error = (*fp->f_ops->fo_ioctl) 621 (fp, TIOCSPGRP, (caddr_t)&tmp, p); 622 break; 623 624 case FIOGETOWN: 625 if (fp->f_type == DTYPE_SOCKET) { 626 error = 0; 627 *(int *)data = ((struct socket *)fp->f_data)->so_pgid; 628 break; 629 } 630 error = (*fp->f_ops->fo_ioctl)(fp, TIOCGPGRP, data, p); 631 *(int *)data = -*(int *)data; 632 break; 633 634 default: 635 error = (*fp->f_ops->fo_ioctl)(fp, com, data, p); 636 /* 637 * Copy any data to user, size was 638 * already set and checked above. 639 */ 640 if (error == 0 && (com&IOC_OUT) && size) 641 error = copyout(data, SCARG(uap, data), size); 642 break; 643 } 644 if (memp) 645 free(memp, M_IOCTLOPS); 646 out: 647 FILE_UNUSE(fp, p); 648 return (error); 649 } 650 651 int selwait, nselcoll; 652 653 /* 654 * Select system call. 655 */ 656 int 657 sys_select(p, v, retval) 658 struct proc *p; 659 void *v; 660 register_t *retval; 661 { 662 struct sys_select_args /* { 663 syscallarg(int) nd; 664 syscallarg(fd_set *) in; 665 syscallarg(fd_set *) ou; 666 syscallarg(fd_set *) ex; 667 syscallarg(struct timeval *) tv; 668 } */ *uap = v; 669 caddr_t bits; 670 char smallbits[howmany(FD_SETSIZE, NFDBITS) * sizeof(fd_mask) * 6]; 671 struct timeval atv; 672 int s, ncoll, error = 0, timo; 673 size_t ni; 674 675 if (SCARG(uap, nd) < 0) 676 return (EINVAL); 677 if (SCARG(uap, nd) > p->p_fd->fd_nfiles) { 678 /* forgiving; slightly wrong */ 679 SCARG(uap, nd) = p->p_fd->fd_nfiles; 680 } 681 ni = howmany(SCARG(uap, nd), NFDBITS) * sizeof(fd_mask); 682 if (ni * 6 > sizeof(smallbits)) 683 bits = malloc(ni * 6, M_TEMP, M_WAITOK); 684 else 685 bits = smallbits; 686 687 #define getbits(name, x) \ 688 if (SCARG(uap, name)) { \ 689 error = copyin(SCARG(uap, name), bits + ni * x, ni); \ 690 if (error) \ 691 goto done; \ 692 } else \ 693 memset(bits + ni * x, 0, ni); 694 getbits(in, 0); 695 getbits(ou, 1); 696 getbits(ex, 2); 697 #undef getbits 698 699 if (SCARG(uap, tv)) { 700 error = copyin(SCARG(uap, tv), (caddr_t)&atv, 701 sizeof(atv)); 702 if (error) 703 goto done; 704 if (itimerfix(&atv)) { 705 error = EINVAL; 706 goto done; 707 } 708 s = splclock(); 709 timeradd(&atv, &time, &atv); 710 splx(s); 711 } else 712 timo = 0; 713 retry: 714 ncoll = nselcoll; 715 p->p_flag |= P_SELECT; 716 error = selscan(p, (fd_mask *)(bits + ni * 0), 717 (fd_mask *)(bits + ni * 3), SCARG(uap, nd), retval); 718 if (error || *retval) 719 goto done; 720 if (SCARG(uap, tv)) { 721 /* 722 * We have to recalculate the timeout on every retry. 723 */ 724 timo = hzto(&atv); 725 if (timo <= 0) 726 goto done; 727 } 728 s = splsched(); 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 /* select is not restarted after signals... */ 741 if (error == ERESTART) 742 error = EINTR; 743 if (error == EWOULDBLOCK) 744 error = 0; 745 if (error == 0) { 746 #define putbits(name, x) \ 747 if (SCARG(uap, name)) { \ 748 error = copyout(bits + ni * x, SCARG(uap, name), ni); \ 749 if (error) \ 750 goto out; \ 751 } 752 putbits(in, 3); 753 putbits(ou, 4); 754 putbits(ex, 5); 755 #undef putbits 756 } 757 out: 758 if (ni * 6 > sizeof(smallbits)) 759 free(bits, M_TEMP); 760 return (error); 761 } 762 763 int 764 selscan(p, ibitp, obitp, nfd, retval) 765 struct proc *p; 766 fd_mask *ibitp, *obitp; 767 int nfd; 768 register_t *retval; 769 { 770 struct filedesc *fdp = p->p_fd; 771 int msk, i, j, fd; 772 fd_mask ibits, obits; 773 struct file *fp; 774 int n = 0; 775 static int flag[3] = { POLLRDNORM | POLLHUP | POLLERR, 776 POLLWRNORM | POLLHUP | POLLERR, 777 POLLRDBAND }; 778 779 for (msk = 0; msk < 3; msk++) { 780 for (i = 0; i < nfd; i += NFDBITS) { 781 ibits = *ibitp++; 782 obits = 0; 783 while ((j = ffs(ibits)) && (fd = i + --j) < nfd) { 784 ibits &= ~(1 << j); 785 fp = fdp->fd_ofiles[fd]; 786 if (fp == NULL || 787 (fp->f_iflags & FIF_WANTCLOSE) != 0) 788 return (EBADF); 789 FILE_USE(fp); 790 if ((*fp->f_ops->fo_poll)(fp, flag[msk], p)) { 791 obits |= (1 << j); 792 n++; 793 } 794 FILE_UNUSE(fp, p); 795 } 796 *obitp++ = obits; 797 } 798 } 799 *retval = n; 800 return (0); 801 } 802 803 /* 804 * Poll system call. 805 */ 806 int 807 sys_poll(p, v, retval) 808 struct proc *p; 809 void *v; 810 register_t *retval; 811 { 812 struct sys_poll_args /* { 813 syscallarg(struct pollfd *) fds; 814 syscallarg(u_int) nfds; 815 syscallarg(int) timeout; 816 } */ *uap = v; 817 caddr_t bits; 818 char smallbits[32 * sizeof(struct pollfd)]; 819 struct timeval atv; 820 int s, ncoll, error = 0, timo; 821 size_t ni; 822 823 if (SCARG(uap, nfds) > p->p_fd->fd_nfiles) { 824 /* forgiving; slightly wrong */ 825 SCARG(uap, nfds) = p->p_fd->fd_nfiles; 826 } 827 ni = SCARG(uap, nfds) * sizeof(struct pollfd); 828 if (ni > sizeof(smallbits)) 829 bits = malloc(ni, M_TEMP, M_WAITOK); 830 else 831 bits = smallbits; 832 833 error = copyin(SCARG(uap, fds), bits, ni); 834 if (error) 835 goto done; 836 837 if (SCARG(uap, timeout) != INFTIM) { 838 atv.tv_sec = SCARG(uap, timeout) / 1000; 839 atv.tv_usec = (SCARG(uap, timeout) % 1000) * 1000; 840 if (itimerfix(&atv)) { 841 error = EINVAL; 842 goto done; 843 } 844 s = splclock(); 845 timeradd(&atv, &time, &atv); 846 splx(s); 847 } else 848 timo = 0; 849 retry: 850 ncoll = nselcoll; 851 p->p_flag |= P_SELECT; 852 error = pollscan(p, (struct pollfd *)bits, SCARG(uap, nfds), retval); 853 if (error || *retval) 854 goto done; 855 if (SCARG(uap, timeout) != INFTIM) { 856 /* 857 * We have to recalculate the timeout on every retry. 858 */ 859 timo = hzto(&atv); 860 if (timo <= 0) 861 goto done; 862 } 863 s = splsched(); 864 if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { 865 splx(s); 866 goto retry; 867 } 868 p->p_flag &= ~P_SELECT; 869 error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo); 870 splx(s); 871 if (error == 0) 872 goto retry; 873 done: 874 p->p_flag &= ~P_SELECT; 875 /* poll is not restarted after signals... */ 876 if (error == ERESTART) 877 error = EINTR; 878 if (error == EWOULDBLOCK) 879 error = 0; 880 if (error == 0) { 881 error = copyout(bits, SCARG(uap, fds), ni); 882 if (error) 883 goto out; 884 } 885 out: 886 if (ni > sizeof(smallbits)) 887 free(bits, M_TEMP); 888 return (error); 889 } 890 891 int 892 pollscan(p, fds, nfd, retval) 893 struct proc *p; 894 struct pollfd *fds; 895 int nfd; 896 register_t *retval; 897 { 898 struct filedesc *fdp = p->p_fd; 899 int i; 900 struct file *fp; 901 int n = 0; 902 903 for (i = 0; i < nfd; i++, fds++) { 904 if ((u_int)fds->fd >= fdp->fd_nfiles) { 905 fds->revents = POLLNVAL; 906 n++; 907 } else { 908 fp = fdp->fd_ofiles[fds->fd]; 909 if (fp == NULL || 910 (fp->f_iflags & FIF_WANTCLOSE) != 0) { 911 fds->revents = POLLNVAL; 912 n++; 913 } else { 914 FILE_USE(fp); 915 fds->revents = (*fp->f_ops->fo_poll)(fp, 916 fds->events | POLLERR | POLLHUP, p); 917 if (fds->revents != 0) 918 n++; 919 FILE_UNUSE(fp, p); 920 } 921 } 922 } 923 *retval = n; 924 return (0); 925 } 926 927 /*ARGSUSED*/ 928 int 929 seltrue(dev, events, p) 930 dev_t dev; 931 int events; 932 struct proc *p; 933 { 934 935 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 936 } 937 938 /* 939 * Record a select request. 940 */ 941 void 942 selrecord(selector, sip) 943 struct proc *selector; 944 struct selinfo *sip; 945 { 946 struct proc *p; 947 pid_t mypid; 948 949 mypid = selector->p_pid; 950 if (sip->si_pid == mypid) 951 return; 952 if (sip->si_pid && (p = pfind(sip->si_pid)) && 953 p->p_wchan == (caddr_t)&selwait) 954 sip->si_flags |= SI_COLL; 955 else 956 sip->si_pid = mypid; 957 } 958 959 /* 960 * Do a wakeup when a selectable event occurs. 961 */ 962 void 963 selwakeup(sip) 964 struct selinfo *sip; 965 { 966 struct proc *p; 967 int s; 968 969 if (sip->si_pid == 0) 970 return; 971 if (sip->si_flags & SI_COLL) { 972 nselcoll++; 973 sip->si_flags &= ~SI_COLL; 974 wakeup((caddr_t)&selwait); 975 } 976 p = pfind(sip->si_pid); 977 sip->si_pid = 0; 978 if (p != NULL) { 979 SCHED_LOCK(s); 980 if (p->p_wchan == (caddr_t)&selwait) { 981 if (p->p_stat == SSLEEP) 982 setrunnable(p); 983 else 984 unsleep(p); 985 } else if (p->p_flag & P_SELECT) 986 p->p_flag &= ~P_SELECT; 987 SCHED_UNLOCK(s); 988 } 989 } 990
Indexes created Mon Sep 22 10:09:38 GMT 2025