sys_generic.c revision 1.66
1 /* $NetBSD: sys_generic.c,v 1.66 2002/11/26 18:44:34 christos 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 <sys/cdefs.h> 44 __KERNEL_RCSID(0, "$NetBSD: sys_generic.c,v 1.66 2002/11/26 18:44:34 christos Exp $"); 45 46 #include "opt_ktrace.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/filedesc.h> 51 #include <sys/ioctl.h> 52 #include <sys/file.h> 53 #include <sys/proc.h> 54 #include <sys/socketvar.h> 55 #include <sys/signalvar.h> 56 #include <sys/uio.h> 57 #include <sys/kernel.h> 58 #include <sys/stat.h> 59 #include <sys/malloc.h> 60 #include <sys/poll.h> 61 #ifdef KTRACE 62 #include <sys/ktrace.h> 63 #endif 64 65 #include <sys/mount.h> 66 #include <sys/syscallargs.h> 67 68 int selscan __P((struct proc *, fd_mask *, fd_mask *, int, register_t *)); 69 int pollscan __P((struct proc *, struct pollfd *, int, register_t *)); 70 71 /* 72 * Read system call. 73 */ 74 /* ARGSUSED */ 75 int 76 sys_read(struct proc *p, void *v, 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; 84 struct file *fp; 85 struct filedesc *fdp; 86 87 fd = SCARG(uap, fd); 88 fdp = p->p_fd; 89 90 if ((fp = fd_getfile(fdp, fd)) == NULL) 91 return (EBADF); 92 93 if ((fp->f_flag & FREAD) == 0) 94 return (EBADF); 95 96 FILE_USE(fp); 97 98 /* dofileread() will unuse the descriptor for us */ 99 return (dofileread(p, fd, fp, SCARG(uap, buf), SCARG(uap, nbyte), 100 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 101 } 102 103 int 104 dofileread(struct proc *p, int fd, struct file *fp, void *buf, size_t nbyte, 105 off_t *offset, int flags, register_t *retval) 106 { 107 struct uio auio; 108 struct iovec aiov; 109 size_t cnt; 110 int error; 111 #ifdef KTRACE 112 struct iovec ktriov; 113 #endif 114 error = 0; 115 116 aiov.iov_base = (caddr_t)buf; 117 aiov.iov_len = nbyte; 118 auio.uio_iov = &aiov; 119 auio.uio_iovcnt = 1; 120 auio.uio_resid = nbyte; 121 auio.uio_rw = UIO_READ; 122 auio.uio_segflg = UIO_USERSPACE; 123 auio.uio_procp = p; 124 125 /* 126 * Reads return ssize_t because -1 is returned on error. Therefore 127 * we must restrict the length to SSIZE_MAX to avoid garbage return 128 * values. 129 */ 130 if (auio.uio_resid > SSIZE_MAX) { 131 error = EINVAL; 132 goto out; 133 } 134 135 #ifdef KTRACE 136 /* 137 * if tracing, save a copy of iovec 138 */ 139 if (KTRPOINT(p, KTR_GENIO)) 140 ktriov = aiov; 141 #endif 142 cnt = auio.uio_resid; 143 error = (*fp->f_ops->fo_read)(fp, offset, &auio, fp->f_cred, flags); 144 if (error) 145 if (auio.uio_resid != cnt && (error == ERESTART || 146 error == EINTR || error == EWOULDBLOCK)) 147 error = 0; 148 cnt -= auio.uio_resid; 149 #ifdef KTRACE 150 if (KTRPOINT(p, KTR_GENIO) && error == 0) 151 ktrgenio(p, fd, UIO_READ, &ktriov, cnt, error); 152 #endif 153 *retval = cnt; 154 out: 155 FILE_UNUSE(fp, p); 156 return (error); 157 } 158 159 /* 160 * Scatter read system call. 161 */ 162 int 163 sys_readv(struct proc *p, void *v, register_t *retval) 164 { 165 struct sys_readv_args /* { 166 syscallarg(int) fd; 167 syscallarg(const struct iovec *) iovp; 168 syscallarg(int) iovcnt; 169 } */ *uap = v; 170 int fd; 171 struct file *fp; 172 struct filedesc *fdp; 173 174 fd = SCARG(uap, fd); 175 fdp = p->p_fd; 176 177 if ((fp = fd_getfile(fdp, fd)) == NULL) 178 return (EBADF); 179 180 if ((fp->f_flag & FREAD) == 0) 181 return (EBADF); 182 183 FILE_USE(fp); 184 185 /* dofilereadv() will unuse the descriptor for us */ 186 return (dofilereadv(p, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt), 187 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 188 } 189 190 int 191 dofilereadv(struct proc *p, int fd, struct file *fp, const struct iovec *iovp, 192 int iovcnt, off_t *offset, int flags, register_t *retval) 193 { 194 struct uio auio; 195 struct iovec *iov, *needfree, aiov[UIO_SMALLIOV]; 196 int i, error; 197 size_t cnt; 198 u_int iovlen; 199 #ifdef KTRACE 200 struct iovec *ktriov; 201 #endif 202 203 error = 0; 204 #ifdef KTRACE 205 ktriov = NULL; 206 #endif 207 /* note: can't use iovlen until iovcnt is validated */ 208 iovlen = iovcnt * sizeof(struct iovec); 209 if ((u_int)iovcnt > UIO_SMALLIOV) { 210 if ((u_int)iovcnt > IOV_MAX) { 211 error = EINVAL; 212 goto out; 213 } 214 iov = malloc(iovlen, M_IOV, M_WAITOK); 215 needfree = iov; 216 } else if ((u_int)iovcnt > 0) { 217 iov = aiov; 218 needfree = NULL; 219 } else { 220 error = EINVAL; 221 goto out; 222 } 223 224 auio.uio_iov = iov; 225 auio.uio_iovcnt = iovcnt; 226 auio.uio_rw = UIO_READ; 227 auio.uio_segflg = UIO_USERSPACE; 228 auio.uio_procp = p; 229 error = copyin(iovp, iov, iovlen); 230 if (error) 231 goto done; 232 auio.uio_resid = 0; 233 for (i = 0; i < iovcnt; i++) { 234 auio.uio_resid += iov->iov_len; 235 /* 236 * Reads return ssize_t because -1 is returned on error. 237 * Therefore we must restrict the length to SSIZE_MAX to 238 * avoid garbage return values. 239 */ 240 if (iov->iov_len > SSIZE_MAX || auio.uio_resid > SSIZE_MAX) { 241 error = EINVAL; 242 goto done; 243 } 244 iov++; 245 } 246 #ifdef KTRACE 247 /* 248 * if tracing, save a copy of iovec 249 */ 250 if (KTRPOINT(p, KTR_GENIO)) { 251 ktriov = malloc(iovlen, M_TEMP, M_WAITOK); 252 memcpy((caddr_t)ktriov, (caddr_t)auio.uio_iov, iovlen); 253 } 254 #endif 255 cnt = auio.uio_resid; 256 error = (*fp->f_ops->fo_read)(fp, offset, &auio, fp->f_cred, flags); 257 if (error) 258 if (auio.uio_resid != cnt && (error == ERESTART || 259 error == EINTR || error == EWOULDBLOCK)) 260 error = 0; 261 cnt -= auio.uio_resid; 262 #ifdef KTRACE 263 if (ktriov != NULL) { 264 if (error == 0) 265 ktrgenio(p, fd, UIO_READ, ktriov, cnt, error); 266 free(ktriov, M_TEMP); 267 } 268 #endif 269 *retval = cnt; 270 done: 271 if (needfree) 272 free(needfree, M_IOV); 273 out: 274 FILE_UNUSE(fp, p); 275 return (error); 276 } 277 278 /* 279 * Write system call 280 */ 281 int 282 sys_write(struct proc *p, void *v, register_t *retval) 283 { 284 struct sys_write_args /* { 285 syscallarg(int) fd; 286 syscallarg(const void *) buf; 287 syscallarg(size_t) nbyte; 288 } */ *uap = v; 289 int fd; 290 struct file *fp; 291 struct filedesc *fdp; 292 293 fd = SCARG(uap, fd); 294 fdp = p->p_fd; 295 296 if ((fp = fd_getfile(fdp, fd)) == NULL) 297 return (EBADF); 298 299 if ((fp->f_flag & FWRITE) == 0) 300 return (EBADF); 301 302 FILE_USE(fp); 303 304 /* dofilewrite() will unuse the descriptor for us */ 305 return (dofilewrite(p, fd, fp, SCARG(uap, buf), SCARG(uap, nbyte), 306 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 307 } 308 309 int 310 dofilewrite(struct proc *p, int fd, struct file *fp, const void *buf, 311 size_t nbyte, off_t *offset, int flags, register_t *retval) 312 { 313 struct uio auio; 314 struct iovec aiov; 315 size_t cnt; 316 int error; 317 #ifdef KTRACE 318 struct iovec ktriov; 319 #endif 320 321 error = 0; 322 aiov.iov_base = (caddr_t)buf; /* XXX kills const */ 323 aiov.iov_len = nbyte; 324 auio.uio_iov = &aiov; 325 auio.uio_iovcnt = 1; 326 auio.uio_resid = nbyte; 327 auio.uio_rw = UIO_WRITE; 328 auio.uio_segflg = UIO_USERSPACE; 329 auio.uio_procp = p; 330 331 /* 332 * Writes return ssize_t because -1 is returned on error. Therefore 333 * we must restrict the length to SSIZE_MAX to avoid garbage return 334 * values. 335 */ 336 if (auio.uio_resid > SSIZE_MAX) { 337 error = EINVAL; 338 goto out; 339 } 340 341 #ifdef KTRACE 342 /* 343 * if tracing, save a copy of iovec 344 */ 345 if (KTRPOINT(p, KTR_GENIO)) 346 ktriov = aiov; 347 #endif 348 cnt = auio.uio_resid; 349 error = (*fp->f_ops->fo_write)(fp, offset, &auio, fp->f_cred, flags); 350 if (error) { 351 if (auio.uio_resid != cnt && (error == ERESTART || 352 error == EINTR || error == EWOULDBLOCK)) 353 error = 0; 354 if (error == EPIPE) 355 psignal(p, SIGPIPE); 356 } 357 cnt -= auio.uio_resid; 358 #ifdef KTRACE 359 if (KTRPOINT(p, KTR_GENIO) && error == 0) 360 ktrgenio(p, fd, UIO_WRITE, &ktriov, cnt, error); 361 #endif 362 *retval = cnt; 363 out: 364 FILE_UNUSE(fp, p); 365 return (error); 366 } 367 368 /* 369 * Gather write system call 370 */ 371 int 372 sys_writev(struct proc *p, void *v, register_t *retval) 373 { 374 struct sys_writev_args /* { 375 syscallarg(int) fd; 376 syscallarg(const struct iovec *) iovp; 377 syscallarg(int) iovcnt; 378 } */ *uap = v; 379 int fd; 380 struct file *fp; 381 struct filedesc *fdp; 382 383 fd = SCARG(uap, fd); 384 fdp = p->p_fd; 385 386 if ((fp = fd_getfile(fdp, fd)) == NULL) 387 return (EBADF); 388 389 if ((fp->f_flag & FWRITE) == 0) 390 return (EBADF); 391 392 FILE_USE(fp); 393 394 /* dofilewritev() will unuse the descriptor for us */ 395 return (dofilewritev(p, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt), 396 &fp->f_offset, FOF_UPDATE_OFFSET, retval)); 397 } 398 399 int 400 dofilewritev(struct proc *p, int fd, struct file *fp, const struct iovec *iovp, 401 int iovcnt, off_t *offset, int flags, register_t *retval) 402 { 403 struct uio auio; 404 struct iovec *iov, *needfree, aiov[UIO_SMALLIOV]; 405 int i, error; 406 size_t cnt; 407 u_int iovlen; 408 #ifdef KTRACE 409 struct iovec *ktriov; 410 #endif 411 412 error = 0; 413 #ifdef KTRACE 414 ktriov = NULL; 415 #endif 416 /* note: can't use iovlen until iovcnt is validated */ 417 iovlen = iovcnt * sizeof(struct iovec); 418 if ((u_int)iovcnt > UIO_SMALLIOV) { 419 if ((u_int)iovcnt > IOV_MAX) { 420 error = EINVAL; 421 goto out; 422 } 423 iov = malloc(iovlen, M_IOV, M_WAITOK); 424 needfree = iov; 425 } else if ((u_int)iovcnt > 0) { 426 iov = aiov; 427 needfree = NULL; 428 } else { 429 error = EINVAL; 430 goto out; 431 } 432 433 auio.uio_iov = iov; 434 auio.uio_iovcnt = iovcnt; 435 auio.uio_rw = UIO_WRITE; 436 auio.uio_segflg = UIO_USERSPACE; 437 auio.uio_procp = p; 438 error = copyin(iovp, iov, iovlen); 439 if (error) 440 goto done; 441 auio.uio_resid = 0; 442 for (i = 0; i < iovcnt; i++) { 443 auio.uio_resid += iov->iov_len; 444 /* 445 * Writes return ssize_t because -1 is returned on error. 446 * Therefore we must restrict the length to SSIZE_MAX to 447 * avoid garbage return values. 448 */ 449 if (iov->iov_len > SSIZE_MAX || auio.uio_resid > SSIZE_MAX) { 450 error = EINVAL; 451 goto done; 452 } 453 iov++; 454 } 455 #ifdef KTRACE 456 /* 457 * if tracing, save a copy of iovec 458 */ 459 if (KTRPOINT(p, KTR_GENIO)) { 460 ktriov = malloc(iovlen, M_TEMP, M_WAITOK); 461 memcpy((caddr_t)ktriov, (caddr_t)auio.uio_iov, iovlen); 462 } 463 #endif 464 cnt = auio.uio_resid; 465 error = (*fp->f_ops->fo_write)(fp, offset, &auio, fp->f_cred, flags); 466 if (error) { 467 if (auio.uio_resid != cnt && (error == ERESTART || 468 error == EINTR || error == EWOULDBLOCK)) 469 error = 0; 470 if (error == EPIPE) 471 psignal(p, SIGPIPE); 472 } 473 cnt -= auio.uio_resid; 474 #ifdef KTRACE 475 if (KTRPOINT(p, KTR_GENIO)) 476 if (error == 0) { 477 ktrgenio(p, fd, UIO_WRITE, ktriov, cnt, error); 478 free(ktriov, M_TEMP); 479 } 480 #endif 481 *retval = cnt; 482 done: 483 if (needfree) 484 free(needfree, M_IOV); 485 out: 486 FILE_UNUSE(fp, p); 487 return (error); 488 } 489 490 /* 491 * Ioctl system call 492 */ 493 /* ARGSUSED */ 494 int 495 sys_ioctl(struct proc *p, void *v, register_t *retval) 496 { 497 struct sys_ioctl_args /* { 498 syscallarg(int) fd; 499 syscallarg(u_long) com; 500 syscallarg(caddr_t) data; 501 } */ *uap = v; 502 struct file *fp; 503 struct filedesc *fdp; 504 u_long com; 505 int error; 506 u_int size; 507 caddr_t data, memp; 508 int tmp; 509 #define STK_PARAMS 128 510 u_long stkbuf[STK_PARAMS/sizeof(u_long)]; 511 512 error = 0; 513 fdp = p->p_fd; 514 515 if ((fp = fd_getfile(fdp, SCARG(uap, fd))) == NULL) 516 return (EBADF); 517 518 FILE_USE(fp); 519 520 if ((fp->f_flag & (FREAD | FWRITE)) == 0) { 521 error = EBADF; 522 com = 0; 523 goto out; 524 } 525 526 switch (com = SCARG(uap, com)) { 527 case FIONCLEX: 528 fdp->fd_ofileflags[SCARG(uap, fd)] &= ~UF_EXCLOSE; 529 goto out; 530 531 case FIOCLEX: 532 fdp->fd_ofileflags[SCARG(uap, fd)] |= UF_EXCLOSE; 533 goto out; 534 } 535 536 /* 537 * Interpret high order word to find amount of data to be 538 * copied to/from the user's address space. 539 */ 540 size = IOCPARM_LEN(com); 541 if (size > IOCPARM_MAX) { 542 error = ENOTTY; 543 goto out; 544 } 545 memp = NULL; 546 if (size > sizeof(stkbuf)) { 547 memp = (caddr_t)malloc((u_long)size, M_IOCTLOPS, M_WAITOK); 548 data = memp; 549 } else 550 data = (caddr_t)stkbuf; 551 if (com&IOC_IN) { 552 if (size) { 553 error = copyin(SCARG(uap, data), data, size); 554 if (error) { 555 if (memp) 556 free(memp, M_IOCTLOPS); 557 goto out; 558 } 559 } else 560 *(caddr_t *)data = SCARG(uap, data); 561 } else if ((com&IOC_OUT) && size) 562 /* 563 * Zero the buffer so the user always 564 * gets back something deterministic. 565 */ 566 memset(data, 0, size); 567 else if (com&IOC_VOID) 568 *(caddr_t *)data = SCARG(uap, data); 569 570 switch (com) { 571 572 case FIONBIO: 573 if ((tmp = *(int *)data) != 0) 574 fp->f_flag |= FNONBLOCK; 575 else 576 fp->f_flag &= ~FNONBLOCK; 577 error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); 578 break; 579 580 case FIOASYNC: 581 if ((tmp = *(int *)data) != 0) 582 fp->f_flag |= FASYNC; 583 else 584 fp->f_flag &= ~FASYNC; 585 error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p); 586 break; 587 588 case FIOSETOWN: 589 tmp = *(int *)data; 590 if (fp->f_type == DTYPE_SOCKET) { 591 ((struct socket *)fp->f_data)->so_pgid = tmp; 592 error = 0; 593 break; 594 } 595 if (tmp <= 0) { 596 tmp = -tmp; 597 } else { 598 struct proc *p1 = pfind(tmp); 599 if (p1 == 0) { 600 error = ESRCH; 601 break; 602 } 603 tmp = p1->p_pgrp->pg_id; 604 } 605 error = (*fp->f_ops->fo_ioctl) 606 (fp, TIOCSPGRP, (caddr_t)&tmp, p); 607 break; 608 609 case FIOGETOWN: 610 if (fp->f_type == DTYPE_SOCKET) { 611 error = 0; 612 *(int *)data = ((struct socket *)fp->f_data)->so_pgid; 613 break; 614 } 615 error = (*fp->f_ops->fo_ioctl)(fp, TIOCGPGRP, data, p); 616 if (error == 0) 617 *(int *)data = -*(int *)data; 618 break; 619 620 default: 621 error = (*fp->f_ops->fo_ioctl)(fp, com, data, p); 622 /* 623 * Copy any data to user, size was 624 * already set and checked above. 625 */ 626 if (error == 0 && (com&IOC_OUT) && size) 627 error = copyout(data, SCARG(uap, data), size); 628 break; 629 } 630 if (memp) 631 free(memp, M_IOCTLOPS); 632 out: 633 FILE_UNUSE(fp, p); 634 switch (error) { 635 case -1: 636 printf("sys_ioctl: _IO%s%s('%c', %lu, %lu) returned -1: " 637 "pid=%d comm=%s\n", 638 (com & IOC_IN) ? "W" : "", (com & IOC_OUT) ? "R" : "", 639 (char)IOCGROUP(com), (com & 0xff), IOCPARM_LEN(com), 640 p->p_pid, p->p_comm); 641 /* FALLTHROUGH */ 642 case EPASSTHROUGH: 643 error = ENOTTY; 644 /* FALLTHROUGH */ 645 default: 646 return (error); 647 } 648 } 649 650 int selwait, nselcoll; 651 652 /* 653 * Select system call. 654 */ 655 int 656 sys_select(struct proc *p, void *v, register_t *retval) 657 { 658 struct sys_select_args /* { 659 syscallarg(int) nd; 660 syscallarg(fd_set *) in; 661 syscallarg(fd_set *) ou; 662 syscallarg(fd_set *) ex; 663 syscallarg(struct timeval *) tv; 664 } */ *uap = v; 665 caddr_t bits; 666 char smallbits[howmany(FD_SETSIZE, NFDBITS) * 667 sizeof(fd_mask) * 6]; 668 struct timeval atv; 669 int s, ncoll, error, timo; 670 size_t ni; 671 672 error = 0; 673 if (SCARG(uap, nd) < 0) 674 return (EINVAL); 675 if (SCARG(uap, nd) > p->p_fd->fd_nfiles) { 676 /* forgiving; slightly wrong */ 677 SCARG(uap, nd) = p->p_fd->fd_nfiles; 678 } 679 ni = howmany(SCARG(uap, nd), NFDBITS) * sizeof(fd_mask); 680 if (ni * 6 > sizeof(smallbits)) 681 bits = malloc(ni * 6, M_TEMP, M_WAITOK); 682 else 683 bits = smallbits; 684 685 #define getbits(name, x) \ 686 if (SCARG(uap, name)) { \ 687 error = copyin(SCARG(uap, name), bits + ni * x, ni); \ 688 if (error) \ 689 goto done; \ 690 } else \ 691 memset(bits + ni * x, 0, ni); 692 getbits(in, 0); 693 getbits(ou, 1); 694 getbits(ex, 2); 695 #undef getbits 696 697 timo = 0; 698 if (SCARG(uap, tv)) { 699 error = copyin(SCARG(uap, tv), (caddr_t)&atv, 700 sizeof(atv)); 701 if (error) 702 goto done; 703 if (itimerfix(&atv)) { 704 error = EINVAL; 705 goto done; 706 } 707 s = splclock(); 708 timeradd(&atv, &time, &atv); 709 splx(s); 710 } 711 712 retry: 713 ncoll = nselcoll; 714 p->p_flag |= P_SELECT; 715 error = selscan(p, (fd_mask *)(bits + ni * 0), 716 (fd_mask *)(bits + ni * 3), SCARG(uap, nd), retval); 717 if (error || *retval) 718 goto done; 719 if (SCARG(uap, tv)) { 720 /* 721 * We have to recalculate the timeout on every retry. 722 */ 723 timo = hzto(&atv); 724 if (timo <= 0) 725 goto done; 726 } 727 s = splsched(); 728 if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { 729 splx(s); 730 goto retry; 731 } 732 p->p_flag &= ~P_SELECT; 733 error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo); 734 splx(s); 735 if (error == 0) 736 goto retry; 737 done: 738 p->p_flag &= ~P_SELECT; 739 /* select is not restarted after signals... */ 740 if (error == ERESTART) 741 error = EINTR; 742 if (error == EWOULDBLOCK) 743 error = 0; 744 if (error == 0) { 745 746 #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(struct proc *p, fd_mask *ibitp, fd_mask *obitp, int nfd, 765 register_t *retval) 766 { 767 struct filedesc *fdp; 768 int msk, i, j, fd, n; 769 fd_mask ibits, obits; 770 struct file *fp; 771 static const int flag[3] = { POLLRDNORM | POLLHUP | POLLERR, 772 POLLWRNORM | POLLHUP | POLLERR, 773 POLLRDBAND }; 774 775 fdp = p->p_fd; 776 n = 0; 777 for (msk = 0; msk < 3; msk++) { 778 for (i = 0; i < nfd; i += NFDBITS) { 779 ibits = *ibitp++; 780 obits = 0; 781 while ((j = ffs(ibits)) && (fd = i + --j) < nfd) { 782 ibits &= ~(1 << j); 783 if ((fp = fd_getfile(fdp, fd)) == NULL) 784 return (EBADF); 785 FILE_USE(fp); 786 if ((*fp->f_ops->fo_poll)(fp, flag[msk], p)) { 787 obits |= (1 << j); 788 n++; 789 } 790 FILE_UNUSE(fp, p); 791 } 792 *obitp++ = obits; 793 } 794 } 795 *retval = n; 796 return (0); 797 } 798 799 /* 800 * Poll system call. 801 */ 802 int 803 sys_poll(struct proc *p, void *v, register_t *retval) 804 { 805 struct sys_poll_args /* { 806 syscallarg(struct pollfd *) fds; 807 syscallarg(u_int) nfds; 808 syscallarg(int) timeout; 809 } */ *uap = v; 810 caddr_t bits; 811 char smallbits[32 * sizeof(struct pollfd)]; 812 struct timeval atv; 813 int s, ncoll, error, timo; 814 size_t ni; 815 816 error = 0; 817 if (SCARG(uap, nfds) > p->p_fd->fd_nfiles) { 818 /* forgiving; slightly wrong */ 819 SCARG(uap, nfds) = p->p_fd->fd_nfiles; 820 } 821 ni = SCARG(uap, nfds) * sizeof(struct pollfd); 822 if (ni > sizeof(smallbits)) 823 bits = malloc(ni, M_TEMP, M_WAITOK); 824 else 825 bits = smallbits; 826 827 error = copyin(SCARG(uap, fds), bits, ni); 828 if (error) 829 goto done; 830 831 timo = 0; 832 if (SCARG(uap, timeout) != INFTIM) { 833 atv.tv_sec = SCARG(uap, timeout) / 1000; 834 atv.tv_usec = (SCARG(uap, timeout) % 1000) * 1000; 835 if (itimerfix(&atv)) { 836 error = EINVAL; 837 goto done; 838 } 839 s = splclock(); 840 timeradd(&atv, &time, &atv); 841 splx(s); 842 } 843 844 retry: 845 ncoll = nselcoll; 846 p->p_flag |= P_SELECT; 847 error = pollscan(p, (struct pollfd *)bits, SCARG(uap, nfds), retval); 848 if (error || *retval) 849 goto done; 850 if (SCARG(uap, timeout) != INFTIM) { 851 /* 852 * We have to recalculate the timeout on every retry. 853 */ 854 timo = hzto(&atv); 855 if (timo <= 0) 856 goto done; 857 } 858 s = splsched(); 859 if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { 860 splx(s); 861 goto retry; 862 } 863 p->p_flag &= ~P_SELECT; 864 error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo); 865 splx(s); 866 if (error == 0) 867 goto retry; 868 done: 869 p->p_flag &= ~P_SELECT; 870 /* poll is not restarted after signals... */ 871 if (error == ERESTART) 872 error = EINTR; 873 if (error == EWOULDBLOCK) 874 error = 0; 875 if (error == 0) { 876 error = copyout(bits, SCARG(uap, fds), ni); 877 if (error) 878 goto out; 879 } 880 out: 881 if (ni > sizeof(smallbits)) 882 free(bits, M_TEMP); 883 return (error); 884 } 885 886 int 887 pollscan(struct proc *p, struct pollfd *fds, int nfd, register_t *retval) 888 { 889 struct filedesc *fdp; 890 int i, n; 891 struct file *fp; 892 893 fdp = p->p_fd; 894 n = 0; 895 for (i = 0; i < nfd; i++, fds++) { 896 if (fds->fd >= fdp->fd_nfiles) { 897 fds->revents = POLLNVAL; 898 n++; 899 } else if (fds->fd < 0) { 900 fds->revents = 0; 901 } else { 902 if ((fp = fd_getfile(fdp, fds->fd)) == NULL) { 903 fds->revents = POLLNVAL; 904 n++; 905 } else { 906 FILE_USE(fp); 907 fds->revents = (*fp->f_ops->fo_poll)(fp, 908 fds->events | POLLERR | POLLHUP, p); 909 if (fds->revents != 0) 910 n++; 911 FILE_UNUSE(fp, p); 912 } 913 } 914 } 915 *retval = n; 916 return (0); 917 } 918 919 /*ARGSUSED*/ 920 int 921 seltrue(dev_t dev, int events, struct proc *p) 922 { 923 924 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); 925 } 926 927 /* 928 * Record a select request. 929 */ 930 void 931 selrecord(struct proc *selector, struct selinfo *sip) 932 { 933 struct proc *p; 934 pid_t mypid; 935 936 mypid = selector->p_pid; 937 if (sip->sel_pid == mypid) 938 return; 939 if (sip->sel_pid && (p = pfind(sip->sel_pid)) && 940 p->p_wchan == (caddr_t)&selwait) 941 sip->sel_flags |= SI_COLL; 942 else { 943 sip->sel_flags &= ~SI_COLL; 944 sip->sel_pid = mypid; 945 } 946 } 947 948 /* 949 * Do a wakeup when a selectable event occurs. 950 */ 951 void 952 selwakeup(sip) 953 struct selinfo *sip; 954 { 955 struct proc *p; 956 int s; 957 958 if (sip->sel_pid == 0) 959 return; 960 if (sip->sel_flags & SI_COLL) { 961 nselcoll++; 962 sip->sel_flags &= ~SI_COLL; 963 wakeup((caddr_t)&selwait); 964 } 965 p = pfind(sip->sel_pid); 966 sip->sel_pid = 0; 967 if (p != NULL) { 968 SCHED_LOCK(s); 969 if (p->p_wchan == (caddr_t)&selwait) { 970 if (p->p_stat == SSLEEP) 971 setrunnable(p); 972 else 973 unsleep(p); 974 } else if (p->p_flag & P_SELECT) 975 p->p_flag &= ~P_SELECT; 976 SCHED_UNLOCK(s); 977 } 978 } 979
Indexes created Sun Sep 21 20:09:37 GMT 2025