The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/kern/sys_generic.c

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    1 /*-
    2  * Copyright (c) 1982, 1986, 1989, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  * (c) UNIX System Laboratories, Inc.
    5  * All or some portions of this file are derived from material licensed
    6  * to the University of California by American Telephone and Telegraph
    7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
    8  * the permission of UNIX System Laboratories, Inc.
    9  *
   10  * Redistribution and use in source and binary forms, with or without
   11  * modification, are permitted provided that the following conditions
   12  * are met:
   13  * 1. Redistributions of source code must retain the above copyright
   14  *    notice, this list of conditions and the following disclaimer.
   15  * 2. Redistributions in binary form must reproduce the above copyright
   16  *    notice, this list of conditions and the following disclaimer in the
   17  *    documentation and/or other materials provided with the distribution.
   18  * 4. Neither the name of the University nor the names of its contributors
   19  *    may be used to endorse or promote products derived from this software
   20  *    without specific prior written permission.
   21  *
   22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   32  * SUCH DAMAGE.
   33  *
   34  *      @(#)sys_generic.c       8.5 (Berkeley) 1/21/94
   35  */
   36 
   37 #include <sys/cdefs.h>
   38 __FBSDID("$FreeBSD: releng/9.0/sys/kern/sys_generic.c 228034 2011-11-27 19:00:52Z kib $");
   39 
   40 #include "opt_capsicum.h"
   41 #include "opt_compat.h"
   42 #include "opt_ktrace.h"
   43 
   44 #include <sys/param.h>
   45 #include <sys/systm.h>
   46 #include <sys/sysproto.h>
   47 #include <sys/capability.h>
   48 #include <sys/filedesc.h>
   49 #include <sys/filio.h>
   50 #include <sys/fcntl.h>
   51 #include <sys/file.h>
   52 #include <sys/proc.h>
   53 #include <sys/signalvar.h>
   54 #include <sys/socketvar.h>
   55 #include <sys/uio.h>
   56 #include <sys/kernel.h>
   57 #include <sys/ktr.h>
   58 #include <sys/limits.h>
   59 #include <sys/malloc.h>
   60 #include <sys/poll.h>
   61 #include <sys/resourcevar.h>
   62 #include <sys/selinfo.h>
   63 #include <sys/sleepqueue.h>
   64 #include <sys/syscallsubr.h>
   65 #include <sys/sysctl.h>
   66 #include <sys/sysent.h>
   67 #include <sys/vnode.h>
   68 #include <sys/bio.h>
   69 #include <sys/buf.h>
   70 #include <sys/condvar.h>
   71 #ifdef KTRACE
   72 #include <sys/ktrace.h>
   73 #endif
   74 
   75 #include <security/audit/audit.h>
   76 
   77 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer");
   78 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer");
   79 MALLOC_DEFINE(M_IOV, "iov", "large iov's");
   80 
   81 static int      pollout(struct thread *, struct pollfd *, struct pollfd *,
   82                     u_int);
   83 static int      pollscan(struct thread *, struct pollfd *, u_int);
   84 static int      pollrescan(struct thread *);
   85 static int      selscan(struct thread *, fd_mask **, fd_mask **, int);
   86 static int      selrescan(struct thread *, fd_mask **, fd_mask **);
   87 static void     selfdalloc(struct thread *, void *);
   88 static void     selfdfree(struct seltd *, struct selfd *);
   89 static int      dofileread(struct thread *, int, struct file *, struct uio *,
   90                     off_t, int);
   91 static int      dofilewrite(struct thread *, int, struct file *, struct uio *,
   92                     off_t, int);
   93 static void     doselwakeup(struct selinfo *, int);
   94 static void     seltdinit(struct thread *);
   95 static int      seltdwait(struct thread *, int);
   96 static void     seltdclear(struct thread *);
   97 
   98 /*
   99  * One seltd per-thread allocated on demand as needed.
  100  *
  101  *      t - protected by st_mtx
  102  *      k - Only accessed by curthread or read-only
  103  */
  104 struct seltd {
  105         STAILQ_HEAD(, selfd)    st_selq;        /* (k) List of selfds. */
  106         struct selfd            *st_free1;      /* (k) free fd for read set. */
  107         struct selfd            *st_free2;      /* (k) free fd for write set. */
  108         struct mtx              st_mtx;         /* Protects struct seltd */
  109         struct cv               st_wait;        /* (t) Wait channel. */
  110         int                     st_flags;       /* (t) SELTD_ flags. */
  111 };
  112 
  113 #define SELTD_PENDING   0x0001                  /* We have pending events. */
  114 #define SELTD_RESCAN    0x0002                  /* Doing a rescan. */
  115 
  116 /*
  117  * One selfd allocated per-thread per-file-descriptor.
  118  *      f - protected by sf_mtx
  119  */
  120 struct selfd {
  121         STAILQ_ENTRY(selfd)     sf_link;        /* (k) fds owned by this td. */
  122         TAILQ_ENTRY(selfd)      sf_threads;     /* (f) fds on this selinfo. */
  123         struct selinfo          *sf_si;         /* (f) selinfo when linked. */
  124         struct mtx              *sf_mtx;        /* Pointer to selinfo mtx. */
  125         struct seltd            *sf_td;         /* (k) owning seltd. */
  126         void                    *sf_cookie;     /* (k) fd or pollfd. */
  127 };
  128 
  129 static uma_zone_t selfd_zone;
  130 static struct mtx_pool *mtxpool_select;
  131 
  132 #ifndef _SYS_SYSPROTO_H_
  133 struct read_args {
  134         int     fd;
  135         void    *buf;
  136         size_t  nbyte;
  137 };
  138 #endif
  139 int
  140 sys_read(td, uap)
  141         struct thread *td;
  142         struct read_args *uap;
  143 {
  144         struct uio auio;
  145         struct iovec aiov;
  146         int error;
  147 
  148         if (uap->nbyte > INT_MAX)
  149                 return (EINVAL);
  150         aiov.iov_base = uap->buf;
  151         aiov.iov_len = uap->nbyte;
  152         auio.uio_iov = &aiov;
  153         auio.uio_iovcnt = 1;
  154         auio.uio_resid = uap->nbyte;
  155         auio.uio_segflg = UIO_USERSPACE;
  156         error = kern_readv(td, uap->fd, &auio);
  157         return(error);
  158 }
  159 
  160 /*
  161  * Positioned read system call
  162  */
  163 #ifndef _SYS_SYSPROTO_H_
  164 struct pread_args {
  165         int     fd;
  166         void    *buf;
  167         size_t  nbyte;
  168         int     pad;
  169         off_t   offset;
  170 };
  171 #endif
  172 int
  173 sys_pread(td, uap)
  174         struct thread *td;
  175         struct pread_args *uap;
  176 {
  177         struct uio auio;
  178         struct iovec aiov;
  179         int error;
  180 
  181         if (uap->nbyte > INT_MAX)
  182                 return (EINVAL);
  183         aiov.iov_base = uap->buf;
  184         aiov.iov_len = uap->nbyte;
  185         auio.uio_iov = &aiov;
  186         auio.uio_iovcnt = 1;
  187         auio.uio_resid = uap->nbyte;
  188         auio.uio_segflg = UIO_USERSPACE;
  189         error = kern_preadv(td, uap->fd, &auio, uap->offset);
  190         return(error);
  191 }
  192 
  193 int
  194 freebsd6_pread(td, uap)
  195         struct thread *td;
  196         struct freebsd6_pread_args *uap;
  197 {
  198         struct pread_args oargs;
  199 
  200         oargs.fd = uap->fd;
  201         oargs.buf = uap->buf;
  202         oargs.nbyte = uap->nbyte;
  203         oargs.offset = uap->offset;
  204         return (sys_pread(td, &oargs));
  205 }
  206 
  207 /*
  208  * Scatter read system call.
  209  */
  210 #ifndef _SYS_SYSPROTO_H_
  211 struct readv_args {
  212         int     fd;
  213         struct  iovec *iovp;
  214         u_int   iovcnt;
  215 };
  216 #endif
  217 int
  218 sys_readv(struct thread *td, struct readv_args *uap)
  219 {
  220         struct uio *auio;
  221         int error;
  222 
  223         error = copyinuio(uap->iovp, uap->iovcnt, &auio);
  224         if (error)
  225                 return (error);
  226         error = kern_readv(td, uap->fd, auio);
  227         free(auio, M_IOV);
  228         return (error);
  229 }
  230 
  231 int
  232 kern_readv(struct thread *td, int fd, struct uio *auio)
  233 {
  234         struct file *fp;
  235         int error;
  236 
  237         error = fget_read(td, fd, CAP_READ | CAP_SEEK, &fp);
  238         if (error)
  239                 return (error);
  240         error = dofileread(td, fd, fp, auio, (off_t)-1, 0);
  241         fdrop(fp, td);
  242         return (error);
  243 }
  244 
  245 /*
  246  * Scatter positioned read system call.
  247  */
  248 #ifndef _SYS_SYSPROTO_H_
  249 struct preadv_args {
  250         int     fd;
  251         struct  iovec *iovp;
  252         u_int   iovcnt;
  253         off_t   offset;
  254 };
  255 #endif
  256 int
  257 sys_preadv(struct thread *td, struct preadv_args *uap)
  258 {
  259         struct uio *auio;
  260         int error;
  261 
  262         error = copyinuio(uap->iovp, uap->iovcnt, &auio);
  263         if (error)
  264                 return (error);
  265         error = kern_preadv(td, uap->fd, auio, uap->offset);
  266         free(auio, M_IOV);
  267         return (error);
  268 }
  269 
  270 int
  271 kern_preadv(td, fd, auio, offset)
  272         struct thread *td;
  273         int fd;
  274         struct uio *auio;
  275         off_t offset;
  276 {
  277         struct file *fp;
  278         int error;
  279 
  280         error = fget_read(td, fd, CAP_READ, &fp);
  281         if (error)
  282                 return (error);
  283         if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
  284                 error = ESPIPE;
  285         else if (offset < 0 && fp->f_vnode->v_type != VCHR)
  286                 error = EINVAL;
  287         else
  288                 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET);
  289         fdrop(fp, td);
  290         return (error);
  291 }
  292 
  293 /*
  294  * Common code for readv and preadv that reads data in
  295  * from a file using the passed in uio, offset, and flags.
  296  */
  297 static int
  298 dofileread(td, fd, fp, auio, offset, flags)
  299         struct thread *td;
  300         int fd;
  301         struct file *fp;
  302         struct uio *auio;
  303         off_t offset;
  304         int flags;
  305 {
  306         ssize_t cnt;
  307         int error;
  308 #ifdef KTRACE
  309         struct uio *ktruio = NULL;
  310 #endif
  311 
  312         /* Finish zero length reads right here */
  313         if (auio->uio_resid == 0) {
  314                 td->td_retval[0] = 0;
  315                 return(0);
  316         }
  317         auio->uio_rw = UIO_READ;
  318         auio->uio_offset = offset;
  319         auio->uio_td = td;
  320 #ifdef KTRACE
  321         if (KTRPOINT(td, KTR_GENIO)) 
  322                 ktruio = cloneuio(auio);
  323 #endif
  324         cnt = auio->uio_resid;
  325         if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) {
  326                 if (auio->uio_resid != cnt && (error == ERESTART ||
  327                     error == EINTR || error == EWOULDBLOCK))
  328                         error = 0;
  329         }
  330         cnt -= auio->uio_resid;
  331 #ifdef KTRACE
  332         if (ktruio != NULL) {
  333                 ktruio->uio_resid = cnt;
  334                 ktrgenio(fd, UIO_READ, ktruio, error);
  335         }
  336 #endif
  337         td->td_retval[0] = cnt;
  338         return (error);
  339 }
  340 
  341 #ifndef _SYS_SYSPROTO_H_
  342 struct write_args {
  343         int     fd;
  344         const void *buf;
  345         size_t  nbyte;
  346 };
  347 #endif
  348 int
  349 sys_write(td, uap)
  350         struct thread *td;
  351         struct write_args *uap;
  352 {
  353         struct uio auio;
  354         struct iovec aiov;
  355         int error;
  356 
  357         if (uap->nbyte > INT_MAX)
  358                 return (EINVAL);
  359         aiov.iov_base = (void *)(uintptr_t)uap->buf;
  360         aiov.iov_len = uap->nbyte;
  361         auio.uio_iov = &aiov;
  362         auio.uio_iovcnt = 1;
  363         auio.uio_resid = uap->nbyte;
  364         auio.uio_segflg = UIO_USERSPACE;
  365         error = kern_writev(td, uap->fd, &auio);
  366         return(error);
  367 }
  368 
  369 /*
  370  * Positioned write system call.
  371  */
  372 #ifndef _SYS_SYSPROTO_H_
  373 struct pwrite_args {
  374         int     fd;
  375         const void *buf;
  376         size_t  nbyte;
  377         int     pad;
  378         off_t   offset;
  379 };
  380 #endif
  381 int
  382 sys_pwrite(td, uap)
  383         struct thread *td;
  384         struct pwrite_args *uap;
  385 {
  386         struct uio auio;
  387         struct iovec aiov;
  388         int error;
  389 
  390         if (uap->nbyte > INT_MAX)
  391                 return (EINVAL);
  392         aiov.iov_base = (void *)(uintptr_t)uap->buf;
  393         aiov.iov_len = uap->nbyte;
  394         auio.uio_iov = &aiov;
  395         auio.uio_iovcnt = 1;
  396         auio.uio_resid = uap->nbyte;
  397         auio.uio_segflg = UIO_USERSPACE;
  398         error = kern_pwritev(td, uap->fd, &auio, uap->offset);
  399         return(error);
  400 }
  401 
  402 int
  403 freebsd6_pwrite(td, uap)
  404         struct thread *td;
  405         struct freebsd6_pwrite_args *uap;
  406 {
  407         struct pwrite_args oargs;
  408 
  409         oargs.fd = uap->fd;
  410         oargs.buf = uap->buf;
  411         oargs.nbyte = uap->nbyte;
  412         oargs.offset = uap->offset;
  413         return (sys_pwrite(td, &oargs));
  414 }
  415 
  416 /*
  417  * Gather write system call.
  418  */
  419 #ifndef _SYS_SYSPROTO_H_
  420 struct writev_args {
  421         int     fd;
  422         struct  iovec *iovp;
  423         u_int   iovcnt;
  424 };
  425 #endif
  426 int
  427 sys_writev(struct thread *td, struct writev_args *uap)
  428 {
  429         struct uio *auio;
  430         int error;
  431 
  432         error = copyinuio(uap->iovp, uap->iovcnt, &auio);
  433         if (error)
  434                 return (error);
  435         error = kern_writev(td, uap->fd, auio);
  436         free(auio, M_IOV);
  437         return (error);
  438 }
  439 
  440 int
  441 kern_writev(struct thread *td, int fd, struct uio *auio)
  442 {
  443         struct file *fp;
  444         int error;
  445 
  446         error = fget_write(td, fd, CAP_WRITE | CAP_SEEK, &fp);
  447         if (error)
  448                 return (error);
  449         error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0);
  450         fdrop(fp, td);
  451         return (error);
  452 }
  453 
  454 /*
  455  * Gather positioned write system call.
  456  */
  457 #ifndef _SYS_SYSPROTO_H_
  458 struct pwritev_args {
  459         int     fd;
  460         struct  iovec *iovp;
  461         u_int   iovcnt;
  462         off_t   offset;
  463 };
  464 #endif
  465 int
  466 sys_pwritev(struct thread *td, struct pwritev_args *uap)
  467 {
  468         struct uio *auio;
  469         int error;
  470 
  471         error = copyinuio(uap->iovp, uap->iovcnt, &auio);
  472         if (error)
  473                 return (error);
  474         error = kern_pwritev(td, uap->fd, auio, uap->offset);
  475         free(auio, M_IOV);
  476         return (error);
  477 }
  478 
  479 int
  480 kern_pwritev(td, fd, auio, offset)
  481         struct thread *td;
  482         struct uio *auio;
  483         int fd;
  484         off_t offset;
  485 {
  486         struct file *fp;
  487         int error;
  488 
  489         error = fget_write(td, fd, CAP_WRITE, &fp);
  490         if (error)
  491                 return (error);
  492         if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
  493                 error = ESPIPE;
  494         else if (offset < 0 && fp->f_vnode->v_type != VCHR)
  495                 error = EINVAL;
  496         else
  497                 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET);
  498         fdrop(fp, td);
  499         return (error);
  500 }
  501 
  502 /*
  503  * Common code for writev and pwritev that writes data to
  504  * a file using the passed in uio, offset, and flags.
  505  */
  506 static int
  507 dofilewrite(td, fd, fp, auio, offset, flags)
  508         struct thread *td;
  509         int fd;
  510         struct file *fp;
  511         struct uio *auio;
  512         off_t offset;
  513         int flags;
  514 {
  515         ssize_t cnt;
  516         int error;
  517 #ifdef KTRACE
  518         struct uio *ktruio = NULL;
  519 #endif
  520 
  521         auio->uio_rw = UIO_WRITE;
  522         auio->uio_td = td;
  523         auio->uio_offset = offset;
  524 #ifdef KTRACE
  525         if (KTRPOINT(td, KTR_GENIO))
  526                 ktruio = cloneuio(auio);
  527 #endif
  528         cnt = auio->uio_resid;
  529         if (fp->f_type == DTYPE_VNODE)
  530                 bwillwrite();
  531         if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) {
  532                 if (auio->uio_resid != cnt && (error == ERESTART ||
  533                     error == EINTR || error == EWOULDBLOCK))
  534                         error = 0;
  535                 /* Socket layer is responsible for issuing SIGPIPE. */
  536                 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) {
  537                         PROC_LOCK(td->td_proc);
  538                         tdsignal(td, SIGPIPE);
  539                         PROC_UNLOCK(td->td_proc);
  540                 }
  541         }
  542         cnt -= auio->uio_resid;
  543 #ifdef KTRACE
  544         if (ktruio != NULL) {
  545                 ktruio->uio_resid = cnt;
  546                 ktrgenio(fd, UIO_WRITE, ktruio, error);
  547         }
  548 #endif
  549         td->td_retval[0] = cnt;
  550         return (error);
  551 }
  552 
  553 /*
  554  * Truncate a file given a file descriptor.
  555  *
  556  * Can't use fget_write() here, since must return EINVAL and not EBADF if the
  557  * descriptor isn't writable.
  558  */
  559 int
  560 kern_ftruncate(td, fd, length)
  561         struct thread *td;
  562         int fd;
  563         off_t length;
  564 {
  565         struct file *fp;
  566         int error;
  567 
  568         AUDIT_ARG_FD(fd);
  569         if (length < 0)
  570                 return (EINVAL);
  571         error = fget(td, fd, CAP_FTRUNCATE, &fp);
  572         if (error)
  573                 return (error);
  574         AUDIT_ARG_FILE(td->td_proc, fp);
  575         if (!(fp->f_flag & FWRITE)) {
  576                 fdrop(fp, td);
  577                 return (EINVAL);
  578         }
  579         error = fo_truncate(fp, length, td->td_ucred, td);
  580         fdrop(fp, td);
  581         return (error);
  582 }
  583 
  584 #ifndef _SYS_SYSPROTO_H_
  585 struct ftruncate_args {
  586         int     fd;
  587         int     pad;
  588         off_t   length;
  589 };
  590 #endif
  591 int
  592 sys_ftruncate(td, uap)
  593         struct thread *td;
  594         struct ftruncate_args *uap;
  595 {
  596 
  597         return (kern_ftruncate(td, uap->fd, uap->length));
  598 }
  599 
  600 #if defined(COMPAT_43)
  601 #ifndef _SYS_SYSPROTO_H_
  602 struct oftruncate_args {
  603         int     fd;
  604         long    length;
  605 };
  606 #endif
  607 int
  608 oftruncate(td, uap)
  609         struct thread *td;
  610         struct oftruncate_args *uap;
  611 {
  612 
  613         return (kern_ftruncate(td, uap->fd, uap->length));
  614 }
  615 #endif /* COMPAT_43 */
  616 
  617 #ifndef _SYS_SYSPROTO_H_
  618 struct ioctl_args {
  619         int     fd;
  620         u_long  com;
  621         caddr_t data;
  622 };
  623 #endif
  624 /* ARGSUSED */
  625 int
  626 sys_ioctl(struct thread *td, struct ioctl_args *uap)
  627 {
  628         u_long com;
  629         int arg, error;
  630         u_int size;
  631         caddr_t data;
  632 
  633         if (uap->com > 0xffffffff) {
  634                 printf(
  635                     "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n",
  636                     td->td_proc->p_pid, td->td_name, uap->com);
  637                 uap->com &= 0xffffffff;
  638         }
  639         com = uap->com;
  640 
  641         /*
  642          * Interpret high order word to find amount of data to be
  643          * copied to/from the user's address space.
  644          */
  645         size = IOCPARM_LEN(com);
  646         if ((size > IOCPARM_MAX) ||
  647             ((com & (IOC_VOID  | IOC_IN | IOC_OUT)) == 0) ||
  648 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
  649             ((com & IOC_OUT) && size == 0) ||
  650 #else
  651             ((com & (IOC_IN | IOC_OUT)) && size == 0) ||
  652 #endif
  653             ((com & IOC_VOID) && size > 0 && size != sizeof(int)))
  654                 return (ENOTTY);
  655 
  656         if (size > 0) {
  657                 if (com & IOC_VOID) {
  658                         /* Integer argument. */
  659                         arg = (intptr_t)uap->data;
  660                         data = (void *)&arg;
  661                         size = 0;
  662                 } else
  663                         data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
  664         } else
  665                 data = (void *)&uap->data;
  666         if (com & IOC_IN) {
  667                 error = copyin(uap->data, data, (u_int)size);
  668                 if (error) {
  669                         if (size > 0)
  670                                 free(data, M_IOCTLOPS);
  671                         return (error);
  672                 }
  673         } else if (com & IOC_OUT) {
  674                 /*
  675                  * Zero the buffer so the user always
  676                  * gets back something deterministic.
  677                  */
  678                 bzero(data, size);
  679         }
  680 
  681         error = kern_ioctl(td, uap->fd, com, data);
  682 
  683         if (error == 0 && (com & IOC_OUT))
  684                 error = copyout(data, uap->data, (u_int)size);
  685 
  686         if (size > 0)
  687                 free(data, M_IOCTLOPS);
  688         return (error);
  689 }
  690 
  691 int
  692 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data)
  693 {
  694         struct file *fp;
  695         struct filedesc *fdp;
  696         int error;
  697         int tmp;
  698 
  699         AUDIT_ARG_FD(fd);
  700         AUDIT_ARG_CMD(com);
  701         if ((error = fget(td, fd, CAP_IOCTL, &fp)) != 0)
  702                 return (error);
  703         if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
  704                 fdrop(fp, td);
  705                 return (EBADF);
  706         }
  707         fdp = td->td_proc->p_fd;
  708         switch (com) {
  709         case FIONCLEX:
  710                 FILEDESC_XLOCK(fdp);
  711                 fdp->fd_ofileflags[fd] &= ~UF_EXCLOSE;
  712                 FILEDESC_XUNLOCK(fdp);
  713                 goto out;
  714         case FIOCLEX:
  715                 FILEDESC_XLOCK(fdp);
  716                 fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
  717                 FILEDESC_XUNLOCK(fdp);
  718                 goto out;
  719         case FIONBIO:
  720                 if ((tmp = *(int *)data))
  721                         atomic_set_int(&fp->f_flag, FNONBLOCK);
  722                 else
  723                         atomic_clear_int(&fp->f_flag, FNONBLOCK);
  724                 data = (void *)&tmp;
  725                 break;
  726         case FIOASYNC:
  727                 if ((tmp = *(int *)data))
  728                         atomic_set_int(&fp->f_flag, FASYNC);
  729                 else
  730                         atomic_clear_int(&fp->f_flag, FASYNC);
  731                 data = (void *)&tmp;
  732                 break;
  733         }
  734 
  735         error = fo_ioctl(fp, com, data, td->td_ucred, td);
  736 out:
  737         fdrop(fp, td);
  738         return (error);
  739 }
  740 
  741 int
  742 poll_no_poll(int events)
  743 {
  744         /*
  745          * Return true for read/write.  If the user asked for something
  746          * special, return POLLNVAL, so that clients have a way of
  747          * determining reliably whether or not the extended
  748          * functionality is present without hard-coding knowledge
  749          * of specific filesystem implementations.
  750          */
  751         if (events & ~POLLSTANDARD)
  752                 return (POLLNVAL);
  753 
  754         return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
  755 }
  756 
  757 int
  758 sys_pselect(struct thread *td, struct pselect_args *uap)
  759 {
  760         struct timespec ts;
  761         struct timeval tv, *tvp;
  762         sigset_t set, *uset;
  763         int error;
  764 
  765         if (uap->ts != NULL) {
  766                 error = copyin(uap->ts, &ts, sizeof(ts));
  767                 if (error != 0)
  768                     return (error);
  769                 TIMESPEC_TO_TIMEVAL(&tv, &ts);
  770                 tvp = &tv;
  771         } else
  772                 tvp = NULL;
  773         if (uap->sm != NULL) {
  774                 error = copyin(uap->sm, &set, sizeof(set));
  775                 if (error != 0)
  776                         return (error);
  777                 uset = &set;
  778         } else
  779                 uset = NULL;
  780         return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
  781             uset, NFDBITS));
  782 }
  783 
  784 int
  785 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex,
  786     struct timeval *tvp, sigset_t *uset, int abi_nfdbits)
  787 {
  788         int error;
  789 
  790         if (uset != NULL) {
  791                 error = kern_sigprocmask(td, SIG_SETMASK, uset,
  792                     &td->td_oldsigmask, 0);
  793                 if (error != 0)
  794                         return (error);
  795                 td->td_pflags |= TDP_OLDMASK;
  796                 /*
  797                  * Make sure that ast() is called on return to
  798                  * usermode and TDP_OLDMASK is cleared, restoring old
  799                  * sigmask.
  800                  */
  801                 thread_lock(td);
  802                 td->td_flags |= TDF_ASTPENDING;
  803                 thread_unlock(td);
  804         }
  805         error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits);
  806         return (error);
  807 }
  808 
  809 #ifndef _SYS_SYSPROTO_H_
  810 struct select_args {
  811         int     nd;
  812         fd_set  *in, *ou, *ex;
  813         struct  timeval *tv;
  814 };
  815 #endif
  816 int
  817 sys_select(struct thread *td, struct select_args *uap)
  818 {
  819         struct timeval tv, *tvp;
  820         int error;
  821 
  822         if (uap->tv != NULL) {
  823                 error = copyin(uap->tv, &tv, sizeof(tv));
  824                 if (error)
  825                         return (error);
  826                 tvp = &tv;
  827         } else
  828                 tvp = NULL;
  829 
  830         return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
  831             NFDBITS));
  832 }
  833 
  834 /*
  835  * In the unlikely case when user specified n greater then the last
  836  * open file descriptor, check that no bits are set after the last
  837  * valid fd.  We must return EBADF if any is set.
  838  *
  839  * There are applications that rely on the behaviour.
  840  *
  841  * nd is fd_lastfile + 1.
  842  */
  843 static int
  844 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits)
  845 {
  846         char *addr, *oaddr;
  847         int b, i, res;
  848         uint8_t bits;
  849 
  850         if (nd >= ndu || fd_in == NULL)
  851                 return (0);
  852 
  853         oaddr = NULL;
  854         bits = 0; /* silence gcc */
  855         for (i = nd; i < ndu; i++) {
  856                 b = i / NBBY;
  857 #if BYTE_ORDER == LITTLE_ENDIAN
  858                 addr = (char *)fd_in + b;
  859 #else
  860                 addr = (char *)fd_in;
  861                 if (abi_nfdbits == NFDBITS) {
  862                         addr += rounddown(b, sizeof(fd_mask)) +
  863                             sizeof(fd_mask) - 1 - b % sizeof(fd_mask);
  864                 } else {
  865                         addr += rounddown(b, sizeof(uint32_t)) +
  866                             sizeof(uint32_t) - 1 - b % sizeof(uint32_t);
  867                 }
  868 #endif
  869                 if (addr != oaddr) {
  870                         res = fubyte(addr);
  871                         if (res == -1)
  872                                 return (EFAULT);
  873                         oaddr = addr;
  874                         bits = res;
  875                 }
  876                 if ((bits & (1 << (i % NBBY))) != 0)
  877                         return (EBADF);
  878         }
  879         return (0);
  880 }
  881 
  882 int
  883 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou,
  884     fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits)
  885 {
  886         struct filedesc *fdp;
  887         /*
  888          * The magic 2048 here is chosen to be just enough for FD_SETSIZE
  889          * infds with the new FD_SETSIZE of 1024, and more than enough for
  890          * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE
  891          * of 256.
  892          */
  893         fd_mask s_selbits[howmany(2048, NFDBITS)];
  894         fd_mask *ibits[3], *obits[3], *selbits, *sbp;
  895         struct timeval atv, rtv, ttv;
  896         int error, lf, ndu, timo;
  897         u_int nbufbytes, ncpbytes, ncpubytes, nfdbits;
  898 
  899         if (nd < 0)
  900                 return (EINVAL);
  901         fdp = td->td_proc->p_fd;
  902         ndu = nd;
  903         lf = fdp->fd_lastfile;
  904         if (nd > lf + 1)
  905                 nd = lf + 1;
  906 
  907         error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits);
  908         if (error != 0)
  909                 return (error);
  910         error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits);
  911         if (error != 0)
  912                 return (error);
  913         error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits);
  914         if (error != 0)
  915                 return (error);
  916 
  917         /*
  918          * Allocate just enough bits for the non-null fd_sets.  Use the
  919          * preallocated auto buffer if possible.
  920          */
  921         nfdbits = roundup(nd, NFDBITS);
  922         ncpbytes = nfdbits / NBBY;
  923         ncpubytes = roundup(nd, abi_nfdbits) / NBBY;
  924         nbufbytes = 0;
  925         if (fd_in != NULL)
  926                 nbufbytes += 2 * ncpbytes;
  927         if (fd_ou != NULL)
  928                 nbufbytes += 2 * ncpbytes;
  929         if (fd_ex != NULL)
  930                 nbufbytes += 2 * ncpbytes;
  931         if (nbufbytes <= sizeof s_selbits)
  932                 selbits = &s_selbits[0];
  933         else
  934                 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK);
  935 
  936         /*
  937          * Assign pointers into the bit buffers and fetch the input bits.
  938          * Put the output buffers together so that they can be bzeroed
  939          * together.
  940          */
  941         sbp = selbits;
  942 #define getbits(name, x) \
  943         do {                                                            \
  944                 if (name == NULL) {                                     \
  945                         ibits[x] = NULL;                                \
  946                         obits[x] = NULL;                                \
  947                 } else {                                                \
  948                         ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp;   \
  949                         obits[x] = sbp;                                 \
  950                         sbp += ncpbytes / sizeof *sbp;                  \
  951                         error = copyin(name, ibits[x], ncpubytes);      \
  952                         if (error != 0)                                 \
  953                                 goto done;                              \
  954                         bzero((char *)ibits[x] + ncpubytes,             \
  955                             ncpbytes - ncpubytes);                      \
  956                 }                                                       \
  957         } while (0)
  958         getbits(fd_in, 0);
  959         getbits(fd_ou, 1);
  960         getbits(fd_ex, 2);
  961 #undef  getbits
  962 
  963 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__)
  964         /*
  965          * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS,
  966          * we are running under 32-bit emulation. This should be more
  967          * generic.
  968          */
  969 #define swizzle_fdset(bits)                                             \
  970         if (abi_nfdbits != NFDBITS && bits != NULL) {                   \
  971                 int i;                                                  \
  972                 for (i = 0; i < ncpbytes / sizeof *sbp; i++)            \
  973                         bits[i] = (bits[i] >> 32) | (bits[i] << 32);    \
  974         }
  975 #else
  976 #define swizzle_fdset(bits)
  977 #endif
  978 
  979         /* Make sure the bit order makes it through an ABI transition */
  980         swizzle_fdset(ibits[0]);
  981         swizzle_fdset(ibits[1]);
  982         swizzle_fdset(ibits[2]);
  983         
  984         if (nbufbytes != 0)
  985                 bzero(selbits, nbufbytes / 2);
  986 
  987         if (tvp != NULL) {
  988                 atv = *tvp;
  989                 if (itimerfix(&atv)) {
  990                         error = EINVAL;
  991                         goto done;
  992                 }
  993                 getmicrouptime(&rtv);
  994                 timevaladd(&atv, &rtv);
  995         } else {
  996                 atv.tv_sec = 0;
  997                 atv.tv_usec = 0;
  998         }
  999         timo = 0;
 1000         seltdinit(td);
 1001         /* Iterate until the timeout expires or descriptors become ready. */
 1002         for (;;) {
 1003                 error = selscan(td, ibits, obits, nd);
 1004                 if (error || td->td_retval[0] != 0)
 1005                         break;
 1006                 if (atv.tv_sec || atv.tv_usec) {
 1007                         getmicrouptime(&rtv);
 1008                         if (timevalcmp(&rtv, &atv, >=))
 1009                                 break;
 1010                         ttv = atv;
 1011                         timevalsub(&ttv, &rtv);
 1012                         timo = ttv.tv_sec > 24 * 60 * 60 ?
 1013                             24 * 60 * 60 * hz : tvtohz(&ttv);
 1014                 }
 1015                 error = seltdwait(td, timo);
 1016                 if (error)
 1017                         break;
 1018                 error = selrescan(td, ibits, obits);
 1019                 if (error || td->td_retval[0] != 0)
 1020                         break;
 1021         }
 1022         seltdclear(td);
 1023 
 1024 done:
 1025         /* select is not restarted after signals... */
 1026         if (error == ERESTART)
 1027                 error = EINTR;
 1028         if (error == EWOULDBLOCK)
 1029                 error = 0;
 1030 
 1031         /* swizzle bit order back, if necessary */
 1032         swizzle_fdset(obits[0]);
 1033         swizzle_fdset(obits[1]);
 1034         swizzle_fdset(obits[2]);
 1035 #undef swizzle_fdset
 1036 
 1037 #define putbits(name, x) \
 1038         if (name && (error2 = copyout(obits[x], name, ncpubytes))) \
 1039                 error = error2;
 1040         if (error == 0) {
 1041                 int error2;
 1042 
 1043                 putbits(fd_in, 0);
 1044                 putbits(fd_ou, 1);
 1045                 putbits(fd_ex, 2);
 1046 #undef putbits
 1047         }
 1048         if (selbits != &s_selbits[0])
 1049                 free(selbits, M_SELECT);
 1050 
 1051         return (error);
 1052 }
 1053 /* 
 1054  * Convert a select bit set to poll flags.
 1055  *
 1056  * The backend always returns POLLHUP/POLLERR if appropriate and we
 1057  * return this as a set bit in any set.
 1058  */
 1059 static int select_flags[3] = {
 1060     POLLRDNORM | POLLHUP | POLLERR,
 1061     POLLWRNORM | POLLHUP | POLLERR,
 1062     POLLRDBAND | POLLERR
 1063 };
 1064 
 1065 /*
 1066  * Compute the fo_poll flags required for a fd given by the index and
 1067  * bit position in the fd_mask array.
 1068  */
 1069 static __inline int
 1070 selflags(fd_mask **ibits, int idx, fd_mask bit)
 1071 {
 1072         int flags;
 1073         int msk;
 1074 
 1075         flags = 0;
 1076         for (msk = 0; msk < 3; msk++) {
 1077                 if (ibits[msk] == NULL)
 1078                         continue;
 1079                 if ((ibits[msk][idx] & bit) == 0)
 1080                         continue;
 1081                 flags |= select_flags[msk];
 1082         }
 1083         return (flags);
 1084 }
 1085 
 1086 /*
 1087  * Set the appropriate output bits given a mask of fired events and the
 1088  * input bits originally requested.
 1089  */
 1090 static __inline int
 1091 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events)
 1092 {
 1093         int msk;
 1094         int n;
 1095 
 1096         n = 0;
 1097         for (msk = 0; msk < 3; msk++) {
 1098                 if ((events & select_flags[msk]) == 0)
 1099                         continue;
 1100                 if (ibits[msk] == NULL)
 1101                         continue;
 1102                 if ((ibits[msk][idx] & bit) == 0)
 1103                         continue;
 1104                 /*
 1105                  * XXX Check for a duplicate set.  This can occur because a
 1106                  * socket calls selrecord() twice for each poll() call
 1107                  * resulting in two selfds per real fd.  selrescan() will
 1108                  * call selsetbits twice as a result.
 1109                  */
 1110                 if ((obits[msk][idx] & bit) != 0)
 1111                         continue;
 1112                 obits[msk][idx] |= bit;
 1113                 n++;
 1114         }
 1115 
 1116         return (n);
 1117 }
 1118 
 1119 static __inline int
 1120 getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp)
 1121 {
 1122         struct file *fp;
 1123 #ifdef CAPABILITIES
 1124         struct file *fp_fromcap;
 1125         int error;
 1126 #endif
 1127 
 1128         if ((fp = fget_unlocked(fdp, fd)) == NULL)
 1129                 return (EBADF);
 1130 #ifdef CAPABILITIES
 1131         /*
 1132          * If the file descriptor is for a capability, test rights and use
 1133          * the file descriptor references by the capability.
 1134          */
 1135         error = cap_funwrap(fp, CAP_POLL_EVENT, &fp_fromcap);
 1136         if (error) {
 1137                 fdrop(fp, curthread);
 1138                 return (error);
 1139         }
 1140         if (fp != fp_fromcap) {
 1141                 fhold(fp_fromcap);
 1142                 fdrop(fp, curthread);
 1143                 fp = fp_fromcap;
 1144         }
 1145 #endif /* CAPABILITIES */
 1146         *fpp = fp;
 1147         return (0);
 1148 }
 1149 
 1150 /*
 1151  * Traverse the list of fds attached to this thread's seltd and check for
 1152  * completion.
 1153  */
 1154 static int
 1155 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits)
 1156 {
 1157         struct filedesc *fdp;
 1158         struct selinfo *si;
 1159         struct seltd *stp;
 1160         struct selfd *sfp;
 1161         struct selfd *sfn;
 1162         struct file *fp;
 1163         fd_mask bit;
 1164         int fd, ev, n, idx;
 1165         int error;
 1166 
 1167         fdp = td->td_proc->p_fd;
 1168         stp = td->td_sel;
 1169         n = 0;
 1170         STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
 1171                 fd = (int)(uintptr_t)sfp->sf_cookie;
 1172                 si = sfp->sf_si;
 1173                 selfdfree(stp, sfp);
 1174                 /* If the selinfo wasn't cleared the event didn't fire. */
 1175                 if (si != NULL)
 1176                         continue;
 1177                 error = getselfd_cap(fdp, fd, &fp);
 1178                 if (error)
 1179                         return (error);
 1180                 idx = fd / NFDBITS;
 1181                 bit = (fd_mask)1 << (fd % NFDBITS);
 1182                 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td);
 1183                 fdrop(fp, td);
 1184                 if (ev != 0)
 1185                         n += selsetbits(ibits, obits, idx, bit, ev);
 1186         }
 1187         stp->st_flags = 0;
 1188         td->td_retval[0] = n;
 1189         return (0);
 1190 }
 1191 
 1192 /*
 1193  * Perform the initial filedescriptor scan and register ourselves with
 1194  * each selinfo.
 1195  */
 1196 static int
 1197 selscan(td, ibits, obits, nfd)
 1198         struct thread *td;
 1199         fd_mask **ibits, **obits;
 1200         int nfd;
 1201 {
 1202         struct filedesc *fdp;
 1203         struct file *fp;
 1204         fd_mask bit;
 1205         int ev, flags, end, fd;
 1206         int n, idx;
 1207         int error;
 1208 
 1209         fdp = td->td_proc->p_fd;
 1210         n = 0;
 1211         for (idx = 0, fd = 0; fd < nfd; idx++) {
 1212                 end = imin(fd + NFDBITS, nfd);
 1213                 for (bit = 1; fd < end; bit <<= 1, fd++) {
 1214                         /* Compute the list of events we're interested in. */
 1215                         flags = selflags(ibits, idx, bit);
 1216                         if (flags == 0)
 1217                                 continue;
 1218                         error = getselfd_cap(fdp, fd, &fp);
 1219                         if (error)
 1220                                 return (error);
 1221                         selfdalloc(td, (void *)(uintptr_t)fd);
 1222                         ev = fo_poll(fp, flags, td->td_ucred, td);
 1223                         fdrop(fp, td);
 1224                         if (ev != 0)
 1225                                 n += selsetbits(ibits, obits, idx, bit, ev);
 1226                 }
 1227         }
 1228 
 1229         td->td_retval[0] = n;
 1230         return (0);
 1231 }
 1232 
 1233 #ifndef _SYS_SYSPROTO_H_
 1234 struct poll_args {
 1235         struct pollfd *fds;
 1236         u_int   nfds;
 1237         int     timeout;
 1238 };
 1239 #endif
 1240 int
 1241 sys_poll(td, uap)
 1242         struct thread *td;
 1243         struct poll_args *uap;
 1244 {
 1245         struct pollfd *bits;
 1246         struct pollfd smallbits[32];
 1247         struct timeval atv, rtv, ttv;
 1248         int error = 0, timo;
 1249         u_int nfds;
 1250         size_t ni;
 1251 
 1252         nfds = uap->nfds;
 1253         if (nfds > maxfilesperproc && nfds > FD_SETSIZE) 
 1254                 return (EINVAL);
 1255         ni = nfds * sizeof(struct pollfd);
 1256         if (ni > sizeof(smallbits))
 1257                 bits = malloc(ni, M_TEMP, M_WAITOK);
 1258         else
 1259                 bits = smallbits;
 1260         error = copyin(uap->fds, bits, ni);
 1261         if (error)
 1262                 goto done;
 1263         if (uap->timeout != INFTIM) {
 1264                 atv.tv_sec = uap->timeout / 1000;
 1265                 atv.tv_usec = (uap->timeout % 1000) * 1000;
 1266                 if (itimerfix(&atv)) {
 1267                         error = EINVAL;
 1268                         goto done;
 1269                 }
 1270                 getmicrouptime(&rtv);
 1271                 timevaladd(&atv, &rtv);
 1272         } else {
 1273                 atv.tv_sec = 0;
 1274                 atv.tv_usec = 0;
 1275         }
 1276         timo = 0;
 1277         seltdinit(td);
 1278         /* Iterate until the timeout expires or descriptors become ready. */
 1279         for (;;) {
 1280                 error = pollscan(td, bits, nfds);
 1281                 if (error || td->td_retval[0] != 0)
 1282                         break;
 1283                 if (atv.tv_sec || atv.tv_usec) {
 1284                         getmicrouptime(&rtv);
 1285                         if (timevalcmp(&rtv, &atv, >=))
 1286                                 break;
 1287                         ttv = atv;
 1288                         timevalsub(&ttv, &rtv);
 1289                         timo = ttv.tv_sec > 24 * 60 * 60 ?
 1290                             24 * 60 * 60 * hz : tvtohz(&ttv);
 1291                 }
 1292                 error = seltdwait(td, timo);
 1293                 if (error)
 1294                         break;
 1295                 error = pollrescan(td);
 1296                 if (error || td->td_retval[0] != 0)
 1297                         break;
 1298         }
 1299         seltdclear(td);
 1300 
 1301 done:
 1302         /* poll is not restarted after signals... */
 1303         if (error == ERESTART)
 1304                 error = EINTR;
 1305         if (error == EWOULDBLOCK)
 1306                 error = 0;
 1307         if (error == 0) {
 1308                 error = pollout(td, bits, uap->fds, nfds);
 1309                 if (error)
 1310                         goto out;
 1311         }
 1312 out:
 1313         if (ni > sizeof(smallbits))
 1314                 free(bits, M_TEMP);
 1315         return (error);
 1316 }
 1317 
 1318 static int
 1319 pollrescan(struct thread *td)
 1320 {
 1321         struct seltd *stp;
 1322         struct selfd *sfp;
 1323         struct selfd *sfn;
 1324         struct selinfo *si;
 1325         struct filedesc *fdp;
 1326         struct file *fp;
 1327         struct pollfd *fd;
 1328         int n;
 1329 
 1330         n = 0;
 1331         fdp = td->td_proc->p_fd;
 1332         stp = td->td_sel;
 1333         FILEDESC_SLOCK(fdp);
 1334         STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
 1335                 fd = (struct pollfd *)sfp->sf_cookie;
 1336                 si = sfp->sf_si;
 1337                 selfdfree(stp, sfp);
 1338                 /* If the selinfo wasn't cleared the event didn't fire. */
 1339                 if (si != NULL)
 1340                         continue;
 1341                 fp = fdp->fd_ofiles[fd->fd];
 1342 #ifdef CAPABILITIES
 1343                 if ((fp == NULL)
 1344                     || (cap_funwrap(fp, CAP_POLL_EVENT, &fp) != 0)) {
 1345 #else
 1346                 if (fp == NULL) {
 1347 #endif
 1348                         fd->revents = POLLNVAL;
 1349                         n++;
 1350                         continue;
 1351                 }
 1352 
 1353                 /*
 1354                  * Note: backend also returns POLLHUP and
 1355                  * POLLERR if appropriate.
 1356                  */
 1357                 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td);
 1358                 if (fd->revents != 0)
 1359                         n++;
 1360         }
 1361         FILEDESC_SUNLOCK(fdp);
 1362         stp->st_flags = 0;
 1363         td->td_retval[0] = n;
 1364         return (0);
 1365 }
 1366 
 1367 
 1368 static int
 1369 pollout(td, fds, ufds, nfd)
 1370         struct thread *td;
 1371         struct pollfd *fds;
 1372         struct pollfd *ufds;
 1373         u_int nfd;
 1374 {
 1375         int error = 0;
 1376         u_int i = 0;
 1377         u_int n = 0;
 1378 
 1379         for (i = 0; i < nfd; i++) {
 1380                 error = copyout(&fds->revents, &ufds->revents,
 1381                     sizeof(ufds->revents));
 1382                 if (error)
 1383                         return (error);
 1384                 if (fds->revents != 0)
 1385                         n++;
 1386                 fds++;
 1387                 ufds++;
 1388         }
 1389         td->td_retval[0] = n;
 1390         return (0);
 1391 }
 1392 
 1393 static int
 1394 pollscan(td, fds, nfd)
 1395         struct thread *td;
 1396         struct pollfd *fds;
 1397         u_int nfd;
 1398 {
 1399         struct filedesc *fdp = td->td_proc->p_fd;
 1400         int i;
 1401         struct file *fp;
 1402         int n = 0;
 1403 
 1404         FILEDESC_SLOCK(fdp);
 1405         for (i = 0; i < nfd; i++, fds++) {
 1406                 if (fds->fd >= fdp->fd_nfiles) {
 1407                         fds->revents = POLLNVAL;
 1408                         n++;
 1409                 } else if (fds->fd < 0) {
 1410                         fds->revents = 0;
 1411                 } else {
 1412                         fp = fdp->fd_ofiles[fds->fd];
 1413 #ifdef CAPABILITIES
 1414                         if ((fp == NULL)
 1415                             || (cap_funwrap(fp, CAP_POLL_EVENT, &fp) != 0)) {
 1416 #else
 1417                         if (fp == NULL) {
 1418 #endif
 1419                                 fds->revents = POLLNVAL;
 1420                                 n++;
 1421                         } else {
 1422                                 /*
 1423                                  * Note: backend also returns POLLHUP and
 1424                                  * POLLERR if appropriate.
 1425                                  */
 1426                                 selfdalloc(td, fds);
 1427                                 fds->revents = fo_poll(fp, fds->events,
 1428                                     td->td_ucred, td);
 1429                                 /*
 1430                                  * POSIX requires POLLOUT to be never
 1431                                  * set simultaneously with POLLHUP.
 1432                                  */
 1433                                 if ((fds->revents & POLLHUP) != 0)
 1434                                         fds->revents &= ~POLLOUT;
 1435 
 1436                                 if (fds->revents != 0)
 1437                                         n++;
 1438                         }
 1439                 }
 1440         }
 1441         FILEDESC_SUNLOCK(fdp);
 1442         td->td_retval[0] = n;
 1443         return (0);
 1444 }
 1445 
 1446 /*
 1447  * OpenBSD poll system call.
 1448  *
 1449  * XXX this isn't quite a true representation..  OpenBSD uses select ops.
 1450  */
 1451 #ifndef _SYS_SYSPROTO_H_
 1452 struct openbsd_poll_args {
 1453         struct pollfd *fds;
 1454         u_int   nfds;
 1455         int     timeout;
 1456 };
 1457 #endif
 1458 int
 1459 sys_openbsd_poll(td, uap)
 1460         register struct thread *td;
 1461         register struct openbsd_poll_args *uap;
 1462 {
 1463         return (sys_poll(td, (struct poll_args *)uap));
 1464 }
 1465 
 1466 /*
 1467  * XXX This was created specifically to support netncp and netsmb.  This
 1468  * allows the caller to specify a socket to wait for events on.  It returns
 1469  * 0 if any events matched and an error otherwise.  There is no way to
 1470  * determine which events fired.
 1471  */
 1472 int
 1473 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td)
 1474 {
 1475         struct timeval atv, rtv, ttv;
 1476         int error, timo;
 1477 
 1478         if (tvp != NULL) {
 1479                 atv = *tvp;
 1480                 if (itimerfix(&atv))
 1481                         return (EINVAL);
 1482                 getmicrouptime(&rtv);
 1483                 timevaladd(&atv, &rtv);
 1484         } else {
 1485                 atv.tv_sec = 0;
 1486                 atv.tv_usec = 0;
 1487         }
 1488 
 1489         timo = 0;
 1490         seltdinit(td);
 1491         /*
 1492          * Iterate until the timeout expires or the socket becomes ready.
 1493          */
 1494         for (;;) {
 1495                 selfdalloc(td, NULL);
 1496                 error = sopoll(so, events, NULL, td);
 1497                 /* error here is actually the ready events. */
 1498                 if (error)
 1499                         return (0);
 1500                 if (atv.tv_sec || atv.tv_usec) {
 1501                         getmicrouptime(&rtv);
 1502                         if (timevalcmp(&rtv, &atv, >=)) {
 1503                                 seltdclear(td);
 1504                                 return (EWOULDBLOCK);
 1505                         }
 1506                         ttv = atv;
 1507                         timevalsub(&ttv, &rtv);
 1508                         timo = ttv.tv_sec > 24 * 60 * 60 ?
 1509                             24 * 60 * 60 * hz : tvtohz(&ttv);
 1510                 }
 1511                 error = seltdwait(td, timo);
 1512                 seltdclear(td);
 1513                 if (error)
 1514                         break;
 1515         }
 1516         /* XXX Duplicates ncp/smb behavior. */
 1517         if (error == ERESTART)
 1518                 error = 0;
 1519         return (error);
 1520 }
 1521 
 1522 /*
 1523  * Preallocate two selfds associated with 'cookie'.  Some fo_poll routines
 1524  * have two select sets, one for read and another for write.
 1525  */
 1526 static void
 1527 selfdalloc(struct thread *td, void *cookie)
 1528 {
 1529         struct seltd *stp;
 1530 
 1531         stp = td->td_sel;
 1532         if (stp->st_free1 == NULL)
 1533                 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
 1534         stp->st_free1->sf_td = stp;
 1535         stp->st_free1->sf_cookie = cookie;
 1536         if (stp->st_free2 == NULL)
 1537                 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
 1538         stp->st_free2->sf_td = stp;
 1539         stp->st_free2->sf_cookie = cookie;
 1540 }
 1541 
 1542 static void
 1543 selfdfree(struct seltd *stp, struct selfd *sfp)
 1544 {
 1545         STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link);
 1546         mtx_lock(sfp->sf_mtx);
 1547         if (sfp->sf_si)
 1548                 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads);
 1549         mtx_unlock(sfp->sf_mtx);
 1550         uma_zfree(selfd_zone, sfp);
 1551 }
 1552 
 1553 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */
 1554 void
 1555 seldrain(sip)
 1556         struct selinfo *sip;
 1557 {
 1558 
 1559         /*
 1560          * This feature is already provided by doselwakeup(), thus it is
 1561          * enough to go for it.
 1562          * Eventually, the context, should take care to avoid races
 1563          * between thread calling select()/poll() and file descriptor
 1564          * detaching, but, again, the races are just the same as
 1565          * selwakeup().
 1566          */
 1567         doselwakeup(sip, -1);
 1568 }
 1569 
 1570 /*
 1571  * Record a select request.
 1572  */
 1573 void
 1574 selrecord(selector, sip)
 1575         struct thread *selector;
 1576         struct selinfo *sip;
 1577 {
 1578         struct selfd *sfp;
 1579         struct seltd *stp;
 1580         struct mtx *mtxp;
 1581 
 1582         stp = selector->td_sel;
 1583         /*
 1584          * Don't record when doing a rescan.
 1585          */
 1586         if (stp->st_flags & SELTD_RESCAN)
 1587                 return;
 1588         /*
 1589          * Grab one of the preallocated descriptors.
 1590          */
 1591         sfp = NULL;
 1592         if ((sfp = stp->st_free1) != NULL)
 1593                 stp->st_free1 = NULL;
 1594         else if ((sfp = stp->st_free2) != NULL)
 1595                 stp->st_free2 = NULL;
 1596         else
 1597                 panic("selrecord: No free selfd on selq");
 1598         mtxp = sip->si_mtx;
 1599         if (mtxp == NULL)
 1600                 mtxp = mtx_pool_find(mtxpool_select, sip);
 1601         /*
 1602          * Initialize the sfp and queue it in the thread.
 1603          */
 1604         sfp->sf_si = sip;
 1605         sfp->sf_mtx = mtxp;
 1606         STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link);
 1607         /*
 1608          * Now that we've locked the sip, check for initialization.
 1609          */
 1610         mtx_lock(mtxp);
 1611         if (sip->si_mtx == NULL) {
 1612                 sip->si_mtx = mtxp;
 1613                 TAILQ_INIT(&sip->si_tdlist);
 1614         }
 1615         /*
 1616          * Add this thread to the list of selfds listening on this selinfo.
 1617          */
 1618         TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads);
 1619         mtx_unlock(sip->si_mtx);
 1620 }
 1621 
 1622 /* Wake up a selecting thread. */
 1623 void
 1624 selwakeup(sip)
 1625         struct selinfo *sip;
 1626 {
 1627         doselwakeup(sip, -1);
 1628 }
 1629 
 1630 /* Wake up a selecting thread, and set its priority. */
 1631 void
 1632 selwakeuppri(sip, pri)
 1633         struct selinfo *sip;
 1634         int pri;
 1635 {
 1636         doselwakeup(sip, pri);
 1637 }
 1638 
 1639 /*
 1640  * Do a wakeup when a selectable event occurs.
 1641  */
 1642 static void
 1643 doselwakeup(sip, pri)
 1644         struct selinfo *sip;
 1645         int pri;
 1646 {
 1647         struct selfd *sfp;
 1648         struct selfd *sfn;
 1649         struct seltd *stp;
 1650 
 1651         /* If it's not initialized there can't be any waiters. */
 1652         if (sip->si_mtx == NULL)
 1653                 return;
 1654         /*
 1655          * Locking the selinfo locks all selfds associated with it.
 1656          */
 1657         mtx_lock(sip->si_mtx);
 1658         TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) {
 1659                 /*
 1660                  * Once we remove this sfp from the list and clear the
 1661                  * sf_si seltdclear will know to ignore this si.
 1662                  */
 1663                 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads);
 1664                 sfp->sf_si = NULL;
 1665                 stp = sfp->sf_td;
 1666                 mtx_lock(&stp->st_mtx);
 1667                 stp->st_flags |= SELTD_PENDING;
 1668                 cv_broadcastpri(&stp->st_wait, pri);
 1669                 mtx_unlock(&stp->st_mtx);
 1670         }
 1671         mtx_unlock(sip->si_mtx);
 1672 }
 1673 
 1674 static void
 1675 seltdinit(struct thread *td)
 1676 {
 1677         struct seltd *stp;
 1678 
 1679         if ((stp = td->td_sel) != NULL)
 1680                 goto out;
 1681         td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO);
 1682         mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF);
 1683         cv_init(&stp->st_wait, "select");
 1684 out:
 1685         stp->st_flags = 0;
 1686         STAILQ_INIT(&stp->st_selq);
 1687 }
 1688 
 1689 static int
 1690 seltdwait(struct thread *td, int timo)
 1691 {
 1692         struct seltd *stp;
 1693         int error;
 1694 
 1695         stp = td->td_sel;
 1696         /*
 1697          * An event of interest may occur while we do not hold the seltd
 1698          * locked so check the pending flag before we sleep.
 1699          */
 1700         mtx_lock(&stp->st_mtx);
 1701         /*
 1702          * Any further calls to selrecord will be a rescan.
 1703          */
 1704         stp->st_flags |= SELTD_RESCAN;
 1705         if (stp->st_flags & SELTD_PENDING) {
 1706                 mtx_unlock(&stp->st_mtx);
 1707                 return (0);
 1708         }
 1709         if (timo > 0)
 1710                 error = cv_timedwait_sig(&stp->st_wait, &stp->st_mtx, timo);
 1711         else
 1712                 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx);
 1713         mtx_unlock(&stp->st_mtx);
 1714 
 1715         return (error);
 1716 }
 1717 
 1718 void
 1719 seltdfini(struct thread *td)
 1720 {
 1721         struct seltd *stp;
 1722 
 1723         stp = td->td_sel;
 1724         if (stp == NULL)
 1725                 return;
 1726         if (stp->st_free1)
 1727                 uma_zfree(selfd_zone, stp->st_free1);
 1728         if (stp->st_free2)
 1729                 uma_zfree(selfd_zone, stp->st_free2);
 1730         td->td_sel = NULL;
 1731         free(stp, M_SELECT);
 1732 }
 1733 
 1734 /*
 1735  * Remove the references to the thread from all of the objects we were
 1736  * polling.
 1737  */
 1738 static void
 1739 seltdclear(struct thread *td)
 1740 {
 1741         struct seltd *stp;
 1742         struct selfd *sfp;
 1743         struct selfd *sfn;
 1744 
 1745         stp = td->td_sel;
 1746         STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn)
 1747                 selfdfree(stp, sfp);
 1748         stp->st_flags = 0;
 1749 }
 1750 
 1751 static void selectinit(void *);
 1752 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL);
 1753 static void
 1754 selectinit(void *dummy __unused)
 1755 {
 1756 
 1757         selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL,
 1758             NULL, NULL, UMA_ALIGN_PTR, 0);
 1759         mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF);
 1760 }

Cache object: 9df3e289e95ba6e1cf39dd061b425e84


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