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/10.2/sys/kern/sys_generic.c 280258 2015-03-19 13:37:36Z rwatson $");
   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/capsicum.h>
   48 #include <sys/filedesc.h>
   49 #include <sys/filio.h>
   50 #include <sys/fcntl.h>
   51 #include <sys/file.h>
   52 #include <sys/lock.h>
   53 #include <sys/proc.h>
   54 #include <sys/signalvar.h>
   55 #include <sys/socketvar.h>
   56 #include <sys/uio.h>
   57 #include <sys/kernel.h>
   58 #include <sys/ktr.h>
   59 #include <sys/limits.h>
   60 #include <sys/malloc.h>
   61 #include <sys/poll.h>
   62 #include <sys/resourcevar.h>
   63 #include <sys/selinfo.h>
   64 #include <sys/sleepqueue.h>
   65 #include <sys/syscallsubr.h>
   66 #include <sys/sysctl.h>
   67 #include <sys/sysent.h>
   68 #include <sys/vnode.h>
   69 #include <sys/bio.h>
   70 #include <sys/buf.h>
   71 #include <sys/condvar.h>
   72 #ifdef KTRACE
   73 #include <sys/ktrace.h>
   74 #endif
   75 
   76 #include <security/audit/audit.h>
   77 
   78 /*
   79  * The following macro defines how many bytes will be allocated from
   80  * the stack instead of memory allocated when passing the IOCTL data
   81  * structures from userspace and to the kernel. Some IOCTLs having
   82  * small data structures are used very frequently and this small
   83  * buffer on the stack gives a significant speedup improvement for
   84  * those requests. The value of this define should be greater or equal
   85  * to 64 bytes and should also be power of two. The data structure is
   86  * currently hard-aligned to a 8-byte boundary on the stack. This
   87  * should currently be sufficient for all supported platforms.
   88  */
   89 #define SYS_IOCTL_SMALL_SIZE    128     /* bytes */
   90 #define SYS_IOCTL_SMALL_ALIGN   8       /* bytes */
   91 
   92 int iosize_max_clamp = 1;
   93 SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW,
   94     &iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX");
   95 int devfs_iosize_max_clamp = 1;
   96 SYSCTL_INT(_debug, OID_AUTO, devfs_iosize_max_clamp, CTLFLAG_RW,
   97     &devfs_iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX for devices");
   98 
   99 /*
  100  * Assert that the return value of read(2) and write(2) syscalls fits
  101  * into a register.  If not, an architecture will need to provide the
  102  * usermode wrappers to reconstruct the result.
  103  */
  104 CTASSERT(sizeof(register_t) >= sizeof(size_t));
  105 
  106 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer");
  107 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer");
  108 MALLOC_DEFINE(M_IOV, "iov", "large iov's");
  109 
  110 static int      pollout(struct thread *, struct pollfd *, struct pollfd *,
  111                     u_int);
  112 static int      pollscan(struct thread *, struct pollfd *, u_int);
  113 static int      pollrescan(struct thread *);
  114 static int      selscan(struct thread *, fd_mask **, fd_mask **, int);
  115 static int      selrescan(struct thread *, fd_mask **, fd_mask **);
  116 static void     selfdalloc(struct thread *, void *);
  117 static void     selfdfree(struct seltd *, struct selfd *);
  118 static int      dofileread(struct thread *, int, struct file *, struct uio *,
  119                     off_t, int);
  120 static int      dofilewrite(struct thread *, int, struct file *, struct uio *,
  121                     off_t, int);
  122 static void     doselwakeup(struct selinfo *, int);
  123 static void     seltdinit(struct thread *);
  124 static int      seltdwait(struct thread *, sbintime_t, sbintime_t);
  125 static void     seltdclear(struct thread *);
  126 
  127 /*
  128  * One seltd per-thread allocated on demand as needed.
  129  *
  130  *      t - protected by st_mtx
  131  *      k - Only accessed by curthread or read-only
  132  */
  133 struct seltd {
  134         STAILQ_HEAD(, selfd)    st_selq;        /* (k) List of selfds. */
  135         struct selfd            *st_free1;      /* (k) free fd for read set. */
  136         struct selfd            *st_free2;      /* (k) free fd for write set. */
  137         struct mtx              st_mtx;         /* Protects struct seltd */
  138         struct cv               st_wait;        /* (t) Wait channel. */
  139         int                     st_flags;       /* (t) SELTD_ flags. */
  140 };
  141 
  142 #define SELTD_PENDING   0x0001                  /* We have pending events. */
  143 #define SELTD_RESCAN    0x0002                  /* Doing a rescan. */
  144 
  145 /*
  146  * One selfd allocated per-thread per-file-descriptor.
  147  *      f - protected by sf_mtx
  148  */
  149 struct selfd {
  150         STAILQ_ENTRY(selfd)     sf_link;        /* (k) fds owned by this td. */
  151         TAILQ_ENTRY(selfd)      sf_threads;     /* (f) fds on this selinfo. */
  152         struct selinfo          *sf_si;         /* (f) selinfo when linked. */
  153         struct mtx              *sf_mtx;        /* Pointer to selinfo mtx. */
  154         struct seltd            *sf_td;         /* (k) owning seltd. */
  155         void                    *sf_cookie;     /* (k) fd or pollfd. */
  156 };
  157 
  158 static uma_zone_t selfd_zone;
  159 static struct mtx_pool *mtxpool_select;
  160 
  161 #ifndef _SYS_SYSPROTO_H_
  162 struct read_args {
  163         int     fd;
  164         void    *buf;
  165         size_t  nbyte;
  166 };
  167 #endif
  168 int
  169 sys_read(td, uap)
  170         struct thread *td;
  171         struct read_args *uap;
  172 {
  173         struct uio auio;
  174         struct iovec aiov;
  175         int error;
  176 
  177         if (uap->nbyte > IOSIZE_MAX)
  178                 return (EINVAL);
  179         aiov.iov_base = uap->buf;
  180         aiov.iov_len = uap->nbyte;
  181         auio.uio_iov = &aiov;
  182         auio.uio_iovcnt = 1;
  183         auio.uio_resid = uap->nbyte;
  184         auio.uio_segflg = UIO_USERSPACE;
  185         error = kern_readv(td, uap->fd, &auio);
  186         return(error);
  187 }
  188 
  189 /*
  190  * Positioned read system call
  191  */
  192 #ifndef _SYS_SYSPROTO_H_
  193 struct pread_args {
  194         int     fd;
  195         void    *buf;
  196         size_t  nbyte;
  197         int     pad;
  198         off_t   offset;
  199 };
  200 #endif
  201 int
  202 sys_pread(td, uap)
  203         struct thread *td;
  204         struct pread_args *uap;
  205 {
  206         struct uio auio;
  207         struct iovec aiov;
  208         int error;
  209 
  210         if (uap->nbyte > IOSIZE_MAX)
  211                 return (EINVAL);
  212         aiov.iov_base = uap->buf;
  213         aiov.iov_len = uap->nbyte;
  214         auio.uio_iov = &aiov;
  215         auio.uio_iovcnt = 1;
  216         auio.uio_resid = uap->nbyte;
  217         auio.uio_segflg = UIO_USERSPACE;
  218         error = kern_preadv(td, uap->fd, &auio, uap->offset);
  219         return(error);
  220 }
  221 
  222 int
  223 freebsd6_pread(td, uap)
  224         struct thread *td;
  225         struct freebsd6_pread_args *uap;
  226 {
  227         struct pread_args oargs;
  228 
  229         oargs.fd = uap->fd;
  230         oargs.buf = uap->buf;
  231         oargs.nbyte = uap->nbyte;
  232         oargs.offset = uap->offset;
  233         return (sys_pread(td, &oargs));
  234 }
  235 
  236 /*
  237  * Scatter read system call.
  238  */
  239 #ifndef _SYS_SYSPROTO_H_
  240 struct readv_args {
  241         int     fd;
  242         struct  iovec *iovp;
  243         u_int   iovcnt;
  244 };
  245 #endif
  246 int
  247 sys_readv(struct thread *td, struct readv_args *uap)
  248 {
  249         struct uio *auio;
  250         int error;
  251 
  252         error = copyinuio(uap->iovp, uap->iovcnt, &auio);
  253         if (error)
  254                 return (error);
  255         error = kern_readv(td, uap->fd, auio);
  256         free(auio, M_IOV);
  257         return (error);
  258 }
  259 
  260 int
  261 kern_readv(struct thread *td, int fd, struct uio *auio)
  262 {
  263         struct file *fp;
  264         cap_rights_t rights;
  265         int error;
  266 
  267         error = fget_read(td, fd, cap_rights_init(&rights, CAP_READ), &fp);
  268         if (error)
  269                 return (error);
  270         error = dofileread(td, fd, fp, auio, (off_t)-1, 0);
  271         fdrop(fp, td);
  272         return (error);
  273 }
  274 
  275 /*
  276  * Scatter positioned read system call.
  277  */
  278 #ifndef _SYS_SYSPROTO_H_
  279 struct preadv_args {
  280         int     fd;
  281         struct  iovec *iovp;
  282         u_int   iovcnt;
  283         off_t   offset;
  284 };
  285 #endif
  286 int
  287 sys_preadv(struct thread *td, struct preadv_args *uap)
  288 {
  289         struct uio *auio;
  290         int error;
  291 
  292         error = copyinuio(uap->iovp, uap->iovcnt, &auio);
  293         if (error)
  294                 return (error);
  295         error = kern_preadv(td, uap->fd, auio, uap->offset);
  296         free(auio, M_IOV);
  297         return (error);
  298 }
  299 
  300 int
  301 kern_preadv(td, fd, auio, offset)
  302         struct thread *td;
  303         int fd;
  304         struct uio *auio;
  305         off_t offset;
  306 {
  307         struct file *fp;
  308         cap_rights_t rights;
  309         int error;
  310 
  311         error = fget_read(td, fd, cap_rights_init(&rights, CAP_PREAD), &fp);
  312         if (error)
  313                 return (error);
  314         if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
  315                 error = ESPIPE;
  316         else if (offset < 0 && fp->f_vnode->v_type != VCHR)
  317                 error = EINVAL;
  318         else
  319                 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET);
  320         fdrop(fp, td);
  321         return (error);
  322 }
  323 
  324 /*
  325  * Common code for readv and preadv that reads data in
  326  * from a file using the passed in uio, offset, and flags.
  327  */
  328 static int
  329 dofileread(td, fd, fp, auio, offset, flags)
  330         struct thread *td;
  331         int fd;
  332         struct file *fp;
  333         struct uio *auio;
  334         off_t offset;
  335         int flags;
  336 {
  337         ssize_t cnt;
  338         int error;
  339 #ifdef KTRACE
  340         struct uio *ktruio = NULL;
  341 #endif
  342 
  343         /* Finish zero length reads right here */
  344         if (auio->uio_resid == 0) {
  345                 td->td_retval[0] = 0;
  346                 return(0);
  347         }
  348         auio->uio_rw = UIO_READ;
  349         auio->uio_offset = offset;
  350         auio->uio_td = td;
  351 #ifdef KTRACE
  352         if (KTRPOINT(td, KTR_GENIO)) 
  353                 ktruio = cloneuio(auio);
  354 #endif
  355         cnt = auio->uio_resid;
  356         if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) {
  357                 if (auio->uio_resid != cnt && (error == ERESTART ||
  358                     error == EINTR || error == EWOULDBLOCK))
  359                         error = 0;
  360         }
  361         cnt -= auio->uio_resid;
  362 #ifdef KTRACE
  363         if (ktruio != NULL) {
  364                 ktruio->uio_resid = cnt;
  365                 ktrgenio(fd, UIO_READ, ktruio, error);
  366         }
  367 #endif
  368         td->td_retval[0] = cnt;
  369         return (error);
  370 }
  371 
  372 #ifndef _SYS_SYSPROTO_H_
  373 struct write_args {
  374         int     fd;
  375         const void *buf;
  376         size_t  nbyte;
  377 };
  378 #endif
  379 int
  380 sys_write(td, uap)
  381         struct thread *td;
  382         struct write_args *uap;
  383 {
  384         struct uio auio;
  385         struct iovec aiov;
  386         int error;
  387 
  388         if (uap->nbyte > IOSIZE_MAX)
  389                 return (EINVAL);
  390         aiov.iov_base = (void *)(uintptr_t)uap->buf;
  391         aiov.iov_len = uap->nbyte;
  392         auio.uio_iov = &aiov;
  393         auio.uio_iovcnt = 1;
  394         auio.uio_resid = uap->nbyte;
  395         auio.uio_segflg = UIO_USERSPACE;
  396         error = kern_writev(td, uap->fd, &auio);
  397         return(error);
  398 }
  399 
  400 /*
  401  * Positioned write system call.
  402  */
  403 #ifndef _SYS_SYSPROTO_H_
  404 struct pwrite_args {
  405         int     fd;
  406         const void *buf;
  407         size_t  nbyte;
  408         int     pad;
  409         off_t   offset;
  410 };
  411 #endif
  412 int
  413 sys_pwrite(td, uap)
  414         struct thread *td;
  415         struct pwrite_args *uap;
  416 {
  417         struct uio auio;
  418         struct iovec aiov;
  419         int error;
  420 
  421         if (uap->nbyte > IOSIZE_MAX)
  422                 return (EINVAL);
  423         aiov.iov_base = (void *)(uintptr_t)uap->buf;
  424         aiov.iov_len = uap->nbyte;
  425         auio.uio_iov = &aiov;
  426         auio.uio_iovcnt = 1;
  427         auio.uio_resid = uap->nbyte;
  428         auio.uio_segflg = UIO_USERSPACE;
  429         error = kern_pwritev(td, uap->fd, &auio, uap->offset);
  430         return(error);
  431 }
  432 
  433 int
  434 freebsd6_pwrite(td, uap)
  435         struct thread *td;
  436         struct freebsd6_pwrite_args *uap;
  437 {
  438         struct pwrite_args oargs;
  439 
  440         oargs.fd = uap->fd;
  441         oargs.buf = uap->buf;
  442         oargs.nbyte = uap->nbyte;
  443         oargs.offset = uap->offset;
  444         return (sys_pwrite(td, &oargs));
  445 }
  446 
  447 /*
  448  * Gather write system call.
  449  */
  450 #ifndef _SYS_SYSPROTO_H_
  451 struct writev_args {
  452         int     fd;
  453         struct  iovec *iovp;
  454         u_int   iovcnt;
  455 };
  456 #endif
  457 int
  458 sys_writev(struct thread *td, struct writev_args *uap)
  459 {
  460         struct uio *auio;
  461         int error;
  462 
  463         error = copyinuio(uap->iovp, uap->iovcnt, &auio);
  464         if (error)
  465                 return (error);
  466         error = kern_writev(td, uap->fd, auio);
  467         free(auio, M_IOV);
  468         return (error);
  469 }
  470 
  471 int
  472 kern_writev(struct thread *td, int fd, struct uio *auio)
  473 {
  474         struct file *fp;
  475         cap_rights_t rights;
  476         int error;
  477 
  478         error = fget_write(td, fd, cap_rights_init(&rights, CAP_WRITE), &fp);
  479         if (error)
  480                 return (error);
  481         error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0);
  482         fdrop(fp, td);
  483         return (error);
  484 }
  485 
  486 /*
  487  * Gather positioned write system call.
  488  */
  489 #ifndef _SYS_SYSPROTO_H_
  490 struct pwritev_args {
  491         int     fd;
  492         struct  iovec *iovp;
  493         u_int   iovcnt;
  494         off_t   offset;
  495 };
  496 #endif
  497 int
  498 sys_pwritev(struct thread *td, struct pwritev_args *uap)
  499 {
  500         struct uio *auio;
  501         int error;
  502 
  503         error = copyinuio(uap->iovp, uap->iovcnt, &auio);
  504         if (error)
  505                 return (error);
  506         error = kern_pwritev(td, uap->fd, auio, uap->offset);
  507         free(auio, M_IOV);
  508         return (error);
  509 }
  510 
  511 int
  512 kern_pwritev(td, fd, auio, offset)
  513         struct thread *td;
  514         struct uio *auio;
  515         int fd;
  516         off_t offset;
  517 {
  518         struct file *fp;
  519         cap_rights_t rights;
  520         int error;
  521 
  522         error = fget_write(td, fd, cap_rights_init(&rights, CAP_PWRITE), &fp);
  523         if (error)
  524                 return (error);
  525         if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
  526                 error = ESPIPE;
  527         else if (offset < 0 && fp->f_vnode->v_type != VCHR)
  528                 error = EINVAL;
  529         else
  530                 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET);
  531         fdrop(fp, td);
  532         return (error);
  533 }
  534 
  535 /*
  536  * Common code for writev and pwritev that writes data to
  537  * a file using the passed in uio, offset, and flags.
  538  */
  539 static int
  540 dofilewrite(td, fd, fp, auio, offset, flags)
  541         struct thread *td;
  542         int fd;
  543         struct file *fp;
  544         struct uio *auio;
  545         off_t offset;
  546         int flags;
  547 {
  548         ssize_t cnt;
  549         int error;
  550 #ifdef KTRACE
  551         struct uio *ktruio = NULL;
  552 #endif
  553 
  554         auio->uio_rw = UIO_WRITE;
  555         auio->uio_td = td;
  556         auio->uio_offset = offset;
  557 #ifdef KTRACE
  558         if (KTRPOINT(td, KTR_GENIO))
  559                 ktruio = cloneuio(auio);
  560 #endif
  561         cnt = auio->uio_resid;
  562         if (fp->f_type == DTYPE_VNODE &&
  563             (fp->f_vnread_flags & FDEVFS_VNODE) == 0)
  564                 bwillwrite();
  565         if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) {
  566                 if (auio->uio_resid != cnt && (error == ERESTART ||
  567                     error == EINTR || error == EWOULDBLOCK))
  568                         error = 0;
  569                 /* Socket layer is responsible for issuing SIGPIPE. */
  570                 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) {
  571                         PROC_LOCK(td->td_proc);
  572                         tdsignal(td, SIGPIPE);
  573                         PROC_UNLOCK(td->td_proc);
  574                 }
  575         }
  576         cnt -= auio->uio_resid;
  577 #ifdef KTRACE
  578         if (ktruio != NULL) {
  579                 ktruio->uio_resid = cnt;
  580                 ktrgenio(fd, UIO_WRITE, ktruio, error);
  581         }
  582 #endif
  583         td->td_retval[0] = cnt;
  584         return (error);
  585 }
  586 
  587 /*
  588  * Truncate a file given a file descriptor.
  589  *
  590  * Can't use fget_write() here, since must return EINVAL and not EBADF if the
  591  * descriptor isn't writable.
  592  */
  593 int
  594 kern_ftruncate(td, fd, length)
  595         struct thread *td;
  596         int fd;
  597         off_t length;
  598 {
  599         struct file *fp;
  600         cap_rights_t rights;
  601         int error;
  602 
  603         AUDIT_ARG_FD(fd);
  604         if (length < 0)
  605                 return (EINVAL);
  606         error = fget(td, fd, cap_rights_init(&rights, CAP_FTRUNCATE), &fp);
  607         if (error)
  608                 return (error);
  609         AUDIT_ARG_FILE(td->td_proc, fp);
  610         if (!(fp->f_flag & FWRITE)) {
  611                 fdrop(fp, td);
  612                 return (EINVAL);
  613         }
  614         error = fo_truncate(fp, length, td->td_ucred, td);
  615         fdrop(fp, td);
  616         return (error);
  617 }
  618 
  619 #ifndef _SYS_SYSPROTO_H_
  620 struct ftruncate_args {
  621         int     fd;
  622         int     pad;
  623         off_t   length;
  624 };
  625 #endif
  626 int
  627 sys_ftruncate(td, uap)
  628         struct thread *td;
  629         struct ftruncate_args *uap;
  630 {
  631 
  632         return (kern_ftruncate(td, uap->fd, uap->length));
  633 }
  634 
  635 #if defined(COMPAT_43)
  636 #ifndef _SYS_SYSPROTO_H_
  637 struct oftruncate_args {
  638         int     fd;
  639         long    length;
  640 };
  641 #endif
  642 int
  643 oftruncate(td, uap)
  644         struct thread *td;
  645         struct oftruncate_args *uap;
  646 {
  647 
  648         return (kern_ftruncate(td, uap->fd, uap->length));
  649 }
  650 #endif /* COMPAT_43 */
  651 
  652 #ifndef _SYS_SYSPROTO_H_
  653 struct ioctl_args {
  654         int     fd;
  655         u_long  com;
  656         caddr_t data;
  657 };
  658 #endif
  659 /* ARGSUSED */
  660 int
  661 sys_ioctl(struct thread *td, struct ioctl_args *uap)
  662 {
  663         u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN);
  664         u_long com;
  665         int arg, error;
  666         u_int size;
  667         caddr_t data;
  668 
  669         if (uap->com > 0xffffffff) {
  670                 printf(
  671                     "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n",
  672                     td->td_proc->p_pid, td->td_name, uap->com);
  673                 uap->com &= 0xffffffff;
  674         }
  675         com = uap->com;
  676 
  677         /*
  678          * Interpret high order word to find amount of data to be
  679          * copied to/from the user's address space.
  680          */
  681         size = IOCPARM_LEN(com);
  682         if ((size > IOCPARM_MAX) ||
  683             ((com & (IOC_VOID  | IOC_IN | IOC_OUT)) == 0) ||
  684 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
  685             ((com & IOC_OUT) && size == 0) ||
  686 #else
  687             ((com & (IOC_IN | IOC_OUT)) && size == 0) ||
  688 #endif
  689             ((com & IOC_VOID) && size > 0 && size != sizeof(int)))
  690                 return (ENOTTY);
  691 
  692         if (size > 0) {
  693                 if (com & IOC_VOID) {
  694                         /* Integer argument. */
  695                         arg = (intptr_t)uap->data;
  696                         data = (void *)&arg;
  697                         size = 0;
  698                 } else {
  699                         if (size > SYS_IOCTL_SMALL_SIZE)
  700                                 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
  701                         else
  702                                 data = smalldata;
  703                 }
  704         } else
  705                 data = (void *)&uap->data;
  706         if (com & IOC_IN) {
  707                 error = copyin(uap->data, data, (u_int)size);
  708                 if (error != 0)
  709                         goto out;
  710         } else if (com & IOC_OUT) {
  711                 /*
  712                  * Zero the buffer so the user always
  713                  * gets back something deterministic.
  714                  */
  715                 bzero(data, size);
  716         }
  717 
  718         error = kern_ioctl(td, uap->fd, com, data);
  719 
  720         if (error == 0 && (com & IOC_OUT))
  721                 error = copyout(data, uap->data, (u_int)size);
  722 
  723 out:
  724         if (size > SYS_IOCTL_SMALL_SIZE)
  725                 free(data, M_IOCTLOPS);
  726         return (error);
  727 }
  728 
  729 int
  730 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data)
  731 {
  732         struct file *fp;
  733         struct filedesc *fdp;
  734 #ifndef CAPABILITIES
  735         cap_rights_t rights;
  736 #endif
  737         int error, tmp, locked;
  738 
  739         AUDIT_ARG_FD(fd);
  740         AUDIT_ARG_CMD(com);
  741 
  742         fdp = td->td_proc->p_fd;
  743 
  744         switch (com) {
  745         case FIONCLEX:
  746         case FIOCLEX:
  747                 FILEDESC_XLOCK(fdp);
  748                 locked = LA_XLOCKED;
  749                 break;
  750         default:
  751 #ifdef CAPABILITIES
  752                 FILEDESC_SLOCK(fdp);
  753                 locked = LA_SLOCKED;
  754 #else
  755                 locked = LA_UNLOCKED;
  756 #endif
  757                 break;
  758         }
  759 
  760 #ifdef CAPABILITIES
  761         if ((fp = fget_locked(fdp, fd)) == NULL) {
  762                 error = EBADF;
  763                 goto out;
  764         }
  765         if ((error = cap_ioctl_check(fdp, fd, com)) != 0) {
  766                 fp = NULL;      /* fhold() was not called yet */
  767                 goto out;
  768         }
  769         fhold(fp);
  770         if (locked == LA_SLOCKED) {
  771                 FILEDESC_SUNLOCK(fdp);
  772                 locked = LA_UNLOCKED;
  773         }
  774 #else
  775         error = fget(td, fd, cap_rights_init(&rights, CAP_IOCTL), &fp);
  776         if (error != 0) {
  777                 fp = NULL;
  778                 goto out;
  779         }
  780 #endif
  781         if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
  782                 error = EBADF;
  783                 goto out;
  784         }
  785 
  786         switch (com) {
  787         case FIONCLEX:
  788                 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE;
  789                 goto out;
  790         case FIOCLEX:
  791                 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE;
  792                 goto out;
  793         case FIONBIO:
  794                 if ((tmp = *(int *)data))
  795                         atomic_set_int(&fp->f_flag, FNONBLOCK);
  796                 else
  797                         atomic_clear_int(&fp->f_flag, FNONBLOCK);
  798                 data = (void *)&tmp;
  799                 break;
  800         case FIOASYNC:
  801                 if ((tmp = *(int *)data))
  802                         atomic_set_int(&fp->f_flag, FASYNC);
  803                 else
  804                         atomic_clear_int(&fp->f_flag, FASYNC);
  805                 data = (void *)&tmp;
  806                 break;
  807         }
  808 
  809         error = fo_ioctl(fp, com, data, td->td_ucred, td);
  810 out:
  811         switch (locked) {
  812         case LA_XLOCKED:
  813                 FILEDESC_XUNLOCK(fdp);
  814                 break;
  815 #ifdef CAPABILITIES
  816         case LA_SLOCKED:
  817                 FILEDESC_SUNLOCK(fdp);
  818                 break;
  819 #endif
  820         default:
  821                 FILEDESC_UNLOCK_ASSERT(fdp);
  822                 break;
  823         }
  824         if (fp != NULL)
  825                 fdrop(fp, td);
  826         return (error);
  827 }
  828 
  829 int
  830 poll_no_poll(int events)
  831 {
  832         /*
  833          * Return true for read/write.  If the user asked for something
  834          * special, return POLLNVAL, so that clients have a way of
  835          * determining reliably whether or not the extended
  836          * functionality is present without hard-coding knowledge
  837          * of specific filesystem implementations.
  838          */
  839         if (events & ~POLLSTANDARD)
  840                 return (POLLNVAL);
  841 
  842         return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
  843 }
  844 
  845 int
  846 sys_pselect(struct thread *td, struct pselect_args *uap)
  847 {
  848         struct timespec ts;
  849         struct timeval tv, *tvp;
  850         sigset_t set, *uset;
  851         int error;
  852 
  853         if (uap->ts != NULL) {
  854                 error = copyin(uap->ts, &ts, sizeof(ts));
  855                 if (error != 0)
  856                     return (error);
  857                 TIMESPEC_TO_TIMEVAL(&tv, &ts);
  858                 tvp = &tv;
  859         } else
  860                 tvp = NULL;
  861         if (uap->sm != NULL) {
  862                 error = copyin(uap->sm, &set, sizeof(set));
  863                 if (error != 0)
  864                         return (error);
  865                 uset = &set;
  866         } else
  867                 uset = NULL;
  868         return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
  869             uset, NFDBITS));
  870 }
  871 
  872 int
  873 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex,
  874     struct timeval *tvp, sigset_t *uset, int abi_nfdbits)
  875 {
  876         int error;
  877 
  878         if (uset != NULL) {
  879                 error = kern_sigprocmask(td, SIG_SETMASK, uset,
  880                     &td->td_oldsigmask, 0);
  881                 if (error != 0)
  882                         return (error);
  883                 td->td_pflags |= TDP_OLDMASK;
  884                 /*
  885                  * Make sure that ast() is called on return to
  886                  * usermode and TDP_OLDMASK is cleared, restoring old
  887                  * sigmask.
  888                  */
  889                 thread_lock(td);
  890                 td->td_flags |= TDF_ASTPENDING;
  891                 thread_unlock(td);
  892         }
  893         error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits);
  894         return (error);
  895 }
  896 
  897 #ifndef _SYS_SYSPROTO_H_
  898 struct select_args {
  899         int     nd;
  900         fd_set  *in, *ou, *ex;
  901         struct  timeval *tv;
  902 };
  903 #endif
  904 int
  905 sys_select(struct thread *td, struct select_args *uap)
  906 {
  907         struct timeval tv, *tvp;
  908         int error;
  909 
  910         if (uap->tv != NULL) {
  911                 error = copyin(uap->tv, &tv, sizeof(tv));
  912                 if (error)
  913                         return (error);
  914                 tvp = &tv;
  915         } else
  916                 tvp = NULL;
  917 
  918         return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
  919             NFDBITS));
  920 }
  921 
  922 /*
  923  * In the unlikely case when user specified n greater then the last
  924  * open file descriptor, check that no bits are set after the last
  925  * valid fd.  We must return EBADF if any is set.
  926  *
  927  * There are applications that rely on the behaviour.
  928  *
  929  * nd is fd_lastfile + 1.
  930  */
  931 static int
  932 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits)
  933 {
  934         char *addr, *oaddr;
  935         int b, i, res;
  936         uint8_t bits;
  937 
  938         if (nd >= ndu || fd_in == NULL)
  939                 return (0);
  940 
  941         oaddr = NULL;
  942         bits = 0; /* silence gcc */
  943         for (i = nd; i < ndu; i++) {
  944                 b = i / NBBY;
  945 #if BYTE_ORDER == LITTLE_ENDIAN
  946                 addr = (char *)fd_in + b;
  947 #else
  948                 addr = (char *)fd_in;
  949                 if (abi_nfdbits == NFDBITS) {
  950                         addr += rounddown(b, sizeof(fd_mask)) +
  951                             sizeof(fd_mask) - 1 - b % sizeof(fd_mask);
  952                 } else {
  953                         addr += rounddown(b, sizeof(uint32_t)) +
  954                             sizeof(uint32_t) - 1 - b % sizeof(uint32_t);
  955                 }
  956 #endif
  957                 if (addr != oaddr) {
  958                         res = fubyte(addr);
  959                         if (res == -1)
  960                                 return (EFAULT);
  961                         oaddr = addr;
  962                         bits = res;
  963                 }
  964                 if ((bits & (1 << (i % NBBY))) != 0)
  965                         return (EBADF);
  966         }
  967         return (0);
  968 }
  969 
  970 int
  971 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou,
  972     fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits)
  973 {
  974         struct filedesc *fdp;
  975         /*
  976          * The magic 2048 here is chosen to be just enough for FD_SETSIZE
  977          * infds with the new FD_SETSIZE of 1024, and more than enough for
  978          * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE
  979          * of 256.
  980          */
  981         fd_mask s_selbits[howmany(2048, NFDBITS)];
  982         fd_mask *ibits[3], *obits[3], *selbits, *sbp;
  983         struct timeval rtv;
  984         sbintime_t asbt, precision, rsbt;
  985         u_int nbufbytes, ncpbytes, ncpubytes, nfdbits;
  986         int error, lf, ndu;
  987 
  988         if (nd < 0)
  989                 return (EINVAL);
  990         fdp = td->td_proc->p_fd;
  991         ndu = nd;
  992         lf = fdp->fd_lastfile;
  993         if (nd > lf + 1)
  994                 nd = lf + 1;
  995 
  996         error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits);
  997         if (error != 0)
  998                 return (error);
  999         error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits);
 1000         if (error != 0)
 1001                 return (error);
 1002         error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits);
 1003         if (error != 0)
 1004                 return (error);
 1005 
 1006         /*
 1007          * Allocate just enough bits for the non-null fd_sets.  Use the
 1008          * preallocated auto buffer if possible.
 1009          */
 1010         nfdbits = roundup(nd, NFDBITS);
 1011         ncpbytes = nfdbits / NBBY;
 1012         ncpubytes = roundup(nd, abi_nfdbits) / NBBY;
 1013         nbufbytes = 0;
 1014         if (fd_in != NULL)
 1015                 nbufbytes += 2 * ncpbytes;
 1016         if (fd_ou != NULL)
 1017                 nbufbytes += 2 * ncpbytes;
 1018         if (fd_ex != NULL)
 1019                 nbufbytes += 2 * ncpbytes;
 1020         if (nbufbytes <= sizeof s_selbits)
 1021                 selbits = &s_selbits[0];
 1022         else
 1023                 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK);
 1024 
 1025         /*
 1026          * Assign pointers into the bit buffers and fetch the input bits.
 1027          * Put the output buffers together so that they can be bzeroed
 1028          * together.
 1029          */
 1030         sbp = selbits;
 1031 #define getbits(name, x) \
 1032         do {                                                            \
 1033                 if (name == NULL) {                                     \
 1034                         ibits[x] = NULL;                                \
 1035                         obits[x] = NULL;                                \
 1036                 } else {                                                \
 1037                         ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp;   \
 1038                         obits[x] = sbp;                                 \
 1039                         sbp += ncpbytes / sizeof *sbp;                  \
 1040                         error = copyin(name, ibits[x], ncpubytes);      \
 1041                         if (error != 0)                                 \
 1042                                 goto done;                              \
 1043                         bzero((char *)ibits[x] + ncpubytes,             \
 1044                             ncpbytes - ncpubytes);                      \
 1045                 }                                                       \
 1046         } while (0)
 1047         getbits(fd_in, 0);
 1048         getbits(fd_ou, 1);
 1049         getbits(fd_ex, 2);
 1050 #undef  getbits
 1051 
 1052 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__)
 1053         /*
 1054          * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS,
 1055          * we are running under 32-bit emulation. This should be more
 1056          * generic.
 1057          */
 1058 #define swizzle_fdset(bits)                                             \
 1059         if (abi_nfdbits != NFDBITS && bits != NULL) {                   \
 1060                 int i;                                                  \
 1061                 for (i = 0; i < ncpbytes / sizeof *sbp; i++)            \
 1062                         bits[i] = (bits[i] >> 32) | (bits[i] << 32);    \
 1063         }
 1064 #else
 1065 #define swizzle_fdset(bits)
 1066 #endif
 1067 
 1068         /* Make sure the bit order makes it through an ABI transition */
 1069         swizzle_fdset(ibits[0]);
 1070         swizzle_fdset(ibits[1]);
 1071         swizzle_fdset(ibits[2]);
 1072         
 1073         if (nbufbytes != 0)
 1074                 bzero(selbits, nbufbytes / 2);
 1075 
 1076         precision = 0;
 1077         if (tvp != NULL) {
 1078                 rtv = *tvp;
 1079                 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 ||
 1080                     rtv.tv_usec >= 1000000) {
 1081                         error = EINVAL;
 1082                         goto done;
 1083                 }
 1084                 if (!timevalisset(&rtv))
 1085                         asbt = 0;
 1086                 else if (rtv.tv_sec <= INT32_MAX) {
 1087                         rsbt = tvtosbt(rtv);
 1088                         precision = rsbt;
 1089                         precision >>= tc_precexp;
 1090                         if (TIMESEL(&asbt, rsbt))
 1091                                 asbt += tc_tick_sbt;
 1092                         if (asbt <= INT64_MAX - rsbt)
 1093                                 asbt += rsbt;
 1094                         else
 1095                                 asbt = -1;
 1096                 } else
 1097                         asbt = -1;
 1098         } else
 1099                 asbt = -1;
 1100         seltdinit(td);
 1101         /* Iterate until the timeout expires or descriptors become ready. */
 1102         for (;;) {
 1103                 error = selscan(td, ibits, obits, nd);
 1104                 if (error || td->td_retval[0] != 0)
 1105                         break;
 1106                 error = seltdwait(td, asbt, precision);
 1107                 if (error)
 1108                         break;
 1109                 error = selrescan(td, ibits, obits);
 1110                 if (error || td->td_retval[0] != 0)
 1111                         break;
 1112         }
 1113         seltdclear(td);
 1114 
 1115 done:
 1116         /* select is not restarted after signals... */
 1117         if (error == ERESTART)
 1118                 error = EINTR;
 1119         if (error == EWOULDBLOCK)
 1120                 error = 0;
 1121 
 1122         /* swizzle bit order back, if necessary */
 1123         swizzle_fdset(obits[0]);
 1124         swizzle_fdset(obits[1]);
 1125         swizzle_fdset(obits[2]);
 1126 #undef swizzle_fdset
 1127 
 1128 #define putbits(name, x) \
 1129         if (name && (error2 = copyout(obits[x], name, ncpubytes))) \
 1130                 error = error2;
 1131         if (error == 0) {
 1132                 int error2;
 1133 
 1134                 putbits(fd_in, 0);
 1135                 putbits(fd_ou, 1);
 1136                 putbits(fd_ex, 2);
 1137 #undef putbits
 1138         }
 1139         if (selbits != &s_selbits[0])
 1140                 free(selbits, M_SELECT);
 1141 
 1142         return (error);
 1143 }
 1144 /* 
 1145  * Convert a select bit set to poll flags.
 1146  *
 1147  * The backend always returns POLLHUP/POLLERR if appropriate and we
 1148  * return this as a set bit in any set.
 1149  */
 1150 static int select_flags[3] = {
 1151     POLLRDNORM | POLLHUP | POLLERR,
 1152     POLLWRNORM | POLLHUP | POLLERR,
 1153     POLLRDBAND | POLLERR
 1154 };
 1155 
 1156 /*
 1157  * Compute the fo_poll flags required for a fd given by the index and
 1158  * bit position in the fd_mask array.
 1159  */
 1160 static __inline int
 1161 selflags(fd_mask **ibits, int idx, fd_mask bit)
 1162 {
 1163         int flags;
 1164         int msk;
 1165 
 1166         flags = 0;
 1167         for (msk = 0; msk < 3; msk++) {
 1168                 if (ibits[msk] == NULL)
 1169                         continue;
 1170                 if ((ibits[msk][idx] & bit) == 0)
 1171                         continue;
 1172                 flags |= select_flags[msk];
 1173         }
 1174         return (flags);
 1175 }
 1176 
 1177 /*
 1178  * Set the appropriate output bits given a mask of fired events and the
 1179  * input bits originally requested.
 1180  */
 1181 static __inline int
 1182 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events)
 1183 {
 1184         int msk;
 1185         int n;
 1186 
 1187         n = 0;
 1188         for (msk = 0; msk < 3; msk++) {
 1189                 if ((events & select_flags[msk]) == 0)
 1190                         continue;
 1191                 if (ibits[msk] == NULL)
 1192                         continue;
 1193                 if ((ibits[msk][idx] & bit) == 0)
 1194                         continue;
 1195                 /*
 1196                  * XXX Check for a duplicate set.  This can occur because a
 1197                  * socket calls selrecord() twice for each poll() call
 1198                  * resulting in two selfds per real fd.  selrescan() will
 1199                  * call selsetbits twice as a result.
 1200                  */
 1201                 if ((obits[msk][idx] & bit) != 0)
 1202                         continue;
 1203                 obits[msk][idx] |= bit;
 1204                 n++;
 1205         }
 1206 
 1207         return (n);
 1208 }
 1209 
 1210 static __inline int
 1211 getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp)
 1212 {
 1213         cap_rights_t rights;
 1214 
 1215         cap_rights_init(&rights, CAP_EVENT);
 1216 
 1217         return (fget_unlocked(fdp, fd, &rights, 0, fpp, NULL));
 1218 }
 1219 
 1220 /*
 1221  * Traverse the list of fds attached to this thread's seltd and check for
 1222  * completion.
 1223  */
 1224 static int
 1225 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits)
 1226 {
 1227         struct filedesc *fdp;
 1228         struct selinfo *si;
 1229         struct seltd *stp;
 1230         struct selfd *sfp;
 1231         struct selfd *sfn;
 1232         struct file *fp;
 1233         fd_mask bit;
 1234         int fd, ev, n, idx;
 1235         int error;
 1236 
 1237         fdp = td->td_proc->p_fd;
 1238         stp = td->td_sel;
 1239         n = 0;
 1240         STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
 1241                 fd = (int)(uintptr_t)sfp->sf_cookie;
 1242                 si = sfp->sf_si;
 1243                 selfdfree(stp, sfp);
 1244                 /* If the selinfo wasn't cleared the event didn't fire. */
 1245                 if (si != NULL)
 1246                         continue;
 1247                 error = getselfd_cap(fdp, fd, &fp);
 1248                 if (error)
 1249                         return (error);
 1250                 idx = fd / NFDBITS;
 1251                 bit = (fd_mask)1 << (fd % NFDBITS);
 1252                 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td);
 1253                 fdrop(fp, td);
 1254                 if (ev != 0)
 1255                         n += selsetbits(ibits, obits, idx, bit, ev);
 1256         }
 1257         stp->st_flags = 0;
 1258         td->td_retval[0] = n;
 1259         return (0);
 1260 }
 1261 
 1262 /*
 1263  * Perform the initial filedescriptor scan and register ourselves with
 1264  * each selinfo.
 1265  */
 1266 static int
 1267 selscan(td, ibits, obits, nfd)
 1268         struct thread *td;
 1269         fd_mask **ibits, **obits;
 1270         int nfd;
 1271 {
 1272         struct filedesc *fdp;
 1273         struct file *fp;
 1274         fd_mask bit;
 1275         int ev, flags, end, fd;
 1276         int n, idx;
 1277         int error;
 1278 
 1279         fdp = td->td_proc->p_fd;
 1280         n = 0;
 1281         for (idx = 0, fd = 0; fd < nfd; idx++) {
 1282                 end = imin(fd + NFDBITS, nfd);
 1283                 for (bit = 1; fd < end; bit <<= 1, fd++) {
 1284                         /* Compute the list of events we're interested in. */
 1285                         flags = selflags(ibits, idx, bit);
 1286                         if (flags == 0)
 1287                                 continue;
 1288                         error = getselfd_cap(fdp, fd, &fp);
 1289                         if (error)
 1290                                 return (error);
 1291                         selfdalloc(td, (void *)(uintptr_t)fd);
 1292                         ev = fo_poll(fp, flags, td->td_ucred, td);
 1293                         fdrop(fp, td);
 1294                         if (ev != 0)
 1295                                 n += selsetbits(ibits, obits, idx, bit, ev);
 1296                 }
 1297         }
 1298 
 1299         td->td_retval[0] = n;
 1300         return (0);
 1301 }
 1302 
 1303 int
 1304 sys_poll(struct thread *td, struct poll_args *uap)
 1305 {
 1306         struct timespec ts, *tsp;
 1307 
 1308         if (uap->timeout != INFTIM) {
 1309                 if (uap->timeout < 0)
 1310                         return (EINVAL);
 1311                 ts.tv_sec = uap->timeout / 1000;
 1312                 ts.tv_nsec = (uap->timeout % 1000) * 1000000;
 1313                 tsp = &ts;
 1314         } else
 1315                 tsp = NULL;
 1316 
 1317         return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL));
 1318 }
 1319 
 1320 int
 1321 kern_poll(struct thread *td, struct pollfd *fds, u_int nfds,
 1322     struct timespec *tsp, sigset_t *uset)
 1323 {
 1324         struct pollfd *bits;
 1325         struct pollfd smallbits[32];
 1326         sbintime_t sbt, precision, tmp;
 1327         time_t over;
 1328         struct timespec ts;
 1329         int error;
 1330         size_t ni;
 1331 
 1332         precision = 0;
 1333         if (tsp != NULL) {
 1334                 if (tsp->tv_sec < 0)
 1335                         return (EINVAL);
 1336                 if (tsp->tv_nsec < 0 || tsp->tv_nsec >= 1000000000)
 1337                         return (EINVAL);
 1338                 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
 1339                         sbt = 0;
 1340                 else {
 1341                         ts = *tsp;
 1342                         if (ts.tv_sec > INT32_MAX / 2) {
 1343                                 over = ts.tv_sec - INT32_MAX / 2;
 1344                                 ts.tv_sec -= over;
 1345                         } else
 1346                                 over = 0;
 1347                         tmp = tstosbt(ts);
 1348                         precision = tmp;
 1349                         precision >>= tc_precexp;
 1350                         if (TIMESEL(&sbt, tmp))
 1351                                 sbt += tc_tick_sbt;
 1352                         sbt += tmp;
 1353                 }
 1354         } else
 1355                 sbt = -1;
 1356 
 1357         if (nfds > maxfilesperproc && nfds > FD_SETSIZE) 
 1358                 return (EINVAL);
 1359         ni = nfds * sizeof(struct pollfd);
 1360         if (ni > sizeof(smallbits))
 1361                 bits = malloc(ni, M_TEMP, M_WAITOK);
 1362         else
 1363                 bits = smallbits;
 1364         error = copyin(fds, bits, ni);
 1365         if (error)
 1366                 goto done;
 1367 
 1368         if (uset != NULL) {
 1369                 error = kern_sigprocmask(td, SIG_SETMASK, uset,
 1370                     &td->td_oldsigmask, 0);
 1371                 if (error)
 1372                         goto done;
 1373                 td->td_pflags |= TDP_OLDMASK;
 1374                 /*
 1375                  * Make sure that ast() is called on return to
 1376                  * usermode and TDP_OLDMASK is cleared, restoring old
 1377                  * sigmask.
 1378                  */
 1379                 thread_lock(td);
 1380                 td->td_flags |= TDF_ASTPENDING;
 1381                 thread_unlock(td);
 1382         }
 1383 
 1384         seltdinit(td);
 1385         /* Iterate until the timeout expires or descriptors become ready. */
 1386         for (;;) {
 1387                 error = pollscan(td, bits, nfds);
 1388                 if (error || td->td_retval[0] != 0)
 1389                         break;
 1390                 error = seltdwait(td, sbt, precision);
 1391                 if (error)
 1392                         break;
 1393                 error = pollrescan(td);
 1394                 if (error || td->td_retval[0] != 0)
 1395                         break;
 1396         }
 1397         seltdclear(td);
 1398 
 1399 done:
 1400         /* poll is not restarted after signals... */
 1401         if (error == ERESTART)
 1402                 error = EINTR;
 1403         if (error == EWOULDBLOCK)
 1404                 error = 0;
 1405         if (error == 0) {
 1406                 error = pollout(td, bits, fds, nfds);
 1407                 if (error)
 1408                         goto out;
 1409         }
 1410 out:
 1411         if (ni > sizeof(smallbits))
 1412                 free(bits, M_TEMP);
 1413         return (error);
 1414 }
 1415 
 1416 int
 1417 sys_ppoll(struct thread *td, struct ppoll_args *uap)
 1418 {
 1419         struct timespec ts, *tsp;
 1420         sigset_t set, *ssp;
 1421         int error;
 1422 
 1423         if (uap->ts != NULL) {
 1424                 error = copyin(uap->ts, &ts, sizeof(ts));
 1425                 if (error)
 1426                         return (error);
 1427                 tsp = &ts;
 1428         } else
 1429                 tsp = NULL;
 1430         if (uap->set != NULL) {
 1431                 error = copyin(uap->set, &set, sizeof(set));
 1432                 if (error)
 1433                         return (error);
 1434                 ssp = &set;
 1435         } else
 1436                 ssp = NULL;
 1437         /*
 1438          * fds is still a pointer to user space. kern_poll() will
 1439          * take care of copyin that array to the kernel space.
 1440          */
 1441 
 1442         return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp));
 1443 }
 1444 
 1445 static int
 1446 pollrescan(struct thread *td)
 1447 {
 1448         struct seltd *stp;
 1449         struct selfd *sfp;
 1450         struct selfd *sfn;
 1451         struct selinfo *si;
 1452         struct filedesc *fdp;
 1453         struct file *fp;
 1454         struct pollfd *fd;
 1455 #ifdef CAPABILITIES
 1456         cap_rights_t rights;
 1457 #endif
 1458         int n;
 1459 
 1460         n = 0;
 1461         fdp = td->td_proc->p_fd;
 1462         stp = td->td_sel;
 1463         FILEDESC_SLOCK(fdp);
 1464         STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
 1465                 fd = (struct pollfd *)sfp->sf_cookie;
 1466                 si = sfp->sf_si;
 1467                 selfdfree(stp, sfp);
 1468                 /* If the selinfo wasn't cleared the event didn't fire. */
 1469                 if (si != NULL)
 1470                         continue;
 1471                 fp = fdp->fd_ofiles[fd->fd].fde_file;
 1472 #ifdef CAPABILITIES
 1473                 if (fp == NULL ||
 1474                     cap_check(cap_rights(fdp, fd->fd),
 1475                     cap_rights_init(&rights, CAP_EVENT)) != 0)
 1476 #else
 1477                 if (fp == NULL)
 1478 #endif
 1479                 {
 1480                         fd->revents = POLLNVAL;
 1481                         n++;
 1482                         continue;
 1483                 }
 1484 
 1485                 /*
 1486                  * Note: backend also returns POLLHUP and
 1487                  * POLLERR if appropriate.
 1488                  */
 1489                 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td);
 1490                 if (fd->revents != 0)
 1491                         n++;
 1492         }
 1493         FILEDESC_SUNLOCK(fdp);
 1494         stp->st_flags = 0;
 1495         td->td_retval[0] = n;
 1496         return (0);
 1497 }
 1498 
 1499 
 1500 static int
 1501 pollout(td, fds, ufds, nfd)
 1502         struct thread *td;
 1503         struct pollfd *fds;
 1504         struct pollfd *ufds;
 1505         u_int nfd;
 1506 {
 1507         int error = 0;
 1508         u_int i = 0;
 1509         u_int n = 0;
 1510 
 1511         for (i = 0; i < nfd; i++) {
 1512                 error = copyout(&fds->revents, &ufds->revents,
 1513                     sizeof(ufds->revents));
 1514                 if (error)
 1515                         return (error);
 1516                 if (fds->revents != 0)
 1517                         n++;
 1518                 fds++;
 1519                 ufds++;
 1520         }
 1521         td->td_retval[0] = n;
 1522         return (0);
 1523 }
 1524 
 1525 static int
 1526 pollscan(td, fds, nfd)
 1527         struct thread *td;
 1528         struct pollfd *fds;
 1529         u_int nfd;
 1530 {
 1531         struct filedesc *fdp = td->td_proc->p_fd;
 1532         struct file *fp;
 1533 #ifdef CAPABILITIES
 1534         cap_rights_t rights;
 1535 #endif
 1536         int i, n = 0;
 1537 
 1538         FILEDESC_SLOCK(fdp);
 1539         for (i = 0; i < nfd; i++, fds++) {
 1540                 if (fds->fd > fdp->fd_lastfile) {
 1541                         fds->revents = POLLNVAL;
 1542                         n++;
 1543                 } else if (fds->fd < 0) {
 1544                         fds->revents = 0;
 1545                 } else {
 1546                         fp = fdp->fd_ofiles[fds->fd].fde_file;
 1547 #ifdef CAPABILITIES
 1548                         if (fp == NULL ||
 1549                             cap_check(cap_rights(fdp, fds->fd),
 1550                             cap_rights_init(&rights, CAP_EVENT)) != 0)
 1551 #else
 1552                         if (fp == NULL)
 1553 #endif
 1554                         {
 1555                                 fds->revents = POLLNVAL;
 1556                                 n++;
 1557                         } else {
 1558                                 /*
 1559                                  * Note: backend also returns POLLHUP and
 1560                                  * POLLERR if appropriate.
 1561                                  */
 1562                                 selfdalloc(td, fds);
 1563                                 fds->revents = fo_poll(fp, fds->events,
 1564                                     td->td_ucred, td);
 1565                                 /*
 1566                                  * POSIX requires POLLOUT to be never
 1567                                  * set simultaneously with POLLHUP.
 1568                                  */
 1569                                 if ((fds->revents & POLLHUP) != 0)
 1570                                         fds->revents &= ~POLLOUT;
 1571 
 1572                                 if (fds->revents != 0)
 1573                                         n++;
 1574                         }
 1575                 }
 1576         }
 1577         FILEDESC_SUNLOCK(fdp);
 1578         td->td_retval[0] = n;
 1579         return (0);
 1580 }
 1581 
 1582 /*
 1583  * OpenBSD poll system call.
 1584  *
 1585  * XXX this isn't quite a true representation..  OpenBSD uses select ops.
 1586  */
 1587 #ifndef _SYS_SYSPROTO_H_
 1588 struct openbsd_poll_args {
 1589         struct pollfd *fds;
 1590         u_int   nfds;
 1591         int     timeout;
 1592 };
 1593 #endif
 1594 int
 1595 sys_openbsd_poll(td, uap)
 1596         register struct thread *td;
 1597         register struct openbsd_poll_args *uap;
 1598 {
 1599         return (sys_poll(td, (struct poll_args *)uap));
 1600 }
 1601 
 1602 /*
 1603  * XXX This was created specifically to support netncp and netsmb.  This
 1604  * allows the caller to specify a socket to wait for events on.  It returns
 1605  * 0 if any events matched and an error otherwise.  There is no way to
 1606  * determine which events fired.
 1607  */
 1608 int
 1609 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td)
 1610 {
 1611         struct timeval rtv;
 1612         sbintime_t asbt, precision, rsbt;
 1613         int error;
 1614 
 1615         precision = 0;  /* stupid gcc! */
 1616         if (tvp != NULL) {
 1617                 rtv = *tvp;
 1618                 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || 
 1619                     rtv.tv_usec >= 1000000)
 1620                         return (EINVAL);
 1621                 if (!timevalisset(&rtv))
 1622                         asbt = 0;
 1623                 else if (rtv.tv_sec <= INT32_MAX) {
 1624                         rsbt = tvtosbt(rtv);
 1625                         precision = rsbt;
 1626                         precision >>= tc_precexp;
 1627                         if (TIMESEL(&asbt, rsbt))
 1628                                 asbt += tc_tick_sbt;
 1629                         if (asbt <= INT64_MAX - rsbt)
 1630                                 asbt += rsbt;
 1631                         else
 1632                                 asbt = -1;
 1633                 } else
 1634                         asbt = -1;
 1635         } else
 1636                 asbt = -1;
 1637         seltdinit(td);
 1638         /*
 1639          * Iterate until the timeout expires or the socket becomes ready.
 1640          */
 1641         for (;;) {
 1642                 selfdalloc(td, NULL);
 1643                 error = sopoll(so, events, NULL, td);
 1644                 /* error here is actually the ready events. */
 1645                 if (error)
 1646                         return (0);
 1647                 error = seltdwait(td, asbt, precision);
 1648                 if (error)
 1649                         break;
 1650         }
 1651         seltdclear(td);
 1652         /* XXX Duplicates ncp/smb behavior. */
 1653         if (error == ERESTART)
 1654                 error = 0;
 1655         return (error);
 1656 }
 1657 
 1658 /*
 1659  * Preallocate two selfds associated with 'cookie'.  Some fo_poll routines
 1660  * have two select sets, one for read and another for write.
 1661  */
 1662 static void
 1663 selfdalloc(struct thread *td, void *cookie)
 1664 {
 1665         struct seltd *stp;
 1666 
 1667         stp = td->td_sel;
 1668         if (stp->st_free1 == NULL)
 1669                 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
 1670         stp->st_free1->sf_td = stp;
 1671         stp->st_free1->sf_cookie = cookie;
 1672         if (stp->st_free2 == NULL)
 1673                 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
 1674         stp->st_free2->sf_td = stp;
 1675         stp->st_free2->sf_cookie = cookie;
 1676 }
 1677 
 1678 static void
 1679 selfdfree(struct seltd *stp, struct selfd *sfp)
 1680 {
 1681         STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link);
 1682         mtx_lock(sfp->sf_mtx);
 1683         if (sfp->sf_si)
 1684                 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads);
 1685         mtx_unlock(sfp->sf_mtx);
 1686         uma_zfree(selfd_zone, sfp);
 1687 }
 1688 
 1689 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */
 1690 void
 1691 seldrain(sip)
 1692         struct selinfo *sip;
 1693 {
 1694 
 1695         /*
 1696          * This feature is already provided by doselwakeup(), thus it is
 1697          * enough to go for it.
 1698          * Eventually, the context, should take care to avoid races
 1699          * between thread calling select()/poll() and file descriptor
 1700          * detaching, but, again, the races are just the same as
 1701          * selwakeup().
 1702          */
 1703         doselwakeup(sip, -1);
 1704 }
 1705 
 1706 /*
 1707  * Record a select request.
 1708  */
 1709 void
 1710 selrecord(selector, sip)
 1711         struct thread *selector;
 1712         struct selinfo *sip;
 1713 {
 1714         struct selfd *sfp;
 1715         struct seltd *stp;
 1716         struct mtx *mtxp;
 1717 
 1718         stp = selector->td_sel;
 1719         /*
 1720          * Don't record when doing a rescan.
 1721          */
 1722         if (stp->st_flags & SELTD_RESCAN)
 1723                 return;
 1724         /*
 1725          * Grab one of the preallocated descriptors.
 1726          */
 1727         sfp = NULL;
 1728         if ((sfp = stp->st_free1) != NULL)
 1729                 stp->st_free1 = NULL;
 1730         else if ((sfp = stp->st_free2) != NULL)
 1731                 stp->st_free2 = NULL;
 1732         else
 1733                 panic("selrecord: No free selfd on selq");
 1734         mtxp = sip->si_mtx;
 1735         if (mtxp == NULL)
 1736                 mtxp = mtx_pool_find(mtxpool_select, sip);
 1737         /*
 1738          * Initialize the sfp and queue it in the thread.
 1739          */
 1740         sfp->sf_si = sip;
 1741         sfp->sf_mtx = mtxp;
 1742         STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link);
 1743         /*
 1744          * Now that we've locked the sip, check for initialization.
 1745          */
 1746         mtx_lock(mtxp);
 1747         if (sip->si_mtx == NULL) {
 1748                 sip->si_mtx = mtxp;
 1749                 TAILQ_INIT(&sip->si_tdlist);
 1750         }
 1751         /*
 1752          * Add this thread to the list of selfds listening on this selinfo.
 1753          */
 1754         TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads);
 1755         mtx_unlock(sip->si_mtx);
 1756 }
 1757 
 1758 /* Wake up a selecting thread. */
 1759 void
 1760 selwakeup(sip)
 1761         struct selinfo *sip;
 1762 {
 1763         doselwakeup(sip, -1);
 1764 }
 1765 
 1766 /* Wake up a selecting thread, and set its priority. */
 1767 void
 1768 selwakeuppri(sip, pri)
 1769         struct selinfo *sip;
 1770         int pri;
 1771 {
 1772         doselwakeup(sip, pri);
 1773 }
 1774 
 1775 /*
 1776  * Do a wakeup when a selectable event occurs.
 1777  */
 1778 static void
 1779 doselwakeup(sip, pri)
 1780         struct selinfo *sip;
 1781         int pri;
 1782 {
 1783         struct selfd *sfp;
 1784         struct selfd *sfn;
 1785         struct seltd *stp;
 1786 
 1787         /* If it's not initialized there can't be any waiters. */
 1788         if (sip->si_mtx == NULL)
 1789                 return;
 1790         /*
 1791          * Locking the selinfo locks all selfds associated with it.
 1792          */
 1793         mtx_lock(sip->si_mtx);
 1794         TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) {
 1795                 /*
 1796                  * Once we remove this sfp from the list and clear the
 1797                  * sf_si seltdclear will know to ignore this si.
 1798                  */
 1799                 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads);
 1800                 sfp->sf_si = NULL;
 1801                 stp = sfp->sf_td;
 1802                 mtx_lock(&stp->st_mtx);
 1803                 stp->st_flags |= SELTD_PENDING;
 1804                 cv_broadcastpri(&stp->st_wait, pri);
 1805                 mtx_unlock(&stp->st_mtx);
 1806         }
 1807         mtx_unlock(sip->si_mtx);
 1808 }
 1809 
 1810 static void
 1811 seltdinit(struct thread *td)
 1812 {
 1813         struct seltd *stp;
 1814 
 1815         if ((stp = td->td_sel) != NULL)
 1816                 goto out;
 1817         td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO);
 1818         mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF);
 1819         cv_init(&stp->st_wait, "select");
 1820 out:
 1821         stp->st_flags = 0;
 1822         STAILQ_INIT(&stp->st_selq);
 1823 }
 1824 
 1825 static int
 1826 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision)
 1827 {
 1828         struct seltd *stp;
 1829         int error;
 1830 
 1831         stp = td->td_sel;
 1832         /*
 1833          * An event of interest may occur while we do not hold the seltd
 1834          * locked so check the pending flag before we sleep.
 1835          */
 1836         mtx_lock(&stp->st_mtx);
 1837         /*
 1838          * Any further calls to selrecord will be a rescan.
 1839          */
 1840         stp->st_flags |= SELTD_RESCAN;
 1841         if (stp->st_flags & SELTD_PENDING) {
 1842                 mtx_unlock(&stp->st_mtx);
 1843                 return (0);
 1844         }
 1845         if (sbt == 0)
 1846                 error = EWOULDBLOCK;
 1847         else if (sbt != -1)
 1848                 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx,
 1849                     sbt, precision, C_ABSOLUTE);
 1850         else
 1851                 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx);
 1852         mtx_unlock(&stp->st_mtx);
 1853 
 1854         return (error);
 1855 }
 1856 
 1857 void
 1858 seltdfini(struct thread *td)
 1859 {
 1860         struct seltd *stp;
 1861 
 1862         stp = td->td_sel;
 1863         if (stp == NULL)
 1864                 return;
 1865         if (stp->st_free1)
 1866                 uma_zfree(selfd_zone, stp->st_free1);
 1867         if (stp->st_free2)
 1868                 uma_zfree(selfd_zone, stp->st_free2);
 1869         td->td_sel = NULL;
 1870         free(stp, M_SELECT);
 1871 }
 1872 
 1873 /*
 1874  * Remove the references to the thread from all of the objects we were
 1875  * polling.
 1876  */
 1877 static void
 1878 seltdclear(struct thread *td)
 1879 {
 1880         struct seltd *stp;
 1881         struct selfd *sfp;
 1882         struct selfd *sfn;
 1883 
 1884         stp = td->td_sel;
 1885         STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn)
 1886                 selfdfree(stp, sfp);
 1887         stp->st_flags = 0;
 1888 }
 1889 
 1890 static void selectinit(void *);
 1891 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL);
 1892 static void
 1893 selectinit(void *dummy __unused)
 1894 {
 1895 
 1896         selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL,
 1897             NULL, NULL, UMA_ALIGN_PTR, 0);
 1898         mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF);
 1899 }

Cache object: 27dc9a337916ae92111a0648ce9e56e2


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