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 /*      $NetBSD: sys_generic.c,v 1.97.2.1 2007/09/11 09:58:24 xtraeme Exp $     */
    2 
    3 /*
    4  * Copyright (c) 1982, 1986, 1989, 1993
    5  *      The Regents of the University of California.  All rights reserved.
    6  * (c) UNIX System Laboratories, Inc.
    7  * All or some portions of this file are derived from material licensed
    8  * to the University of California by American Telephone and Telegraph
    9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
   10  * the permission of UNIX System Laboratories, Inc.
   11  *
   12  * Redistribution and use in source and binary forms, with or without
   13  * modification, are permitted provided that the following conditions
   14  * are met:
   15  * 1. Redistributions of source code must retain the above copyright
   16  *    notice, this list of conditions and the following disclaimer.
   17  * 2. Redistributions in binary form must reproduce the above copyright
   18  *    notice, this list of conditions and the following disclaimer in the
   19  *    documentation and/or other materials provided with the distribution.
   20  * 3. Neither the name of the University nor the names of its contributors
   21  *    may be used to endorse or promote products derived from this software
   22  *    without specific prior written permission.
   23  *
   24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   34  * SUCH DAMAGE.
   35  *
   36  *      @(#)sys_generic.c       8.9 (Berkeley) 2/14/95
   37  */
   38 
   39 #include <sys/cdefs.h>
   40 __KERNEL_RCSID(0, "$NetBSD: sys_generic.c,v 1.97.2.1 2007/09/11 09:58:24 xtraeme Exp $");
   41 
   42 #include "opt_ktrace.h"
   43 
   44 #include <sys/param.h>
   45 #include <sys/systm.h>
   46 #include <sys/filedesc.h>
   47 #include <sys/ioctl.h>
   48 #include <sys/file.h>
   49 #include <sys/proc.h>
   50 #include <sys/socketvar.h>
   51 #include <sys/signalvar.h>
   52 #include <sys/uio.h>
   53 #include <sys/kernel.h>
   54 #include <sys/stat.h>
   55 #include <sys/malloc.h>
   56 #include <sys/poll.h>
   57 #ifdef KTRACE
   58 #include <sys/ktrace.h>
   59 #endif
   60 
   61 #include <sys/mount.h>
   62 #include <sys/sa.h>
   63 #include <sys/syscallargs.h>
   64 
   65 #include <uvm/uvm_extern.h>
   66 
   67 int selscan(struct lwp *, fd_mask *, fd_mask *, int, register_t *);
   68 int pollscan(struct lwp *, struct pollfd *, int, register_t *);
   69 
   70 
   71 /*
   72  * Read system call.
   73  */
   74 /* ARGSUSED */
   75 int
   76 sys_read(struct lwp *l, void *v, register_t *retval)
   77 {
   78         struct sys_read_args /* {
   79                 syscallarg(int)         fd;
   80                 syscallarg(void *)      buf;
   81                 syscallarg(size_t)      nbyte;
   82         } */ *uap = v;
   83         int             fd;
   84         struct file     *fp;
   85         struct proc     *p;
   86         struct filedesc *fdp;
   87 
   88         fd = SCARG(uap, fd);
   89         p = l->l_proc;
   90         fdp = p->p_fd;
   91 
   92         if ((fp = fd_getfile(fdp, fd)) == NULL)
   93                 return (EBADF);
   94 
   95         if ((fp->f_flag & FREAD) == 0) {
   96                 simple_unlock(&fp->f_slock);
   97                 return (EBADF);
   98         }
   99 
  100         FILE_USE(fp);
  101 
  102         /* dofileread() will unuse the descriptor for us */
  103         return (dofileread(l, fd, fp, SCARG(uap, buf), SCARG(uap, nbyte),
  104             &fp->f_offset, FOF_UPDATE_OFFSET, retval));
  105 }
  106 
  107 int
  108 dofileread(struct lwp *l, int fd, struct file *fp, void *buf, size_t nbyte,
  109         off_t *offset, int flags, register_t *retval)
  110 {
  111         struct iovec aiov;
  112         struct uio auio;
  113         struct proc *p;
  114         struct vmspace *vm;
  115         size_t cnt;
  116         int error;
  117 #ifdef KTRACE
  118         struct iovec    ktriov = { .iov_base = NULL, };
  119 #endif
  120         p = l->l_proc;
  121 
  122         error = proc_vmspace_getref(p, &vm);
  123         if (error) {
  124                 FILE_UNUSE(fp, l);
  125                 return error;
  126         }
  127 
  128         aiov.iov_base = (caddr_t)buf;
  129         aiov.iov_len = nbyte;
  130         auio.uio_iov = &aiov;
  131         auio.uio_iovcnt = 1;
  132         auio.uio_resid = nbyte;
  133         auio.uio_rw = UIO_READ;
  134         auio.uio_vmspace = vm;
  135 
  136         /*
  137          * Reads return ssize_t because -1 is returned on error.  Therefore
  138          * we must restrict the length to SSIZE_MAX to avoid garbage return
  139          * values.
  140          */
  141         if (auio.uio_resid > SSIZE_MAX) {
  142                 error = EINVAL;
  143                 goto out;
  144         }
  145 
  146 #ifdef KTRACE
  147         /*
  148          * if tracing, save a copy of iovec
  149          */
  150         if (KTRPOINT(p, KTR_GENIO))
  151                 ktriov = aiov;
  152 #endif
  153         cnt = auio.uio_resid;
  154         error = (*fp->f_ops->fo_read)(fp, offset, &auio, fp->f_cred, flags);
  155         if (error)
  156                 if (auio.uio_resid != cnt && (error == ERESTART ||
  157                     error == EINTR || error == EWOULDBLOCK))
  158                         error = 0;
  159         cnt -= auio.uio_resid;
  160 #ifdef KTRACE
  161         if (KTRPOINT(p, KTR_GENIO) && error == 0)
  162                 ktrgenio(l, fd, UIO_READ, &ktriov, cnt, error);
  163 #endif
  164         *retval = cnt;
  165  out:
  166         FILE_UNUSE(fp, l);
  167         uvmspace_free(vm);
  168         return (error);
  169 }
  170 
  171 /*
  172  * Scatter read system call.
  173  */
  174 int
  175 sys_readv(struct lwp *l, void *v, register_t *retval)
  176 {
  177         struct sys_readv_args /* {
  178                 syscallarg(int)                         fd;
  179                 syscallarg(const struct iovec *)        iovp;
  180                 syscallarg(int)                         iovcnt;
  181         } */ *uap = v;
  182         struct filedesc *fdp;
  183         struct file *fp;
  184         struct proc *p;
  185         int fd;
  186 
  187         fd = SCARG(uap, fd);
  188         p = l->l_proc;
  189         fdp = p->p_fd;
  190 
  191         if ((fp = fd_getfile(fdp, fd)) == NULL)
  192                 return (EBADF);
  193 
  194         if ((fp->f_flag & FREAD) == 0) {
  195                 simple_unlock(&fp->f_slock);
  196                 return (EBADF);
  197         }
  198 
  199         FILE_USE(fp);
  200 
  201         /* dofilereadv() will unuse the descriptor for us */
  202         return (dofilereadv(l, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt),
  203             &fp->f_offset, FOF_UPDATE_OFFSET, retval));
  204 }
  205 
  206 int
  207 dofilereadv(struct lwp *l, int fd, struct file *fp, const struct iovec *iovp,
  208         int iovcnt, off_t *offset, int flags, register_t *retval)
  209 {
  210         struct proc *p;
  211         struct uio      auio;
  212         struct iovec    *iov, *needfree, aiov[UIO_SMALLIOV];
  213         struct vmspace  *vm;
  214         int             i, error;
  215         size_t          cnt;
  216         u_int           iovlen;
  217 #ifdef KTRACE
  218         struct iovec    *ktriov;
  219 #endif
  220 
  221         p = l->l_proc;
  222         error = proc_vmspace_getref(p, &vm);
  223         if (error) {
  224                 FILE_UNUSE(fp, l);
  225                 return error;
  226         }
  227 
  228 #ifdef KTRACE
  229         ktriov = NULL;
  230 #endif
  231         /* note: can't use iovlen until iovcnt is validated */
  232         iovlen = iovcnt * sizeof(struct iovec);
  233         if ((u_int)iovcnt > UIO_SMALLIOV) {
  234                 if ((u_int)iovcnt > IOV_MAX) {
  235                         error = EINVAL;
  236                         goto out;
  237                 }
  238                 iov = malloc(iovlen, M_IOV, M_WAITOK);
  239                 needfree = iov;
  240         } else if ((u_int)iovcnt > 0) {
  241                 iov = aiov;
  242                 needfree = NULL;
  243         } else {
  244                 error = EINVAL;
  245                 goto out;
  246         }
  247 
  248         auio.uio_iov = iov;
  249         auio.uio_iovcnt = iovcnt;
  250         auio.uio_rw = UIO_READ;
  251         auio.uio_vmspace = vm;
  252         error = copyin(iovp, iov, iovlen);
  253         if (error)
  254                 goto done;
  255         auio.uio_resid = 0;
  256         for (i = 0; i < iovcnt; i++) {
  257                 auio.uio_resid += iov->iov_len;
  258                 /*
  259                  * Reads return ssize_t because -1 is returned on error.
  260                  * Therefore we must restrict the length to SSIZE_MAX to
  261                  * avoid garbage return values.
  262                  */
  263                 if (iov->iov_len > SSIZE_MAX || auio.uio_resid > SSIZE_MAX) {
  264                         error = EINVAL;
  265                         goto done;
  266                 }
  267                 iov++;
  268         }
  269 #ifdef KTRACE
  270         /*
  271          * if tracing, save a copy of iovec
  272          */
  273         if (KTRPOINT(p, KTR_GENIO))  {
  274                 ktriov = malloc(iovlen, M_TEMP, M_WAITOK);
  275                 memcpy((caddr_t)ktriov, (caddr_t)auio.uio_iov, iovlen);
  276         }
  277 #endif
  278         cnt = auio.uio_resid;
  279         error = (*fp->f_ops->fo_read)(fp, offset, &auio, fp->f_cred, flags);
  280         if (error)
  281                 if (auio.uio_resid != cnt && (error == ERESTART ||
  282                     error == EINTR || error == EWOULDBLOCK))
  283                         error = 0;
  284         cnt -= auio.uio_resid;
  285 #ifdef KTRACE
  286         if (ktriov != NULL) {
  287                 if (KTRPOINT(p, KTR_GENIO) && (error == 0))
  288                         ktrgenio(l, fd, UIO_READ, ktriov, cnt, error);
  289                 free(ktriov, M_TEMP);
  290         }
  291 #endif
  292         *retval = cnt;
  293  done:
  294         if (needfree)
  295                 free(needfree, M_IOV);
  296  out:
  297         FILE_UNUSE(fp, l);
  298         uvmspace_free(vm);
  299         return (error);
  300 }
  301 
  302 /*
  303  * Write system call
  304  */
  305 int
  306 sys_write(struct lwp *l, void *v, register_t *retval)
  307 {
  308         struct sys_write_args /* {
  309                 syscallarg(int)                 fd;
  310                 syscallarg(const void *)        buf;
  311                 syscallarg(size_t)              nbyte;
  312         } */ *uap = v;
  313         int             fd;
  314         struct file     *fp;
  315         struct proc     *p;
  316         struct filedesc *fdp;
  317 
  318         fd = SCARG(uap, fd);
  319         p = l->l_proc;
  320         fdp = p->p_fd;
  321 
  322         if ((fp = fd_getfile(fdp, fd)) == NULL)
  323                 return (EBADF);
  324 
  325         if ((fp->f_flag & FWRITE) == 0) {
  326                 simple_unlock(&fp->f_slock);
  327                 return (EBADF);
  328         }
  329 
  330         FILE_USE(fp);
  331 
  332         /* dofilewrite() will unuse the descriptor for us */
  333         return (dofilewrite(l, fd, fp, SCARG(uap, buf), SCARG(uap, nbyte),
  334             &fp->f_offset, FOF_UPDATE_OFFSET, retval));
  335 }
  336 
  337 int
  338 dofilewrite(struct lwp *l, int fd, struct file *fp, const void *buf,
  339         size_t nbyte, off_t *offset, int flags, register_t *retval)
  340 {
  341         struct iovec aiov;
  342         struct uio auio;
  343         struct proc *p;
  344         struct vmspace *vm;
  345         size_t cnt;
  346         int error;
  347 #ifdef KTRACE
  348         struct iovec    ktriov = { .iov_base = NULL, };
  349 #endif
  350 
  351         p = l->l_proc;
  352         error = proc_vmspace_getref(p, &vm);
  353         if (error) {
  354                 FILE_UNUSE(fp, l);
  355                 return error;
  356         }
  357         aiov.iov_base = __UNCONST(buf);         /* XXXUNCONST kills const */
  358         aiov.iov_len = nbyte;
  359         auio.uio_iov = &aiov;
  360         auio.uio_iovcnt = 1;
  361         auio.uio_resid = nbyte;
  362         auio.uio_rw = UIO_WRITE;
  363         auio.uio_vmspace = vm;
  364 
  365         /*
  366          * Writes return ssize_t because -1 is returned on error.  Therefore
  367          * we must restrict the length to SSIZE_MAX to avoid garbage return
  368          * values.
  369          */
  370         if (auio.uio_resid > SSIZE_MAX) {
  371                 error = EINVAL;
  372                 goto out;
  373         }
  374 
  375 #ifdef KTRACE
  376         /*
  377          * if tracing, save a copy of iovec
  378          */
  379         if (KTRPOINT(p, KTR_GENIO))
  380                 ktriov = aiov;
  381 #endif
  382         cnt = auio.uio_resid;
  383         error = (*fp->f_ops->fo_write)(fp, offset, &auio, fp->f_cred, flags);
  384         if (error) {
  385                 if (auio.uio_resid != cnt && (error == ERESTART ||
  386                     error == EINTR || error == EWOULDBLOCK))
  387                         error = 0;
  388                 if (error == EPIPE)
  389                         psignal(p, SIGPIPE);
  390         }
  391         cnt -= auio.uio_resid;
  392 #ifdef KTRACE
  393         if (KTRPOINT(p, KTR_GENIO) && error == 0)
  394                 ktrgenio(l, fd, UIO_WRITE, &ktriov, cnt, error);
  395 #endif
  396         *retval = cnt;
  397  out:
  398         FILE_UNUSE(fp, l);
  399         uvmspace_free(vm);
  400         return (error);
  401 }
  402 
  403 /*
  404  * Gather write system call
  405  */
  406 int
  407 sys_writev(struct lwp *l, void *v, register_t *retval)
  408 {
  409         struct sys_writev_args /* {
  410                 syscallarg(int)                         fd;
  411                 syscallarg(const struct iovec *)        iovp;
  412                 syscallarg(int)                         iovcnt;
  413         } */ *uap = v;
  414         int             fd;
  415         struct file     *fp;
  416         struct proc     *p;
  417         struct filedesc *fdp;
  418 
  419         fd = SCARG(uap, fd);
  420         p = l->l_proc;
  421         fdp = p->p_fd;
  422 
  423         if ((fp = fd_getfile(fdp, fd)) == NULL)
  424                 return (EBADF);
  425 
  426         if ((fp->f_flag & FWRITE) == 0) {
  427                 simple_unlock(&fp->f_slock);
  428                 return (EBADF);
  429         }
  430 
  431         FILE_USE(fp);
  432 
  433         /* dofilewritev() will unuse the descriptor for us */
  434         return (dofilewritev(l, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt),
  435             &fp->f_offset, FOF_UPDATE_OFFSET, retval));
  436 }
  437 
  438 int
  439 dofilewritev(struct lwp *l, int fd, struct file *fp, const struct iovec *iovp,
  440         int iovcnt, off_t *offset, int flags, register_t *retval)
  441 {
  442         struct proc     *p;
  443         struct uio      auio;
  444         struct iovec    *iov, *needfree, aiov[UIO_SMALLIOV];
  445         struct vmspace  *vm;
  446         int             i, error;
  447         size_t          cnt;
  448         u_int           iovlen;
  449 #ifdef KTRACE
  450         struct iovec    *ktriov;
  451 #endif
  452 
  453         p = l->l_proc;
  454         error = proc_vmspace_getref(p, &vm);
  455         if (error) {
  456                 FILE_UNUSE(fp, l);
  457                 return error;
  458         }
  459 #ifdef KTRACE
  460         ktriov = NULL;
  461 #endif
  462         /* note: can't use iovlen until iovcnt is validated */
  463         iovlen = iovcnt * sizeof(struct iovec);
  464         if ((u_int)iovcnt > UIO_SMALLIOV) {
  465                 if ((u_int)iovcnt > IOV_MAX) {
  466                         error = EINVAL;
  467                         goto out;
  468                 }
  469                 iov = malloc(iovlen, M_IOV, M_WAITOK);
  470                 needfree = iov;
  471         } else if ((u_int)iovcnt > 0) {
  472                 iov = aiov;
  473                 needfree = NULL;
  474         } else {
  475                 error = EINVAL;
  476                 goto out;
  477         }
  478 
  479         auio.uio_iov = iov;
  480         auio.uio_iovcnt = iovcnt;
  481         auio.uio_rw = UIO_WRITE;
  482         auio.uio_vmspace = vm;
  483         error = copyin(iovp, iov, iovlen);
  484         if (error)
  485                 goto done;
  486         auio.uio_resid = 0;
  487         for (i = 0; i < iovcnt; i++) {
  488                 auio.uio_resid += iov->iov_len;
  489                 /*
  490                  * Writes return ssize_t because -1 is returned on error.
  491                  * Therefore we must restrict the length to SSIZE_MAX to
  492                  * avoid garbage return values.
  493                  */
  494                 if (iov->iov_len > SSIZE_MAX || auio.uio_resid > SSIZE_MAX) {
  495                         error = EINVAL;
  496                         goto done;
  497                 }
  498                 iov++;
  499         }
  500 #ifdef KTRACE
  501         /*
  502          * if tracing, save a copy of iovec
  503          */
  504         if (KTRPOINT(p, KTR_GENIO))  {
  505                 ktriov = malloc(iovlen, M_TEMP, M_WAITOK);
  506                 memcpy((caddr_t)ktriov, (caddr_t)auio.uio_iov, iovlen);
  507         }
  508 #endif
  509         cnt = auio.uio_resid;
  510         error = (*fp->f_ops->fo_write)(fp, offset, &auio, fp->f_cred, flags);
  511         if (error) {
  512                 if (auio.uio_resid != cnt && (error == ERESTART ||
  513                     error == EINTR || error == EWOULDBLOCK))
  514                         error = 0;
  515                 if (error == EPIPE)
  516                         psignal(p, SIGPIPE);
  517         }
  518         cnt -= auio.uio_resid;
  519 #ifdef KTRACE
  520         if (ktriov != NULL) {
  521                 if (KTRPOINT(p, KTR_GENIO) && (error == 0))
  522                         ktrgenio(l, fd, UIO_WRITE, ktriov, cnt, error);
  523                 free(ktriov, M_TEMP);
  524         }
  525 #endif
  526         *retval = cnt;
  527  done:
  528         if (needfree)
  529                 free(needfree, M_IOV);
  530  out:
  531         FILE_UNUSE(fp, l);
  532         uvmspace_free(vm);
  533         return (error);
  534 }
  535 
  536 /*
  537  * Ioctl system call
  538  */
  539 /* ARGSUSED */
  540 int
  541 sys_ioctl(struct lwp *l, void *v, register_t *retval)
  542 {
  543         struct sys_ioctl_args /* {
  544                 syscallarg(int)         fd;
  545                 syscallarg(u_long)      com;
  546                 syscallarg(caddr_t)     data;
  547         } */ *uap = v;
  548         struct file     *fp;
  549         struct proc     *p;
  550         struct filedesc *fdp;
  551         u_long          com;
  552         int             error;
  553         u_int           size;
  554         caddr_t         data, memp;
  555 #define STK_PARAMS      128
  556         u_long          stkbuf[STK_PARAMS/sizeof(u_long)];
  557 
  558         error = 0;
  559         p = l->l_proc;
  560         fdp = p->p_fd;
  561 
  562         if ((fp = fd_getfile(fdp, SCARG(uap, fd))) == NULL)
  563                 return (EBADF);
  564 
  565         FILE_USE(fp);
  566 
  567         if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
  568                 error = EBADF;
  569                 com = 0;
  570                 goto out;
  571         }
  572 
  573         switch (com = SCARG(uap, com)) {
  574         case FIONCLEX:
  575                 fdp->fd_ofileflags[SCARG(uap, fd)] &= ~UF_EXCLOSE;
  576                 goto out;
  577 
  578         case FIOCLEX:
  579                 fdp->fd_ofileflags[SCARG(uap, fd)] |= UF_EXCLOSE;
  580                 goto out;
  581         }
  582 
  583         /*
  584          * Interpret high order word to find amount of data to be
  585          * copied to/from the user's address space.
  586          */
  587         size = IOCPARM_LEN(com);
  588         if (size > IOCPARM_MAX) {
  589                 error = ENOTTY;
  590                 goto out;
  591         }
  592         memp = NULL;
  593         if (size > sizeof(stkbuf)) {
  594                 memp = (caddr_t)malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
  595                 data = memp;
  596         } else
  597                 data = (caddr_t)stkbuf;
  598         if (com&IOC_IN) {
  599                 if (size) {
  600                         error = copyin(SCARG(uap, data), data, size);
  601                         if (error) {
  602                                 if (memp)
  603                                         free(memp, M_IOCTLOPS);
  604                                 goto out;
  605                         }
  606 #ifdef KTRACE
  607                         if (KTRPOINT(p, KTR_GENIO)) {
  608                                 struct iovec iov;
  609                                 iov.iov_base = SCARG(uap, data);
  610                                 iov.iov_len = size;
  611                                 ktrgenio(l, SCARG(uap, fd), UIO_WRITE, &iov,
  612                                         size, 0);
  613                         }
  614 #endif
  615                 } else
  616                         *(caddr_t *)data = SCARG(uap, data);
  617         } else if ((com&IOC_OUT) && size)
  618                 /*
  619                  * Zero the buffer so the user always
  620                  * gets back something deterministic.
  621                  */
  622                 memset(data, 0, size);
  623         else if (com&IOC_VOID)
  624                 *(caddr_t *)data = SCARG(uap, data);
  625 
  626         switch (com) {
  627 
  628         case FIONBIO:
  629                 if (*(int *)data != 0)
  630                         fp->f_flag |= FNONBLOCK;
  631                 else
  632                         fp->f_flag &= ~FNONBLOCK;
  633                 error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, data, l);
  634                 break;
  635 
  636         case FIOASYNC:
  637                 if (*(int *)data != 0)
  638                         fp->f_flag |= FASYNC;
  639                 else
  640                         fp->f_flag &= ~FASYNC;
  641                 error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, data, l);
  642                 break;
  643 
  644         default:
  645                 error = (*fp->f_ops->fo_ioctl)(fp, com, data, l);
  646                 /*
  647                  * Copy any data to user, size was
  648                  * already set and checked above.
  649                  */
  650                 if (error == 0 && (com&IOC_OUT) && size) {
  651                         error = copyout(data, SCARG(uap, data), size);
  652 #ifdef KTRACE
  653                         if (KTRPOINT(p, KTR_GENIO)) {
  654                                 struct iovec iov;
  655                                 iov.iov_base = SCARG(uap, data);
  656                                 iov.iov_len = size;
  657                                 ktrgenio(l, SCARG(uap, fd), UIO_READ, &iov,
  658                                         size, error);
  659                         }
  660 #endif
  661                 }
  662                 break;
  663         }
  664         if (memp)
  665                 free(memp, M_IOCTLOPS);
  666  out:
  667         FILE_UNUSE(fp, l);
  668         switch (error) {
  669         case -1:
  670                 printf("sys_ioctl: _IO%s%s('%c', %lu, %lu) returned -1: "
  671                     "pid=%d comm=%s\n",
  672                     (com & IOC_IN) ? "W" : "", (com & IOC_OUT) ? "R" : "",
  673                     (char)IOCGROUP(com), (com & 0xff), IOCPARM_LEN(com),
  674                     p->p_pid, p->p_comm);
  675                 /* FALLTHROUGH */
  676         case EPASSTHROUGH:
  677                 error = ENOTTY;
  678                 /* FALLTHROUGH */
  679         default:
  680                 return (error);
  681         }
  682 }
  683 
  684 int     selwait, nselcoll;
  685 
  686 /*
  687  * Select system call.
  688  */
  689 int
  690 sys_pselect(struct lwp *l, void *v, register_t *retval)
  691 {
  692         struct sys_pselect_args /* {
  693                 syscallarg(int)                         nd;
  694                 syscallarg(fd_set *)                    in;
  695                 syscallarg(fd_set *)                    ou;
  696                 syscallarg(fd_set *)                    ex;
  697                 syscallarg(const struct timespec *)     ts;
  698                 syscallarg(sigset_t *)                  mask;
  699         } */ * const uap = v;
  700         struct timespec ats;
  701         struct timeval  atv, *tv = NULL;
  702         sigset_t        amask, *mask = NULL;
  703         int             error;
  704 
  705         if (SCARG(uap, ts)) {
  706                 error = copyin(SCARG(uap, ts), &ats, sizeof(ats));
  707                 if (error)
  708                         return error;
  709                 atv.tv_sec = ats.tv_sec;
  710                 atv.tv_usec = ats.tv_nsec / 1000;
  711                 tv = &atv;
  712         }
  713         if (SCARG(uap, mask) != NULL) {
  714                 error = copyin(SCARG(uap, mask), &amask, sizeof(amask));
  715                 if (error)
  716                         return error;
  717                 mask = &amask;
  718         }
  719 
  720         return selcommon(l, retval, SCARG(uap, nd), SCARG(uap, in),
  721             SCARG(uap, ou), SCARG(uap, ex), tv, mask);
  722 }
  723 
  724 int
  725 inittimeleft(struct timeval *tv, struct timeval *sleeptv)
  726 {
  727         if (itimerfix(tv))
  728                 return -1;
  729         getmicrouptime(sleeptv);
  730         return 0;
  731 }
  732 
  733 int
  734 gettimeleft(struct timeval *tv, struct timeval *sleeptv)
  735 {
  736         /*
  737          * We have to recalculate the timeout on every retry.
  738          */
  739         struct timeval slepttv;
  740         /*
  741          * reduce tv by elapsed time
  742          * based on monotonic time scale
  743          */
  744         getmicrouptime(&slepttv);
  745         timeradd(tv, sleeptv, tv);
  746         timersub(tv, &slepttv, tv);
  747         *sleeptv = slepttv;
  748         return tvtohz(tv);
  749 }
  750 
  751 int
  752 sys_select(struct lwp *l, void *v, register_t *retval)
  753 {
  754         struct sys_select_args /* {
  755                 syscallarg(int)                 nd;
  756                 syscallarg(fd_set *)            in;
  757                 syscallarg(fd_set *)            ou;
  758                 syscallarg(fd_set *)            ex;
  759                 syscallarg(struct timeval *)    tv;
  760         } */ * const uap = v;
  761         struct timeval atv, *tv = NULL;
  762         int error;
  763 
  764         if (SCARG(uap, tv)) {
  765                 error = copyin(SCARG(uap, tv), (caddr_t)&atv,
  766                         sizeof(atv));
  767                 if (error)
  768                         return error;
  769                 tv = &atv;
  770         }
  771 
  772         return selcommon(l, retval, SCARG(uap, nd), SCARG(uap, in),
  773             SCARG(uap, ou), SCARG(uap, ex), tv, NULL);
  774 }
  775 
  776 int
  777 selcommon(struct lwp *l, register_t *retval, int nd, fd_set *u_in,
  778         fd_set *u_ou, fd_set *u_ex, struct timeval *tv, sigset_t *mask)
  779 {
  780         char            smallbits[howmany(FD_SETSIZE, NFDBITS) *
  781                             sizeof(fd_mask) * 6];
  782         struct proc     * const p = l->l_proc;
  783         caddr_t         bits;
  784         int             s, ncoll, error, timo;
  785         size_t          ni;
  786         sigset_t        oldmask;
  787         struct timeval  sleeptv;
  788 
  789         error = 0;
  790         if (nd < 0)
  791                 return (EINVAL);
  792         if (nd > p->p_fd->fd_nfiles) {
  793                 /* forgiving; slightly wrong */
  794                 nd = p->p_fd->fd_nfiles;
  795         }
  796         ni = howmany(nd, NFDBITS) * sizeof(fd_mask);
  797         if (ni * 6 > sizeof(smallbits))
  798                 bits = malloc(ni * 6, M_TEMP, M_WAITOK);
  799         else
  800                 bits = smallbits;
  801 
  802 #define getbits(name, x)                                                \
  803         if (u_ ## name) {                                               \
  804                 error = copyin(u_ ## name, bits + ni * x, ni);          \
  805                 if (error)                                              \
  806                         goto done;                                      \
  807         } else                                                          \
  808                 memset(bits + ni * x, 0, ni);
  809         getbits(in, 0);
  810         getbits(ou, 1);
  811         getbits(ex, 2);
  812 #undef  getbits
  813 
  814         timo = 0;
  815         if (tv && inittimeleft(tv, &sleeptv) == -1) {
  816                 error = EINVAL;
  817                 goto done;
  818         }
  819 
  820         if (mask)
  821                 (void)sigprocmask1(p, SIG_SETMASK, mask, &oldmask);
  822 
  823  retry:
  824         ncoll = nselcoll;
  825         l->l_flag |= L_SELECT;
  826         error = selscan(l, (fd_mask *)(bits + ni * 0),
  827                            (fd_mask *)(bits + ni * 3), nd, retval);
  828         if (error || *retval)
  829                 goto donemask;
  830         if (tv && (timo = gettimeleft(tv, &sleeptv)) <= 0)
  831                 goto donemask;
  832         s = splsched();
  833         if ((l->l_flag & L_SELECT) == 0 || nselcoll != ncoll) {
  834                 splx(s);
  835                 goto retry;
  836         }
  837         l->l_flag &= ~L_SELECT;
  838         error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo);
  839         splx(s);
  840         if (error == 0)
  841                 goto retry;
  842  donemask:
  843         if (mask)
  844                 (void)sigprocmask1(p, SIG_SETMASK, &oldmask, NULL);
  845         l->l_flag &= ~L_SELECT;
  846  done:
  847         /* select is not restarted after signals... */
  848         if (error == ERESTART)
  849                 error = EINTR;
  850         if (error == EWOULDBLOCK)
  851                 error = 0;
  852         if (error == 0) {
  853 
  854 #define putbits(name, x)                                                \
  855                 if (u_ ## name) {                                       \
  856                         error = copyout(bits + ni * x, u_ ## name, ni); \
  857                         if (error)                                      \
  858                                 goto out;                               \
  859                 }
  860                 putbits(in, 3);
  861                 putbits(ou, 4);
  862                 putbits(ex, 5);
  863 #undef putbits
  864         }
  865  out:
  866         if (ni * 6 > sizeof(smallbits))
  867                 free(bits, M_TEMP);
  868         return (error);
  869 }
  870 
  871 int
  872 selscan(struct lwp *l, fd_mask *ibitp, fd_mask *obitp, int nfd,
  873         register_t *retval)
  874 {
  875         static const int flag[3] = { POLLRDNORM | POLLHUP | POLLERR,
  876                                POLLWRNORM | POLLHUP | POLLERR,
  877                                POLLRDBAND };
  878         struct proc *p = l->l_proc;
  879         struct filedesc *fdp;
  880         int msk, i, j, fd, n;
  881         fd_mask ibits, obits;
  882         struct file *fp;
  883 
  884         fdp = p->p_fd;
  885         n = 0;
  886         for (msk = 0; msk < 3; msk++) {
  887                 for (i = 0; i < nfd; i += NFDBITS) {
  888                         ibits = *ibitp++;
  889                         obits = 0;
  890                         while ((j = ffs(ibits)) && (fd = i + --j) < nfd) {
  891                                 ibits &= ~(1 << j);
  892                                 if ((fp = fd_getfile(fdp, fd)) == NULL)
  893                                         return (EBADF);
  894                                 FILE_USE(fp);
  895                                 if ((*fp->f_ops->fo_poll)(fp, flag[msk], l)) {
  896                                         obits |= (1 << j);
  897                                         n++;
  898                                 }
  899                                 FILE_UNUSE(fp, l);
  900                         }
  901                         *obitp++ = obits;
  902                 }
  903         }
  904         *retval = n;
  905         return (0);
  906 }
  907 
  908 /*
  909  * Poll system call.
  910  */
  911 int
  912 sys_poll(struct lwp *l, void *v, register_t *retval)
  913 {
  914         struct sys_poll_args /* {
  915                 syscallarg(struct pollfd *)     fds;
  916                 syscallarg(u_int)               nfds;
  917                 syscallarg(int)                 timeout;
  918         } */ * const uap = v;
  919         struct timeval  atv, *tv = NULL;
  920 
  921         if (SCARG(uap, timeout) != INFTIM) {
  922                 atv.tv_sec = SCARG(uap, timeout) / 1000;
  923                 atv.tv_usec = (SCARG(uap, timeout) % 1000) * 1000;
  924                 tv = &atv;
  925         }
  926 
  927         return pollcommon(l, retval, SCARG(uap, fds), SCARG(uap, nfds),
  928                 tv, NULL);
  929 }
  930 
  931 /*
  932  * Poll system call.
  933  */
  934 int
  935 sys_pollts(struct lwp *l, void *v, register_t *retval)
  936 {
  937         struct sys_pollts_args /* {
  938                 syscallarg(struct pollfd *)             fds;
  939                 syscallarg(u_int)                       nfds;
  940                 syscallarg(const struct timespec *)     ts;
  941                 syscallarg(const sigset_t *)            mask;
  942         } */ * const uap = v;
  943         struct timespec ats;
  944         struct timeval  atv, *tv = NULL;
  945         sigset_t        amask, *mask = NULL;
  946         int             error;
  947 
  948         if (SCARG(uap, ts)) {
  949                 error = copyin(SCARG(uap, ts), &ats, sizeof(ats));
  950                 if (error)
  951                         return error;
  952                 atv.tv_sec = ats.tv_sec;
  953                 atv.tv_usec = ats.tv_nsec / 1000;
  954                 tv = &atv;
  955         }
  956         if (SCARG(uap, mask)) {
  957                 error = copyin(SCARG(uap, mask), &amask, sizeof(amask));
  958                 if (error)
  959                         return error;
  960                 mask = &amask;
  961         }
  962 
  963         return pollcommon(l, retval, SCARG(uap, fds), SCARG(uap, nfds),
  964                 tv, mask);
  965 }
  966 
  967 int
  968 pollcommon(struct lwp *l, register_t *retval,
  969         struct pollfd *u_fds, u_int nfds,
  970         struct timeval *tv, sigset_t *mask)
  971 {
  972         char            smallbits[32 * sizeof(struct pollfd)];
  973         struct proc     * const p = l->l_proc;
  974         caddr_t         bits;
  975         sigset_t        oldmask;
  976         int             s, ncoll, error, timo;
  977         size_t          ni;
  978         struct timeval  sleeptv;
  979 
  980         if (nfds > p->p_fd->fd_nfiles) {
  981                 /* forgiving; slightly wrong */
  982                 nfds = p->p_fd->fd_nfiles;
  983         }
  984         ni = nfds * sizeof(struct pollfd);
  985         if (ni > sizeof(smallbits))
  986                 bits = malloc(ni, M_TEMP, M_WAITOK);
  987         else
  988                 bits = smallbits;
  989 
  990         error = copyin(u_fds, bits, ni);
  991         if (error)
  992                 goto done;
  993 
  994         timo = 0;
  995         if (tv && inittimeleft(tv, &sleeptv) == -1) {
  996                 error = EINVAL;
  997                 goto done;
  998         }
  999 
 1000         if (mask != NULL)
 1001                 (void)sigprocmask1(p, SIG_SETMASK, mask, &oldmask);
 1002 
 1003  retry:
 1004         ncoll = nselcoll;
 1005         l->l_flag |= L_SELECT;
 1006         error = pollscan(l, (struct pollfd *)bits, nfds, retval);
 1007         if (error || *retval)
 1008                 goto donemask;
 1009         if (tv && (timo = gettimeleft(tv, &sleeptv)) <= 0)
 1010                 goto donemask;
 1011         s = splsched();
 1012         if ((l->l_flag & L_SELECT) == 0 || nselcoll != ncoll) {
 1013                 splx(s);
 1014                 goto retry;
 1015         }
 1016         l->l_flag &= ~L_SELECT;
 1017         error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "poll", timo);
 1018         splx(s);
 1019         if (error == 0)
 1020                 goto retry;
 1021  donemask:
 1022         if (mask != NULL)
 1023                 (void)sigprocmask1(p, SIG_SETMASK, &oldmask, NULL);
 1024         l->l_flag &= ~L_SELECT;
 1025  done:
 1026         /* poll is not restarted after signals... */
 1027         if (error == ERESTART)
 1028                 error = EINTR;
 1029         if (error == EWOULDBLOCK)
 1030                 error = 0;
 1031         if (error == 0) {
 1032                 error = copyout(bits, u_fds, ni);
 1033                 if (error)
 1034                         goto out;
 1035         }
 1036  out:
 1037         if (ni > sizeof(smallbits))
 1038                 free(bits, M_TEMP);
 1039         return (error);
 1040 }
 1041 
 1042 int
 1043 pollscan(struct lwp *l, struct pollfd *fds, int nfd, register_t *retval)
 1044 {
 1045         struct proc     *p = l->l_proc;
 1046         struct filedesc *fdp;
 1047         int             i, n;
 1048         struct file     *fp;
 1049 
 1050         fdp = p->p_fd;
 1051         n = 0;
 1052         for (i = 0; i < nfd; i++, fds++) {
 1053                 if (fds->fd >= fdp->fd_nfiles) {
 1054                         fds->revents = POLLNVAL;
 1055                         n++;
 1056                 } else if (fds->fd < 0) {
 1057                         fds->revents = 0;
 1058                 } else {
 1059                         if ((fp = fd_getfile(fdp, fds->fd)) == NULL) {
 1060                                 fds->revents = POLLNVAL;
 1061                                 n++;
 1062                         } else {
 1063                                 FILE_USE(fp);
 1064                                 fds->revents = (*fp->f_ops->fo_poll)(fp,
 1065                                     fds->events | POLLERR | POLLHUP, l);
 1066                                 if (fds->revents != 0)
 1067                                         n++;
 1068                                 FILE_UNUSE(fp, l);
 1069                         }
 1070                 }
 1071         }
 1072         *retval = n;
 1073         return (0);
 1074 }
 1075 
 1076 /*ARGSUSED*/
 1077 int
 1078 seltrue(dev_t dev, int events, struct lwp *l)
 1079 {
 1080 
 1081         return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
 1082 }
 1083 
 1084 /*
 1085  * Record a select request.
 1086  */
 1087 void
 1088 selrecord(struct lwp *selector, struct selinfo *sip)
 1089 {
 1090         struct lwp      *l;
 1091         struct proc     *p;
 1092         pid_t           mypid;
 1093 
 1094         mypid = selector->l_proc->p_pid;
 1095         if (sip->sel_pid == mypid)
 1096                 return;
 1097         if (sip->sel_pid && (p = pfind(sip->sel_pid))) {
 1098                 LIST_FOREACH(l, &p->p_lwps, l_sibling) {
 1099                         if (l->l_wchan == (caddr_t)&selwait) {
 1100                                 sip->sel_collision = 1;
 1101                                 return;
 1102                         }
 1103                 }
 1104         }
 1105 
 1106         sip->sel_pid = mypid;
 1107 }
 1108 
 1109 /*
 1110  * Do a wakeup when a selectable event occurs.
 1111  */
 1112 void
 1113 selwakeup(sip)
 1114         struct selinfo *sip;
 1115 {
 1116         struct lwp *l;
 1117         struct proc *p;
 1118         int s;
 1119 
 1120         if (sip->sel_pid == 0)
 1121                 return;
 1122         if (sip->sel_collision) {
 1123                 sip->sel_pid = 0;
 1124                 nselcoll++;
 1125                 sip->sel_collision = 0;
 1126                 wakeup((caddr_t)&selwait);
 1127                 return;
 1128         }
 1129         p = pfind(sip->sel_pid);
 1130         sip->sel_pid = 0;
 1131         if (p != NULL) {
 1132                 LIST_FOREACH(l, &p->p_lwps, l_sibling) {
 1133                         SCHED_LOCK(s);
 1134                         if (l->l_wchan == (caddr_t)&selwait) {
 1135                                 if (l->l_stat == LSSLEEP)
 1136                                         setrunnable(l);
 1137                                 else
 1138                                         unsleep(l);
 1139                         } else if (l->l_flag & L_SELECT)
 1140                                 l->l_flag &= ~L_SELECT;
 1141                         SCHED_UNLOCK(s);
 1142                 }
 1143         }
 1144 }

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