/* $OpenBSD: sys_generic.c,v 1.28 2000/11/10 18:15:47 art Exp $ */ /* $NetBSD: sys_generic.c,v 1.24 1996/03/29 00:25:32 cgd Exp $ */ /* * Copyright (c) 1996 Theo de Raadt * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)sys_generic.c 8.5 (Berkeley) 1/21/94 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KTRACE #include #endif #include #include int selscan __P((struct proc *, fd_set *, fd_set *, int, register_t *)); int seltrue __P((dev_t, int, struct proc *)); void pollscan __P((struct proc *, struct pollfd *, int, register_t *)); /* * Read system call. */ /* ARGSUSED */ int sys_read(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_read_args /* { syscallarg(int) fd; syscallarg(void *) buf; syscallarg(size_t) nbyte; } */ *uap = v; int fd = SCARG(uap, fd); struct file *fp; struct filedesc *fdp = p->p_fd; if ((u_int)fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL || #if notyet (fp->f_iflags & FIF_WANTCLOSE) != 0 || #endif (fp->f_flag & FREAD) == 0) return (EBADF); #if notyet FILE_USE(fp); #endif /* dofileread() will unuse the descriptor for us */ return (dofileread(p, fd, fp, SCARG(uap, buf), SCARG(uap, nbyte), &fp->f_offset, retval)); } int dofileread(p, fd, fp, buf, nbyte, offset, retval) struct proc *p; int fd; struct file *fp; void *buf; size_t nbyte; off_t *offset; register_t *retval; { struct uio auio; struct iovec aiov; long cnt, error = 0; #ifdef KTRACE struct iovec ktriov; #endif aiov.iov_base = (caddr_t)buf; aiov.iov_len = nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_resid = nbyte; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_USERSPACE; auio.uio_procp = p; /* * Reads return ssize_t because -1 is returned on error. Therefore * we must restrict the length to SSIZE_MAX to avoid garbage return * values. */ if (auio.uio_resid > SSIZE_MAX) { error = EINVAL; goto out; } #ifdef KTRACE /* * if tracing, save a copy of iovec */ if (KTRPOINT(p, KTR_GENIO)) ktriov = aiov; #endif cnt = auio.uio_resid; error = (*fp->f_ops->fo_read)(fp, offset, &auio, fp->f_cred); if (error) if (auio.uio_resid != cnt && (error == ERESTART || error == EINTR || error == EWOULDBLOCK)) error = 0; cnt -= auio.uio_resid; #ifdef KTRACE if (KTRPOINT(p, KTR_GENIO) && error == 0) ktrgenio(p, fd, UIO_READ, &ktriov, cnt, error); #endif *retval = cnt; out: #if notyet FILE_UNUSE(fp, p); #endif return (error); } /* * Scatter read system call. */ int sys_readv(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_readv_args /* { syscallarg(int) fd; syscallarg(const struct iovec *) iovp; syscallarg(int) iovcnt; } */ *uap = v; int fd = SCARG(uap, fd); struct file *fp; struct filedesc *fdp = p->p_fd; if ((u_int)fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL || #if notyet (fp->f_iflags & FIF_WANTCLOSE) != 0 || #endif (fp->f_flag & FREAD) == 0) return (EBADF); #if notyet FILE_USE(fp); #endif /* dofilereadv() will unuse the descriptor for us */ return (dofilereadv(p, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt), &fp->f_offset, retval)); } int dofilereadv(p, fd, fp, iovp, iovcnt, offset, retval) struct proc *p; int fd; struct file *fp; const struct iovec *iovp; int iovcnt; off_t *offset; register_t *retval; { struct uio auio; struct iovec *iov; struct iovec *needfree; struct iovec aiov[UIO_SMALLIOV]; long i, cnt, error = 0; u_int iovlen; #ifdef KTRACE struct iovec *ktriov = NULL; #endif /* note: can't use iovlen until iovcnt is validated */ iovlen = iovcnt * sizeof(struct iovec); if ((u_int)iovcnt > UIO_SMALLIOV) { if ((u_int)iovcnt > IOV_MAX) { error = EINVAL; goto out; } iov = needfree = malloc(iovlen, M_IOV, M_WAITOK); } else if ((u_int)iovcnt > 0) { iov = aiov; needfree = NULL; } else { error = EINVAL; goto out; } auio.uio_iov = iov; auio.uio_iovcnt = iovcnt; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_USERSPACE; auio.uio_procp = p; error = copyin(iovp, iov, iovlen); if (error) goto done; auio.uio_resid = 0; for (i = 0; i < iovcnt; i++) { auio.uio_resid += iov->iov_len; /* * Reads return ssize_t because -1 is returned on error. * Therefore we must restrict the length to SSIZE_MAX to * avoid garbage return values. */ if (iov->iov_len > SSIZE_MAX || auio.uio_resid > SSIZE_MAX) { error = EINVAL; goto done; } iov++; } #ifdef KTRACE /* * if tracing, save a copy of iovec */ if (KTRPOINT(p, KTR_GENIO)) { ktriov = malloc(iovlen, M_TEMP, M_WAITOK); bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen); } #endif cnt = auio.uio_resid; error = (*fp->f_ops->fo_read)(fp, offset, &auio, fp->f_cred); if (error) if (auio.uio_resid != cnt && (error == ERESTART || error == EINTR || error == EWOULDBLOCK)) error = 0; cnt -= auio.uio_resid; #ifdef KTRACE if (ktriov != NULL) { if (error == 0) ktrgenio(p, fd, UIO_READ, ktriov, cnt, error); free(ktriov, M_TEMP); } #endif *retval = cnt; done: if (needfree) free(needfree, M_IOV); out: #if notyet FILE_UNUSE(fp, p); #endif return (error); } /* * Write system call */ int sys_write(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_write_args /* { syscallarg(int) fd; syscallarg(const void *) buf; syscallarg(size_t) nbyte; } */ *uap = v; int fd = SCARG(uap, fd); struct file *fp; struct filedesc *fdp = p->p_fd; if ((u_int)fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL || #if notyet (fp->f_iflags & FIF_WANTCLOSE) != 0 || #endif (fp->f_flag & FWRITE) == 0) return (EBADF); #if notyet FILE_USE(fp); #endif /* dofilewrite() will unuse the descriptor for us */ return (dofilewrite(p, fd, fp, SCARG(uap, buf), SCARG(uap, nbyte), &fp->f_offset, retval)); } int dofilewrite(p, fd, fp, buf, nbyte, offset, retval) struct proc *p; int fd; struct file *fp; const void *buf; size_t nbyte; off_t *offset; register_t *retval; { struct uio auio; struct iovec aiov; long cnt, error = 0; #ifdef KTRACE struct iovec ktriov; #endif aiov.iov_base = (caddr_t)buf; /* XXX kills const */ aiov.iov_len = nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_resid = nbyte; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_USERSPACE; auio.uio_procp = p; /* * Writes return ssize_t because -1 is returned on error. Therefore * we must restrict the length to SSIZE_MAX to avoid garbage return * values. */ if (auio.uio_resid > SSIZE_MAX) { error = EINVAL; goto out; } #ifdef KTRACE /* * if tracing, save a copy of iovec */ if (KTRPOINT(p, KTR_GENIO)) ktriov = aiov; #endif cnt = auio.uio_resid; error = (*fp->f_ops->fo_write)(fp, offset, &auio, fp->f_cred); if (error) { if (auio.uio_resid != cnt && (error == ERESTART || error == EINTR || error == EWOULDBLOCK)) error = 0; if (error == EPIPE) psignal(p, SIGPIPE); } cnt -= auio.uio_resid; #ifdef KTRACE if (KTRPOINT(p, KTR_GENIO) && error == 0) ktrgenio(p, fd, UIO_WRITE, &ktriov, cnt, error); #endif *retval = cnt; out: #if notyet FILE_UNUSE(fp, p); #endif return (error); } /* * Gather write system call */ int sys_writev(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_writev_args /* { syscallarg(int) fd; syscallarg(const struct iovec *) iovp; syscallarg(int) iovcnt; } */ *uap = v; int fd = SCARG(uap, fd); struct file *fp; struct filedesc *fdp = p->p_fd; if ((u_int)fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL || #if notyet (fp->f_iflags & FIF_WANTCLOSE) != 0 || #endif (fp->f_flag & FWRITE) == 0) return (EBADF); #if notyet FILE_USE(fp); #endif /* dofilewritev() will unuse the descriptor for us */ return (dofilewritev(p, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt), &fp->f_offset, retval)); } int dofilewritev(p, fd, fp, iovp, iovcnt, offset, retval) struct proc *p; int fd; struct file *fp; const struct iovec *iovp; int iovcnt; off_t *offset; register_t *retval; { struct uio auio; struct iovec *iov; struct iovec *needfree; struct iovec aiov[UIO_SMALLIOV]; long i, cnt, error = 0; u_int iovlen; #ifdef KTRACE struct iovec *ktriov = NULL; #endif /* note: can't use iovlen until iovcnt is validated */ iovlen = iovcnt * sizeof(struct iovec); if ((u_int)iovcnt > UIO_SMALLIOV) { if ((u_int)iovcnt > IOV_MAX) return (EINVAL); iov = needfree = malloc(iovlen, M_IOV, M_WAITOK); } else if ((u_int)iovcnt > 0) { iov = aiov; needfree = NULL; } else { error = EINVAL; goto out; } auio.uio_iov = iov; auio.uio_iovcnt = iovcnt; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_USERSPACE; auio.uio_procp = p; error = copyin(iovp, iov, iovlen); if (error) goto done; auio.uio_resid = 0; for (i = 0; i < iovcnt; i++) { auio.uio_resid += iov->iov_len; /* * Writes return ssize_t because -1 is returned on error. * Therefore we must restrict the length to SSIZE_MAX to * avoid garbage return values. */ if (iov->iov_len > SSIZE_MAX || auio.uio_resid > SSIZE_MAX) { error = EINVAL; goto done; } iov++; } #ifdef KTRACE /* * if tracing, save a copy of iovec */ if (KTRPOINT(p, KTR_GENIO)) { ktriov = malloc(iovlen, M_TEMP, M_WAITOK); bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen); } #endif cnt = auio.uio_resid; error = (*fp->f_ops->fo_write)(fp, offset, &auio, fp->f_cred); if (error) { if (auio.uio_resid != cnt && (error == ERESTART || error == EINTR || error == EWOULDBLOCK)) error = 0; if (error == EPIPE) psignal(p, SIGPIPE); } cnt -= auio.uio_resid; #ifdef KTRACE if (ktriov != NULL) { if (error == 0) ktrgenio(p, fd, UIO_WRITE, ktriov, cnt, error); free(ktriov, M_TEMP); } #endif *retval = cnt; done: if (needfree) free(needfree, M_IOV); out: #if notyet FILE_UNUSE(fp, p); #endif return (error); } /* * Ioctl system call */ /* ARGSUSED */ int sys_ioctl(p, v, retval) struct proc *p; void *v; register_t *retval; { register struct sys_ioctl_args /* { syscallarg(int) fd; syscallarg(u_long) com; syscallarg(caddr_t) data; } */ *uap = v; register struct file *fp; register struct filedesc *fdp; register u_long com; register int error; register u_int size; caddr_t data, memp; int tmp; #define STK_PARAMS 128 char stkbuf[STK_PARAMS]; fdp = p->p_fd; if ((u_int)SCARG(uap, fd) >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[SCARG(uap, fd)]) == NULL) return (EBADF); if ((fp->f_flag & (FREAD | FWRITE)) == 0) return (EBADF); switch (com = SCARG(uap, com)) { case FIONCLEX: fdp->fd_ofileflags[SCARG(uap, fd)] &= ~UF_EXCLOSE; return (0); case FIOCLEX: fdp->fd_ofileflags[SCARG(uap, fd)] |= UF_EXCLOSE; return (0); } /* * Interpret high order word to find amount of data to be * copied to/from the user's address space. */ size = IOCPARM_LEN(com); if (size > IOCPARM_MAX) return (ENOTTY); memp = NULL; if (size > sizeof (stkbuf)) { memp = (caddr_t)malloc((u_long)size, M_IOCTLOPS, M_WAITOK); data = memp; } else data = stkbuf; if (com&IOC_IN) { if (size) { error = copyin(SCARG(uap, data), data, (u_int)size); if (error) { if (memp) free(memp, M_IOCTLOPS); return (error); } } else *(caddr_t *)data = SCARG(uap, data); } else if ((com&IOC_OUT) && size) /* * Zero the buffer so the user always * gets back something deterministic. */ bzero(data, size); else if (com&IOC_VOID) *(caddr_t *)data = SCARG(uap, data); switch (com) { case FIONBIO: if ((tmp = *(int *)data) != 0) fp->f_flag |= FNONBLOCK; else fp->f_flag &= ~FNONBLOCK; error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p); break; case FIOASYNC: if ((tmp = *(int *)data) != 0) fp->f_flag |= FASYNC; else fp->f_flag &= ~FASYNC; error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p); break; case FIOSETOWN: tmp = *(int *)data; if (fp->f_type == DTYPE_SOCKET) { struct socket *so = (struct socket *)fp->f_data; so->so_pgid = tmp; so->so_siguid = p->p_cred->p_ruid; so->so_sigeuid = p->p_ucred->cr_uid; error = 0; break; } if (tmp <= 0) { tmp = -tmp; } else { struct proc *p1 = pfind(tmp); if (p1 == 0) { error = ESRCH; break; } tmp = p1->p_pgrp->pg_id; } error = (*fp->f_ops->fo_ioctl) (fp, TIOCSPGRP, (caddr_t)&tmp, p); break; case FIOGETOWN: if (fp->f_type == DTYPE_SOCKET) { error = 0; *(int *)data = ((struct socket *)fp->f_data)->so_pgid; break; } error = (*fp->f_ops->fo_ioctl)(fp, TIOCGPGRP, data, p); *(int *)data = -*(int *)data; break; default: error = (*fp->f_ops->fo_ioctl)(fp, com, data, p); /* * Copy any data to user, size was * already set and checked above. */ if (error == 0 && (com&IOC_OUT) && size) error = copyout(data, SCARG(uap, data), (u_int)size); break; } if (memp) free(memp, M_IOCTLOPS); return (error); } int selwait, nselcoll; /* * Select system call. */ int sys_select(p, v, retval) register struct proc *p; void *v; register_t *retval; { register struct sys_select_args /* { syscallarg(int) nd; syscallarg(fd_set *) in; syscallarg(fd_set *) ou; syscallarg(fd_set *) ex; syscallarg(struct timeval *) tv; } */ *uap = v; fd_set bits[6], *pibits[3], *pobits[3]; struct timeval atv; int s, ncoll, error = 0, timo; u_int ni; if (SCARG(uap, nd) > p->p_fd->fd_nfiles) { /* forgiving; slightly wrong */ SCARG(uap, nd) = p->p_fd->fd_nfiles; } ni = howmany(SCARG(uap, nd), NFDBITS) * sizeof(fd_mask); if (SCARG(uap, nd) > FD_SETSIZE) { caddr_t mbits; if ((mbits = malloc(ni * 6, M_TEMP, M_WAITOK)) == NULL) { error = EINVAL; goto cleanup; } bzero(mbits, ni * 6); pibits[0] = (fd_set *)&mbits[ni * 0]; pibits[1] = (fd_set *)&mbits[ni * 1]; pibits[2] = (fd_set *)&mbits[ni * 2]; pobits[0] = (fd_set *)&mbits[ni * 3]; pobits[1] = (fd_set *)&mbits[ni * 4]; pobits[2] = (fd_set *)&mbits[ni * 5]; } else { bzero((caddr_t)bits, sizeof(bits)); pibits[0] = &bits[0]; pibits[1] = &bits[1]; pibits[2] = &bits[2]; pobits[0] = &bits[3]; pobits[1] = &bits[4]; pobits[2] = &bits[5]; } #define getbits(name, x) \ if (SCARG(uap, name) && (error = copyin((caddr_t)SCARG(uap, name), \ (caddr_t)pibits[x], ni))) \ goto done; getbits(in, 0); getbits(ou, 1); getbits(ex, 2); #undef getbits if (SCARG(uap, tv)) { error = copyin((caddr_t)SCARG(uap, tv), (caddr_t)&atv, sizeof (atv)); if (error) goto done; if (itimerfix(&atv)) { error = EINVAL; goto done; } s = splclock(); timeradd(&atv, &time, &atv); splx(s); } else timo = 0; retry: ncoll = nselcoll; p->p_flag |= P_SELECT; error = selscan(p, pibits[0], pobits[0], SCARG(uap, nd), retval); if (error || *retval) goto done; if (SCARG(uap, tv)) { /* * We have to recalculate the timeout on every retry. */ timo = hzto(&atv); if (timo <= 0) goto done; } s = splhigh(); if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { splx(s); goto retry; } p->p_flag &= ~P_SELECT; error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo); splx(s); if (error == 0) goto retry; done: p->p_flag &= ~P_SELECT; /* select is not restarted after signals... */ if (error == ERESTART) error = EINTR; if (error == EWOULDBLOCK) error = 0; #define putbits(name, x) \ if (SCARG(uap, name) && (error2 = copyout((caddr_t)pobits[x], \ (caddr_t)SCARG(uap, name), ni))) \ error = error2; if (error == 0) { int error2; putbits(in, 0); putbits(ou, 1); putbits(ex, 2); #undef putbits } cleanup: if (pibits[0] != &bits[0]) free(pibits[0], M_TEMP); return (error); } int selscan(p, ibits, obits, nfd, retval) struct proc *p; fd_set *ibits, *obits; int nfd; register_t *retval; { caddr_t cibits = (caddr_t)ibits, cobits = (caddr_t)obits; register struct filedesc *fdp = p->p_fd; register int msk, i, j, fd; register fd_mask bits; struct file *fp; int ni, n = 0; static int flag[3] = { FREAD, FWRITE, 0 }; /* * if nfd > FD_SETSIZE then the fd_set's contain nfd bits (rounded * up to the next byte) otherwise the fd_set's are normal sized. */ ni = sizeof(fd_set); if (nfd > FD_SETSIZE) ni = howmany(nfd, NFDBITS) * sizeof(fd_mask); for (msk = 0; msk < 3; msk++) { fd_set *pibits = (fd_set *)&cibits[msk*ni]; fd_set *pobits = (fd_set *)&cobits[msk*ni]; for (i = 0; i < nfd; i += NFDBITS) { bits = pibits->fds_bits[i/NFDBITS]; while ((j = ffs(bits)) && (fd = i + --j) < nfd) { bits &= ~(1 << j); fp = fdp->fd_ofiles[fd]; if (fp == NULL) return (EBADF); if ((*fp->f_ops->fo_select)(fp, flag[msk], p)) { FD_SET(fd, pobits); n++; } } } } *retval = n; return (0); } /*ARGSUSED*/ int seltrue(dev, flag, p) dev_t dev; int flag; struct proc *p; { return (1); } /* * Record a select request. */ void selrecord(selector, sip) struct proc *selector; struct selinfo *sip; { struct proc *p; pid_t mypid; mypid = selector->p_pid; if (sip->si_selpid == mypid) return; if (sip->si_selpid && (p = pfind(sip->si_selpid)) && p->p_wchan == (caddr_t)&selwait) sip->si_flags |= SI_COLL; else sip->si_selpid = mypid; } /* * Do a wakeup when a selectable event occurs. */ void selwakeup(sip) register struct selinfo *sip; { register struct proc *p; int s; if (sip->si_selpid == 0) return; if (sip->si_flags & SI_COLL) { nselcoll++; sip->si_flags &= ~SI_COLL; wakeup((caddr_t)&selwait); } p = pfind(sip->si_selpid); sip->si_selpid = 0; if (p != NULL) { s = splhigh(); if (p->p_wchan == (caddr_t)&selwait) { if (p->p_stat == SSLEEP) setrunnable(p); else unsleep(p); } else if (p->p_flag & P_SELECT) p->p_flag &= ~P_SELECT; splx(s); } } void pollscan(p, pl, nfd, retval) struct proc *p; struct pollfd *pl; int nfd; register_t *retval; { register struct filedesc *fdp = p->p_fd; register int msk, i; struct file *fp; int x, n = 0; static int flag[3] = { FREAD, FWRITE, 0 }; static int pflag[3] = { POLLIN|POLLRDNORM, POLLOUT, POLLERR }; /* * XXX: We need to implement the rest of the flags. */ for (i = 0; i < nfd; i++) { /* Check the file descriptor. */ if (pl[i].fd < 0) continue; if (pl[i].fd >= fdp->fd_nfiles) { pl[i].revents = POLLNVAL; n++; continue; } fp = fdp->fd_ofiles[pl[i].fd]; if (fp == NULL) { pl[i].revents = POLLNVAL; n++; continue; } for (x = msk = 0; msk < 3; msk++) { if (pl[i].events & pflag[msk]) { if ((*fp->f_ops->fo_select)(fp, flag[msk], p)) { pl[i].revents |= pflag[msk] & pl[i].events; x++; } } } if (x) n++; } *retval = n; } /* * We are using the same mechanism as select only we encode/decode args * differently. */ int sys_poll(p, v, retval) register struct proc *p; void *v; register_t *retval; { struct sys_poll_args *uap = v; size_t sz; struct pollfd pfds[4], *pl = pfds; int msec = SCARG(uap, timeout); struct timeval atv; int timo, ncoll, i, s, error, error2; extern int nselcoll, selwait; /* Standards say no more than MAX_OPEN; this is possibly better. */ if (SCARG(uap, nfds) > min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles)) return (EINVAL); sz = sizeof(struct pollfd) * SCARG(uap, nfds); /* optimize for the default case, of a small nfds value */ if (sz > sizeof(pfds)) pl = (struct pollfd *) malloc(sz, M_TEMP, M_WAITOK); if ((error = copyin(SCARG(uap, fds), pl, sz)) != 0) goto bad; for (i = 0; i < SCARG(uap, nfds); i++) pl[i].revents = 0; if (msec != -1) { atv.tv_sec = msec / 1000; atv.tv_usec = (msec - (atv.tv_sec * 1000)) * 1000; if (itimerfix(&atv)) { error = EINVAL; goto done; } s = splclock(); timeradd(&atv, &time, &atv); splx(s); } else timo = 0; retry: ncoll = nselcoll; p->p_flag |= P_SELECT; pollscan(p, pl, SCARG(uap, nfds), retval); if (*retval) goto done; if (msec != -1) { /* * We have to recalculate the timeout on every retry. */ timo = hzto(&atv); if (timo <= 0) goto done; } s = splhigh(); if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { splx(s); goto retry; } p->p_flag &= ~P_SELECT; error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "poll", timo); splx(s); if (error == 0) goto retry; done: p->p_flag &= ~P_SELECT; /* poll is not restarted after signals... */ if (error == ERESTART) error = EINTR; if (error == EWOULDBLOCK) error = 0; if ((error2 = copyout(pl, SCARG(uap, fds), sz)) != 0) error = error2; bad: if (pl != pfds) free((char *) pl, M_TEMP); return (error); }