/* * 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 * $FreeBSD$ */ #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KTRACE #include #endif #include static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); static MALLOC_DEFINE(M_SELECT, "select", "select() buffer"); MALLOC_DEFINE(M_IOV, "iov", "large iov's"); static int pollscan __P((struct proc *, struct pollfd *, int)); static int selscan __P((struct proc *, fd_mask **, fd_mask **, int)); static int dofileread __P((struct proc *, struct file *, int, void *, size_t, off_t, int)); static int dofilewrite __P((struct proc *, struct file *, int, const void *, size_t, off_t, int)); struct file* getfp(fdp, fd, flag) struct filedesc* fdp; int fd, flag; { struct file* fp; if (((u_int)fd) >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL || (fp->f_flag & flag) == 0) return (NULL); return (fp); } /* * Read system call. */ #ifndef _SYS_SYSPROTO_H_ struct read_args { int fd; void *buf; size_t nbyte; }; #endif int read(p, uap) struct proc *p; register struct read_args *uap; { register struct file *fp; if ((fp = getfp(p->p_fd, uap->fd, FREAD)) == NULL) return (EBADF); return (dofileread(p, fp, uap->fd, uap->buf, uap->nbyte, (off_t)-1, 0)); } /* * Pread system call */ #ifndef _SYS_SYSPROTO_H_ struct pread_args { int fd; void *buf; size_t nbyte; int pad; off_t offset; }; #endif int pread(p, uap) struct proc *p; register struct pread_args *uap; { register struct file *fp; if ((fp = getfp(p->p_fd, uap->fd, FREAD)) == NULL) return (EBADF); if (fp->f_type != DTYPE_VNODE) return (ESPIPE); return (dofileread(p, fp, uap->fd, uap->buf, uap->nbyte, uap->offset, FOF_OFFSET)); } /* * Code common for read and pread */ int dofileread(p, fp, fd, buf, nbyte, offset, flags) struct proc *p; struct file *fp; int fd, flags; void *buf; size_t nbyte; off_t offset; { 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_offset = offset; if (nbyte > INT_MAX) return (EINVAL); auio.uio_resid = nbyte; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_USERSPACE; auio.uio_procp = p; #ifdef KTRACE /* * if tracing, save a copy of iovec */ if (KTRPOINT(p, KTR_GENIO)) ktriov = aiov; #endif cnt = nbyte; if ((error = fo_read(fp, &auio, fp->f_cred, flags, p))) 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->p_tracep, fd, UIO_READ, &ktriov, cnt, error); #endif p->p_retval[0] = cnt; return (error); } /* * Scatter read system call. */ #ifndef _SYS_SYSPROTO_H_ struct readv_args { int fd; struct iovec *iovp; u_int iovcnt; }; #endif int readv(p, uap) struct proc *p; register struct readv_args *uap; { register struct file *fp; register struct filedesc *fdp = p->p_fd; struct uio auio; register 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 if ((fp = getfp(fdp, uap->fd, FREAD)) == NULL) return (EBADF); /* note: can't use iovlen until iovcnt is validated */ iovlen = uap->iovcnt * sizeof (struct iovec); if (uap->iovcnt > UIO_SMALLIOV) { if (uap->iovcnt > UIO_MAXIOV) return (EINVAL); MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK); needfree = iov; } else { iov = aiov; needfree = NULL; } auio.uio_iov = iov; auio.uio_iovcnt = uap->iovcnt; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_USERSPACE; auio.uio_procp = p; auio.uio_offset = -1; if ((error = copyin((caddr_t)uap->iovp, (caddr_t)iov, iovlen))) goto done; auio.uio_resid = 0; for (i = 0; i < uap->iovcnt; i++) { if (iov->iov_len > INT_MAX - auio.uio_resid) { error = EINVAL; goto done; } auio.uio_resid += iov->iov_len; iov++; } #ifdef KTRACE /* * if tracing, save a copy of iovec */ if (KTRPOINT(p, KTR_GENIO)) { MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen); } #endif cnt = auio.uio_resid; if ((error = fo_read(fp, &auio, fp->f_cred, 0, p))) 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->p_tracep, uap->fd, UIO_READ, ktriov, cnt, error); FREE(ktriov, M_TEMP); } #endif p->p_retval[0] = cnt; done: if (needfree) FREE(needfree, M_IOV); return (error); } /* * Write system call */ #ifndef _SYS_SYSPROTO_H_ struct write_args { int fd; const void *buf; size_t nbyte; }; #endif int write(p, uap) struct proc *p; register struct write_args *uap; { register struct file *fp; if ((fp = getfp(p->p_fd, uap->fd, FWRITE)) == NULL) return (EBADF); return (dofilewrite(p, fp, uap->fd, uap->buf, uap->nbyte, (off_t)-1, 0)); } /* * Pwrite system call */ #ifndef _SYS_SYSPROTO_H_ struct pwrite_args { int fd; const void *buf; size_t nbyte; int pad; off_t offset; }; #endif int pwrite(p, uap) struct proc *p; register struct pwrite_args *uap; { register struct file *fp; if ((fp = getfp(p->p_fd, uap->fd, FWRITE)) == NULL) return (EBADF); if (fp->f_type != DTYPE_VNODE) return (ESPIPE); return (dofilewrite(p, fp, uap->fd, uap->buf, uap->nbyte, uap->offset, FOF_OFFSET)); } static int dofilewrite(p, fp, fd, buf, nbyte, offset, flags) struct proc *p; struct file *fp; int fd, flags; const void *buf; size_t nbyte; off_t offset; { struct uio auio; struct iovec aiov; long cnt, error = 0; #ifdef KTRACE struct iovec ktriov; #endif aiov.iov_base = (void *)buf; aiov.iov_len = nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = offset; if (nbyte > INT_MAX) return (EINVAL); auio.uio_resid = nbyte; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_USERSPACE; auio.uio_procp = p; #ifdef KTRACE /* * if tracing, save a copy of iovec */ if (KTRPOINT(p, KTR_GENIO)) ktriov = aiov; #endif cnt = nbyte; if ((error = fo_write(fp, &auio, fp->f_cred, flags, p))) { 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->p_tracep, fd, UIO_WRITE, &ktriov, cnt, error); #endif p->p_retval[0] = cnt; return (error); } /* * Gather write system call */ #ifndef _SYS_SYSPROTO_H_ struct writev_args { int fd; struct iovec *iovp; u_int iovcnt; }; #endif int writev(p, uap) struct proc *p; register struct writev_args *uap; { register struct file *fp; register struct filedesc *fdp = p->p_fd; struct uio auio; register 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 if ((fp = getfp(fdp, uap->fd, FWRITE)) == NULL) return (EBADF); fhold(fp); /* note: can't use iovlen until iovcnt is validated */ iovlen = uap->iovcnt * sizeof (struct iovec); if (uap->iovcnt > UIO_SMALLIOV) { if (uap->iovcnt > UIO_MAXIOV) { needfree = NULL; error = EINVAL; goto done; } MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK); needfree = iov; } else { iov = aiov; needfree = NULL; } auio.uio_iov = iov; auio.uio_iovcnt = uap->iovcnt; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_USERSPACE; auio.uio_procp = p; auio.uio_offset = -1; if ((error = copyin((caddr_t)uap->iovp, (caddr_t)iov, iovlen))) goto done; auio.uio_resid = 0; for (i = 0; i < uap->iovcnt; i++) { if (iov->iov_len > INT_MAX - auio.uio_resid) { error = EINVAL; goto done; } auio.uio_resid += iov->iov_len; iov++; } #ifdef KTRACE /* * if tracing, save a copy of iovec */ if (KTRPOINT(p, KTR_GENIO)) { MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen); } #endif cnt = auio.uio_resid; if ((error = fo_write(fp, &auio, fp->f_cred, 0, p))) { 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->p_tracep, uap->fd, UIO_WRITE, ktriov, cnt, error); FREE(ktriov, M_TEMP); } #endif p->p_retval[0] = cnt; done: fdrop(fp, p); if (needfree) FREE(needfree, M_IOV); return (error); } /* * Ioctl system call */ #ifndef _SYS_SYSPROTO_H_ struct ioctl_args { int fd; u_long com; caddr_t data; }; #endif /* ARGSUSED */ int ioctl(p, uap) struct proc *p; register struct ioctl_args *uap; { register struct file *fp; register struct filedesc *fdp; register u_long com; int error; register u_int size; caddr_t data, memp; int tmp; #define STK_PARAMS 128 union { char stkbuf[STK_PARAMS]; long align; } ubuf; fdp = p->p_fd; if ((u_int)uap->fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[uap->fd]) == NULL) return (EBADF); if ((fp->f_flag & (FREAD | FWRITE)) == 0) return (EBADF); switch (com = uap->com) { case FIONCLEX: fdp->fd_ofileflags[uap->fd] &= ~UF_EXCLOSE; return (0); case FIOCLEX: fdp->fd_ofileflags[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 (ubuf.stkbuf)) { memp = (caddr_t)malloc((u_long)size, M_IOCTLOPS, M_WAITOK); data = memp; } else data = ubuf.stkbuf; if (com&IOC_IN) { if (size) { error = copyin(uap->data, data, (u_int)size); if (error) { if (memp) free(memp, M_IOCTLOPS); return (error); } } else *(caddr_t *)data = 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 = uap->data; switch (com) { case FIONBIO: if ((tmp = *(int *)data)) fp->f_flag |= FNONBLOCK; else fp->f_flag &= ~FNONBLOCK; error = fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, p); break; case FIOASYNC: if ((tmp = *(int *)data)) fp->f_flag |= FASYNC; else fp->f_flag &= ~FASYNC; error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, p); break; default: error = 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, uap->data, (u_int)size); break; } if (memp) free(memp, M_IOCTLOPS); return (error); } static int nselcoll; /* Select collisions since boot */ int selwait; SYSCTL_INT(_kern, OID_AUTO, nselcoll, CTLFLAG_RD, &nselcoll, 0, ""); /* * Select system call. */ #ifndef _SYS_SYSPROTO_H_ struct select_args { int nd; fd_set *in, *ou, *ex; struct timeval *tv; }; #endif int select(p, uap) register struct proc *p; register struct select_args *uap; { /* * The magic 2048 here is chosen to be just enough for FD_SETSIZE * infds with the new FD_SETSIZE of 1024, and more than enough for * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE * of 256. */ fd_mask s_selbits[howmany(2048, NFDBITS)]; fd_mask *ibits[3], *obits[3], *selbits, *sbp; struct timeval atv, rtv, ttv; int s, ncoll, error, timo; u_int nbufbytes, ncpbytes, nfdbits; if (uap->nd < 0) return (EINVAL); if (uap->nd > p->p_fd->fd_nfiles) uap->nd = p->p_fd->fd_nfiles; /* forgiving; slightly wrong */ /* * Allocate just enough bits for the non-null fd_sets. Use the * preallocated auto buffer if possible. */ nfdbits = roundup(uap->nd, NFDBITS); ncpbytes = nfdbits / NBBY; nbufbytes = 0; if (uap->in != NULL) nbufbytes += 2 * ncpbytes; if (uap->ou != NULL) nbufbytes += 2 * ncpbytes; if (uap->ex != NULL) nbufbytes += 2 * ncpbytes; if (nbufbytes <= sizeof s_selbits) selbits = &s_selbits[0]; else selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); /* * Assign pointers into the bit buffers and fetch the input bits. * Put the output buffers together so that they can be bzeroed * together. */ sbp = selbits; #define getbits(name, x) \ do { \ if (uap->name == NULL) \ ibits[x] = NULL; \ else { \ ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ obits[x] = sbp; \ sbp += ncpbytes / sizeof *sbp; \ error = copyin(uap->name, ibits[x], ncpbytes); \ if (error != 0) \ goto done; \ } \ } while (0) getbits(in, 0); getbits(ou, 1); getbits(ex, 2); #undef getbits if (nbufbytes != 0) bzero(selbits, nbufbytes / 2); if (uap->tv) { error = copyin((caddr_t)uap->tv, (caddr_t)&atv, sizeof (atv)); if (error) goto done; if (itimerfix(&atv)) { error = EINVAL; goto done; } getmicrouptime(&rtv); timevaladd(&atv, &rtv); } else atv.tv_sec = 0; timo = 0; retry: ncoll = nselcoll; p->p_flag |= P_SELECT; error = selscan(p, ibits, obits, uap->nd); if (error || p->p_retval[0]) goto done; if (atv.tv_sec) { getmicrouptime(&rtv); if (timevalcmp(&rtv, &atv, >=)) goto done; ttv = atv; timevalsub(&ttv, &rtv); timo = ttv.tv_sec > 24 * 60 * 60 ? 24 * 60 * 60 * hz : tvtohz(&ttv); } 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 (uap->name && (error2 = copyout(obits[x], uap->name, ncpbytes))) \ error = error2; if (error == 0) { int error2; putbits(in, 0); putbits(ou, 1); putbits(ex, 2); #undef putbits } if (selbits != &s_selbits[0]) free(selbits, M_SELECT); return (error); } static int selscan(p, ibits, obits, nfd) struct proc *p; fd_mask **ibits, **obits; int nfd; { struct filedesc *fdp = p->p_fd; int msk, i, fd; fd_mask bits; struct file *fp; int n = 0; /* Note: backend also returns POLLHUP/POLLERR if appropriate. */ static int flag[3] = { POLLRDNORM, POLLWRNORM, POLLRDBAND }; for (msk = 0; msk < 3; msk++) { if (ibits[msk] == NULL) continue; for (i = 0; i < nfd; i += NFDBITS) { bits = ibits[msk][i/NFDBITS]; /* ffs(int mask) not portable, fd_mask is long */ for (fd = i; bits && fd < nfd; fd++, bits >>= 1) { if (!(bits & 1)) continue; fp = fdp->fd_ofiles[fd]; if (fp == NULL) return (EBADF); if (fo_poll(fp, flag[msk], fp->f_cred, p)) { obits[msk][(fd)/NFDBITS] |= ((fd_mask)1 << ((fd) % NFDBITS)); n++; } } } } p->p_retval[0] = n; return (0); } /* * Poll system call. */ #ifndef _SYS_SYSPROTO_H_ struct poll_args { struct pollfd *fds; u_int nfds; int timeout; }; #endif int poll(p, uap) register struct proc *p; register struct poll_args *uap; { caddr_t bits; char smallbits[32 * sizeof(struct pollfd)]; struct timeval atv, rtv, ttv; int s, ncoll, error = 0, timo; size_t ni; if (SCARG(uap, nfds) > p->p_fd->fd_nfiles) { /* forgiving; slightly wrong */ SCARG(uap, nfds) = p->p_fd->fd_nfiles; } ni = SCARG(uap, nfds) * sizeof(struct pollfd); if (ni > sizeof(smallbits)) bits = malloc(ni, M_TEMP, M_WAITOK); else bits = smallbits; error = copyin(SCARG(uap, fds), bits, ni); if (error) goto done; if (SCARG(uap, timeout) != INFTIM) { atv.tv_sec = SCARG(uap, timeout) / 1000; atv.tv_usec = (SCARG(uap, timeout) % 1000) * 1000; if (itimerfix(&atv)) { error = EINVAL; goto done; } getmicrouptime(&rtv); timevaladd(&atv, &rtv); } else atv.tv_sec = 0; timo = 0; retry: ncoll = nselcoll; p->p_flag |= P_SELECT; error = pollscan(p, (struct pollfd *)bits, SCARG(uap, nfds)); if (error || p->p_retval[0]) goto done; if (atv.tv_sec) { getmicrouptime(&rtv); if (timevalcmp(&rtv, &atv, >=)) goto done; ttv = atv; timevalsub(&ttv, &rtv); timo = ttv.tv_sec > 24 * 60 * 60 ? 24 * 60 * 60 * hz : tvtohz(&ttv); } 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 (error == 0) { error = copyout(bits, SCARG(uap, fds), ni); if (error) goto out; } out: if (ni > sizeof(smallbits)) free(bits, M_TEMP); return (error); } static int pollscan(p, fds, nfd) struct proc *p; struct pollfd *fds; int nfd; { register struct filedesc *fdp = p->p_fd; int i; struct file *fp; int n = 0; for (i = 0; i < nfd; i++, fds++) { if (fds->fd >= fdp->fd_nfiles) { fds->revents = POLLNVAL; n++; } else if (fds->fd < 0) { fds->revents = 0; } else { fp = fdp->fd_ofiles[fds->fd]; if (fp == 0) { fds->revents = POLLNVAL; n++; } else { /* * Note: backend also returns POLLHUP and * POLLERR if appropriate. */ fds->revents = fo_poll(fp, fds->events, fp->f_cred, p); if (fds->revents != 0) n++; } } } p->p_retval[0] = n; return (0); } /* * OpenBSD poll system call. * XXX this isn't quite a true representation.. OpenBSD uses select ops. */ #ifndef _SYS_SYSPROTO_H_ struct openbsd_poll_args { struct pollfd *fds; u_int nfds; int timeout; }; #endif int openbsd_poll(p, uap) register struct proc *p; register struct openbsd_poll_args *uap; { return (poll(p, (struct poll_args *)uap)); } /*ARGSUSED*/ int seltrue(dev, events, p) dev_t dev; int events; struct proc *p; { return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); } /* * 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_pid == mypid) return; if (sip->si_pid && (p = pfind(sip->si_pid)) && p->p_wchan == (caddr_t)&selwait) sip->si_flags |= SI_COLL; else sip->si_pid = 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_pid == 0) return; if (sip->si_flags & SI_COLL) { nselcoll++; sip->si_flags &= ~SI_COLL; wakeup((caddr_t)&selwait); } p = pfind(sip->si_pid); sip->si_pid = 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); } }