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freebsd-skq/sys/kern/sys_generic.c
green 140cb4ff83 This is what was "fdfix2.patch," a fix for fd sharing. It's pretty 
far-reaching in fd-land, so you'll want to consult the code for
changes.  The biggest change is that now, you don't use
	fp->f_ops->fo_foo(fp, bar)
but instead
	fo_foo(fp, bar),
which increments and decrements the fp refcount upon entry and exit.
Two new calls, fhold() and fdrop(), are provided.  Each does what it
seems like it should, and if fdrop() brings the refcount to zero, the
fd is freed as well.

Thanks to peter ("to hell with it, it looks ok to me.") for his review.
Thanks to msmith for keeping me from putting locks everywhere :)

Reviewed by:	peter
1999-09-19 17:00:25 +00:00

963 lines
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/*
* 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/filedesc.h>
#include <sys/filio.h>
#include <sys/ttycom.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/socketvar.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/poll.h>
#include <sys/sysent.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <machine/limits.h>
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 struct file* getfp __P((struct filedesc *, int, 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));
static 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);
/* 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_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:
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
char stkbuf[STK_PARAMS];
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 (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(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;
int selwait;
/*
* 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;
{
register struct filedesc *fdp = p->p_fd;
register int msk, i, j, fd;
register 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];
while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
bits &= ~(1 << j);
fp = fdp->fd_ofiles[fd];
if (fp == NULL)
return (EBADF);
if (fo_poll(fp, flag[msk], fp->f_cred, p)) {
obits[msk][(fd)/NFDBITS] |=
(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);
}
}
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