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NetBSD/sys/kern/sys_generic.c

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/* $NetBSD: sys_generic.c,v 1.69 2003/01/18 10:06:33 thorpej Exp $ */
/*
* 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 8.9 (Berkeley) 2/14/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sys_generic.c,v 1.69 2003/01/18 10:06:33 thorpej Exp $");
#include "opt_ktrace.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/filedesc.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <sys/proc.h>
#include <sys/socketvar.h>
#include <sys/signalvar.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/stat.h>
#include <sys/malloc.h>
#include <sys/poll.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <sys/mount.h>
#include <sys/sa.h>
#include <sys/syscallargs.h>
int selscan __P((struct proc *, fd_mask *, fd_mask *, int, register_t *));
int pollscan __P((struct proc *, struct pollfd *, int, register_t *));
/*
* Read system call.
*/
/* ARGSUSED */
int
sys_read(struct lwp *l, void *v, register_t *retval)
{
struct sys_read_args /* {
syscallarg(int) fd;
syscallarg(void *) buf;
syscallarg(size_t) nbyte;
} */ *uap = v;
int fd;
struct file *fp;
struct proc *p;
struct filedesc *fdp;
fd = SCARG(uap, fd);
p = l->l_proc;
fdp = p->p_fd;
if ((fp = fd_getfile(fdp, fd)) == NULL)
return (EBADF);
if ((fp->f_flag & FREAD) == 0)
return (EBADF);
FILE_USE(fp);
/* dofileread() will unuse the descriptor for us */
return (dofileread(p, fd, fp, SCARG(uap, buf), SCARG(uap, nbyte),
&fp->f_offset, FOF_UPDATE_OFFSET, retval));
}
int
dofileread(struct proc *p, int fd, struct file *fp, void *buf, size_t nbyte,
off_t *offset, int flags, register_t *retval)
{
struct uio auio;
struct iovec aiov;
size_t cnt;
int error;
#ifdef KTRACE
struct iovec ktriov;
#endif
error = 0;
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, flags);
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:
FILE_UNUSE(fp, p);
return (error);
}
/*
* Scatter read system call.
*/
int
sys_readv(struct lwp *l, void *v, register_t *retval)
{
struct sys_readv_args /* {
syscallarg(int) fd;
syscallarg(const struct iovec *) iovp;
syscallarg(int) iovcnt;
} */ *uap = v;
int fd;
struct file *fp;
struct proc *p;
struct filedesc *fdp;
fd = SCARG(uap, fd);
p = l->l_proc;
fdp = p->p_fd;
if ((fp = fd_getfile(fdp, fd)) == NULL)
return (EBADF);
if ((fp->f_flag & FREAD) == 0)
return (EBADF);
FILE_USE(fp);
/* dofilereadv() will unuse the descriptor for us */
return (dofilereadv(p, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt),
&fp->f_offset, FOF_UPDATE_OFFSET, retval));
}
int
dofilereadv(struct proc *p, int fd, struct file *fp, const struct iovec *iovp,
int iovcnt, off_t *offset, int flags, register_t *retval)
{
struct uio auio;
struct iovec *iov, *needfree, aiov[UIO_SMALLIOV];
int i, error;
size_t cnt;
u_int iovlen;
#ifdef KTRACE
struct iovec *ktriov;
#endif
error = 0;
#ifdef KTRACE
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 = malloc(iovlen, M_IOV, M_WAITOK);
needfree = iov;
} 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);
memcpy((caddr_t)ktriov, (caddr_t)auio.uio_iov, iovlen);
}
#endif
cnt = auio.uio_resid;
error = (*fp->f_ops->fo_read)(fp, offset, &auio, fp->f_cred, flags);
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:
FILE_UNUSE(fp, p);
return (error);
}
/*
* Write system call
*/
int
sys_write(struct lwp *l, void *v, register_t *retval)
{
struct sys_write_args /* {
syscallarg(int) fd;
syscallarg(const void *) buf;
syscallarg(size_t) nbyte;
} */ *uap = v;
int fd;
struct file *fp;
struct proc *p;
struct filedesc *fdp;
fd = SCARG(uap, fd);
p = l->l_proc;
fdp = p->p_fd;
if ((fp = fd_getfile(fdp, fd)) == NULL)
return (EBADF);
if ((fp->f_flag & FWRITE) == 0)
return (EBADF);
FILE_USE(fp);
/* dofilewrite() will unuse the descriptor for us */
return (dofilewrite(p, fd, fp, SCARG(uap, buf), SCARG(uap, nbyte),
&fp->f_offset, FOF_UPDATE_OFFSET, retval));
}
int
dofilewrite(struct proc *p, int fd, struct file *fp, const void *buf,
size_t nbyte, off_t *offset, int flags, register_t *retval)
{
struct uio auio;
struct iovec aiov;
size_t cnt;
int error;
#ifdef KTRACE
struct iovec ktriov;
#endif
error = 0;
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, flags);
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:
FILE_UNUSE(fp, p);
return (error);
}
/*
* Gather write system call
*/
int
sys_writev(struct lwp *l, void *v, register_t *retval)
{
struct sys_writev_args /* {
syscallarg(int) fd;
syscallarg(const struct iovec *) iovp;
syscallarg(int) iovcnt;
} */ *uap = v;
int fd;
struct file *fp;
struct proc *p;
struct filedesc *fdp;
fd = SCARG(uap, fd);
p = l->l_proc;
fdp = p->p_fd;
if ((fp = fd_getfile(fdp, fd)) == NULL)
return (EBADF);
if ((fp->f_flag & FWRITE) == 0)
return (EBADF);
FILE_USE(fp);
/* dofilewritev() will unuse the descriptor for us */
return (dofilewritev(p, fd, fp, SCARG(uap, iovp), SCARG(uap, iovcnt),
&fp->f_offset, FOF_UPDATE_OFFSET, retval));
}
int
dofilewritev(struct proc *p, int fd, struct file *fp, const struct iovec *iovp,
int iovcnt, off_t *offset, int flags, register_t *retval)
{
struct uio auio;
struct iovec *iov, *needfree, aiov[UIO_SMALLIOV];
int i, error;
size_t cnt;
u_int iovlen;
#ifdef KTRACE
struct iovec *ktriov;
#endif
error = 0;
#ifdef KTRACE
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 = malloc(iovlen, M_IOV, M_WAITOK);
needfree = iov;
} 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);
memcpy((caddr_t)ktriov, (caddr_t)auio.uio_iov, iovlen);
}
#endif
cnt = auio.uio_resid;
error = (*fp->f_ops->fo_write)(fp, offset, &auio, fp->f_cred, flags);
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))
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:
FILE_UNUSE(fp, p);
return (error);
}
/*
* Ioctl system call
*/
/* ARGSUSED */
int
sys_ioctl(struct lwp *l, void *v, register_t *retval)
{
struct sys_ioctl_args /* {
syscallarg(int) fd;
syscallarg(u_long) com;
syscallarg(caddr_t) data;
} */ *uap = v;
struct file *fp;
struct proc *p;
struct filedesc *fdp;
u_long com;
int error;
u_int size;
caddr_t data, memp;
int tmp;
#define STK_PARAMS 128
u_long stkbuf[STK_PARAMS/sizeof(u_long)];
error = 0;
p = l->l_proc;
fdp = p->p_fd;
if ((fp = fd_getfile(fdp, SCARG(uap, fd))) == NULL)
return (EBADF);
FILE_USE(fp);
if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
error = EBADF;
com = 0;
goto out;
}
switch (com = SCARG(uap, com)) {
case FIONCLEX:
fdp->fd_ofileflags[SCARG(uap, fd)] &= ~UF_EXCLOSE;
goto out;
case FIOCLEX:
fdp->fd_ofileflags[SCARG(uap, fd)] |= UF_EXCLOSE;
goto out;
}
/*
* 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) {
error = ENOTTY;
goto out;
}
memp = NULL;
if (size > sizeof(stkbuf)) {
memp = (caddr_t)malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
data = memp;
} else
data = (caddr_t)stkbuf;
if (com&IOC_IN) {
if (size) {
error = copyin(SCARG(uap, data), data, size);
if (error) {
if (memp)
free(memp, M_IOCTLOPS);
goto out;
}
} else
*(caddr_t *)data = SCARG(uap, data);
} else if ((com&IOC_OUT) && size)
/*
* Zero the buffer so the user always
* gets back something deterministic.
*/
memset(data, 0, 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 *)fp->f_data)->so_pgid = tmp;
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);
if (error == 0)
*(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), size);
break;
}
if (memp)
free(memp, M_IOCTLOPS);
out:
FILE_UNUSE(fp, p);
switch (error) {
case -1:
printf("sys_ioctl: _IO%s%s('%c', %lu, %lu) returned -1: "
"pid=%d comm=%s\n",
(com & IOC_IN) ? "W" : "", (com & IOC_OUT) ? "R" : "",
(char)IOCGROUP(com), (com & 0xff), IOCPARM_LEN(com),
p->p_pid, p->p_comm);
/* FALLTHROUGH */
case EPASSTHROUGH:
error = ENOTTY;
/* FALLTHROUGH */
default:
return (error);
}
}
int selwait, nselcoll;
/*
* Select system call.
*/
int
sys_select(struct lwp *l, void *v, register_t *retval)
{
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;
struct proc *p;
caddr_t bits;
char smallbits[howmany(FD_SETSIZE, NFDBITS) *
sizeof(fd_mask) * 6];
struct timeval atv;
int s, ncoll, error, timo;
size_t ni;
error = 0;
p = l->l_proc;
if (SCARG(uap, nd) < 0)
return (EINVAL);
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 (ni * 6 > sizeof(smallbits))
bits = malloc(ni * 6, M_TEMP, M_WAITOK);
else
bits = smallbits;
#define getbits(name, x) \
if (SCARG(uap, name)) { \
error = copyin(SCARG(uap, name), bits + ni * x, ni); \
if (error) \
goto done; \
} else \
memset(bits + ni * x, 0, ni);
getbits(in, 0);
getbits(ou, 1);
getbits(ex, 2);
#undef getbits
timo = 0;
if (SCARG(uap, tv)) {
error = copyin(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);
}
retry:
ncoll = nselcoll;
l->l_flag |= L_SELECT;
error = selscan(p, (fd_mask *)(bits + ni * 0),
(fd_mask *)(bits + ni * 3), 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 = splsched();
if ((l->l_flag & L_SELECT) == 0 || nselcoll != ncoll) {
splx(s);
goto retry;
}
l->l_flag &= ~L_SELECT;
error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo);
splx(s);
if (error == 0)
goto retry;
done:
l->l_flag &= ~L_SELECT;
/* select is not restarted after signals... */
if (error == ERESTART)
error = EINTR;
if (error == EWOULDBLOCK)
error = 0;
if (error == 0) {
#define putbits(name, x) \
if (SCARG(uap, name)) { \
error = copyout(bits + ni * x, SCARG(uap, name), ni); \
if (error) \
goto out; \
}
putbits(in, 3);
putbits(ou, 4);
putbits(ex, 5);
#undef putbits
}
out:
if (ni * 6 > sizeof(smallbits))
free(bits, M_TEMP);
return (error);
}
int
selscan(struct proc *p, fd_mask *ibitp, fd_mask *obitp, int nfd,
register_t *retval)
{
struct filedesc *fdp;
int msk, i, j, fd, n;
fd_mask ibits, obits;
struct file *fp;
static const int flag[3] = { POLLRDNORM | POLLHUP | POLLERR,
POLLWRNORM | POLLHUP | POLLERR,
POLLRDBAND };
fdp = p->p_fd;
n = 0;
for (msk = 0; msk < 3; msk++) {
for (i = 0; i < nfd; i += NFDBITS) {
ibits = *ibitp++;
obits = 0;
while ((j = ffs(ibits)) && (fd = i + --j) < nfd) {
ibits &= ~(1 << j);
if ((fp = fd_getfile(fdp, fd)) == NULL)
return (EBADF);
FILE_USE(fp);
if ((*fp->f_ops->fo_poll)(fp, flag[msk], p)) {
obits |= (1 << j);
n++;
}
FILE_UNUSE(fp, p);
}
*obitp++ = obits;
}
}
*retval = n;
return (0);
}
/*
* Poll system call.
*/
int
sys_poll(struct lwp *l, void *v, register_t *retval)
{
struct sys_poll_args /* {
syscallarg(struct pollfd *) fds;
syscallarg(u_int) nfds;
syscallarg(int) timeout;
} */ *uap = v;
struct proc *p;
caddr_t bits;
char smallbits[32 * sizeof(struct pollfd)];
struct timeval atv;
int s, ncoll, error, timo;
size_t ni;
error = 0;
p = l->l_proc;
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;
timo = 0;
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;
}
s = splclock();
timeradd(&atv, &time, &atv);
splx(s);
}
retry:
ncoll = nselcoll;
l->l_flag |= L_SELECT;
error = pollscan(p, (struct pollfd *)bits, SCARG(uap, nfds), retval);
if (error || *retval)
goto done;
if (SCARG(uap, timeout) != INFTIM) {
/*
* We have to recalculate the timeout on every retry.
*/
timo = hzto(&atv);
if (timo <= 0)
goto done;
}
s = splsched();
if ((l->l_flag & L_SELECT) == 0 || nselcoll != ncoll) {
splx(s);
goto retry;
}
l->l_flag &= ~L_SELECT;
error = tsleep((caddr_t)&selwait, PSOCK | PCATCH, "select", timo);
splx(s);
if (error == 0)
goto retry;
done:
l->l_flag &= ~L_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);
}
int
pollscan(struct proc *p, struct pollfd *fds, int nfd, register_t *retval)
{
struct filedesc *fdp;
int i, n;
struct file *fp;
fdp = p->p_fd;
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 {
if ((fp = fd_getfile(fdp, fds->fd)) == NULL) {
fds->revents = POLLNVAL;
n++;
} else {
FILE_USE(fp);
fds->revents = (*fp->f_ops->fo_poll)(fp,
fds->events | POLLERR | POLLHUP, p);
if (fds->revents != 0)
n++;
FILE_UNUSE(fp, p);
}
}
}
*retval = n;
return (0);
}
/*ARGSUSED*/
int
seltrue(dev_t dev, int events, struct proc *p)
{
return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
}
/*
* Record a select request.
*/
void
selrecord(struct proc *selector, struct selinfo *sip)
{
struct lwp *l;
struct proc *p;
pid_t mypid;
int collision;
mypid = selector->p_pid;
if (sip->sel_pid == mypid)
return;
collision = 0;
if (sip->sel_pid && (p = pfind(sip->sel_pid))) {
for (l = LIST_FIRST(&p->p_lwps); l != NULL;
l = LIST_NEXT(l, l_sibling)) {
if (l->l_wchan == (caddr_t)&selwait) {
collision = 1;
sip->sel_flags |= SI_COLL;
}
}
}
if (collision == 0)
sip->sel_pid = mypid;
}
/*
* Do a wakeup when a selectable event occurs.
*/
void
selwakeup(sip)
struct selinfo *sip;
{
struct lwp *l;
struct proc *p;
int s;
if (sip->sel_pid == 0)
return;
if (sip->sel_flags & SI_COLL) {
sip->sel_pid = 0;
nselcoll++;
sip->sel_flags &= ~SI_COLL;
wakeup((caddr_t)&selwait);
return;
}
p = pfind(sip->sel_pid);
sip->sel_pid = 0;
if (p != NULL) {
for (l = LIST_FIRST(&p->p_lwps); l != NULL;
l = LIST_NEXT(l, l_sibling)) {
SCHED_LOCK(s);
if (l->l_wchan == (caddr_t)&selwait) {
if (l->l_stat == LSSLEEP)
setrunnable(l);
else
unsleep(l);
} else if (l->l_flag & L_SELECT)
l->l_flag &= ~L_SELECT;
SCHED_UNLOCK(s);
}
}
}
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