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NetBSD/sys/kern/sys_generic.c

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/* $NetBSD: sys_generic.c,v 1.108 2007/10/08 15:12:08 ad Exp $ */
/*-
* Copyright (c) 2007 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Doran.
*
* 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 NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* 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. 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
*/
/*
* System calls relating to files.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sys_generic.c,v 1.108 2007/10/08 15:12:08 ad Exp $");
#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/kmem.h>
#include <sys/poll.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
#include <sys/ktrace.h>
#include <uvm/uvm_extern.h>
/* Flags for lwp::l_selflag. */
#define SEL_RESET 0 /* awoken, interrupted, or not yet polling */
#define SEL_SCANNING 1 /* polling descriptors */
#define SEL_BLOCKING 2 /* about to block on select_cv */
static int selscan(lwp_t *, fd_mask *, fd_mask *, int, register_t *);
static int pollscan(lwp_t *, struct pollfd *, int, register_t *);
static void selclear(void);
/* Global state for select()/poll(). */
kmutex_t select_lock;
kcondvar_t select_cv;
int nselcoll;
/*
* Read system call.
*/
/* ARGSUSED */
int
sys_read(lwp_t *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;
proc_t *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) {
mutex_exit(&fp->f_lock);
return (EBADF);
}
FILE_USE(fp);
/* dofileread() will unuse the descriptor for us */
return (dofileread(fd, fp, SCARG(uap, buf), SCARG(uap, nbyte),
&fp->f_offset, FOF_UPDATE_OFFSET, retval));
}
int
dofileread(int fd, struct file *fp, void *buf, size_t nbyte,
off_t *offset, int flags, register_t *retval)
{
struct iovec aiov;
struct uio auio;
size_t cnt;
int error;
lwp_t *l;
l = curlwp;
aiov.iov_base = (void *)buf;
aiov.iov_len = nbyte;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_resid = nbyte;
auio.uio_rw = UIO_READ;
auio.uio_vmspace = l->l_proc->p_vmspace;
/*
* 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;
}
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;
ktrgenio(fd, UIO_READ, buf, cnt, error);
*retval = cnt;
out:
FILE_UNUSE(fp, l);
return (error);
}
/*
* Scatter read system call.
*/
int
sys_readv(lwp_t *l, void *v, register_t *retval)
{
struct sys_readv_args /* {
syscallarg(int) fd;
syscallarg(const struct iovec *) iovp;
syscallarg(int) iovcnt;
} */ *uap = v;
return do_filereadv(SCARG(uap, fd), SCARG(uap, iovp),
SCARG(uap, iovcnt), NULL, FOF_UPDATE_OFFSET, retval);
}
int
do_filereadv(int fd, const struct iovec *iovp, int iovcnt,
off_t *offset, int flags, register_t *retval)
{
struct uio auio;
struct iovec *iov, *needfree = NULL, aiov[UIO_SMALLIOV];
int i, error;
size_t cnt;
u_int iovlen;
struct file *fp;
struct iovec *ktriov = NULL;
lwp_t *l;
if (iovcnt == 0)
return EINVAL;
l = curlwp;
if ((fp = fd_getfile(l->l_proc->p_fd, fd)) == NULL)
return EBADF;
if ((fp->f_flag & FREAD) == 0) {
mutex_exit(&fp->f_lock);
return EBADF;
}
FILE_USE(fp);
if (offset == NULL)
offset = &fp->f_offset;
else {
struct vnode *vp = fp->f_data;
if (fp->f_type != DTYPE_VNODE || vp->v_type == VFIFO) {
error = ESPIPE;
goto out;
}
/*
* Test that the device is seekable ?
* XXX This works because no file systems actually
* XXX take any action on the seek operation.
*/
error = VOP_SEEK(vp, fp->f_offset, *offset, fp->f_cred);
if (error != 0)
goto out;
}
iovlen = iovcnt * sizeof(struct iovec);
if (flags & FOF_IOV_SYSSPACE)
iov = __UNCONST(iovp);
else {
iov = aiov;
if ((u_int)iovcnt > UIO_SMALLIOV) {
if ((u_int)iovcnt > IOV_MAX) {
error = EINVAL;
goto out;
}
iov = kmem_alloc(iovlen, KM_SLEEP);
if (iov == NULL) {
error = ENOMEM;
goto out;
}
needfree = iov;
}
error = copyin(iovp, iov, iovlen);
if (error)
goto done;
}
auio.uio_iov = iov;
auio.uio_iovcnt = iovcnt;
auio.uio_rw = UIO_READ;
auio.uio_vmspace = l->l_proc->p_vmspace;
auio.uio_resid = 0;
for (i = 0; i < iovcnt; i++, iov++) {
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;
}
}
/*
* if tracing, save a copy of iovec
*/
if (ktrpoint(KTR_GENIO)) {
ktriov = kmem_alloc(iovlen, KM_SLEEP);
if (ktriov != NULL)
memcpy(ktriov, auio.uio_iov, iovlen);
}
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;
*retval = cnt;
if (ktriov != NULL) {
ktrgeniov(fd, UIO_READ, ktriov, cnt, error);
kmem_free(ktriov, iovlen);
}
done:
if (needfree)
kmem_free(needfree, iovlen);
out:
FILE_UNUSE(fp, l);
return (error);
}
/*
* Write system call
*/
int
sys_write(lwp_t *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;
fd = SCARG(uap, fd);
if ((fp = fd_getfile(curproc->p_fd, fd)) == NULL)
return (EBADF);
if ((fp->f_flag & FWRITE) == 0) {
mutex_exit(&fp->f_lock);
return (EBADF);
}
FILE_USE(fp);
/* dofilewrite() will unuse the descriptor for us */
return (dofilewrite(fd, fp, SCARG(uap, buf), SCARG(uap, nbyte),
&fp->f_offset, FOF_UPDATE_OFFSET, retval));
}
int
dofilewrite(int fd, struct file *fp, const void *buf,
size_t nbyte, off_t *offset, int flags, register_t *retval)
{
struct iovec aiov;
struct uio auio;
size_t cnt;
int error;
lwp_t *l;
l = curlwp;
aiov.iov_base = __UNCONST(buf); /* XXXUNCONST 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_vmspace = l->l_proc->p_vmspace;
/*
* 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;
}
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) {
mutex_enter(&proclist_mutex);
psignal(l->l_proc, SIGPIPE);
mutex_exit(&proclist_mutex);
}
}
cnt -= auio.uio_resid;
ktrgenio(fd, UIO_WRITE, buf, cnt, error);
*retval = cnt;
out:
FILE_UNUSE(fp, l);
return (error);
}
/*
* Gather write system call
*/
int
sys_writev(lwp_t *l, void *v, register_t *retval)
{
struct sys_writev_args /* {
syscallarg(int) fd;
syscallarg(const struct iovec *) iovp;
syscallarg(int) iovcnt;
} */ *uap = v;
return do_filewritev(SCARG(uap, fd), SCARG(uap, iovp),
SCARG(uap, iovcnt), NULL, FOF_UPDATE_OFFSET, retval);
}
int
do_filewritev(int fd, const struct iovec *iovp, int iovcnt,
off_t *offset, int flags, register_t *retval)
{
struct uio auio;
struct iovec *iov, *needfree = NULL, aiov[UIO_SMALLIOV];
int i, error;
size_t cnt;
u_int iovlen;
struct file *fp;
struct iovec *ktriov = NULL;
lwp_t *l;
l = curlwp;
if (iovcnt == 0)
return EINVAL;
if ((fp = fd_getfile(l->l_proc->p_fd, fd)) == NULL)
return EBADF;
if ((fp->f_flag & FWRITE) == 0) {
mutex_exit(&fp->f_lock);
return EBADF;
}
FILE_USE(fp);
if (offset == NULL)
offset = &fp->f_offset;
else {
struct vnode *vp = fp->f_data;
if (fp->f_type != DTYPE_VNODE || vp->v_type == VFIFO) {
error = ESPIPE;
goto out;
}
/*
* Test that the device is seekable ?
* XXX This works because no file systems actually
* XXX take any action on the seek operation.
*/
error = VOP_SEEK(vp, fp->f_offset, *offset, fp->f_cred);
if (error != 0)
goto out;
}
iovlen = iovcnt * sizeof(struct iovec);
if (flags & FOF_IOV_SYSSPACE)
iov = __UNCONST(iovp);
else {
iov = aiov;
if ((u_int)iovcnt > UIO_SMALLIOV) {
if ((u_int)iovcnt > IOV_MAX) {
error = EINVAL;
goto out;
}
iov = kmem_alloc(iovlen, KM_SLEEP);
if (iov == NULL) {
error = ENOMEM;
goto out;
}
needfree = iov;
}
error = copyin(iovp, iov, iovlen);
if (error)
goto done;
}
auio.uio_iov = iov;
auio.uio_iovcnt = iovcnt;
auio.uio_rw = UIO_WRITE;
auio.uio_vmspace = curproc->p_vmspace;
auio.uio_resid = 0;
for (i = 0; i < iovcnt; i++, iov++) {
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;
}
}
/*
* if tracing, save a copy of iovec
*/
if (ktrpoint(KTR_GENIO)) {
ktriov = kmem_alloc(iovlen, KM_SLEEP);
if (ktriov != NULL)
memcpy(ktriov, auio.uio_iov, iovlen);
}
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) {
mutex_enter(&proclist_mutex);
psignal(l->l_proc, SIGPIPE);
mutex_exit(&proclist_mutex);
}
}
cnt -= auio.uio_resid;
*retval = cnt;
if (ktriov != NULL) {
ktrgeniov(fd, UIO_WRITE, ktriov, cnt, error);
kmem_free(ktriov, iovlen);
}
done:
if (needfree)
kmem_free(needfree, iovlen);
out:
FILE_UNUSE(fp, l);
return (error);
}
/*
* Ioctl system call
*/
/* ARGSUSED */
int
sys_ioctl(lwp_t *l, void *v, register_t *retval)
{
struct sys_ioctl_args /* {
syscallarg(int) fd;
syscallarg(u_long) com;
syscallarg(void *) data;
} */ *uap = v;
struct file *fp;
proc_t *p;
struct filedesc *fdp;
u_long com;
int error;
u_int size;
void *data, *memp;
#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:
rw_enter(&fdp->fd_lock, RW_WRITER);
fdp->fd_ofileflags[SCARG(uap, fd)] &= ~UF_EXCLOSE;
rw_exit(&fdp->fd_lock);
goto out;
case FIOCLEX:
rw_enter(&fdp->fd_lock, RW_WRITER);
fdp->fd_ofileflags[SCARG(uap, fd)] |= UF_EXCLOSE;
rw_exit(&fdp->fd_lock);
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 = kmem_alloc(size, KM_SLEEP);
data = memp;
} else
data = (void *)stkbuf;
if (com&IOC_IN) {
if (size) {
error = copyin(SCARG(uap, data), data, size);
if (error) {
if (memp)
kmem_free(memp, size);
goto out;
}
ktrgenio(SCARG(uap, fd), UIO_WRITE, SCARG(uap, data),
size, 0);
} else
*(void **)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)
*(void **)data = SCARG(uap, data);
switch (com) {
case FIONBIO:
mutex_enter(&fp->f_lock);
if (*(int *)data != 0)
fp->f_flag |= FNONBLOCK;
else
fp->f_flag &= ~FNONBLOCK;
mutex_exit(&fp->f_lock);
error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, data, l);
break;
case FIOASYNC:
mutex_enter(&fp->f_lock);
if (*(int *)data != 0)
fp->f_flag |= FASYNC;
else
fp->f_flag &= ~FASYNC;
mutex_exit(&fp->f_lock);
error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, data, l);
break;
default:
error = (*fp->f_ops->fo_ioctl)(fp, com, data, l);
/*
* 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);
ktrgenio(SCARG(uap, fd), UIO_READ, SCARG(uap, data),
size, error);
}
break;
}
if (memp)
kmem_free(memp, size);
out:
FILE_UNUSE(fp, l);
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);
}
}
/*
* Select system call.
*/
int
sys_pselect(lwp_t *l, void *v, register_t *retval)
{
struct sys_pselect_args /* {
syscallarg(int) nd;
syscallarg(fd_set *) in;
syscallarg(fd_set *) ou;
syscallarg(fd_set *) ex;
syscallarg(const struct timespec *) ts;
syscallarg(sigset_t *) mask;
} */ * const uap = v;
struct timespec ats;
struct timeval atv, *tv = NULL;
sigset_t amask, *mask = NULL;
int error;
if (SCARG(uap, ts)) {
error = copyin(SCARG(uap, ts), &ats, sizeof(ats));
if (error)
return error;
atv.tv_sec = ats.tv_sec;
atv.tv_usec = ats.tv_nsec / 1000;
tv = &atv;
}
if (SCARG(uap, mask) != NULL) {
error = copyin(SCARG(uap, mask), &amask, sizeof(amask));
if (error)
return error;
mask = &amask;
}
return selcommon(l, retval, SCARG(uap, nd), SCARG(uap, in),
SCARG(uap, ou), SCARG(uap, ex), tv, mask);
}
int
inittimeleft(struct timeval *tv, struct timeval *sleeptv)
{
if (itimerfix(tv))
return -1;
getmicrouptime(sleeptv);
return 0;
}
int
gettimeleft(struct timeval *tv, struct timeval *sleeptv)
{
/*
* We have to recalculate the timeout on every retry.
*/
struct timeval slepttv;
/*
* reduce tv by elapsed time
* based on monotonic time scale
*/
getmicrouptime(&slepttv);
timeradd(tv, sleeptv, tv);
timersub(tv, &slepttv, tv);
*sleeptv = slepttv;
return tvtohz(tv);
}
int
sys_select(lwp_t *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;
} */ * const uap = v;
struct timeval atv, *tv = NULL;
int error;
if (SCARG(uap, tv)) {
error = copyin(SCARG(uap, tv), (void *)&atv,
sizeof(atv));
if (error)
return error;
tv = &atv;
}
return selcommon(l, retval, SCARG(uap, nd), SCARG(uap, in),
SCARG(uap, ou), SCARG(uap, ex), tv, NULL);
}
int
selcommon(lwp_t *l, register_t *retval, int nd, fd_set *u_in,
fd_set *u_ou, fd_set *u_ex, struct timeval *tv, sigset_t *mask)
{
char smallbits[howmany(FD_SETSIZE, NFDBITS) *
sizeof(fd_mask) * 6];
proc_t * const p = l->l_proc;
char *bits;
int ncoll, error, timo;
size_t ni;
sigset_t oldmask;
struct timeval sleeptv;
error = 0;
if (nd < 0)
return (EINVAL);
if (nd > p->p_fd->fd_nfiles) {
/* forgiving; slightly wrong */
nd = p->p_fd->fd_nfiles;
}
ni = howmany(nd, NFDBITS) * sizeof(fd_mask);
if (ni * 6 > sizeof(smallbits))
bits = kmem_alloc(ni * 6, KM_SLEEP);
else
bits = smallbits;
#define getbits(name, x) \
if (u_ ## name) { \
error = copyin(u_ ## 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 (tv && inittimeleft(tv, &sleeptv) == -1) {
error = EINVAL;
goto done;
}
if (mask) {
sigminusset(&sigcantmask, mask);
mutex_enter(&p->p_smutex);
oldmask = l->l_sigmask;
l->l_sigmask = *mask;
mutex_exit(&p->p_smutex);
} else
oldmask = l->l_sigmask; /* XXXgcc */
mutex_enter(&select_lock);
SLIST_INIT(&l->l_selwait);
for (;;) {
l->l_selflag = SEL_SCANNING;
ncoll = nselcoll;
mutex_exit(&select_lock);
error = selscan(l, (fd_mask *)(bits + ni * 0),
(fd_mask *)(bits + ni * 3), nd, retval);
mutex_enter(&select_lock);
if (error || *retval)
break;
if (tv && (timo = gettimeleft(tv, &sleeptv)) <= 0)
break;
if (l->l_selflag != SEL_SCANNING || ncoll != nselcoll)
continue;
l->l_selflag = SEL_BLOCKING;
error = cv_timedwait_sig(&select_cv, &select_lock, timo);
if (error != 0)
break;
}
selclear();
mutex_exit(&select_lock);
if (mask) {
mutex_enter(&p->p_smutex);
l->l_sigmask = oldmask;
mutex_exit(&p->p_smutex);
}
done:
/* select is not restarted after signals... */
if (error == ERESTART)
error = EINTR;
if (error == EWOULDBLOCK)
error = 0;
if (error == 0 && u_in != NULL)
error = copyout(bits + ni * 3, u_in, ni);
if (error == 0 && u_ou != NULL)
error = copyout(bits + ni * 4, u_ou, ni);
if (error == 0 && u_ex != NULL)
error = copyout(bits + ni * 5, u_ex, ni);
if (bits != smallbits)
kmem_free(bits, ni * 6);
return (error);
}
int
selscan(lwp_t *l, fd_mask *ibitp, fd_mask *obitp, int nfd,
register_t *retval)
{
static const int flag[3] = { POLLRDNORM | POLLHUP | POLLERR,
POLLWRNORM | POLLHUP | POLLERR,
POLLRDBAND };
proc_t *p = l->l_proc;
struct filedesc *fdp;
int msk, i, j, fd, n;
fd_mask ibits, obits;
struct file *fp;
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], l)) {
obits |= (1 << j);
n++;
}
FILE_UNUSE(fp, l);
}
*obitp++ = obits;
}
}
*retval = n;
return (0);
}
/*
* Poll system call.
*/
int
sys_poll(lwp_t *l, void *v, register_t *retval)
{
struct sys_poll_args /* {
syscallarg(struct pollfd *) fds;
syscallarg(u_int) nfds;
syscallarg(int) timeout;
} */ * const uap = v;
struct timeval atv, *tv = NULL;
if (SCARG(uap, timeout) != INFTIM) {
atv.tv_sec = SCARG(uap, timeout) / 1000;
atv.tv_usec = (SCARG(uap, timeout) % 1000) * 1000;
tv = &atv;
}
return pollcommon(l, retval, SCARG(uap, fds), SCARG(uap, nfds),
tv, NULL);
}
/*
* Poll system call.
*/
int
sys_pollts(lwp_t *l, void *v, register_t *retval)
{
struct sys_pollts_args /* {
syscallarg(struct pollfd *) fds;
syscallarg(u_int) nfds;
syscallarg(const struct timespec *) ts;
syscallarg(const sigset_t *) mask;
} */ * const uap = v;
struct timespec ats;
struct timeval atv, *tv = NULL;
sigset_t amask, *mask = NULL;
int error;
if (SCARG(uap, ts)) {
error = copyin(SCARG(uap, ts), &ats, sizeof(ats));
if (error)
return error;
atv.tv_sec = ats.tv_sec;
atv.tv_usec = ats.tv_nsec / 1000;
tv = &atv;
}
if (SCARG(uap, mask)) {
error = copyin(SCARG(uap, mask), &amask, sizeof(amask));
if (error)
return error;
mask = &amask;
}
return pollcommon(l, retval, SCARG(uap, fds), SCARG(uap, nfds),
tv, mask);
}
int
pollcommon(lwp_t *l, register_t *retval,
struct pollfd *u_fds, u_int nfds,
struct timeval *tv, sigset_t *mask)
{
char smallbits[32 * sizeof(struct pollfd)];
proc_t * const p = l->l_proc;
void * bits;
sigset_t oldmask;
int ncoll, error, timo;
size_t ni;
struct timeval sleeptv;
if (nfds > p->p_fd->fd_nfiles) {
/* forgiving; slightly wrong */
nfds = p->p_fd->fd_nfiles;
}
ni = nfds * sizeof(struct pollfd);
if (ni > sizeof(smallbits))
bits = kmem_alloc(ni, KM_SLEEP);
else
bits = smallbits;
error = copyin(u_fds, bits, ni);
if (error)
goto done;
timo = 0;
if (tv && inittimeleft(tv, &sleeptv) == -1) {
error = EINVAL;
goto done;
}
if (mask) {
sigminusset(&sigcantmask, mask);
mutex_enter(&p->p_smutex);
oldmask = l->l_sigmask;
l->l_sigmask = *mask;
mutex_exit(&p->p_smutex);
} else
oldmask = l->l_sigmask; /* XXXgcc */
mutex_enter(&select_lock);
SLIST_INIT(&l->l_selwait);
for (;;) {
ncoll = nselcoll;
l->l_selflag = SEL_SCANNING;
mutex_exit(&select_lock);
error = pollscan(l, (struct pollfd *)bits, nfds, retval);
mutex_enter(&select_lock);
if (error || *retval)
break;
if (tv && (timo = gettimeleft(tv, &sleeptv)) <= 0)
break;
if (l->l_selflag != SEL_SCANNING || nselcoll != ncoll)
continue;
l->l_selflag = SEL_BLOCKING;
error = cv_timedwait_sig(&select_cv, &select_lock, timo);
if (error != 0)
break;
}
selclear();
mutex_exit(&select_lock);
if (mask) {
mutex_enter(&p->p_smutex);
l->l_sigmask = oldmask;
mutex_exit(&p->p_smutex);
}
done:
/* poll is not restarted after signals... */
if (error == ERESTART)
error = EINTR;
if (error == EWOULDBLOCK)
error = 0;
if (error == 0)
error = copyout(bits, u_fds, ni);
if (bits != smallbits)
kmem_free(bits, ni);
return (error);
}
int
pollscan(lwp_t *l, struct pollfd *fds, int nfd, register_t *retval)
{
proc_t *p = l->l_proc;
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, l);
if (fds->revents != 0)
n++;
FILE_UNUSE(fp, l);
}
}
}
*retval = n;
return (0);
}
/*ARGSUSED*/
int
seltrue(dev_t dev, int events, lwp_t *l)
{
return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
}
/*
* Record a select request.
*/
void
selrecord(lwp_t *selector, struct selinfo *sip)
{
mutex_enter(&select_lock);
if (sip->sel_lwp == NULL) {
/* First named waiter, although there may be more. */
sip->sel_lwp = selector;
SLIST_INSERT_HEAD(&selector->l_selwait, sip, sel_chain);
} else if (sip->sel_lwp != selector) {
/* Multiple waiters. */
sip->sel_collision = true;
}
mutex_exit(&select_lock);
}
/*
* Do a wakeup when a selectable event occurs.
*/
void
selwakeup(struct selinfo *sip)
{
lwp_t *l;
mutex_enter(&select_lock);
if (sip->sel_collision) {
/* Multiple waiters - just notify everybody. */
nselcoll++;
sip->sel_collision = false;
cv_broadcast(&select_cv);
} else if (sip->sel_lwp != NULL) {
/* Only one LWP waiting. */
l = sip->sel_lwp;
if (l->l_selflag == SEL_BLOCKING) {
/*
* If it's sleeping, wake it up. If not, it's
* already awake but hasn't yet removed itself
* from the selector. We reset the state below
* so that we only attempt to do this once.
*/
lwp_lock(l);
if (l->l_wchan == &select_cv) {
/* lwp_unsleep() releases the LWP lock. */
lwp_unsleep(l);
} else
lwp_unlock(l);
} else {
/*
* Not yet asleep. Reset its state below so that
* it will go around again.
*/
}
l->l_selflag = SEL_RESET;
}
mutex_exit(&select_lock);
}
void
selnotify(struct selinfo *sip, long knhint)
{
selwakeup(sip);
KNOTE(&sip->sel_klist, knhint);
}
/*
* Remove an LWP from all objects that it is waiting for.
*/
static void
selclear(void)
{
struct selinfo *sip;
lwp_t *l = curlwp;
KASSERT(mutex_owned(&select_lock));
SLIST_FOREACH(sip, &l->l_selwait, sel_chain) {
KASSERT(sip->sel_lwp == l);
sip->sel_lwp = NULL;
}
}
/*
* Initialize the select/poll system calls.
*/
void
selsysinit(void)
{
mutex_init(&select_lock, MUTEX_DRIVER, IPL_VM);
cv_init(&select_cv, "select");
}
/*
* Initialize a selector.
*/
void
selinit(struct selinfo *sip)
{
memset(sip, 0, sizeof(*sip));
}
/*
* Destroy a selector. The owning object must not gain new
* references while this is in progress: all activity on the
* selector must be stopped.
*/
void
seldestroy(struct selinfo *sip)
{
lwp_t *l;
if (sip->sel_lwp == NULL)
return;
mutex_enter(&select_lock);
if ((l = sip->sel_lwp) != NULL) {
/* This should rarely happen, so SLIST_REMOVE() is OK. */
SLIST_REMOVE(&l->l_selwait, sip, selinfo, sel_chain);
sip->sel_lwp = NULL;
}
mutex_exit(&select_lock);
}
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