/
sys_generic.c
1274 lines (1124 loc) · 30.1 KB
/
sys_generic.c
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/* $OpenBSD: sys_generic.c,v 1.152 2023/02/10 14:34:17 visa 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. 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/filedesc.h>
#include <sys/ioctl.h>
#include <sys/fcntl.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/socketvar.h>
#include <sys/signalvar.h>
#include <sys/uio.h>
#include <sys/time.h>
#include <sys/malloc.h>
#include <sys/poll.h>
#include <sys/eventvar.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <sys/pledge.h>
#include <sys/mount.h>
#include <sys/syscallargs.h>
/*
* Debug values:
* 1 - print implementation errors, things that should not happen.
* 2 - print ppoll(2) information, somewhat verbose
* 3 - print pselect(2) and ppoll(2) information, very verbose
*/
int kqpoll_debug = 0;
#define DPRINTFN(v, x...) if (kqpoll_debug > v) { \
printf("%s(%d): ", curproc->p_p->ps_comm, curproc->p_tid); \
printf(x); \
}
int pselregister(struct proc *, fd_set **, fd_set **, int, int *, int *);
int pselcollect(struct proc *, struct kevent *, fd_set **, int *);
void ppollregister(struct proc *, struct pollfd *, int, int *, int *);
int ppollcollect(struct proc *, struct kevent *, struct pollfd *, u_int);
int pollout(struct pollfd *, struct pollfd *, u_int);
int dopselect(struct proc *, int, fd_set *, fd_set *, fd_set *,
struct timespec *, const sigset_t *, register_t *);
int doppoll(struct proc *, struct pollfd *, u_int, struct timespec *,
const sigset_t *, register_t *);
int
iovec_copyin(const struct iovec *uiov, struct iovec **iovp, struct iovec *aiov,
unsigned int iovcnt, size_t *residp)
{
#ifdef KTRACE
struct proc *p = curproc;
#endif
struct iovec *iov;
int error, i;
size_t resid = 0;
if (iovcnt > UIO_SMALLIOV) {
if (iovcnt > IOV_MAX)
return (EINVAL);
iov = mallocarray(iovcnt, sizeof(*iov), M_IOV, M_WAITOK);
} else if (iovcnt > 0) {
iov = aiov;
} else {
return (EINVAL);
}
*iovp = iov;
if ((error = copyin(uiov, iov, iovcnt * sizeof(*iov))))
return (error);
#ifdef KTRACE
if (KTRPOINT(p, KTR_STRUCT))
ktriovec(p, iov, iovcnt);
#endif
for (i = 0; i < iovcnt; i++) {
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. Note that the addition is
* guaranteed to not wrap because SSIZE_MAX * 2 < SIZE_MAX.
*/
if (iov->iov_len > SSIZE_MAX || resid > SSIZE_MAX)
return (EINVAL);
iov++;
}
if (residp != NULL)
*residp = resid;
return (0);
}
void
iovec_free(struct iovec *iov, unsigned int iovcnt)
{
if (iovcnt > UIO_SMALLIOV)
free(iov, M_IOV, iovcnt * sizeof(*iov));
}
/*
* Read system call.
*/
int
sys_read(struct proc *p, void *v, register_t *retval)
{
struct sys_read_args /* {
syscallarg(int) fd;
syscallarg(void *) buf;
syscallarg(size_t) nbyte;
} */ *uap = v;
struct iovec iov;
struct uio auio;
iov.iov_base = SCARG(uap, buf);
iov.iov_len = SCARG(uap, nbyte);
if (iov.iov_len > SSIZE_MAX)
return (EINVAL);
auio.uio_iov = &iov;
auio.uio_iovcnt = 1;
auio.uio_resid = iov.iov_len;
return (dofilereadv(p, SCARG(uap, fd), &auio, 0, retval));
}
/*
* Scatter read system call.
*/
int
sys_readv(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;
struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
int error, iovcnt = SCARG(uap, iovcnt);
struct uio auio;
size_t resid;
error = iovec_copyin(SCARG(uap, iovp), &iov, aiov, iovcnt, &resid);
if (error)
goto done;
auio.uio_iov = iov;
auio.uio_iovcnt = iovcnt;
auio.uio_resid = resid;
error = dofilereadv(p, SCARG(uap, fd), &auio, 0, retval);
done:
iovec_free(iov, iovcnt);
return (error);
}
int
dofilereadv(struct proc *p, int fd, struct uio *uio, int flags,
register_t *retval)
{
struct filedesc *fdp = p->p_fd;
struct file *fp;
long cnt, error = 0;
u_int iovlen;
#ifdef KTRACE
struct iovec *ktriov = NULL;
#endif
KASSERT(uio->uio_iov != NULL && uio->uio_iovcnt > 0);
iovlen = uio->uio_iovcnt * sizeof(struct iovec);
if ((fp = fd_getfile_mode(fdp, fd, FREAD)) == NULL)
return (EBADF);
/* Checks for positioned read. */
if (flags & FO_POSITION) {
struct vnode *vp = fp->f_data;
if (fp->f_type != DTYPE_VNODE || vp->v_type == VFIFO ||
(vp->v_flag & VISTTY)) {
error = ESPIPE;
goto done;
}
if (uio->uio_offset < 0 && vp->v_type != VCHR) {
error = EINVAL;
goto done;
}
}
uio->uio_rw = UIO_READ;
uio->uio_segflg = UIO_USERSPACE;
uio->uio_procp = p;
#ifdef KTRACE
/*
* if tracing, save a copy of iovec
*/
if (KTRPOINT(p, KTR_GENIO)) {
ktriov = malloc(iovlen, M_TEMP, M_WAITOK);
memcpy(ktriov, uio->uio_iov, iovlen);
}
#endif
cnt = uio->uio_resid;
error = (*fp->f_ops->fo_read)(fp, uio, flags);
if (error) {
if (uio->uio_resid != cnt && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
}
cnt -= uio->uio_resid;
mtx_enter(&fp->f_mtx);
fp->f_rxfer++;
fp->f_rbytes += cnt;
mtx_leave(&fp->f_mtx);
#ifdef KTRACE
if (ktriov != NULL) {
if (error == 0)
ktrgenio(p, fd, UIO_READ, ktriov, cnt);
free(ktriov, M_TEMP, iovlen);
}
#endif
*retval = cnt;
done:
FRELE(fp, p);
return (error);
}
/*
* Write system call
*/
int
sys_write(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;
struct iovec iov;
struct uio auio;
iov.iov_base = (void *)SCARG(uap, buf);
iov.iov_len = SCARG(uap, nbyte);
if (iov.iov_len > SSIZE_MAX)
return (EINVAL);
auio.uio_iov = &iov;
auio.uio_iovcnt = 1;
auio.uio_resid = iov.iov_len;
return (dofilewritev(p, SCARG(uap, fd), &auio, 0, retval));
}
/*
* Gather write system call
*/
int
sys_writev(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;
struct iovec aiov[UIO_SMALLIOV], *iov = NULL;
int error, iovcnt = SCARG(uap, iovcnt);
struct uio auio;
size_t resid;
error = iovec_copyin(SCARG(uap, iovp), &iov, aiov, iovcnt, &resid);
if (error)
goto done;
auio.uio_iov = iov;
auio.uio_iovcnt = iovcnt;
auio.uio_resid = resid;
error = dofilewritev(p, SCARG(uap, fd), &auio, 0, retval);
done:
iovec_free(iov, iovcnt);
return (error);
}
int
dofilewritev(struct proc *p, int fd, struct uio *uio, int flags,
register_t *retval)
{
struct filedesc *fdp = p->p_fd;
struct file *fp;
long cnt, error = 0;
u_int iovlen;
#ifdef KTRACE
struct iovec *ktriov = NULL;
#endif
KASSERT(uio->uio_iov != NULL && uio->uio_iovcnt > 0);
iovlen = uio->uio_iovcnt * sizeof(struct iovec);
if ((fp = fd_getfile_mode(fdp, fd, FWRITE)) == NULL)
return (EBADF);
/* Checks for positioned write. */
if (flags & FO_POSITION) {
struct vnode *vp = fp->f_data;
if (fp->f_type != DTYPE_VNODE || vp->v_type == VFIFO ||
(vp->v_flag & VISTTY)) {
error = ESPIPE;
goto done;
}
if (uio->uio_offset < 0 && vp->v_type != VCHR) {
error = EINVAL;
goto done;
}
}
uio->uio_rw = UIO_WRITE;
uio->uio_segflg = UIO_USERSPACE;
uio->uio_procp = p;
#ifdef KTRACE
/*
* if tracing, save a copy of iovec
*/
if (KTRPOINT(p, KTR_GENIO)) {
ktriov = malloc(iovlen, M_TEMP, M_WAITOK);
memcpy(ktriov, uio->uio_iov, iovlen);
}
#endif
cnt = uio->uio_resid;
error = (*fp->f_ops->fo_write)(fp, uio, flags);
if (error) {
if (uio->uio_resid != cnt && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
if (error == EPIPE) {
KERNEL_LOCK();
ptsignal(p, SIGPIPE, STHREAD);
KERNEL_UNLOCK();
}
}
cnt -= uio->uio_resid;
mtx_enter(&fp->f_mtx);
fp->f_wxfer++;
fp->f_wbytes += cnt;
mtx_leave(&fp->f_mtx);
#ifdef KTRACE
if (ktriov != NULL) {
if (error == 0)
ktrgenio(p, fd, UIO_WRITE, ktriov, cnt);
free(ktriov, M_TEMP, iovlen);
}
#endif
*retval = cnt;
done:
FRELE(fp, p);
return (error);
}
/*
* Ioctl system call
*/
int
sys_ioctl(struct proc *p, void *v, register_t *retval)
{
struct sys_ioctl_args /* {
syscallarg(int) fd;
syscallarg(u_long) com;
syscallarg(void *) data;
} */ *uap = v;
struct file *fp;
struct filedesc *fdp = p->p_fd;
u_long com = SCARG(uap, com);
int error = 0;
u_int size = 0;
caddr_t data, memp = NULL;
int tmp;
#define STK_PARAMS 128
long long stkbuf[STK_PARAMS / sizeof(long long)];
if ((fp = fd_getfile_mode(fdp, SCARG(uap, fd), FREAD|FWRITE)) == NULL)
return (EBADF);
if (fp->f_type == DTYPE_SOCKET) {
struct socket *so = fp->f_data;
if (so->so_state & SS_DNS) {
error = EINVAL;
goto out;
}
}
error = pledge_ioctl(p, com, fp);
if (error)
goto out;
switch (com) {
case FIONCLEX:
case FIOCLEX:
fdplock(fdp);
if (com == FIONCLEX)
fdp->fd_ofileflags[SCARG(uap, fd)] &= ~UF_EXCLOSE;
else
fdp->fd_ofileflags[SCARG(uap, fd)] |= UF_EXCLOSE;
fdpunlock(fdp);
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;
}
if (size > sizeof (stkbuf)) {
memp = malloc(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) {
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)
atomic_setbits_int(&fp->f_flag, FNONBLOCK);
else
atomic_clearbits_int(&fp->f_flag, FNONBLOCK);
error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, (caddr_t)&tmp, p);
break;
case FIOASYNC:
if ((tmp = *(int *)data) != 0)
atomic_setbits_int(&fp->f_flag, FASYNC);
else
atomic_clearbits_int(&fp->f_flag, FASYNC);
error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, (caddr_t)&tmp, p);
break;
default:
error = (*fp->f_ops->fo_ioctl)(fp, com, data, p);
break;
}
/*
* 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);
out:
FRELE(fp, p);
free(memp, M_IOCTLOPS, size);
return (error);
}
/*
* Select system call.
*/
int
sys_select(struct proc *p, 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 timespec ts, *tsp = NULL;
int error;
if (SCARG(uap, tv) != NULL) {
struct timeval tv;
if ((error = copyin(SCARG(uap, tv), &tv, sizeof tv)) != 0)
return (error);
#ifdef KTRACE
if (KTRPOINT(p, KTR_STRUCT))
ktrreltimeval(p, &tv);
#endif
if (tv.tv_sec < 0 || !timerisvalid(&tv))
return (EINVAL);
TIMEVAL_TO_TIMESPEC(&tv, &ts);
tsp = &ts;
}
return (dopselect(p, SCARG(uap, nd), SCARG(uap, in), SCARG(uap, ou),
SCARG(uap, ex), tsp, NULL, retval));
}
int
sys_pselect(struct proc *p, 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(const sigset_t *) mask;
} */ *uap = v;
struct timespec ts, *tsp = NULL;
sigset_t ss, *ssp = NULL;
int error;
if (SCARG(uap, ts) != NULL) {
if ((error = copyin(SCARG(uap, ts), &ts, sizeof ts)) != 0)
return (error);
#ifdef KTRACE
if (KTRPOINT(p, KTR_STRUCT))
ktrreltimespec(p, &ts);
#endif
if (ts.tv_sec < 0 || !timespecisvalid(&ts))
return (EINVAL);
tsp = &ts;
}
if (SCARG(uap, mask) != NULL) {
if ((error = copyin(SCARG(uap, mask), &ss, sizeof ss)) != 0)
return (error);
ssp = &ss;
}
return (dopselect(p, SCARG(uap, nd), SCARG(uap, in), SCARG(uap, ou),
SCARG(uap, ex), tsp, ssp, retval));
}
int
dopselect(struct proc *p, int nd, fd_set *in, fd_set *ou, fd_set *ex,
struct timespec *timeout, const sigset_t *sigmask, register_t *retval)
{
struct kqueue_scan_state scan;
struct timespec zerots = {};
fd_mask bits[6];
fd_set *pibits[3], *pobits[3];
int error, ncollected = 0, nevents = 0;
u_int ni;
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 > sizeof(bits[0])) {
caddr_t mbits;
mbits = mallocarray(6, ni, M_TEMP, M_WAITOK|M_ZERO);
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 {
memset(bits, 0, sizeof(bits));
pibits[0] = (fd_set *)&bits[0];
pibits[1] = (fd_set *)&bits[1];
pibits[2] = (fd_set *)&bits[2];
pobits[0] = (fd_set *)&bits[3];
pobits[1] = (fd_set *)&bits[4];
pobits[2] = (fd_set *)&bits[5];
}
kqpoll_init(nd);
#define getbits(name, x) \
if (name && (error = copyin(name, pibits[x], ni))) \
goto done;
getbits(in, 0);
getbits(ou, 1);
getbits(ex, 2);
#undef getbits
#ifdef KTRACE
if (ni > 0 && KTRPOINT(p, KTR_STRUCT)) {
if (in) ktrfdset(p, pibits[0], ni);
if (ou) ktrfdset(p, pibits[1], ni);
if (ex) ktrfdset(p, pibits[2], ni);
}
#endif
if (sigmask)
dosigsuspend(p, *sigmask &~ sigcantmask);
/* Register kqueue events */
error = pselregister(p, pibits, pobits, nd, &nevents, &ncollected);
if (error != 0)
goto done;
/*
* The poll/select family of syscalls has been designed to
* block when file descriptors are not available, even if
* there's nothing to wait for.
*/
if (nevents == 0 && ncollected == 0) {
uint64_t nsecs = INFSLP;
if (timeout != NULL) {
if (!timespecisset(timeout))
goto done;
nsecs = MAX(1, MIN(TIMESPEC_TO_NSEC(timeout), MAXTSLP));
}
error = tsleep_nsec(&nowake, PSOCK | PCATCH, "kqsel", nsecs);
/* select is not restarted after signals... */
if (error == ERESTART)
error = EINTR;
if (error == EWOULDBLOCK)
error = 0;
goto done;
}
/* Do not block if registering found pending events. */
if (ncollected > 0)
timeout = &zerots;
/* Collect at most `nevents' possibly waiting in kqueue_scan() */
kqueue_scan_setup(&scan, p->p_kq);
while (nevents > 0) {
struct kevent kev[KQ_NEVENTS];
int i, ready, count;
/* Maximum number of events per iteration */
count = MIN(nitems(kev), nevents);
ready = kqueue_scan(&scan, count, kev, timeout, p, &error);
/* Convert back events that are ready. */
for (i = 0; i < ready && error == 0; i++)
error = pselcollect(p, &kev[i], pobits, &ncollected);
/*
* Stop if there was an error or if we had enough
* space to collect all events that were ready.
*/
if (error || ready < count)
break;
nevents -= ready;
}
kqueue_scan_finish(&scan);
*retval = ncollected;
done:
#define putbits(name, x) \
if (name && (error2 = copyout(pobits[x], name, ni))) \
error = error2;
if (error == 0) {
int error2;
putbits(in, 0);
putbits(ou, 1);
putbits(ex, 2);
#undef putbits
#ifdef KTRACE
if (ni > 0 && KTRPOINT(p, KTR_STRUCT)) {
if (in) ktrfdset(p, pobits[0], ni);
if (ou) ktrfdset(p, pobits[1], ni);
if (ex) ktrfdset(p, pobits[2], ni);
}
#endif
}
if (pibits[0] != (fd_set *)&bits[0])
free(pibits[0], M_TEMP, 6 * ni);
kqpoll_done(nd);
return (error);
}
/*
* Convert fd_set into kqueue events and register them on the
* per-thread queue.
*/
int
pselregister(struct proc *p, fd_set *pibits[3], fd_set *pobits[3], int nfd,
int *nregistered, int *ncollected)
{
static const int evf[] = { EVFILT_READ, EVFILT_WRITE, EVFILT_EXCEPT };
static const int evff[] = { 0, 0, NOTE_OOB };
int msk, i, j, fd, nevents = 0, error = 0;
struct kevent kev;
fd_mask bits;
for (msk = 0; msk < 3; msk++) {
for (i = 0; i < nfd; i += NFDBITS) {
bits = pibits[msk]->fds_bits[i / NFDBITS];
while ((j = ffs(bits)) && (fd = i + --j) < nfd) {
bits &= ~(1 << j);
DPRINTFN(2, "select fd %d mask %d serial %lu\n",
fd, msk, p->p_kq_serial);
EV_SET(&kev, fd, evf[msk],
EV_ADD|EV_ENABLE|__EV_SELECT,
evff[msk], 0, (void *)(p->p_kq_serial));
error = kqueue_register(p->p_kq, &kev, 0, p);
switch (error) {
case 0:
nevents++;
/* FALLTHROUGH */
case EOPNOTSUPP:/* No underlying kqfilter */
case EINVAL: /* Unimplemented filter */
case EPERM: /* Specific to FIFO and
* __EV_SELECT */
error = 0;
break;
case EPIPE: /* Specific to pipes */
KASSERT(kev.filter == EVFILT_WRITE);
FD_SET(kev.ident, pobits[1]);
(*ncollected)++;
error = 0;
break;
case ENXIO: /* Device has been detached */
default:
goto bad;
}
}
}
}
*nregistered = nevents;
return (0);
bad:
DPRINTFN(0, "select fd %u filt %d error %d\n", (int)kev.ident,
kev.filter, error);
return (error);
}
/*
* Convert given kqueue event into corresponding select(2) bit.
*/
int
pselcollect(struct proc *p, struct kevent *kevp, fd_set *pobits[3],
int *ncollected)
{
if ((unsigned long)kevp->udata != p->p_kq_serial) {
panic("%s: spurious kevp %p fd %d udata 0x%lx serial 0x%lx",
__func__, kevp, (int)kevp->ident,
(unsigned long)kevp->udata, p->p_kq_serial);
}
if (kevp->flags & EV_ERROR) {
DPRINTFN(2, "select fd %d filt %d error %d\n",
(int)kevp->ident, kevp->filter, (int)kevp->data);
return (kevp->data);
}
switch (kevp->filter) {
case EVFILT_READ:
FD_SET(kevp->ident, pobits[0]);
break;
case EVFILT_WRITE:
FD_SET(kevp->ident, pobits[1]);
break;
case EVFILT_EXCEPT:
FD_SET(kevp->ident, pobits[2]);
break;
default:
KASSERT(0);
}
(*ncollected)++;
DPRINTFN(2, "select fd %d filt %d\n", (int)kevp->ident, kevp->filter);
return (0);
}
/*
* Do a wakeup when a selectable event occurs.
*/
void
selwakeup(struct selinfo *sip)
{
KERNEL_LOCK();
knote_locked(&sip->si_note, NOTE_SUBMIT);
KERNEL_UNLOCK();
}
/*
* Only copyout the revents field.
*/
int
pollout(struct pollfd *pl, struct pollfd *upl, u_int nfds)
{
int error = 0;
u_int i = 0;
while (!error && i++ < nfds) {
error = copyout(&pl->revents, &upl->revents,
sizeof(upl->revents));
pl++;
upl++;
}
return (error);
}
/*
* We are using the same mechanism as select only we encode/decode args
* differently.
*/
int
sys_poll(struct proc *p, void *v, register_t *retval)
{
struct sys_poll_args /* {
syscallarg(struct pollfd *) fds;
syscallarg(u_int) nfds;
syscallarg(int) timeout;
} */ *uap = v;
struct timespec ts, *tsp = NULL;
int msec = SCARG(uap, timeout);
if (msec != INFTIM) {
if (msec < 0)
return (EINVAL);
ts.tv_sec = msec / 1000;
ts.tv_nsec = (msec - (ts.tv_sec * 1000)) * 1000000;
tsp = &ts;
}
return (doppoll(p, SCARG(uap, fds), SCARG(uap, nfds), tsp, NULL,
retval));
}
int
sys_ppoll(struct proc *p, void *v, register_t *retval)
{
struct sys_ppoll_args /* {
syscallarg(struct pollfd *) fds;
syscallarg(u_int) nfds;
syscallarg(const struct timespec *) ts;
syscallarg(const sigset_t *) mask;
} */ *uap = v;
int error;
struct timespec ts, *tsp = NULL;
sigset_t ss, *ssp = NULL;
if (SCARG(uap, ts) != NULL) {
if ((error = copyin(SCARG(uap, ts), &ts, sizeof ts)) != 0)
return (error);
#ifdef KTRACE
if (KTRPOINT(p, KTR_STRUCT))
ktrreltimespec(p, &ts);
#endif
if (ts.tv_sec < 0 || !timespecisvalid(&ts))
return (EINVAL);
tsp = &ts;
}
if (SCARG(uap, mask) != NULL) {
if ((error = copyin(SCARG(uap, mask), &ss, sizeof ss)) != 0)
return (error);
ssp = &ss;
}
return (doppoll(p, SCARG(uap, fds), SCARG(uap, nfds), tsp, ssp,
retval));
}
int
doppoll(struct proc *p, struct pollfd *fds, u_int nfds,
struct timespec *timeout, const sigset_t *sigmask, register_t *retval)
{
struct kqueue_scan_state scan;
struct timespec zerots = {};
struct pollfd pfds[4], *pl = pfds;
int error, ncollected = 0, nevents = 0;
size_t sz;
/* Standards say no more than MAX_OPEN; this is possibly better. */
if (nfds > min((int)lim_cur(RLIMIT_NOFILE), maxfiles))
return (EINVAL);
/* optimize for the default case, of a small nfds value */
if (nfds > nitems(pfds)) {
pl = mallocarray(nfds, sizeof(*pl), M_TEMP,
M_WAITOK | M_CANFAIL);
if (pl == NULL)
return (EINVAL);
}
kqpoll_init(nfds);
sz = nfds * sizeof(*pl);
if ((error = copyin(fds, pl, sz)) != 0)
goto bad;
if (sigmask)
dosigsuspend(p, *sigmask &~ sigcantmask);
/* Register kqueue events */
ppollregister(p, pl, nfds, &nevents, &ncollected);
/*
* The poll/select family of syscalls has been designed to
* block when file descriptors are not available, even if
* there's nothing to wait for.
*/
if (nevents == 0 && ncollected == 0) {
uint64_t nsecs = INFSLP;
if (timeout != NULL) {
if (!timespecisset(timeout))
goto done;
nsecs = MAX(1, MIN(TIMESPEC_TO_NSEC(timeout), MAXTSLP));
}
error = tsleep_nsec(&nowake, PSOCK | PCATCH, "kqpoll", nsecs);
if (error == ERESTART)
error = EINTR;
if (error == EWOULDBLOCK)
error = 0;
goto done;
}
/* Do not block if registering found pending events. */
if (ncollected > 0)
timeout = &zerots;
/* Collect at most `nevents' possibly waiting in kqueue_scan() */
kqueue_scan_setup(&scan, p->p_kq);
while (nevents > 0) {
struct kevent kev[KQ_NEVENTS];
int i, ready, count;
/* Maximum number of events per iteration */
count = MIN(nitems(kev), nevents);
ready = kqueue_scan(&scan, count, kev, timeout, p, &error);
/* Convert back events that are ready. */
for (i = 0; i < ready; i++)
ncollected += ppollcollect(p, &kev[i], pl, nfds);
/*
* Stop if there was an error or if we had enough
* place to collect all events that were ready.
*/