d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
eb725b4e6a
freebsd-dev/sys/kern/sys_generic.c
Matthew Dillon b064d43d8f remove holdfp() 
Replace uses of holdfp() with fget*() or fgetvp*() calls as appropriate

introduce fget(), fget_read(), fget_write() - these functions will take
a thread and file descriptor and return a file pointer with its ref
count bumped.

introduce fgetvp(), fgetvp_read(), fgetvp_write() - these functions will
take a thread and file descriptor and return a vref()'d vnode.

*_read() requires that the file pointer be FREAD, *_write that it be
FWRITE.

This continues the cleanup of struct filedesc and struct file access
routines which, when are all through with it, will allow us to then
make the API calls MP safe and be able to move Giant down into the fo_*
functions.
2001-11-14 06:30:36 +00:00

1299 lines
28 KiB
C
Raw Blame History

/*
* 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/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/resourcevar.h>
#include <sys/selinfo.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/condvar.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <vm/vm.h>
#include <vm/vm_page.h>
#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 thread *, struct pollfd *, u_int));
static int pollholddrop __P((struct thread *, struct pollfd *, u_int, int));
static int selscan __P((struct thread *, fd_mask **, fd_mask **, int));
static int selholddrop __P((struct thread *, fd_mask *, fd_mask *, int, int));
static int dofileread __P((struct thread *, struct file *, int, void *,
size_t, off_t, int));
static int dofilewrite __P((struct thread *, struct file *, int,
const void *, size_t, off_t, int));
/*
* Read system call.
*/
#ifndef _SYS_SYSPROTO_H_
struct read_args {
int fd;
void *buf;
size_t nbyte;
};
#endif
/*
* MPSAFE
*/
int
read(td, uap)
struct thread *td;
struct read_args *uap;
{
struct file *fp;
int error;
mtx_lock(&Giant);
if ((error = fget_read(td, uap->fd, &fp)) == 0) {
error = dofileread(td, fp, uap->fd, uap->buf,
uap->nbyte, (off_t)-1, 0);
fdrop(fp, td);
}
mtx_unlock(&Giant);
return(error);
}
/*
* Pread system call
*/
#ifndef _SYS_SYSPROTO_H_
struct pread_args {
int fd;
void *buf;
size_t nbyte;
int pad;
off_t offset;
};
#endif
/*
* MPSAFE
*/
int
pread(td, uap)
struct thread *td;
struct pread_args *uap;
{
struct file *fp;
int error;
mtx_lock(&Giant);
if ((error = fget_read(td, uap->fd, &fp)) == 0) {
if (fp->f_type == DTYPE_VNODE) {
error = dofileread(td, fp, uap->fd, uap->buf,
uap->nbyte, uap->offset, FOF_OFFSET);
} else {
error = ESPIPE;
}
fdrop(fp, td);
}
mtx_unlock(&Giant);
return(error);
}
/*
* Code common for read and pread
*/
int
dofileread(td, fp, fd, buf, nbyte, offset, flags)
struct thread *td;
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;
struct uio ktruio;
int didktr = 0;
#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_td = td;
#ifdef KTRACE
/*
* if tracing, save a copy of iovec
*/
if (KTRPOINT(td->td_proc, KTR_GENIO)) {
ktriov = aiov;
ktruio = auio;
didktr = 1;
}
#endif
cnt = nbyte;
if ((error = fo_read(fp, &auio, fp->f_cred, flags, td))) {
if (auio.uio_resid != cnt && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
}
cnt -= auio.uio_resid;
#ifdef KTRACE
if (didktr && error == 0) {
ktruio.uio_iov = &ktriov;
ktruio.uio_resid = cnt;
ktrgenio(td->td_proc->p_tracep, fd, UIO_READ, &ktruio, error);
}
#endif
td->td_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
/*
* MPSAFE
*/
int
readv(td, uap)
struct thread *td;
struct readv_args *uap;
{
struct file *fp;
struct uio auio;
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;
struct uio ktruio;
#endif
mtx_lock(&Giant);
if ((error = fget_read(td, uap->fd, &fp)) != 0)
goto done2;
/* 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) {
error = EINVAL;
goto done2;
}
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_td = td;
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(td->td_proc, KTR_GENIO)) {
MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen);
ktruio = auio;
}
#endif
cnt = auio.uio_resid;
if ((error = fo_read(fp, &auio, fp->f_cred, 0, td))) {
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) {
ktruio.uio_iov = ktriov;
ktruio.uio_resid = cnt;
ktrgenio(td->td_proc->p_tracep, uap->fd, UIO_READ, &ktruio,
error);
}
FREE(ktriov, M_TEMP);
}
#endif
td->td_retval[0] = cnt;
done:
fdrop(fp, td);
if (needfree)
FREE(needfree, M_IOV);
done2:
mtx_unlock(&Giant);
return (error);
}
/*
* Write system call
*/
#ifndef _SYS_SYSPROTO_H_
struct write_args {
int fd;
const void *buf;
size_t nbyte;
};
#endif
/*
* MPSAFE
*/
int
write(td, uap)
struct thread *td;
struct write_args *uap;
{
struct file *fp;
int error;
mtx_lock(&Giant);
if ((error = fget_write(td, uap->fd, &fp)) == 0) {
error = dofilewrite(td, fp, uap->fd, uap->buf, uap->nbyte,
(off_t)-1, 0);
fdrop(fp, td);
} else {
error = EBADF; /* XXX this can't be right */
}
mtx_unlock(&Giant);
return(error);
}
/*
* Pwrite system call
*/
#ifndef _SYS_SYSPROTO_H_
struct pwrite_args {
int fd;
const void *buf;
size_t nbyte;
int pad;
off_t offset;
};
#endif
/*
* MPSAFE
*/
int
pwrite(td, uap)
struct thread *td;
struct pwrite_args *uap;
{
struct file *fp;
int error;
mtx_lock(&Giant);
if ((error = fget_write(td, uap->fd, &fp)) == 0) {
if (fp->f_type == DTYPE_VNODE) {
error = dofilewrite(td, fp, uap->fd, uap->buf,
uap->nbyte, uap->offset, FOF_OFFSET);
} else {
error = ESPIPE;
}
fdrop(fp, td);
} else {
error = EBADF; /* this can't be right */
}
mtx_unlock(&Giant);
return(error);
}
static int
dofilewrite(td, fp, fd, buf, nbyte, offset, flags)
struct thread *td;
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;
struct uio ktruio;
int didktr = 0;
#endif
aiov.iov_base = (void *)(uintptr_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_WRITE;
auio.uio_segflg = UIO_USERSPACE;
auio.uio_td = td;
#ifdef KTRACE
/*
* if tracing, save a copy of iovec and uio
*/
if (KTRPOINT(td->td_proc, KTR_GENIO)) {
ktriov = aiov;
ktruio = auio;
didktr = 1;
}
#endif
cnt = nbyte;
if (fp->f_type == DTYPE_VNODE)
bwillwrite();
if ((error = fo_write(fp, &auio, fp->f_cred, flags, td))) {
if (auio.uio_resid != cnt && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
if (error == EPIPE) {
PROC_LOCK(td->td_proc);
psignal(td->td_proc, SIGPIPE);
PROC_UNLOCK(td->td_proc);
}
}
cnt -= auio.uio_resid;
#ifdef KTRACE
if (didktr && error == 0) {
ktruio.uio_iov = &ktriov;
ktruio.uio_resid = cnt;
ktrgenio(td->td_proc->p_tracep, fd, UIO_WRITE, &ktruio, error);
}
#endif
td->td_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
/*
* MPSAFE
*/
int
writev(td, uap)
struct thread *td;
register struct writev_args *uap;
{
struct file *fp;
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;
struct uio ktruio;
#endif
mtx_lock(&Giant);
if ((error = fget_write(td, uap->fd, &fp)) != 0) {
error = EBADF;
goto done2;
}
/* 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_td = td;
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 and uio
*/
if (KTRPOINT(td->td_proc, KTR_GENIO)) {
MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
bcopy((caddr_t)auio.uio_iov, (caddr_t)ktriov, iovlen);
ktruio = auio;
}
#endif
cnt = auio.uio_resid;
if (fp->f_type == DTYPE_VNODE)
bwillwrite();
if ((error = fo_write(fp, &auio, fp->f_cred, 0, td))) {
if (auio.uio_resid != cnt && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
if (error == EPIPE) {
PROC_LOCK(td->td_proc);
psignal(td->td_proc, SIGPIPE);
PROC_UNLOCK(td->td_proc);
}
}
cnt -= auio.uio_resid;
#ifdef KTRACE
if (ktriov != NULL) {
if (error == 0) {
ktruio.uio_iov = ktriov;
ktruio.uio_resid = cnt;
ktrgenio(td->td_proc->p_tracep, uap->fd, UIO_WRITE, &ktruio,
error);
}
FREE(ktriov, M_TEMP);
}
#endif
td->td_retval[0] = cnt;
done:
fdrop(fp, td);
if (needfree)
FREE(needfree, M_IOV);
done2:
mtx_unlock(&Giant);
return (error);
}
/*
* Ioctl system call
*/
#ifndef _SYS_SYSPROTO_H_
struct ioctl_args {
int fd;
u_long com;
caddr_t data;
};
#endif
/*
* MPSAFE
*/
/* ARGSUSED */
int
ioctl(td, uap)
struct thread *td;
register struct ioctl_args *uap;
{
register struct file *fp;
register struct filedesc *fdp;
register u_long com;
int error = 0;
register u_int size;
caddr_t data, memp;
int tmp;
#define STK_PARAMS 128
union {
char stkbuf[STK_PARAMS];
long align;
} ubuf;
mtx_lock(&Giant);
fdp = td->td_proc->p_fd;
if ((u_int)uap->fd >= fdp->fd_nfiles ||
(fp = fdp->fd_ofiles[uap->fd]) == NULL) {
error = EBADF;
goto done2;
}
if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
error = EBADF;
goto done2;
}
switch (com = uap->com) {
case FIONCLEX:
fdp->fd_ofileflags[uap->fd] &= ~UF_EXCLOSE;
goto done2;
case FIOCLEX:
fdp->fd_ofileflags[uap->fd] |= UF_EXCLOSE;
goto done2;
}
/*
* 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 done2;
}
fhold(fp);
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);
fdrop(fp, td);
goto done2;
}
} 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, td);
break;
case FIOASYNC:
if ((tmp = *(int *)data))
fp->f_flag |= FASYNC;
else
fp->f_flag &= ~FASYNC;
error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, td);
break;
default:
error = fo_ioctl(fp, com, data, td);
/*
* 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);
fdrop(fp, td);
done2:
mtx_unlock(&Giant);
return (error);
}
static int nselcoll; /* Select collisions since boot */
struct cv 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
/*
* MPSAFE
*/
int
select(td, uap)
register struct thread *td;
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 s_heldbits[howmany(2048, NFDBITS)];
fd_mask *ibits[3], *obits[3], *selbits, *sbp, *heldbits, *hibits, *hobits;
struct timeval atv, rtv, ttv;
int ncoll, error, timo, i;
u_int nbufbytes, ncpbytes, nfdbits;
if (uap->nd < 0)
return (EINVAL);
mtx_lock(&Giant);
if (uap->nd > td->td_proc->p_fd->fd_nfiles)
uap->nd = td->td_proc->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);
if (2 * ncpbytes <= sizeof s_heldbits) {
bzero(s_heldbits, sizeof(s_heldbits));
heldbits = &s_heldbits[0];
} else
heldbits = malloc(2 * ncpbytes, M_SELECT, M_WAITOK | M_ZERO);
/*
* 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;
hibits = heldbits + ncpbytes / sizeof *heldbits;
hobits = heldbits;
#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_noproclock; \
for (i = 0; \
i < ncpbytes / sizeof ibits[i][0]; \
i++) \
hibits[i] |= ibits[x][i]; \
} \
} 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_noproclock;
if (itimerfix(&atv)) {
error = EINVAL;
goto done_noproclock;
}
getmicrouptime(&rtv);
timevaladd(&atv, &rtv);
} else {
atv.tv_sec = 0;
atv.tv_usec = 0;
}
selholddrop(td, hibits, hobits, uap->nd, 1);
timo = 0;
PROC_LOCK(td->td_proc);
retry:
ncoll = nselcoll;
mtx_lock_spin(&sched_lock);
td->td_flags |= TDF_SELECT;
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(td->td_proc);
error = selscan(td, ibits, obits, uap->nd);
PROC_LOCK(td->td_proc);
if (error || td->td_retval[0])
goto done;
if (atv.tv_sec || atv.tv_usec) {
getmicrouptime(&rtv);
if (timevalcmp(&rtv, &atv, >=)) {
/*
* An event of our interest may occur during locking a process.
* In order to avoid missing the event that occured during locking
* the process, test TDF_SELECT and rescan file descriptors if
* necessary.
*/
mtx_lock_spin(&sched_lock);
if ((td->td_flags & TDF_SELECT) == 0 || nselcoll != ncoll) {
ncoll = nselcoll;
td->td_flags |= TDF_SELECT;
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(td->td_proc);
error = selscan(td, ibits, obits, uap->nd);
PROC_LOCK(td->td_proc);
} else
mtx_unlock_spin(&sched_lock);
goto done;
}
ttv = atv;
timevalsub(&ttv, &rtv);
timo = ttv.tv_sec > 24 * 60 * 60 ?
24 * 60 * 60 * hz : tvtohz(&ttv);
}
mtx_lock_spin(&sched_lock);
td->td_flags &= ~TDF_SELECT;
mtx_unlock_spin(&sched_lock);
if (timo > 0)
error = cv_timedwait_sig(&selwait, &td->td_proc->p_mtx, timo);
else
error = cv_wait_sig(&selwait, &td->td_proc->p_mtx);
if (error == 0)
goto retry;
done:
mtx_lock_spin(&sched_lock);
td->td_flags &= ~TDF_SELECT;
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(td->td_proc);
selholddrop(td, hibits, hobits, uap->nd, 0);
done_noproclock:
/* 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);
if (heldbits != &s_heldbits[0])
free(heldbits, M_SELECT);
mtx_unlock(&Giant);
return (error);
}
static int
selholddrop(td, ibits, obits, nfd, hold)
struct thread *td;
fd_mask *ibits, *obits;
int nfd, hold;
{
struct filedesc *fdp = td->td_proc->p_fd;
int i, fd;
fd_mask bits;
struct file *fp;
for (i = 0; i < nfd; i += NFDBITS) {
if (hold)
bits = ibits[i/NFDBITS];
else
bits = obits[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 (hold) {
fhold(fp);
obits[(fd)/NFDBITS] |=
((fd_mask)1 << ((fd) % NFDBITS));
} else
fdrop(fp, td);
}
}
return (0);
}
static int
selscan(td, ibits, obits, nfd)
struct thread *td;
fd_mask **ibits, **obits;
int nfd;
{
struct filedesc *fdp = td->td_proc->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, td)) {
obits[msk][(fd)/NFDBITS] |=
((fd_mask)1 << ((fd) % NFDBITS));
n++;
}
}
}
}
td->td_retval[0] = n;
return (0);
}
/*
* Poll system call.
*/
#ifndef _SYS_SYSPROTO_H_
struct poll_args {
struct pollfd *fds;
u_int nfds;
int timeout;
};
#endif
/*
* MPSAFE
*/
int
poll(td, uap)
struct thread *td;
struct poll_args *uap;
{
caddr_t bits;
char smallbits[32 * sizeof(struct pollfd)];
struct timeval atv, rtv, ttv;
int ncoll, error = 0, timo;
u_int nfds;
size_t ni;
struct pollfd p_heldbits[32];
struct pollfd *heldbits;
nfds = SCARG(uap, nfds);
mtx_lock(&Giant);
/*
* This is kinda bogus. We have fd limits, but that is not
* really related to the size of the pollfd array. Make sure
* we let the process use at least FD_SETSIZE entries and at
* least enough for the current limits. We want to be reasonably
* safe, but not overly restrictive.
*/
if ((nfds > td->td_proc->p_rlimit[RLIMIT_NOFILE].rlim_cur) &&
(nfds > FD_SETSIZE)) {
error = EINVAL;
goto done2;
}
ni = nfds * sizeof(struct pollfd);
if (ni > sizeof(smallbits))
bits = malloc(ni, M_TEMP, M_WAITOK);
else
bits = smallbits;
if (ni > sizeof(p_heldbits))
heldbits = malloc(ni, M_TEMP, M_WAITOK);
else {
bzero(p_heldbits, sizeof(p_heldbits));
heldbits = p_heldbits;
}
error = copyin(SCARG(uap, fds), bits, ni);
if (error)
goto done_noproclock;
bcopy(bits, heldbits, ni);
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_noproclock;
}
getmicrouptime(&rtv);
timevaladd(&atv, &rtv);
} else {
atv.tv_sec = 0;
atv.tv_usec = 0;
}
pollholddrop(td, heldbits, nfds, 1);
timo = 0;
PROC_LOCK(td->td_proc);
retry:
ncoll = nselcoll;
mtx_lock_spin(&sched_lock);
td->td_flags |= TDF_SELECT;
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(td->td_proc);
error = pollscan(td, (struct pollfd *)bits, nfds);
PROC_LOCK(td->td_proc);
if (error || td->td_retval[0])
goto done;
if (atv.tv_sec || atv.tv_usec) {
getmicrouptime(&rtv);
if (timevalcmp(&rtv, &atv, >=)) {
/*
* An event of our interest may occur during locking a process.
* In order to avoid missing the event that occured during locking
* the process, test TDF_SELECT and rescan file descriptors if
* necessary.
*/
mtx_lock_spin(&sched_lock);
if ((td->td_flags & TDF_SELECT) == 0 || nselcoll != ncoll) {
ncoll = nselcoll;
td->td_flags |= TDF_SELECT;
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(td->td_proc);
error = pollscan(td, (struct pollfd *)bits, nfds);
PROC_LOCK(td->td_proc);
} else
mtx_unlock_spin(&sched_lock);
goto done;
}
ttv = atv;
timevalsub(&ttv, &rtv);
timo = ttv.tv_sec > 24 * 60 * 60 ?
24 * 60 * 60 * hz : tvtohz(&ttv);
}
mtx_lock_spin(&sched_lock);
td->td_flags &= ~TDF_SELECT;
mtx_unlock_spin(&sched_lock);
if (timo > 0)
error = cv_timedwait_sig(&selwait, &td->td_proc->p_mtx, timo);
else
error = cv_wait_sig(&selwait, &td->td_proc->p_mtx);
if (error == 0)
goto retry;
done:
mtx_lock_spin(&sched_lock);
td->td_flags &= ~TDF_SELECT;
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(td->td_proc);
pollholddrop(td, heldbits, nfds, 0);
done_noproclock:
/* 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);
if (ni > sizeof(p_heldbits))
free(heldbits, M_TEMP);
done2:
mtx_unlock(&Giant);
return (error);
}
static int
pollholddrop(td, fds, nfd, hold)
struct thread *td;
struct pollfd *fds;
u_int nfd;
int hold;
{
register struct filedesc *fdp = td->td_proc->p_fd;
int i;
struct file *fp;
for (i = 0; i < nfd; i++, fds++) {
if (0 <= fds->fd && fds->fd < fdp->fd_nfiles) {
fp = fdp->fd_ofiles[fds->fd];
if (hold) {
if (fp != NULL) {
fhold(fp);
fds->revents = 1;
} else
fds->revents = 0;
} else if(fp != NULL && fds->revents)
fdrop(fp, td);
}
}
return (0);
}
static int
pollscan(td, fds, nfd)
struct thread *td;
struct pollfd *fds;
u_int nfd;
{
register struct filedesc *fdp = td->td_proc->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 == NULL) {
fds->revents = POLLNVAL;
n++;
} else {
/*
* Note: backend also returns POLLHUP and
* POLLERR if appropriate.
*/
fds->revents = fo_poll(fp, fds->events,
fp->f_cred, td);
if (fds->revents != 0)
n++;
}
}
}
td->td_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
/*
* MPSAFE
*/
int
openbsd_poll(td, uap)
register struct thread *td;
register struct openbsd_poll_args *uap;
{
return (poll(td, (struct poll_args *)uap));
}
/*ARGSUSED*/
int
seltrue(dev, events, td)
dev_t dev;
int events;
struct thread *td;
{
return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
}
static int
find_thread_in_proc(struct proc *p, struct thread *td)
{
struct thread *td2;
FOREACH_THREAD_IN_PROC(p, td2) {
if (td2 == td) {
return (1);
}
}
return (0);
}
/*
* Record a select request.
*/
void
selrecord(selector, sip)
struct thread *selector;
struct selinfo *sip;
{
struct proc *p;
pid_t mypid;
mypid = selector->td_proc->p_pid;
if ((sip->si_pid == mypid) &&
(sip->si_thread == selector)) { /* XXXKSE should be an ID? */
return;
}
if (sip->si_pid &&
(p = pfind(sip->si_pid)) &&
(find_thread_in_proc(p, sip->si_thread))) {
mtx_lock_spin(&sched_lock);
if (sip->si_thread->td_wchan == (caddr_t)&selwait) {
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p);
sip->si_flags |= SI_COLL;
return;
}
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p);
}
sip->si_pid = mypid;
sip->si_thread = selector;
}
/*
* Do a wakeup when a selectable event occurs.
*/
void
selwakeup(sip)
register struct selinfo *sip;
{
struct thread *td;
register struct proc *p;
if (sip->si_pid == 0)
return;
if (sip->si_flags & SI_COLL) {
nselcoll++;
sip->si_flags &= ~SI_COLL;
cv_broadcast(&selwait);
}
p = pfind(sip->si_pid);
sip->si_pid = 0;
td = sip->si_thread;
if (p != NULL) {
if (!find_thread_in_proc(p, td)) {
PROC_UNLOCK(p); /* lock is in pfind() */;
return;
}
mtx_lock_spin(&sched_lock);
if (td->td_wchan == (caddr_t)&selwait) {
if (td->td_proc->p_stat == SSLEEP)
setrunnable(td);
else
cv_waitq_remove(td);
} else
td->td_flags &= ~TDF_SELECT;
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p); /* Lock is in pfind() */
}
}
static void selectinit __P((void *));
SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, selectinit, NULL)
/* ARGSUSED*/
static void
selectinit(dummy)
void *dummy;
{
cv_init(&selwait, "select");
}
Reference in New Issue View Git Blame Copy Permalink