/
sys_generic.c
1899 lines (1749 loc) · 41.4 KB
/
sys_generic.c
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/*-
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 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
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_capsicum.h"
#include "opt_compat.h"
#include "opt_ktrace.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/capsicum.h>
#include <sys/filedesc.h>
#include <sys/filio.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/lock.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/socketvar.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/limits.h>
#include <sys/malloc.h>
#include <sys/poll.h>
#include <sys/resourcevar.h>
#include <sys/selinfo.h>
#include <sys/sleepqueue.h>
#include <sys/syscallsubr.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/condvar.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <security/audit/audit.h>
/*
* The following macro defines how many bytes will be allocated from
* the stack instead of memory allocated when passing the IOCTL data
* structures from userspace and to the kernel. Some IOCTLs having
* small data structures are used very frequently and this small
* buffer on the stack gives a significant speedup improvement for
* those requests. The value of this define should be greater or equal
* to 64 bytes and should also be power of two. The data structure is
* currently hard-aligned to a 8-byte boundary on the stack. This
* should currently be sufficient for all supported platforms.
*/
#define SYS_IOCTL_SMALL_SIZE 128 /* bytes */
#define SYS_IOCTL_SMALL_ALIGN 8 /* bytes */
int iosize_max_clamp = 1;
SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW,
&iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX");
int devfs_iosize_max_clamp = 1;
SYSCTL_INT(_debug, OID_AUTO, devfs_iosize_max_clamp, CTLFLAG_RW,
&devfs_iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX for devices");
/*
* Assert that the return value of read(2) and write(2) syscalls fits
* into a register. If not, an architecture will need to provide the
* usermode wrappers to reconstruct the result.
*/
CTASSERT(sizeof(register_t) >= sizeof(size_t));
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 pollout(struct thread *, struct pollfd *, struct pollfd *,
u_int);
static int pollscan(struct thread *, struct pollfd *, u_int);
static int pollrescan(struct thread *);
static int selscan(struct thread *, fd_mask **, fd_mask **, int);
static int selrescan(struct thread *, fd_mask **, fd_mask **);
static void selfdalloc(struct thread *, void *);
static void selfdfree(struct seltd *, struct selfd *);
static int dofileread(struct thread *, int, struct file *, struct uio *,
off_t, int);
static int dofilewrite(struct thread *, int, struct file *, struct uio *,
off_t, int);
static void doselwakeup(struct selinfo *, int);
static void seltdinit(struct thread *);
static int seltdwait(struct thread *, sbintime_t, sbintime_t);
static void seltdclear(struct thread *);
/*
* One seltd per-thread allocated on demand as needed.
*
* t - protected by st_mtx
* k - Only accessed by curthread or read-only
*/
struct seltd {
STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */
struct selfd *st_free1; /* (k) free fd for read set. */
struct selfd *st_free2; /* (k) free fd for write set. */
struct mtx st_mtx; /* Protects struct seltd */
struct cv st_wait; /* (t) Wait channel. */
int st_flags; /* (t) SELTD_ flags. */
};
#define SELTD_PENDING 0x0001 /* We have pending events. */
#define SELTD_RESCAN 0x0002 /* Doing a rescan. */
/*
* One selfd allocated per-thread per-file-descriptor.
* f - protected by sf_mtx
*/
struct selfd {
STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */
TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */
struct selinfo *sf_si; /* (f) selinfo when linked. */
struct mtx *sf_mtx; /* Pointer to selinfo mtx. */
struct seltd *sf_td; /* (k) owning seltd. */
void *sf_cookie; /* (k) fd or pollfd. */
};
static uma_zone_t selfd_zone;
static struct mtx_pool *mtxpool_select;
#ifndef _SYS_SYSPROTO_H_
struct read_args {
int fd;
void *buf;
size_t nbyte;
};
#endif
int
sys_read(td, uap)
struct thread *td;
struct read_args *uap;
{
struct uio auio;
struct iovec aiov;
int error;
if (uap->nbyte > IOSIZE_MAX)
return (EINVAL);
aiov.iov_base = uap->buf;
aiov.iov_len = uap->nbyte;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_resid = uap->nbyte;
auio.uio_segflg = UIO_USERSPACE;
error = kern_readv(td, uap->fd, &auio);
return(error);
}
/*
* Positioned read system call
*/
#ifndef _SYS_SYSPROTO_H_
struct pread_args {
int fd;
void *buf;
size_t nbyte;
int pad;
off_t offset;
};
#endif
int
sys_pread(td, uap)
struct thread *td;
struct pread_args *uap;
{
struct uio auio;
struct iovec aiov;
int error;
if (uap->nbyte > IOSIZE_MAX)
return (EINVAL);
aiov.iov_base = uap->buf;
aiov.iov_len = uap->nbyte;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_resid = uap->nbyte;
auio.uio_segflg = UIO_USERSPACE;
error = kern_preadv(td, uap->fd, &auio, uap->offset);
return(error);
}
int
freebsd6_pread(td, uap)
struct thread *td;
struct freebsd6_pread_args *uap;
{
struct pread_args oargs;
oargs.fd = uap->fd;
oargs.buf = uap->buf;
oargs.nbyte = uap->nbyte;
oargs.offset = uap->offset;
return (sys_pread(td, &oargs));
}
/*
* Scatter read system call.
*/
#ifndef _SYS_SYSPROTO_H_
struct readv_args {
int fd;
struct iovec *iovp;
u_int iovcnt;
};
#endif
int
sys_readv(struct thread *td, struct readv_args *uap)
{
struct uio *auio;
int error;
error = copyinuio(uap->iovp, uap->iovcnt, &auio);
if (error)
return (error);
error = kern_readv(td, uap->fd, auio);
free(auio, M_IOV);
return (error);
}
int
kern_readv(struct thread *td, int fd, struct uio *auio)
{
struct file *fp;
cap_rights_t rights;
int error;
error = fget_read(td, fd, cap_rights_init(&rights, CAP_READ), &fp);
if (error)
return (error);
error = dofileread(td, fd, fp, auio, (off_t)-1, 0);
fdrop(fp, td);
return (error);
}
/*
* Scatter positioned read system call.
*/
#ifndef _SYS_SYSPROTO_H_
struct preadv_args {
int fd;
struct iovec *iovp;
u_int iovcnt;
off_t offset;
};
#endif
int
sys_preadv(struct thread *td, struct preadv_args *uap)
{
struct uio *auio;
int error;
error = copyinuio(uap->iovp, uap->iovcnt, &auio);
if (error)
return (error);
error = kern_preadv(td, uap->fd, auio, uap->offset);
free(auio, M_IOV);
return (error);
}
int
kern_preadv(td, fd, auio, offset)
struct thread *td;
int fd;
struct uio *auio;
off_t offset;
{
struct file *fp;
cap_rights_t rights;
int error;
error = fget_read(td, fd, cap_rights_init(&rights, CAP_PREAD), &fp);
if (error)
return (error);
if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
error = ESPIPE;
else if (offset < 0 && fp->f_vnode->v_type != VCHR)
error = EINVAL;
else
error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET);
fdrop(fp, td);
return (error);
}
/*
* Common code for readv and preadv that reads data in
* from a file using the passed in uio, offset, and flags.
*/
static int
dofileread(td, fd, fp, auio, offset, flags)
struct thread *td;
int fd;
struct file *fp;
struct uio *auio;
off_t offset;
int flags;
{
ssize_t cnt;
int error;
#ifdef KTRACE
struct uio *ktruio = NULL;
#endif
/* Finish zero length reads right here */
if (auio->uio_resid == 0) {
td->td_retval[0] = 0;
return(0);
}
auio->uio_rw = UIO_READ;
auio->uio_offset = offset;
auio->uio_td = td;
#ifdef KTRACE
if (KTRPOINT(td, KTR_GENIO))
ktruio = cloneuio(auio);
#endif
cnt = auio->uio_resid;
if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) {
if (auio->uio_resid != cnt && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
}
cnt -= auio->uio_resid;
#ifdef KTRACE
if (ktruio != NULL) {
ktruio->uio_resid = cnt;
ktrgenio(fd, UIO_READ, ktruio, error);
}
#endif
td->td_retval[0] = cnt;
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct write_args {
int fd;
const void *buf;
size_t nbyte;
};
#endif
int
sys_write(td, uap)
struct thread *td;
struct write_args *uap;
{
struct uio auio;
struct iovec aiov;
int error;
if (uap->nbyte > IOSIZE_MAX)
return (EINVAL);
aiov.iov_base = (void *)(uintptr_t)uap->buf;
aiov.iov_len = uap->nbyte;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_resid = uap->nbyte;
auio.uio_segflg = UIO_USERSPACE;
error = kern_writev(td, uap->fd, &auio);
return(error);
}
/*
* Positioned write system call.
*/
#ifndef _SYS_SYSPROTO_H_
struct pwrite_args {
int fd;
const void *buf;
size_t nbyte;
int pad;
off_t offset;
};
#endif
int
sys_pwrite(td, uap)
struct thread *td;
struct pwrite_args *uap;
{
struct uio auio;
struct iovec aiov;
int error;
if (uap->nbyte > IOSIZE_MAX)
return (EINVAL);
aiov.iov_base = (void *)(uintptr_t)uap->buf;
aiov.iov_len = uap->nbyte;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_resid = uap->nbyte;
auio.uio_segflg = UIO_USERSPACE;
error = kern_pwritev(td, uap->fd, &auio, uap->offset);
return(error);
}
int
freebsd6_pwrite(td, uap)
struct thread *td;
struct freebsd6_pwrite_args *uap;
{
struct pwrite_args oargs;
oargs.fd = uap->fd;
oargs.buf = uap->buf;
oargs.nbyte = uap->nbyte;
oargs.offset = uap->offset;
return (sys_pwrite(td, &oargs));
}
/*
* Gather write system call.
*/
#ifndef _SYS_SYSPROTO_H_
struct writev_args {
int fd;
struct iovec *iovp;
u_int iovcnt;
};
#endif
int
sys_writev(struct thread *td, struct writev_args *uap)
{
struct uio *auio;
int error;
error = copyinuio(uap->iovp, uap->iovcnt, &auio);
if (error)
return (error);
error = kern_writev(td, uap->fd, auio);
free(auio, M_IOV);
return (error);
}
int
kern_writev(struct thread *td, int fd, struct uio *auio)
{
struct file *fp;
cap_rights_t rights;
int error;
error = fget_write(td, fd, cap_rights_init(&rights, CAP_WRITE), &fp);
if (error)
return (error);
error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0);
fdrop(fp, td);
return (error);
}
/*
* Gather positioned write system call.
*/
#ifndef _SYS_SYSPROTO_H_
struct pwritev_args {
int fd;
struct iovec *iovp;
u_int iovcnt;
off_t offset;
};
#endif
int
sys_pwritev(struct thread *td, struct pwritev_args *uap)
{
struct uio *auio;
int error;
error = copyinuio(uap->iovp, uap->iovcnt, &auio);
if (error)
return (error);
error = kern_pwritev(td, uap->fd, auio, uap->offset);
free(auio, M_IOV);
return (error);
}
int
kern_pwritev(td, fd, auio, offset)
struct thread *td;
struct uio *auio;
int fd;
off_t offset;
{
struct file *fp;
cap_rights_t rights;
int error;
error = fget_write(td, fd, cap_rights_init(&rights, CAP_PWRITE), &fp);
if (error)
return (error);
if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
error = ESPIPE;
else if (offset < 0 && fp->f_vnode->v_type != VCHR)
error = EINVAL;
else
error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET);
fdrop(fp, td);
return (error);
}
/*
* Common code for writev and pwritev that writes data to
* a file using the passed in uio, offset, and flags.
*/
static int
dofilewrite(td, fd, fp, auio, offset, flags)
struct thread *td;
int fd;
struct file *fp;
struct uio *auio;
off_t offset;
int flags;
{
ssize_t cnt;
int error;
#ifdef KTRACE
struct uio *ktruio = NULL;
#endif
auio->uio_rw = UIO_WRITE;
auio->uio_td = td;
auio->uio_offset = offset;
#ifdef KTRACE
if (KTRPOINT(td, KTR_GENIO))
ktruio = cloneuio(auio);
#endif
cnt = auio->uio_resid;
if (fp->f_type == DTYPE_VNODE &&
(fp->f_vnread_flags & FDEVFS_VNODE) == 0)
bwillwrite();
if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) {
if (auio->uio_resid != cnt && (error == ERESTART ||
error == EINTR || error == EWOULDBLOCK))
error = 0;
/* Socket layer is responsible for issuing SIGPIPE. */
if (fp->f_type != DTYPE_SOCKET && error == EPIPE) {
PROC_LOCK(td->td_proc);
tdsignal(td, SIGPIPE);
PROC_UNLOCK(td->td_proc);
}
}
cnt -= auio->uio_resid;
#ifdef KTRACE
if (ktruio != NULL) {
ktruio->uio_resid = cnt;
ktrgenio(fd, UIO_WRITE, ktruio, error);
}
#endif
td->td_retval[0] = cnt;
return (error);
}
/*
* Truncate a file given a file descriptor.
*
* Can't use fget_write() here, since must return EINVAL and not EBADF if the
* descriptor isn't writable.
*/
int
kern_ftruncate(td, fd, length)
struct thread *td;
int fd;
off_t length;
{
struct file *fp;
cap_rights_t rights;
int error;
AUDIT_ARG_FD(fd);
if (length < 0)
return (EINVAL);
error = fget(td, fd, cap_rights_init(&rights, CAP_FTRUNCATE), &fp);
if (error)
return (error);
AUDIT_ARG_FILE(td->td_proc, fp);
if (!(fp->f_flag & FWRITE)) {
fdrop(fp, td);
return (EINVAL);
}
error = fo_truncate(fp, length, td->td_ucred, td);
fdrop(fp, td);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct ftruncate_args {
int fd;
int pad;
off_t length;
};
#endif
int
sys_ftruncate(td, uap)
struct thread *td;
struct ftruncate_args *uap;
{
return (kern_ftruncate(td, uap->fd, uap->length));
}
#if defined(COMPAT_43)
#ifndef _SYS_SYSPROTO_H_
struct oftruncate_args {
int fd;
long length;
};
#endif
int
oftruncate(td, uap)
struct thread *td;
struct oftruncate_args *uap;
{
return (kern_ftruncate(td, uap->fd, uap->length));
}
#endif /* COMPAT_43 */
#ifndef _SYS_SYSPROTO_H_
struct ioctl_args {
int fd;
u_long com;
caddr_t data;
};
#endif
/* ARGSUSED */
int
sys_ioctl(struct thread *td, struct ioctl_args *uap)
{
u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN);
u_long com;
int arg, error;
u_int size;
caddr_t data;
if (uap->com > 0xffffffff) {
printf(
"WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n",
td->td_proc->p_pid, td->td_name, uap->com);
uap->com &= 0xffffffff;
}
com = uap->com;
/*
* 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) ||
((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) ||
#if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
((com & IOC_OUT) && size == 0) ||
#else
((com & (IOC_IN | IOC_OUT)) && size == 0) ||
#endif
((com & IOC_VOID) && size > 0 && size != sizeof(int)))
return (ENOTTY);
if (size > 0) {
if (com & IOC_VOID) {
/* Integer argument. */
arg = (intptr_t)uap->data;
data = (void *)&arg;
size = 0;
} else {
if (size > SYS_IOCTL_SMALL_SIZE)
data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
else
data = smalldata;
}
} else
data = (void *)&uap->data;
if (com & IOC_IN) {
error = copyin(uap->data, data, (u_int)size);
if (error != 0)
goto out;
} else if (com & IOC_OUT) {
/*
* Zero the buffer so the user always
* gets back something deterministic.
*/
bzero(data, size);
}
error = kern_ioctl(td, uap->fd, com, data);
if (error == 0 && (com & IOC_OUT))
error = copyout(data, uap->data, (u_int)size);
out:
if (size > SYS_IOCTL_SMALL_SIZE)
free(data, M_IOCTLOPS);
return (error);
}
int
kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data)
{
struct file *fp;
struct filedesc *fdp;
#ifndef CAPABILITIES
cap_rights_t rights;
#endif
int error, tmp, locked;
AUDIT_ARG_FD(fd);
AUDIT_ARG_CMD(com);
fdp = td->td_proc->p_fd;
switch (com) {
case FIONCLEX:
case FIOCLEX:
FILEDESC_XLOCK(fdp);
locked = LA_XLOCKED;
break;
default:
#ifdef CAPABILITIES
FILEDESC_SLOCK(fdp);
locked = LA_SLOCKED;
#else
locked = LA_UNLOCKED;
#endif
break;
}
#ifdef CAPABILITIES
if ((fp = fget_locked(fdp, fd)) == NULL) {
error = EBADF;
goto out;
}
if ((error = cap_ioctl_check(fdp, fd, com)) != 0) {
fp = NULL; /* fhold() was not called yet */
goto out;
}
fhold(fp);
if (locked == LA_SLOCKED) {
FILEDESC_SUNLOCK(fdp);
locked = LA_UNLOCKED;
}
#else
error = fget(td, fd, cap_rights_init(&rights, CAP_IOCTL), &fp);
if (error != 0) {
fp = NULL;
goto out;
}
#endif
if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
error = EBADF;
goto out;
}
switch (com) {
case FIONCLEX:
fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE;
goto out;
case FIOCLEX:
fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE;
goto out;
case FIONBIO:
if ((tmp = *(int *)data))
atomic_set_int(&fp->f_flag, FNONBLOCK);
else
atomic_clear_int(&fp->f_flag, FNONBLOCK);
data = (void *)&tmp;
break;
case FIOASYNC:
if ((tmp = *(int *)data))
atomic_set_int(&fp->f_flag, FASYNC);
else
atomic_clear_int(&fp->f_flag, FASYNC);
data = (void *)&tmp;
break;
}
error = fo_ioctl(fp, com, data, td->td_ucred, td);
out:
switch (locked) {
case LA_XLOCKED:
FILEDESC_XUNLOCK(fdp);
break;
#ifdef CAPABILITIES
case LA_SLOCKED:
FILEDESC_SUNLOCK(fdp);
break;
#endif
default:
FILEDESC_UNLOCK_ASSERT(fdp);
break;
}
if (fp != NULL)
fdrop(fp, td);
return (error);
}
int
poll_no_poll(int events)
{
/*
* Return true for read/write. If the user asked for something
* special, return POLLNVAL, so that clients have a way of
* determining reliably whether or not the extended
* functionality is present without hard-coding knowledge
* of specific filesystem implementations.
*/
if (events & ~POLLSTANDARD)
return (POLLNVAL);
return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
}
int
sys_pselect(struct thread *td, struct pselect_args *uap)
{
struct timespec ts;
struct timeval tv, *tvp;
sigset_t set, *uset;
int error;
if (uap->ts != NULL) {
error = copyin(uap->ts, &ts, sizeof(ts));
if (error != 0)
return (error);
TIMESPEC_TO_TIMEVAL(&tv, &ts);
tvp = &tv;
} else
tvp = NULL;
if (uap->sm != NULL) {
error = copyin(uap->sm, &set, sizeof(set));
if (error != 0)
return (error);
uset = &set;
} else
uset = NULL;
return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
uset, NFDBITS));
}
int
kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex,
struct timeval *tvp, sigset_t *uset, int abi_nfdbits)
{
int error;
if (uset != NULL) {
error = kern_sigprocmask(td, SIG_SETMASK, uset,
&td->td_oldsigmask, 0);
if (error != 0)
return (error);
td->td_pflags |= TDP_OLDMASK;
/*
* Make sure that ast() is called on return to
* usermode and TDP_OLDMASK is cleared, restoring old
* sigmask.
*/
thread_lock(td);
td->td_flags |= TDF_ASTPENDING;
thread_unlock(td);
}
error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits);
return (error);
}
#ifndef _SYS_SYSPROTO_H_
struct select_args {
int nd;
fd_set *in, *ou, *ex;
struct timeval *tv;
};
#endif
int
sys_select(struct thread *td, struct select_args *uap)
{
struct timeval tv, *tvp;
int error;
if (uap->tv != NULL) {
error = copyin(uap->tv, &tv, sizeof(tv));
if (error)
return (error);
tvp = &tv;
} else
tvp = NULL;
return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
NFDBITS));
}
/*
* In the unlikely case when user specified n greater then the last
* open file descriptor, check that no bits are set after the last
* valid fd. We must return EBADF if any is set.
*
* There are applications that rely on the behaviour.
*
* nd is fd_lastfile + 1.
*/
static int
select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits)
{
char *addr, *oaddr;
int b, i, res;
uint8_t bits;
if (nd >= ndu || fd_in == NULL)
return (0);
oaddr = NULL;
bits = 0; /* silence gcc */
for (i = nd; i < ndu; i++) {
b = i / NBBY;
#if BYTE_ORDER == LITTLE_ENDIAN
addr = (char *)fd_in + b;
#else
addr = (char *)fd_in;
if (abi_nfdbits == NFDBITS) {
addr += rounddown(b, sizeof(fd_mask)) +
sizeof(fd_mask) - 1 - b % sizeof(fd_mask);
} else {
addr += rounddown(b, sizeof(uint32_t)) +
sizeof(uint32_t) - 1 - b % sizeof(uint32_t);
}
#endif
if (addr != oaddr) {
res = fubyte(addr);
if (res == -1)
return (EFAULT);
oaddr = addr;
bits = res;
}
if ((bits & (1 << (i % NBBY))) != 0)
return (EBADF);
}
return (0);
}
int
kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou,
fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits)
{
struct filedesc *fdp;
/*
* The magic 2048 here is chosen to be just enough for FD_SETSIZE
* infds with the new FD_SETSIZE of 1024, and more than enough for
* FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE
* of 256.
*/
fd_mask s_selbits[howmany(2048, NFDBITS)];
fd_mask *ibits[3], *obits[3], *selbits, *sbp;
struct timeval rtv;
sbintime_t asbt, precision, rsbt;
u_int nbufbytes, ncpbytes, ncpubytes, nfdbits;
int error, lf, ndu;
if (nd < 0)
return (EINVAL);
fdp = td->td_proc->p_fd;
ndu = nd;
lf = fdp->fd_lastfile;
if (nd > lf + 1)
nd = lf + 1;
error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits);
if (error != 0)
return (error);
error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits);
if (error != 0)