NetBSD/sys/compat/ibcs2/ibcs2_fcntl.c
thorpej 80cc38a1af Fix a partial construction problem that can cause race conditions
between creation of a file descriptor and close(2) when using kernel
assisted threads.  What we do is stick descriptors in the table, but
mark them as "larval".  This causes essentially everything to treat
it as a non-existent descriptor, except for fdalloc(), which sees a
filled slot so that it won't (incorrectly) allocate it again.  When
a descriptor is fully constructed, the code that has constructed it
marks it as "mature" (which actually clears the "larval" flag), and
things continue to work as normal.

While here, gather all the code that gets a descriptor from the table
into a fd_getfile() function, and call it, rather than having the
same (sometimes incorrect) code copied all over the place.
2001-06-14 20:32:41 +00:00

375 lines
10 KiB
C

/* $NetBSD: ibcs2_fcntl.c,v 1.11 2001/06/14 20:32:42 thorpej Exp $ */
/*
* Copyright (c) 1995 Scott Bartram
* All rights reserved.
*
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/filedesc.h>
#include <sys/ioctl.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/malloc.h>
#include <sys/syscallargs.h>
#include <sys/vnode.h>
#include <compat/ibcs2/ibcs2_types.h>
#include <compat/ibcs2/ibcs2_fcntl.h>
#include <compat/ibcs2/ibcs2_unistd.h>
#include <compat/ibcs2/ibcs2_signal.h>
#include <compat/ibcs2/ibcs2_syscallargs.h>
#include <compat/ibcs2/ibcs2_util.h>
static int cvt_o_flags __P((int));
static void cvt_flock2iflock __P((struct flock *, struct ibcs2_flock *));
static void cvt_iflock2flock __P((struct ibcs2_flock *, struct flock *));
static int ioflags2oflags __P((int));
static int oflags2ioflags __P((int));
static int
cvt_o_flags(flags)
int flags;
{
int r = 0;
/* convert mode into NetBSD mode */
if (flags & IBCS2_O_WRONLY) r |= O_WRONLY;
if (flags & IBCS2_O_RDWR) r |= O_RDWR;
if (flags & (IBCS2_O_NDELAY | IBCS2_O_NONBLOCK)) r |= O_NONBLOCK;
if (flags & IBCS2_O_APPEND) r |= O_APPEND;
if (flags & IBCS2_O_SYNC) r |= O_FSYNC;
if (flags & IBCS2_O_CREAT) r |= O_CREAT;
if (flags & IBCS2_O_TRUNC) r |= O_TRUNC;
if (flags & IBCS2_O_EXCL) r |= O_EXCL;
return r;
}
static void
cvt_flock2iflock(flp, iflp)
struct flock *flp;
struct ibcs2_flock *iflp;
{
switch (flp->l_type) {
case F_RDLCK:
iflp->l_type = IBCS2_F_RDLCK;
break;
case F_WRLCK:
iflp->l_type = IBCS2_F_WRLCK;
break;
case F_UNLCK:
iflp->l_type = IBCS2_F_UNLCK;
break;
}
iflp->l_whence = (short)flp->l_whence;
iflp->l_start = (ibcs2_off_t)flp->l_start;
iflp->l_len = (ibcs2_off_t)flp->l_len;
iflp->l_sysid = 0;
iflp->l_pid = (ibcs2_pid_t)flp->l_pid;
}
static void
cvt_iflock2flock(iflp, flp)
struct ibcs2_flock *iflp;
struct flock *flp;
{
flp->l_start = (off_t)iflp->l_start;
flp->l_len = (off_t)iflp->l_len;
flp->l_pid = (pid_t)iflp->l_pid;
switch (iflp->l_type) {
case IBCS2_F_RDLCK:
flp->l_type = F_RDLCK;
break;
case IBCS2_F_WRLCK:
flp->l_type = F_WRLCK;
break;
case IBCS2_F_UNLCK:
flp->l_type = F_UNLCK;
break;
}
flp->l_whence = iflp->l_whence;
}
/* convert iBCS2 mode into NetBSD mode */
static int
ioflags2oflags(flags)
int flags;
{
int r = 0;
if (flags & IBCS2_O_RDONLY) r |= O_RDONLY;
if (flags & IBCS2_O_WRONLY) r |= O_WRONLY;
if (flags & IBCS2_O_RDWR) r |= O_RDWR;
if (flags & IBCS2_O_NDELAY) r |= O_NONBLOCK;
if (flags & IBCS2_O_APPEND) r |= O_APPEND;
if (flags & IBCS2_O_SYNC) r |= O_FSYNC;
if (flags & IBCS2_O_NONBLOCK) r |= O_NONBLOCK;
if (flags & IBCS2_O_CREAT) r |= O_CREAT;
if (flags & IBCS2_O_TRUNC) r |= O_TRUNC;
if (flags & IBCS2_O_EXCL) r |= O_EXCL;
if (flags & IBCS2_O_NOCTTY) r |= O_NOCTTY;
return r;
}
/* convert NetBSD mode into iBCS2 mode */
static int
oflags2ioflags(flags)
int flags;
{
int r = 0;
if (flags & O_RDONLY) r |= IBCS2_O_RDONLY;
if (flags & O_WRONLY) r |= IBCS2_O_WRONLY;
if (flags & O_RDWR) r |= IBCS2_O_RDWR;
if (flags & O_NDELAY) r |= IBCS2_O_NONBLOCK;
if (flags & O_APPEND) r |= IBCS2_O_APPEND;
if (flags & O_FSYNC) r |= IBCS2_O_SYNC;
if (flags & O_NONBLOCK) r |= IBCS2_O_NONBLOCK;
if (flags & O_CREAT) r |= IBCS2_O_CREAT;
if (flags & O_TRUNC) r |= IBCS2_O_TRUNC;
if (flags & O_EXCL) r |= IBCS2_O_EXCL;
if (flags & O_NOCTTY) r |= IBCS2_O_NOCTTY;
return r;
}
int
ibcs2_sys_open(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct ibcs2_sys_open_args /* {
syscallarg(char *) path;
syscallarg(int) flags;
syscallarg(int) mode;
} */ *uap = v;
int noctty = SCARG(uap, flags) & IBCS2_O_NOCTTY;
int ret;
caddr_t sg = stackgap_init(p->p_emul);
SCARG(uap, flags) = cvt_o_flags(SCARG(uap, flags));
if (SCARG(uap, flags) & O_CREAT)
CHECK_ALT_CREAT(p, &sg, SCARG(uap, path));
else
CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
ret = sys_open(p, uap, retval);
if (!ret && !noctty && SESS_LEADER(p) && !(p->p_flag & P_CONTROLT)) {
struct filedesc *fdp = p->p_fd;
struct file *fp;
fp = fd_getfile(fdp, *retval);
/* ignore any error, just give it a try */
if (fp != NULL && fp->f_type == DTYPE_VNODE)
(fp->f_ops->fo_ioctl)(fp, TIOCSCTTY, (caddr_t) 0, p);
}
return ret;
}
int
ibcs2_sys_creat(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct ibcs2_sys_creat_args /* {
syscallarg(char *) path;
syscallarg(int) mode;
} */ *uap = v;
struct sys_open_args cup;
caddr_t sg = stackgap_init(p->p_emul);
CHECK_ALT_CREAT(p, &sg, SCARG(uap, path));
SCARG(&cup, path) = SCARG(uap, path);
SCARG(&cup, mode) = SCARG(uap, mode);
SCARG(&cup, flags) = O_WRONLY | O_CREAT | O_TRUNC;
return sys_open(p, &cup, retval);
}
int
ibcs2_sys_access(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct ibcs2_sys_access_args /* {
syscallarg(char *) path;
syscallarg(int) flags;
} */ *uap = v;
struct sys_access_args cup;
caddr_t sg = stackgap_init(p->p_emul);
CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
SCARG(&cup, path) = SCARG(uap, path);
SCARG(&cup, flags) = SCARG(uap, flags);
return sys_access(p, &cup, retval);
}
int
ibcs2_sys_eaccess(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct ibcs2_sys_eaccess_args /* {
syscallarg(char *) path;
syscallarg(int) flags;
} */ *uap = v;
struct ucred *cred = p->p_ucred;
struct vnode *vp;
int error, flags;
struct nameidata nd;
caddr_t sg = stackgap_init(p->p_emul);
CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_USERSPACE,
SCARG(uap, path), p);
if ((error = namei(&nd)) != 0)
return error;
vp = nd.ni_vp;
/* Flags == 0 means only check for existence. */
if (SCARG(uap, flags)) {
flags = 0;
if (SCARG(uap, flags) & IBCS2_R_OK)
flags |= VREAD;
if (SCARG(uap, flags) & IBCS2_W_OK)
flags |= VWRITE;
if (SCARG(uap, flags) & IBCS2_X_OK)
flags |= VEXEC;
if ((flags & VWRITE) == 0 || (error = vn_writechk(vp)) == 0)
error = VOP_ACCESS(vp, flags, cred, p);
}
vput(vp);
return error;
}
int
ibcs2_sys_fcntl(p, v, retval)
struct proc *p;
void *v;
register_t *retval;
{
struct ibcs2_sys_fcntl_args /* {
syscallarg(int) fd;
syscallarg(int) cmd;
syscallarg(char *) arg;
} */ *uap = v;
int error;
struct sys_fcntl_args fa;
struct flock *flp;
struct ibcs2_flock ifl;
switch(SCARG(uap, cmd)) {
case IBCS2_F_DUPFD:
SCARG(&fa, fd) = SCARG(uap, fd);
SCARG(&fa, cmd) = F_DUPFD;
SCARG(&fa, arg) = SCARG(uap, arg);
return sys_fcntl(p, &fa, retval);
case IBCS2_F_GETFD:
SCARG(&fa, fd) = SCARG(uap, fd);
SCARG(&fa, cmd) = F_GETFD;
SCARG(&fa, arg) = SCARG(uap, arg);
return sys_fcntl(p, &fa, retval);
case IBCS2_F_SETFD:
SCARG(&fa, fd) = SCARG(uap, fd);
SCARG(&fa, cmd) = F_SETFD;
SCARG(&fa, arg) = SCARG(uap, arg);
return sys_fcntl(p, &fa, retval);
case IBCS2_F_GETFL:
SCARG(&fa, fd) = SCARG(uap, fd);
SCARG(&fa, cmd) = F_GETFL;
SCARG(&fa, arg) = SCARG(uap, arg);
error = sys_fcntl(p, &fa, retval);
if (error)
return error;
*retval = oflags2ioflags(*retval);
return error;
case IBCS2_F_SETFL:
SCARG(&fa, fd) = SCARG(uap, fd);
SCARG(&fa, cmd) = F_SETFL;
SCARG(&fa, arg) = (void *)ioflags2oflags((int) SCARG(uap, arg));
return sys_fcntl(p, &fa, retval);
case IBCS2_F_GETLK:
{
caddr_t sg = stackgap_init(p->p_emul);
flp = stackgap_alloc(&sg, sizeof(*flp));
error = copyin((caddr_t)SCARG(uap, arg), (caddr_t)&ifl,
ibcs2_flock_len);
if (error)
return error;
cvt_iflock2flock(&ifl, flp);
SCARG(&fa, fd) = SCARG(uap, fd);
SCARG(&fa, cmd) = F_GETLK;
SCARG(&fa, arg) = (void *)flp;
error = sys_fcntl(p, &fa, retval);
if (error)
return error;
cvt_flock2iflock(flp, &ifl);
return copyout((caddr_t)&ifl, (caddr_t)SCARG(uap, arg),
ibcs2_flock_len);
}
case IBCS2_F_SETLK:
{
caddr_t sg = stackgap_init(p->p_emul);
flp = stackgap_alloc(&sg, sizeof(*flp));
error = copyin((caddr_t)SCARG(uap, arg), (caddr_t)&ifl,
ibcs2_flock_len);
if (error)
return error;
cvt_iflock2flock(&ifl, flp);
SCARG(&fa, fd) = SCARG(uap, fd);
SCARG(&fa, cmd) = F_SETLK;
SCARG(&fa, arg) = (void *)flp;
return sys_fcntl(p, &fa, retval);
}
case IBCS2_F_SETLKW:
{
caddr_t sg = stackgap_init(p->p_emul);
flp = stackgap_alloc(&sg, sizeof(*flp));
error = copyin((caddr_t)SCARG(uap, arg), (caddr_t)&ifl,
ibcs2_flock_len);
if (error)
return error;
cvt_iflock2flock(&ifl, flp);
SCARG(&fa, fd) = SCARG(uap, fd);
SCARG(&fa, cmd) = F_SETLKW;
SCARG(&fa, arg) = (void *)flp;
return sys_fcntl(p, &fa, retval);
}
}
return ENOSYS;
}