freebsd-dev/sys/compat/svr4/svr4_filio.c
John Baldwin 91d5354a2c Locking for the per-process resource limits structure.
- struct plimit includes a mutex to protect a reference count.  The plimit
  structure is treated similarly to struct ucred in that is is always copy
  on write, so having a reference to a structure is sufficient to read from
  it without needing a further lock.
- The proc lock protects the p_limit pointer and must be held while reading
  limits from a process to keep the limit structure from changing out from
  under you while reading from it.
- Various global limits that are ints are not protected by a lock since
  int writes are atomic on all the archs we support and thus a lock
  wouldn't buy us anything.
- All accesses to individual resource limits from a process are abstracted
  behind a simple lim_rlimit(), lim_max(), and lim_cur() API that return
  either an rlimit, or the current or max individual limit of the specified
  resource from a process.
- dosetrlimit() was renamed to kern_setrlimit() to match existing style of
  other similar syscall helper functions.
- The alpha OSF/1 compat layer no longer calls getrlimit() and setrlimit()
  (it didn't used the stackgap when it should have) but uses lim_rlimit()
  and kern_setrlimit() instead.
- The svr4 compat no longer uses the stackgap for resource limits calls,
  but uses lim_rlimit() and kern_setrlimit() instead.
- The ibcs2 compat no longer uses the stackgap for resource limits.  It
  also no longer uses the stackgap for accessing sysctl's for the
  ibcs2_sysconf() syscall but uses kernel_sysctl() instead.  As a result,
  ibcs2_sysconf() no longer needs Giant.
- The p_rlimit macro no longer exists.

Submitted by:	mtm (mostly, I only did a few cleanups and catchups)
Tested on:	i386
Compiled on:	alpha, amd64
2004-02-04 21:52:57 +00:00

257 lines
6.6 KiB
C

/*
* Copyright (c) 1998 Mark Newton
* Copyright (c) 1994 Christos Zoulas
* 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/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/file.h>
#include <sys/filio.h>
#include <sys/lock.h>
#include <sys/signal.h>
#include <sys/filedesc.h>
#include <sys/poll.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/resource.h>
#include <sys/resourcevar.h>
#include <sys/sysproto.h>
#include <compat/svr4/svr4.h>
#include <compat/svr4/svr4_types.h>
#include <compat/svr4/svr4_util.h>
#include <compat/svr4/svr4_signal.h>
#include <compat/svr4/svr4_proto.h>
#include <compat/svr4/svr4_ioctl.h>
#include <compat/svr4/svr4_filio.h>
/*#define GROTTY_READ_HACK*/
int
svr4_sys_poll(td, uap)
struct thread *td;
struct svr4_sys_poll_args *uap;
{
int error;
struct poll_args pa;
struct pollfd *pfd;
int idx = 0, cerr;
u_long siz;
PROC_LOCK(td->td_proc);
if (uap->nfds > lim_cur(td->td_proc, RLIMIT_NOFILE) &&
uap->nfds > FD_SETSIZE) {
PROC_UNLOCK(td->td_proc);
return (EINVAL);
}
PROC_UNLOCK(td->td_proc);
pa.fds = uap->fds;
pa.nfds = uap->nfds;
pa.timeout = uap->timeout;
siz = uap->nfds * sizeof(struct pollfd);
pfd = (struct pollfd *)malloc(siz, M_TEMP, M_WAITOK);
error = poll(td, (struct poll_args *)uap);
if ((cerr = copyin(uap->fds, pfd, siz)) != 0) {
error = cerr;
goto done;
}
for (idx = 0; idx < uap->nfds; idx++) {
/* POLLWRNORM already equals POLLOUT, so we don't worry about that */
if (pfd[idx].revents & (POLLOUT | POLLWRNORM | POLLWRBAND))
pfd[idx].revents |= (POLLOUT | POLLWRNORM | POLLWRBAND);
}
if ((cerr = copyout(pfd, uap->fds, siz)) != 0) {
error = cerr;
goto done; /* yeah, I know it's the next line, but this way I won't
forget to update it if I add more code */
}
done:
free(pfd, M_TEMP);
return error;
}
#if defined(READ_TEST)
int
svr4_sys_read(td, uap)
struct thread *td;
struct svr4_sys_read_args *uap;
{
struct read_args ra;
struct file *fp;
struct socket *so = NULL;
int so_state;
sigset_t sigmask;
int rv;
ra.fd = uap->fd;
ra.buf = uap->buf;
ra.nbyte = uap->nbyte;
if (fget(td, uap->fd, &fp) != 0) {
DPRINTF(("Something fishy with the user-supplied file descriptor...\n"));
return EBADF;
}
if (fp->f_type == DTYPE_SOCKET) {
so = fp->f_data;
DPRINTF(("fd %d is a socket\n", uap->fd));
if (so->so_state & SS_ASYNC) {
DPRINTF(("fd %d is an ASYNC socket!\n", uap->fd));
}
DPRINTF(("Here are its flags: 0x%x\n", so->so_state));
#if defined(GROTTY_READ_HACK)
so_state = so->so_state;
so->so_state &= ~SS_NBIO;
#endif
}
rv = read(td, &ra);
DPRINTF(("svr4_read(%d, 0x%0x, %d) = %d\n",
uap->fd, uap->buf, uap->nbyte, rv));
if (rv == EAGAIN) {
#ifdef DEBUG_SVR4
struct sigacts *ps;
PROC_LOCK(td->td_proc);
ps = td->td_proc->p_sigacts;
mtx_lock(&ps->ps_mtx);
#endif
DPRINTF(("sigmask = 0x%x\n", td->td_sigmask));
DPRINTF(("sigignore = 0x%x\n", ps->ps_sigignore));
DPRINTF(("sigcaught = 0x%x\n", ps->ps_sigcatch));
DPRINTF(("siglist = 0x%x\n", td->td_siglist));
#ifdef DEBUG_SVR4
mtx_unlock(&ps->ps_mtx);
PROC_UNLOCK(td->td_proc);
#endif
}
#if defined(GROTTY_READ_HACK)
if (so) { /* We've already checked to see if this is a socket */
so->so_state = so_state;
}
#endif
fdrop(fp, td);
return(rv);
}
#endif /* READ_TEST */
#if defined(BOGUS)
int
svr4_sys_write(td, uap)
struct thread *td;
struct svr4_sys_write_args *uap;
{
struct write_args wa;
struct file *fp;
int rv;
wa.fd = uap->fd;
wa.buf = uap->buf;
wa.nbyte = uap->nbyte;
rv = write(td, &wa);
DPRINTF(("svr4_write(%d, 0x%0x, %d) = %d\n",
uap->fd, uap->buf, uap->nbyte, rv));
return(rv);
}
#endif /* BOGUS */
int
svr4_fil_ioctl(fp, td, retval, fd, cmd, data)
struct file *fp;
struct thread *td;
register_t *retval;
int fd;
u_long cmd;
caddr_t data;
{
int error;
int num;
struct filedesc *fdp = td->td_proc->p_fd;
*retval = 0;
FILEDESC_LOCK(fdp);
switch (cmd) {
case SVR4_FIOCLEX:
fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
FILEDESC_UNLOCK(fdp);
return 0;
case SVR4_FIONCLEX:
fdp->fd_ofileflags[fd] &= ~UF_EXCLOSE;
FILEDESC_UNLOCK(fdp);
return 0;
case SVR4_FIOGETOWN:
case SVR4_FIOSETOWN:
case SVR4_FIOASYNC:
case SVR4_FIONBIO:
case SVR4_FIONREAD:
FILEDESC_UNLOCK(fdp);
if ((error = copyin(data, &num, sizeof(num))) != 0)
return error;
switch (cmd) {
case SVR4_FIOGETOWN: cmd = FIOGETOWN; break;
case SVR4_FIOSETOWN: cmd = FIOSETOWN; break;
case SVR4_FIOASYNC: cmd = FIOASYNC; break;
case SVR4_FIONBIO: cmd = FIONBIO; break;
case SVR4_FIONREAD: cmd = FIONREAD; break;
}
#ifdef SVR4_DEBUG
if (cmd == FIOASYNC) DPRINTF(("FIOASYNC\n"));
#endif
error = fo_ioctl(fp, cmd, (caddr_t) &num, td->td_ucred, td);
if (error)
return error;
return copyout(&num, data, sizeof(num));
default:
FILEDESC_UNLOCK(fdp);
DPRINTF(("Unknown svr4 filio %lx\n", cmd));
return 0; /* ENOSYS really */
}
}