2005-01-06 23:35:40 +00:00
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/*-
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1994-05-24 10:09:53 +00:00
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* Copyright (c) 1982, 1986, 1989, 1991, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)kern_fork.c 8.6 (Berkeley) 4/8/94
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*/
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2003-06-11 00:56:59 +00:00
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#include <sys/cdefs.h>
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|
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__FBSDID("$FreeBSD$");
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|
1996-01-03 21:42:35 +00:00
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|
#include "opt_ktrace.h"
|
2002-11-20 15:41:25 +00:00
|
|
|
#include "opt_mac.h"
|
1996-01-03 21:42:35 +00:00
|
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|
|
1994-05-24 10:09:53 +00:00
|
|
|
#include <sys/param.h>
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|
|
#include <sys/systm.h>
|
1995-11-12 06:43:28 +00:00
|
|
|
#include <sys/sysproto.h>
|
2003-03-24 21:15:35 +00:00
|
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|
#include <sys/eventhandler.h>
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1994-05-24 10:09:53 +00:00
|
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|
#include <sys/filedesc.h>
|
|
|
|
#include <sys/kernel.h>
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2003-08-15 21:29:06 +00:00
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|
#include <sys/kthread.h>
|
1997-04-26 15:59:50 +00:00
|
|
|
#include <sys/sysctl.h>
|
Rework the witness code to work with sx locks as well as mutexes.
- Introduce lock classes and lock objects. Each lock class specifies a
name and set of flags (or properties) shared by all locks of a given
type. Currently there are three lock classes: spin mutexes, sleep
mutexes, and sx locks. A lock object specifies properties of an
additional lock along with a lock name and all of the extra stuff needed
to make witness work with a given lock. This abstract lock stuff is
defined in sys/lock.h. The lockmgr constants, types, and prototypes have
been moved to sys/lockmgr.h. For temporary backwards compatability,
sys/lock.h includes sys/lockmgr.h.
- Replace proc->p_spinlocks with a per-CPU list, PCPU(spinlocks), of spin
locks held. By making this per-cpu, we do not have to jump through
magic hoops to deal with sched_lock changing ownership during context
switches.
- Replace proc->p_heldmtx, formerly a list of held sleep mutexes, with
proc->p_sleeplocks, which is a list of held sleep locks including sleep
mutexes and sx locks.
- Add helper macros for logging lock events via the KTR_LOCK KTR logging
level so that the log messages are consistent.
- Add some new flags that can be passed to mtx_init():
- MTX_NOWITNESS - specifies that this lock should be ignored by witness.
This is used for the mutex that blocks a sx lock for example.
- MTX_QUIET - this is not new, but you can pass this to mtx_init() now
and no events will be logged for this lock, so that one doesn't have
to change all the individual mtx_lock/unlock() operations.
- All lock objects maintain an initialized flag. Use this flag to export
a mtx_initialized() macro that can be safely called from drivers. Also,
we on longer walk the all_mtx list if MUTEX_DEBUG is defined as witness
performs the corresponding checks using the initialized flag.
- The lock order reversal messages have been improved to output slightly
more accurate file and line numbers.
2001-03-28 09:03:24 +00:00
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|
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#include <sys/lock.h>
|
1994-05-24 10:09:53 +00:00
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#include <sys/malloc.h>
|
2000-10-20 07:58:15 +00:00
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#include <sys/mutex.h>
|
2006-11-06 13:42:10 +00:00
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|
#include <sys/priv.h>
|
1994-05-24 10:09:53 +00:00
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|
#include <sys/proc.h>
|
2002-08-04 01:07:02 +00:00
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|
#include <sys/pioctl.h>
|
1994-05-24 10:09:53 +00:00
|
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|
#include <sys/resourcevar.h>
|
2002-10-12 05:32:24 +00:00
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|
#include <sys/sched.h>
|
2001-01-24 10:47:14 +00:00
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|
#include <sys/syscall.h>
|
2003-08-15 21:29:06 +00:00
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|
#include <sys/vmmeter.h>
|
1994-05-24 10:09:53 +00:00
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|
#include <sys/vnode.h>
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|
#include <sys/acct.h>
|
2000-09-07 01:33:02 +00:00
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|
#include <sys/ktr.h>
|
1994-05-24 10:09:53 +00:00
|
|
|
#include <sys/ktrace.h>
|
1996-09-03 14:25:27 +00:00
|
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|
#include <sys/unistd.h>
|
2001-03-07 02:30:39 +00:00
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|
#include <sys/sx.h>
|
2004-11-27 06:51:39 +00:00
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|
#include <sys/signalvar.h>
|
1994-05-24 10:09:53 +00:00
|
|
|
|
2006-02-02 01:32:58 +00:00
|
|
|
#include <security/audit/audit.h>
|
2006-10-22 11:52:19 +00:00
|
|
|
#include <security/mac/mac_framework.h>
|
2006-02-02 01:32:58 +00:00
|
|
|
|
1994-10-10 01:00:49 +00:00
|
|
|
#include <vm/vm.h>
|
1996-02-23 18:49:25 +00:00
|
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|
#include <vm/pmap.h>
|
|
|
|
#include <vm/vm_map.h>
|
1995-12-07 12:48:31 +00:00
|
|
|
#include <vm/vm_extern.h>
|
2002-03-20 04:09:59 +00:00
|
|
|
#include <vm/uma.h>
|
1994-10-10 01:00:49 +00:00
|
|
|
|
1999-01-26 02:38:12 +00:00
|
|
|
|
1995-11-12 06:43:28 +00:00
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
1995-10-08 00:06:22 +00:00
|
|
|
struct fork_args {
|
1996-08-22 03:50:33 +00:00
|
|
|
int dummy;
|
1995-10-08 00:06:22 +00:00
|
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};
|
1995-11-12 06:43:28 +00:00
|
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|
#endif
|
1995-10-08 00:06:22 +00:00
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
/* ARGSUSED */
|
1994-05-25 09:21:21 +00:00
|
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|
int
|
2001-09-12 08:38:13 +00:00
|
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|
fork(td, uap)
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|
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struct thread *td;
|
1994-05-24 10:09:53 +00:00
|
|
|
struct fork_args *uap;
|
|
|
|
{
|
1999-06-30 15:33:41 +00:00
|
|
|
int error;
|
|
|
|
struct proc *p2;
|
1997-11-20 16:36:17 +00:00
|
|
|
|
2002-10-02 07:44:29 +00:00
|
|
|
error = fork1(td, RFFDG | RFPROC, 0, &p2);
|
1999-06-30 15:33:41 +00:00
|
|
|
if (error == 0) {
|
2001-09-12 08:38:13 +00:00
|
|
|
td->td_retval[0] = p2->p_pid;
|
|
|
|
td->td_retval[1] = 0;
|
1999-06-30 15:33:41 +00:00
|
|
|
}
|
2003-08-15 21:29:06 +00:00
|
|
|
return (error);
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/* ARGSUSED */
|
1994-05-25 09:21:21 +00:00
|
|
|
int
|
2001-09-12 08:38:13 +00:00
|
|
|
vfork(td, uap)
|
|
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|
struct thread *td;
|
1996-02-23 18:49:25 +00:00
|
|
|
struct vfork_args *uap;
|
1994-05-24 10:09:53 +00:00
|
|
|
{
|
1999-06-30 15:33:41 +00:00
|
|
|
int error;
|
|
|
|
struct proc *p2;
|
1997-11-20 16:36:17 +00:00
|
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|
|
2002-10-02 07:44:29 +00:00
|
|
|
error = fork1(td, RFFDG | RFPROC | RFPPWAIT | RFMEM, 0, &p2);
|
1999-06-30 15:33:41 +00:00
|
|
|
if (error == 0) {
|
2001-09-12 08:38:13 +00:00
|
|
|
td->td_retval[0] = p2->p_pid;
|
|
|
|
td->td_retval[1] = 0;
|
1999-06-30 15:33:41 +00:00
|
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|
}
|
2003-08-15 21:29:06 +00:00
|
|
|
return (error);
|
1996-02-23 18:49:25 +00:00
|
|
|
}
|
1994-05-24 10:09:53 +00:00
|
|
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|
1996-02-23 18:49:25 +00:00
|
|
|
int
|
2001-09-12 08:38:13 +00:00
|
|
|
rfork(td, uap)
|
|
|
|
struct thread *td;
|
1996-02-23 18:49:25 +00:00
|
|
|
struct rfork_args *uap;
|
|
|
|
{
|
1999-06-30 15:33:41 +00:00
|
|
|
struct proc *p2;
|
2004-03-04 09:56:29 +00:00
|
|
|
int error;
|
1997-11-20 16:36:17 +00:00
|
|
|
|
2004-03-04 09:56:29 +00:00
|
|
|
/* Don't allow kernel-only flags. */
|
2001-12-19 00:53:23 +00:00
|
|
|
if ((uap->flags & RFKERNELONLY) != 0)
|
|
|
|
return (EINVAL);
|
2004-03-04 09:56:29 +00:00
|
|
|
|
2006-02-06 00:28:50 +00:00
|
|
|
AUDIT_ARG(fflags, uap->flags);
|
2002-10-02 07:44:29 +00:00
|
|
|
error = fork1(td, uap->flags, 0, &p2);
|
1999-06-30 15:33:41 +00:00
|
|
|
if (error == 0) {
|
2001-09-12 08:38:13 +00:00
|
|
|
td->td_retval[0] = p2 ? p2->p_pid : 0;
|
|
|
|
td->td_retval[1] = 0;
|
1999-06-30 15:33:41 +00:00
|
|
|
}
|
2003-08-15 21:29:06 +00:00
|
|
|
return (error);
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
|
|
|
|
2003-08-15 21:29:06 +00:00
|
|
|
int nprocs = 1; /* process 0 */
|
2001-06-11 21:54:19 +00:00
|
|
|
int lastpid = 0;
|
|
|
|
SYSCTL_INT(_kern, OID_AUTO, lastpid, CTLFLAG_RD, &lastpid, 0,
|
2001-02-12 17:59:01 +00:00
|
|
|
"Last used PID");
|
1994-05-24 10:09:53 +00:00
|
|
|
|
1999-12-06 11:13:50 +00:00
|
|
|
/*
|
2001-06-11 21:54:19 +00:00
|
|
|
* Random component to lastpid generation. We mix in a random factor to make
|
1999-12-06 11:13:50 +00:00
|
|
|
* it a little harder to predict. We sanity check the modulus value to avoid
|
|
|
|
* doing it in critical paths. Don't let it be too small or we pointlessly
|
|
|
|
* waste randomness entropy, and don't let it be impossibly large. Using a
|
|
|
|
* modulus that is too big causes a LOT more process table scans and slows
|
|
|
|
* down fork processing as the pidchecked caching is defeated.
|
|
|
|
*/
|
1999-11-28 17:51:09 +00:00
|
|
|
static int randompid = 0;
|
1999-12-06 11:13:50 +00:00
|
|
|
|
|
|
|
static int
|
2000-07-04 11:25:35 +00:00
|
|
|
sysctl_kern_randompid(SYSCTL_HANDLER_ARGS)
|
1999-12-06 11:13:50 +00:00
|
|
|
{
|
2000-12-04 10:23:29 +00:00
|
|
|
int error, pid;
|
|
|
|
|
2004-02-26 00:27:04 +00:00
|
|
|
error = sysctl_wire_old_buffer(req, sizeof(int));
|
|
|
|
if (error != 0)
|
|
|
|
return(error);
|
2002-05-02 15:13:45 +00:00
|
|
|
sx_xlock(&allproc_lock);
|
2000-12-04 10:23:29 +00:00
|
|
|
pid = randompid;
|
|
|
|
error = sysctl_handle_int(oidp, &pid, 0, req);
|
2002-05-02 15:13:45 +00:00
|
|
|
if (error == 0 && req->newptr != NULL) {
|
|
|
|
if (pid < 0 || pid > PID_MAX - 100) /* out of range */
|
|
|
|
pid = PID_MAX - 100;
|
|
|
|
else if (pid < 2) /* NOP */
|
|
|
|
pid = 0;
|
|
|
|
else if (pid < 100) /* Make it reasonable */
|
|
|
|
pid = 100;
|
|
|
|
randompid = pid;
|
|
|
|
}
|
|
|
|
sx_xunlock(&allproc_lock);
|
2000-12-04 10:23:29 +00:00
|
|
|
return (error);
|
1999-12-06 11:13:50 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
SYSCTL_PROC(_kern, OID_AUTO, randompid, CTLTYPE_INT|CTLFLAG_RW,
|
|
|
|
0, 0, sysctl_kern_randompid, "I", "Random PID modulus");
|
1999-11-28 17:51:09 +00:00
|
|
|
|
1997-12-12 04:00:59 +00:00
|
|
|
int
|
2002-10-02 07:44:29 +00:00
|
|
|
fork1(td, flags, pages, procp)
|
2003-08-15 21:29:06 +00:00
|
|
|
struct thread *td;
|
1996-04-17 17:05:08 +00:00
|
|
|
int flags;
|
2002-10-02 07:44:29 +00:00
|
|
|
int pages;
|
2003-08-15 21:29:06 +00:00
|
|
|
struct proc **procp;
|
1994-05-24 10:09:53 +00:00
|
|
|
{
|
2003-08-15 21:29:06 +00:00
|
|
|
struct proc *p1, *p2, *pptr;
|
1994-05-24 10:09:53 +00:00
|
|
|
struct proc *newproc;
|
2003-08-15 21:29:06 +00:00
|
|
|
int ok, trypid;
|
2003-06-19 05:57:25 +00:00
|
|
|
static int curfail, pidchecked = 0;
|
|
|
|
static struct timeval lastfail;
|
2001-03-07 05:21:47 +00:00
|
|
|
struct filedesc *fd;
|
2003-06-02 16:05:32 +00:00
|
|
|
struct filedesc_to_leader *fdtol;
|
2002-02-07 20:58:47 +00:00
|
|
|
struct thread *td2;
|
2002-05-02 15:13:45 +00:00
|
|
|
struct sigacts *newsigacts;
|
2007-11-05 11:36:16 +00:00
|
|
|
struct vmspace *vm2;
|
2002-10-15 00:14:32 +00:00
|
|
|
int error;
|
1997-04-13 01:48:35 +00:00
|
|
|
|
2003-08-15 21:29:06 +00:00
|
|
|
/* Can't copy and clear. */
|
1996-04-17 17:05:08 +00:00
|
|
|
if ((flags & (RFFDG|RFCFDG)) == (RFFDG|RFCFDG))
|
|
|
|
return (EINVAL);
|
1994-05-24 10:09:53 +00:00
|
|
|
|
2003-08-15 21:29:06 +00:00
|
|
|
p1 = td->td_proc;
|
|
|
|
|
1997-04-13 01:48:35 +00:00
|
|
|
/*
|
|
|
|
* Here we don't create a new process, but we divorce
|
|
|
|
* certain parts of a process from itself.
|
|
|
|
*/
|
|
|
|
if ((flags & RFPROC) == 0) {
|
Take out the single-threading code in fork.
After discussions with jeff, alc, (various Ironport people), david Xu,
and mostly Alfred (who found the problem) it has been demonstrated that this
is not needed for our implementations of threads and represents a real
(as in we've seen it happen a lot) deadlock danger.
Several points:
Since forking multiple threads is not allowed, and posix states that
any mutexes owned by othre threads wilol be owned in the child by
phantom threads, and therads shouldn't ba accessing shared structures without
protection, It can be proved that if this leads to the child process accessing
inconsistent data, it's a programming error.
The mode of thread_single() being used in fork() is the wrong one.
It is using SINGLE_NO_EXIT when it should be using SINGLE_BOUNDARY.
Even if this we used, System processes have no need to do it as they have
no userland to get inconsistent.
This commmit first fixes the above bugs to get tehm correct in CVS.
then removes them with #ifdef.
This is so that history contains the corrected version should it
be needed in the future.
This code may be needed if we implement the forkall() syscall from
Solaris. It may be needed for other non-posix thread libraries
at some time in the future, so let the code sit for a short while
while I do some work on it anyhow.
This removes a reproducible lockup in NFS.
It may be argued that maybe doing a fork while holding a vnode lock may
not be the best idea in th efirst place but it shouldn't cause a deadlock.
The removal has been running under soak test for several days now.
This removal should be seriously considered for 7.0 and RELENG_6.
Note. There is code in the core-dumping code that may have a similar problem
with coredumping threaded processes
MFC After: 4 days
2007-10-23 17:54:15 +00:00
|
|
|
if (((p1->p_flag & (P_HADTHREADS|P_SYSTEM)) == P_HADTHREADS) &&
|
2006-03-15 23:24:14 +00:00
|
|
|
(flags & (RFCFDG | RFFDG))) {
|
|
|
|
PROC_LOCK(p1);
|
|
|
|
if (thread_single(SINGLE_BOUNDARY)) {
|
|
|
|
PROC_UNLOCK(p1);
|
|
|
|
return (ERESTART);
|
|
|
|
}
|
|
|
|
PROC_UNLOCK(p1);
|
|
|
|
}
|
|
|
|
|
2007-11-05 11:36:16 +00:00
|
|
|
error = vm_forkproc(td, NULL, NULL, NULL, flags);
|
|
|
|
if (error)
|
|
|
|
goto norfproc_fail;
|
1997-04-13 01:48:35 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Close all file descriptors.
|
|
|
|
*/
|
|
|
|
if (flags & RFCFDG) {
|
|
|
|
struct filedesc *fdtmp;
|
2003-01-01 01:01:14 +00:00
|
|
|
fdtmp = fdinit(td->td_proc->p_fd);
|
|
|
|
fdfree(td);
|
1997-04-13 01:48:35 +00:00
|
|
|
p1->p_fd = fdtmp;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2004-03-04 09:56:29 +00:00
|
|
|
* Unshare file descriptors (from parent).
|
1997-04-13 01:48:35 +00:00
|
|
|
*/
|
2004-12-14 07:20:03 +00:00
|
|
|
if (flags & RFFDG)
|
|
|
|
fdunshare(p1, td);
|
2006-03-15 23:24:14 +00:00
|
|
|
|
2007-11-05 11:36:16 +00:00
|
|
|
norfproc_fail:
|
Take out the single-threading code in fork.
After discussions with jeff, alc, (various Ironport people), david Xu,
and mostly Alfred (who found the problem) it has been demonstrated that this
is not needed for our implementations of threads and represents a real
(as in we've seen it happen a lot) deadlock danger.
Several points:
Since forking multiple threads is not allowed, and posix states that
any mutexes owned by othre threads wilol be owned in the child by
phantom threads, and therads shouldn't ba accessing shared structures without
protection, It can be proved that if this leads to the child process accessing
inconsistent data, it's a programming error.
The mode of thread_single() being used in fork() is the wrong one.
It is using SINGLE_NO_EXIT when it should be using SINGLE_BOUNDARY.
Even if this we used, System processes have no need to do it as they have
no userland to get inconsistent.
This commmit first fixes the above bugs to get tehm correct in CVS.
then removes them with #ifdef.
This is so that history contains the corrected version should it
be needed in the future.
This code may be needed if we implement the forkall() syscall from
Solaris. It may be needed for other non-posix thread libraries
at some time in the future, so let the code sit for a short while
while I do some work on it anyhow.
This removes a reproducible lockup in NFS.
It may be argued that maybe doing a fork while holding a vnode lock may
not be the best idea in th efirst place but it shouldn't cause a deadlock.
The removal has been running under soak test for several days now.
This removal should be seriously considered for 7.0 and RELENG_6.
Note. There is code in the core-dumping code that may have a similar problem
with coredumping threaded processes
MFC After: 4 days
2007-10-23 17:54:15 +00:00
|
|
|
if (((p1->p_flag & (P_HADTHREADS|P_SYSTEM)) == P_HADTHREADS) &&
|
2006-03-15 23:24:14 +00:00
|
|
|
(flags & (RFCFDG | RFFDG))) {
|
|
|
|
PROC_LOCK(p1);
|
|
|
|
thread_single_end();
|
|
|
|
PROC_UNLOCK(p1);
|
|
|
|
}
|
1999-07-03 20:58:44 +00:00
|
|
|
*procp = NULL;
|
2007-11-05 11:36:16 +00:00
|
|
|
return (error);
|
1997-04-13 01:48:35 +00:00
|
|
|
}
|
|
|
|
|
2003-04-01 01:26:20 +00:00
|
|
|
/*
|
2007-11-02 19:40:36 +00:00
|
|
|
* XXX
|
|
|
|
* We did have single-threading code here
|
|
|
|
* however it proved un-needed and caused problems
|
2003-04-01 01:26:20 +00:00
|
|
|
*/
|
Part 1 of KSE-III
The ability to schedule multiple threads per process
(one one cpu) by making ALL system calls optionally asynchronous.
to come: ia64 and power-pc patches, patches for gdb, test program (in tools)
Reviewed by: Almost everyone who counts
(at various times, peter, jhb, matt, alfred, mini, bernd,
and a cast of thousands)
NOTE: this is still Beta code, and contains lots of debugging stuff.
expect slight instability in signals..
2002-06-29 17:26:22 +00:00
|
|
|
|
2002-05-02 15:13:45 +00:00
|
|
|
/* Allocate new proc. */
|
2003-02-19 05:47:46 +00:00
|
|
|
newproc = uma_zalloc(proc_zone, M_WAITOK);
|
2007-11-05 11:36:16 +00:00
|
|
|
if (TAILQ_EMPTY(&newproc->p_threads)) {
|
|
|
|
td2 = thread_alloc();
|
|
|
|
if (td2 == NULL) {
|
|
|
|
error = ENOMEM;
|
|
|
|
goto fail1;
|
|
|
|
}
|
|
|
|
proc_linkup(newproc, td2);
|
|
|
|
sched_newproc(newproc, td2);
|
|
|
|
} else
|
|
|
|
td2 = FIRST_THREAD_IN_PROC(newproc);
|
|
|
|
|
|
|
|
/* Allocate and switch to an alternate kstack if specified. */
|
|
|
|
if (pages != 0) {
|
|
|
|
if (!vm_thread_new_altkstack(td2, pages)) {
|
|
|
|
error = ENOMEM;
|
|
|
|
goto fail1;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
if ((flags & RFMEM) == 0) {
|
|
|
|
vm2 = vmspace_fork(p1->p_vmspace);
|
|
|
|
if (vm2 == NULL) {
|
|
|
|
error = ENOMEM;
|
|
|
|
goto fail1;
|
|
|
|
}
|
|
|
|
} else
|
|
|
|
vm2 = NULL;
|
2002-11-20 15:41:25 +00:00
|
|
|
#ifdef MAC
|
2007-10-24 19:04:04 +00:00
|
|
|
mac_proc_init(newproc);
|
2002-11-20 15:41:25 +00:00
|
|
|
#endif
|
2005-07-01 16:28:32 +00:00
|
|
|
knlist_init(&newproc->p_klist, &newproc->p_mtx, NULL, NULL, NULL);
|
Moderate rewrite of kernel ktrace code to attempt to generally improve
reliability when tracing fast-moving processes or writing traces to
slow file systems by avoiding unbounded queueuing and dropped records.
Record loss was previously possible when the global pool of records
become depleted as a result of record generation outstripping record
commit, which occurred quickly in many common situations.
These changes partially restore the 4.x model of committing ktrace
records at the point of trace generation (synchronous), but maintain
the 5.x deferred record commit behavior (asynchronous) for situations
where entering VFS and sleeping is not possible (i.e., in the
scheduler). Records are now queued per-process as opposed to
globally, with processes responsible for committing records from their
own context as required.
- Eliminate the ktrace worker thread and global record queue, as they
are no longer used. Keep the global free record list, as records
are still used.
- Add a per-process record queue, which will hold any asynchronously
generated records, such as from context switches. This replaces the
global queue as the place to submit asynchronous records to.
- When a record is committed asynchronously, simply queue it to the
process.
- When a record is committed synchronously, first drain any pending
per-process records in order to maintain ordering as best we can.
Currently ordering between competing threads is provided via a global
ktrace_sx, but a per-process flag or lock may be desirable in the
future.
- When a process returns to user space following a system call, trap,
signal delivery, etc, flush any pending records.
- When a process exits, flush any pending records.
- Assert on process tear-down that there are no pending records.
- Slightly abstract the notion of being "in ktrace", which is used to
prevent the recursive generation of records, as well as generating
traces for ktrace events.
Future work here might look at changing the set of events marked for
synchronous and asynchronous record generation, re-balancing queue
depth, timeliness of commit to disk, and so on. I.e., performing a
drain every (n) records.
MFC after: 1 month
Discussed with: jhb
Requested by: Marc Olzheim <marcolz at stack dot nl>
2005-11-13 13:27:44 +00:00
|
|
|
STAILQ_INIT(&newproc->p_ktr);
|
2002-05-02 15:13:45 +00:00
|
|
|
|
2004-03-05 22:37:32 +00:00
|
|
|
/* We have to lock the process tree while we look for a pid. */
|
|
|
|
sx_slock(&proctree_lock);
|
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
/*
|
|
|
|
* Although process entries are dynamically created, we still keep
|
|
|
|
* a global limit on the maximum number we will create. Don't allow
|
2002-07-30 05:37:00 +00:00
|
|
|
* a nonprivileged user to use the last ten processes; don't let root
|
1994-05-24 10:09:53 +00:00
|
|
|
* exceed the limit. The variable nprocs is the current number of
|
|
|
|
* processes, maxproc is the limit.
|
|
|
|
*/
|
2002-05-02 15:13:45 +00:00
|
|
|
sx_xlock(&allproc_lock);
|
2007-06-16 23:41:43 +00:00
|
|
|
if ((nprocs >= maxproc - 10 && priv_check_cred(td->td_ucred,
|
|
|
|
PRIV_MAXPROC, 0) != 0) || nprocs >= maxproc) {
|
2002-10-15 00:14:32 +00:00
|
|
|
error = EAGAIN;
|
|
|
|
goto fail;
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
2002-10-15 00:14:32 +00:00
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
/*
|
|
|
|
* Increment the count of procs running with this uid. Don't allow
|
|
|
|
* a nonprivileged user to exceed their current limit.
|
2006-11-06 13:42:10 +00:00
|
|
|
*
|
|
|
|
* XXXRW: Can we avoid privilege here if it's not needed?
|
1994-05-24 10:09:53 +00:00
|
|
|
*/
|
2007-06-16 23:41:43 +00:00
|
|
|
error = priv_check_cred(td->td_ucred, PRIV_PROC_LIMIT, 0);
|
2006-06-27 11:28:50 +00:00
|
|
|
if (error == 0)
|
|
|
|
ok = chgproccnt(td->td_ucred->cr_ruidinfo, 1, 0);
|
|
|
|
else {
|
|
|
|
PROC_LOCK(p1);
|
|
|
|
ok = chgproccnt(td->td_ucred->cr_ruidinfo, 1,
|
|
|
|
lim_cur(p1, RLIMIT_NPROC));
|
|
|
|
PROC_UNLOCK(p1);
|
|
|
|
}
|
2000-09-14 23:07:39 +00:00
|
|
|
if (!ok) {
|
2002-10-15 00:14:32 +00:00
|
|
|
error = EAGAIN;
|
|
|
|
goto fail;
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
|
|
|
|
1999-06-30 15:33:41 +00:00
|
|
|
/*
|
2002-05-02 15:13:45 +00:00
|
|
|
* Increment the nprocs resource before blocking can occur. There
|
|
|
|
* are hard-limits as to the number of processes that can run.
|
1999-06-30 15:33:41 +00:00
|
|
|
*/
|
2002-05-02 15:13:45 +00:00
|
|
|
nprocs++;
|
1999-07-21 18:02:27 +00:00
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
/*
|
|
|
|
* Find an unused process ID. We remember a range of unused IDs
|
2001-06-11 21:54:19 +00:00
|
|
|
* ready to use (from lastpid+1 through pidchecked-1).
|
2000-09-07 01:33:02 +00:00
|
|
|
*
|
|
|
|
* If RFHIGHPID is set (used during system boot), do not allocate
|
|
|
|
* low-numbered pids.
|
1994-05-24 10:09:53 +00:00
|
|
|
*/
|
2001-06-11 21:54:19 +00:00
|
|
|
trypid = lastpid + 1;
|
2000-09-07 01:33:02 +00:00
|
|
|
if (flags & RFHIGHPID) {
|
2003-08-15 21:29:06 +00:00
|
|
|
if (trypid < 10)
|
2000-09-07 01:33:02 +00:00
|
|
|
trypid = 10;
|
|
|
|
} else {
|
2000-12-04 10:23:29 +00:00
|
|
|
if (randompid)
|
2000-09-07 01:33:02 +00:00
|
|
|
trypid += arc4random() % randompid;
|
|
|
|
}
|
1994-05-24 10:09:53 +00:00
|
|
|
retry:
|
|
|
|
/*
|
|
|
|
* If the process ID prototype has wrapped around,
|
|
|
|
* restart somewhat above 0, as the low-numbered procs
|
|
|
|
* tend to include daemons that don't exit.
|
|
|
|
*/
|
2000-09-07 01:33:02 +00:00
|
|
|
if (trypid >= PID_MAX) {
|
|
|
|
trypid = trypid % PID_MAX;
|
|
|
|
if (trypid < 100)
|
|
|
|
trypid += 100;
|
1994-05-24 10:09:53 +00:00
|
|
|
pidchecked = 0;
|
|
|
|
}
|
2000-09-07 01:33:02 +00:00
|
|
|
if (trypid >= pidchecked) {
|
1994-05-24 10:09:53 +00:00
|
|
|
int doingzomb = 0;
|
|
|
|
|
|
|
|
pidchecked = PID_MAX;
|
|
|
|
/*
|
|
|
|
* Scan the active and zombie procs to check whether this pid
|
|
|
|
* is in use. Remember the lowest pid that's greater
|
2000-09-07 01:33:02 +00:00
|
|
|
* than trypid, so we can avoid checking for a while.
|
1994-05-24 10:09:53 +00:00
|
|
|
*/
|
1999-11-16 10:56:05 +00:00
|
|
|
p2 = LIST_FIRST(&allproc);
|
1994-05-24 10:09:53 +00:00
|
|
|
again:
|
2001-01-24 10:47:14 +00:00
|
|
|
for (; p2 != NULL; p2 = LIST_NEXT(p2, p_list)) {
|
2000-09-07 01:33:02 +00:00
|
|
|
while (p2->p_pid == trypid ||
|
2004-03-05 22:37:32 +00:00
|
|
|
(p2->p_pgrp != NULL &&
|
|
|
|
(p2->p_pgrp->pg_id == trypid ||
|
|
|
|
(p2->p_session != NULL &&
|
|
|
|
p2->p_session->s_sid == trypid)))) {
|
2000-09-07 01:33:02 +00:00
|
|
|
trypid++;
|
2006-08-01 15:30:56 +00:00
|
|
|
if (trypid >= pidchecked)
|
1994-05-24 10:09:53 +00:00
|
|
|
goto retry;
|
|
|
|
}
|
2000-09-07 01:33:02 +00:00
|
|
|
if (p2->p_pid > trypid && pidchecked > p2->p_pid)
|
1994-05-24 10:09:53 +00:00
|
|
|
pidchecked = p2->p_pid;
|
2004-03-05 22:37:32 +00:00
|
|
|
if (p2->p_pgrp != NULL) {
|
|
|
|
if (p2->p_pgrp->pg_id > trypid &&
|
|
|
|
pidchecked > p2->p_pgrp->pg_id)
|
|
|
|
pidchecked = p2->p_pgrp->pg_id;
|
|
|
|
if (p2->p_session != NULL &&
|
|
|
|
p2->p_session->s_sid > trypid &&
|
|
|
|
pidchecked > p2->p_session->s_sid)
|
|
|
|
pidchecked = p2->p_session->s_sid;
|
|
|
|
}
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
|
|
|
if (!doingzomb) {
|
|
|
|
doingzomb = 1;
|
1999-11-16 10:56:05 +00:00
|
|
|
p2 = LIST_FIRST(&zombproc);
|
1994-05-24 10:09:53 +00:00
|
|
|
goto again;
|
|
|
|
}
|
|
|
|
}
|
2004-03-05 22:37:32 +00:00
|
|
|
sx_sunlock(&proctree_lock);
|
1994-05-24 10:09:53 +00:00
|
|
|
|
2000-09-07 01:33:02 +00:00
|
|
|
/*
|
2001-06-11 21:54:19 +00:00
|
|
|
* RFHIGHPID does not mess with the lastpid counter during boot.
|
2000-09-07 01:33:02 +00:00
|
|
|
*/
|
|
|
|
if (flags & RFHIGHPID)
|
|
|
|
pidchecked = 0;
|
|
|
|
else
|
2001-06-11 21:54:19 +00:00
|
|
|
lastpid = trypid;
|
2000-09-07 01:33:02 +00:00
|
|
|
|
2000-11-22 07:42:04 +00:00
|
|
|
p2 = newproc;
|
Part 1 of KSE-III
The ability to schedule multiple threads per process
(one one cpu) by making ALL system calls optionally asynchronous.
to come: ia64 and power-pc patches, patches for gdb, test program (in tools)
Reviewed by: Almost everyone who counts
(at various times, peter, jhb, matt, alfred, mini, bernd,
and a cast of thousands)
NOTE: this is still Beta code, and contains lots of debugging stuff.
expect slight instability in signals..
2002-06-29 17:26:22 +00:00
|
|
|
p2->p_state = PRS_NEW; /* protect against others */
|
2000-11-22 07:42:04 +00:00
|
|
|
p2->p_pid = trypid;
|
Commit 6/14 of sched_lock decomposition.
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.
- Replace the tail-end of fork_exit() with a scheduler specific routine
which can do the appropriate lock manipulations.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:53:34 +00:00
|
|
|
/*
|
|
|
|
* Allow the scheduler to initialize the child.
|
|
|
|
*/
|
|
|
|
thread_lock(td);
|
|
|
|
sched_fork(td, td2);
|
|
|
|
thread_unlock(td);
|
2006-02-06 00:28:50 +00:00
|
|
|
AUDIT_ARG(pid, p2->p_pid);
|
2000-11-22 07:42:04 +00:00
|
|
|
LIST_INSERT_HEAD(&allproc, p2, p_list);
|
|
|
|
LIST_INSERT_HEAD(PIDHASH(p2->p_pid), p2, p_hash);
|
Close race conditions between fork() and [sg]etpriority()'s
PRIO_USER case, possibly also other places that deferences
p_ucred.
In the past, we insert a new process into the allproc list right
after PID allocation, and release the allproc_lock sx. Because
most content in new proc's structure is not yet initialized,
this could lead to undefined result if we do not handle PRS_NEW
with care.
The problem with PRS_NEW state is that it does not provide fine
grained information about how much initialization is done for a
new process. By defination, after PRIO_USER setpriority(), all
processes that belongs to given user should have their nice value
set to the specified value. Therefore, if p_{start,end}copy
section was done for a PRS_NEW process, we can not safely ignore
it because p_nice is in this area. On the other hand, we should
be careful on PRS_NEW processes because we do not allow non-root
users to lower their nice values, and without a successful copy
of the copy section, we can get stale values that is inherted
from the uninitialized area of the process structure.
This commit tries to close the race condition by grabbing proc
mutex *before* we release allproc_lock xlock, and do copy as
well as zero immediately after the allproc_lock xunlock. This
guarantees that the new process would have its p_copy and p_zero
sections, as well as user credential informaion initialized. In
getpriority() case, instead of grabbing PROC_LOCK for a PRS_NEW
process, we just skip the process in question, because it does
not affect the final result of the call, as the p_nice value
would be copied from its parent, and we will see it during
allproc traverse.
Other potential solutions are still under evaluation.
Discussed with: davidxu, jhb, rwatson
PR: kern/108071
MFC after: 2 weeks
2007-02-26 03:38:09 +00:00
|
|
|
|
|
|
|
PROC_LOCK(p2);
|
|
|
|
PROC_LOCK(p1);
|
|
|
|
|
2001-03-28 11:52:56 +00:00
|
|
|
sx_xunlock(&allproc_lock);
|
2000-11-22 07:42:04 +00:00
|
|
|
|
Close race conditions between fork() and [sg]etpriority()'s
PRIO_USER case, possibly also other places that deferences
p_ucred.
In the past, we insert a new process into the allproc list right
after PID allocation, and release the allproc_lock sx. Because
most content in new proc's structure is not yet initialized,
this could lead to undefined result if we do not handle PRS_NEW
with care.
The problem with PRS_NEW state is that it does not provide fine
grained information about how much initialization is done for a
new process. By defination, after PRIO_USER setpriority(), all
processes that belongs to given user should have their nice value
set to the specified value. Therefore, if p_{start,end}copy
section was done for a PRS_NEW process, we can not safely ignore
it because p_nice is in this area. On the other hand, we should
be careful on PRS_NEW processes because we do not allow non-root
users to lower their nice values, and without a successful copy
of the copy section, we can get stale values that is inherted
from the uninitialized area of the process structure.
This commit tries to close the race condition by grabbing proc
mutex *before* we release allproc_lock xlock, and do copy as
well as zero immediately after the allproc_lock xunlock. This
guarantees that the new process would have its p_copy and p_zero
sections, as well as user credential informaion initialized. In
getpriority() case, instead of grabbing PROC_LOCK for a PRS_NEW
process, we just skip the process in question, because it does
not affect the final result of the call, as the p_nice value
would be copied from its parent, and we will see it during
allproc traverse.
Other potential solutions are still under evaluation.
Discussed with: davidxu, jhb, rwatson
PR: kern/108071
MFC after: 2 weeks
2007-02-26 03:38:09 +00:00
|
|
|
bcopy(&p1->p_startcopy, &p2->p_startcopy,
|
|
|
|
__rangeof(struct proc, p_startcopy, p_endcopy));
|
|
|
|
PROC_UNLOCK(p1);
|
|
|
|
|
|
|
|
bzero(&p2->p_startzero,
|
|
|
|
__rangeof(struct proc, p_startzero, p_endzero));
|
|
|
|
|
|
|
|
p2->p_ucred = crhold(td->td_ucred);
|
|
|
|
PROC_UNLOCK(p2);
|
|
|
|
|
2002-05-02 15:13:45 +00:00
|
|
|
/*
|
|
|
|
* Malloc things while we don't hold any locks.
|
|
|
|
*/
|
- Merge struct procsig with struct sigacts.
- Move struct sigacts out of the u-area and malloc() it using the
M_SUBPROC malloc bucket.
- Add a small sigacts_*() API for managing sigacts structures: sigacts_alloc(),
sigacts_free(), sigacts_copy(), sigacts_share(), and sigacts_shared().
- Remove the p_sigignore, p_sigacts, and p_sigcatch macros.
- Add a mutex to struct sigacts that protects all the members of the struct.
- Add sigacts locking.
- Remove Giant from nosys(), kill(), killpg(), and kern_sigaction() now
that sigacts is locked.
- Several in-kernel functions such as psignal(), tdsignal(), trapsignal(),
and thread_stopped() are now MP safe.
Reviewed by: arch@
Approved by: re (rwatson)
2003-05-13 20:36:02 +00:00
|
|
|
if (flags & RFSIGSHARE)
|
2002-05-02 15:13:45 +00:00
|
|
|
newsigacts = NULL;
|
- Merge struct procsig with struct sigacts.
- Move struct sigacts out of the u-area and malloc() it using the
M_SUBPROC malloc bucket.
- Add a small sigacts_*() API for managing sigacts structures: sigacts_alloc(),
sigacts_free(), sigacts_copy(), sigacts_share(), and sigacts_shared().
- Remove the p_sigignore, p_sigacts, and p_sigcatch macros.
- Add a mutex to struct sigacts that protects all the members of the struct.
- Add sigacts locking.
- Remove Giant from nosys(), kill(), killpg(), and kern_sigaction() now
that sigacts is locked.
- Several in-kernel functions such as psignal(), tdsignal(), trapsignal(),
and thread_stopped() are now MP safe.
Reviewed by: arch@
Approved by: re (rwatson)
2003-05-13 20:36:02 +00:00
|
|
|
else
|
|
|
|
newsigacts = sigacts_alloc();
|
2002-05-02 15:13:45 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Copy filedesc.
|
|
|
|
*/
|
2003-06-02 16:05:32 +00:00
|
|
|
if (flags & RFCFDG) {
|
2004-11-08 12:43:23 +00:00
|
|
|
fd = fdinit(p1->p_fd);
|
2003-06-02 16:05:32 +00:00
|
|
|
fdtol = NULL;
|
|
|
|
} else if (flags & RFFDG) {
|
2004-11-08 12:43:23 +00:00
|
|
|
fd = fdcopy(p1->p_fd);
|
2003-06-02 16:05:32 +00:00
|
|
|
fdtol = NULL;
|
|
|
|
} else {
|
2003-01-01 01:01:14 +00:00
|
|
|
fd = fdshare(p1->p_fd);
|
2003-06-02 16:05:32 +00:00
|
|
|
if (p1->p_fdtol == NULL)
|
|
|
|
p1->p_fdtol =
|
|
|
|
filedesc_to_leader_alloc(NULL,
|
|
|
|
NULL,
|
|
|
|
p1->p_leader);
|
|
|
|
if ((flags & RFTHREAD) != 0) {
|
|
|
|
/*
|
|
|
|
* Shared file descriptor table and
|
|
|
|
* shared process leaders.
|
|
|
|
*/
|
|
|
|
fdtol = p1->p_fdtol;
|
Replace custom file descriptor array sleep lock constructed using a mutex
and flags with an sxlock. This leads to a significant and measurable
performance improvement as a result of access to shared locking for
frequent lookup operations, reduced general overhead, and reduced overhead
in the event of contention. All of these are imported for threaded
applications where simultaneous access to a shared file descriptor array
occurs frequently. Kris has reported 2x-4x transaction rate improvements
on 8-core MySQL benchmarks; smaller improvements can be expected for many
workloads as a result of reduced overhead.
- Generally eliminate the distinction between "fast" and regular
acquisisition of the filedesc lock; the plan is that they will now all
be fast. Change all locking instances to either shared or exclusive
locks.
- Correct a bug (pointed out by kib) in fdfree() where previously msleep()
was called without the mutex held; sx_sleep() is now always called with
the sxlock held exclusively.
- Universally hold the struct file lock over changes to struct file,
rather than the filedesc lock or no lock. Always update the f_ops
field last. A further memory barrier is required here in the future
(discussed with jhb).
- Improve locking and reference management in linux_at(), which fails to
properly acquire vnode references before using vnode pointers. Annotate
improper use of vn_fullpath(), which will be replaced at a future date.
In fcntl(), we conservatively acquire an exclusive lock, even though in
some cases a shared lock may be sufficient, which should be revisited.
The dropping of the filedesc lock in fdgrowtable() is no longer required
as the sxlock can be held over the sleep operation; we should consider
removing that (pointed out by attilio).
Tested by: kris
Discussed with: jhb, kris, attilio, jeff
2007-04-04 09:11:34 +00:00
|
|
|
FILEDESC_XLOCK(p1->p_fd);
|
2003-06-02 16:05:32 +00:00
|
|
|
fdtol->fdl_refcount++;
|
Replace custom file descriptor array sleep lock constructed using a mutex
and flags with an sxlock. This leads to a significant and measurable
performance improvement as a result of access to shared locking for
frequent lookup operations, reduced general overhead, and reduced overhead
in the event of contention. All of these are imported for threaded
applications where simultaneous access to a shared file descriptor array
occurs frequently. Kris has reported 2x-4x transaction rate improvements
on 8-core MySQL benchmarks; smaller improvements can be expected for many
workloads as a result of reduced overhead.
- Generally eliminate the distinction between "fast" and regular
acquisisition of the filedesc lock; the plan is that they will now all
be fast. Change all locking instances to either shared or exclusive
locks.
- Correct a bug (pointed out by kib) in fdfree() where previously msleep()
was called without the mutex held; sx_sleep() is now always called with
the sxlock held exclusively.
- Universally hold the struct file lock over changes to struct file,
rather than the filedesc lock or no lock. Always update the f_ops
field last. A further memory barrier is required here in the future
(discussed with jhb).
- Improve locking and reference management in linux_at(), which fails to
properly acquire vnode references before using vnode pointers. Annotate
improper use of vn_fullpath(), which will be replaced at a future date.
In fcntl(), we conservatively acquire an exclusive lock, even though in
some cases a shared lock may be sufficient, which should be revisited.
The dropping of the filedesc lock in fdgrowtable() is no longer required
as the sxlock can be held over the sleep operation; we should consider
removing that (pointed out by attilio).
Tested by: kris
Discussed with: jhb, kris, attilio, jeff
2007-04-04 09:11:34 +00:00
|
|
|
FILEDESC_XUNLOCK(p1->p_fd);
|
2003-06-02 16:05:32 +00:00
|
|
|
} else {
|
|
|
|
/*
|
|
|
|
* Shared file descriptor table, and
|
|
|
|
* different process leaders
|
|
|
|
*/
|
|
|
|
fdtol = filedesc_to_leader_alloc(p1->p_fdtol,
|
|
|
|
p1->p_fd,
|
|
|
|
p2);
|
|
|
|
}
|
|
|
|
}
|
1994-05-24 10:09:53 +00:00
|
|
|
/*
|
|
|
|
* Make a proc table entry for the new process.
|
|
|
|
* Start by zeroing the section of proc that is zero-initialized,
|
|
|
|
* then copy the section that is copied directly from the parent.
|
|
|
|
*/
|
2002-10-02 07:44:29 +00:00
|
|
|
|
2003-05-01 21:16:38 +00:00
|
|
|
PROC_LOCK(p2);
|
|
|
|
PROC_LOCK(p1);
|
|
|
|
|
2002-02-07 20:58:47 +00:00
|
|
|
bzero(&td2->td_startzero,
|
2004-11-20 23:00:59 +00:00
|
|
|
__rangeof(struct thread, td_startzero, td_endzero));
|
2001-09-12 08:38:13 +00:00
|
|
|
|
2002-02-07 20:58:47 +00:00
|
|
|
bcopy(&td->td_startcopy, &td2->td_startcopy,
|
2004-11-20 23:00:59 +00:00
|
|
|
__rangeof(struct thread, td_startcopy, td_endcopy));
|
1994-05-24 10:09:53 +00:00
|
|
|
|
2004-01-03 02:02:26 +00:00
|
|
|
td2->td_sigstk = td->td_sigstk;
|
2005-04-20 13:14:52 +00:00
|
|
|
td2->td_sigmask = td->td_sigmask;
|
2007-09-17 05:31:39 +00:00
|
|
|
td2->td_flags = TDF_INMEM;
|
2004-01-03 02:02:26 +00:00
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
/*
|
|
|
|
* Duplicate sub-structures as needed.
|
|
|
|
* Increase reference counts on shared objects.
|
|
|
|
*/
|
2007-09-17 05:31:39 +00:00
|
|
|
p2->p_flag = P_INMEM;
|
2007-09-21 04:10:23 +00:00
|
|
|
p2->p_swtick = ticks;
|
2003-04-22 20:54:04 +00:00
|
|
|
if (p1->p_flag & P_PROFIL)
|
|
|
|
startprofclock(p2);
|
2006-10-26 21:42:22 +00:00
|
|
|
td2->td_ucred = crhold(p2->p_ucred);
|
2002-03-27 21:36:18 +00:00
|
|
|
pargs_hold(p2->p_args);
|
1999-11-16 20:31:58 +00:00
|
|
|
|
1998-12-19 02:55:34 +00:00
|
|
|
if (flags & RFSIGSHARE) {
|
- Merge struct procsig with struct sigacts.
- Move struct sigacts out of the u-area and malloc() it using the
M_SUBPROC malloc bucket.
- Add a small sigacts_*() API for managing sigacts structures: sigacts_alloc(),
sigacts_free(), sigacts_copy(), sigacts_share(), and sigacts_shared().
- Remove the p_sigignore, p_sigacts, and p_sigcatch macros.
- Add a mutex to struct sigacts that protects all the members of the struct.
- Add sigacts locking.
- Remove Giant from nosys(), kill(), killpg(), and kern_sigaction() now
that sigacts is locked.
- Several in-kernel functions such as psignal(), tdsignal(), trapsignal(),
and thread_stopped() are now MP safe.
Reviewed by: arch@
Approved by: re (rwatson)
2003-05-13 20:36:02 +00:00
|
|
|
p2->p_sigacts = sigacts_hold(p1->p_sigacts);
|
1998-12-19 02:55:34 +00:00
|
|
|
} else {
|
- Merge struct procsig with struct sigacts.
- Move struct sigacts out of the u-area and malloc() it using the
M_SUBPROC malloc bucket.
- Add a small sigacts_*() API for managing sigacts structures: sigacts_alloc(),
sigacts_free(), sigacts_copy(), sigacts_share(), and sigacts_shared().
- Remove the p_sigignore, p_sigacts, and p_sigcatch macros.
- Add a mutex to struct sigacts that protects all the members of the struct.
- Add sigacts locking.
- Remove Giant from nosys(), kill(), killpg(), and kern_sigaction() now
that sigacts is locked.
- Several in-kernel functions such as psignal(), tdsignal(), trapsignal(),
and thread_stopped() are now MP safe.
Reviewed by: arch@
Approved by: re (rwatson)
2003-05-13 20:36:02 +00:00
|
|
|
sigacts_copy(newsigacts, p1->p_sigacts);
|
|
|
|
p2->p_sigacts = newsigacts;
|
1998-12-19 02:55:34 +00:00
|
|
|
}
|
1999-03-02 00:28:09 +00:00
|
|
|
if (flags & RFLINUXTHPN)
|
1998-12-19 02:55:34 +00:00
|
|
|
p2->p_sigparent = SIGUSR1;
|
1999-03-02 00:28:09 +00:00
|
|
|
else
|
|
|
|
p2->p_sigparent = SIGCHLD;
|
1999-01-26 02:38:12 +00:00
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
p2->p_textvp = p1->p_textvp;
|
2001-03-07 05:21:47 +00:00
|
|
|
p2->p_fd = fd;
|
2003-06-02 16:05:32 +00:00
|
|
|
p2->p_fdtol = fdtol;
|
1996-02-23 18:49:25 +00:00
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
/*
|
2004-03-04 09:56:29 +00:00
|
|
|
* p_limit is copy-on-write. Bump its refcount.
|
1994-05-24 10:09:53 +00:00
|
|
|
*/
|
2007-06-01 01:12:45 +00:00
|
|
|
lim_fork(p1, p2);
|
2004-11-20 02:28:48 +00:00
|
|
|
|
|
|
|
pstats_fork(p1->p_stats, p2->p_stats);
|
|
|
|
|
2004-10-01 05:01:29 +00:00
|
|
|
PROC_UNLOCK(p1);
|
2004-10-06 23:53:49 +00:00
|
|
|
PROC_UNLOCK(p2);
|
1994-05-24 10:09:53 +00:00
|
|
|
|
2004-03-08 00:32:34 +00:00
|
|
|
/* Bump references to the text vnode (for procfs) */
|
|
|
|
if (p2->p_textvp)
|
|
|
|
vref(p2->p_textvp);
|
|
|
|
|
2002-10-15 00:14:32 +00:00
|
|
|
/*
|
2004-03-04 09:56:29 +00:00
|
|
|
* Set up linkage for kernel based threading.
|
2002-10-15 00:14:32 +00:00
|
|
|
*/
|
2004-03-04 09:56:29 +00:00
|
|
|
if ((flags & RFTHREAD) != 0) {
|
2002-10-15 00:14:32 +00:00
|
|
|
mtx_lock(&ppeers_lock);
|
|
|
|
p2->p_peers = p1->p_peers;
|
|
|
|
p1->p_peers = p2;
|
|
|
|
p2->p_leader = p1->p_leader;
|
|
|
|
mtx_unlock(&ppeers_lock);
|
|
|
|
PROC_LOCK(p1->p_leader);
|
|
|
|
if ((p1->p_leader->p_flag & P_WEXIT) != 0) {
|
|
|
|
PROC_UNLOCK(p1->p_leader);
|
|
|
|
/*
|
|
|
|
* The task leader is exiting, so process p1 is
|
|
|
|
* going to be killed shortly. Since p1 obviously
|
|
|
|
* isn't dead yet, we know that the leader is either
|
|
|
|
* sending SIGKILL's to all the processes in this
|
|
|
|
* task or is sleeping waiting for all the peers to
|
|
|
|
* exit. We let p1 complete the fork, but we need
|
|
|
|
* to go ahead and kill the new process p2 since
|
|
|
|
* the task leader may not get a chance to send
|
|
|
|
* SIGKILL to it. We leave it on the list so that
|
|
|
|
* the task leader will wait for this new process
|
|
|
|
* to commit suicide.
|
|
|
|
*/
|
|
|
|
PROC_LOCK(p2);
|
|
|
|
psignal(p2, SIGKILL);
|
|
|
|
PROC_UNLOCK(p2);
|
2002-11-18 14:23:21 +00:00
|
|
|
} else
|
|
|
|
PROC_UNLOCK(p1->p_leader);
|
2002-10-15 00:14:32 +00:00
|
|
|
} else {
|
|
|
|
p2->p_peers = NULL;
|
|
|
|
p2->p_leader = p2;
|
|
|
|
}
|
|
|
|
|
2002-05-02 15:13:45 +00:00
|
|
|
sx_xlock(&proctree_lock);
|
|
|
|
PGRP_LOCK(p1->p_pgrp);
|
|
|
|
PROC_LOCK(p2);
|
|
|
|
PROC_LOCK(p1);
|
|
|
|
|
1997-02-17 10:58:46 +00:00
|
|
|
/*
|
2003-04-22 20:54:04 +00:00
|
|
|
* Preserve some more flags in subprocess. P_PROFIL has already
|
1997-11-20 16:36:17 +00:00
|
|
|
* been preserved.
|
1997-02-17 10:58:46 +00:00
|
|
|
*/
|
2004-01-03 02:02:26 +00:00
|
|
|
p2->p_flag |= p1->p_flag & P_SUGID;
|
|
|
|
td2->td_pflags |= td->td_pflags & TDP_ALTSTACK;
|
2002-02-23 11:12:57 +00:00
|
|
|
SESS_LOCK(p1->p_session);
|
1994-05-24 10:09:53 +00:00
|
|
|
if (p1->p_session->s_ttyvp != NULL && p1->p_flag & P_CONTROLT)
|
|
|
|
p2->p_flag |= P_CONTROLT;
|
2002-02-23 11:12:57 +00:00
|
|
|
SESS_UNLOCK(p1->p_session);
|
1996-04-17 17:05:08 +00:00
|
|
|
if (flags & RFPPWAIT)
|
1994-05-24 10:09:53 +00:00
|
|
|
p2->p_flag |= P_PPWAIT;
|
1997-11-20 16:36:17 +00:00
|
|
|
|
2004-01-09 23:42:36 +00:00
|
|
|
p2->p_pgrp = p1->p_pgrp;
|
1996-03-11 06:05:03 +00:00
|
|
|
LIST_INSERT_AFTER(p1, p2, p_pglist);
|
2002-04-02 17:12:06 +00:00
|
|
|
PGRP_UNLOCK(p1->p_pgrp);
|
1996-03-11 06:05:03 +00:00
|
|
|
LIST_INIT(&p2->p_children);
|
|
|
|
|
2003-08-19 17:51:11 +00:00
|
|
|
callout_init(&p2->p_itcallout, CALLOUT_MPSAFE);
|
2000-11-27 22:52:31 +00:00
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
#ifdef KTRACE
|
|
|
|
/*
|
2002-06-07 05:42:25 +00:00
|
|
|
* Copy traceflag and tracefile if enabled.
|
1994-05-24 10:09:53 +00:00
|
|
|
*/
|
2002-06-07 05:42:25 +00:00
|
|
|
mtx_lock(&ktrace_mtx);
|
2003-03-13 18:24:22 +00:00
|
|
|
KASSERT(p2->p_tracevp == NULL, ("new process has a ktrace vnode"));
|
2002-06-07 05:42:25 +00:00
|
|
|
if (p1->p_traceflag & KTRFAC_INHERIT) {
|
1994-05-24 10:09:53 +00:00
|
|
|
p2->p_traceflag = p1->p_traceflag;
|
2003-03-13 18:24:22 +00:00
|
|
|
if ((p2->p_tracevp = p1->p_tracevp) != NULL) {
|
|
|
|
VREF(p2->p_tracevp);
|
|
|
|
KASSERT(p1->p_tracecred != NULL,
|
|
|
|
("ktrace vnode with no cred"));
|
|
|
|
p2->p_tracecred = crhold(p1->p_tracecred);
|
|
|
|
}
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
2002-06-07 05:42:25 +00:00
|
|
|
mtx_unlock(&ktrace_mtx);
|
1994-05-24 10:09:53 +00:00
|
|
|
#endif
|
|
|
|
|
2002-08-07 11:31:45 +00:00
|
|
|
/*
|
|
|
|
* If PF_FORK is set, the child process inherits the
|
|
|
|
* procfs ioctl flags from its parent.
|
|
|
|
*/
|
|
|
|
if (p1->p_pfsflags & PF_FORK) {
|
|
|
|
p2->p_stops = p1->p_stops;
|
|
|
|
p2->p_pfsflags = p1->p_pfsflags;
|
|
|
|
}
|
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
/*
|
|
|
|
* This begins the section where we must prevent the parent
|
2004-10-06 23:53:49 +00:00
|
|
|
* from being swapped.
|
1994-05-24 10:09:53 +00:00
|
|
|
*/
|
2004-10-06 23:53:49 +00:00
|
|
|
_PHOLD(p1);
|
2001-03-07 02:30:39 +00:00
|
|
|
PROC_UNLOCK(p1);
|
2002-05-02 15:13:45 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Attach the new process to its parent.
|
|
|
|
*
|
|
|
|
* If RFNOWAIT is set, the newly created process becomes a child
|
|
|
|
* of init. This effectively disassociates the child from the
|
|
|
|
* parent.
|
|
|
|
*/
|
|
|
|
if (flags & RFNOWAIT)
|
|
|
|
pptr = initproc;
|
|
|
|
else
|
|
|
|
pptr = p1;
|
|
|
|
p2->p_pptr = pptr;
|
|
|
|
LIST_INSERT_HEAD(&pptr->p_children, p2, p_sibling);
|
|
|
|
sx_xunlock(&proctree_lock);
|
|
|
|
|
2003-04-17 22:24:59 +00:00
|
|
|
/* Inform accounting that we have forked. */
|
|
|
|
p2->p_acflag = AFORK;
|
|
|
|
PROC_UNLOCK(p2);
|
|
|
|
|
1996-02-23 18:49:25 +00:00
|
|
|
/*
|
1997-04-07 07:16:06 +00:00
|
|
|
* Finish creating the child process. It will return via a different
|
|
|
|
* execution path later. (ie: directly into user mode)
|
1996-02-23 18:49:25 +00:00
|
|
|
*/
|
2007-11-05 11:36:16 +00:00
|
|
|
vm_forkproc(td, p2, td2, vm2, flags);
|
1994-05-24 10:09:53 +00:00
|
|
|
|
2001-01-23 14:32:01 +00:00
|
|
|
if (flags == (RFFDG | RFPROC)) {
|
2007-06-10 21:59:14 +00:00
|
|
|
PCPU_INC(cnt.v_forks);
|
|
|
|
PCPU_ADD(cnt.v_forkpages, p2->p_vmspace->vm_dsize +
|
2004-09-03 05:11:32 +00:00
|
|
|
p2->p_vmspace->vm_ssize);
|
2001-01-23 14:32:01 +00:00
|
|
|
} else if (flags == (RFFDG | RFPROC | RFPPWAIT | RFMEM)) {
|
2007-06-10 21:59:14 +00:00
|
|
|
PCPU_INC(cnt.v_vforks);
|
|
|
|
PCPU_ADD(cnt.v_vforkpages, p2->p_vmspace->vm_dsize +
|
2004-09-03 05:11:32 +00:00
|
|
|
p2->p_vmspace->vm_ssize);
|
2001-01-23 14:32:01 +00:00
|
|
|
} else if (p1 == &proc0) {
|
2007-06-10 21:59:14 +00:00
|
|
|
PCPU_INC(cnt.v_kthreads);
|
|
|
|
PCPU_ADD(cnt.v_kthreadpages, p2->p_vmspace->vm_dsize +
|
2004-09-03 05:11:32 +00:00
|
|
|
p2->p_vmspace->vm_ssize);
|
2001-01-23 14:32:01 +00:00
|
|
|
} else {
|
2007-06-10 21:59:14 +00:00
|
|
|
PCPU_INC(cnt.v_rforks);
|
|
|
|
PCPU_ADD(cnt.v_rforkpages, p2->p_vmspace->vm_dsize +
|
2004-09-03 05:11:32 +00:00
|
|
|
p2->p_vmspace->vm_ssize);
|
2001-01-23 14:32:01 +00:00
|
|
|
}
|
|
|
|
|
1996-08-19 02:28:24 +00:00
|
|
|
/*
|
1999-04-17 08:36:07 +00:00
|
|
|
* Both processes are set up, now check if any loadable modules want
|
1996-08-22 03:50:33 +00:00
|
|
|
* to adjust anything.
|
|
|
|
* What if they have an error? XXX
|
1996-08-19 02:28:24 +00:00
|
|
|
*/
|
2003-03-24 21:15:35 +00:00
|
|
|
EVENTHANDLER_INVOKE(process_fork, p1, p2, flags);
|
1996-08-19 02:28:24 +00:00
|
|
|
|
2004-02-05 21:01:37 +00:00
|
|
|
/*
|
|
|
|
* Set the child start time and mark the process as being complete.
|
|
|
|
*/
|
|
|
|
microuptime(&p2->p_stats->p_start);
|
Commit 6/14 of sched_lock decomposition.
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.
- Replace the tail-end of fork_exit() with a scheduler specific routine
which can do the appropriate lock manipulations.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:53:34 +00:00
|
|
|
PROC_SLOCK(p2);
|
2004-02-05 21:01:37 +00:00
|
|
|
p2->p_state = PRS_NORMAL;
|
Commit 6/14 of sched_lock decomposition.
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.
- Replace the tail-end of fork_exit() with a scheduler specific routine
which can do the appropriate lock manipulations.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:53:34 +00:00
|
|
|
PROC_SUNLOCK(p2);
|
2004-02-05 21:01:37 +00:00
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
/*
|
2000-09-07 01:33:02 +00:00
|
|
|
* If RFSTOPPED not requested, make child runnable and add to
|
|
|
|
* run queue.
|
1994-05-24 10:09:53 +00:00
|
|
|
*/
|
2000-09-07 01:33:02 +00:00
|
|
|
if ((flags & RFSTOPPED) == 0) {
|
Commit 6/14 of sched_lock decomposition.
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.
- Replace the tail-end of fork_exit() with a scheduler specific routine
which can do the appropriate lock manipulations.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:53:34 +00:00
|
|
|
thread_lock(td2);
|
2002-09-11 08:13:56 +00:00
|
|
|
TD_SET_CAN_RUN(td2);
|
2007-01-23 08:46:51 +00:00
|
|
|
sched_add(td2, SRQ_BORING);
|
Commit 6/14 of sched_lock decomposition.
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.
- Replace the tail-end of fork_exit() with a scheduler specific routine
which can do the appropriate lock manipulations.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:53:34 +00:00
|
|
|
thread_unlock(td2);
|
2000-09-07 01:33:02 +00:00
|
|
|
}
|
1994-05-24 10:09:53 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Now can be swapped.
|
|
|
|
*/
|
2001-03-07 02:30:39 +00:00
|
|
|
PROC_LOCK(p1);
|
|
|
|
_PRELE(p1);
|
1994-05-24 10:09:53 +00:00
|
|
|
|
2000-04-16 18:53:38 +00:00
|
|
|
/*
|
2003-08-15 21:29:06 +00:00
|
|
|
* Tell any interested parties about the new process.
|
2000-04-16 18:53:38 +00:00
|
|
|
*/
|
2004-08-15 06:24:42 +00:00
|
|
|
KNOTE_LOCKED(&p1->p_klist, NOTE_FORK | p2->p_pid);
|
2003-08-15 21:29:06 +00:00
|
|
|
|
2001-03-07 02:30:39 +00:00
|
|
|
PROC_UNLOCK(p1);
|
2000-04-16 18:53:38 +00:00
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
/*
|
|
|
|
* Preserve synchronization semantics of vfork. If waiting for
|
|
|
|
* child to exec or exit, set P_PPWAIT on child, and sleep on our
|
|
|
|
* proc (in case of exit).
|
|
|
|
*/
|
2001-03-07 02:30:39 +00:00
|
|
|
PROC_LOCK(p2);
|
1996-04-17 17:05:08 +00:00
|
|
|
while (p2->p_flag & P_PPWAIT)
|
2001-03-07 02:30:39 +00:00
|
|
|
msleep(p1, &p2->p_mtx, PWAIT, "ppwait", 0);
|
|
|
|
PROC_UNLOCK(p2);
|
1994-05-24 10:09:53 +00:00
|
|
|
|
|
|
|
/*
|
1999-06-30 15:33:41 +00:00
|
|
|
* Return child proc pointer to parent.
|
1994-05-24 10:09:53 +00:00
|
|
|
*/
|
1999-06-30 15:33:41 +00:00
|
|
|
*procp = p2;
|
1994-05-24 10:09:53 +00:00
|
|
|
return (0);
|
2002-10-15 00:14:32 +00:00
|
|
|
fail:
|
2004-03-05 22:37:32 +00:00
|
|
|
sx_sunlock(&proctree_lock);
|
2003-06-19 05:57:25 +00:00
|
|
|
if (ppsratecheck(&lastfail, &curfail, 1))
|
|
|
|
printf("maxproc limit exceeded by uid %i, please see tuning(7) and login.conf(5).\n",
|
2006-06-27 11:28:50 +00:00
|
|
|
td->td_ucred->cr_ruid);
|
2002-10-15 00:14:32 +00:00
|
|
|
sx_xunlock(&allproc_lock);
|
2004-01-25 18:42:18 +00:00
|
|
|
#ifdef MAC
|
2007-10-24 19:04:04 +00:00
|
|
|
mac_proc_destroy(newproc);
|
2004-01-25 18:42:18 +00:00
|
|
|
#endif
|
2007-11-05 11:36:16 +00:00
|
|
|
fail1:
|
2002-10-15 00:14:32 +00:00
|
|
|
uma_zfree(proc_zone, newproc);
|
2007-02-27 17:22:30 +00:00
|
|
|
pause("fork", hz / 2);
|
2002-10-15 00:14:32 +00:00
|
|
|
return (error);
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
1996-08-19 02:28:24 +00:00
|
|
|
|
2001-01-24 10:47:14 +00:00
|
|
|
/*
|
|
|
|
* Handle the return of a child process from fork1(). This function
|
|
|
|
* is called from the MD fork_trampoline() entry point.
|
|
|
|
*/
|
|
|
|
void
|
|
|
|
fork_exit(callout, arg, frame)
|
2001-01-26 23:51:41 +00:00
|
|
|
void (*callout)(void *, struct trapframe *);
|
2001-01-24 10:47:14 +00:00
|
|
|
void *arg;
|
2001-01-24 21:59:25 +00:00
|
|
|
struct trapframe *frame;
|
2001-01-24 10:47:14 +00:00
|
|
|
{
|
2002-12-10 02:33:45 +00:00
|
|
|
struct proc *p;
|
2003-08-15 21:29:06 +00:00
|
|
|
struct thread *td;
|
2007-06-12 07:47:09 +00:00
|
|
|
struct thread *dtd;
|
2003-08-15 21:29:06 +00:00
|
|
|
|
2002-12-10 02:33:45 +00:00
|
|
|
td = curthread;
|
|
|
|
p = td->td_proc;
|
2004-02-05 21:01:37 +00:00
|
|
|
KASSERT(p->p_state == PRS_NORMAL, ("executing process is still new"));
|
2003-08-15 21:29:06 +00:00
|
|
|
|
2004-08-09 18:21:12 +00:00
|
|
|
CTR4(KTR_PROC, "fork_exit: new thread %p (kse %p, pid %d, %s)",
|
2007-11-14 06:51:33 +00:00
|
|
|
td, td->td_sched, p->p_pid, td->td_name);
|
2004-07-27 03:46:31 +00:00
|
|
|
|
Commit 6/14 of sched_lock decomposition.
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.
- Replace the tail-end of fork_exit() with a scheduler specific routine
which can do the appropriate lock manipulations.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:53:34 +00:00
|
|
|
sched_fork_exit(td);
|
2007-06-12 07:47:09 +00:00
|
|
|
/*
|
|
|
|
* Processes normally resume in mi_switch() after being
|
|
|
|
* cpu_switch()'ed to, but when children start up they arrive here
|
|
|
|
* instead, so we must do much the same things as mi_switch() would.
|
|
|
|
*/
|
|
|
|
if ((dtd = PCPU_GET(deadthread))) {
|
|
|
|
PCPU_SET(deadthread, NULL);
|
|
|
|
thread_stash(dtd);
|
|
|
|
}
|
|
|
|
thread_unlock(td);
|
|
|
|
|
2001-01-24 10:47:14 +00:00
|
|
|
/*
|
|
|
|
* cpu_set_fork_handler intercepts this function call to
|
2003-08-15 21:29:06 +00:00
|
|
|
* have this call a non-return function to stay in kernel mode.
|
|
|
|
* initproc has its own fork handler, but it does return.
|
|
|
|
*/
|
2001-02-20 05:26:15 +00:00
|
|
|
KASSERT(callout != NULL, ("NULL callout in fork_exit"));
|
2001-01-26 23:51:41 +00:00
|
|
|
callout(arg, frame);
|
2001-01-24 10:47:14 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Check if a kernel thread misbehaved and returned from its main
|
|
|
|
* function.
|
|
|
|
*/
|
|
|
|
if (p->p_flag & P_KTHREAD) {
|
|
|
|
printf("Kernel thread \"%s\" (pid %d) exited prematurely.\n",
|
2007-11-14 06:51:33 +00:00
|
|
|
td->td_name, p->p_pid);
|
2007-10-20 23:23:23 +00:00
|
|
|
kproc_exit(0);
|
2001-01-24 10:47:14 +00:00
|
|
|
}
|
|
|
|
mtx_assert(&Giant, MA_NOTOWNED);
|
2006-08-15 12:10:57 +00:00
|
|
|
|
|
|
|
EVENTHANDLER_INVOKE(schedtail, p);
|
2001-01-24 10:47:14 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Simplified back end of syscall(), used when returning from fork()
|
|
|
|
* directly into user mode. Giant is not held on entry, and must not
|
|
|
|
* be held on return. This function is passed in to fork_exit() as the
|
|
|
|
* first parameter and is called when returning to a new userland process.
|
|
|
|
*/
|
|
|
|
void
|
2001-09-12 08:38:13 +00:00
|
|
|
fork_return(td, frame)
|
|
|
|
struct thread *td;
|
2001-01-24 10:47:14 +00:00
|
|
|
struct trapframe *frame;
|
|
|
|
{
|
|
|
|
|
2006-02-08 08:09:17 +00:00
|
|
|
userret(td, frame);
|
2001-01-24 10:47:14 +00:00
|
|
|
#ifdef KTRACE
|
2002-06-07 05:42:25 +00:00
|
|
|
if (KTRPOINT(td, KTR_SYSRET))
|
|
|
|
ktrsysret(SYS_fork, 0, 0);
|
2001-01-24 10:47:14 +00:00
|
|
|
#endif
|
|
|
|
mtx_assert(&Giant, MA_NOTOWNED);
|
|
|
|
}
|