977 lines
24 KiB
C
977 lines
24 KiB
C
/* $NetBSD: kern_exit.c,v 1.242 2012/09/27 20:43:15 rmind Exp $ */
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/*-
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* Copyright (c) 1998, 1999, 2006, 2007, 2008 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
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* NASA Ames Research Center, and by Andrew Doran.
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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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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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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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* 3. 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_exit.c 8.10 (Berkeley) 2/23/95
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: kern_exit.c,v 1.242 2012/09/27 20:43:15 rmind Exp $");
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#include "opt_ktrace.h"
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#include "opt_perfctrs.h"
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#include "opt_sysv.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/ioctl.h>
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#include <sys/tty.h>
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#include <sys/time.h>
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#include <sys/resource.h>
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#include <sys/kernel.h>
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#include <sys/proc.h>
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#include <sys/buf.h>
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#include <sys/wait.h>
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#include <sys/file.h>
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#include <sys/vnode.h>
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#include <sys/syslog.h>
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#include <sys/pool.h>
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#include <sys/uidinfo.h>
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#if defined(PERFCTRS)
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#include <sys/pmc.h>
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#endif
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#include <sys/ptrace.h>
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#include <sys/acct.h>
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#include <sys/filedesc.h>
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#include <sys/ras.h>
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#include <sys/signalvar.h>
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#include <sys/sched.h>
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#include <sys/mount.h>
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#include <sys/syscallargs.h>
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#include <sys/kauth.h>
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#include <sys/sleepq.h>
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#include <sys/lockdebug.h>
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#include <sys/ktrace.h>
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#include <sys/cpu.h>
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#include <sys/lwpctl.h>
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#include <sys/atomic.h>
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#include <sys/sdt.h>
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#include <uvm/uvm_extern.h>
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#ifdef DEBUG_EXIT
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int debug_exit = 0;
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#define DPRINTF(x) if (debug_exit) printf x
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#else
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#define DPRINTF(x)
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#endif
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static int find_stopped_child(struct proc *, pid_t, int, struct proc **, int *);
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static void proc_free(struct proc *, struct rusage *);
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/*
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* DTrace SDT provider definitions
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*/
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SDT_PROBE_DEFINE(proc,,,exit,
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"int", NULL, /* reason */
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NULL, NULL, NULL, NULL,
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NULL, NULL, NULL, NULL);
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/*
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* Fill in the appropriate signal information, and signal the parent.
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*/
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/* XXX noclone works around a gcc 4.5 bug on arm */
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static void __noclone
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exit_psignal(struct proc *p, struct proc *pp, ksiginfo_t *ksi)
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{
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KSI_INIT(ksi);
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if ((ksi->ksi_signo = P_EXITSIG(p)) == SIGCHLD) {
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if (WIFSIGNALED(p->p_xstat)) {
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if (WCOREDUMP(p->p_xstat))
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ksi->ksi_code = CLD_DUMPED;
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else
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ksi->ksi_code = CLD_KILLED;
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} else {
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ksi->ksi_code = CLD_EXITED;
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}
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}
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/*
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* We fill those in, even for non-SIGCHLD.
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* It's safe to access p->p_cred unlocked here.
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*/
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ksi->ksi_pid = p->p_pid;
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ksi->ksi_uid = kauth_cred_geteuid(p->p_cred);
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ksi->ksi_status = p->p_xstat;
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/* XXX: is this still valid? */
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ksi->ksi_utime = p->p_stats->p_ru.ru_utime.tv_sec;
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ksi->ksi_stime = p->p_stats->p_ru.ru_stime.tv_sec;
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}
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/*
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* exit --
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* Death of process.
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*/
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int
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sys_exit(struct lwp *l, const struct sys_exit_args *uap, register_t *retval)
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{
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/* {
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syscallarg(int) rval;
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} */
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struct proc *p = l->l_proc;
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/* Don't call exit1() multiple times in the same process. */
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mutex_enter(p->p_lock);
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if (p->p_sflag & PS_WEXIT) {
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mutex_exit(p->p_lock);
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lwp_exit(l);
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}
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/* exit1() will release the mutex. */
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exit1(l, W_EXITCODE(SCARG(uap, rval), 0));
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/* NOTREACHED */
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return (0);
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}
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/*
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* Exit: deallocate address space and other resources, change proc state
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* to zombie, and unlink proc from allproc and parent's lists. Save exit
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* status and rusage for wait(). Check for child processes and orphan them.
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*
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* Must be called with p->p_lock held. Does not return.
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*/
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void
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exit1(struct lwp *l, int rv)
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{
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struct proc *p, *child, *next_child, *old_parent, *new_parent;
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struct pgrp *pgrp;
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ksiginfo_t ksi;
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ksiginfoq_t kq;
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int wakeinit;
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p = l->l_proc;
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KASSERT(mutex_owned(p->p_lock));
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KASSERT(p->p_vmspace != NULL);
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if (__predict_false(p == initproc)) {
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panic("init died (signal %d, exit %d)",
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WTERMSIG(rv), WEXITSTATUS(rv));
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}
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p->p_sflag |= PS_WEXIT;
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/*
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* Force all other LWPs to exit before we do. Only then can we
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* begin to tear down the rest of the process state.
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*/
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if (p->p_nlwps > 1) {
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exit_lwps(l);
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}
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ksiginfo_queue_init(&kq);
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/*
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* If we have been asked to stop on exit, do so now.
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*/
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if (__predict_false(p->p_sflag & PS_STOPEXIT)) {
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KERNEL_UNLOCK_ALL(l, &l->l_biglocks);
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sigclearall(p, &contsigmask, &kq);
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p->p_waited = 0;
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membar_producer();
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p->p_stat = SSTOP;
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lwp_lock(l);
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p->p_nrlwps--;
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l->l_stat = LSSTOP;
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lwp_unlock(l);
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mutex_exit(p->p_lock);
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lwp_lock(l);
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mi_switch(l);
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KERNEL_LOCK(l->l_biglocks, l);
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mutex_enter(p->p_lock);
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}
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/*
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* Bin any remaining signals and mark the process as dying so it will
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* not be found for, e.g. signals.
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*/
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sigfillset(&p->p_sigctx.ps_sigignore);
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sigclearall(p, NULL, &kq);
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p->p_stat = SDYING;
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mutex_exit(p->p_lock);
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ksiginfo_queue_drain(&kq);
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/* Destroy any lwpctl info. */
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if (p->p_lwpctl != NULL)
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lwp_ctl_exit();
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/*
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* Drain all remaining references that procfs, ptrace and others may
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* have on the process.
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*/
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rw_enter(&p->p_reflock, RW_WRITER);
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DPRINTF(("exit1: %d.%d exiting.\n", p->p_pid, l->l_lid));
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timers_free(p, TIMERS_ALL);
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#if defined(__HAVE_RAS)
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ras_purgeall();
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#endif
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/*
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* Close open files, release open-file table and free signal
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* actions. This may block!
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*/
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fd_free();
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cwdfree(p->p_cwdi);
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p->p_cwdi = NULL;
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doexithooks(p);
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sigactsfree(p->p_sigacts);
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/*
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* Write out accounting data.
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*/
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(void)acct_process(l);
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#ifdef KTRACE
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/*
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* Release trace file.
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*/
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if (p->p_tracep != NULL) {
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mutex_enter(&ktrace_lock);
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ktrderef(p);
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mutex_exit(&ktrace_lock);
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}
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#endif
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/*
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* If emulation has process exit hook, call it now.
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* Set the exit status now so that the exit hook has
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* an opportunity to tweak it (COMPAT_LINUX requires
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* this for thread group emulation)
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*/
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p->p_xstat = rv;
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if (p->p_emul->e_proc_exit)
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(*p->p_emul->e_proc_exit)(p);
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/*
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* Free the VM resources we're still holding on to.
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* We must do this from a valid thread because doing
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* so may block. This frees vmspace, which we don't
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* need anymore. The only remaining lwp is the one
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* we run at this moment, nothing runs in userland
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* anymore.
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*/
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uvm_proc_exit(p);
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/*
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* Stop profiling.
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*/
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if (__predict_false((p->p_stflag & PST_PROFIL) != 0)) {
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mutex_spin_enter(&p->p_stmutex);
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stopprofclock(p);
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mutex_spin_exit(&p->p_stmutex);
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}
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/*
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* If parent is waiting for us to exit or exec, PL_PPWAIT is set; we
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* wake up the parent early to avoid deadlock. We can do this once
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* the VM resources are released.
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*/
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mutex_enter(proc_lock);
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if (p->p_lflag & PL_PPWAIT) {
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#if 0
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lwp_t *lp;
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l->l_lwpctl = NULL; /* was on loan from blocked parent */
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p->p_lflag &= ~PL_PPWAIT;
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lp = p->p_vforklwp;
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p->p_vforklwp = NULL;
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lp->l_pflag &= ~LP_VFORKWAIT; /* XXX */
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cv_broadcast(&lp->l_waitcv);
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#else
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l->l_lwpctl = NULL; /* was on loan from blocked parent */
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p->p_lflag &= ~PL_PPWAIT;
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cv_broadcast(&p->p_pptr->p_waitcv);
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#endif
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}
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if (SESS_LEADER(p)) {
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struct vnode *vprele = NULL, *vprevoke = NULL;
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struct session *sp = p->p_session;
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struct tty *tp;
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if (sp->s_ttyvp) {
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/*
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* Controlling process.
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* Signal foreground pgrp,
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* drain controlling terminal
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* and revoke access to controlling terminal.
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*/
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tp = sp->s_ttyp;
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mutex_spin_enter(&tty_lock);
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if (tp->t_session == sp) {
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/* we can't guarantee the revoke will do this */
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pgrp = tp->t_pgrp;
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tp->t_pgrp = NULL;
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tp->t_session = NULL;
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mutex_spin_exit(&tty_lock);
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if (pgrp != NULL) {
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pgsignal(pgrp, SIGHUP, 1);
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}
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mutex_exit(proc_lock);
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(void) ttywait(tp);
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mutex_enter(proc_lock);
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/* The tty could have been revoked. */
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vprevoke = sp->s_ttyvp;
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} else
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mutex_spin_exit(&tty_lock);
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vprele = sp->s_ttyvp;
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sp->s_ttyvp = NULL;
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/*
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* s_ttyp is not zero'd; we use this to indicate
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* that the session once had a controlling terminal.
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* (for logging and informational purposes)
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*/
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}
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sp->s_leader = NULL;
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if (vprevoke != NULL || vprele != NULL) {
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if (vprevoke != NULL) {
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/* Releases proc_lock. */
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proc_sessrele(sp);
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VOP_REVOKE(vprevoke, REVOKEALL);
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} else
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mutex_exit(proc_lock);
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if (vprele != NULL)
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vrele(vprele);
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mutex_enter(proc_lock);
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}
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}
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fixjobc(p, p->p_pgrp, 0);
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/*
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* Finalize the last LWP's specificdata, as well as the
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* specificdata for the proc itself.
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*/
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lwp_finispecific(l);
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proc_finispecific(p);
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/*
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* Notify interested parties of our demise.
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*/
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KNOTE(&p->p_klist, NOTE_EXIT);
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SDT_PROBE(proc,,,exit,
|
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(WCOREDUMP(rv) ? CLD_DUMPED :
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(WIFSIGNALED(rv) ? CLD_KILLED : CLD_EXITED)),
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0,0,0,0);
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#if PERFCTRS
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/*
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* Save final PMC information in parent process & clean up.
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*/
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if (PMC_ENABLED(p)) {
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pmc_save_context(p);
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pmc_accumulate(p->p_pptr, p);
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pmc_process_exit(p);
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}
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#endif
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/*
|
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* Reset p_opptr pointer of all former children which got
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* traced by another process and were reparented. We reset
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* it to NULL here; the trace detach code then reparents
|
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* the child to initproc. We only check allproc list, since
|
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* eventual former children on zombproc list won't reference
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* p_opptr anymore.
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*/
|
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if (__predict_false(p->p_slflag & PSL_CHTRACED)) {
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struct proc *q;
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PROCLIST_FOREACH(q, &allproc) {
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if (q->p_opptr == p)
|
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q->p_opptr = NULL;
|
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}
|
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}
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|
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/*
|
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* Give orphaned children to init(8).
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*/
|
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child = LIST_FIRST(&p->p_children);
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wakeinit = (child != NULL);
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for (; child != NULL; child = next_child) {
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next_child = LIST_NEXT(child, p_sibling);
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|
|
/*
|
|
* Traced processes are killed since their existence
|
|
* means someone is screwing up. Since we reset the
|
|
* trace flags, the logic in sys_wait4() would not be
|
|
* triggered to reparent the process to its
|
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* original parent, so we must do this here.
|
|
*/
|
|
if (__predict_false(child->p_slflag & PSL_TRACED)) {
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mutex_enter(p->p_lock);
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|
child->p_slflag &=
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~(PSL_TRACED|PSL_FSTRACE|PSL_SYSCALL);
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mutex_exit(p->p_lock);
|
|
if (child->p_opptr != child->p_pptr) {
|
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struct proc *t = child->p_opptr;
|
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proc_reparent(child, t ? t : initproc);
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child->p_opptr = NULL;
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} else
|
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proc_reparent(child, initproc);
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killproc(child, "orphaned traced process");
|
|
} else
|
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proc_reparent(child, initproc);
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}
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|
|
/*
|
|
* Move proc from allproc to zombproc, it's now nearly ready to be
|
|
* collected by parent.
|
|
*/
|
|
LIST_REMOVE(l, l_list);
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LIST_REMOVE(p, p_list);
|
|
LIST_INSERT_HEAD(&zombproc, p, p_list);
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|
|
/*
|
|
* Mark the process as dead. We must do this before we signal
|
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* the parent.
|
|
*/
|
|
p->p_stat = SDEAD;
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|
|
/* Put in front of parent's sibling list for parent to collect it */
|
|
old_parent = p->p_pptr;
|
|
old_parent->p_nstopchild++;
|
|
if (LIST_FIRST(&old_parent->p_children) != p) {
|
|
/* Put child where it can be found quickly */
|
|
LIST_REMOVE(p, p_sibling);
|
|
LIST_INSERT_HEAD(&old_parent->p_children, p, p_sibling);
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|
}
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|
|
/*
|
|
* Notify parent that we're gone. If parent has the P_NOCLDWAIT
|
|
* flag set, notify init instead (and hope it will handle
|
|
* this situation).
|
|
*/
|
|
if (old_parent->p_flag & (PK_NOCLDWAIT|PK_CLDSIGIGN)) {
|
|
proc_reparent(p, initproc);
|
|
wakeinit = 1;
|
|
|
|
/*
|
|
* If this was the last child of our parent, notify
|
|
* parent, so in case he was wait(2)ing, he will
|
|
* continue.
|
|
*/
|
|
if (LIST_FIRST(&old_parent->p_children) == NULL)
|
|
cv_broadcast(&old_parent->p_waitcv);
|
|
}
|
|
|
|
/* Reload parent pointer, since p may have been reparented above */
|
|
new_parent = p->p_pptr;
|
|
|
|
if (__predict_false((p->p_slflag & PSL_FSTRACE) == 0 &&
|
|
p->p_exitsig != 0)) {
|
|
exit_psignal(p, new_parent, &ksi);
|
|
kpsignal(new_parent, &ksi, NULL);
|
|
}
|
|
|
|
/* Calculate the final rusage info. */
|
|
calcru(p, &p->p_stats->p_ru.ru_utime, &p->p_stats->p_ru.ru_stime,
|
|
NULL, NULL);
|
|
|
|
if (wakeinit)
|
|
cv_broadcast(&initproc->p_waitcv);
|
|
|
|
callout_destroy(&l->l_timeout_ch);
|
|
|
|
/*
|
|
* Release any PCU resources before becoming a zombie.
|
|
*/
|
|
pcu_discard_all(l);
|
|
|
|
/*
|
|
* Remaining lwp resources will be freed in lwp_exit2() once we've
|
|
* switch to idle context; at that point, we will be marked as a
|
|
* full blown zombie.
|
|
*/
|
|
mutex_enter(p->p_lock);
|
|
lwp_drainrefs(l);
|
|
lwp_lock(l);
|
|
l->l_prflag &= ~LPR_DETACHED;
|
|
l->l_stat = LSZOMB;
|
|
lwp_unlock(l);
|
|
KASSERT(curlwp == l);
|
|
KASSERT(p->p_nrlwps == 1);
|
|
KASSERT(p->p_nlwps == 1);
|
|
p->p_stat = SZOMB;
|
|
p->p_nrlwps--;
|
|
p->p_nzlwps++;
|
|
p->p_ndlwps = 0;
|
|
mutex_exit(p->p_lock);
|
|
|
|
/*
|
|
* Signal the parent to collect us, and drop the proclist lock.
|
|
* Drop debugger/procfs lock; no new references can be gained.
|
|
*/
|
|
cv_broadcast(&p->p_pptr->p_waitcv);
|
|
rw_exit(&p->p_reflock);
|
|
mutex_exit(proc_lock);
|
|
|
|
/* Verify that we hold no locks other than the kernel lock. */
|
|
LOCKDEBUG_BARRIER(&kernel_lock, 0);
|
|
|
|
/*
|
|
* NOTE: WE ARE NO LONGER ALLOWED TO SLEEP!
|
|
*/
|
|
|
|
/*
|
|
* Give machine-dependent code a chance to free any MD LWP
|
|
* resources. This must be done before uvm_lwp_exit(), in
|
|
* case these resources are in the PCB.
|
|
*/
|
|
cpu_lwp_free(l, 1);
|
|
|
|
pmap_deactivate(l);
|
|
|
|
/* This process no longer needs to hold the kernel lock. */
|
|
#ifdef notyet
|
|
/* XXXSMP hold in lwp_userret() */
|
|
KERNEL_UNLOCK_LAST(l);
|
|
#else
|
|
KERNEL_UNLOCK_ALL(l, NULL);
|
|
#endif
|
|
|
|
lwp_exit_switchaway(l);
|
|
}
|
|
|
|
void
|
|
exit_lwps(struct lwp *l)
|
|
{
|
|
proc_t *p = l->l_proc;
|
|
lwp_t *l2;
|
|
int nlocks;
|
|
|
|
KERNEL_UNLOCK_ALL(l, &nlocks);
|
|
retry:
|
|
KASSERT(mutex_owned(p->p_lock));
|
|
|
|
/*
|
|
* Interrupt LWPs in interruptable sleep, unsuspend suspended
|
|
* LWPs and then wait for everyone else to finish.
|
|
*/
|
|
LIST_FOREACH(l2, &p->p_lwps, l_sibling) {
|
|
if (l2 == l)
|
|
continue;
|
|
lwp_lock(l2);
|
|
l2->l_flag |= LW_WEXIT;
|
|
if ((l2->l_stat == LSSLEEP && (l2->l_flag & LW_SINTR)) ||
|
|
l2->l_stat == LSSUSPENDED || l2->l_stat == LSSTOP) {
|
|
/* setrunnable() will release the lock. */
|
|
setrunnable(l2);
|
|
continue;
|
|
}
|
|
lwp_unlock(l2);
|
|
}
|
|
|
|
/*
|
|
* Wait for every LWP to exit. Note: LWPs can get suspended/slept
|
|
* behind us or there may even be new LWPs created. Therefore, a
|
|
* full retry is required on error.
|
|
*/
|
|
while (p->p_nlwps > 1) {
|
|
if (lwp_wait(l, 0, NULL, true)) {
|
|
goto retry;
|
|
}
|
|
}
|
|
|
|
KERNEL_LOCK(nlocks, l);
|
|
KASSERT(p->p_nlwps == 1);
|
|
}
|
|
|
|
int
|
|
do_sys_wait(int *pid, int *status, int options, struct rusage *ru)
|
|
{
|
|
proc_t *child;
|
|
int error;
|
|
|
|
if (ru != NULL) {
|
|
memset(ru, 0, sizeof(*ru));
|
|
}
|
|
mutex_enter(proc_lock);
|
|
error = find_stopped_child(curproc, *pid, options, &child, status);
|
|
if (child == NULL) {
|
|
mutex_exit(proc_lock);
|
|
*pid = 0;
|
|
return error;
|
|
}
|
|
*pid = child->p_pid;
|
|
|
|
if (child->p_stat == SZOMB) {
|
|
/* proc_free() will release the proc_lock. */
|
|
if (options & WNOWAIT) {
|
|
mutex_exit(proc_lock);
|
|
} else {
|
|
proc_free(child, ru);
|
|
}
|
|
} else {
|
|
/* Child state must have been SSTOP. */
|
|
mutex_exit(proc_lock);
|
|
*status = W_STOPCODE(*status);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
sys___wait450(struct lwp *l, const struct sys___wait450_args *uap,
|
|
register_t *retval)
|
|
{
|
|
/* {
|
|
syscallarg(int) pid;
|
|
syscallarg(int *) status;
|
|
syscallarg(int) options;
|
|
syscallarg(struct rusage *) rusage;
|
|
} */
|
|
int error, status, pid = SCARG(uap, pid);
|
|
struct rusage ru;
|
|
|
|
error = do_sys_wait(&pid, &status, SCARG(uap, options),
|
|
SCARG(uap, rusage) != NULL ? &ru : NULL);
|
|
|
|
retval[0] = pid;
|
|
if (pid == 0) {
|
|
return error;
|
|
}
|
|
if (SCARG(uap, status)) {
|
|
error = copyout(&status, SCARG(uap, status), sizeof(status));
|
|
}
|
|
if (SCARG(uap, rusage) && error == 0) {
|
|
error = copyout(&ru, SCARG(uap, rusage), sizeof(ru));
|
|
}
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Scan list of child processes for a child process that has stopped or
|
|
* exited. Used by sys_wait4 and 'compat' equivalents.
|
|
*
|
|
* Must be called with the proc_lock held, and may release while waiting.
|
|
*/
|
|
static int
|
|
find_stopped_child(struct proc *parent, pid_t pid, int options,
|
|
struct proc **child_p, int *status_p)
|
|
{
|
|
struct proc *child, *dead;
|
|
int error;
|
|
|
|
KASSERT(mutex_owned(proc_lock));
|
|
|
|
if (options & ~(WUNTRACED|WNOHANG|WALTSIG|WALLSIG)
|
|
&& !(options & WOPTSCHECKED)) {
|
|
*child_p = NULL;
|
|
return EINVAL;
|
|
}
|
|
|
|
if (pid == 0 && !(options & WOPTSCHECKED))
|
|
pid = -parent->p_pgid;
|
|
|
|
for (;;) {
|
|
error = ECHILD;
|
|
dead = NULL;
|
|
|
|
LIST_FOREACH(child, &parent->p_children, p_sibling) {
|
|
if (pid >= 0) {
|
|
if (child->p_pid != pid) {
|
|
child = proc_find_raw(pid);
|
|
if (child == NULL ||
|
|
child->p_stat == SIDL ||
|
|
child->p_pptr != parent) {
|
|
child = NULL;
|
|
break;
|
|
}
|
|
}
|
|
} else if (pid != WAIT_ANY && child->p_pgid != -pid) {
|
|
/* Child not in correct pgrp */
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Wait for processes with p_exitsig != SIGCHLD
|
|
* processes only if WALTSIG is set; wait for
|
|
* processes with p_exitsig == SIGCHLD only
|
|
* if WALTSIG is clear.
|
|
*/
|
|
if (((options & WALLSIG) == 0) &&
|
|
(options & WALTSIG ? child->p_exitsig == SIGCHLD
|
|
: P_EXITSIG(child) != SIGCHLD)){
|
|
if (child->p_pid == pid) {
|
|
child = NULL;
|
|
break;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
error = 0;
|
|
if ((options & WNOZOMBIE) == 0) {
|
|
if (child->p_stat == SZOMB)
|
|
break;
|
|
if (child->p_stat == SDEAD) {
|
|
/*
|
|
* We may occasionally arrive here
|
|
* after receiving a signal, but
|
|
* immediately before the child
|
|
* process is zombified. The wait
|
|
* will be short, so avoid returning
|
|
* to userspace.
|
|
*/
|
|
dead = child;
|
|
}
|
|
}
|
|
|
|
if (child->p_stat == SSTOP &&
|
|
child->p_waited == 0 &&
|
|
(child->p_slflag & PSL_TRACED ||
|
|
options & WUNTRACED)) {
|
|
if ((options & WNOWAIT) == 0) {
|
|
child->p_waited = 1;
|
|
parent->p_nstopchild--;
|
|
}
|
|
break;
|
|
}
|
|
if (parent->p_nstopchild == 0 || child->p_pid == pid) {
|
|
child = NULL;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (child != NULL || error != 0 ||
|
|
((options & WNOHANG) != 0 && dead == NULL)) {
|
|
if (child != NULL) {
|
|
*status_p = child->p_xstat;
|
|
}
|
|
*child_p = child;
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Wait for another child process to stop.
|
|
*/
|
|
error = cv_wait_sig(&parent->p_waitcv, proc_lock);
|
|
|
|
if (error != 0) {
|
|
*child_p = NULL;
|
|
return error;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Free a process after parent has taken all the state info. Must be called
|
|
* with the proclist lock held, and will release before returning.
|
|
*
|
|
* *ru is returned to the caller, and must be freed by the caller.
|
|
*/
|
|
static void
|
|
proc_free(struct proc *p, struct rusage *ru)
|
|
{
|
|
struct proc *parent = p->p_pptr;
|
|
struct lwp *l;
|
|
ksiginfo_t ksi;
|
|
kauth_cred_t cred1, cred2;
|
|
uid_t uid;
|
|
|
|
KASSERT(mutex_owned(proc_lock));
|
|
KASSERT(p->p_nlwps == 1);
|
|
KASSERT(p->p_nzlwps == 1);
|
|
KASSERT(p->p_nrlwps == 0);
|
|
KASSERT(p->p_stat == SZOMB);
|
|
|
|
/*
|
|
* If we got the child via ptrace(2) or procfs, and
|
|
* the parent is different (meaning the process was
|
|
* attached, rather than run as a child), then we need
|
|
* to give it back to the old parent, and send the
|
|
* parent the exit signal. The rest of the cleanup
|
|
* will be done when the old parent waits on the child.
|
|
*/
|
|
if ((p->p_slflag & PSL_TRACED) != 0 && p->p_opptr != parent) {
|
|
mutex_enter(p->p_lock);
|
|
p->p_slflag &= ~(PSL_TRACED|PSL_FSTRACE|PSL_SYSCALL);
|
|
mutex_exit(p->p_lock);
|
|
parent = (p->p_opptr == NULL) ? initproc : p->p_opptr;
|
|
proc_reparent(p, parent);
|
|
p->p_opptr = NULL;
|
|
if (p->p_exitsig != 0) {
|
|
exit_psignal(p, parent, &ksi);
|
|
kpsignal(parent, &ksi, NULL);
|
|
}
|
|
cv_broadcast(&parent->p_waitcv);
|
|
mutex_exit(proc_lock);
|
|
return;
|
|
}
|
|
|
|
sched_proc_exit(parent, p);
|
|
|
|
/*
|
|
* Add child times of exiting process onto its own times.
|
|
* This cannot be done any earlier else it might get done twice.
|
|
*/
|
|
l = LIST_FIRST(&p->p_lwps);
|
|
p->p_stats->p_ru.ru_nvcsw += (l->l_ncsw - l->l_nivcsw);
|
|
p->p_stats->p_ru.ru_nivcsw += l->l_nivcsw;
|
|
ruadd(&p->p_stats->p_ru, &l->l_ru);
|
|
ruadd(&p->p_stats->p_ru, &p->p_stats->p_cru);
|
|
ruadd(&parent->p_stats->p_cru, &p->p_stats->p_ru);
|
|
if (ru != NULL)
|
|
*ru = p->p_stats->p_ru;
|
|
p->p_xstat = 0;
|
|
|
|
/*
|
|
* At this point we are going to start freeing the final resources.
|
|
* If anyone tries to access the proc structure after here they will
|
|
* get a shock - bits are missing. Attempt to make it hard! We
|
|
* don't bother with any further locking past this point.
|
|
*/
|
|
p->p_stat = SIDL; /* not even a zombie any more */
|
|
LIST_REMOVE(p, p_list); /* off zombproc */
|
|
parent->p_nstopchild--;
|
|
LIST_REMOVE(p, p_sibling);
|
|
|
|
/*
|
|
* Let pid be reallocated.
|
|
*/
|
|
proc_free_pid(p->p_pid);
|
|
|
|
/*
|
|
* Unlink process from its process group.
|
|
* Releases the proc_lock.
|
|
*/
|
|
proc_leavepgrp(p);
|
|
|
|
/*
|
|
* Delay release until after lwp_free.
|
|
*/
|
|
cred2 = l->l_cred;
|
|
|
|
/*
|
|
* Free the last LWP's resources.
|
|
*
|
|
* lwp_free ensures the LWP is no longer running on another CPU.
|
|
*/
|
|
lwp_free(l, false, true);
|
|
|
|
/*
|
|
* Now no one except us can reach the process p.
|
|
*/
|
|
|
|
/*
|
|
* Decrement the count of procs running with this uid.
|
|
*/
|
|
cred1 = p->p_cred;
|
|
uid = kauth_cred_getuid(cred1);
|
|
(void)chgproccnt(uid, -1);
|
|
|
|
/*
|
|
* Release substructures.
|
|
*/
|
|
|
|
lim_free(p->p_limit);
|
|
pstatsfree(p->p_stats);
|
|
kauth_cred_free(cred1);
|
|
kauth_cred_free(cred2);
|
|
|
|
/*
|
|
* Release reference to text vnode
|
|
*/
|
|
if (p->p_textvp)
|
|
vrele(p->p_textvp);
|
|
|
|
mutex_destroy(&p->p_auxlock);
|
|
mutex_obj_free(p->p_lock);
|
|
mutex_destroy(&p->p_stmutex);
|
|
cv_destroy(&p->p_waitcv);
|
|
cv_destroy(&p->p_lwpcv);
|
|
rw_destroy(&p->p_reflock);
|
|
|
|
proc_free_mem(p);
|
|
}
|
|
|
|
/*
|
|
* make process 'parent' the new parent of process 'child'.
|
|
*
|
|
* Must be called with proc_lock held.
|
|
*/
|
|
void
|
|
proc_reparent(struct proc *child, struct proc *parent)
|
|
{
|
|
|
|
KASSERT(mutex_owned(proc_lock));
|
|
|
|
if (child->p_pptr == parent)
|
|
return;
|
|
|
|
if (child->p_stat == SZOMB ||
|
|
(child->p_stat == SSTOP && !child->p_waited)) {
|
|
child->p_pptr->p_nstopchild--;
|
|
parent->p_nstopchild++;
|
|
}
|
|
if (parent == initproc)
|
|
child->p_exitsig = SIGCHLD;
|
|
|
|
LIST_REMOVE(child, p_sibling);
|
|
LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
|
|
child->p_pptr = parent;
|
|
child->p_ppid = parent->p_pid;
|
|
}
|