initial import of NetBSD tree

1 files changed, 1137 insertions, 0 deletions

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
new file mode 100644
index 00000000000..804b559aba2
--- /dev/null
+++ b/sys/kern/kern_sig.c
@@ -0,0 +1,1137 @@
+/*	$NetBSD: kern_sig.c,v 1.50 1995/10/07 06:28:25 mycroft Exp $	*/
+
+/*
+ * Copyright (c) 1982, 1986, 1989, 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * (c) UNIX System Laboratories, Inc.
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)kern_sig.c	8.7 (Berkeley) 4/18/94
+ */
+
+#define	SIGPROP		/* include signal properties table */
+#include <sys/param.h>
+#include <sys/signalvar.h>
+#include <sys/resourcevar.h>
+#include <sys/namei.h>
+#include <sys/vnode.h>
+#include <sys/proc.h>
+#include <sys/systm.h>
+#include <sys/timeb.h>
+#include <sys/times.h>
+#include <sys/buf.h>
+#include <sys/acct.h>
+#include <sys/file.h>
+#include <sys/kernel.h>
+#include <sys/wait.h>
+#include <sys/ktrace.h>
+#include <sys/syslog.h>
+#include <sys/stat.h>
+#include <sys/core.h>
+
+#include <sys/mount.h>
+#include <sys/syscallargs.h>
+
+#include <machine/cpu.h>
+
+#include <vm/vm.h>
+#include <sys/user.h>		/* for coredump */
+
+void stop __P((struct proc *p));
+
+/*
+ * Can process p, with pcred pc, send the signal signum to process q?
+ */
+#define CANSIGNAL(p, pc, q, signum) \
+	((pc)->pc_ucred->cr_uid == 0 || \
+	    (pc)->p_ruid == (q)->p_cred->p_ruid || \
+	    (pc)->pc_ucred->cr_uid == (q)->p_cred->p_ruid || \
+	    (pc)->p_ruid == (q)->p_ucred->cr_uid || \
+	    (pc)->pc_ucred->cr_uid == (q)->p_ucred->cr_uid || \
+	    ((signum) == SIGCONT && (q)->p_session == (p)->p_session))
+
+/* ARGSUSED */
+sys_sigaction(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	register struct sys_sigaction_args /* {
+		syscallarg(int) signum;
+		syscallarg(struct sigaction *) nsa;
+		syscallarg(struct sigaction *) osa;
+	} */ *uap = v;
+	struct sigaction vec;
+	register struct sigaction *sa;
+	register struct sigacts *ps = p->p_sigacts;
+	register int signum;
+	int bit, error;
+
+	signum = SCARG(uap, signum);
+	if (signum <= 0 || signum >= NSIG ||
+	    signum == SIGKILL || signum == SIGSTOP)
+		return (EINVAL);
+	sa = &vec;
+	if (SCARG(uap, osa)) {
+		sa->sa_handler = ps->ps_sigact[signum];
+		sa->sa_mask = ps->ps_catchmask[signum];
+		bit = sigmask(signum);
+		sa->sa_flags = 0;
+		if ((ps->ps_sigonstack & bit) != 0)
+			sa->sa_flags |= SA_ONSTACK;
+		if ((ps->ps_sigintr & bit) == 0)
+			sa->sa_flags |= SA_RESTART;
+		if ((ps->ps_sigreset & bit) != 0)
+			sa->sa_flags |= SA_RESETHAND;
+		if (signum == SIGCHLD) {
+			if ((p->p_flag & P_NOCLDSTOP) != 0)
+				sa->sa_flags |= SA_NOCLDSTOP;
+		}
+		if ((sa->sa_mask & bit) == 0)
+			sa->sa_flags |= SA_NODEFER;
+		sa->sa_mask &= ~bit;
+		if (error = copyout((caddr_t)sa, (caddr_t)SCARG(uap, osa),
+		    sizeof (vec)))
+			return (error);
+	}
+	if (SCARG(uap, nsa)) {
+		if (error = copyin((caddr_t)SCARG(uap, nsa), (caddr_t)sa,
+		    sizeof (vec)))
+			return (error);
+		setsigvec(p, signum, sa);
+	}
+	return (0);
+}
+
+setsigvec(p, signum, sa)
+	register struct proc *p;
+	int signum;
+	register struct sigaction *sa;
+{
+	register struct sigacts *ps = p->p_sigacts;
+	register int bit;
+
+	bit = sigmask(signum);
+	/*
+	 * Change setting atomically.
+	 */
+	(void) splhigh();
+	ps->ps_sigact[signum] = sa->sa_handler;
+	if ((sa->sa_flags & SA_NODEFER) == 0)
+		sa->sa_mask |= sigmask(signum);
+	ps->ps_catchmask[signum] = sa->sa_mask &~ sigcantmask;
+	if (signum == SIGCHLD) {
+		if (sa->sa_flags & SA_NOCLDSTOP)
+			p->p_flag |= P_NOCLDSTOP;
+		else
+			p->p_flag &= ~P_NOCLDSTOP;
+	}
+	if ((sa->sa_flags & SA_RESETHAND) != 0)
+		ps->ps_sigreset |= bit;
+	else
+		ps->ps_sigreset &= ~bit;
+	if ((sa->sa_flags & SA_RESTART) == 0)
+		ps->ps_sigintr |= bit;
+	else
+		ps->ps_sigintr &= ~bit;
+	if ((sa->sa_flags & SA_ONSTACK) != 0)
+		ps->ps_sigonstack |= bit;
+	else
+		ps->ps_sigonstack &= ~bit;
+#ifdef COMPAT_SUNOS
+	{
+		extern struct emul emul_sunos;
+		if (p->p_emul == &emul_sunos && sa->sa_flags & SA_USERTRAMP)
+			ps->ps_usertramp |= bit;
+		else
+			ps->ps_usertramp &= ~bit;
+	}
+#endif
+	/*
+	 * Set bit in p_sigignore for signals that are set to SIG_IGN,
+	 * and for signals set to SIG_DFL where the default is to ignore.
+	 * However, don't put SIGCONT in p_sigignore,
+	 * as we have to restart the process.
+	 */
+	if (sa->sa_handler == SIG_IGN ||
+	    (sigprop[signum] & SA_IGNORE && sa->sa_handler == SIG_DFL)) {
+		p->p_siglist &= ~bit;		/* never to be seen again */
+		if (signum != SIGCONT)
+			p->p_sigignore |= bit;	/* easier in psignal */
+		p->p_sigcatch &= ~bit;
+	} else {
+		p->p_sigignore &= ~bit;
+		if (sa->sa_handler == SIG_DFL)
+			p->p_sigcatch &= ~bit;
+		else
+			p->p_sigcatch |= bit;
+	}
+	(void) spl0();
+}
+
+/*
+ * Initialize signal state for process 0;
+ * set to ignore signals that are ignored by default.
+ */
+void
+siginit(p)
+	struct proc *p;
+{
+	register int i;
+
+	for (i = 0; i < NSIG; i++)
+		if (sigprop[i] & SA_IGNORE && i != SIGCONT)
+			p->p_sigignore |= sigmask(i);
+}
+
+/*
+ * Reset signals for an exec of the specified process.
+ */
+void
+execsigs(p)
+	register struct proc *p;
+{
+	register struct sigacts *ps = p->p_sigacts;
+	register int nc, mask;
+
+	/*
+	 * Reset caught signals.  Held signals remain held
+	 * through p_sigmask (unless they were caught,
+	 * and are now ignored by default).
+	 */
+	while (p->p_sigcatch) {
+		nc = ffs((long)p->p_sigcatch);
+		mask = sigmask(nc);
+		p->p_sigcatch &= ~mask;
+		if (sigprop[nc] & SA_IGNORE) {
+			if (nc != SIGCONT)
+				p->p_sigignore |= mask;
+			p->p_siglist &= ~mask;
+		}
+		ps->ps_sigact[nc] = SIG_DFL;
+	}
+	/*
+	 * Reset stack state to the user stack.
+	 * Clear set of signals caught on the signal stack.
+	 */
+	ps->ps_sigstk.ss_flags = SS_DISABLE;
+	ps->ps_sigstk.ss_size = 0;
+	ps->ps_sigstk.ss_base = 0;
+	ps->ps_flags = 0;
+}
+
+/*
+ * Manipulate signal mask.
+ * Note that we receive new mask, not pointer,
+ * and return old mask as return value;
+ * the library stub does the rest.
+ */
+sys_sigprocmask(p, v, retval)
+	register struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_sigprocmask_args /* {
+		syscallarg(int) how;
+		syscallarg(sigset_t) mask;
+	} */ *uap = v;
+	int error = 0;
+
+	*retval = p->p_sigmask;
+	(void) splhigh();
+
+	switch (SCARG(uap, how)) {
+	case SIG_BLOCK:
+		p->p_sigmask |= SCARG(uap, mask) &~ sigcantmask;
+		break;
+
+	case SIG_UNBLOCK:
+		p->p_sigmask &= ~SCARG(uap, mask);
+		break;
+
+	case SIG_SETMASK:
+		p->p_sigmask = SCARG(uap, mask) &~ sigcantmask;
+		break;
+	
+	default:
+		error = EINVAL;
+		break;
+	}
+	(void) spl0();
+	return (error);
+}
+
+/* ARGSUSED */
+sys_sigpending(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+
+	*retval = p->p_siglist;
+	return (0);
+}
+
+/*
+ * Suspend process until signal, providing mask to be set
+ * in the meantime.  Note nonstandard calling convention:
+ * libc stub passes mask, not pointer, to save a copyin.
+ */
+/* ARGSUSED */
+int
+sys_sigsuspend(p, v, retval)
+	register struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_sigsuspend_args /* {
+		syscallarg(int) mask;
+	} */ *uap = v;
+	register struct sigacts *ps = p->p_sigacts;
+
+	/*
+	 * When returning from sigpause, we want
+	 * the old mask to be restored after the
+	 * signal handler has finished.  Thus, we
+	 * save it here and mark the sigacts structure
+	 * to indicate this.
+	 */
+	ps->ps_oldmask = p->p_sigmask;
+	ps->ps_flags |= SAS_OLDMASK;
+	p->p_sigmask = SCARG(uap, mask) &~ sigcantmask;
+	while (tsleep((caddr_t) ps, PPAUSE|PCATCH, "pause", 0) == 0)
+		/* void */;
+	/* always return EINTR rather than ERESTART... */
+	return (EINTR);
+}
+
+/* ARGSUSED */
+sys_sigaltstack(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	register struct sys_sigaltstack_args /* {
+		syscallarg(struct sigaltstack *) nss;
+		syscallarg(struct sigaltstack *) oss;
+	} */ *uap = v;
+	struct sigacts *psp;
+	struct sigaltstack ss;
+	int error;
+
+	psp = p->p_sigacts;
+	if ((psp->ps_flags & SAS_ALTSTACK) == 0)
+		psp->ps_sigstk.ss_flags |= SS_DISABLE;
+	if (SCARG(uap, oss) && (error = copyout((caddr_t)&psp->ps_sigstk,
+	    (caddr_t)SCARG(uap, oss), sizeof (struct sigaltstack))))
+		return (error);
+	if (SCARG(uap, nss) == 0)
+		return (0);
+	if (error = copyin((caddr_t)SCARG(uap, nss), (caddr_t)&ss,
+	    sizeof (ss)))
+		return (error);
+	if (ss.ss_flags & SS_DISABLE) {
+		if (psp->ps_sigstk.ss_flags & SS_ONSTACK)
+			return (EINVAL);
+		psp->ps_flags &= ~SAS_ALTSTACK;
+		psp->ps_sigstk.ss_flags = ss.ss_flags;
+		return (0);
+	}
+	if (ss.ss_size < MINSIGSTKSZ)
+		return (ENOMEM);
+	psp->ps_flags |= SAS_ALTSTACK;
+	psp->ps_sigstk= ss;
+	return (0);
+}
+
+/* ARGSUSED */
+int
+sys_kill(cp, v, retval)
+	register struct proc *cp;
+	void *v;
+	register_t *retval;
+{
+	register struct sys_kill_args /* {
+		syscallarg(int) pid;
+		syscallarg(int) signum;
+	} */ *uap = v;
+	register struct proc *p;
+	register struct pcred *pc = cp->p_cred;
+
+#ifdef COMPAT_09
+	SCARG(uap, pid) = (short) SCARG(uap, pid);
+#endif
+
+	if ((u_int)SCARG(uap, signum) >= NSIG)
+		return (EINVAL);
+	if (SCARG(uap, pid) > 0) {
+		/* kill single process */
+		if ((p = pfind(SCARG(uap, pid))) == NULL)
+			return (ESRCH);
+		if (!CANSIGNAL(cp, pc, p, SCARG(uap, signum)))
+			return (EPERM);
+		if (SCARG(uap, signum))
+			psignal(p, SCARG(uap, signum));
+		return (0);
+	}
+	switch (SCARG(uap, pid)) {
+	case -1:		/* broadcast signal */
+		return (killpg1(cp, SCARG(uap, signum), 0, 1));
+	case 0:			/* signal own process group */
+		return (killpg1(cp, SCARG(uap, signum), 0, 0));
+	default:		/* negative explicit process group */
+		return (killpg1(cp, SCARG(uap, signum), -SCARG(uap, pid), 0));
+	}
+	/* NOTREACHED */
+}
+
+/*
+ * Common code for kill process group/broadcast kill.
+ * cp is calling process.
+ */
+killpg1(cp, signum, pgid, all)
+	register struct proc *cp;
+	int signum, pgid, all;
+{
+	register struct proc *p;
+	register struct pcred *pc = cp->p_cred;
+	struct pgrp *pgrp;
+	int nfound = 0;
+	
+	if (all)	
+		/* 
+		 * broadcast 
+		 */
+		for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
+			if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 
+			    p == cp || !CANSIGNAL(cp, pc, p, signum))
+				continue;
+			nfound++;
+			if (signum)
+				psignal(p, signum);
+		}
+	else {
+		if (pgid == 0)		
+			/* 
+			 * zero pgid means send to my process group.
+			 */
+			pgrp = cp->p_pgrp;
+		else {
+			pgrp = pgfind(pgid);
+			if (pgrp == NULL)
+				return (ESRCH);
+		}
+		for (p = pgrp->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) {
+			if (p->p_pid <= 1 || p->p_flag & P_SYSTEM ||
+			    p->p_stat == SZOMB ||
+			    !CANSIGNAL(cp, pc, p, signum))
+				continue;
+			nfound++;
+			if (signum)
+				psignal(p, signum);
+		}
+	}
+	return (nfound ? 0 : ESRCH);
+}
+
+/*
+ * Send a signal to a process group.
+ */
+void
+gsignal(pgid, signum)
+	int pgid, signum;
+{
+	struct pgrp *pgrp;
+
+	if (pgid && (pgrp = pgfind(pgid)))
+		pgsignal(pgrp, signum, 0);
+}
+
+/*
+ * Send a signal to a process group.  If checktty is 1,
+ * limit to members which have a controlling terminal.
+ */
+void
+pgsignal(pgrp, signum, checkctty)
+	struct pgrp *pgrp;
+	int signum, checkctty;
+{
+	register struct proc *p;
+
+	if (pgrp)
+		for (p = pgrp->pg_members.lh_first; p != 0; p = p->p_pglist.le_next)
+			if (checkctty == 0 || p->p_flag & P_CONTROLT)
+				psignal(p, signum);
+}
+
+/*
+ * Send a signal caused by a trap to the current process.
+ * If it will be caught immediately, deliver it with correct code.
+ * Otherwise, post it normally.
+ */
+void
+trapsignal(p, signum, code)
+	struct proc *p;
+	register int signum;
+	u_long code;
+{
+	register struct sigacts *ps = p->p_sigacts;
+	int mask;
+
+	mask = sigmask(signum);
+	if ((p->p_flag & P_TRACED) == 0 && (p->p_sigcatch & mask) != 0 &&
+	    (p->p_sigmask & mask) == 0) {
+		p->p_stats->p_ru.ru_nsignals++;
+#ifdef KTRACE
+		if (KTRPOINT(p, KTR_PSIG))
+			ktrpsig(p->p_tracep, signum, ps->ps_sigact[signum], 
+				p->p_sigmask, code);
+#endif
+		(*p->p_emul->e_sendsig)(ps->ps_sigact[signum], signum,
+		    p->p_sigmask, code);
+		p->p_sigmask |= ps->ps_catchmask[signum];
+		if ((ps->ps_sigreset & mask) != 0) {
+			p->p_sigcatch &= ~mask;
+			if (signum != SIGCONT && sigprop[signum] & SA_IGNORE)
+				p->p_sigignore |= mask;
+			ps->ps_sigact[signum] = SIG_DFL;
+		}
+	} else {
+		ps->ps_code = code;	/* XXX for core dump/debugger */
+		psignal(p, signum);
+	}
+}
+
+/*
+ * Send the signal to the process.  If the signal has an action, the action
+ * is usually performed by the target process rather than the caller; we add
+ * the signal to the set of pending signals for the process.
+ *
+ * Exceptions:
+ *   o When a stop signal is sent to a sleeping process that takes the
+ *     default action, the process is stopped without awakening it.
+ *   o SIGCONT restarts stopped processes (or puts them back to sleep)
+ *     regardless of the signal action (eg, blocked or ignored).
+ *
+ * Other ignored signals are discarded immediately.
+ */
+void
+psignal(p, signum)
+	register struct proc *p;
+	register int signum;
+{
+	register int s, prop;
+	register sig_t action;
+	int mask;
+
+	if ((u_int)signum >= NSIG || signum == 0)
+		panic("psignal signal number");
+	mask = sigmask(signum);
+	prop = sigprop[signum];
+
+	/*
+	 * If proc is traced, always give parent a chance.
+	 */
+	if (p->p_flag & P_TRACED)
+		action = SIG_DFL;
+	else {
+		/*
+		 * If the signal is being ignored,
+		 * then we forget about it immediately.
+		 * (Note: we don't set SIGCONT in p_sigignore,
+		 * and if it is set to SIG_IGN,
+		 * action will be SIG_DFL here.)
+		 */
+		if (p->p_sigignore & mask)
+			return;
+		if (p->p_sigmask & mask)
+			action = SIG_HOLD;
+		else if (p->p_sigcatch & mask)
+			action = SIG_CATCH;
+		else {
+			action = SIG_DFL;
+
+			if (prop & SA_KILL && p->p_nice > NZERO)
+				p->p_nice = NZERO;
+
+			/*
+			 * If sending a tty stop signal to a member of an
+			 * orphaned process group, discard the signal here if
+			 * the action is default; don't stop the process below
+			 * if sleeping, and don't clear any pending SIGCONT.
+			 */
+			if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0)
+				return;
+		}
+	}
+
+	if (prop & SA_CONT)
+		p->p_siglist &= ~stopsigmask;
+
+	if (prop & SA_STOP)
+		p->p_siglist &= ~contsigmask;
+
+	p->p_siglist |= mask;
+
+	/*
+	 * Defer further processing for signals which are held,
+	 * except that stopped processes must be continued by SIGCONT.
+	 */
+	if (action == SIG_HOLD && ((prop & SA_CONT) == 0 || p->p_stat != SSTOP))
+		return;
+	s = splhigh();
+	switch (p->p_stat) {
+
+	case SSLEEP:
+		/*
+		 * If process is sleeping uninterruptibly
+		 * we can't interrupt the sleep... the signal will
+		 * be noticed when the process returns through
+		 * trap() or syscall().
+		 */
+		if ((p->p_flag & P_SINTR) == 0)
+			goto out;
+		/*
+		 * Process is sleeping and traced... make it runnable
+		 * so it can discover the signal in issignal() and stop
+		 * for the parent.
+		 */
+		if (p->p_flag & P_TRACED)
+			goto run;
+		/*
+		 * If SIGCONT is default (or ignored) and process is
+		 * asleep, we are finished; the process should not
+		 * be awakened.
+		 */
+		if ((prop & SA_CONT) && action == SIG_DFL) {
+			p->p_siglist &= ~mask;
+			goto out;
+		}
+		/*
+		 * When a sleeping process receives a stop
+		 * signal, process immediately if possible.
+		 */
+		if ((prop & SA_STOP) && action == SIG_DFL) {
+			/*
+			 * If a child holding parent blocked,
+			 * stopping could cause deadlock.
+			 */
+			if (p->p_flag & P_PPWAIT)
+				goto out;
+			p->p_siglist &= ~mask;
+			p->p_xstat = signum;
+			if ((p->p_pptr->p_flag & P_NOCLDSTOP) == 0)
+				psignal(p->p_pptr, SIGCHLD);
+			stop(p);
+			goto out;
+		}
+		/*
+		 * All other (caught or default) signals
+		 * cause the process to run.
+		 */
+		goto runfast;
+		/*NOTREACHED*/
+
+	case SSTOP:
+		/*
+		 * If traced process is already stopped,
+		 * then no further action is necessary.
+		 */
+		if (p->p_flag & P_TRACED)
+			goto out;
+
+		/*
+		 * Kill signal always sets processes running.
+		 */
+		if (signum == SIGKILL)
+			goto runfast;
+
+		if (prop & SA_CONT) {
+			/*
+			 * If SIGCONT is default (or ignored), we continue the
+			 * process but don't leave the signal in p_siglist, as
+			 * it has no further action.  If SIGCONT is held, we
+			 * continue the process and leave the signal in
+			 * p_siglist.  If the process catches SIGCONT, let it
+			 * handle the signal itself.  If it isn't waiting on
+			 * an event, then it goes back to run state.
+			 * Otherwise, process goes back to sleep state.
+			 */
+			if (action == SIG_DFL)
+				p->p_siglist &= ~mask;
+			if (action == SIG_CATCH)
+				goto runfast;
+			if (p->p_wchan == 0)
+				goto run;
+			p->p_stat = SSLEEP;
+			goto out;
+		}
+
+		if (prop & SA_STOP) {
+			/*
+			 * Already stopped, don't need to stop again.
+			 * (If we did the shell could get confused.)
+			 */
+			p->p_siglist &= ~mask;		/* take it away */
+			goto out;
+		}
+
+		/*
+		 * If process is sleeping interruptibly, then simulate a
+		 * wakeup so that when it is continued, it will be made
+		 * runnable and can look at the signal.  But don't make
+		 * the process runnable, leave it stopped.
+		 */
+		if (p->p_wchan && p->p_flag & P_SINTR)
+			unsleep(p);
+		goto out;
+
+	default:
+		/*
+		 * SRUN, SIDL, SZOMB do nothing with the signal,
+		 * other than kicking ourselves if we are running.
+		 * It will either never be noticed, or noticed very soon.
+		 */
+		if (p == curproc)
+			signotify(p);
+		goto out;
+	}
+	/*NOTREACHED*/
+
+runfast:
+	/*
+	 * Raise priority to at least PUSER.
+	 */
+	if (p->p_priority > PUSER)
+		p->p_priority = PUSER;
+run:
+	setrunnable(p);
+out:
+	splx(s);
+}
+
+/*
+ * If the current process has received a signal (should be caught or cause
+ * termination, should interrupt current syscall), return the signal number.
+ * Stop signals with default action are processed immediately, then cleared;
+ * they aren't returned.  This is checked after each entry to the system for
+ * a syscall or trap (though this can usually be done without calling issignal
+ * by checking the pending signal masks in the CURSIG macro.) The normal call
+ * sequence is
+ *
+ *	while (signum = CURSIG(curproc))
+ *		postsig(signum);
+ */
+int
+issignal(p)
+	register struct proc *p;
+{
+	register int signum, mask, prop;
+
+	for (;;) {
+		mask = p->p_siglist & ~p->p_sigmask;
+		if (p->p_flag & P_PPWAIT)
+			mask &= ~stopsigmask;
+		if (mask == 0)	 	/* no signal to send */
+			return (0);
+		signum = ffs((long)mask);
+		mask = sigmask(signum);
+		p->p_siglist &= ~mask;		/* take the signal! */
+
+		/*
+		 * We should see pending but ignored signals
+		 * only if P_TRACED was on when they were posted.
+		 */
+		if (mask & p->p_sigignore && (p->p_flag & P_TRACED) == 0)
+			continue;
+
+		if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) {
+			/*
+			 * If traced, always stop, and stay
+			 * stopped until released by the debugger.
+			 */
+			p->p_xstat = signum;
+
+			if (p->p_flag & P_FSTRACE) {
+#ifdef	PROCFS
+				/* procfs debugging */
+				p->p_stat = SSTOP;
+				wakeup((caddr_t)p);
+				mi_switch();
+#else
+				panic("procfs debugging");
+#endif
+			} else {
+				/* ptrace debugging */
+				psignal(p->p_pptr, SIGCHLD);
+				do {
+					stop(p);
+					mi_switch();
+				} while (!trace_req(p) && p->p_flag & P_TRACED);
+			}
+
+			/*
+			 * If we are no longer being traced, or the parent
+			 * didn't give us a signal, look for more signals.
+			 */
+			if ((p->p_flag & P_TRACED) == 0 || p->p_xstat == 0)
+				continue;
+
+			/*
+			 * If the new signal is being masked, look for other
+			 * signals.
+			 */
+			signum = p->p_xstat;
+			mask = sigmask(signum);
+			if ((p->p_sigmask & mask) != 0)
+				continue;
+			p->p_siglist &= ~mask;		/* take the signal! */
+		}
+
+		prop = sigprop[signum];
+
+		/*
+		 * Decide whether the signal should be returned.
+		 * Return the signal's number, or fall through
+		 * to clear it from the pending mask.
+		 */
+		switch ((long)p->p_sigacts->ps_sigact[signum]) {
+
+		case (long)SIG_DFL:
+			/*
+			 * Don't take default actions on system processes.
+			 */
+			if (p->p_pid <= 1) {
+#ifdef DIAGNOSTIC
+				/*
+				 * Are you sure you want to ignore SIGSEGV
+				 * in init? XXX
+				 */
+				printf("Process (pid %d) got signal %d\n",
+				    p->p_pid, signum);
+#endif
+				break;		/* == ignore */
+			}
+			/*
+			 * If there is a pending stop signal to process
+			 * with default action, stop here,
+			 * then clear the signal.  However,
+			 * if process is member of an orphaned
+			 * process group, ignore tty stop signals.
+			 */
+			if (prop & SA_STOP) {
+				if (p->p_flag & P_TRACED ||
+		    		    (p->p_pgrp->pg_jobc == 0 &&
+				    prop & SA_TTYSTOP))
+					break;	/* == ignore */
+				p->p_xstat = signum;
+				if ((p->p_pptr->p_flag & P_NOCLDSTOP) == 0)
+					psignal(p->p_pptr, SIGCHLD);
+				stop(p);
+				mi_switch();
+				break;
+			} else if (prop & SA_IGNORE) {
+				/*
+				 * Except for SIGCONT, shouldn't get here.
+				 * Default action is to ignore; drop it.
+				 */
+				break;		/* == ignore */
+			} else
+				goto keep;
+			/*NOTREACHED*/
+
+		case (long)SIG_IGN:
+			/*
+			 * Masking above should prevent us ever trying
+			 * to take action on an ignored signal other
+			 * than SIGCONT, unless process is traced.
+			 */
+			if ((prop & SA_CONT) == 0 &&
+			    (p->p_flag & P_TRACED) == 0)
+				printf("issignal\n");
+			break;		/* == ignore */
+
+		default:
+			/*
+			 * This signal has an action, let
+			 * postsig() process it.
+			 */
+			goto keep;
+		}
+	}
+	/* NOTREACHED */
+
+keep:
+	p->p_siglist |= mask;		/* leave the signal for later */
+	return (signum);
+}
+
+/*
+ * Put the argument process into the stopped state and notify the parent
+ * via wakeup.  Signals are handled elsewhere.  The process must not be
+ * on the run queue.
+ */
+void
+stop(p)
+	register struct proc *p;
+{
+
+	p->p_stat = SSTOP;
+	p->p_flag &= ~P_WAITED;
+	wakeup((caddr_t)p->p_pptr);
+}
+
+/*
+ * Take the action for the specified signal
+ * from the current set of pending signals.
+ */
+void
+postsig(signum)
+	register int signum;
+{
+	register struct proc *p = curproc;
+	register struct sigacts *ps = p->p_sigacts;
+	register sig_t action;
+	u_long code;
+	int mask, returnmask;
+
+#ifdef DIAGNOSTIC
+	if (signum == 0)
+		panic("postsig");
+#endif
+	mask = sigmask(signum);
+	p->p_siglist &= ~mask;
+	action = ps->ps_sigact[signum];
+#ifdef KTRACE
+	if (KTRPOINT(p, KTR_PSIG))
+		ktrpsig(p->p_tracep,
+		    signum, action, ps->ps_flags & SAS_OLDMASK ?
+		    ps->ps_oldmask : p->p_sigmask, 0);
+#endif
+	if (action == SIG_DFL) {
+		/*
+		 * Default action, where the default is to kill
+		 * the process.  (Other cases were ignored above.)
+		 */
+		sigexit(p, signum);
+		/* NOTREACHED */
+	} else {
+		/*
+		 * If we get here, the signal must be caught.
+		 */
+#ifdef DIAGNOSTIC
+		if (action == SIG_IGN || (p->p_sigmask & mask))
+			panic("postsig action");
+#endif
+		/*
+		 * Set the new mask value and also defer further
+		 * occurences of this signal.
+		 *
+		 * Special case: user has done a sigpause.  Here the
+		 * current mask is not of interest, but rather the
+		 * mask from before the sigpause is what we want
+		 * restored after the signal processing is completed.
+		 */
+		(void) splhigh();
+		if (ps->ps_flags & SAS_OLDMASK) {
+			returnmask = ps->ps_oldmask;
+			ps->ps_flags &= ~SAS_OLDMASK;
+		} else
+			returnmask = p->p_sigmask;
+		p->p_sigmask |= ps->ps_catchmask[signum];
+		if ((ps->ps_sigreset & mask) != 0) {
+			p->p_sigcatch &= ~mask;
+			if (signum != SIGCONT && sigprop[signum] & SA_IGNORE)
+				p->p_sigignore |= mask;
+			ps->ps_sigact[signum] = SIG_DFL;
+		}
+		(void) spl0();
+		p->p_stats->p_ru.ru_nsignals++;
+		if (ps->ps_sig != signum) {
+			code = 0;
+		} else {
+			code = ps->ps_code;
+			ps->ps_code = 0;
+		}
+		(*p->p_emul->e_sendsig)(action, signum, returnmask, code);
+	}
+}
+
+/*
+ * Kill the current process for stated reason.
+ */
+killproc(p, why)
+	struct proc *p;
+	char *why;
+{
+
+	log(LOG_ERR, "pid %d was killed: %s\n", p->p_pid, why);
+	uprintf("sorry, pid %d was killed: %s\n", p->p_pid, why);
+	psignal(p, SIGKILL);
+}
+
+/*
+ * Force the current process to exit with the specified signal, dumping core
+ * if appropriate.  We bypass the normal tests for masked and caught signals,
+ * allowing unrecoverable failures to terminate the process without changing
+ * signal state.  Mark the accounting record with the signal termination.
+ * If dumping core, save the signal number for the debugger.  Calls exit and
+ * does not return.
+ */
+int
+sigexit(p, signum)
+	register struct proc *p;
+	int signum;
+{
+
+	p->p_acflag |= AXSIG;
+	if (sigprop[signum] & SA_CORE) {
+		p->p_sigacts->ps_sig = signum;
+		if (coredump(p) == 0)
+			signum |= WCOREFLAG;
+	}
+	exit1(p, W_EXITCODE(0, signum));
+	/* NOTREACHED */
+}
+
+/*
+ * Dump core, into a file named "progname.core", unless the process was
+ * setuid/setgid.
+ */
+int
+coredump(p)
+	register struct proc *p;
+{
+	register struct vnode *vp;
+	register struct pcred *pcred = p->p_cred;
+	register struct ucred *cred = pcred->pc_ucred;
+	register struct vmspace *vm = p->p_vmspace;
+	struct nameidata nd;
+	struct vattr vattr;
+	int error, error1;
+	char name[MAXCOMLEN+6];		/* progname.core */
+	struct core core;
+
+	if (pcred->p_svuid != pcred->p_ruid || pcred->p_svgid != pcred->p_rgid)
+		return (EFAULT);
+	if (USPACE + ctob(vm->vm_dsize + vm->vm_ssize) >=
+	    p->p_rlimit[RLIMIT_CORE].rlim_cur)
+		return (EFAULT);
+	sprintf(name, "%s.core", p->p_comm);
+	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, name, p);
+	if (error = vn_open(&nd, O_CREAT | FWRITE, S_IRUSR | S_IWUSR))
+		return (error);
+	vp = nd.ni_vp;
+
+	/* Don't dump to non-regular files or files with links. */
+	if (vp->v_type != VREG ||
+	    VOP_GETATTR(vp, &vattr, cred, p) || vattr.va_nlink != 1) {
+		error = EFAULT;
+		goto out;
+	}
+	VATTR_NULL(&vattr);
+	vattr.va_size = 0;
+	VOP_LEASE(vp, p, cred, LEASE_WRITE);
+	VOP_SETATTR(vp, &vattr, cred, p);
+	p->p_acflag |= ACORE;
+	bcopy(p, &p->p_addr->u_kproc.kp_proc, sizeof(struct proc));
+	fill_eproc(p, &p->p_addr->u_kproc.kp_eproc);
+
+	core.c_midmag = 0;
+	strncpy(core.c_name, p->p_comm, MAXCOMLEN);
+	core.c_nseg = 0;
+	core.c_signo = p->p_sigacts->ps_sig;
+	core.c_ucode = p->p_sigacts->ps_code;
+	core.c_cpusize = 0;
+	core.c_tsize = (u_long)ctob(vm->vm_tsize);
+	core.c_dsize = (u_long)ctob(vm->vm_dsize);
+	core.c_ssize = (u_long)round_page(ctob(vm->vm_ssize));
+	error = cpu_coredump(p, vp, cred, &core);
+	if (error)
+		goto out;
+	if (core.c_midmag == 0) {
+		/* XXX
+		 * cpu_coredump() didn't bother to set the magic; assume
+		 * this is a request to do a traditional dump. cpu_coredump()
+		 * is still responsible for setting sensible values in
+		 * the core header.
+		 */
+		if (core.c_cpusize == 0)
+			core.c_cpusize = USPACE; /* Just in case */
+		error = vn_rdwr(UIO_WRITE, vp, vm->vm_daddr,
+		    (int)core.c_dsize,
+		    (off_t)core.c_cpusize, UIO_USERSPACE,
+		    IO_NODELOCKED|IO_UNIT, cred, (int *) NULL, p);
+		if (error)
+			goto out;
+		error = vn_rdwr(UIO_WRITE, vp,
+		    (caddr_t) trunc_page(USRSTACK - ctob(vm->vm_ssize)),
+		    core.c_ssize,
+		    (off_t)(core.c_cpusize + core.c_dsize), UIO_USERSPACE,
+		    IO_NODELOCKED|IO_UNIT, cred, (int *) NULL, p);
+	} else {
+		/*
+		 * vm_coredump() spits out all appropriate segments.
+		 * All that's left to do is to write the core header.
+		 */
+		error = vm_coredump(p, vp, cred, &core);
+		if (error)
+			goto out;
+		error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&core,
+		    (int)core.c_hdrsize, (off_t)0,
+		    UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred, (int *) NULL, p);
+	}
+out:
+	VOP_UNLOCK(vp);
+	error1 = vn_close(vp, FWRITE, cred, p);
+	if (error == 0)
+		error = error1;
+	return (error);
+}
+
+/*
+ * Nonexistent system call-- signal process (may want to handle it).
+ * Flag error in case process won't see signal immediately (blocked or ignored).
+ */
+/* ARGSUSED */
+int
+sys_nosys(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+
+	psignal(p, SIGSYS);
+	return (ENOSYS);
+}