Changes to allow event-based process monitoring and control.

15 files changed, 326 insertions, 20 deletions

diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index 8c45d1f..f936fd6 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
- *	$Id: trap.c,v 1.117 1997/12/04 14:35:40 jkh Exp $
+ *	$Id: trap.c,v 1.118 1997/12/04 21:21:26 jmg Exp $
  */
 
 /*
@@ -50,6 +50,7 @@
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/proc.h>
+#include <sys/pioctl.h>
 #include <sys/kernel.h>
 #include <sys/resourcevar.h>
 #include <sys/signalvar.h>
@@ -987,6 +988,8 @@ syscall(frame)
 	p->p_retval[0] = 0;
 	p->p_retval[1] = frame.tf_edx;
 
+	STOPEVENT(p, S_SCE, callp->sy_narg);
+
 	error = (*callp->sy_call)(p, args);
 
 	switch (error) {
@@ -1037,6 +1040,14 @@ bad:
 	if (KTRPOINT(p, KTR_SYSRET))
 		ktrsysret(p->p_tracep, code, error, p->p_retval[0]);
 #endif
+
+	/*
+	 * This works because errno is findable through the
+	 * register set.  If we ever support an emulation where this
+	 * is not the case, this code will need to be revisited.
+	 */
+	STOPEVENT(p, S_SCX, code);
+
 }
 
 /*
diff --git a/sys/fs/procfs/procfs_subr.c b/sys/fs/procfs/procfs_subr.c
index 42e9bf4..b77489b 100644
--- a/sys/fs/procfs/procfs_subr.c
+++ b/sys/fs/procfs/procfs_subr.c
@@ -36,7 +36,7 @@
  *
  *	@(#)procfs_subr.c	8.6 (Berkeley) 5/14/95
  *
- *	$Id: procfs_subr.c,v 1.16 1997/06/26 16:12:53 alex Exp $
+ *	$Id: procfs_subr.c,v 1.17 1997/08/02 14:32:18 bde Exp $
  */
 
 #include <sys/param.h>
@@ -351,3 +351,14 @@ vfs_findname(nm, buf, buflen)
 
 	return (0);
 }
+
+void
+procfs_exit(pid_t pid)
+{
+	struct pfsnode *pfs;
+
+	for (pfs = pfshead; pfs ; pfs = pfs->pfs_next) {
+		if (pfs->pfs_pid == pid)
+			vgone(PFSTOV(pfs));
+	}
+}
diff --git a/sys/fs/procfs/procfs_vnops.c b/sys/fs/procfs/procfs_vnops.c
index 284242f..a1789da 100644
--- a/sys/fs/procfs/procfs_vnops.c
+++ b/sys/fs/procfs/procfs_vnops.c
@@ -36,7 +36,7 @@
  *
  *	@(#)procfs_vnops.c	8.18 (Berkeley) 5/21/95
  *
- *	$Id: procfs_vnops.c,v 1.42 1997/11/07 08:53:15 phk Exp $
+ *	$Id: procfs_vnops.c,v 1.43 1997/12/05 19:55:47 bde Exp $
  */
 
 /*
@@ -56,6 +56,7 @@
 #include <sys/dirent.h>
 #include <machine/reg.h>
 #include <miscfs/procfs/procfs.h>
+#include <sys/pioctl.h>
 
 static int	procfs_abortop __P((struct vop_abortop_args *));
 static int	procfs_access __P((struct vop_access_args *));
@@ -64,6 +65,7 @@ static int	procfs_bmap __P((struct vop_bmap_args *));
 static int	procfs_close __P((struct vop_close_args *));
 static int	procfs_getattr __P((struct vop_getattr_args *));
 static int	procfs_inactive __P((struct vop_inactive_args *));
+static int	procfs_ioctl __P((struct vop_ioctl_args *));
 static int	procfs_lookup __P((struct vop_lookup_args *));
 static int	procfs_open __P((struct vop_open_args *));
 static int	procfs_print __P((struct vop_print_args *));
@@ -185,6 +187,79 @@ procfs_close(ap)
 }
 
 /*
+ * do an ioctl operation on a pfsnode (vp).
+ * (vp) is not locked on entry or exit.
+ */
+static int
+procfs_ioctl(ap)
+	struct vop_ioctl_args *ap;
+{
+	struct pfsnode *pfs = VTOPFS(ap->a_vp);
+	struct proc *procp;
+	int error;
+	int signo;
+	struct procfs_status *psp;
+
+	procp = pfind(pfs->pfs_pid);
+	if (procp == NULL) {
+		return ENOTTY;
+	}
+
+	switch (ap->a_command) {
+	case PIOCBIS:
+	  procp->p_stops |= *(unsigned int*)ap->a_data;
+	  break;
+	case PIOCBIC:
+	  procp->p_stops &= ~*(unsigned int*)ap->a_data;
+	  break;
+	case PIOCSFL:
+	  procp->p_pfsflags = (unsigned char)*(unsigned int*)ap->a_data;
+	  *(unsigned int*)ap->a_data = procp->p_stops;
+	  break;
+	case PIOCSTATUS:
+	  psp = (struct procfs_status *)ap->a_data;
+	  psp->state = (procp->p_step == 0);
+	  psp->flags = procp->p_pfsflags;
+	  psp->events = procp->p_stops;
+	  if (procp->p_step) {
+	    psp->why = procp->p_stype;
+	    psp->val = procp->p_xstat;
+	  } else {
+	    psp->why = psp->val = 0;	/* Not defined values */
+	  }
+	  break;
+	case PIOCWAIT:
+	  psp = (struct procfs_status *)ap->a_data;
+	  if (procp->p_step == 0) {
+	    error = tsleep(&procp->p_stype, PWAIT | PCATCH, "piocwait", 0);
+	    if (error)
+	      return error;
+	  }
+	  psp->state = 1;	/* It stopped */
+	  psp->flags = procp->p_pfsflags;
+	  psp->events = procp->p_stops;
+	  psp->why = procp->p_stype;	/* why it stopped */
+	  psp->val = procp->p_xstat;	/* any extra info */
+	  break;
+	case PIOCCONT:	/* Restart a proc */
+	  if (procp->p_step == 0)
+	    return EINVAL;	/* Can only start a stopped process */
+	  if (ap->a_data && (signo = *(int*)ap->a_data)) {
+	    if (signo >= NSIG || signo <= 0)
+	      return EINVAL;
+	    if (error = psignal(procp, signo))
+	      return error;
+	  }
+	  procp->p_step = 0;
+	  wakeup(&procp->p_step);
+	  break;
+	default:
+	  return (ENOTTY);
+	}
+	return 0;
+}
+
+/*
  * do block mapping for pfsnode (vp).
  * since we don't use the buffer cache
  * for procfs this function should never
@@ -909,6 +984,7 @@ static struct vnodeopv_entry_desc procfs_vnodeop_entries[] = {
 	{ &vop_setattr_desc,		(vop_t *) procfs_setattr },
 	{ &vop_symlink_desc,		(vop_t *) procfs_badop },
 	{ &vop_write_desc,		(vop_t *) procfs_rw },
+	{ &vop_ioctl_desc,		(vop_t *) procfs_ioctl },
 	{ NULL, NULL }
 };
 static struct vnodeopv_desc procfs_vnodeop_opv_desc =
diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c
index 8c45d1f..f936fd6 100644
--- a/sys/i386/i386/trap.c
+++ b/sys/i386/i386/trap.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
- *	$Id: trap.c,v 1.117 1997/12/04 14:35:40 jkh Exp $
+ *	$Id: trap.c,v 1.118 1997/12/04 21:21:26 jmg Exp $
  */
 
 /*
@@ -50,6 +50,7 @@
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/proc.h>
+#include <sys/pioctl.h>
 #include <sys/kernel.h>
 #include <sys/resourcevar.h>
 #include <sys/signalvar.h>
@@ -987,6 +988,8 @@ syscall(frame)
 	p->p_retval[0] = 0;
 	p->p_retval[1] = frame.tf_edx;
 
+	STOPEVENT(p, S_SCE, callp->sy_narg);
+
 	error = (*callp->sy_call)(p, args);
 
 	switch (error) {
@@ -1037,6 +1040,14 @@ bad:
 	if (KTRPOINT(p, KTR_SYSRET))
 		ktrsysret(p->p_tracep, code, error, p->p_retval[0]);
 #endif
+
+	/*
+	 * This works because errno is findable through the
+	 * register set.  If we ever support an emulation where this
+	 * is not the case, this code will need to be revisited.
+	 */
+	STOPEVENT(p, S_SCX, code);
+
 }
 
 /*
diff --git a/sys/kern/init_main.c b/sys/kern/init_main.c
index fa381e2..e56531e 100644
--- a/sys/kern/init_main.c
+++ b/sys/kern/init_main.c
@@ -39,7 +39,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)init_main.c	8.9 (Berkeley) 1/21/94
- * $Id: init_main.c,v 1.75 1997/11/24 18:35:04 bde Exp $
+ * $Id: init_main.c,v 1.76 1997/11/25 07:07:41 julian Exp $
  */
 
 #include "opt_devfs.h"
@@ -415,6 +415,12 @@ proc0_init(dummy)
 	 * Charge root for one process.
 	 */
 	(void)chgproccnt(0, 1);
+
+	/*
+	 * Initialize the procfs flags (to 0, of course)
+	 */
+	p->p_stops = p->p_stype = p->p_step = 0;
+
 }
 SYSINIT(p0init, SI_SUB_INTRINSIC, SI_ORDER_FIRST, proc0_init, NULL)
 
diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index bdad7d9..4d4f05a 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: kern_exec.c,v 1.67 1997/10/15 18:28:34 guido Exp $
+ *	$Id: kern_exec.c,v 1.68 1997/11/06 19:29:08 phk Exp $
  */
 
 #include <sys/param.h>
@@ -40,6 +40,7 @@
 #include <sys/imgact_elf.h>
 #include <sys/wait.h>
 #include <sys/proc.h>
+#include <sys/pioctl.h>
 #include <sys/malloc.h>
 #include <sys/namei.h>
 #include <sys/sysent.h>
@@ -338,6 +339,8 @@ interpret:
 	 * If tracing the process, trap to debugger so breakpoints
 	 * 	can be set before the program executes.
 	 */
+	STOPEVENT(p, S_EXEC, 0);
+
 	if (p->p_flag & P_TRACED)
 		psignal(p, SIGTRAP);
 
diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index dd1a54e..d282d22 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)kern_exit.c	8.7 (Berkeley) 2/12/94
- * $Id: kern_exit.c,v 1.59 1997/11/06 19:29:08 phk Exp $
+ * $Id: kern_exit.c,v 1.60 1997/11/20 19:09:43 bde Exp $
  */
 
 #include "opt_ktrace.h"
@@ -46,6 +46,7 @@
 #include <sys/sysproto.h>
 #include <sys/malloc.h>
 #include <sys/proc.h>
+#include <sys/pioctl.h>
 #include <sys/tty.h>
 #include <sys/wait.h>
 #include <sys/vnode.h>
@@ -113,6 +114,7 @@ exit1(p, rv)
 	register struct proc *q, *nq;
 	register struct vmspace *vm;
 	ele_p ep = exit_list;
+	extern void procfs_exit(pid_t);
 
 	if (p->p_pid == 1) {
 		printf("init died (signal %d, exit %d)\n",
@@ -155,6 +157,14 @@ exit1(p, rv)
 #ifdef PGINPROF
 	vmsizmon();
 #endif
+	STOPEVENT(p, S_EXIT, rv);
+
+	/*
+	 * Now that we're back from stopevent(), force a close
+	 * of all open procfs files for this process.
+	 */
+	procfs_exit(p->p_pid);
+
 	/* 
 	 * Check if any LKMs need anything done at process exit.
 	 * e.g. SYSV IPC stuff
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 8a378a1..3200080 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)kern_sig.c	8.7 (Berkeley) 4/18/94
- * $Id: kern_sig.c,v 1.34 1997/09/13 19:42:12 joerg Exp $
+ * $Id: kern_sig.c,v 1.35 1997/11/06 19:29:14 phk Exp $
  */
 
 #include "opt_ktrace.h"
@@ -49,6 +49,7 @@
 #include <sys/namei.h>
 #include <sys/vnode.h>
 #include <sys/proc.h>
+#include <sys/pioctl.h>
 #include <sys/systm.h>
 #include <sys/acct.h>
 #include <sys/fcntl.h>
@@ -743,15 +744,19 @@ psignal(p, signum)
 	register sig_t action;
 	int mask;
 
-	if ((u_int)signum >= NSIG || signum == 0)
+	if ((u_int)signum >= NSIG || signum == 0) {
+		printf("psignal: signum %d\n", signum);
 		panic("psignal signal number");
+	}
 	mask = sigmask(signum);
 	prop = sigprop[signum];
 
 	/*
-	 * If proc is traced, always give parent a chance.
+	 * If proc is traced, always give parent a chance;
+	 * if signal event is tracked by procfs, give *that*
+	 * a chance, as well.
 	 */
-	if (p->p_flag & P_TRACED)
+	if ((p->p_flag & P_TRACED) || (p->p_stops & S_SIG))
 		action = SIG_DFL;
 	else {
 		/*
@@ -948,6 +953,8 @@ issignal(p)
 	register int signum, mask, prop;
 
 	for (;;) {
+		int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG);
+
 		mask = p->p_siglist & ~p->p_sigmask;
 		if (p->p_flag & P_PPWAIT)
 			mask &= ~stopsigmask;
@@ -956,11 +963,14 @@ issignal(p)
 		signum = ffs((long)mask);
 		mask = sigmask(signum);
 		prop = sigprop[signum];
+
+		STOPEVENT(p, S_SIG, signum);
+
 		/*
 		 * 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) {
+		if ((mask & p->p_sigignore) && (traced == 0)) {
 			p->p_siglist &= ~mask;
 			continue;
 		}
@@ -974,7 +984,8 @@ issignal(p)
 			do {
 				stop(p);
 				mi_switch();
-			} while (!trace_req(p) && p->p_flag & P_TRACED);
+			} while (!trace_req(p)
+				 && p->p_flag & P_TRACED);
 
 			/*
 			 * If the traced bit got turned off, go back up
@@ -1118,6 +1129,8 @@ postsig(signum)
 		    signum, action, ps->ps_flags & SAS_OLDMASK ?
 		    ps->ps_oldmask : p->p_sigmask, 0);
 #endif
+	STOPEVENT(p, S_SIG, signum);
+
 	if (action == SIG_DFL) {
 		/*
 		 * Default action, where the default is to kill
@@ -1236,6 +1249,8 @@ coredump(p)
 	int error, error1;
 	char name[MAXCOMLEN+6];		/* progname.core */
 
+	STOPEVENT(p, S_CORE, 0);
+
 	if (p->p_flag & P_SUGID)
 		return (EFAULT);
 	if (ctob(UPAGES + vm->vm_dsize + vm->vm_ssize) >=
diff --git a/sys/kern/subr_trap.c b/sys/kern/subr_trap.c
index 8c45d1f..f936fd6 100644
--- a/sys/kern/subr_trap.c
+++ b/sys/kern/subr_trap.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
- *	$Id: trap.c,v 1.117 1997/12/04 14:35:40 jkh Exp $
+ *	$Id: trap.c,v 1.118 1997/12/04 21:21:26 jmg Exp $
  */
 
 /*
@@ -50,6 +50,7 @@
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/proc.h>
+#include <sys/pioctl.h>
 #include <sys/kernel.h>
 #include <sys/resourcevar.h>
 #include <sys/signalvar.h>
@@ -987,6 +988,8 @@ syscall(frame)
 	p->p_retval[0] = 0;
 	p->p_retval[1] = frame.tf_edx;
 
+	STOPEVENT(p, S_SCE, callp->sy_narg);
+
 	error = (*callp->sy_call)(p, args);
 
 	switch (error) {
@@ -1037,6 +1040,14 @@ bad:
 	if (KTRPOINT(p, KTR_SYSRET))
 		ktrsysret(p->p_tracep, code, error, p->p_retval[0]);
 #endif
+
+	/*
+	 * This works because errno is findable through the
+	 * register set.  If we ever support an emulation where this
+	 * is not the case, this code will need to be revisited.
+	 */
+	STOPEVENT(p, S_SCX, code);
+
 }
 
 /*
diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index 28007f72..c289115 100644
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -28,7 +28,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: sys_process.c,v 1.31 1997/11/06 19:29:22 phk Exp $
+ *	$Id: sys_process.c,v 1.32 1997/11/12 12:28:12 tegge Exp $
  */
 
 #include <sys/param.h>
@@ -503,3 +503,22 @@ trace_req(p)
 {
 	return 1;
 }
+
+/*
+ * stopevent()
+ * Stop a process because of a procfs event;
+ * stay stopped until p->p_step is cleared
+ * (cleared by PIOCCONT in procfs).
+ */
+
+void
+stopevent(struct proc *p, unsigned int event, unsigned int val) {
+	p->p_step = 1;
+
+	do {
+		p->p_xstat = val;
+		p->p_stype = event;	/* Which event caused the stop? */
+		wakeup(&p->p_stype);	/* Wake up any PIOCWAIT'ing procs */
+		tsleep(&p->p_step, PWAIT, "stopevent", 0);
+	} while (p->p_step);
+}
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index dd12e9f..58dfad5 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)vfs_vnops.c	8.2 (Berkeley) 1/21/94
- * $Id: vfs_vnops.c,v 1.41 1997/11/07 08:53:11 phk Exp $
+ * $Id: vfs_vnops.c,v 1.42 1997/11/29 01:33:10 dyson Exp $
  */
 
 #include <sys/param.h>
@@ -454,8 +454,9 @@ vn_ioctl(fp, com, data, p)
 		/* fall into ... */
 
 	default:
+#if 0
 		return (ENOTTY);
-
+#endif
 	case VFIFO:
 	case VCHR:
 	case VBLK:
diff --git a/sys/miscfs/procfs/procfs_subr.c b/sys/miscfs/procfs/procfs_subr.c
index 42e9bf4..b77489b 100644
--- a/sys/miscfs/procfs/procfs_subr.c
+++ b/sys/miscfs/procfs/procfs_subr.c
@@ -36,7 +36,7 @@
  *
  *	@(#)procfs_subr.c	8.6 (Berkeley) 5/14/95
  *
- *	$Id: procfs_subr.c,v 1.16 1997/06/26 16:12:53 alex Exp $
+ *	$Id: procfs_subr.c,v 1.17 1997/08/02 14:32:18 bde Exp $
  */
 
 #include <sys/param.h>
@@ -351,3 +351,14 @@ vfs_findname(nm, buf, buflen)
 
 	return (0);
 }
+
+void
+procfs_exit(pid_t pid)
+{
+	struct pfsnode *pfs;
+
+	for (pfs = pfshead; pfs ; pfs = pfs->pfs_next) {
+		if (pfs->pfs_pid == pid)
+			vgone(PFSTOV(pfs));
+	}
+}
diff --git a/sys/miscfs/procfs/procfs_vnops.c b/sys/miscfs/procfs/procfs_vnops.c
index 284242f..a1789da 100644
--- a/sys/miscfs/procfs/procfs_vnops.c
+++ b/sys/miscfs/procfs/procfs_vnops.c
@@ -36,7 +36,7 @@
  *
  *	@(#)procfs_vnops.c	8.18 (Berkeley) 5/21/95
  *
- *	$Id: procfs_vnops.c,v 1.42 1997/11/07 08:53:15 phk Exp $
+ *	$Id: procfs_vnops.c,v 1.43 1997/12/05 19:55:47 bde Exp $
  */
 
 /*
@@ -56,6 +56,7 @@
 #include <sys/dirent.h>
 #include <machine/reg.h>
 #include <miscfs/procfs/procfs.h>
+#include <sys/pioctl.h>
 
 static int	procfs_abortop __P((struct vop_abortop_args *));
 static int	procfs_access __P((struct vop_access_args *));
@@ -64,6 +65,7 @@ static int	procfs_bmap __P((struct vop_bmap_args *));
 static int	procfs_close __P((struct vop_close_args *));
 static int	procfs_getattr __P((struct vop_getattr_args *));
 static int	procfs_inactive __P((struct vop_inactive_args *));
+static int	procfs_ioctl __P((struct vop_ioctl_args *));
 static int	procfs_lookup __P((struct vop_lookup_args *));
 static int	procfs_open __P((struct vop_open_args *));
 static int	procfs_print __P((struct vop_print_args *));
@@ -185,6 +187,79 @@ procfs_close(ap)
 }
 
 /*
+ * do an ioctl operation on a pfsnode (vp).
+ * (vp) is not locked on entry or exit.
+ */
+static int
+procfs_ioctl(ap)
+	struct vop_ioctl_args *ap;
+{
+	struct pfsnode *pfs = VTOPFS(ap->a_vp);
+	struct proc *procp;
+	int error;
+	int signo;
+	struct procfs_status *psp;
+
+	procp = pfind(pfs->pfs_pid);
+	if (procp == NULL) {
+		return ENOTTY;
+	}
+
+	switch (ap->a_command) {
+	case PIOCBIS:
+	  procp->p_stops |= *(unsigned int*)ap->a_data;
+	  break;
+	case PIOCBIC:
+	  procp->p_stops &= ~*(unsigned int*)ap->a_data;
+	  break;
+	case PIOCSFL:
+	  procp->p_pfsflags = (unsigned char)*(unsigned int*)ap->a_data;
+	  *(unsigned int*)ap->a_data = procp->p_stops;
+	  break;
+	case PIOCSTATUS:
+	  psp = (struct procfs_status *)ap->a_data;
+	  psp->state = (procp->p_step == 0);
+	  psp->flags = procp->p_pfsflags;
+	  psp->events = procp->p_stops;
+	  if (procp->p_step) {
+	    psp->why = procp->p_stype;
+	    psp->val = procp->p_xstat;
+	  } else {
+	    psp->why = psp->val = 0;	/* Not defined values */
+	  }
+	  break;
+	case PIOCWAIT:
+	  psp = (struct procfs_status *)ap->a_data;
+	  if (procp->p_step == 0) {
+	    error = tsleep(&procp->p_stype, PWAIT | PCATCH, "piocwait", 0);
+	    if (error)
+	      return error;
+	  }
+	  psp->state = 1;	/* It stopped */
+	  psp->flags = procp->p_pfsflags;
+	  psp->events = procp->p_stops;
+	  psp->why = procp->p_stype;	/* why it stopped */
+	  psp->val = procp->p_xstat;	/* any extra info */
+	  break;
+	case PIOCCONT:	/* Restart a proc */
+	  if (procp->p_step == 0)
+	    return EINVAL;	/* Can only start a stopped process */
+	  if (ap->a_data && (signo = *(int*)ap->a_data)) {
+	    if (signo >= NSIG || signo <= 0)
+	      return EINVAL;
+	    if (error = psignal(procp, signo))
+	      return error;
+	  }
+	  procp->p_step = 0;
+	  wakeup(&procp->p_step);
+	  break;
+	default:
+	  return (ENOTTY);
+	}
+	return 0;
+}
+
+/*
  * do block mapping for pfsnode (vp).
  * since we don't use the buffer cache
  * for procfs this function should never
@@ -909,6 +984,7 @@ static struct vnodeopv_entry_desc procfs_vnodeop_entries[] = {
 	{ &vop_setattr_desc,		(vop_t *) procfs_setattr },
 	{ &vop_symlink_desc,		(vop_t *) procfs_badop },
 	{ &vop_write_desc,		(vop_t *) procfs_rw },
+	{ &vop_ioctl_desc,		(vop_t *) procfs_ioctl },
 	{ NULL, NULL }
 };
 static struct vnodeopv_desc procfs_vnodeop_opv_desc =
diff --git a/sys/sys/pioctl.h b/sys/sys/pioctl.h
new file mode 100644
index 0000000..bc264e9
--- /dev/null
+++ b/sys/sys/pioctl.h
@@ -0,0 +1,36 @@
+/*
+ * procfs ioctl definitions.
+ *
+ * $Id$
+ */
+
+#ifndef _SYS_PIOCTL_H
+# define _SYS_PIOCTL_H
+
+# include <sys/ioccom.h>
+
+struct procfs_status {
+	int	state;	/* Running, stopped, something else? */
+	int	flags;	/* Any flags */
+	unsigned long	events;	/* Events to stop on */
+	int	why;	/* What event, if any, proc stopped on */
+	unsigned long	val;	/* Any extra data */
+};
+
+# define	PIOCBIS	_IOW('p', 1, unsigned int)	/* Set event flag */
+# define	PIOCBIC	_IOW('p', 2, unsigned int)	/* Clear event flag */
+# define	PIOCSFL	_IOR('p', 3, unsigned int)	/* Set flags */
+			/* wait for proc to stop */
+# define	PIOCWAIT	_IOR('p', 4, struct procfs_status)
+# define	PIOCCONT	_IOW('p', 5, int)	/* Continue a process */
+			/* Get proc status */
+# define	PIOCSTATUS	_IOW('p', 6, struct procfs_status)
+
+# define S_EXEC	0x00000001	/* stop-on-exec */
+# define	S_SIG	0x00000002	/* stop-on-signal */
+# define	S_SCE	0x00000004	/* stop on syscall entry */
+# define	S_SCX	0x00000008	/* stop on syscall exit */
+# define	S_CORE	0x00000010	/* stop on coredump */
+# define	S_EXIT	0x00000020	/* stop on exit */
+
+#endif 
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 201cb3d..2dc5c30 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)proc.h	8.15 (Berkeley) 5/19/95
- * $Id: proc.h,v 1.48 1997/11/24 15:15:20 bde Exp $
+ * $Id: proc.h,v 1.49 1997/11/25 07:07:48 julian Exp $
  */
 
 #ifndef _SYS_PROC_H_
@@ -151,6 +151,11 @@ struct	proc {
 
 	short	p_locks;		/* DEBUG: lockmgr count of held locks */
 	short	p_simple_locks;		/* DEBUG: count of held simple locks */
+	unsigned int	p_stops;	/* procfs event bitmask */
+	unsigned int	p_stype;	/* procfs stop event type */
+	char	p_step;			/* procfs stop *once* flag */
+	unsigned char	p_pfsflags;	/* procfs flags */
+	char	p_pad3[2];		/* padding for alignment */
 	register_t p_retval[2];		/* syscall aux returns */
 
 /* End area that is zeroed on creation. */
@@ -270,6 +275,10 @@ MALLOC_DECLARE(M_SUBPROC);
 		FREE(s, M_SESSION);					\
 }
 
+extern void stopevent(struct proc*, unsigned int, unsigned int);
+#define	STOPEVENT(p,e,v)	do { \
+	if ((p)->p_stops & (e)) stopevent(p,e,v); } while (0)
+
 /* hold process U-area in memory, normally for ptrace/procfs work */
 #define PHOLD(p) {							\
 	if ((p)->p_lock++ == 0 && ((p)->p_flag & P_INMEM) == 0)	\