2 files changed, 143 insertions, 2 deletions

diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index 0746e5876b230..d7e42026b83e0 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 1.34 1996/07/27 03:23:42 dyson Exp $
+ * $Id: kern_exit.c,v 1.35 1996/07/30 03:08:37 dyson Exp $
  */
 
 #include "opt_ktrace.h"
@@ -81,6 +81,16 @@
 static int wait1 __P((struct proc *, struct wait_args *, int [], int));
 
 /*
+ * callout list for things to do at exit time
+ */
+typedef struct exit_list_element {
+	struct exit_list_element *next;
+	exitlist_fn function;
+} *ele_p;
+
+static ele_p exit_list;
+
+/*
  * exit --
  *	Death of process.
  */
@@ -109,6 +119,7 @@ exit1(p, rv)
 {
 	register struct proc *q, *nq;
 	register struct vmspace *vm;
+	ele_p ep = exit_list;
 
 	if (p->p_pid == 1) {
 		printf("init died (signal %d, exit %d)\n",
@@ -118,6 +129,16 @@ exit1(p, rv)
 #ifdef PGINPROF
 	vmsizmon();
 #endif
+	/* 
+	 * Check if any LKMs need anything done at process exit
+	 * e.g. SYSV IPC stuff
+	 * XXX what if one of these generates an error?
+	 */
+	while(ep) {
+		(*ep->function)(p);
+		ep = ep->next;
+	}
+
 	if (p->p_flag & P_PROFIL)
 		stopprofclock(p);
 	MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
@@ -473,3 +494,52 @@ proc_reparent(child, parent)
 	LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
 	child->p_pptr = parent;
 }
+
+/*********************************************************
+ * general routines to handle adding/deleting items on the
+ * exit callout list
+ *****
+ * Take the arguments given and put them onto the exit callout list.
+ * However first make sure that it's not already there.
+ * returns 0 on success.
+ */
+int
+at_exit(exitlist_fn function)
+{
+	ele_p ep;
+	if(rm_at_exit(function)) {
+		printf("exit callout entry already present\n");
+	}
+	ep = malloc(sizeof(*ep),M_TEMP,M_NOWAIT);
+	if(!ep) return ENOMEM;
+	ep->next = exit_list;
+	ep->function = function;
+	exit_list = ep;
+	return 0;
+}
+/*
+ * Scan the exit callout list for the given items and remove them.
+ * Returns the number of items removed.
+ */
+int
+rm_at_exit(exitlist_fn function)
+{
+	ele_p *epp,ep;
+	int count = 0;
+
+	epp = &exit_list;
+	ep = *epp;
+	while(ep) {
+		if(ep->function == function) {
+			*epp = ep->next;
+			free(ep,M_TEMP);
+			count++;
+		} else {
+			epp = &ep->next;
+		}
+		ep = *epp;
+	}
+	return count;
+}
+
+
diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index 2ac184961db27..f6bb2840748b8 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)kern_fork.c	8.6 (Berkeley) 4/8/94
- * $Id: kern_fork.c,v 1.22 1996/06/12 05:07:30 gpalmer Exp $
+ * $Id: kern_fork.c,v 1.23 1996/07/31 09:26:34 davidg Exp $
  */
 
 #include "opt_ktrace.h"
@@ -64,6 +64,16 @@
 
 static int fork1 __P((struct proc *p, int flags, int *retval));
 
+/*
+ * callout list for things to do at fork time
+ */
+typedef struct fork_list_element {
+	struct fork_list_element *next;
+	forklist_fn function;
+} *fle_p;
+
+static fle_p fork_list;
+
 #ifndef _SYS_SYSPROTO_H_
 struct fork_args {
         int     dummy;
@@ -114,6 +124,7 @@ fork1(p1, flags, retval)
 	struct proc *newproc;
 	int count;
 	static int nextpid, pidchecked = 0;
+	fle_p ep = fork_list;
 
 	if ((flags & RFPROC) == 0)
 		return (EINVAL);
@@ -335,6 +346,16 @@ again:
 	}
 
 	/*
+	 * Both processes are set up, 
+	 * check if any LKMs want to adjust anything
+	 * What if they have an error? XXX
+	 */
+        while(ep) {
+                (*ep->function)(p1,p2,flags);
+                ep = ep->next;
+        }
+
+	/*
 	 * Make child runnable and add to run queue.
 	 */
 	(void) splhigh();
@@ -363,3 +384,53 @@ again:
 	retval[1] = 0;
 	return (0);
 }
+
+
+/*********************************************************
+ * general routines to handle adding/deleting items on the
+ * fork callout list
+ *****
+ * Take the arguments given and put them onto the fork callout list.
+ * However first make sure that it's not already there.
+ * returns 0 on success.
+ */
+int
+at_fork(forklist_fn function)
+{
+	fle_p ep;
+	if(rm_at_fork(function)) {
+		printf("fork callout entry already present\n");
+	}
+	ep = malloc(sizeof(*ep),M_TEMP,M_NOWAIT);
+	if(!ep) return ENOMEM;
+	ep->next = fork_list;
+	ep->function = function;
+	fork_list = ep;
+	return 0;
+}
+/*
+ * Scan the exit callout list for the given items and remove them.
+ * Returns the number of items removed.
+ */
+int
+rm_at_fork(forklist_fn function)
+{
+	fle_p *epp,ep;
+	int count = 0;
+
+	epp = &fork_list;
+	ep = *epp;
+	while(ep) {
+		if(ep->function == function) {
+			*epp = ep->next;
+			free(ep,M_TEMP);
+			count++;
+		} else {
+			epp = &ep->next;
+		}
+		ep = *epp;
+	}
+	return count;
+}
+
+