A mechanism to allow debuggers to learn about starting/dying tasks.

Signed-Off-By: Jan Beulich <jbeulich@novell.com>

Index: 2.6.14-nlkd/include/linux/sched.h
===================================================================
--- 2.6.14-nlkd.orig/include/linux/sched.h	2005-11-09 10:40:17.000000000 +0100
+++ 2.6.14-nlkd/include/linux/sched.h	2005-11-04 16:19:34.000000000 +0100
@@ -34,6 +34,7 @@
 #include <linux/percpu.h>
 #include <linux/topology.h>
 #include <linux/seccomp.h>
+#include <linux/notifier.h>
 
 #include <linux/auxvec.h>	/* For AT_VECTOR_SIZE */
 
@@ -1109,6 +1110,11 @@ extern int do_execve(char *, char __user
 extern long do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int __user *, int __user *);
 task_t *fork_idle(int);
 
+#define TASK_NEW 1
+#define TASK_DELETE 2
+
+extern struct notifier_block *task_notifier_list;
+
 extern void set_task_comm(struct task_struct *tsk, char *from);
 extern void get_task_comm(char *to, struct task_struct *tsk);
 
Index: 2.6.14-nlkd/kernel/fork.c
===================================================================
--- 2.6.14-nlkd.orig/kernel/fork.c	2005-11-09 10:40:17.000000000 +0100
+++ 2.6.14-nlkd/kernel/fork.c	2005-11-04 16:19:34.000000000 +0100
@@ -64,6 +64,9 @@ DEFINE_PER_CPU(unsigned long, process_co
 
 EXPORT_SYMBOL(tasklist_lock);
 
+struct notifier_block *task_notifier_list = NULL;
+EXPORT_SYMBOL(task_notifier_list);
+
 int nr_processes(void)
 {
 	int cpu;
@@ -108,6 +111,8 @@ EXPORT_SYMBOL(free_task);
 
 void __put_task_struct(struct task_struct *tsk)
 {
+	notifier_call_chain(&task_notifier_list, TASK_DELETE, tsk);
+
 	WARN_ON(!(tsk->exit_state & (EXIT_DEAD | EXIT_ZOMBIE)));
 	WARN_ON(atomic_read(&tsk->usage));
 	WARN_ON(tsk == current);
@@ -1279,6 +1284,8 @@ long do_fork(unsigned long clone_flags,
 			set_tsk_thread_flag(p, TIF_SIGPENDING);
 		}
 
+		notifier_call_chain(&task_notifier_list, TASK_NEW, p);
+
 		if (!(clone_flags & CLONE_STOPPED))
 			wake_up_new_task(p, clone_flags);
 		else