[PATCH] Prevent reuse of active thread group id

[Dave McCracken]

The thread group id of a task is initially assigned the value of that 
task's pid, then is inherited for each child task created with 
CLONE_THREAD.  This patch makes sure that the thread group id is never 
re-used as another task's pid as long as there's an active task with that 
tgid.

Patch is below.

Dave McCracken

======================================================================
Dave McCracken          IBM Linux Base Kernel Team      1-512-838-3059
[e-mail]                                        T/L   678-3059

====================

--- linux-2.4.9/./kernel/fork.c	Tue Jul 17 20:23:28 2001
+++ linux-2.4.9-tgid/./kernel/fork.c	Mon Aug 20 10:28:22 2001
@@ -101,6 +101,7 @@
 		for_each_task(p) {
 			if(p->pid == last_pid	||
 			   p->pgrp == last_pid	||
+			   p->tgid == last_pid	||
 			   p->session == last_pid) {
 				if(++last_pid >= next_safe) {
 					if(last_pid & 0xffff8000)