[PATCH] 2.5.63 tsk->usage count.

[Martin Schwidefsky <schwidefsky@de.ibm.com>]

Hi Linus,
while debugging a memory leak with task structures on s390
I found something related to it. If copy_process fails for some
reason the task structure created with dup_task_struct has set
p->usage to 2 but only one put_task_struct is done in the error
cleanup code. The attached patch should take care of it.

blue skies,
  Martin.

diff -urN linux-2.5/kernel/fork.c linux-2.5-fork/kernel/fork.c
--- linux-2.5/kernel/fork.c	Thu Feb 27 11:25:56 2003
+++ linux-2.5-fork/kernel/fork.c	Thu Feb 27 10:11:42 2003
@@ -1034,6 +1034,8 @@
 	atomic_dec(&p->user->processes);
 	free_uid(p->user);
 bad_fork_free:
+	/* dup_task_struct sets p->usage to 2 */
+	atomic_dec(&p->usage);
 	put_task_struct(p);
 	goto fork_out;
 }