[PATCH] Clear TLS on execve

This trivial patch causes the TLS to be cleared on execve (code is in
flush_thread).  This is necessary to avoid ESRCH errors when
set_thread_area is asked to choose a free TLS entry after several nested
execve's.

The LDT also has a similar problem, but it is less serious because the
LDT code doesn't scan for free entries.  I'll probably send a patch to
fix this too, unless there is something important relying on this
behavior.

arch/i386/kernel/process.c

@@ -247,6 +247,7 @@ void flush_thread(void)
 	struct task_struct *tsk = current;
 
 	memset(tsk->thread.debugreg, 0, sizeof(unsigned long)*8);
+	memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));	
 	/*
 	 * Forget coprocessor state..
 	 */