patch-2.3.23 linux/kernel/exit.c

• Lines: 62
• Date: Mon Oct 18 11:35:32 1999
• Orig file: v2.3.22/linux/kernel/exit.c
• Orig date: Thu Aug 26 13:05:42 1999

diff -u --recursive --new-file v2.3.22/linux/kernel/exit.c linux/kernel/exit.c
@@ -135,7 +135,9 @@
 	read_lock(&tasklist_lock);
 	for_each_task(p) {
 		if (p->p_opptr == father) {
+			/* We dont want people slaying init */
 			p->exit_signal = SIGCHLD;
+			p->self_exec_id++;
 			p->p_opptr = child_reaper; /* init */
 			if (p->pdeath_signal) send_sig(p->pdeath_signal, p, 0);
 		}
@@ -288,7 +290,7 @@
  */
 static void exit_notify(void)
 {
-	struct task_struct * p;
+	struct task_struct * p, *t;
 
 	forget_original_parent(current);
 	/*
@@ -300,15 +302,39 @@
 	 * and we were the only connection outside, so our pgrp
 	 * is about to become orphaned.
 	 */
-	if ((current->p_pptr->pgrp != current->pgrp) &&
-	    (current->p_pptr->session == current->session) &&
+	 
+	t = current->p_pptr;
+	
+	if ((t->pgrp != current->pgrp) &&
+	    (t->session == current->session) &&
 	    will_become_orphaned_pgrp(current->pgrp, current) &&
 	    has_stopped_jobs(current->pgrp)) {
 		kill_pg(current->pgrp,SIGHUP,1);
 		kill_pg(current->pgrp,SIGCONT,1);
 	}
 
-	/* Let father know we died */
+	/* Let father know we died 
+	 *
+	 * Thread signals are configurable, but you aren't going to use
+	 * that to send signals to arbitary processes. 
+	 * That stops right now.
+	 *
+	 * If the parent exec id doesn't match the exec id we saved
+	 * when we started then we know the parent has changed security
+	 * domain.
+	 *
+	 * If our self_exec id doesn't match our parent_exec_id then
+	 * we have changed execution domain as these two values started
+	 * the same after a fork.
+	 *	
+	 */
+	
+	if(current->exit_signal != SIGCHLD &&
+	    ( current->parent_exec_id != t->self_exec_id  ||
+	      current->self_exec_id != current->parent_exec_id) 
+	    && !capable(CAP_KILL))
+		current->exit_signal = SIGCHLD;
+
 	notify_parent(current, current->exit_signal);
 
 	/*