1512_init_kill_all.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Vincent Strubel <clipos@ssi.gouv.fr>
Date: Mon, 1 Jan 2007 00:00:00 +0200
Subject: [PATCH 12/32] clip: vserver: Allow init to kill every process on the
 system

Allows init to kill every process on the system, regardless of vserver
context boundaries.

When pid 1 is killed the signal is broadcasted to all the processes of
the machine regardless of their xid.

Patch: 1512_init_kill_all.patch
---
 kernel/signal.c | 52 +++++++++++++++++++++++++++++++++++--------------
 1 file changed, 37 insertions(+), 15 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 1d95228b7c4dd..5b3ce00c18c07 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1191,6 +1191,42 @@ int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p,
 	return ret;
 }
 
+
+/* helper */
+static inline int
+_kill_all(int sig, struct siginfo *info)
+{
+	struct task_struct *p;
+	int retval = 0, count = 0;
+
+	read_lock(&tasklist_lock);
+	if (current->pid == 1) {
+		for_each_process(p) {
+			if (p->pid > 1) {
+				int err = group_send_sig_info(sig, info, p);
+				++count;
+				if (err != -EPERM)
+					retval = err;
+			}
+		}
+	} else {
+		for_each_process(p) {
+			if (vx_check(vx_task_xid(p), VS_ADMIN_P|VS_IDENT) &&
+					task_pid_vnr(p) > 1 &&
+					!same_thread_group(p, current) &&
+					!vx_current_initpid(p->pid)) {
+				int err = group_send_sig_info(sig, info, p);
+				++count;
+				if (err != -EPERM)
+					retval = err;
+			}
+		}
+	}
+	read_unlock(&tasklist_lock);
+	return count ? retval : -ESRCH;
+}
+
+
 /*
  * Force a signal that the process can't ignore: if necessary
  * we unblock the signal and change any SIG_IGN to SIG_DFL.
@@ -1452,21 +1488,7 @@ static int kill_something_info(int sig, struct siginfo *info, pid_t pid)
 		ret = __kill_pgrp_info(sig, info,
 				pid ? find_vpid(-pid) : task_pgrp(current));
 	} else {
-		int retval = 0, count = 0;
-		struct task_struct * p;
-
-		for_each_process(p) {
-			if (vx_check(vx_task_xid(p), VS_ADMIN|VS_IDENT) &&
-				task_pid_vnr(p) > 1 &&
-				!same_thread_group(p, current) &&
-				!vx_current_initpid(p->pid)) {
-				int err = group_send_sig_info(sig, info, p);
-				++count;
-				if (err != -EPERM)
-					retval = err;
-			}
-		}
-		ret = count ? retval : -ESRCH;
+		ret = _kill_all(sig, info);
 	}
 	read_unlock(&tasklist_lock);
 
-- 
2.17.0