[PATCH 4/5] vt: Update spawnpid to use a task_ref.

[ebiederm@xmission.com (Eric W. Biederman)]

This is a classic example of a random kernel subsystem
holding a pid for purposes of signalling it later.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>


---

 drivers/char/keyboard.c |    8 ++++----
 drivers/char/vt_ioctl.c |    5 +++--
 2 files changed, 7 insertions(+), 6 deletions(-)

7ed8301463a49ad03f8c9de2bbf8c41a5d9843ea
diff --git a/drivers/char/keyboard.c b/drivers/char/keyboard.c
index 8b603b2..4e1f2e0 100644
--- a/drivers/char/keyboard.c
+++ b/drivers/char/keyboard.c
@@ -109,7 +109,8 @@ struct kbd_struct kbd_table[MAX_NR_CONSO
 static struct kbd_struct *kbd = kbd_table;
 static struct kbd_struct kbd0;
 
-int spawnpid, spawnsig;
+TASK_REF(spawnpid);
+int spawnsig;
 
 /*
  * Variables exported for vt.c
@@ -567,9 +568,8 @@ static void fn_compose(struct vc_data *v
 
 static void fn_spawn_con(struct vc_data *vc, struct pt_regs *regs)
 {
-	if (spawnpid)
-		if (kill_proc(spawnpid, spawnsig, 1))
-			spawnpid = 0;
+	if (kill_tref(spawnpid, spawnsig, 1))
+		tref_clear(&spawnpid);
 }
 
 static void fn_SAK(struct vc_data *vc, struct pt_regs *regs)
diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c
index 24011e7..f8a527b 100644
--- a/drivers/char/vt_ioctl.c
+++ b/drivers/char/vt_ioctl.c
@@ -646,12 +646,13 @@ int vt_ioctl(struct tty_struct *tty, str
 	 */
 	case KDSIGACCEPT:
 	{
-		extern int spawnpid, spawnsig;
+		extern struct task_ref *spawnpid;
+		extern int spawnsig;
 		if (!perm || !capable(CAP_KILL))
 		  return -EPERM;
 		if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
 		  return -EINVAL;
-		spawnpid = current->pid;
+		tref_set(&spawnpid, tref_get_by_task(current, PIDTYPE_PID));
 		spawnsig = arg;
 		return 0;
 	}
-- 
1.1.5.g3480