[PARISC] be more defensive in process.c::get_wchan

Kyle McMartin · Kyle McMartin · commit cc650a7a9f5e · 2007-05-30T02:36:00.000-04:00
While debugging, I noticed we don't check the task_struct arg passed to
get_wchan, whereas everyone else does.

Signed-off-by: Kyle McMartin &lt;kyle@parisc-linux.org&gt;
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
@@ -381,6 +381,10 @@ get_wchan(struct task_struct *p)
 	struct unwind_frame_info info;
 	unsigned long ip;
 	int count = 0;
+
+	if (!p || p == current || p->state == TASK_RUNNING)
+		return 0;
+
 	/*
 	 * These bracket the sleeping functions..
 	 */
