kdb: Fix smatch warning on dbg_io_ops->is_console

jwessel · jwessel · commit 78724b8ef83f · 2012-03-29T17:41:23.000-05:00
The Smatch tool warned that the change from commit b8adde8 (kdb: Avoid using dbg_io_ops until it is initialized) should add another null check later in the kdb_printf(). It is worth noting that the second use of dbg_io_ops->is_console is protected by the KDB_PAGER state variable which would only get set when kdb is fully active and initialized. If we ever encounter changes or defects in the KDB_PAGER state we do not want to crash the kernel in a kdb_printf/printk. CC: Tim Bird <tim.bird@am.sony.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
@@ -743,7 +743,7 @@ int vkdb_printf(const char *fmt, va_list ap)
 		kdb_input_flush();
 		c = console_drivers;
 
-		if (!dbg_io_ops->is_console) {
+		if (dbg_io_ops && !dbg_io_ops->is_console) {
 			len = strlen(moreprompt);
 			cp = moreprompt;
 			while (len--) {
