kdb: Avoid using dbg_io_ops until it is initialized

Tim Bird · jwessel · commit b8adde8ddec9 · 2012-03-22T15:07:16.000-05:00
This fixes a bug with setting a breakpoint during kdb initialization
(from kdb_cmds).  Any call to kdb_printf() before the initialization
of the kgdboc serial console driver (which happens much later during
bootup than kdb_init), results in kernel panic due to the use of
dbg_io_ops before it is initialized.

Signed-off-by: Tim Bird &lt;tim.bird@am.sony.com&gt;
Signed-off-by: Jason Wessel &lt;jason.wessel@windriver.com&gt;
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
@@ -689,7 +689,7 @@ int vkdb_printf(const char *fmt, va_list ap)
 	if (!dbg_kdb_mode && kgdb_connected) {
 		gdbstub_msg_write(kdb_buffer, retlen);
 	} else {
-		if (!dbg_io_ops->is_console) {
+		if (dbg_io_ops && !dbg_io_ops->is_console) {
 			len = strlen(kdb_buffer);
 			cp = kdb_buffer;
 			while (len--) {
