debug_core,kdb: fix crash when arch does not have single step

jwessel · jwessel · commit 3fa43aba08c5 · 2010-08-05T09:22:25.000-05:00
When an arch such as mips and microblaze does not implement either HW
or software single stepping the debug core should re-enter kdb.  The
kdb code will properly ignore the single step operation.  Attempting
to single step the kernel without software or hardware support causes
unpredictable kernel crashes.

Signed-off-by: Jason Wessel &lt;jason.wessel@windriver.com&gt;
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
@@ -605,6 +605,8 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs)
 		if (dbg_kdb_mode) {
 			kgdb_connected = 1;
 			error = kdb_stub(ks);
+			if (error == -1)
+				continue;
 			kgdb_connected = 0;
 		} else {
 			error = gdb_serial_stub(ks);
