kgdb: Add module event hooks
Allow gdb to auto load kernel modules when it is attached,
which makes it trivially easy to debug module init functions
or pre-set breakpoints in a kernel module that has not loaded yet.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 0557f24..8bfa373 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -688,6 +688,22 @@
return kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
}
+/*
+ * GDB places a breakpoint at this function to know dynamically
+ * loaded objects. It's not defined static so that only one instance with this
+ * name exists in the kernel.
+ */
+
+static int module_event(struct notifier_block *self, unsigned long val,
+ void *data)
+{
+ return 0;
+}
+
+static struct notifier_block dbg_module_load_nb = {
+ .notifier_call = module_event,
+};
+
int kgdb_nmicallback(int cpu, void *regs)
{
#ifdef CONFIG_SMP
@@ -816,6 +832,7 @@
kgdb_arch_init();
if (!dbg_is_early)
kgdb_arch_late();
+ register_module_notifier(&dbg_module_load_nb);
register_reboot_notifier(&dbg_reboot_notifier);
atomic_notifier_chain_register(&panic_notifier_list,
&kgdb_panic_event_nb);
@@ -839,6 +856,7 @@
if (kgdb_io_module_registered) {
kgdb_io_module_registered = 0;
unregister_reboot_notifier(&dbg_reboot_notifier);
+ unregister_module_notifier(&dbg_module_load_nb);
atomic_notifier_chain_unregister(&panic_notifier_list,
&kgdb_panic_event_nb);
kgdb_arch_exit();
