Commit f30fed10 authored by Jason Wessel's avatar Jason Wessel
Browse files

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: default avatarJason Wessel <jason.wessel@windriver.com>
parent a0d271cb

kernel/debug/debug_core.c

+18 −0
Original line number Diff line number Diff line
@@ -688,6 +688,22 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) 
	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 @@ static void kgdb_register_callbacks(void) 
		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 @@ static void kgdb_unregister_callbacks(void) 
	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();