From f30fed10c440a25937e509860fa207399b26efe5 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Fri, 12 Oct 2012 06:37:33 -0500 Subject: 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 --- kernel/debug/debug_core.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'kernel/debug/debug_core.c') diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 0557f24c6bca..8bfa373cd5fd 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -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(); -- cgit v1.2.3