diff options
| -rw-r--r-- | include/linux/kgdb.h | 2 | ||||
| -rw-r--r-- | kernel/debug/debug_core.c | 31 | ||||
| -rw-r--r-- | kernel/panic.c | 8 |
3 files changed, 21 insertions, 20 deletions
diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index fbf144aaa749..b072aeb1fd78 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -326,8 +326,10 @@ extern atomic_t kgdb_active; (raw_smp_processor_id() == atomic_read(&kgdb_active)) extern bool dbg_is_early; extern void __init dbg_late_init(void); +extern void kgdb_panic(const char *msg); #else /* ! CONFIG_KGDB */ #define in_dbg_master() (0) #define dbg_late_init() +static inline void kgdb_panic(const char *msg) {} #endif /* ! CONFIG_KGDB */ #endif /* _KGDB_H_ */ diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 10f1187b3907..f76d6f77dd5e 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -893,30 +893,25 @@ static struct sysrq_key_op sysrq_dbg_op = { }; #endif -static int kgdb_panic_event(struct notifier_block *self, - unsigned long val, - void *data) +void kgdb_panic(const char *msg) { + if (!kgdb_io_module_registered) + return; + /* - * Avoid entering the debugger if we were triggered due to a panic - * We don't want to get stuck waiting for input from user in such case. - * panic_timeout indicates the system should automatically + * We don't want to get stuck waiting for input from user if + * "panic_timeout" indicates the system should automatically * reboot on panic. */ if (panic_timeout) - return NOTIFY_DONE; + return; if (dbg_kdb_mode) - kdb_printf("PANIC: %s\n", (char *)data); + kdb_printf("PANIC: %s\n", msg); + kgdb_breakpoint(); - return NOTIFY_DONE; } -static struct notifier_block kgdb_panic_event_nb = { - .notifier_call = kgdb_panic_event, - .priority = INT_MAX, -}; - void __weak kgdb_arch_late(void) { } @@ -965,8 +960,6 @@ static void kgdb_register_callbacks(void) 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); #ifdef CONFIG_MAGIC_SYSRQ register_sysrq_key('g', &sysrq_dbg_op); #endif @@ -980,16 +973,14 @@ static void kgdb_register_callbacks(void) static void kgdb_unregister_callbacks(void) { /* - * When this routine is called KGDB should unregister from the - * panic handler and clean up, making sure it is not handling any + * When this routine is called KGDB should unregister from + * handlers and clean up, making sure it is not handling any * break exceptions at the time. */ 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(); #ifdef CONFIG_MAGIC_SYSRQ unregister_sysrq_key('g', &sysrq_dbg_op); diff --git a/kernel/panic.c b/kernel/panic.c index 057540b6eee9..d1ece4c363b9 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -12,6 +12,7 @@ #include <linux/debug_locks.h> #include <linux/sched/debug.h> #include <linux/interrupt.h> +#include <linux/kgdb.h> #include <linux/kmsg_dump.h> #include <linux/kallsyms.h> #include <linux/notifier.h> @@ -220,6 +221,13 @@ void panic(const char *fmt, ...) #endif /* + * If kgdb is enabled, give it a chance to run before we stop all + * the other CPUs or else we won't be able to debug processes left + * running on them. + */ + kgdb_panic(buf); + + /* * If we have crashed and we have a crash kernel loaded let it handle * everything else. * If we want to run this after calling panic_notifiers, pass |