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-rw-r--r--include/linux/kgdb.h2
-rw-r--r--kernel/debug/debug_core.c31
-rw-r--r--kernel/panic.c8
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