kgdb,debug-core,gdbstub: Hook the reboot notifier for debugger detach
The gdbstub and kdb should get detached if the system is rebooting.
Calling gdbstub_exit() will set the proper debug core state and send a
message to any debugger that is connected to correctly detach.
An attached debugger will receive the exit code from
include/linux/reboot.h based on SYS_HALT, SYS_REBOOT, etc...
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 0d7c087..3c1ad4e 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -41,6 +41,7 @@
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/sysrq.h>
+#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/kgdb.h>
#include <linux/kdb.h>
@@ -784,6 +785,20 @@
kdb_init(KDB_INIT_FULL);
}
+static int
+dbg_notify_reboot(struct notifier_block *this, unsigned long code, void *x)
+{
+ if (!dbg_kdb_mode)
+ gdbstub_exit(code);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block dbg_reboot_notifier = {
+ .notifier_call = dbg_notify_reboot,
+ .next = NULL,
+ .priority = INT_MAX,
+};
+
static void kgdb_register_callbacks(void)
{
if (!kgdb_io_module_registered) {
@@ -791,6 +806,7 @@
kgdb_arch_init();
if (!dbg_is_early)
kgdb_arch_late();
+ register_reboot_notifier(&dbg_reboot_notifier);
atomic_notifier_chain_register(&panic_notifier_list,
&kgdb_panic_event_nb);
#ifdef CONFIG_MAGIC_SYSRQ
@@ -812,6 +828,7 @@
*/
if (kgdb_io_module_registered) {
kgdb_io_module_registered = 0;
+ unregister_reboot_notifier(&dbg_reboot_notifier);
atomic_notifier_chain_unregister(&panic_notifier_list,
&kgdb_panic_event_nb);
kgdb_arch_exit();
