diff options
| author | Jason Wessel <jason.wessel@windriver.com> | 2012-03-20 00:35:55 (GMT) |
|---|---|---|
| committer | Jason Wessel <jason.wessel@windriver.com> | 2012-03-22 20:07:16 (GMT) |
| commit | bec4d62ead8096e433d624d9339893f50badd992 (patch) | |
| tree | fd48a6b49acaec668f8b9dfa18c9dedc56d8a0b7 /kernel/debug | |
| parent | 8f30d411767351656ea62c9e7612120f9b870b59 (diff) | |
| download | linux-fsl-qoriq-bec4d62ead8096e433d624d9339893f50badd992.tar.xz | |
kgdb,debug_core: add the ability to control the reboot notifier
Sometimes it is desirable to stop the kernel debugger before allowing
a system to reboot either with kdb or kgdb. This patch adds the
ability to turn the reboot notifier on and off or enter the debugger
and stop kernel execution before rebooting.
It is possible to change the setting after booting the kernel with the
following:
echo 1 > /sys/module/debug_core/parameters/kgdbreboot
It is also possible to change this setting using kdb / kgdb to
manipulate the variable directly.
Using KDB:
mm kgdbreboot 1
Using gdb:
set kgdbreboot=1
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Diffstat (limited to 'kernel/debug')
| -rw-r--r-- | kernel/debug/debug_core.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 3c1ad4e..3f88a45 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -76,6 +76,8 @@ static int exception_level; struct kgdb_io *dbg_io_ops; static DEFINE_SPINLOCK(kgdb_registration_lock); +/* Action for the reboot notifiter, a global allow kdb to change it */ +static int kgdbreboot; /* kgdb console driver is loaded */ static int kgdb_con_registered; /* determine if kgdb console output should be used */ @@ -97,6 +99,7 @@ static int __init opt_kgdb_con(char *str) early_param("kgdbcon", opt_kgdb_con); module_param(kgdb_use_con, int, 0644); +module_param(kgdbreboot, int, 0644); /* * Holds information about breakpoints in a kernel. These breakpoints are @@ -788,8 +791,21 @@ void __init dbg_late_init(void) static int dbg_notify_reboot(struct notifier_block *this, unsigned long code, void *x) { + /* + * Take the following action on reboot notify depending on value: + * 1 == Enter debugger + * 0 == [the default] detatch debug client + * -1 == Do nothing... and use this until the board resets + */ + switch (kgdbreboot) { + case 1: + kgdb_breakpoint(); + case -1: + goto done; + } if (!dbg_kdb_mode) gdbstub_exit(code); +done: return NOTIFY_DONE; } |