From 7fff4beb311dfab4f18ff2cd64f78ec89296a39a Mon Sep 17 00:00:00 2001 From: Anithra P Janakiraman Date: Mon, 28 Mar 2011 14:29:19 -0700 Subject: watchdog: softdog.c: enhancement to optionally invoke panic instead of reboot on timer expiry This is needed for determining the reason for failure when a softdog timeout occurs. We use softdog to watch for critical application failures and at the minimum a snapshot of the system would help to determine the cause. In such a scenario the application could fail but there isn't a softlockup as such, hence the detect softlockup feature does not help. The patch adds a module parameter soft_panic which when set to 1 causes softdog to invoke panic instead of reboot when the softdog timer expires. By invoking panic we execute kdump if it is configured and the vmcore generated by kdump should provide atleast a minimal idea of the reason for failure. Based on an original patch by Ken Sugawara Signed-off-by: Anithra P J Reviewed-by: WANG Cong Acked-by: Alan Cox Signed-off-by: Wim Van Sebroeck Signed-off-by: Andrew Morton --- drivers/watchdog/softdog.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'drivers/watchdog') diff --git a/drivers/watchdog/softdog.c b/drivers/watchdog/softdog.c index 100b114e3c3c..bf16ffb4d21e 100644 --- a/drivers/watchdog/softdog.c +++ b/drivers/watchdog/softdog.c @@ -48,6 +48,7 @@ #include #include #include +#include #define PFX "SoftDog: " @@ -75,6 +76,11 @@ MODULE_PARM_DESC(soft_noboot, "Softdog action, set to 1 to ignore reboots, 0 to reboot " "(default depends on ONLY_TESTING)"); +static int soft_panic; +module_param(soft_panic, int, 0); +MODULE_PARM_DESC(soft_panic, + "Softdog action, set to 1 to panic, 0 to reboot (default=0)"); + /* * Our timer */ @@ -98,7 +104,10 @@ static void watchdog_fire(unsigned long data) if (soft_noboot) printk(KERN_CRIT PFX "Triggered - Reboot ignored.\n"); - else { + else if (soft_panic) { + printk(KERN_CRIT PFX "Initiating panic.\n"); + panic("Software Watchdog Timer expired."); + } else { printk(KERN_CRIT PFX "Initiating system reboot.\n"); emergency_restart(); printk(KERN_CRIT PFX "Reboot didn't ?????\n"); @@ -267,7 +276,8 @@ static struct notifier_block softdog_notifier = { }; static char banner[] __initdata = KERN_INFO "Software Watchdog Timer: 0.07 " - "initialized. soft_noboot=%d soft_margin=%d sec (nowayout= %d)\n"; + "initialized. soft_noboot=%d soft_margin=%d sec soft_panic=%d " + "(nowayout= %d)\n"; static int __init watchdog_init(void) { @@ -298,7 +308,7 @@ static int __init watchdog_init(void) return ret; } - printk(banner, soft_noboot, soft_margin, nowayout); + printk(banner, soft_noboot, soft_margin, soft_panic, nowayout); return 0; } -- cgit v1.2.3-59-g8ed1b