-----Original Message----- From: kernelnewbies-bounces@kernelnewbies.org [mailto:kernelnewbies- bounces@kernelnewbies.org] On Behalf Of limp Sent: Wednesday, June 08, 2011 3:24 PM To: kernelnewbies@kernelnewbies.org Cc: 'Daniel Baluta' Subject: RE: Linux module for causing a system hard lock-up
Hello,
Could anyone please let me know how can I achieve this?
Is hard lockup detector enabled in your system? Could you post your .config.
Hi there,
At the moment I haven't enabled a hard lockup detector (I guess you're talking about NMI watchdog, right?) but I am just trying to hard lockup Linux using a kernel module. I was expecting the posted module to do that but apparently it doesn't (Linux still works great after loading it).
Thanks,
John K.
Looking at your original code, I would expect it to lock up a single processor system but not an SMP system. On SMP spinlock_irq_save() will disable interrupts on the local CPU, but they are still enabled on the others. You might want to try replacing the calls to spinlock_irq_save() with calls to cli(), which if I am not mistaken will disable interrupts on all CPUs. Something like this perhaps: int init_module(void) { cli(); return 0; } Or perhaps this: int init_module(void) { cli(); while(1); return 0; }