On 12/16/15, Jeff Merkey <linux....@gmail.com> wrote: > Setting the (trap flag | resume flag) inside of an nmi handler results > in a hard lockup while setting the resume flag works fine. > > The watchdog detector fails to detect the lockup. I am currently > examining the trap gate and interrupt gate setup on Linux and if > anyone has any ideas it would be nice to be able to debug and step > through the nmi handlers. I got breakpoints to work. I noticed > kgdb/kdb just punts here and refuses to allow someone to step inside > an nmi handler. > > There is no reason Linux should not allow this to work since windows > does and every other OS out there. I have seen this across some rex64 > sysret calls as well this lockup behavior. > > Anyone who is an intel expert with any clues would love some input if > you know about this problem. > > Jeff >
More info. Linux is getting a trap and it looks like the IDT is getting swapped when it gets it -- POW - Dead Linux. Damn ... Well, it will be long night and lots of builds ... Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
