Log crash to nvsram

From: Subin C. P.
Date: Fri Oct 20 2023 - 07:02:39 EST


Hi,

Apologies if I’m intruding. I got this mail id while reading Documentation/oops-tracing.txt.

I’m getting below kernel crash. This is logged to serial console. I wanted to write this to a non volatile RAM. I’ve registered to panic _notifier_list, die_notifier _list, cpu_notifier _list, memory _notifier _list, oom_notifier _list. But my callback is not getting called during this crash in order to write this to the nvsram.
Is this log happening outside kernel? Can’t we get a notification when this crash occurs?

*******************************************************************************************
cpu_4 received a bus/cache error(warning)
*******************************************************************************************
CPU (XLP specific) registers dump: Node=0
COP2: TxMsgStatus = 0x00000000, MsgStatus1 = 0x0f0f0000
ICU: log0 = 0x00000000, log1 = 0x00000000, log2 = 0x00000000
LSU: log0 = 0x00000000, log1 = 0x0000000000000000
SCU: log0 = 0x00000000, log1 = 0x00000000, log2 = 0x00000000
TCU: reg0 = 0x00000000, reg1 = 0x00000000, reg2 = 0x00000000
NBU: reg0 = 0x00000000, reg1 = 0x00000000, reg2 = 0x00000000
DRAM_A: reg1 = 0x00000000, reg2 = 0x00000000
DRAM_B: reg1 = 0x00000000, reg2 = 0x00000000
DRAM_C: reg1 = 0x00000000, reg2 = 0x00000000
DRAM_D: reg1 = 0x00000000, reg2 = 0x00000000

CPU: epc = 0x105bc310, errorepc = 0xffffffffc1024270, cacheerr = 0x00000000
*******************************************************************************************
Unknown Cache error in exception handler!
Can not handle bus/cache error - Halting cpu

Thanks,
Subin.