PowerPC processor has a big family -- Some of them can support hardware data break point register -- and this can capture it.

Several days before, I tried to dump the instructions around fault pc and it worked.

I found NO kernel text corruption happened because all the instructions around fault pc (and at fault pc) looks good. All the instructions can be disassembled correctly.

I'm suspecting the instruction cache has been corrupted. It seems no direct way supplied to dump instruction cache.