tree b04b36aa2678527e951a7e3d7262926149ac2228
parent aa7e3a5e8b63628c7fc131effc163ade08ced41b
author Jose Abreu <Jose.Abreu@synopsys.com> 1504281623 +0100
committer Vineet Gupta <vgupta@synopsys.com> 1504290545 -0700

ARC: Re-enable MMU upon Machine Check exception

I recently came upon a scenario where I would get a double fault
machine check exception tiriggered by a kernel module.
However the ensuing crash stacktrace (ksym lookup) was not working
correctly.

Turns out that machine check auto-disables MMU while modules are allocated
in kernel vaddr spapce.

This patch re-enables the MMU before start printing the stacktrace
making stacktracing of modules work upon a fatal exception.

Cc: stable@kernel.org
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Reviewed-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: moved code into low level handler to avoid in 2 places]