Re: kvm: unable to handle kernel NULL pointer dereference

From: Chris Wright
Date: Thu Jun 05 2008 - 14:35:53 EST


* Tobias Diedrich (ranma+kernel@xxxxxxxxxxxx) wrote:
> PM: Creating hibernation image:
> PM: Need to copy 126181 pages
> PM: Normal pages needed: 126181 + 1024 + 38, available pages: 397721
> x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106
> svm_cpu_init: svm_data is NULL on 0

Yeah, this is broken. What happens is:

suspend:
hardware_disable
svm_hardware_disable
kfree(svm_data)
per_cpu(svm_data) = NULL

resume:
hardware_enable
svm_hardware_enable
if(!svm_data) printk("svm_cpu_init: svm_data is NULL on 0")

at this point it is broken.

Same would happen on an SMP box by simply doing offline/online of a CPU.
This is definitely busted, looking into a patch.

thanks,
-chris
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