Re: [PATCH 0/3] x86/paravirt: Fix baremetal paravirt MSR ops

From: Arjan van de Ven
Date: Thu Sep 17 2015 - 11:31:29 EST


On 9/17/2015 8:29 AM, Paolo Bonzini wrote:


On 17/09/2015 17:27, Arjan van de Ven wrote:

( We should double check that rdmsr()/wrmsr() results are never left
uninitialized, but are set to zero or so, for cases where the
return code is not
checked. )

It sure looks like native_read_msr_safe doesn't clear the output if
the rdmsr fails.

I'd suggest to return some poison not just 0...

What about 0 + WARN?

why 0?

0xdeadbeef or any other pattern (even 0x3636363636) makes more sense (of course also WARN... but most folks don't read dmesg for WARNs)

(it's the same thing we do for list or slab poison stuff)

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