From: Nicholas Piggin <npiggin@gmail•com>
To: Ganesh Goudar <ganeshgr@linux•ibm.com>,
linuxppc-dev@lists•ozlabs.org, mpe@ellerman•id.au
Cc: aneesh.kumar@linux•ibm.com, mahesh@linux•vnet.ibm.com
Subject: Re: [PATCH] powerpc/mce: Avoid using addr_to_pfn in realmode
Date: Mon, 22 Jun 2020 12:16:11 +1000 [thread overview]
Message-ID: <1592791213.eqbgr0cksa.astroid@bobo.none> (raw)
In-Reply-To: <20200620124435.9900-1-ganeshgr@linux.ibm.com>
Excerpts from Ganesh Goudar's message of June 20, 2020 10:44 pm:
> When an UE or memory error exception is encountered the MCE handler
> tries to find the pfn using addr_to_pfn() which takes effective
> address as an argument, later pfn is used to poison the page where
> memory error occurred, recent rework in this area made addr_to_pfn
> to run in realmode, which can be fatal as it may try to access
> memory outside RMO region.
>
> To fix this move the use of addr_to_pfn to save_mce_event(), which
> runs in virtual mode.
I'd rather this be done in the pseries mce handler rather than
change bare metal, and leaving save_mce_event as purely recording the
event, decoding remains in its caller.
Radix guests also don't have an RMO, we could probably restrict that
pseries hack to hash. I want to get rid of it but it will take longer
to fix things properly.
Thanks,
Nick
prev parent reply other threads:[~2020-06-22 2:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-20 12:44 [PATCH] powerpc/mce: Avoid using addr_to_pfn in realmode Ganesh Goudar
2020-06-22 2:16 ` Nicholas Piggin [this message]
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