Subject: Re: [PATCH] rtas: Validate rtas entry before calling enter_rtas

From: Vasant Hegde <[email-masked]>
Date: Sat, 17 Oct 2015 10:04:00 +0530

On 10/16/2015 11:49 PM, Denis Kirjanov wrote:
> On 10/16/15, Vasant Hegde <[email-masked]> wrote:
>> On 10/16/2015 04:02 PM, Denis Kirjanov wrote:
>>> On 10/16/15, Vasant Hegde <[email-masked]> wrote:
>>>> Currently we do not validate rtas entry before calling enter_rtas().
>>>> This
>>>> is resulting in a kernel oops (see below) when user space calls rtas
>>>> system
>>>> call on PowerNV platform. We hit below oops when we ran trinity (system
>>>> call
>>>> fuzzer) on PowerNV. This patch adds code to validate rtas entry before
>>>> making
>>>> enter_rtas() call.
>>>
>>> Hi,
>>> have you figured out why we have null entry?
>>
>> Denis,

Denis,

>>
>> Yes... On PowerNV platform we don't have RTAS.. Hence it's not initialized.
> But why do we have CONFIG_PPC_RTAS on OPAL machines then?

Sorry. I should have elaborated little bit..

Today we use single config to build kernel for both PowerNV and PAPR guest. So
that same ISO can be used in different environment (PAPR LPAR, PowerNV host,
guest). I believe most distro also following this method. Hence we need this
validation.

-Vasant