Re: [PATCH] rseq/selftests: fix parametrized test with -fpie

[Shuah Khan]

On 09/27/2018 12:02 PM, Mathieu Desnoyers wrote:
> ----- On Sep 27, 2018, at 9:58 AM, Shuah Khan shuah.kh@xxxxxxxxxxx wrote:
> 
>> On 09/27/2018 07:22 AM, Steven Rostedt wrote:
>>> On Tue, 25 Sep 2018 13:39:36 -0400 (EDT)
>>> Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote:
>>>
>>>> ----- On Sep 18, 2018, at 9:53 AM, Mathieu Desnoyers
>>>> mathieu.desnoyers@xxxxxxxxxxxx wrote:
>>>>
>>>>> On x86-64, the parametrized selftest code for rseq crashes with a
>>>>> segmentation fault when compiled with -fpie. This happens when the
>>>>> param_test binary is loaded at an address beyond 32-bit on x86-64.
>>>>>
>>>>> The issue is caused by use of a 32-bit register to hold the address
>>>>> of the loop counter variable.
>>>>>
>>>>> Fix this by using a 64-bit register to calculate the address of the
>>>>> loop counter variables as an offset from rip.
>>>>
>>>> Should this fix go through tip or the selftests tree ?
>>>>
>>>
>>> I usually have changes like this pulled through Shuah's tree with an
>>> ack from the maintainer of the code that it tests.
>>>
>>> -- Steve
>>>
>>
>> Right that is what I prefer. I usually wait for an Ack. I can pull this
>> in.
> 
> I am maintainer of the code that it tests as well, so being both author
> of the selftest patch and giving an ack to it seems a bit silly. :) Other
> rseq co-maintainers could weight in though: Peter, Paul, and Boqun.
> 

I was commenting in general, not specific to this patch. No worries. I will
apply this right away.

I have been traveling the last couple of weeks and in the catch up mode still.

thanks,
-- Shuah


>>
>> --
>> Shuah Khan
>> Sr. Linux Kernel Developer
>> Open Source Innovation Group
>> Samsung Research America(Silicon Valley)
>> shuah.kh@xxxxxxxxxxx
> 


-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America(Silicon Valley)
shuah.kh@xxxxxxxxxxx