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

[Steven Rostedt]

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