Re: [PATCH v4 00/10] klp-convert livepatch build tooling

From: Joe Lawrence
Date: Tue Jun 25 2019 - 09:24:32 EST


On 6/25/19 7:36 AM, Miroslav Benes wrote:

> [ ... snip ... ]
>
So I made a couple of experiments and found that GCC is somehow involved.
If klp-convert (from scripts/livepatch/) is compiled with our GCC 4.8.5
from SLE12, the output is incorrect. If I compile it with GCC 7.4.0 from
openSUSE Leap 15.1, the output is correct.

If I revert commit d59cadc0a8f8 ("[squash] klp-convert: make
convert_rela() list-safe") (from Joe's expanded github tree), the problem
disappears.

I haven't spotted any problem in the code and I cannot explain a
dependency on GCC version. Any ideas?


Thanks for revisiting and debugging this. Narrowing it down to my "fix" to convert_rela() should be helpful.

In my case, I was probably testing with RHEL-8, which has gcc 8.2 vs RHEL-7 which has gcc 4.8. I'll have to make sure to try with a few different versions for the next round.

-- Joe