Re: [PATCH] github: Reduce ASLR entropy to be compatible with asan in llvm 14.

[Aaron Conole <aconole@redhat.com>]

Ilya Maximets <i.maximets@ovn.org> writes:

> Starting with image version 20240310.1.0, GitHub runners are using
> 32-bit entropy for ASLR:
>
>   $ sudo sysctl -a | grep vm.mmap.rnd
>   vm.mmap_rnd_bits = 32
>   vm.mmap_rnd_compat_bits = 16
>
> This breaks all the asan-enabled builds, because older asan gets
> confused by memory mappings and crashes with segmentation fault.
>
> The issue is fixed in newer releases of llvm:
>   https://github.com/llvm/llvm-project/commit/fb77ca05ffb4f8e666878f2f6718a9fb4d686839
>   https://reviews.llvm.org/D148280
>
> But these are not available in Ubuntu 22.04 image.
>
> This should be fixed by GitHub, but until new images are available
> reducing ASLR entropy manually to 28 bits to make builds work.
>
> Reported-at: https://github.com/actions/runner-images/issues/9491
> Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
> ---

Acked-by: Aaron Conole <aconole@redhat.com>

We'll probably need something similar in other projects, too... What a
mess.