Re: [PATCH 3/4] cgroup: Use __counted_by for cgroup::ancestors

[Kees Cook]

On December 19, 2025 1:09:42 AM GMT+09:00, Tejun Heo <tj@xxxxxxxxxx> wrote:
>On Thu, Dec 18, 2025 at 03:09:32PM +0800, Chen Ridong wrote:
>> Note that this level may already be used in existing BPF programs (e.g.,
>> tools/testing/selftests/bpf/progs/task_ls_uptr.c). Do we need to consider compatibility here?
>
>That's a good point. Is __counted_by instrumentation tied to some compiler
>flag? If so, might as well make it an optional extra field specifically for
>the annotation rather than changing the meaning of an existing field.
>
>Thanks.
>

CONFIG_FORTIFY_SOURCE and CONFIG_UBSAN_BOUNDS use the information for instrumentation.

-- 
Kees Cook