Linux 6.12.91 / build breakage / perf cgroup: Update metric leader in evlist__expand_cgroup

Linux 6.12.91 / build breakage / perf cgroup: Update metric leader in evlist__expand_cgroup

[Marek Vasut]

Hello everyone,

the following commit landed in Linux 6.12.91:

d26e31446c0f ("perf cgroup: Update metric leader in evlist__expand_cgroup")

However, the first_wildcard_match field does not exist in Linux 6.12.91, 
which prevents perf from being built:

"
$ git grep first_wildcard_match
tools/perf/util/cgroup.c:                       if 
(pos->first_wildcard_match)
tools/perf/util/cgroup.c: 
evsel->first_wildcard_match = pos->first_wildcard_match->priv;
"

Either this commit should be dropped, or 137359b7895f ("perf 
parse-events: Use wildcard processing to set an event to merge into") 
needs to be backported too (?).

Furthermore, it also seems 7cfcd01f33fc ("perf tool_pmu: Factor tool 
events into their own PMU") calls parse_events__term_type_str() which is 
also not defined on 6.12.y .

Thank you for your help !
-- 
Best regards,
Marek Vasut

Re: Linux 6.12.91 / build breakage / perf cgroup: Update metric leader in evlist__expand_cgroup

[Sasha Levin]

> So either revert these two commits, drop them, or also backport
> 137359b7895f61cd07fcdbaf9d195567bde8cc85 ?

Went with the revert path on 6.12 as 137359b7 is a larger non-stable refactor
that I'd rather not pull in just to satisfy a build prerequisite. 7cfcd01f33fc
had two newer dependents (the duration_time fix and the python parse_events
addition) that conflicted with reverting it alone, so I chained the reverts to
keep the tree buildable. This re-introduces the perf cgroup UAF that
c9ef786c0970 was fixing - if the perf folks would prefer to backport the
missing prereqs (d2f3ecb0 + 137359b7) instead, happy to swap approaches.

-- 
Thanks,
Sasha