Re: [PATCH 1/2] perf evsel: Add lazy-initialized probe type detection helpers

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Calling `evsel__field()` unconditionally without a `HAVE_LIBTRACEEVENT` feature guard or fallback stub causes linker errors when libtraceevent is omitted.
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commit 1f0d622399b5f71c138cdc45ef059e320a38fea7
Author: Arnaldo Carvalho de Melo <acme@redhat.com>

perf evsel: Add lazy-initialized probe type detection helpers

This commit adds helpers to lazily detect and cache whether an evsel is a
kprobe, uprobe, or ftrace-based dynamic probe. It introduces a 3-bit
probe_type field in struct evsel to avoid repeated PMU lookups.

> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
[ ... ]
> +static void evsel__resolve_probe_type(struct evsel *evsel)
> +{
> +	const char *name = evsel__pmu_name(evsel);
> +
> +	if (!strcmp(name, "kprobe"))
> +		evsel->probe_type = PROBE__KPROBE;
> +	else if (!strcmp(name, "uprobe"))
> +		evsel->probe_type = PROBE__UPROBE;
> +	else if (!strcmp(name, "tracepoint") && evsel__field(evsel, "__probe_ip"))

[Severity: High]
Will this cause a linker error when compiling without libtraceevent?

This unconditionally calls evsel__field. The actual implementation of
evsel__field is strictly wrapped in HAVE_LIBTRACEEVENT guards. Without a
fallback stub in tools/perf/util/evsel.h that returns NULL for the
!HAVE_LIBTRACEEVENT case, omitting libtraceevent could cause an undefined
reference error during linking since evsel__is_probe prevents dead-code
elimination of this function.

> +		evsel->probe_type = PROBE__FTRACE;
> +	else
> +		evsel->probe_type = PROBE__NOPE;
> +}

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Sashiko AI review · https://sashiko.dev/#/patchset/20260616154446.7206-1-acme@kernel.org?part=1