perf lock contention: Fix compiler builtin detection

__has_builtin was passed the macro rather than the actual builtin
feature. The builtin test isn't sufficient and a clang version test
also needs to be performed.

Fixes: 1bece1351c653c3d ("perf lock contention: Support old rw_semaphore type")
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <martin.lau@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230308003020.3653271-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c
index e6007ea..141b36d 100644 (file)
--- a/tools/perf/util/bpf_skel/lock_contention.bpf.c
+++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c
@@ -182,7 +182,13 @@ static inline struct task_struct *get_lock_owner(__u64 lock, __u32 flags)
                struct mutex *mutex = (void *)lock;
                owner = BPF_CORE_READ(mutex, owner.counter);
        } else if (flags == LCB_F_READ || flags == LCB_F_WRITE) {
-#if __has_builtin(bpf_core_type_matches)
+       /*
+        * Support for the BPF_TYPE_MATCHES argument to the
+        * __builtin_preserve_type_info builtin was added at some point during
+        * development of clang 15 and it's what is needed for
+        * bpf_core_type_matches.
+        */
+#if __has_builtin(__builtin_preserve_type_info) && __clang_major__ >= 15
                if (bpf_core_type_matches(struct rw_semaphore___old)) {
                        struct rw_semaphore___old *rwsem = (void *)lock;
                        owner = (unsigned long)BPF_CORE_READ(rwsem, owner);