Commit 17535a33 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

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: 1bece135 ("perf lock contention: Support old rw_semaphore type")
Reviewed-by: default avatarNamhyung Kim <namhyung@kernel.org>
Signed-off-by: default avatarIan 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent e5af1397

tools/perf/util/bpf_skel/lock_contention.bpf.c

+7 −1
Original line number Diff line number Diff line
@@ -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);