From 17535a33a9c1e4fb52f3db1d72a7ddbe4cea1a2e Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Tue, 7 Mar 2023 16:30:20 -0800 Subject: [PATCH] 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 Signed-off-by: Ian Rogers Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Martin KaFai Lau Cc: Namhyung Kim Cc: Peter Zijlstra Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230308003020.3653271-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/bpf_skel/lock_contention.bpf.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) 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 --- 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); -- 2.7.4