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Sender: Namhyung Kim <namhyung@gmail.com>
From:   Namhyung Kim <namhyung@kernel.org>
To:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Jiri Olsa <jolsa@kernel.org>
Cc:     Ian Rogers <irogers@google.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-perf-users@vger.kernel.org, bpf@vger.kernel.org,
        Song Liu <song@kernel.org>
Subject: [PATCH] perf lock contention: Fix struct rq lock access
Date:   Sun, 23 Apr 2023 14:56:50 -0700
Message-ID: <20230423215650.287812-1-namhyung@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The BPF CO-RE's ignore suffix rule requires three underscores.
Otherwise it'd fail like below:

  $ sudo perf lock contention -ab
  libbpf: prog 'collect_lock_syms': BPF program load failed: Invalid argument
  libbpf: prog 'collect_lock_syms': -- BEGIN PROG LOAD LOG --
  reg type unsupported for arg#0 function collect_lock_syms#380
  ; int BPF_PROG(collect_lock_syms)
  0: (b7) r6 = 0                        ; R6_w=0
  1: (b7) r7 = 0                        ; R7_w=0
  2: (b7) r9 = 1                        ; R9_w=1
  3: <invalid CO-RE relocation>
  failed to resolve CO-RE relocation <byte_off> [381] struct rq__new.__lock (0:0 @ offset 0)

Fixes: 0c1228486bef ("perf lock contention: Support pre-5.14 kernels")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/util/bpf_skel/lock_contention.bpf.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c
index 8911e2a077d8..30c193078bdb 100644
--- a/tools/perf/util/bpf_skel/lock_contention.bpf.c
+++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c
@@ -418,11 +418,11 @@ int contention_end(u64 *ctx)
 
 extern struct rq runqueues __ksym;
 
-struct rq__old {
+struct rq___old {
 	raw_spinlock_t lock;
 } __attribute__((preserve_access_index));
 
-struct rq__new {
+struct rq___new {
 	raw_spinlock_t __lock;
 } __attribute__((preserve_access_index));
 
@@ -434,8 +434,8 @@ int BPF_PROG(collect_lock_syms)
 
 	for (int i = 0; i < MAX_CPUS; i++) {
 		struct rq *rq = bpf_per_cpu_ptr(&runqueues, i);
-		struct rq__new *rq_new = (void *)rq;
-		struct rq__old *rq_old = (void *)rq;
+		struct rq___new *rq_new = (void *)rq;
+		struct rq___old *rq_old = (void *)rq;
 
 		if (rq == NULL)
 			break;
-- 
2.40.0.634.g4ca3ef3211-goog