On Thu, Apr 27, 2023 at 4:48 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> 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@xxxxxxxxxx>
Acked-by: Ian Rogers <irogers@xxxxxxxxxx>
Thanks,
Ian
> ---
> 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;
> --
> 2.40.1.495.gc816e09b53d-goog
>
