From: Rong Tao rongtao@cestc.cn

As Jirka said [0], we just need to make sure that global ksyms initialization won't race.

[0] https://lore.kernel.org/lkml/ZPCbAs3ItjRd8XVh@krava/

Acked-by: Jiri Olsa jolsa@kernel.org Signed-off-by: Rong Tao rongtao@cestc.cn --- tools/testing/selftests/bpf/trace_helpers.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index dc4efaf538ae..4faa898ff7fc 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -7,6 +7,7 @@ #include <errno.h> #include <fcntl.h> #include <poll.h> +#include <pthread.h> #include <unistd.h> #include <linux/perf_event.h> #include <sys/mman.h> @@ -26,6 +27,7 @@ struct ksyms { };

static struct ksyms *ksyms; +static pthread_mutex_t ksyms_mutex = PTHREAD_MUTEX_INITIALIZER;

static int ksyms__add_symbol(struct ksyms *ksyms, const char *name, unsigned long addr) @@ -109,8 +111,10 @@ struct ksyms *load_kallsyms_local(void)

int load_kallsyms(void) { + pthread_mutex_lock(&ksyms_mutex); if (!ksyms) ksyms = load_kallsyms_local(); + pthread_mutex_unlock(&ksyms_mutex); return ksyms ? 0 : 1; }