selftests/bpf: Fix race condition in enable_stats

In parallel execution mode, this test now need to use atomic operation
to avoid race condition.

Signed-off-by: Yucong Sun <sunyucong@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211006185619.364369-7-fallentree@fb.com

diff --git a/tools/testing/selftests/bpf/progs/test_enable_stats.c b/tools/testing/selftests/bpf/progs/test_enable_stats.c
index 01a002a..1705097 100644 (file)
--- a/tools/testing/selftests/bpf/progs/test_enable_stats.c
+++ b/tools/testing/selftests/bpf/progs/test_enable_stats.c
@@ -13,6 +13,6 @@ __u64 count = 0;
 SEC("raw_tracepoint/sys_enter")
 int test_enable_stats(void *ctx)
 {
-       count += 1;
+       __sync_fetch_and_add(&count, 1);
        return 0;
 }