enable_stats attaches its program to sys_enter, so every syscall of the
system runs it. Once the program is detached, the test compares its
run_cnt to the number of runs the program counted itself.
Detaching doesn't wait for the runs already started on other CPUs, and
each of them increments count before run_cnt. With other tests making
syscalls in parallel, the test reads run_cnt one run behind count now
and then:
test_enable_stats:FAIL:check_run_cnt_valid invalid run_cnt stats
Run the program with BPF_PROG_TEST_RUN instead of attaching it, so that
nothing else runs it and both counts are final when the test reads
them. As a single run can be shorter than the resolution of the clock,
run it until its run time shows, unless its runs aren't counted at all.
Fixes: 31a9f7fe9337 ("bpf: Add selftest for BPF_ENABLE_STATS")
Signed-off-by: Qiliang Yuan <[email protected]>
---
V1 -> V2:
- Run the program until its run time shows, as a single run can be
shorter than the resolution of the clock (Sashiko)
v1:
https://lore.kernel.org/r/20261008-selftests-bpf-enable-stats-inflight-v1-1-0cb92ee2c...@gmail.com
---
.../selftests/bpf/prog_tests/enable_stats.c | 26 +++++++++++++---------
.../selftests/bpf/progs/test_enable_stats.c | 2 +-
2 files changed, 17 insertions(+), 11 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/enable_stats.c
b/tools/testing/selftests/bpf/prog_tests/enable_stats.c
index 75f85d0fe74a4..691a82a4d6d20 100644
--- a/tools/testing/selftests/bpf/prog_tests/enable_stats.c
+++ b/tools/testing/selftests/bpf/prog_tests/enable_stats.c
@@ -9,6 +9,7 @@ void test_enable_stats(void)
struct bpf_prog_info info;
__u32 info_len = sizeof(info);
int duration = 0;
+ LIBBPF_OPTS(bpf_test_run_opts, topts);
skel = test_enable_stats__open_and_load();
if (CHECK(!skel, "skel_open_and_load", "skeleton open/load failed\n"))
@@ -20,18 +21,23 @@ void test_enable_stats(void)
return;
}
- err = test_enable_stats__attach(skel);
- if (CHECK(err, "attach_raw_tp", "err %d\n", err))
- goto cleanup;
-
- test_enable_stats__detach(skel);
-
prog_fd = bpf_program__fd(skel->progs.test_enable_stats);
- memset(&info, 0, info_len);
- err = bpf_prog_get_info_by_fd(prog_fd, &info, &info_len);
- if (CHECK(err, "get_prog_info",
- "failed to get bpf_prog_info for fd %d\n", prog_fd))
+
+ /*
+ * A single run can be too short for the clock to tell. Run the program
+ * until its run time shows, unless its runs aren't counted at all.
+ */
+ do {
+ err = bpf_prog_test_run_opts(prog_fd, &topts);
+ if (err)
+ break;
+
+ memset(&info, 0, info_len);
+ err = bpf_prog_get_info_by_fd(prog_fd, &info, &info_len);
+ } while (!err && info.run_cnt && !info.run_time_ns);
+ if (CHECK(err, "run_and_get_prog_info", "err %d\n", err))
goto cleanup;
+
if (CHECK(info.run_time_ns == 0, "check_stats_enabled",
"failed to enable run_time_ns stats\n"))
goto cleanup;
diff --git a/tools/testing/selftests/bpf/progs/test_enable_stats.c
b/tools/testing/selftests/bpf/progs/test_enable_stats.c
index 1705097d01d7b..e28d674fc77ac 100644
--- a/tools/testing/selftests/bpf/progs/test_enable_stats.c
+++ b/tools/testing/selftests/bpf/progs/test_enable_stats.c
@@ -10,7 +10,7 @@ char _license[] SEC("license") = "GPL";
__u64 count = 0;
-SEC("raw_tracepoint/sys_enter")
+SEC("raw_tp")
int test_enable_stats(void *ctx)
{
__sync_fetch_and_add(&count, 1);
---
base-commit: e1d84a37cba984388988d2f1ddc84561413f0db2
change-id: 20261008-selftests-bpf-enable-stats-inflight-edfb36a280f3
Best regards,
--
Qiliang Yuan <[email protected]>
