[PATCH v4 2/2] kselftest/seccomp: Report each expectation we assert as a KTAP test

From: Mark Brown
Date: Wed Jan 24 2024 - 08:02:44 EST


The seccomp benchmark test makes a number of checks on the performance it
measures and logs them to the output but does so in a custom format which
none of the automated test runners understand meaning that the chances that
anyone is paying attention are slim. Let's additionally log each result in
KTAP format so that automated systems parsing the test output will see each
comparison as a test case. The original logs are left in place since they
provide the actual numbers for analysis.

As part of this rework the flow for the main program so that when we skip
tests we still log all the tests we skip, this is because the standard KTAP
headers and footers include counts of the number of expected and run tests.

Tested-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
.../testing/selftests/seccomp/seccomp_benchmark.c | 61 +++++++++++++++-------
1 file changed, 41 insertions(+), 20 deletions(-)

diff --git a/tools/testing/selftests/seccomp/seccomp_benchmark.c b/tools/testing/selftests/seccomp/seccomp_benchmark.c
index 93168dd2c1e3..97b86980b768 100644
--- a/tools/testing/selftests/seccomp/seccomp_benchmark.c
+++ b/tools/testing/selftests/seccomp/seccomp_benchmark.c
@@ -98,24 +98,36 @@ bool le(int i_one, int i_two)
}

long compare(const char *name_one, const char *name_eval, const char *name_two,
- unsigned long long one, bool (*eval)(int, int), unsigned long long two)
+ unsigned long long one, bool (*eval)(int, int), unsigned long long two,
+ bool skip)
{
bool good;

+ if (skip) {
+ ksft_test_result_skip("%s %s %s\n", name_one, name_eval,
+ name_two);
+ return 0;
+ }
+
ksft_print_msg("\t%s %s %s (%lld %s %lld): ", name_one, name_eval, name_two,
(long long)one, name_eval, (long long)two);
if (one > INT_MAX) {
ksft_print_msg("Miscalculation! Measurement went negative: %lld\n", (long long)one);
- return 1;
+ good = false;
+ goto out;
}
if (two > INT_MAX) {
ksft_print_msg("Miscalculation! Measurement went negative: %lld\n", (long long)two);
- return 1;
+ good = false;
+ goto out;
}

good = eval(one, two);
printf("%s\n", good ? "✔️" : "❌");

+out:
+ ksft_test_result(good, "%s %s %s\n", name_one, name_eval, name_two);
+
return good ? 0 : 1;
}

@@ -142,9 +154,13 @@ int main(int argc, char *argv[])
unsigned long long samples, calc;
unsigned long long native, filter1, filter2, bitmap1, bitmap2;
unsigned long long entry, per_filter1, per_filter2;
+ bool skip = false;

setbuf(stdout, NULL);

+ ksft_print_header();
+ ksft_set_plan(7);
+
ksft_print_msg("Running on:\n");
ksft_print_msg("");
system("uname -a");
@@ -202,8 +218,10 @@ int main(int argc, char *argv[])
#define ESTIMATE(fmt, var, what) do { \
var = (what); \
ksft_print_msg("Estimated " fmt ": %llu ns\n", var); \
- if (var > INT_MAX) \
- goto more_samples; \
+ if (var > INT_MAX) { \
+ skip = true; \
+ ret |= 1; \
+ } \
} while (0)

ESTIMATE("total seccomp overhead for 1 bitmapped filter", calc,
@@ -222,30 +240,33 @@ int main(int argc, char *argv[])
(filter2 - native - entry) / 4);

ksft_print_msg("Expectations:\n");
- ret |= compare("native", "≤", "1 bitmap", native, le, bitmap1);
- bits = compare("native", "≤", "1 filter", native, le, filter1);
+ ret |= compare("native", "≤", "1 bitmap", native, le, bitmap1,
+ skip);
+ bits = compare("native", "≤", "1 filter", native, le, filter1,
+ skip);
if (bits)
- goto more_samples;
+ skip = true;

ret |= compare("per-filter (last 2 diff)", "≈", "per-filter (filters / 4)",
- per_filter1, approx, per_filter2);
+ per_filter1, approx, per_filter2, skip);

bits = compare("1 bitmapped", "≈", "2 bitmapped",
- bitmap1 - native, approx, bitmap2 - native);
+ bitmap1 - native, approx, bitmap2 - native, skip);
if (bits) {
ksft_print_msg("Skipping constant action bitmap expectations: they appear unsupported.\n");
- goto out;
+ skip = true;
}

- ret |= compare("entry", "≈", "1 bitmapped", entry, approx, bitmap1 - native);
- ret |= compare("entry", "≈", "2 bitmapped", entry, approx, bitmap2 - native);
+ ret |= compare("entry", "≈", "1 bitmapped", entry, approx,
+ bitmap1 - native, skip);
+ ret |= compare("entry", "≈", "2 bitmapped", entry, approx,
+ bitmap2 - native, skip);
ret |= compare("native + entry + (per filter * 4)", "≈", "4 filters total",
- entry + (per_filter1 * 4) + native, approx, filter2);
- if (ret == 0)
- goto out;
+ entry + (per_filter1 * 4) + native, approx, filter2,
+ skip);

-more_samples:
- ksft_print_msg("Saw unexpected benchmark result. Try running again with more samples?\n");
-out:
- return 0;
+ if (ret)
+ ksft_print_msg("Saw unexpected benchmark result. Try running again with more samples?\n");
+
+ ksft_finished();
}

--
2.30.2