Re: [PATCH v1] selftests: Enhance kselftest_harness.h to print which assert failed

From: MickaÃl SalaÃn
Date: Tue Sep 05 2017 - 16:39:04 EST



On 28/08/2017 18:42, Shuah Khan wrote:
> On 08/06/2017 05:23 PM, MickaÃl SalaÃn wrote:
>> When a test process is not able to write to TH_LOG_STREAM, this step
>> mechanism enable to print the assert number which triggered the failure.
>> This can be enabled by setting _metadata->no_print to true at the
>> beginning of the test sequence.
>>
>> Update the seccomp-bpf test to return 0 if a test succeeded.
>>
>> This feature is needed for the Landlock tests.
>>
>> Signed-off-by: MickaÃl SalaÃn <mic@xxxxxxxxxxx>
>> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
>> Cc: Kees Cook <keescook@xxxxxxxxxxxx>
>> Cc: Shuah Khan <shuah@xxxxxxxxxx>
>> Cc: Will Drewry <wad@xxxxxxxxxxxx>
>> Link: https://lkml.kernel.org/r/CAGXu5j+D-FP8Kt9unNOqKrQJP4DYTpmgkJxWykZyrYiVPz3Y3Q@xxxxxxxxxxxxxx
>
> I am looking through my Inbox and found this one. Okay to pull
> this in for 4.14-rc1?

Yes, could you please pull this one instead of the one from my Landlock
patch series [1] (which is already in your tree)? This patch is more
up-to-date and include documentation.

Thanks,
MickaÃl


[1]
https://lkml.kernel.org/r/af24658e-4225-118e-59aa-0b78d6227cb8@xxxxxxxxxx


>> ---
>>
>> Changes since the patch from the Landlock series:
>> * add the step counter in assert/expect macros and use _metadata to
>> enable the counter (suggested by Kees Cook)
>> * only count asserts
>> * add documentation
>> ---
>> tools/testing/selftests/kselftest_harness.h | 39 +++++++++++++++++++++++----
>> tools/testing/selftests/seccomp/seccomp_bpf.c | 2 +-
>> 2 files changed, 35 insertions(+), 6 deletions(-)
>>
>> diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
>> index c56f72e07cd7..e81bd28bdd89 100644
>> --- a/tools/testing/selftests/kselftest_harness.h
>> +++ b/tools/testing/selftests/kselftest_harness.h
>> @@ -51,6 +51,9 @@
>> #define __KSELFTEST_HARNESS_H
>>
>> #define _GNU_SOURCE
>> +#include <asm/types.h>
>> +#include <errno.h>
>> +#include <stdbool.h>
>> #include <stdint.h>
>> #include <stdio.h>
>> #include <stdlib.h>
>> @@ -84,6 +87,14 @@
>> * E.g., #define TH_LOG_ENABLED 1
>> *
>> * If no definition is provided, logging is enabled by default.
>> + *
>> + * If there is no way to print an error message for the process running the
>> + * test (e.g. not allowed to write to stderr), it is still possible to get the
>> + * ASSERT_* number for which the test failed. This behavior can be enabled by
>> + * writing `_metadata->no_print = true;` before the check sequence that is
>> + * unable to print. When an error occur, instead of printing an error message
>> + * and calling `abort(3)`, the test process call `_exit(2)` with the assert
>> + * number as argument, which is then printed by the parent process.
>> */
>> #define TH_LOG(fmt, ...) do { \
>> if (TH_LOG_ENABLED) \
>> @@ -555,12 +566,18 @@
>> * return while still providing an optional block to the API consumer.
>> */
>> #define OPTIONAL_HANDLER(_assert) \
>> - for (; _metadata->trigger; _metadata->trigger = __bail(_assert))
>> + for (; _metadata->trigger; _metadata->trigger = \
>> + __bail(_assert, _metadata->no_print, _metadata->step))
>> +
>> +#define __INC_STEP(_metadata) \
>> + if (_metadata->passed && _metadata->step < 255) \
>> + _metadata->step++;
>>
>> #define __EXPECT(_expected, _seen, _t, _assert) do { \
>> /* Avoid multiple evaluation of the cases */ \
>> __typeof__(_expected) __exp = (_expected); \
>> __typeof__(_seen) __seen = (_seen); \
>> + if (_assert) __INC_STEP(_metadata); \
>> if (!(__exp _t __seen)) { \
>> unsigned long long __exp_print = (uintptr_t)__exp; \
>> unsigned long long __seen_print = (uintptr_t)__seen; \
>> @@ -576,6 +593,7 @@
>> #define __EXPECT_STR(_expected, _seen, _t, _assert) do { \
>> const char *__exp = (_expected); \
>> const char *__seen = (_seen); \
>> + if (_assert) __INC_STEP(_metadata); \
>> if (!(strcmp(__exp, __seen) _t 0)) { \
>> __TH_LOG("Expected '%s' %s '%s'.", __exp, #_t, __seen); \
>> _metadata->passed = 0; \
>> @@ -590,6 +608,8 @@ struct __test_metadata {
>> int termsig;
>> int passed;
>> int trigger; /* extra handler after the evaluation */
>> + __u8 step;
>> + bool no_print; /* manual trigger when TH_LOG_STREAM is not available */
>> struct __test_metadata *prev, *next;
>> };
>>
>> @@ -634,10 +654,13 @@ static inline void __register_test(struct __test_metadata *t)
>> }
>> }
>>
>> -static inline int __bail(int for_realz)
>> +static inline int __bail(int for_realz, bool no_print, __u8 step)
>> {
>> - if (for_realz)
>> + if (for_realz) {
>> + if (no_print)
>> + _exit(step);
>> abort();
>> + }
>> return 0;
>> }
>>
>> @@ -655,18 +678,24 @@ void __run_test(struct __test_metadata *t)
>> t->passed = 0;
>> } else if (child_pid == 0) {
>> t->fn(t);
>> - _exit(t->passed);
>> + /* return the step that failed or 0 */
>> + _exit(t->passed ? 0 : t->step);
>> } else {
>> /* TODO(wad) add timeout support. */
>> waitpid(child_pid, &status, 0);
>> if (WIFEXITED(status)) {
>> - t->passed = t->termsig == -1 ? WEXITSTATUS(status) : 0;
>> + t->passed = t->termsig == -1 ? !WEXITSTATUS(status) : 0;
>> if (t->termsig != -1) {
>> fprintf(TH_LOG_STREAM,
>> "%s: Test exited normally "
>> "instead of by signal (code: %d)\n",
>> t->name,
>> WEXITSTATUS(status));
>> + } else if (!t->passed) {
>> + fprintf(TH_LOG_STREAM,
>> + "%s: Test failed at step #%d\n",
>> + t->name,
>> + WEXITSTATUS(status));
>> }
>> } else if (WIFSIGNALED(status)) {
>> t->passed = 0;
>> diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
>> index 73f5ea6778ce..4d6f92a9df6b 100644
>> --- a/tools/testing/selftests/seccomp/seccomp_bpf.c
>> +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
>> @@ -107,7 +107,7 @@ TEST(mode_strict_support)
>> ASSERT_EQ(0, ret) {
>> TH_LOG("Kernel does not support CONFIG_SECCOMP");
>> }
>> - syscall(__NR_exit, 1);
>> + syscall(__NR_exit, 0);
>> }
>>
>> TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL)
>>
>
>

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