On 19/04/2017 02:02, Kees Cook wrote:
> On Tue, Mar 28, 2017 at 4:46 PM, Mickaël Salaün <mic@digikod.net> wrote:
>> This is useful to return an information about the error without being
>> able to write to TH_LOG_STREAM.
>>
>> Helpers from test_harness.h may be useful outside of the seccomp
>> directory.
>>
>> Signed-off-by: Mickaël Salaün <mic@digikod.net>
>> Cc: Andy Lutomirski <luto@amacapital.net>
>> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
>> Cc: Kees Cook <keescook@chromium.org>
>> Cc: Shuah Khan <shuah@kernel.org>
>> Cc: Will Drewry <wad@chromium.org>
>> ---
>>  tools/testing/selftests/seccomp/test_harness.h | 8 +++++++-
>>  1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/testing/selftests/seccomp/test_harness.h b/tools/testing/selftests/seccomp/test_harness.h
>> index a786c69c7584..77e407663e06 100644
>> --- a/tools/testing/selftests/seccomp/test_harness.h
>> +++ b/tools/testing/selftests/seccomp/test_harness.h
>> @@ -397,7 +397,7 @@ struct __test_metadata {
>>         const char *name;
>>         void (*fn)(struct __test_metadata *);
>>         int termsig;
>> -       int passed;
>> +       __s8 passed;
> 
> Why the reduction here? int is signed too?

Because the return code of a process is capped to 8 bits and I use a
negative value to not mess with the current interpretation of 0 (error)
and 1 (OK) for the "passed" variable.

> 
>>         int trigger; /* extra handler after the evaluation */
>>         struct __test_metadata *prev, *next;
>>  };
>> @@ -476,6 +476,12 @@ void __run_test(struct __test_metadata *t)
>>                                         "instead of by signal (code: %d)\n",
>>                                         t->name,
>>                                         WEXITSTATUS(status));
>> +                       } else if (t->passed < 0) {
>> +                               fprintf(TH_LOG_STREAM,
>> +                                       "%s: Failed at step #%d\n",
>> +                                       t->name,
>> +                                       t->passed * -1);
>> +                               t->passed = 0;
>>                         }
> 
> Instead of creating an overloaded mechanism here, perhaps have an
> option reporting mechanism that can be enabled. Like adding to
> __test_metadata "bool no_stream; int test_number;" and adding
> test_number++ to each ASSERT/EXCEPT call, and doing something like:
> 
> if (t->no_stream) {
>                               fprintf(TH_LOG_STREAM,
>                                       "%s: Failed at step #%d\n",
>                                       t->name,
>                                        t->test_number);
> }
> 
> It'd be a cleaner approach, maybe?

Good idea, we will then be able to use 255 steps!

Do you want me to send this as a separate patch?

Can we move test_harness.h outside of the seccomp directory to be
available to other subsystems as well?