Re: [PATCH] selftests: capabilities: convert error output to TAP13 ksft framework

From: Shuah Khan
Date: Thu Jul 27 2017 - 16:32:23 EST


On 07/27/2017 12:50 PM, Andy Lutomirski wrote:
> On Wed, Jul 26, 2017 at 2:18 PM, Shuah Khan <shuahkh@xxxxxxxxxxxxxxx> wrote:
>> Convert errx() and err() usage to appropriate TAP13 ksft API.
>>
>> Signed-off-by: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
>> ---
>> tools/testing/selftests/capabilities/test_execve.c | 105 ++++++++++++---------
>> .../testing/selftests/capabilities/validate_cap.c | 9 +-
>> 2 files changed, 65 insertions(+), 49 deletions(-)
>>
>> diff --git a/tools/testing/selftests/capabilities/test_execve.c b/tools/testing/selftests/capabilities/test_execve.c
>> index 7c38233292b0..cf6778441381 100644
>> --- a/tools/testing/selftests/capabilities/test_execve.c
>> +++ b/tools/testing/selftests/capabilities/test_execve.c
>> @@ -1,7 +1,6 @@
>> #define _GNU_SOURCE
>>
>> #include <cap-ng.h>
>> -#include <err.h>
>> #include <linux/capability.h>
>> #include <stdbool.h>
>> #include <string.h>
>> @@ -39,29 +38,32 @@ static void vmaybe_write_file(bool enoent_ok, char *filename, char *fmt, va_list
>> int buf_len;
>>
>> buf_len = vsnprintf(buf, sizeof(buf), fmt, ap);
>> - if (buf_len < 0) {
>> - err(1, "vsnprintf failed");
>> - }
>> - if (buf_len >= sizeof(buf)) {
>> - errx(1, "vsnprintf output truncated");
>> - }
>> + if (buf_len < 0)
>> + ksft_exit_fail_msg("vsnprintf failed - %s\n", strerror(errno));
>
> Could this not be a hypothetical ksft_exit_fail_msg_err or similar?
> Or a shorter name like ksft_fatal_err()?
>
>

Is there a reason to add _err() suffix?

ksft_exit_fail_msg() is a generic routine for a test to exit
with a test failure and print a message. The message doesn't
necessarily need to be a standard error message such as the
one err() or errx() or strerror() generate.

In some cases test could fail with a standard error condition,
but not always. In that context, it doesn't make sense to add
_err suffix. I leveraged this generic function to replace err()
and errx() usages adding strerror() not loose the important
information.

thanks,
-- Shuah