Hello Michael,
On 08/06/2018 08:06 AM, Michael Ellerman wrote:
> Breno Leitao <lei...@debian.org> writes:
>
>> diff --git a/tools/testing/selftests/powerpc/harness.c
>> b/tools/testing/selftests/powerpc/harness.c
>> index 66d31de60b9a..06c51e8d8ccb 100644
>> --- a/tools/testing/selftests/powerpc/harness.c
>> +++ b/tools/testing/selftests/powerpc/harness.c
>> @@ -85,13 +85,16 @@ int run_test(int (test_function)(void), char *name)
>> return status;
>> }
>>
>> -static void alarm_handler(int signum)
>> +static void sig_handler(int signum)
>> {
>> - /* Jut wake us up from waitpid */
>> + if (signum == SIGINT)
>> + kill(-pid, SIGTERM);
>
> I don't think we need to do that here, if we just return then we'll pop
> out of the waitpid() and go via the normal path.
Correct, if we press ^C while the parent process is waiting at waitpid(),
then waitpid() syscall will be interrupted (EINTR) and never restarted again
(unless we set sa_flags = SA_RESTART), thus, the code will restart to execute
the next instruction when the signal handler is done, as we had skipped
waitpid().
>From a theoretical point of view, the user can press ^C before the process
executes waitpid() syscall. In this case and the process will not 'skip' the
waitpid(), which will continue to wait. We can clearly force this behavior
putting a sleep(1) before waitpid() and pressing ^C in the very first
second, it will 'skip' the nanosleep() syscall instead of waitpid() which
will be there, and the ^C will be ignored (thus not calling kill(-pid,
SIGTERM)).
>From a practical point of view, I will prepare a v3 patch. :-)
