Re: [PATCH v4 2/2] selftests: Add a test mangling with uc_sigmask

[Dev Jain <dev.jain@arm.com>]

On 7/22/24 20:28, Shuah Khan wrote:
> On 7/15/24 05:49, Dev Jain wrote:
>>
>> On 6/30/24 20:48, Oleg Nesterov wrote:
>>> I see nothing wrong, but perhaps this test can be simplified?
>>> Feel free to ignore.
>>>
>>> Say,
>>>
>>> On 06/27, Dev Jain wrote:
>>>> +void handler_usr(int signo, siginfo_t *info, void *uc)
>>>> +{
>>>> +    int ret;
>>>> +
>>>> +    /*
>>>> +     * Break out of infinite recursion caused by raise(SIGUSR1) 
>>>> invoked
>>>> +     * from inside the handler
>>>> +     */
>>>> +    ++cnt;
>>>> +    if (cnt > 1)
>>>> +        return;
>>>> +
>>>> +    ksft_print_msg("In handler_usr\n");
>
> This message isn't very useful. Why do you need this message?


There isn't any specific use; I am just showing the progress

of the test. If you think this is just waste output....

>
>>>> +
>>>> +    /* SEGV blocked during handler execution, delivered on return */
>>>> +    if (raise(SIGSEGV))
>>>> +        ksft_exit_fail_perror("raise");>>> +
>>>> +    ksft_print_msg("SEGV bypassed successfully\n");
>>> You could simply do sigprocmask(SIG_SETMASK, NULL, &oldset) and 
>>> check if
>>> SIGSEGV is blocked in oldset. SIG_SETMASK has no effect if newset == 
>>> NULL.
>>>
>>
>> IMHO, isn't raising the signal, and the process not terminating, a 
>> stricter test? I have already included your described approach in
>> the last testcase; so, the test includes both ways: raising the
>> signal -> process not terminating, and checking blockage with 
>> sigprocmask().
>
> thanks,
> -- Shuah
>