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

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");
• /* 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().