[LTP] [PATCH] tst_test: Propagate SIGINT to test process

[Jan Stancek <jstancek@redhat.com>]

----- Original Message -----
> From: "Cyril Hrubis" <chrubis@suse.cz>
> To: ltp@lists.linux.it
> Cc: "Jan Stancek" <jstancek@redhat.com>
> Sent: Thursday, 4 August, 2016 4:45:08 PM
> Subject: [PATCH] tst_test: Propagate SIGINT to test process
> 
> Since the test runs in separate process and separate process group
> pressing Ctrl+C only sends SIGINT to the library process.
> 
> This commit adds SIGINT handler for the library process that kills the
> whole test process group. The upside is that system resources allocated
> in the library are cleaned up even in this case.
> 
> We also reset signal handlers in the test process after the fork now.
> 
> Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
> ---
>  lib/tst_test.c | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/tst_test.c b/lib/tst_test.c
> index 1bd2619..cd5b049 100644
> --- a/lib/tst_test.c
> +++ b/lib/tst_test.c
> @@ -724,6 +724,16 @@ static void heartbeat_handler(int sig
> LTP_ATTRIBUTE_UNUSED)
>  	alarm(results->timeout);
>  }
>  
> +#define SIGINT_MSG "Sending SIGKILL to test process...\n"
> +
> +static void sigint_handler(int sig LTP_ATTRIBUTE_UNUSED)
> +{
> +	if (test_pid > 0) {
> +		(void)write(2, SIGINT_MSG, sizeof(SIGINT_MSG) - 1);

Hi,

This still gives me a warning:
  tst_test.c: In function ‘sigint_handler’:
  tst_test.c:732:3: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Wunused-result]
   (void)write(2, SIGINT_MSG, sizeof(SIGINT_MSG) - 1);
   ^
We could use fprintf(stderr):
  fprintf(stderr, "%s\n", SIGINT_MSG);


Patch looks OK to me. I was thinking about making test pid
a foreground process group, but setup for that looked
more complex than this approach (either temporarily block
SIGTTOU or somehow synchronize lib and test pid to call
tcsetpgrp() at right moment.

Regards,
Jan

> +		kill(-test_pid, SIGKILL);
> +	}
> +}
> +
>  void tst_set_timeout(unsigned int timeout)
>  {
>  	char *mul = getenv("LTP_TIMEOUT_MUL");
> @@ -767,18 +777,23 @@ void tst_run_tcases(int argc, char *argv[], struct
> tst_test *self)
>  	else
>  		tst_set_timeout(300);
>  
> +	SAFE_SIGNAL(SIGINT, sigint_handler);
> +
>  	test_pid = fork();
>  	if (test_pid < 0)
>  		tst_brk(TBROK | TERRNO, "fork()");
>  
>  	if (!test_pid) {
> +		SAFE_SIGNAL(SIGALRM, SIG_DFL);
> +		SAFE_SIGNAL(SIGUSR1, SIG_DFL);
> +		SAFE_SIGNAL(SIGINT, SIG_DFL);
>  		SAFE_SETPGID(0, 0);
>  		testrun();
>  	}
>  
>  	SAFE_WAITPID(test_pid, &status, 0);
> -
>  	alarm(0);
> +	SAFE_SIGNAL(SIGINT, SIG_DFL);
>  
>  	if (WIFEXITED(status) && WEXITSTATUS(status))
>  		do_exit(WEXITSTATUS(status));
> --
> 2.7.3
> 
> 
> --
> Cyril Hrubis
> chrubis@suse.cz
>