[v2,2/3] posix: Refactor tst-waitid (BZ #14666)

  Changes from previous version:

  - Use sigwaitinfo instead of global variables set by the signal handler.

--

The main changes are:

  - Adapt to libsupport.
  - Synchronize the signal handler using atomics.
  - Replace waitpid by waitid calls.
  - Use support_process_state_wait to wait for child state.
  - Add tests for P_PGID and P_ALL.
  - Use sigwaitinfo instead of global state set by the signal handler.

Checked on x86_64-linux-gnu and i686-linux-gnu.
---
 posix/tst-waitid.c | 561 ++++++++++++++-------------------------------
 1 file changed, 166 insertions(+), 395 deletions(-)
  

On 18/02/2020 11:02, Adhemerval Zanella wrote:
> Changes from previous version:
> 
>   - Use sigwaitinfo instead of global variables set by the signal handler.
> 
> --
> 
> The main changes are:
> 
>   - Adapt to libsupport.
>   - Synchronize the signal handler using atomics.
>   - Replace waitpid by waitid calls.
>   - Use support_process_state_wait to wait for child state.
>   - Add tests for P_PGID and P_ALL.
>   - Use sigwaitinfo instead of global state set by the signal handler.
> 
> Checked on x86_64-linux-gnu and i686-linux-gnu.

So I did a wrong rebase and the changes required for this patch ended up on 
the third on on this set. 

> ---
>  posix/tst-waitid.c | 561 ++++++++++++++-------------------------------
>  1 file changed, 166 insertions(+), 395 deletions(-)
> 
> diff --git a/posix/tst-waitid.c b/posix/tst-waitid.c
> index c4725489ea..2331c42e66 100644
> --- a/posix/tst-waitid.c
> +++ b/posix/tst-waitid.c
> @@ -22,13 +22,20 @@
>  #include <unistd.h>
>  #include <sys/wait.h>
>  #include <signal.h>
> +#include <time.h>
> +#include <stdatomic.h>
> +#include <stdbool.h>
> +
> +#include <support/xsignal.h>
> +#include <support/xunistd.h>
> +#include <support/check.h>
> +#include <support/process_state.h>
>  
>  static void
> -test_child (void)
> +test_child (bool setgroup)
>  {
> -  /* Wait a second to be sure the parent set his variables before we
> -     produce a SIGCHLD.  */
> -  sleep (1);
> +  if (setgroup)
> +    TEST_COMPARE (setpgid (0, 0), 0);
>  
>    /* First thing, we stop ourselves.  */
>    raise (SIGSTOP);
> @@ -44,475 +51,239 @@ test_child (void)
>  # define WSTOPPED	WUNTRACED
>  #endif
>  
> -static sig_atomic_t expecting_sigchld, spurious_sigchld;
> -#ifdef SA_SIGINFO
> -static siginfo_t sigchld_info;
> +/* Set with only SIGCHLD on do_test_waitid.  */
> +static sigset_t chldset;
>  
> +#ifdef SA_SIGINFO
>  static void
>  sigchld (int signo, siginfo_t *info, void *ctx)
>  {
> -  if (signo != SIGCHLD)
> -    {
> -      printf ("SIGCHLD handler got signal %d instead!\n", signo);
> -      _exit (EXIT_FAILURE);
> -    }
> -
> -  if (! expecting_sigchld)
> -    {
> -      spurious_sigchld = 1;
> -      printf ("spurious SIGCHLD: signo %d code %d status %d pid %d\n",
> -	      info->si_signo, info->si_code, info->si_status, info->si_pid);
> -    }
> -  else
> -    {
> -      sigchld_info = *info;
> -      expecting_sigchld = 0;
> -    }
>  }
> +#endif
>  
>  static void
> -check_sigchld (const char *phase, int *ok, int code, int status, pid_t pid)
> +check_sigchld (int code, int status, pid_t pid)
>  {
> -  if (expecting_sigchld)
> -    {
> -      printf ("missing SIGCHLD on %s\n", phase);
> -      *ok = EXIT_FAILURE;
> -      expecting_sigchld = 0;
> -      return;
> -    }
> +#ifdef SA_SIGINFO
> +  siginfo_t siginfo;
> +  TEST_COMPARE (sigwaitinfo (&chldset, &siginfo), SIGCHLD);
>  
> -  if (sigchld_info.si_signo != SIGCHLD)
> -    {
> -      printf ("SIGCHLD for %s signal %d\n", phase, sigchld_info.si_signo);
> -      *ok = EXIT_FAILURE;
> -    }
> -  if (sigchld_info.si_code != code)
> -    {
> -      printf ("SIGCHLD for %s code %d\n", phase, sigchld_info.si_code);
> -      *ok = EXIT_FAILURE;
> -    }
> -  if (sigchld_info.si_status != status)
> -    {
> -      printf ("SIGCHLD for %s status %d\n", phase, sigchld_info.si_status);
> -      *ok = EXIT_FAILURE;
> -    }
> -  if (sigchld_info.si_pid != pid)
> -    {
> -      printf ("SIGCHLD for %s pid %d\n", phase, sigchld_info.si_pid);
> -      *ok = EXIT_FAILURE;
> -    }
> -}
> -# define CHECK_SIGCHLD(phase, code_check, status_check) \
> -  check_sigchld ((phase), &status, (code_check), (status_check), pid)
> -#else
> -# define CHECK_SIGCHLD(phase, code, status) ((void) 0)
> +  TEST_COMPARE (siginfo.si_signo, SIGCHLD);
> +  TEST_COMPARE (siginfo.si_code, code);
> +  TEST_COMPARE (siginfo.si_status, status);
> +  TEST_COMPARE (siginfo.si_pid, pid);
>  #endif
> +}
>  
>  static int
> -do_test (int argc, char *argv[])
> +do_test_waitd_common (idtype_t type, pid_t pid)
>  {
> -#ifdef SA_SIGINFO
> -  struct sigaction sa;
> -  sa.sa_flags = SA_SIGINFO|SA_RESTART;
> -  sa.sa_sigaction = &sigchld;
> -  if (sigemptyset (&sa.sa_mask) < 0 || sigaction (SIGCHLD, &sa, NULL) < 0)
> -    {
> -      printf ("setting SIGCHLD handler: %m\n");
> -      return EXIT_FAILURE;
> -    }
> -#endif
> +  /* Adding process_state_tracing_stop ('t') allows the test to work under
> +     trace programs such as ptrace.  */
> +  enum process_state_t stop_state = process_state_stopped
> +				    | process_state_tracing_stop;

Here is should be clearly:

  enum support_process_state stop_state = support_process_state_stopped
                                         | support_process_state_tracing_stop;

>  
> -  expecting_sigchld = 1;
> +  support_process_state_wait (pid, stop_state);
>  
> -  pid_t pid = fork ();
> -  if (pid < 0)
> -    {
> -      printf ("fork: %m\n");
> -      return EXIT_FAILURE;
> -    }
> -  else if (pid == 0)
> -    {
> -      test_child ();
> -      _exit (127);
> -    }
> -
> -  int status = EXIT_SUCCESS;
> -#define RETURN(ok) \
> -    do { if (status == EXIT_SUCCESS) status = (ok); goto out; } while (0)
> -
> -  /* Give the child a chance to stop.  */
> -  sleep (3);
> -
> -  CHECK_SIGCHLD ("stopped (before waitid)", CLD_STOPPED, SIGSTOP);
> +  check_sigchld (CLD_STOPPED, SIGSTOP, pid);
>  
>    /* Now try a wait that should not succeed.  */
>    siginfo_t info;
> +  int fail;
> +
>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
> -  int fail = waitid (P_PID, pid, &info, WEXITED|WCONTINUED|WNOHANG);
> -  switch (fail)
> -    {
> -    default:
> -      printf ("waitid returned bogus value %d\n", fail);
> -      RETURN (EXIT_FAILURE);
> -    case -1:
> -      printf ("waitid WNOHANG on stopped: %m\n");
> -      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);
> -    case 0:
> -      if (info.si_signo == 0)
> -	break;
> -      if (info.si_signo == SIGCHLD)
> -	printf ("waitid WNOHANG on stopped status %d\n", info.si_status);
> -      else
> -	printf ("waitid WNOHANG on stopped signal %d\n", info.si_signo);
> -      RETURN (EXIT_FAILURE);
> -    }
> +  fail = waitid (P_PID, pid, &info, WEXITED|WCONTINUED|WNOHANG);
> +  if (fail == -1 && errno == ENOTSUP)
> +    FAIL_RET ("waitid WNOHANG on stopped: %m");
> +  TEST_COMPARE (fail, 0);
> +  TEST_COMPARE (info.si_signo, 0);
>  
>    /* Next the wait that should succeed right away.  */
>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
>    info.si_pid = -1;
>    info.si_status = -1;
>    fail = waitid (P_PID, pid, &info, WSTOPPED|WNOHANG);
> -  switch (fail)
> -    {
> -    default:
> -      printf ("waitid WSTOPPED|WNOHANG returned bogus value %d\n", fail);
> -      RETURN (EXIT_FAILURE);
> -    case -1:
> -      printf ("waitid WSTOPPED|WNOHANG on stopped: %m\n");
> -      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);
> -    case 0:
> -      if (info.si_signo != SIGCHLD)
> -	{
> -	  printf ("waitid WSTOPPED|WNOHANG on stopped signal %d\n",
> -		  info.si_signo);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_code != CLD_STOPPED)
> -	{
> -	  printf ("waitid WSTOPPED|WNOHANG on stopped code %d\n",
> -		  info.si_code);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_status != SIGSTOP)
> -	{
> -	  printf ("waitid WSTOPPED|WNOHANG on stopped status %d\n",
> -		  info.si_status);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_pid != pid)
> -	{
> -	  printf ("waitid WSTOPPED|WNOHANG on stopped pid %d != %d\n",
> -		  info.si_pid, pid);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -    }
> +  if (fail == -1 && errno == ENOTSUP)
> +    FAIL_RET ("waitid WNOHANG on stopped: %m");
> +  TEST_COMPARE (fail, 0);
> +  TEST_COMPARE (info.si_signo, SIGCHLD);
> +  TEST_COMPARE (info.si_code, CLD_STOPPED);
> +  TEST_COMPARE (info.si_status, SIGSTOP);
> +  TEST_COMPARE (info.si_pid, pid);
>  
> -  expecting_sigchld = WCONTINUED != 0;
> +  //expecting_sigchld = WCONTINUED != 0;
>  
>    if (kill (pid, SIGCONT) != 0)
> -    {
> -      printf ("kill (%d, SIGCONT): %m\n", pid);
> -      RETURN (EXIT_FAILURE);
> -    }
> +    FAIL_RET ("kill (%d, SIGCONT): %m\n", pid);
>  
>    /* Wait for the child to have continued.  */
> -  sleep (2);
> +  support_process_state_wait (pid, process_state_sleeping);

And here it should be:

  support_process_state_wait (pid, support_process_state_sleeping);

>  
>  #if WCONTINUED != 0
> -  if (expecting_sigchld)
> -    {
> -      printf ("no SIGCHLD seen for SIGCONT (optional)\n");
> -      expecting_sigchld = 0;
> -    }
> -  else
> -    CHECK_SIGCHLD ("continued (before waitid)", CLD_CONTINUED, SIGCONT);
> +  {
> +    sigset_t set;
> +    sigemptyset (&set);
> +    sigaddset (&set, SIGCHLD);
> +    siginfo_t info;
> +    TEST_COMPARE (sigwaitinfo (&set, &info), SIGCHLD);
> +
> +    TEST_COMPARE (info.si_signo, SIGCHLD);
> +    TEST_COMPARE (info.si_code, CLD_CONTINUED);
> +    TEST_COMPARE (info.si_status, SIGCONT);
> +    TEST_COMPARE (info.si_pid, pid);
> +  }
>  
>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
>    info.si_pid = -1;
>    info.si_status = -1;
>    fail = waitid (P_PID, pid, &info, WCONTINUED|WNOWAIT);
> -  switch (fail)
> -    {
> -    default:
> -      printf ("waitid WCONTINUED|WNOWAIT returned bogus value %d\n", fail);
> -      RETURN (EXIT_FAILURE);
> -    case -1:
> -      printf ("waitid WCONTINUED|WNOWAIT on continued: %m\n");
> -      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);
> -    case 0:
> -      if (info.si_signo != SIGCHLD)
> -	{
> -	  printf ("waitid WCONTINUED|WNOWAIT on continued signal %d\n",
> -		  info.si_signo);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_code != CLD_CONTINUED)
> -	{
> -	  printf ("waitid WCONTINUED|WNOWAIT on continued code %d\n",
> -		  info.si_code);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_status != SIGCONT)
> -	{
> -	  printf ("waitid WCONTINUED|WNOWAIT on continued status %d\n",
> -		  info.si_status);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_pid != pid)
> -	{
> -	  printf ("waitid WCONTINUED|WNOWAIT on continued pid %d != %d\n",
> -		  info.si_pid, pid);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -    }
> +  if (fail == -1 && errno == ENOTSUP)
> +    FAIL_RET ("waitid WCONTINUED|WNOWAIT on continued: %m");
> +  TEST_COMPARE (fail, 0);
> +  TEST_COMPARE (info.si_signo, SIGCHLD);
> +  TEST_COMPARE (info.si_code, CLD_CONTINUED);
> +  TEST_COMPARE (info.si_status, SIGCONT);
> +  TEST_COMPARE (info.si_pid, pid);
>  
>    /* That should leave the CLD_CONTINUED state waiting to be seen again.  */
>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
>    info.si_pid = -1;
>    info.si_status = -1;
>    fail = waitid (P_PID, pid, &info, WCONTINUED);
> -  switch (fail)
> -    {
> -    default:
> -      printf ("waitid WCONTINUED returned bogus value %d\n", fail);
> -      RETURN (EXIT_FAILURE);
> -    case -1:
> -      printf ("waitid WCONTINUED on continued: %m\n");
> -      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);
> -    case 0:
> -      if (info.si_signo != SIGCHLD)
> -	{
> -	  printf ("waitid WCONTINUED on continued signal %d\n", info.si_signo);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_code != CLD_CONTINUED)
> -	{
> -	  printf ("waitid WCONTINUED on continued code %d\n", info.si_code);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_status != SIGCONT)
> -	{
> -	  printf ("waitid WCONTINUED on continued status %d\n",
> -		  info.si_status);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_pid != pid)
> -	{
> -	  printf ("waitid WCONTINUED on continued pid %d != %d\n",
> -		  info.si_pid, pid);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -    }
> +  if (fail == -1 && errno == ENOTSUP)
> +    FAIL_RET ("waitid WCONTINUED on continued: %m");
> +  TEST_COMPARE (fail, 0);
> +  TEST_COMPARE (info.si_signo, SIGCHLD);
> +  TEST_COMPARE (info.si_code, CLD_CONTINUED);
> +  TEST_COMPARE (info.si_status, SIGCONT);
> +  TEST_COMPARE (info.si_pid, pid);
>  
>    /* Now try a wait that should not succeed.  */
>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
>    fail = waitid (P_PID, pid, &info, WCONTINUED|WNOHANG);
> -  switch (fail)
> -    {
> -    default:
> -      printf ("waitid returned bogus value %d\n", fail);
> -      RETURN (EXIT_FAILURE);
> -    case -1:
> -      printf ("waitid WCONTINUED|WNOHANG on waited continued: %m\n");
> -      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);
> -    case 0:
> -      if (info.si_signo == 0)
> -	break;
> -      if (info.si_signo == SIGCHLD)
> -	printf ("waitid WCONTINUED|WNOHANG on waited continued status %d\n",
> -		info.si_status);
> -      else
> -	printf ("waitid WCONTINUED|WNOHANG on waited continued signal %d\n",
> -		info.si_signo);
> -      RETURN (EXIT_FAILURE);
> -    }
> +  if (fail == -1 && errno == ENOTSUP)
> +    FAIL_RET ("waitid WCONTINUED|WNOHANG on waited continued: %m");
> +  TEST_COMPARE (fail, 0);
> +  TEST_COMPARE (info.si_signo, 0);
>  
>    /* Now stop him again and test waitpid with WCONTINUED.  */
> -  expecting_sigchld = 1;
> +  //expecting_sigchld = 1;
>    if (kill (pid, SIGSTOP) != 0)
> -    {
> -      printf ("kill (%d, SIGSTOP): %m\n", pid);
> -      RETURN (EXIT_FAILURE);
> -    }
> +    FAIL_RET ("kill (%d, SIGSTOP): %m\n", pid);
>  
> -  /* Give the child a chance to stop.  The waitpid call below will block
> -     until it has stopped, but if we are real quick and enter the waitpid
> -     system call before the SIGCHLD has been generated, then it will be
> -     discarded and never delivered.  */
> -  sleep (3);
> +  /* Wait the child stop.  The waitid call below will block until it has
> +     stopped, but if we are real quick and enter the waitid system call
> +     before the SIGCHLD has been generated, then it will be discarded and
> +     never delivered.  */
> +  support_process_state_wait (pid, stop_state);
>  
> -  pid_t wpid = waitpid (pid, &fail, WUNTRACED);
> -  if (wpid < 0)
> -    {
> -      printf ("waitpid WUNTRACED on stopped: %m\n");
> -      RETURN (EXIT_FAILURE);
> -    }
> -  else if (wpid != pid)
> -    {
> -      printf ("waitpid WUNTRACED on stopped returned %d != %d (status %x)\n",
> -	      wpid, pid, fail);
> -      RETURN (EXIT_FAILURE);
> -    }
> -  else if (!WIFSTOPPED (fail) || WIFSIGNALED (fail) || WIFEXITED (fail)
> -	   || WIFCONTINUED (fail) || WSTOPSIG (fail) != SIGSTOP)
> -    {
> -      printf ("waitpid WUNTRACED on stopped: status %x\n", fail);
> -      RETURN (EXIT_FAILURE);
> -    }
> -  CHECK_SIGCHLD ("stopped (after waitpid)", CLD_STOPPED, SIGSTOP);
> +  fail = waitid (type, pid, &info, WEXITED|WSTOPPED);
> +  TEST_COMPARE (fail, 0);
> +  TEST_COMPARE (info.si_signo, SIGCHLD);
> +  TEST_COMPARE (info.si_code, CLD_STOPPED);
> +  TEST_COMPARE (info.si_status, SIGSTOP);
> +  TEST_COMPARE (info.si_pid, pid);
> +
> +  check_sigchld (CLD_STOPPED, SIGSTOP, pid);
>  
> -  expecting_sigchld = 1;
>    if (kill (pid, SIGCONT) != 0)
> -    {
> -      printf ("kill (%d, SIGCONT): %m\n", pid);
> -      RETURN (EXIT_FAILURE);
> -    }
> +    FAIL_RET ("kill (%d, SIGCONT): %m\n", pid);
>  
>    /* Wait for the child to have continued.  */
> -  sleep (2);
> +  support_process_state_wait (pid, process_state_sleeping);

And here it shold be:

  support_process_state_wait (pid, support_process_state_sleeping);

>  
> -  if (expecting_sigchld)
> -    {
> -      printf ("no SIGCHLD seen for SIGCONT (optional)\n");
> -      expecting_sigchld = 0;
> -    }
> -  else
> -    CHECK_SIGCHLD ("continued (before waitpid)", CLD_CONTINUED, SIGCONT);
> +  check_sigchld (CLD_CONTINUED, SIGCONT, pid);
>  
> -  wpid = waitpid (pid, &fail, WCONTINUED);
> -  if (wpid < 0)
> -    {
> -      if (errno == EINVAL)
> -	printf ("waitpid does not support WCONTINUED\n");
> -      else
> -	{
> -	  printf ("waitpid WCONTINUED on continued: %m\n");
> -	  RETURN (EXIT_FAILURE);
> -	}
> -    }
> -  else if (wpid != pid)
> -    {
> -      printf ("\
> -waitpid WCONTINUED on continued returned %d != %d (status %x)\n",
> -	     wpid, pid, fail);
> -      RETURN (EXIT_FAILURE);
> -    }
> -  else if (WIFSTOPPED (fail) || WIFSIGNALED (fail) || WIFEXITED (fail)
> -	   || !WIFCONTINUED (fail))
> -    {
> -      printf ("waitpid WCONTINUED on continued: status %x\n", fail);
> -      RETURN (EXIT_FAILURE);
> -    }
> +  fail = waitid (type, pid, &info, WCONTINUED);
> +  TEST_COMPARE (fail, 0);
> +  TEST_COMPARE (info.si_signo, SIGCHLD);
> +  TEST_COMPARE (info.si_code, CLD_CONTINUED);
> +  TEST_COMPARE (info.si_status, SIGCONT);
> +  TEST_COMPARE (info.si_pid, pid);
>  #endif
>  
> -  expecting_sigchld = 1;
> -
>    /* Die, child, die!  */
>    if (kill (pid, SIGKILL) != 0)
> -    {
> -      printf ("kill (%d, SIGKILL): %m\n", pid);
> -      RETURN (EXIT_FAILURE);
> -    }
> +    FAIL_RET ("kill (%d, SIGKILL): %m\n", pid);
>  
>  #ifdef WNOWAIT
>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
>    info.si_pid = -1;
>    info.si_status = -1;
> -  fail = waitid (P_PID, pid, &info, WEXITED|WNOWAIT);
> -  switch (fail)
> -    {
> -    default:
> -      printf ("waitid WNOWAIT returned bogus value %d\n", fail);
> -      RETURN (EXIT_FAILURE);
> -    case -1:
> -      printf ("waitid WNOWAIT on killed: %m\n");
> -      RETURN (errno == ENOTSUP ? EXIT_SUCCESS : EXIT_FAILURE);
> -    case 0:
> -      if (info.si_signo != SIGCHLD)
> -	{
> -	  printf ("waitid WNOWAIT on killed signal %d\n", info.si_signo);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_code != CLD_KILLED)
> -	{
> -	  printf ("waitid WNOWAIT on killed code %d\n", info.si_code);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_status != SIGKILL)
> -	{
> -	  printf ("waitid WNOWAIT on killed status %d\n", info.si_status);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_pid != pid)
> -	{
> -	  printf ("waitid WNOWAIT on killed pid %d != %d\n", info.si_pid, pid);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -    }
> +  fail = waitid (type, pid, &info, WEXITED|WNOWAIT);
> +  if (fail == -1 && errno == ENOTSUP)
> +    FAIL_RET ("waitid WNOHANG on killed: %m");
> +  TEST_COMPARE (fail, 0);
> +  TEST_COMPARE (info.si_signo, SIGCHLD);
> +  TEST_COMPARE (info.si_code, CLD_KILLED);
> +  TEST_COMPARE (info.si_status, SIGKILL);
> +  TEST_COMPARE (info.si_pid, pid);
>  #else
> -  /* Allow enough time to be sure the child died; we didn't synchronize.  */
> -  sleep (2);
> +  support_process_state_wait (pid, process_state_zombie);

And finally it should be:

  support_process_state_wait (pid, support_process_state_zombie);

>  #endif
> -
> -  CHECK_SIGCHLD ("killed", CLD_KILLED, SIGKILL);
> +  check_sigchld (CLD_KILLED, SIGKILL, pid);
>  
>    info.si_signo = 0;		/* A successful call sets it to SIGCHLD.  */
>    info.si_pid = -1;
>    info.si_status = -1;
> -  fail = waitid (P_PID, pid, &info, WEXITED|WNOHANG);
> -  switch (fail)
> -    {
> -    default:
> -      printf ("waitid WNOHANG returned bogus value %d\n", fail);
> -      RETURN (EXIT_FAILURE);
> -    case -1:
> -      printf ("waitid WNOHANG on killed: %m\n");
> -      RETURN (EXIT_FAILURE);
> -    case 0:
> -      if (info.si_signo != SIGCHLD)
> -	{
> -	  printf ("waitid WNOHANG on killed signal %d\n", info.si_signo);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_code != CLD_KILLED)
> -	{
> -	  printf ("waitid WNOHANG on killed code %d\n", info.si_code);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_status != SIGKILL)
> -	{
> -	  printf ("waitid WNOHANG on killed status %d\n", info.si_status);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -      if (info.si_pid != pid)
> -	{
> -	  printf ("waitid WNOHANG on killed pid %d != %d\n", info.si_pid, pid);
> -	  RETURN (EXIT_FAILURE);
> -	}
> -    }
> +  fail = waitid (type, pid, &info, WEXITED | WNOHANG);
> +  TEST_COMPARE (fail, 0);
> +  TEST_COMPARE (info.si_signo, SIGCHLD);
> +  TEST_COMPARE (info.si_code, CLD_KILLED);
> +  TEST_COMPARE (info.si_status, SIGKILL);
> +  TEST_COMPARE (info.si_pid, pid);
>  
>    fail = waitid (P_PID, pid, &info, WEXITED);
> -  if (fail == -1)
> -    {
> -      if (errno != ECHILD)
> -	{
> -	  printf ("waitid WEXITED on killed: %m\n");
> -	  RETURN (EXIT_FAILURE);
> -	}
> -    }
> -  else
> +  TEST_COMPARE (fail, -1);
> +  TEST_COMPARE (errno, ECHILD);
> +
> +  return 0;
> +}
> +
> +static int
> +do_test_waitid (idtype_t type)
> +{
> +#ifdef SA_SIGINFO
> +  {
> +    struct sigaction sa;
> +    sa.sa_flags = SA_SIGINFO | SA_RESTART;
> +    sa.sa_sigaction = sigchld;
> +    sigemptyset (&sa.sa_mask);
> +    xsigaction (SIGCHLD, &sa, NULL);
> +  }
> +#endif
> +
> +  sigemptyset (&chldset);
> +  sigaddset (&chldset, SIGCHLD);
> +
> +  /* The SIGCHLD shall has blocked at the time of the call to sigwait;
> +     otherwise, the behavior is undefined.  */
> +  sigprocmask (SIG_BLOCK, &chldset, NULL);
> +
> +  pid_t pid = xfork ();
> +  if (pid == 0)
>      {
> -      printf ("waitid WEXITED returned bogus value %d\n", fail);
> -      RETURN (EXIT_FAILURE);
> +      test_child (type == P_PGID || type == P_ALL);
> +      _exit (127);
>      }
>  
> -#undef RETURN
> - out:
> -  if (spurious_sigchld)
> -    status = EXIT_FAILURE;
> -  signal (SIGCHLD, SIG_IGN);
> +  int ret = do_test_waitd_common (type, pid);
> +
> +  xsignal (SIGCHLD, SIG_IGN);
>    kill (pid, SIGKILL);		/* Make sure it's dead if we bailed early.  */
> -  return status;
> +  return ret;
> +}
> +
> +static int
> +do_test (void)
> +{
> +  int ret = 0;
> +
> +  ret |= do_test_waitid (P_PID);
> +  ret |= do_test_waitid (P_PGID);
> +  ret |= do_test_waitid (P_ALL);
> +
> +  return ret;
>  }
>  
> -#include "../test-skeleton.c"
> +#include <support/test-driver.c>
>
  

On 18/02/2020 14:47, Adhemerval Zanella wrote:
> 
> 
> On 18/02/2020 11:02, Adhemerval Zanella wrote:
>> Changes from previous version:
>>
>>   - Use sigwaitinfo instead of global variables set by the signal handler.
>>
>> --
>>
>> The main changes are:
>>
>>   - Adapt to libsupport.
>>   - Synchronize the signal handler using atomics.
>>   - Replace waitpid by waitid calls.
>>   - Use support_process_state_wait to wait for child state.
>>   - Add tests for P_PGID and P_ALL.
>>   - Use sigwaitinfo instead of global state set by the signal handler.
>>
>> Checked on x86_64-linux-gnu and i686-linux-gnu.
> 
> So I did a wrong rebase and the changes required for this patch ended up on 
> the third on on this set. 

I will commit this patch shortly if no one opposes it.