launchd/testing/our_kill_is_busted.c

   1 #include <sys/types.h>
   2 #include <sys/wait.h>
   3 #include <unistd.h>
   4 #include <assert.h>
   5 #include <errno.h>
   6 #include <string.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <signal.h>
  10
  11 int
  12 main(void)
  13 {
  14         int wstatus;
  15         pid_t p, wr;
  16         int kill_r, killpg_r, r;
  17         int kill_e, killpg_e;
  18
  19         p = fork();
  20         assert(p != -1);
  21
  22         if (p == 0) {
  23                 r = setsid();
  24                 assert(r != -1);
  25                 _exit(EXIT_SUCCESS);
  26         }
  27
  28         sleep(1);
  29
  30         errno = 0;
  31         kill_r = kill(p, SIGTERM);
  32         kill_e = errno;
  33
  34         errno = 0;
  35         killpg_r = kill(-(p), SIGTERM);
  36         killpg_e = errno;
  37
  38         if (kill_r != killpg_r) {
  39                 fprintf(stderr, "Bug. kill() is inconsistent.\n");
  40                 fprintf(stderr, "kill(   p, SIGTERM) returned %d and errno == %d\n", kill_r, kill_e);
  41                 fprintf(stderr, "kill(-(p), SIGTERM) returned %d and errno == %d\n", killpg_r, killpg_e);
  42                 if (kill_e == EPERM || killpg_e == EPERM) {
  43                         fprintf(stderr, "The kernel lied. We should have the right to kill 'p' and it returned EPERM.\n");
  44                 }
  45                 if (kill_e == ESRCH || killpg_e == ESRCH) {
  46                         fprintf(stderr, "The kernel is confused. PID 'p' exists, but the kernel couldn't find it.\n");
  47                 }
  48
  49                 exit(EXIT_FAILURE);
  50         }
  51
  52         wr = waitpid(p, &wstatus, 0);
  53         assert(wr == p);
  54
  55         exit(EXIT_SUCCESS);
  56 }