nptl/tst-exec5.c

   1 /* Check if posix_spawn does not act as a cancellation entrypoint.
   2    Copyright (C) 2016-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <paths.h>
  21 #include <pthread.h>
  22 #include <signal.h>
  23 #include <spawn.h>
  24 #include <stdbool.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <unistd.h>
  28 #include <sys/wait.h>
  29
  30 static int do_test (void);
  31 #define TEST_FUNCTION do_test ()
  32 #include <test-skeleton.c>
  33
  34 static pthread_barrier_t b;
  35
  36 static pid_t pid;
  37 static int pipefd[2];
  38
  39 static void *
  40 tf (void *arg)
  41 {
  42   xpthread_barrier_wait (&b);
  43
  44   posix_spawn_file_actions_t a;
  45   if (posix_spawn_file_actions_init (&a) != 0)
  46     {
  47       puts ("error: spawn_file_actions_init failed");
  48       exit (1);
  49     }
  50
  51   if (posix_spawn_file_actions_adddup2 (&a, pipefd[1], STDOUT_FILENO) != 0)
  52     {
  53       puts ("error: spawn_file_actions_adddup2 failed");
  54       exit (1);
  55     }
  56
  57   if (posix_spawn_file_actions_addclose (&a, pipefd[0]) != 0)
  58     {
  59       puts ("error: spawn_file_actions_addclose");
  60       exit (1);
  61     }
  62
  63   char *argv[] = { (char *) _PATH_BSHELL, (char *) "-c", (char *) "echo $$",
  64                    NULL };
  65   if (posix_spawn (&pid, _PATH_BSHELL, &a, NULL, argv, NULL) != 0)
  66     {
  67       puts ("error: spawn failed");
  68       exit (1);
  69     }
  70
  71   return NULL;
  72 }
  73
  74
  75 static int
  76 do_test (void)
  77 {
  78   /* The test basically pipe a 'echo $$' created by a thread with a
  79      cancellation pending.  It then checks if the thread is not cancelled,
  80      the process is created and if the output is the expected one.  */
  81
  82   if (pipe (pipefd) != 0)
  83     {
  84       puts ("error: pipe failed");
  85       exit (1);
  86     }
  87
  88   /* Not interested in knowing when the pipe is closed.  */
  89   xsignal (SIGPIPE, SIG_IGN);
  90
  91   /* To synchronize with the thread.  */
  92   if (pthread_barrier_init (&b, NULL, 2) != 0)
  93     {
  94       puts ("error: pthread_barrier_init failed");
  95       exit (1);
  96     }
  97
  98   pthread_t th = xpthread_create (NULL, &tf, NULL);
  99
 100   if (pthread_cancel (th) != 0)
 101     {
 102       puts ("error: pthread_cancel failed");
 103       return 1;
 104     }
 105
 106   xpthread_barrier_wait (&b);
 107
 108   if (xpthread_join (th) == PTHREAD_CANCELED)
 109     {
 110       puts ("error: thread cancelled");
 111       exit (1);
 112     }
 113
 114   close (pipefd[1]);
 115
 116   /* The global 'pid' should be set by thread posix_spawn calling.  Check
 117      below if it was executed correctly and with expected output.  */
 118
 119   char buf[64];
 120   ssize_t n;
 121   bool seen_pid = false;
 122   while (TEMP_FAILURE_RETRY ((n = read (pipefd[0], buf, sizeof (buf)))) > 0)
 123     {
 124       /* We only expect to read the PID.  */
 125       char *endp;
 126       long int rpid = strtol (buf, &endp, 10);
 127
 128       if (*endp != '\n')
 129         {
 130           printf ("error: didn't parse whole line: \"%s\"\n", buf);
 131           exit (1);
 132         }
 133       if (endp == buf)
 134         {
 135           puts ("error: read empty line");
 136           exit (1);
 137         }
 138
 139       if (rpid != pid)
 140         {
 141           printf ("error: found \"%s\", expected PID %ld\n", buf,
 142                  (long int) pid);
 143           exit (1);
 144         }
 145
 146       if (seen_pid)
 147         {
 148           puts ("error: found more than one PID line");
 149           exit (1);
 150         }
 151
 152       seen_pid = true;
 153     }
 154
 155   close (pipefd[0]);
 156
 157   int status;
 158   int err = waitpid (pid, &status, 0);
 159   if (err != pid)
 160     {
 161       puts ("errnor: waitpid failed");
 162       exit (1);
 163     }
 164
 165   if (!seen_pid)
 166     {
 167       puts ("error: didn't get PID");
 168       exit (1);
 169     }
 170
 171   return 0;
 172 }