1 /* 2 * Copyright (c) 2021 Alexey Dobriyan <adobriyan@gmail.com> 3 * 4 * Permission to use, copy, modify, and distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15 */ 16 // Test that /proc/*/task never contains "0". 17 #include <sys/types.h> 18 #include <dirent.h> 19 #include <signal.h> 20 #include <stdio.h> 21 #include <stdlib.h> 22 #include <string.h> 23 #include <unistd.h> 24 #include <pthread.h> 25 26 static pid_t pid = -1; 27 28 static void atexit_hook(void) 29 { 30 if (pid > 0) { 31 kill(pid, SIGKILL); 32 } 33 } 34 35 static void *f(void *_) 36 { 37 return NULL; 38 } 39 40 static void sigalrm(int _) 41 { 42 exit(0); 43 } 44 45 int main(void) 46 { 47 pid = fork(); 48 if (pid == 0) { 49 /* child */ 50 while (1) { 51 pthread_t pth; 52 pthread_create(&pth, NULL, f, NULL); 53 pthread_join(pth, NULL); 54 } 55 } else if (pid > 0) { 56 /* parent */ 57 atexit(atexit_hook); 58 59 char buf[64]; 60 snprintf(buf, sizeof(buf), "/proc/%u/task", pid); 61 62 signal(SIGALRM, sigalrm); 63 alarm(1); 64 65 while (1) { 66 DIR *d = opendir(buf); 67 struct dirent *de; 68 while ((de = readdir(d))) { 69 if (strcmp(de->d_name, "0") == 0) { 70 exit(1); 71 } 72 } 73 closedir(d); 74 } 75 76 return 0; 77 } else { 78 perror("fork"); 79 return 1; 80 } 81 } 82