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 | |