1 /*
2  * Copyright © 2018 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/thread-self gives correct TGID/PID.
17 #undef NDEBUG
18 #include <assert.h>
19 #include <sched.h>
20 #include <stdio.h>
21 #include <unistd.h>
22 #include <sys/mman.h>
23 #include <sys/wait.h>
24 
25 #include "proc.h"
26 
27 int f(void *arg)
28 {
29 	char buf1[64], buf2[64];
30 	pid_t pid, tid;
31 	ssize_t rv;
32 
33 	pid = sys_getpid();
34 	tid = sys_gettid();
35 	snprintf(buf1, sizeof(buf1), "%u/task/%u", pid, tid);
36 
37 	rv = readlink("/proc/thread-self", buf2, sizeof(buf2));
38 	assert(rv == strlen(buf1));
39 	buf2[rv] = '\0';
40 	assert(streq(buf1, buf2));
41 
42 	if (arg)
43 		exit(0);
44 	return 0;
45 }
46 
47 int main(void)
48 {
49 	const int PAGE_SIZE = sysconf(_SC_PAGESIZE);
50 	pid_t pid;
51 	void *stack;
52 
53 	/* main thread */
54 	f((void *)0);
55 
56 	stack = mmap(NULL, 2 * PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
57 	assert(stack != MAP_FAILED);
58 	/* side thread */
59 	pid = clone(f, stack + PAGE_SIZE, CLONE_THREAD|CLONE_SIGHAND|CLONE_VM, (void *)1);
60 	assert(pid > 0);
61 	pause();
62 
63 	return 0;
64 }
65