xref: /OK3568_Linux_fs/kernel/tools/testing/selftests/proc/thread-self.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * Permission to use, copy, modify, and distribute this software for any
5*4882a593Smuzhiyun  * purpose with or without fee is hereby granted, provided that the above
6*4882a593Smuzhiyun  * copyright notice and this permission notice appear in all copies.
7*4882a593Smuzhiyun  *
8*4882a593Smuzhiyun  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9*4882a593Smuzhiyun  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10*4882a593Smuzhiyun  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11*4882a593Smuzhiyun  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12*4882a593Smuzhiyun  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13*4882a593Smuzhiyun  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14*4882a593Smuzhiyun  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15*4882a593Smuzhiyun  */
16*4882a593Smuzhiyun // Test that /proc/thread-self gives correct TGID/PID.
17*4882a593Smuzhiyun #undef NDEBUG
18*4882a593Smuzhiyun #include <assert.h>
19*4882a593Smuzhiyun #include <sched.h>
20*4882a593Smuzhiyun #include <stdio.h>
21*4882a593Smuzhiyun #include <unistd.h>
22*4882a593Smuzhiyun #include <sys/mman.h>
23*4882a593Smuzhiyun #include <sys/wait.h>
24*4882a593Smuzhiyun 
25*4882a593Smuzhiyun #include "proc.h"
26*4882a593Smuzhiyun 
f(void * arg)27*4882a593Smuzhiyun int f(void *arg)
28*4882a593Smuzhiyun {
29*4882a593Smuzhiyun 	char buf1[64], buf2[64];
30*4882a593Smuzhiyun 	pid_t pid, tid;
31*4882a593Smuzhiyun 	ssize_t rv;
32*4882a593Smuzhiyun 
33*4882a593Smuzhiyun 	pid = sys_getpid();
34*4882a593Smuzhiyun 	tid = sys_gettid();
35*4882a593Smuzhiyun 	snprintf(buf1, sizeof(buf1), "%u/task/%u", pid, tid);
36*4882a593Smuzhiyun 
37*4882a593Smuzhiyun 	rv = readlink("/proc/thread-self", buf2, sizeof(buf2));
38*4882a593Smuzhiyun 	assert(rv == strlen(buf1));
39*4882a593Smuzhiyun 	buf2[rv] = '\0';
40*4882a593Smuzhiyun 	assert(streq(buf1, buf2));
41*4882a593Smuzhiyun 
42*4882a593Smuzhiyun 	if (arg)
43*4882a593Smuzhiyun 		exit(0);
44*4882a593Smuzhiyun 	return 0;
45*4882a593Smuzhiyun }
46*4882a593Smuzhiyun 
main(void)47*4882a593Smuzhiyun int main(void)
48*4882a593Smuzhiyun {
49*4882a593Smuzhiyun 	const int PAGE_SIZE = sysconf(_SC_PAGESIZE);
50*4882a593Smuzhiyun 	pid_t pid;
51*4882a593Smuzhiyun 	void *stack;
52*4882a593Smuzhiyun 
53*4882a593Smuzhiyun 	/* main thread */
54*4882a593Smuzhiyun 	f((void *)0);
55*4882a593Smuzhiyun 
56*4882a593Smuzhiyun 	stack = mmap(NULL, 2 * PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
57*4882a593Smuzhiyun 	assert(stack != MAP_FAILED);
58*4882a593Smuzhiyun 	/* side thread */
59*4882a593Smuzhiyun 	pid = clone(f, stack + PAGE_SIZE, CLONE_THREAD|CLONE_SIGHAND|CLONE_VM, (void *)1);
60*4882a593Smuzhiyun 	assert(pid > 0);
61*4882a593Smuzhiyun 	pause();
62*4882a593Smuzhiyun 
63*4882a593Smuzhiyun 	return 0;
64*4882a593Smuzhiyun }
65