xref: /aosp_15_r20/external/ltp/testcases/kernel/syscalls/getpid/getpid02.c (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) International Business Machines  Corp., 2001
4  */
5 
6 /*\
7  * [Description]
8  *
9  * Check that:
10  *
11  * - fork() in parent returns the same pid as getpid() in child
12  * - getppid() in child returns the same pid as getpid() in parent
13  */
14 
15 #include <errno.h>
16 
17 #include "tst_test.h"
18 
19 static pid_t *child_pid;
20 
verify_getpid(void)21 static void verify_getpid(void)
22 {
23 	pid_t proc_id;
24 	pid_t pid;
25 	pid_t pproc_id;
26 
27 	proc_id = getpid();
28 	pid = SAFE_FORK();
29 
30 	if (pid == 0) {
31 		pproc_id = getppid();
32 
33 		if (pproc_id != proc_id) {
34 			tst_res(TFAIL, "child getppid() (%d) != parent getpid() (%d)",
35 				pproc_id, proc_id);
36 		} else {
37 			tst_res(TPASS, "child getppid() == parent getpid() (%d)", proc_id);
38 		}
39 
40 		*child_pid = getpid();
41 
42 		return;
43 	}
44 
45 	tst_reap_children();
46 
47 	if (*child_pid != pid)
48 		tst_res(TFAIL, "child getpid() (%d) != parent fork() (%d)", *child_pid, pid);
49 	else
50 		tst_res(TPASS, "child getpid() == parent fork() (%d)", pid);
51 }
52 
setup(void)53 static void setup(void)
54 {
55 	child_pid = SAFE_MMAP(NULL, sizeof(pid_t), PROT_READ | PROT_WRITE,
56                               MAP_ANONYMOUS | MAP_SHARED, -1, 0);
57 }
58 
cleanup(void)59 static void cleanup(void)
60 {
61 	SAFE_MUNMAP(child_pid, sizeof(pid_t));
62 }
63 
64 static struct tst_test test = {
65 	.forks_child = 1,
66 	.setup = setup,
67 	.cleanup = cleanup,
68 	.test_all = verify_getpid,
69 };
70