xref: /aosp_15_r20/external/ltp/testcases/kernel/syscalls/pidfd_getfd/pidfd_getfd01.c (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 2022 FUJITSU LIMITED. All rights reserved.
4  * Author: Yang Xu <[email protected]>
5  */
6 
7 /*\
8  * [Description]
9  *
10  * Basic pidfd_getfd() test:
11  *
12  * - the close-on-exec flag is set on the file descriptor returned by
13  *   pidfd_getfd
14  * - use kcmp to check whether a file descriptor idx1 in the process pid1
15  *   refers to the same open file description as file descriptor idx2 in
16  *   the process pid2
17  */
18 
19 #include <unistd.h>
20 #include <stdlib.h>
21 #include <stdio.h>
22 #include "tst_test.h"
23 #include "lapi/kcmp.h"
24 #include "tst_safe_macros.h"
25 #include "lapi/pidfd.h"
26 
27 #define TESTFILE "testfile"
28 
29 static int fds[2] = {-1, -1};
30 static int pidfd = -1;
31 
do_child(void)32 static void do_child(void)
33 {
34 	int fd;
35 
36 	SAFE_CLOSE(fds[0]);
37 	fd = SAFE_CREAT(TESTFILE, 0644);
38 	SAFE_WRITE(SAFE_WRITE_ALL, fds[1], &fd, sizeof(fd));
39 	TST_CHECKPOINT_WAIT(0);
40 	SAFE_CLOSE(fd);
41 	SAFE_CLOSE(fds[1]);
42 	exit(0);
43 }
44 
run(void)45 static void run(void)
46 {
47 	int flag, pid, targetfd, remotefd;
48 
49 	SAFE_PIPE(fds);
50 	pid = SAFE_FORK();
51 	if (!pid)
52 		do_child();
53 
54 	SAFE_CLOSE(fds[1]);
55 	TST_PROCESS_STATE_WAIT(pid, 'S', 0);
56 
57 	pidfd = SAFE_PIDFD_OPEN(pid, 0);
58 	SAFE_READ(1, fds[0], &targetfd, sizeof(targetfd));
59 	TST_EXP_FD_SILENT(pidfd_getfd(pidfd, targetfd, 0),
60 		"pidfd_getfd(%d, %d , 0)", pidfd, targetfd);
61 
62 	remotefd = TST_RET;
63 	flag = SAFE_FCNTL(remotefd, F_GETFD);
64 	if (!(flag & FD_CLOEXEC))
65 		tst_res(TFAIL, "pidfd_getfd() didn't set close-on-exec flag");
66 
67 	TST_EXP_VAL_SILENT(kcmp(getpid(), pid, KCMP_FILE, remotefd, targetfd), 0);
68 
69 	tst_res(TPASS, "pidfd_getfd(%d, %d, 0) passed", pidfd, targetfd);
70 
71 	TST_CHECKPOINT_WAKE(0);
72 	SAFE_CLOSE(remotefd);
73 	SAFE_CLOSE(pidfd);
74 	SAFE_CLOSE(fds[0]);
75 	tst_reap_children();
76 }
77 
setup(void)78 static void setup(void)
79 {
80 	pidfd_open_supported();
81 	pidfd_getfd_supported();
82 }
83 
cleanup(void)84 static void cleanup(void)
85 {
86 	if (fds[0] > -1)
87 		SAFE_CLOSE(fds[0]);
88 	if (fds[1] > -1)
89 		SAFE_CLOSE(fds[1]);
90 	if (pidfd > -1)
91 		SAFE_CLOSE(pidfd);
92 }
93 
94 static struct tst_test test = {
95 	.needs_root = 1,
96 	.needs_checkpoints = 1,
97 	.forks_child = 1,
98 	.setup = setup,
99 	.cleanup = cleanup,
100 	.test_all = run,
101 };
102