xref: /aosp_15_r20/external/ltp/testcases/kernel/syscalls/fcntl/fcntl12.c (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) Linux Test Project, 2021
4  * Copyright (c) International Business Machines  Corp., 2001
5  * 07/2001 Ported by Wayne Boyer
6  */
7 
8 /*\
9  * [Description]
10  *
11  * Tests basic error handling of the fcntl syscall.
12  *
13  * - EMFILE when cmd is F_DUPFD and the per-process limit on the number of open
14  *   file descriptors has been reached.
15  */
16 
17 #include <fcntl.h>
18 #include <sys/types.h>
19 #include <sys/wait.h>
20 #include <stdlib.h>
21 #include <unistd.h>
22 #include "tst_test.h"
23 
24 static char fname[20] = "testfile";
25 static int fd = -1, max_files;
26 
verify_fcntl(void)27 static void verify_fcntl(void)
28 {
29 	pid_t pid;
30 	int i;
31 
32 	pid = SAFE_FORK();
33 	if (pid == 0) {
34 		for (i = 0; i < max_files; i++) {
35 			fd = open(fname, O_CREAT | O_RDONLY, 0444);
36 			if (fd == -1)
37 				break;
38 		}
39 		TST_EXP_FAIL2(fcntl(1, F_DUPFD, 1), EMFILE,
40 			"fcntl(1, F_DUPFD, 1)");
41 	}
42 
43 	tst_reap_children();
44 }
45 
setup(void)46 static void setup(void)
47 {
48 	max_files = getdtablesize();
49 }
50 
cleanup(void)51 static void cleanup(void)
52 {
53 	if (fd > -1)
54 		SAFE_CLOSE(fd);
55 
56 	SAFE_UNLINK(fname);
57 }
58 
59 static struct tst_test test = {
60 	.forks_child = 1,
61 	.needs_tmpdir = 1,
62 	.setup = setup,
63 	.cleanup = cleanup,
64 	.test_all = verify_fcntl,
65 };
66