xref: /aosp_15_r20/external/ltp/testcases/kernel/syscalls/dup/dup03.c (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
4  * Copyright (c) 2020 SUSE LLC
5  *
6  */
7 /*\
8  * [Description]
9  *
10  * Verify that dup(2) syscall fails with errno EMFILE when the per-process
11  * limit on the number of open file descriptors has been reached.
12  */
13 
14 #include <stdlib.h>
15 #include "tst_test.h"
16 
17 static int *fd;
18 static int nfds;
19 
run(void)20 static void run(void)
21 {
22 	TST_EXP_FAIL2(dup(fd[0]), EMFILE, "dup(%d)", fd[0]);
23 
24 	if (TST_RET != -1)
25 		SAFE_CLOSE(TST_RET);
26 }
27 
setup(void)28 static void setup(void)
29 {
30 	long maxfds;
31 
32 	maxfds = SAFE_SYSCONF(_SC_OPEN_MAX);
33 	fd = SAFE_MALLOC(maxfds * sizeof(int));
34 
35 	fd[0] = SAFE_OPEN("dupfile", O_RDWR | O_CREAT, 0700);
36 
37 	for (nfds = 1; nfds < maxfds; nfds++) {
38 		fd[nfds] = SAFE_DUP(fd[0]);
39 		if (fd[nfds] >= maxfds - 1)
40 			break;
41 	}
42 }
43 
cleanup(void)44 static void cleanup(void)
45 {
46 	int i;
47 
48 	for (i = 0; i < nfds; i++)
49 		SAFE_CLOSE(fd[i]);
50 }
51 
52 static struct tst_test test = {
53 	.test_all = run,
54 	.setup = setup,
55 	.cleanup = cleanup,
56 	.needs_tmpdir = 1,
57 };
58