xref: /aosp_15_r20/external/ltp/testcases/kernel/syscalls/write/write02.c (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 2017 Carlo Marcelo Arenas Belon <[email protected]>
4  * Copyright (c) 2018 Cyril Hrubis <[email protected]>
5  * Copyright (c) Linux Test Project, 2003-2023
6  */
7 
8 /*\
9  * [Description]
10  *
11  * Tests for a special case NULL buffer with size 0 is expected to return 0.
12  */
13 
14 #include "tst_test.h"
15 
16 static int fd;
17 
verify_write(void)18 static void verify_write(void)
19 {
20 	TST_EXP_POSITIVE(write(fd, NULL, 0));
21 
22 	TST_EXP_EXPR(TST_RET == 0, "write(fd, NULL, %ld) == %d", TST_RET, 0);
23 }
24 
setup(void)25 static void setup(void)
26 {
27 	fd = SAFE_OPEN("test_file", O_RDWR | O_CREAT, 0700);
28 }
29 
cleanup(void)30 static void cleanup(void)
31 {
32 	if (fd > 0)
33 		SAFE_CLOSE(fd);
34 }
35 
36 static struct tst_test test = {
37 	.setup = setup,
38 	.cleanup = cleanup,
39 	.test_all = verify_write,
40 	.needs_tmpdir = 1,
41 };
42