1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2024 Cyril Hrubis <[email protected]>
4 */
5
6 /*\
7 * [Description]
8 *
9 * Test for splicing to /dev/zero and /dev/null these two devices discard all
10 * data written to them.
11 *
12 * The support for splicing to /dev/zero was added in:
13 * 1b057bd800c3 ("drivers/char/mem: implement splice() for /dev/zero, /dev/full")
14 */
15
16 #define _GNU_SOURCE
17 #include "tst_test.h"
18
19 static const char *const test_devices[] = {
20 "/dev/null",
21 "/dev/zero",
22 };
23
verify_splice(unsigned int n)24 static void verify_splice(unsigned int n)
25 {
26 char buf[1024];
27 char dev_fd;
28 int pipefd[2];
29
30 memset(buf, 0xff, sizeof(buf));
31
32 tst_res(TINFO, "Testing %s", test_devices[n]);
33
34 dev_fd = SAFE_OPEN(test_devices[n], O_WRONLY);
35
36 SAFE_PIPE(pipefd);
37 SAFE_WRITE(1, pipefd[1], buf, sizeof(buf));
38
39 TST_EXP_POSITIVE(splice(pipefd[0], NULL, dev_fd, NULL, sizeof(buf), 0));
40
41 if (TST_PASS && TST_RET != sizeof(buf))
42 tst_res(TFAIL, "Wrote only part of the pipe buffer");
43
44 SAFE_CLOSE(pipefd[0]);
45 SAFE_CLOSE(pipefd[1]);
46 SAFE_CLOSE(dev_fd);
47 }
48
49 static struct tst_test test = {
50 .test = verify_splice,
51 .tcnt = ARRAY_SIZE(test_devices),
52 .min_kver = "6.7",
53 };
54