1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) International Business Machines Corp., 2001
4 * Copyright (c) 2008 Vijay Kumar B. <[email protected]>
5 * Copyright (c) Linux Test Project, 2008-2022
6 * Copyright (C) 2023 SUSE LLC Andrea Cervesato <[email protected]>
7 */
8
9 /*\
10 * [Description]
11 *
12 * Test whether writefd is set by select() when eventfd() counter value is
13 * not the maximum value, then check if writefd is not set when eventfd()
14 * counter value is maximum value.
15 */
16
17 #include <stdlib.h>
18 #include <sys/eventfd.h>
19 #include "tst_test.h"
20
run(void)21 static void run(void)
22 {
23 int fd;
24 fd_set writefds;
25 uint64_t val;
26 uint64_t non_max = 10;
27 uint64_t max = UINT64_MAX - 1;
28 struct timeval timeout = { 0, 0 };
29
30 fd = TST_EXP_FD(eventfd(0, EFD_NONBLOCK));
31
32 FD_ZERO(&writefds);
33 FD_SET(fd, &writefds);
34
35 SAFE_WRITE(0, fd, &non_max, sizeof(non_max));
36 TEST(select(fd + 1, NULL, &writefds, NULL, &timeout));
37 if (TST_RET == -1)
38 tst_brk(TBROK | TERRNO, "select");
39
40 TST_EXP_EQ_LI(FD_ISSET(fd, &writefds), 1);
41
42 SAFE_READ(0, fd, &val, sizeof(val));
43 SAFE_WRITE(0, fd, &max, sizeof(max));
44
45 TEST(select(fd + 1, NULL, &writefds, NULL, &timeout));
46 if (TST_RET == -1)
47 tst_brk(TBROK | TERRNO, "select");
48
49 TST_EXP_EQ_LI(FD_ISSET(fd, &writefds), 0);
50
51 SAFE_CLOSE(fd);
52 }
53
54 static struct tst_test test = {
55 .test_all = run,
56 .needs_kconfigs = (const char *[]) {
57 "CONFIG_EVENTFD",
58 NULL
59 },
60 };
61