1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 2015 Cedric Hnyda <chnyda@suse.com>
4  */
5 
6  /* Description:
7  *   Verify that:
8  *		1) kcmp returns 0 with two process and two fd refering to the
9  *			same open file
10  *		2) kcmp doesn't return 0 with two process and two fd not
11  *		   refering to the same open file
12  */
13 
14 #define _GNU_SOURCE
15 
16 #include "tst_test.h"
17 #include "lapi/fcntl.h"
18 #include "kcmp.h"
19 
20 #define TEST_FILE "test_file"
21 #define TEST_FILE2 "test_file2"
22 
23 static int fd1;
24 static int fd2;
25 static int fd3;
26 static int pid1;
27 static int pid2;
28 
29 static struct test_case {
30 	int *pid1;
31 	int *pid2;
32 	int type;
33 	int *fd1;
34 	int *fd2;
35 	int exp_different;
36 } test_cases[] = {
37 	{&pid1, &pid1, KCMP_FILE, &fd1, &fd1, 0},
38 	{&pid2, &pid2, KCMP_FILE, &fd1, &fd2, 0},
39 	{&pid1, &pid2, KCMP_FILE, &fd1, &fd1, 0},
40 	{&pid1, &pid2, KCMP_FILE, &fd1, &fd2, 0},
41 	{&pid1, &pid2, KCMP_FILE, &fd1, &fd3, 1},
42 };
43 
setup(void)44 static void setup(void)
45 {
46 	fd1 = SAFE_OPEN(TEST_FILE, O_CREAT | O_RDWR | O_TRUNC);
47 }
48 
cleanup(void)49 static void cleanup(void)
50 {
51 	if (fd1 > 0)
52 		SAFE_CLOSE(fd1);
53 }
54 
do_child(const struct test_case * test)55 static void do_child(const struct test_case *test)
56 {
57 	pid2 = getpid();
58 
59 	fd3 = SAFE_OPEN(TEST_FILE2, O_CREAT | O_RDWR, 0666);
60 
61 	fd2 = dup(fd1);
62 	if (fd2 == -1) {
63 		tst_res(TFAIL | TERRNO, "dup() failed unexpectedly");
64 		SAFE_CLOSE(fd3);
65 		return;
66 	}
67 
68 	TEST(kcmp(*(test->pid1), *(test->pid2), test->type,
69 		  *(test->fd1), *(test->fd2)));
70 
71 	SAFE_CLOSE(fd2);
72 	SAFE_CLOSE(fd3);
73 
74 	if (TST_RET == -1) {
75 		tst_res(TFAIL | TTERRNO, "kcmp() failed unexpectedly");
76 		return;
77 	}
78 
79 	if ((test->exp_different && TST_RET == 0)
80 		|| (test->exp_different == 0 && TST_RET)) {
81 		tst_res(TFAIL, "kcmp() returned %lu instead of %d",
82 			TST_RET, test->exp_different);
83 		return;
84 	}
85 
86 	tst_res(TPASS, "kcmp() returned the expected value");
87 }
88 
verify_kcmp(unsigned int n)89 static void verify_kcmp(unsigned int n)
90 {
91 	struct test_case *tc = &test_cases[n];
92 
93 	pid1 = getpid();
94 
95 	pid2 = SAFE_FORK();
96 	if (!pid2)
97 		do_child(tc);
98 }
99 
100 static struct tst_test test = {
101 	.tcnt = ARRAY_SIZE(test_cases),
102 	.setup = setup,
103 	.cleanup = cleanup,
104 	.forks_child = 1,
105 	.test = verify_kcmp,
106 	.min_kver = "3.5.0",
107 	.needs_tmpdir = 1,
108 };
109