1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) International Business Machines Corp., 2004
4 * Copyright (c) Linux Test Project, 2004-2017
5 *
6 * DESCRIPTION
7 * hugeshmat03 - test for EACCES error
8 *
9 * ALGORITHM
10 * create a shared memory segment with root only read & write permissions
11 * fork a child process
12 * if child
13 * set the ID of the child process to that of "nobody"
14 * loop if that option was specified
15 * call shmat() using the TEST() macro
16 * check the errno value
17 * issue a PASS message if we get EACCES
18 * otherwise, the tests fails
19 * issue a FAIL message
20 * call cleanup
21 * if parent
22 * wait for child to exit
23 * remove the shared memory segment
24 *
25 * HISTORY
26 * 03/2001 - Written by Wayne Boyer
27 * 04/2004 - Updated by Robbie Williamson
28 *
29 * RESTRICTIONS
30 * test must be run at root
31 */
32
33 #include <limits.h>
34 #include "hugetlb.h"
35
36 static size_t shm_size;
37 static int shm_id_1 = -1;
38 static void *addr;
39 static uid_t ltp_uid;
40 static char *ltp_user = "nobody";
41
42 static struct tst_option options[] = {
43 {"s:", &nr_opt, "-s num Set the number of the been allocated hugepages"},
44 {NULL, NULL, NULL}
45 };
46
verify_hugeshmat(void)47 static void verify_hugeshmat(void)
48 {
49 int status;
50 pid_t pid;
51
52 switch (pid = SAFE_FORK()) {
53 case 0:
54 SAFE_SETUID(ltp_uid);
55
56 addr = shmat(shm_id_1, NULL, 0);
57 if (addr != (void *)-1) {
58 tst_res(TFAIL, "shmat succeeded unexpectedly");
59 return;
60 }
61 if (errno == EACCES) {
62 tst_res(TPASS | TERRNO, "shmat failed as expected");
63 } else {
64 tst_res(TFAIL | TERRNO, "shmat failed unexpectedly "
65 "- expect errno=EACCES, got");
66 }
67 break;
68 default:
69 SAFE_WAITPID(pid, &status, 0);
70 }
71 }
72
setup(void)73 static void setup(void)
74 {
75 long hpage_size;
76
77 if (tst_hugepages == 0)
78 tst_brk(TCONF, "No enough hugepages for testing.");
79
80 hpage_size = SAFE_READ_MEMINFO("Hugepagesize:") * 1024;
81
82 shm_size = hpage_size * tst_hugepages / 2;
83 update_shm_size(&shm_size);
84 shmkey = getipckey();
85 shm_id_1 = shmget(shmkey, shm_size,
86 SHM_HUGETLB | SHM_RW | IPC_CREAT | IPC_EXCL);
87 if (shm_id_1 == -1)
88 tst_brk(TBROK | TERRNO, "shmget");
89
90 ltp_uid = getuserid(ltp_user);
91 }
92
cleanup(void)93 static void cleanup(void)
94 {
95 rm_shm(shm_id_1);
96 }
97
98 static struct tst_test test = {
99 .needs_root = 1,
100 .forks_child = 1,
101 .needs_tmpdir = 1,
102 .options = options,
103 .test_all = verify_hugeshmat,
104 .setup = setup,
105 .cleanup = cleanup,
106 .request_hugepages = 128,
107 };
108