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
7/*
8 * DESCRIPTION
9 *	hugeshmctl03 - check for EACCES, and EPERM errors
10 *
11 * ALGORITHM
12 *	create a large shared memory segment with root only read & write
13 *	permissions fork a child process
14 *	if child
15 *	  set the ID of the child process to that of "ltpuser1"
16 *	  call do_child()
17 *	  loop if that option was specified
18 *	    call shmctl() using three different invalid cases
19 *	    check the errno value
20 *	      issue a PASS message if we get EACCES or EPERM
21 *	    otherwise, the tests fails
22 *	      issue a FAIL message
23 *	  call cleanup
24 *	if parent
25 *	  wait for child to exit
26 *	  remove the large shared memory segment
27 *
28 * HISTORY
29 *	03/2001 - Written by Wayne Boyer
30 *	04/2004 - Updated by Robbie Williamson
31 *
32 * RESTRICTIONS
33 *	test must be run as root
34 */
35
36#include <sys/types.h>
37#include <sys/wait.h>
38#include <limits.h>
39#include "hugetlb.h"
40
41static size_t shm_size;
42static int shm_id_1 = -1;
43static struct shmid_ds buf;
44static uid_t test_uid;
45static char *test_user = "nobody";
46
47static struct tcase {
48	int *shmid;
49	int cmd;
50	struct shmid_ds *sbuf;
51	int error;
52} tcases[] = {
53	/* EACCES - child has no read permission for segment */
54	{&shm_id_1, IPC_STAT, &buf, EACCES},
55	/* EPERM - IPC_SET - child doesn't have permission to change segment */
56	{&shm_id_1, IPC_SET, &buf, EPERM},
57	/* EPERM - IPC_RMID - child can not remove the segment */
58	{&shm_id_1, IPC_RMID, &buf, EPERM},
59};
60
61static void do_child(void);
62
63static void test_hugeshmctl(void)
64{
65	pid_t pid;
66	int status;
67
68	switch (pid = SAFE_FORK()) {
69	case 0:
70		/* set the user ID of the child to the non root user */
71		SAFE_SETUID(test_uid);
72		do_child();
73		exit(0);
74	default:
75		SAFE_WAITPID(pid, &status, 0);
76	}
77}
78
79static void do_child(void)
80{
81	unsigned int i;
82
83	for (i = 0; i < ARRAY_SIZE(tcases); i++) {
84		TEST(shmctl(*(tcases[i].shmid), tcases[i].cmd, tcases[i].sbuf));
85		if (TST_RET != -1) {
86			tst_res(TFAIL, "shmctl succeeded "
87					"unexpectedly");
88			continue;
89		}
90		if (TST_ERR == tcases[i].error)
91			tst_res(TPASS | TTERRNO, "shmctl failed "
92					"as expected");
93		else
94			tst_res(TFAIL | TTERRNO, "shmctl failed "
95					"unexpectedly - expect errno = "
96					"%d, got", tcases[i].error);
97	}
98}
99
100static void setup(void)
101{
102	long hpage_size;
103
104	if (tst_hugepages == 0)
105		tst_brk(TCONF, "No enough hugepages for testing.");
106
107	hpage_size = SAFE_READ_MEMINFO("Hugepagesize:") * 1024;
108
109	shm_size = hpage_size * tst_hugepages / 2;
110	update_shm_size(&shm_size);
111	shmkey = getipckey();
112	shm_id_1 = shmget(shmkey, shm_size,
113			  SHM_HUGETLB | IPC_CREAT | IPC_EXCL | SHM_RW);
114	if (shm_id_1 == -1)
115		tst_brk(TBROK | TERRNO, "shmget");
116
117	/* get the userid for a non root user */
118	test_uid = getuserid(test_user);
119}
120
121static void cleanup(void)
122{
123	rm_shm(shm_id_1);
124}
125
126static struct tst_test test = {
127	.needs_root = 1,
128	.forks_child = 1,
129	.needs_tmpdir = 1,
130	.options = (struct tst_option[]) {
131		{"s:", &nr_opt, "Set the number of the been allocated hugepages"},
132		{}
133	},
134	.setup = setup,
135	.cleanup = cleanup,
136	.test_all = test_hugeshmctl,
137	.hugepages = {128, TST_REQUEST},
138};
139