xref: /aosp_15_r20/external/ltp/testcases/kernel/syscalls/ipc/shmget/shmget04.c (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) International Business Machines  Corp., 2001
4  *  03/2001 - Written by Wayne Boyer
5  */
6 
7 /*\
8  * [Description]
9  *
10  * Test for EACCES error.
11  *
12  * Create a shared memory segment without read or write permissions under
13  * unpriviledged user and call shmget() with SHM_RD/SHM_WR/SHM_RW flag to
14  * trigger EACCES error.
15  */
16 #include <errno.h>
17 #include <sys/types.h>
18 #include <sys/ipc.h>
19 #include <stdlib.h>
20 #include <pwd.h>
21 #include <sys/shm.h>
22 #include "tst_safe_sysv_ipc.h"
23 #include "tst_test.h"
24 #include "libnewipc.h"
25 #include "lapi/shm.h"
26 
27 static int shm_id = -1;
28 static key_t shmkey;
29 static struct tcase {
30 	char *message;
31 	int flag;
32 } tcases[] = {
33 	{"Testing SHM_RD flag", SHM_RD},
34 	{"Testing SHM_WR flag", SHM_WR},
35 	{"Testing SHM_RW flag", SHM_RW},
36 };
37 
verify_shmget(unsigned int n)38 static void verify_shmget(unsigned int n)
39 {
40 	struct tcase *tc = &tcases[n];
41 
42 	tst_res(TINFO, "%s", tc->message);
43 	TST_EXP_FAIL2(shmget(shmkey, SHM_SIZE, tc->flag), EACCES, "shmget(%i, %i, %i)",
44 		shmkey, SHM_SIZE, tc->flag);
45 }
46 
setup(void)47 static void setup(void)
48 {
49 	struct passwd *pw;
50 
51 	pw = SAFE_GETPWNAM("nobody");
52 	SAFE_SETUID(pw->pw_uid);
53 	shmkey = GETIPCKEY();
54 
55 	shm_id = SAFE_SHMGET(shmkey, SHM_SIZE, IPC_CREAT | IPC_EXCL);
56 }
57 
cleanup(void)58 static void cleanup(void)
59 {
60 	if (shm_id >= 0)
61 		SAFE_SHMCTL(shm_id, IPC_RMID, NULL);
62 }
63 
64 static struct tst_test test = {
65 	.needs_tmpdir = 1,
66 	.needs_root = 1,
67 	.setup = setup,
68 	.cleanup = cleanup,
69 	.test = verify_shmget,
70 	.tcnt = ARRAY_SIZE(tcases),
71 };
72