1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) International Business Machines Corp., 2001
4  */
5 
6 /*
7  * DESCRIPTION
8  *
9  * 1) shmat() fails and set errno to EINVAL when shmid is invalid.
10  * 2) shmat() fails and set errno to EINVAL when shmaddr is not page
11  *    aligned and SHM_RND is not given
12  * 3) shmat() fails and set errno to EACCES when the shm resource has
13  *    no read/write permission.
14  */
15 
16 #include <errno.h>
17 #include <stdlib.h>
18 #include <sys/types.h>
19 #include <sys/ipc.h>
20 #include <sys/shm.h>
21 #include <pwd.h>
22 
23 #include "tst_test.h"
24 #include "tst_safe_sysv_ipc.h"
25 #include "libnewipc.h"
26 
27 static int shm_id1 = -1;
28 static int shm_id2 = -1;
29 static void *aligned_addr;
30 static void *unaligned_addr;
31 static key_t shm_key1;
32 static struct passwd *pw;
33 
34 static struct test_case_t {
35 	int *shmid;
36 	void **shmaddr;
37 	int exp_err;
38 	int exp_user;
39 } tcases[] = {
40 	{&shm_id1, &aligned_addr, EINVAL, 0},
41 	{&shm_id2, &unaligned_addr, EINVAL, 0},
42 	{&shm_id2, &aligned_addr, EACCES, 1},
43 };
44 
verify_shmat(struct test_case_t * tc)45 static void verify_shmat(struct test_case_t *tc)
46 {
47 	void *addr;
48 
49 	addr = shmat(*tc->shmid, *tc->shmaddr, 0);
50 	if (addr != (void *)-1) {
51 		tst_res(TFAIL, "shmat() succeeded unexpectedly");
52 		return;
53 	}
54 
55 	if (errno == tc->exp_err) {
56 		tst_res(TPASS | TERRNO, "shmat() failed as expected");
57 	} else {
58 		tst_res(TFAIL | TERRNO, "shmat() failed unexpectedly,"
59 			 "expected: %s", tst_strerrno(tc->exp_err));
60 	}
61 }
62 
do_shmat(unsigned int n)63 static void do_shmat(unsigned int n)
64 {
65 	pid_t pid;
66 
67 	struct test_case_t *tc = &tcases[n];
68 
69 	if (!tc->exp_user) {
70 		verify_shmat(tc);
71 	} else {
72 		pid = SAFE_FORK();
73 		if (pid) {
74 			tst_reap_children();
75 		} else {
76 			SAFE_SETUID(pw->pw_uid);
77 			verify_shmat(tc);
78 			exit(0);
79 		}
80 	}
81 }
82 
setup(void)83 static void setup(void)
84 {
85 	aligned_addr = PROBE_FREE_ADDR();
86 	unaligned_addr = aligned_addr + SHMLBA - 1;
87 
88 	shm_key1 = GETIPCKEY();
89 
90 	shm_id2 = SAFE_SHMGET(shm_key1, INT_SIZE, SHM_RW | IPC_CREAT | IPC_EXCL);
91 
92 	pw = SAFE_GETPWNAM("nobody");
93 }
94 
cleanup(void)95 static void cleanup(void)
96 {
97 	if (shm_id2 != -1)
98 		SAFE_SHMCTL(shm_id2, IPC_RMID, NULL);
99 }
100 
101 static struct tst_test test = {
102 	.needs_root = 1,
103 	.forks_child = 1,
104 	.test = do_shmat,
105 	.tcnt = ARRAY_SIZE(tcases),
106 	.setup = setup,
107 	.cleanup = cleanup
108 };
109