1 /* Copyright (c) 2014 Red Hat, Inc.
2 *
3 * This program is free software: you can redistribute it and/or modify
4 * it under the terms of version 2 the GNU General Public License as
5 * published by the Free Software Foundation.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 *
12 * You should have received a copy of the GNU General Public License
13 * along with this program. If not, see <http://www.gnu.org/licenses/>.
14 ***********************************************************************
15 * File: shm_comm.c
16 *
17 * Description:
18 * 1. Clones two child processes with CLONE_NEWIPC flag, each child
19 * allocates System V shared memory segment (shm) with the _identical_
20 * key and attaches that segment into its address space.
21 * 2. Child1 writes into the shared memory segment.
22 * 3. Child2 writes into the shared memory segment.
23 * 4. Writes to the shared memory segment with the identical key but from
24 * two different IPC namespaces should not interfere with each other
25 * and so child1 checks whether its shared segment wasn't changed
26 * by child2, if it wasn't test passes, otherwise test fails.
27 */
28
29 #define _GNU_SOURCE
30 #include <sys/ipc.h>
31 #include <sys/shm.h>
32 #include <sys/types.h>
33 #include <sys/wait.h>
34 #include <stdio.h>
35 #include <errno.h>
36 #include "test.h"
37 #include "safe_macros.h"
38 #include "libclone.h"
39 #include "ipcns_helper.h"
40
41
42 #define TESTKEY 124426L
43 #define SHMSIZE 50
44 char *TCID = "shm_comm";
45 int TST_TOTAL = 1;
46
cleanup(void)47 static void cleanup(void)
48 {
49 tst_rmdir();
50 }
51
setup(void)52 static void setup(void)
53 {
54 tst_require_root();
55 check_newipc();
56 tst_tmpdir();
57 TST_CHECKPOINT_INIT(tst_rmdir);
58 }
59
chld1_shm(void * arg)60 int chld1_shm(void *arg)
61 {
62 int id, rval = 0;
63 char *shmem;
64
65 id = shmget(TESTKEY, SHMSIZE, IPC_CREAT);
66 if (id == -1) {
67 perror("shmget");
68 return 2;
69 }
70
71 if ((shmem = shmat(id, NULL, 0)) == (char *) -1) {
72 perror("shmat");
73 shmctl(id, IPC_RMID, NULL);
74 return 2;
75 }
76
77 *shmem = 'A';
78
79 TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 0);
80
81 /* if child1 shared segment has changed (by child2) report fail */
82 if (*shmem != 'A')
83 rval = 1;
84
85 /* tell child2 to continue */
86 TST_SAFE_CHECKPOINT_WAKE(NULL, 0);
87
88 shmdt(shmem);
89 shmctl(id, IPC_RMID, NULL);
90 return rval;
91 }
92
chld2_shm(void * arg)93 int chld2_shm(void *arg)
94 {
95 int id;
96 char *shmem;
97
98 id = shmget(TESTKEY, SHMSIZE, IPC_CREAT);
99 if (id == -1) {
100 perror("shmget");
101 return 2;
102 }
103
104 if ((shmem = shmat(id, NULL, 0)) == (char *) -1) {
105 perror("shmat");
106 shmctl(id, IPC_RMID, NULL);
107 return 2;
108 }
109
110 /* wait for child1 to write to his segment */
111 TST_SAFE_CHECKPOINT_WAIT(NULL, 0);
112
113 *shmem = 'B';
114
115 TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 0);
116
117 shmdt(shmem);
118 shmctl(id, IPC_RMID, NULL);
119 return 0;
120 }
121
test(void)122 static void test(void)
123 {
124 int status, ret = 0;
125
126 ret = do_clone_unshare_test(T_CLONE, CLONE_NEWIPC, chld1_shm, NULL);
127 if (ret == -1)
128 tst_brkm(TBROK | TERRNO, cleanup, "clone failed");
129
130 ret = do_clone_unshare_test(T_CLONE, CLONE_NEWIPC, chld2_shm, NULL);
131 if (ret == -1)
132 tst_brkm(TBROK | TERRNO, cleanup, "clone failed");
133
134
135 while (wait(&status) > 0) {
136 if (WIFEXITED(status) && WEXITSTATUS(status) == 1)
137 ret = 1;
138 if (WIFEXITED(status) && WEXITSTATUS(status) == 2)
139 tst_brkm(TBROK | TERRNO, cleanup, "error in child");
140 if (WIFSIGNALED(status)) {
141 tst_resm(TFAIL, "child was killed with signal %s",
142 tst_strsig(WTERMSIG(status)));
143 return;
144 }
145 }
146
147 if (ret)
148 tst_resm(TFAIL, "SysV shm: communication with identical keys"
149 " between namespaces");
150 else
151 tst_resm(TPASS, "SysV shm: communication with identical keys"
152 " between namespaces");
153 }
154
main(int argc,char * argv[])155 int main(int argc, char *argv[])
156 {
157 int lc;
158
159 tst_parse_opts(argc, argv, NULL, NULL);
160
161 setup();
162
163 for (lc = 0; TEST_LOOPING(lc); lc++)
164 test();
165
166 cleanup();
167 tst_exit();
168 }
169