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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 2014 Red Hat, Inc.
4  * Copyright (C) 2022 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
5  */
6 
7 /*\
8  * [Description]
9  *
10  * Test if SysV IPC shared memory is properly working between two different
11  * namespaces.
12  *
13  * [Algorithm]
14  *
15  * 1. Clones two child processes with CLONE_NEWIPC flag, each child
16  *    allocates System V shared memory segment (shm) with the _identical_
17  *    key and attaches that segment into its address space.
18  * 2. Child1 writes into the shared memory segment.
19  * 3. Child2 writes into the shared memory segment.
20  * 4. Writes to the shared memory segment with the identical key but from
21  *    two different IPC namespaces should not interfere with each other
22  *    and so child1 checks whether its shared segment wasn't changed
23  *    by child2, if it wasn't test passes, otherwise test fails.
24  */
25 
26 #define _GNU_SOURCE
27 
28 #include <sys/wait.h>
29 #include <sys/msg.h>
30 #include <sys/types.h>
31 #include "tst_safe_sysv_ipc.h"
32 #include "tst_test.h"
33 #include "common.h"
34 
35 #define TESTKEY 124426L
36 #define SHMSIZE 50
37 
chld1_shm(LTP_ATTRIBUTE_UNUSED void * arg)38 static int chld1_shm(LTP_ATTRIBUTE_UNUSED void *arg)
39 {
40 	int id;
41 	char *shmem;
42 
43 	id = SAFE_SHMGET(TESTKEY, SHMSIZE, IPC_CREAT);
44 
45 	shmem = SAFE_SHMAT(id, NULL, 0);
46 	*shmem = 'A';
47 
48 	TST_CHECKPOINT_WAKE_AND_WAIT(0);
49 
50 	if (*shmem != 'A')
51 		tst_res(TFAIL, "shared memory leak between namespaces");
52 	else
53 		tst_res(TPASS, "shared memory didn't leak between namespaces");
54 
55 	TST_CHECKPOINT_WAKE(0);
56 
57 	SAFE_SHMDT(shmem);
58 	SAFE_SHMCTL(id, IPC_RMID, NULL);
59 
60 	return 0;
61 }
62 
chld2_shm(LTP_ATTRIBUTE_UNUSED void * arg)63 static int chld2_shm(LTP_ATTRIBUTE_UNUSED void *arg)
64 {
65 	int id;
66 	char *shmem;
67 
68 	id = SAFE_SHMGET(TESTKEY, SHMSIZE, IPC_CREAT);
69 
70 	shmem = SAFE_SHMAT(id, NULL, 0);
71 
72 	TST_CHECKPOINT_WAIT(0);
73 
74 	*shmem = 'B';
75 
76 	TST_CHECKPOINT_WAKE_AND_WAIT(0);
77 
78 	SAFE_SHMDT(shmem);
79 	SAFE_SHMCTL(id, IPC_RMID, NULL);
80 
81 	return 0;
82 }
83 
run(void)84 static void run(void)
85 {
86 	clone_unshare_test(T_CLONE, CLONE_NEWIPC, chld1_shm, NULL);
87 	clone_unshare_test(T_CLONE, CLONE_NEWIPC, chld2_shm, NULL);
88 }
89 
setup(void)90 static void setup(void)
91 {
92 	check_newipc();
93 }
94 
95 static struct tst_test test = {
96 	.test_all = run,
97 	.setup = setup,
98 	.needs_root = 1,
99 	.needs_checkpoints = 1,
100 };
101