1 | /* Basic tests for Linux SYSV semaphore extensions. |
2 | Copyright (C) 2020-2024 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <sys/ipc.h> |
20 | #include <sys/sem.h> |
21 | #include <errno.h> |
22 | #include <stdlib.h> |
23 | #include <stdbool.h> |
24 | #include <stdio.h> |
25 | |
26 | #include <support/check.h> |
27 | #include <support/temp_file.h> |
28 | |
29 | /* These are for the temporary file we generate. */ |
30 | static char *name; |
31 | static int semid; |
32 | |
33 | static void |
34 | remove_sem (void) |
35 | { |
36 | /* Enforce message queue removal in case of early test failure. |
37 | Ignore error since the sem may already have being removed. */ |
38 | semctl (semid: semid, semnum: 0, IPC_RMID, 0); |
39 | } |
40 | |
41 | static void |
42 | do_prepare (int argc, char *argv[]) |
43 | { |
44 | TEST_VERIFY_EXIT (create_temp_file ("tst-sysvsem." , &name) != -1); |
45 | } |
46 | |
47 | #define PREPARE do_prepare |
48 | |
49 | #define SEM_MODE 0644 |
50 | |
51 | union semun |
52 | { |
53 | int val; |
54 | struct semid_ds *buf; |
55 | unsigned short *array; |
56 | struct seminfo *__buf; |
57 | }; |
58 | |
59 | struct test_seminfo |
60 | { |
61 | int semmsl; |
62 | int semmns; |
63 | int semopm; |
64 | int semmni; |
65 | }; |
66 | |
67 | /* It tries to obtain some system-wide SysV semaphore information from /proc |
68 | to check against IPC_INFO/SEM_INFO. The /proc only returns the tunables |
69 | value of SEMMSL, SEMMNS, SEMOPM, and SEMMNI. |
70 | |
71 | The kernel also returns constant value for SEMVMX, SEMMNU, SEMMAP, SEMUME, |
72 | and also SEMUSZ and SEMAEM (for IPC_INFO). The issue to check them is they |
73 | might change over kernel releases. */ |
74 | |
75 | static void |
76 | read_sem_stat (struct test_seminfo *tseminfo) |
77 | { |
78 | FILE *f = fopen ("/proc/sys/kernel/sem" , "r" ); |
79 | if (f == NULL) |
80 | FAIL_UNSUPPORTED ("/proc is not mounted or /proc/sys/kernel/sem is not " |
81 | "available" ); |
82 | |
83 | int r = fscanf (stream: f, format: "%d %d %d %d" , |
84 | &tseminfo->semmsl, &tseminfo->semmns, &tseminfo->semopm, |
85 | &tseminfo->semmni); |
86 | TEST_VERIFY_EXIT (r == 4); |
87 | |
88 | fclose (f); |
89 | } |
90 | |
91 | |
92 | /* Check if the semaphore with IDX (index into the kernel's internal array) |
93 | matches the one with KEY. The CMD is either SEM_STAT or SEM_STAT_ANY. */ |
94 | |
95 | static bool |
96 | check_seminfo (int idx, key_t key, int cmd) |
97 | { |
98 | struct semid_ds seminfo; |
99 | int sid = semctl (semid: idx, semnum: 0, cmd: cmd, (union semun) { .buf = &seminfo }); |
100 | /* Ignore unused array slot returned by the kernel or information from |
101 | unknown semaphores. */ |
102 | if ((sid == -1 && errno == EINVAL) || sid != semid) |
103 | return false; |
104 | |
105 | if (sid == -1) |
106 | FAIL_EXIT1 ("semctl with SEM_STAT failed (errno=%d)" , errno); |
107 | |
108 | TEST_COMPARE (seminfo.sem_perm.__key, key); |
109 | TEST_COMPARE (seminfo.sem_perm.mode, SEM_MODE); |
110 | TEST_COMPARE (seminfo.sem_nsems, 1); |
111 | |
112 | return true; |
113 | } |
114 | |
115 | static int |
116 | do_test (void) |
117 | { |
118 | atexit (func: remove_sem); |
119 | |
120 | key_t key = ftok (pathname: name, proj_id: 'G'); |
121 | if (key == -1) |
122 | FAIL_EXIT1 ("ftok failed: %m" ); |
123 | |
124 | semid = semget (key: key, nsems: 1, IPC_CREAT | IPC_EXCL | SEM_MODE); |
125 | if (semid == -1) |
126 | FAIL_EXIT1 ("semget failed: %m" ); |
127 | |
128 | struct test_seminfo tipcinfo; |
129 | read_sem_stat (tseminfo: &tipcinfo); |
130 | |
131 | int semidx; |
132 | |
133 | { |
134 | struct seminfo ipcinfo; |
135 | semidx = semctl (semid: semid, semnum: 0, IPC_INFO, (union semun) { .__buf = &ipcinfo }); |
136 | if (semidx == -1) |
137 | FAIL_EXIT1 ("semctl with IPC_INFO failed: %m" ); |
138 | |
139 | TEST_COMPARE (ipcinfo.semmsl, tipcinfo.semmsl); |
140 | TEST_COMPARE (ipcinfo.semmns, tipcinfo.semmns); |
141 | TEST_COMPARE (ipcinfo.semopm, tipcinfo.semopm); |
142 | TEST_COMPARE (ipcinfo.semmni, tipcinfo.semmni); |
143 | } |
144 | |
145 | /* Same as before but with SEM_INFO. */ |
146 | { |
147 | struct seminfo ipcinfo; |
148 | semidx = semctl (semid: semid, semnum: 0, SEM_INFO, (union semun) { .__buf = &ipcinfo }); |
149 | if (semidx == -1) |
150 | FAIL_EXIT1 ("semctl with IPC_INFO failed: %m" ); |
151 | |
152 | TEST_COMPARE (ipcinfo.semmsl, tipcinfo.semmsl); |
153 | TEST_COMPARE (ipcinfo.semmns, tipcinfo.semmns); |
154 | TEST_COMPARE (ipcinfo.semopm, tipcinfo.semopm); |
155 | TEST_COMPARE (ipcinfo.semmni, tipcinfo.semmni); |
156 | } |
157 | |
158 | /* We check if the created semaphore shows in the system-wide status. */ |
159 | bool found = false; |
160 | for (int i = 0; i <= semidx; i++) |
161 | { |
162 | /* We can't tell apart if SEM_STAT_ANY is not supported (kernel older |
163 | than 4.17) or if the index used is invalid. So it just check if |
164 | value returned from a valid call matches the created semaphore. */ |
165 | check_seminfo (idx: i, key, SEM_STAT_ANY); |
166 | |
167 | if (check_seminfo (idx: i, key, SEM_STAT)) |
168 | { |
169 | found = true; |
170 | break; |
171 | } |
172 | } |
173 | |
174 | if (!found) |
175 | FAIL_EXIT1 ("semctl with SEM_STAT/SEM_STAT_ANY could not find the " |
176 | "created semaphore" ); |
177 | |
178 | if (semctl (semid: semid, semnum: 0, IPC_RMID, 0) == -1) |
179 | FAIL_EXIT1 ("semctl failed: %m" ); |
180 | |
181 | return 0; |
182 | } |
183 | |
184 | #include <support/test-driver.c> |
185 | |