| 1 | /* |
| 2 | * Test shmat(NULL). |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-or-later |
| 5 | */ |
| 6 | #include <assert.h> |
| 7 | #include <stdlib.h> |
| 8 | #include <sys/ipc.h> |
| 9 | #include <sys/shm.h> |
| 10 | |
| 11 | int main(void) |
| 12 | { |
| 13 | int shmid; |
| 14 | char *p; |
| 15 | int err; |
| 16 | |
| 17 | /* Create, attach and intialize shared memory. */ |
| 18 | shmid = shmget(IPC_PRIVATE, 1, IPC_CREAT | 0600); |
| 19 | assert(shmid != -1); |
| 20 | p = shmat(shmid, NULL, 0); |
| 21 | assert(p != (void *)-1); |
| 22 | *p = 42; |
| 23 | |
| 24 | /* Reattach, check that the value is still there. */ |
| 25 | err = shmdt(p); |
| 26 | assert(err == 0); |
| 27 | p = shmat(shmid, NULL, 0); |
| 28 | assert(p != (void *)-1); |
| 29 | assert(*p == 42); |
| 30 | |
| 31 | /* Detach. */ |
| 32 | err = shmdt(p); |
| 33 | assert(err == 0); |
| 34 | err = shmctl(shmid, IPC_RMID, NULL); |
| 35 | assert(err == 0); |
| 36 | |
| 37 | return EXIT_SUCCESS; |
| 38 | } |