1 static key_t probe_key; 2 3 void *probe_free_addr(void) 4 { 5 void *p; 6 int ret; 7 int shm_id = -1; 8 9 if (probe_key == 0) 10 probe_key = getipckey(); 11 12 /* create a shared memory resource with read and write permissions 13 * We align this to SHMLBA so we should allocate at least 14 * SHMLBA*2 in case SHMLBA > page_size. */ 15 shm_id = shmget(probe_key, SHMLBA*2, SHM_RW | IPC_CREAT | IPC_EXCL); 16 if (shm_id == -1) 17 tst_brkm(TBROK, cleanup, "probe: shmget failed"); 18 19 /* Probe an available linear address for attachment */ 20 p = shmat(shm_id, NULL, 0); 21 if (p == (void *)-1) 22 tst_brkm(TBROK, cleanup, "probe: shmat failed"); 23 ret = shmdt(p); 24 if (ret == -1) 25 tst_brkm(TBROK, cleanup, "probe: shmdt failed"); 26 27 rm_shm(shm_id); 28 29 /* some architectures (e.g. parisc) are strange, so better always 30 * align to next SHMLBA address. */ 31 p = (void *)(((unsigned long)(p) + (SHMLBA - 1)) & ~(SHMLBA - 1)); 32 return p; 33 } 34
