/* Copyright (c) 2014 Red Hat, Inc. * * This program is free software: you can redistribute it and/or modify * it under the terms of version 2 the GNU General Public License as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. *********************************************************************** * File: shm_comm.c * * Description: * 1. Clones two child processes with CLONE_NEWIPC flag, each child * allocates System V shared memory segment (shm) with the _identical_ * key and attaches that segment into its address space. * 2. Child1 writes into the shared memory segment. * 3. Child2 writes into the shared memory segment. * 4. Writes to the shared memory segment with the identical key but from * two different IPC namespaces should not interfere with each other * and so child1 checks whether its shared segment wasn't changed * by child2, if it wasn't test passes, otherwise test fails. */ #define _GNU_SOURCE #include <sys/ipc.h> #include <sys/shm.h> #include <sys/types.h> #include <sys/wait.h> #include <stdio.h> #include <errno.h> #include "ipcns_helper.h" #include "test.h" #include "safe_macros.h" #define TESTKEY 124426L #define SHMSIZE 50 char *TCID = "shm_comm"; int TST_TOTAL = 1; static void cleanup(void) { tst_rmdir(); } static void setup(void) { tst_require_root(); check_newipc(); tst_tmpdir(); TST_CHECKPOINT_INIT(tst_rmdir); } int chld1_shm(void *arg) { int id, rval = 0; char *shmem; id = shmget(TESTKEY, SHMSIZE, IPC_CREAT); if (id == -1) { perror("shmget"); return 2; } if ((shmem = shmat(id, NULL, 0)) == (char *) -1) { perror("shmat"); shmctl(id, IPC_RMID, NULL); return 2; } *shmem = 'A'; TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 0); /* if child1 shared segment has changed (by child2) report fail */ if (*shmem != 'A') rval = 1; /* tell child2 to continue */ TST_SAFE_CHECKPOINT_WAKE(NULL, 0); shmdt(shmem); shmctl(id, IPC_RMID, NULL); return rval; } int chld2_shm(void *arg) { int id; char *shmem; id = shmget(TESTKEY, SHMSIZE, IPC_CREAT); if (id == -1) { perror("shmget"); return 2; } if ((shmem = shmat(id, NULL, 0)) == (char *) -1) { perror("shmat"); shmctl(id, IPC_RMID, NULL); return 2; } /* wait for child1 to write to his segment */ TST_SAFE_CHECKPOINT_WAIT(NULL, 0); *shmem = 'B'; TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 0); shmdt(shmem); shmctl(id, IPC_RMID, NULL); return 0; } static void test(void) { int status, ret = 0; ret = do_clone_unshare_test(T_CLONE, CLONE_NEWIPC, chld1_shm, NULL); if (ret == -1) tst_brkm(TBROK | TERRNO, cleanup, "clone failed"); ret = do_clone_unshare_test(T_CLONE, CLONE_NEWIPC, chld2_shm, NULL); if (ret == -1) tst_brkm(TBROK | TERRNO, cleanup, "clone failed"); while (wait(&status) > 0) { if (WIFEXITED(status) && WEXITSTATUS(status) == 1) ret = 1; if (WIFEXITED(status) && WEXITSTATUS(status) == 2) tst_brkm(TBROK | TERRNO, cleanup, "error in child"); if (WIFSIGNALED(status)) { tst_resm(TFAIL, "child was killed with signal %s", tst_strsig(WTERMSIG(status))); return; } } if (ret) tst_resm(TFAIL, "SysV shm: communication with identical keys" " between namespaces"); else tst_resm(TPASS, "SysV shm: communication with identical keys" " between namespaces"); } int main(int argc, char *argv[]) { int lc; tst_parse_opts(argc, argv, NULL, NULL); setup(); for (lc = 0; TEST_LOOPING(lc); lc++) test(); cleanup(); tst_exit(); }