Home | History | Annotate | Download | only in sysvipc 
      1 /* Copyright (c) 2014 Red Hat, Inc.
      2  *
      3  * This program is free software: you can redistribute it and/or modify
      4  * it under the terms of version 2 the GNU General Public License as
      5  * published by the Free Software Foundation.
      6  *
      7  * This program is distributed in the hope that it will be useful,
      8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     10  * GNU General Public License for more details.
     11  *
     12  * You should have received a copy of the GNU General Public License
     13  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
     14  ***********************************************************************
     15  * File: shm_comm.c
     16  *
     17  * Description:
     18  * 1. Clones two child processes with CLONE_NEWIPC flag, each child
     19  *    allocates System V shared memory segment (shm) with the _identical_
     20  *    key and attaches that segment into its address space.
     21  * 2. Child1 writes into the shared memory segment.
     22  * 3. Child2 writes into the shared memory segment.
     23  * 4. Writes to the shared memory segment with the identical key but from
     24  *    two different IPC namespaces should not interfere with each other
     25  *    and so child1 checks whether its shared segment wasn't changed
     26  *    by child2, if it wasn't test passes, otherwise test fails.
     27  */
     28 
     29 #define _GNU_SOURCE
     30 #include <sys/ipc.h>
     31 #include <sys/shm.h>
     32 #include <sys/types.h>
     33 #include <sys/wait.h>
     34 #include <stdio.h>
     35 #include <errno.h>
     36 #include "ipcns_helper.h"
     37 #include "test.h"
     38 #include "safe_macros.h"
     39 
     40 
     41 #define TESTKEY 124426L
     42 #define SHMSIZE 50
     43 char *TCID	= "shm_comm";
     44 int TST_TOTAL	= 1;
     45 
     46 static void cleanup(void)
     47 {
     48 	tst_rmdir();
     49 }
     50 
     51 static void setup(void)
     52 {
     53 	tst_require_root();
     54 	check_newipc();
     55 	tst_tmpdir();
     56 	TST_CHECKPOINT_INIT(tst_rmdir);
     57 }
     58 
     59 int chld1_shm(void *arg)
     60 {
     61 	int id, rval = 0;
     62 	char *shmem;
     63 
     64 	id = shmget(TESTKEY, SHMSIZE, IPC_CREAT);
     65 	if (id == -1) {
     66 		perror("shmget");
     67 		return 2;
     68 	}
     69 
     70 	if ((shmem = shmat(id, NULL, 0)) == (char *) -1) {
     71 		perror("shmat");
     72 		shmctl(id, IPC_RMID, NULL);
     73 		return 2;
     74 	}
     75 
     76 	*shmem = 'A';
     77 
     78 	TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 0);
     79 
     80 	/* if child1 shared segment has changed (by child2) report fail */
     81 	if (*shmem != 'A')
     82 		rval = 1;
     83 
     84 	/* tell child2 to continue */
     85 	TST_SAFE_CHECKPOINT_WAKE(NULL, 0);
     86 
     87 	shmdt(shmem);
     88 	shmctl(id, IPC_RMID, NULL);
     89 	return rval;
     90 }
     91 
     92 int chld2_shm(void *arg)
     93 {
     94 	int id;
     95 	char *shmem;
     96 
     97 	id = shmget(TESTKEY, SHMSIZE, IPC_CREAT);
     98 	if (id == -1) {
     99 		perror("shmget");
    100 		return 2;
    101 	}
    102 
    103 	if ((shmem = shmat(id, NULL, 0)) == (char *) -1) {
    104 		perror("shmat");
    105 		shmctl(id, IPC_RMID, NULL);
    106 		return 2;
    107 	}
    108 
    109 	/* wait for child1 to write to his segment */
    110 	TST_SAFE_CHECKPOINT_WAIT(NULL, 0);
    111 
    112 	*shmem = 'B';
    113 
    114 	TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 0);
    115 
    116 	shmdt(shmem);
    117 	shmctl(id, IPC_RMID, NULL);
    118 	return 0;
    119 }
    120 
    121 static void test(void)
    122 {
    123 	int status, ret = 0;
    124 
    125 	ret = do_clone_unshare_test(T_CLONE, CLONE_NEWIPC, chld1_shm, NULL);
    126 	if (ret == -1)
    127 		tst_brkm(TBROK | TERRNO, cleanup, "clone failed");
    128 
    129 	ret = do_clone_unshare_test(T_CLONE, CLONE_NEWIPC, chld2_shm, NULL);
    130 	if (ret == -1)
    131 		tst_brkm(TBROK | TERRNO, cleanup, "clone failed");
    132 
    133 
    134 	while (wait(&status) > 0) {
    135 		if (WIFEXITED(status) && WEXITSTATUS(status) == 1)
    136 			ret = 1;
    137 		if (WIFEXITED(status) && WEXITSTATUS(status) == 2)
    138 			tst_brkm(TBROK | TERRNO, cleanup, "error in child");
    139 		if (WIFSIGNALED(status)) {
    140 			tst_resm(TFAIL, "child was killed with signal %s",
    141 					tst_strsig(WTERMSIG(status)));
    142 			return;
    143 		}
    144 	}
    145 
    146 	if (ret)
    147 		tst_resm(TFAIL, "SysV shm: communication with identical keys"
    148 				" between namespaces");
    149 	else
    150 		tst_resm(TPASS, "SysV shm: communication with identical keys"
    151 				" between namespaces");
    152 }
    153 
    154 int main(int argc, char *argv[])
    155 {
    156 	int lc;
    157 
    158 	tst_parse_opts(argc, argv, NULL, NULL);
    159 
    160 	setup();
    161 
    162 	for (lc = 0; TEST_LOOPING(lc); lc++)
    163 		test();
    164 
    165 	cleanup();
    166 	tst_exit();
    167 }
    168