[LTP] [PATCH] shmget03: fix test when some shm segments already exist

[Alexey Kodanev]

On 06.07.2021 16:43, Alexey Kodanev wrote:
> Hi Li,
> On 06.07.2021 15:49, Li Wang wrote:
>> Hi Alexey,
>>
>> On Tue, Jul 6, 2021 at 6:59 PM Alexey Kodanev <aleksei.kodanev@bell-sw.com <mailto:aleksei.kodanev@bell-sw.com>> wrote:
>>
>>     It's unlikely, but still possible that some of them could be
>>     created during the test as well, so the patch only checks
>>     errno.
>>
>>
>> Thanks for fixing this, seems the msgget03 has this problem as well.
>> https://github.com/linux-test-project/ltp/issues/842 <https://github.com/linux-test-project/ltp/issues/842>
> 
> Yes, it is the same, it can be easily reproduced:
> 
> $ ./msgget03
> tst_test.c:1311: TINFO: Timeout per run is 0h 05m 00s
> msgget03.c:50: TINFO: The maximum number of message queues (32000) reached
> msgget03.c:29: TPASS: msgget(1627491660, 1536) : ENOSPC (28)
> 
> $ ipcmk -Q
> Message queue id: 32768
> 
> $ ./msgget03
> tst_test.c:1311: TINFO: Timeout per run is 0h 05m 00s
> msgget03.c:46: TBROK: msgget failed unexpectedly: ENOSPC (28)
> 
> 
> We can fix it similarly.
> 

It's also possible that some resources will be freed during
the tests... perhaps, moving the loop to verify_*() is the
better option?

diff --git a/testcases/kernel/syscalls/ipc/msgget/msgget03.c b/testcases/kernel/syscalls/ipc/msgget/msgget03.c
index 76cf82cd3..5b760b1d6 100644
--- a/testcases/kernel/syscalls/ipc/msgget/msgget03.c
+++ b/testcases/kernel/syscalls/ipc/msgget/msgget03.c
@@ -26,29 +26,29 @@ static key_t msgkey;

 static void verify_msgget(void)
 {
-       TST_EXP_FAIL2(msgget(msgkey + maxmsgs, IPC_CREAT | IPC_EXCL), ENOSPC,
-               "msgget(%i, %i)", msgkey + maxmsgs, IPC_CREAT | IPC_EXCL);
+       int num, res;
+
+       for (num = 0; num <= maxmsgs; ++num) {
+               res = msgget(msgkey + num, IPC_CREAT | IPC_EXCL);
+               if (res == -1) {
+                       if (errno == ENOSPC) {
+                               tst_res(TPASS | TERRNO, "created queues %d", num);
+                               return;
+                       }
+                       tst_brk(TFAIL | TERRNO,
+                               "msgget failed unexpectedly, num %d", num);
+               }
+               queues[queue_cnt++] = res;
+       }
 }
...