[LTP] [PATCH 3/3] syscalls/shmat03.c: add new regression test

[Xiao Yang <yangx.jy@cn.fujitsu.com>]

On 2017/06/22 18:09, Xiao Yang wrote:
> On 2017/06/01 19:53, Xiao Yang wrote:
>> On 2017/05/29 22:57, Cyril Hrubis wrote:
>>> Hi!
>>>> +    addr = shmat(shm_id, LOCATION, SHM_RND);
>>>> +    if (addr != (void *)-1)
>>>> +        tst_res(TINFO, "shmat() attached a nil-page unexpectedly");
>>>> +    else
>>>> +        tst_res(TINFO, "shmat() didn't attach a nil-page");
>>>> +
>>>> +    ((char *)addr)[0] = 'A';
>>>
>>> So if shmat() fails we try to write to (char*)-1 address, that does not
>>> sound right. Why don't we exit the test with TPASS in that case and 
>>> skip
>>> the part that tries to write to invalid address?
>>>
>>> Or at least dereference NULL here instead of the address returned from
>>> shmat() since that is guaranteed to SEGFAULT.
>> Hi Cyril
>>
>> I failed to call shmat() as root and returned EACCES if selinux is 
>> Enforcing.
>> Do you know how to fix this problem?
> Hi Cyril
>
> Sorry, I have fixed this issue, I will send v3 patch soon.
Hi Cyril and jan

Sorry， i tried to fix this issue， but failed.  Could you help me to 
look into it? Thanks a lot! :-(
shmat（） only attached a nil-page as root when selinux is not Enforcing.

Thanks,
Xiao Yang.
>
> Thanks,
> Xiao Yang.
>>
>> Thanks,
>> Xiao Yang.
>>>> +    tst_res(TINFO, "shmat() wrote data to shmaddr:%p 
>>>> unexpectedly", addr);
>>>> +
>>>> +    SAFE_SHMDT(addr);
>>>> +
>>>> +    exit(0);
>>>> +}
>>>> +
>>>> +static void do_shmat(unsigned int n)
>>>> +{
>>>> +    pid_t pid;
>>>> +    int status;
>>>> +    struct tcase *tc =&tcases[n];
>>>> +
>>>> +    pid = SAFE_FORK();
>>>> +    if (!pid)
>>>> +        verify_shmat(tc->exp_usr);
>>>> +
>>>> +    SAFE_WAITPID(pid,&status, 0);
>>>> +
>>>> +    if (WIFEXITED(status)) {
>>>> +        tst_res(TFAIL, "%s mapped nil-page in shmat() unexpectedly",
>>>> +            tc->des);
>>>> +        return;
>>>> +    }
>>>> +
>>>> +    if (WIFSIGNALED(status)&&  WTERMSIG(status) == SIGSEGV) {
>>>> +        tst_res(TPASS, "%s didn't map nil-page in shmat(), and was "
>>>> +            "killed by %s as expected", tc->des,
>>>> +            tst_strsig(WTERMSIG(status)));
>>>> +    } else {
>>>> +        tst_res(TFAIL, "%s didn't map nil-page in shmat(), and was "
>>>> +            "killed by %s unexpectedly", tc->des,
>>>> +            tst_strsig(WTERMSIG(status)));
>>>> +    }
>>>> +}
>>>> +
>>>> +static void setup(void)
>>>> +{
>>>> +    key_t shm_key;
>>>> +
>>>> +    shm_key = GETIPCKEY();
>>>> +    shm_id = SAFE_SHMGET(shm_key, 4096, 0777 | IPC_CREAT);
>>>> +}
>>>> +
>>>> +static void cleanup(void)
>>>> +{
>>>> +    if (shm_id != -1)
>>>> +        SAFE_SHMCTL(shm_id, IPC_RMID, NULL);
>>>> +}
>>>> +
>>>> +static struct tst_test test = {
>>>> +    .tid = "shmat03",
>>>> +    .needs_root = 1,
>>>> +    .forks_child = 1,
>>>> +    .test = do_shmat,
>>>> +    .tcnt = ARRAY_SIZE(tcases),
>>>> +    .setup = setup,
>>>> +    .cleanup = cleanup
>>>> +};
>>>> -- 
>>>> 1.8.3.1
>>>>
>>>>
>>>>
>>>>
>>>> -- 
>>>> Mailing list info: https://lists.linux.it/listinfo/ltp
>>
>>
>>
>>
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