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

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

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.

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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