[LTP] [PATCH v3] syscalls/add_key05: add maxbytes/maxkeys test under unprivileged user

[Yang Xu]

Hi Petr

> Hi Xu,
> 
>> This case is designed to test whether we can reach maxbytes/maxkeys
>> quota exactly under unprivileged users. It is a regression test for
>> commit a08bf91ce28e ("KEYS: allow reaching the keys quotas exactly").
>> But this kenrel commit is a incomplete fix, it still fails on lastest
> nit: typos: kenrel, lastest (will be fixed during merge).
>> upstream kernel. Fix patch[1] is on linux-next branch.
> 
>> [1]https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=2e356101e72a
> I guess this commit get's preserved when merged in mainline, so we don't have to
> wait for it.
This morning, I got email about this patch[1](change subject"keys: Fix 
the keys quotas limit check"). I'm not sure whether they will recycle 
and modify this.

[1]https://patchwork.kernel.org/patch/11411507/
> 
> Reviewed-by: Petr Vorel <pvorel@suse.cz>
> LGTM except one concern about ltpuser setup.
> 
>> +++ b/testcases/kernel/syscalls/add_key/add_key05.c
> ...
>> + * Test unprivileged user can support the number of keys and the
>> + * number of bytes consumed in payloads of the keys. The defalut
>> + * value is 200 and 20000.
>> + * This is also a regresstion test for
> nit: typos: defalut, regresstion (will be fixed during merge).
Sorry for these typos.
> 
>> + * commit a08bf91ce28e ("KEYS: allow reaching the keys quotas exactly")
>> + * commit 2e356101e72a ("KEYS: reaching the keys quotas correctly")
>> + */
> 
>> +struct passwd *ltpuser;
> ...
>> +static void add_user(void)
>> +{
>> +	if (user_added)
>> +		return;
>> +
>> +	const char *const cmd_useradd[] = {"useradd", username, NULL};
>> +	int rc;
>> +
>> +	switch ((rc = tst_run_cmd(cmd_useradd, NULL, NULL, 1))) {
>> +	case 0:
>> +		user_added = 1;
>> +		ltpuser = SAFE_GETPWNAM(username);
>> +		break;
>> +	case 1:
>> +	case 255:
>> +		break;
>> +	default:
>> +		tst_brk(TBROK, "Useradd failed (%d)", rc);
>> +	}
>> +	sprintf(fmt, "%5u: %%*5d %%*d/%%*d %%d/%%d %%d/%%d", ltpuser->pw_uid);
>> +}
> ltpuser is undefined for 1 and 255, therefore it gets SIGSEGV. It should either
> require tst_run_cmd to exit 0 or use 0 as UID (root UID).
Oh, sorry for this obvious mistake, thanks for pointing out it.
Yes, I prefer to exit when running into 0 or 255.

Best Regards
Yang Xu
> 
> Kind regards,
> Petr
> 
>