[LTP] [PATCH v3] munlockall: add test case that verifies memory has been unlocked

[Dennis Brendel]

Hi Cyril,

On 3/6/24 16:26, Cyril Hrubis wrote:
> Hi!
>> +/*\
>> + * [Description]
>> + *
>> + * Verify that munlockall(2) unlocks all previously locked memory
>> + */
>>  
>> -char *TCID = "munlockall01";
>> -int TST_TOTAL = 1;
>> +#include <sys/mman.h>
>>  
>> -#if !defined(UCLINUX)
>> +#include "tst_test.h"
>>  
>> -int main(int ac, char **av)
>> +static void verify_munlockall(void)
>>  {
>> -	int lc;
>> -
>> -	tst_parse_opts(ac, av, NULL, NULL);
>> +	unsigned long size = 0;
>>  
>> -	setup();
>> +	SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %ld", &size);
>>  
>> -	/* check looping state */
>> -	for (lc = 0; TEST_LOOPING(lc); lc++) {
>> +	if (size != 0UL)
>> +		tst_brk(TBROK, "Locked memory after init should be 0 but is %ld", size);
>>  
>> -		tst_count = 0;
>> +	if (mlockall(MCL_CURRENT | MCL_FUTURE) != 0)
>> +		tst_brk(TBROK | TERRNO, "Could not lock memory using mlockall()");
>>  
>> -		TEST(munlockall());
>> +	SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %ld", &size);
>>  
>> -		/* check return code */
>> -		if (TEST_RETURN == -1) {
>> -			tst_resm(TFAIL | TTERRNO, "munlockall() Failed with"
>> -				 " return=%ld", TEST_RETURN);
>> -		} else {
>> -			tst_resm(TPASS, "munlockall() passed with"
>> -				 " return=%ld ", TEST_RETURN);
>> +	if (size == 0UL)
>> +		tst_brk(TBROK, "Locked memory after mlockall() should be greater than 0, "
>> +			       "but is %ld", size);
> 
> This line can be shorter:
> 
> 	tst_brk(TBROK, "After mlockall() locked memory should be >0");
> 
> We already checked that size is 0 so no need to print it.

Agreed :-)

>> -		}
>> -	}
>> +	if (munlockall() != 0)
>> +		tst_brk(TBROK | TERRNO, "Could not unlock memory using munlockall()");
> 
> We are testing the munlockall() syscall here so it would be better to
> use the TST_EXP_PASS() macro.

The actual purpose of the test was not checking the return value of the syscall
(wrapper), but the behavior as reported by the kernel through /proc - but fair
enough, it does not do any harm :-)

>> -	/* cleanup and exit */
>> -	cleanup();
>> -	tst_exit();
>> +	SAFE_FILE_LINES_SCANF("/proc/self/status", "VmLck: %ld", &size);
>>  
>> +	if (size != 0UL)
>> +		tst_res(TFAIL, "Locked memory after munlockall() should be 0 but is %ld", size);
>> +
>> +	else
>> +		tst_res(TPASS, "Memory successfully locked and unlocked");
>>  }
>>  
>> -#else
>> -
>> -int main(void)
>> -{
>> -	tst_resm(TINFO, "test is not available on uClinux");
>> -	tst_exit();
>> -}
>> -
>> -#endif /* if !defined(UCLINUX) */
>> -
>> -/* setup() - performs all ONE TIME setup for this test. */
>> -void setup(void)
>> -{
>> -	tst_require_root();
>> -
>> -	tst_sig(NOFORK, DEF_HANDLER, cleanup);
>> -
>> -	TEST_PAUSE;
>> -}
>> -
>> -/*
>> - * cleanup() - performs all ONE TIME cleanup for this test at
>> - *		completion or premature exit.
>> - */
>> -void cleanup(void)
>> -{
>> -}
>> +static struct tst_test test = {
>> +	.test_all = verify_munlockall,
>> +};
>> -- 
>> 2.44.0
>>
>>
>> -- 
>> Mailing list info: https://lists.linux.it/listinfo/ltp
>