Re: RFR: 8242891: vmTestbase/nsk/jvmti/ test should be fixed to fail early if JVMTI function return error

[serguei.spit...@oracle.com]

On 6/9/20 12:58, Leonid Mesnik wrote:

Hi

On 6/9/20 12:34 PM, serguei.spit...@oracle.com wrote:

Hi Leonid,

Thank you for taking care about this!
It looks good in general.
However, I think, a similar return is needed in more cases.

One example:

http://cr.openjdk.java.net/~lmesnik/8242891/webrev.00/test/hotspot/jtreg/vmTestbase/nsk/jvmti/Exception/exception001/exception001.cpp.frames.html

 99     err = jvmti_env->GetMethodDeclaringClass(method, &cls);
 100     if (err != JVMTI_ERROR_NONE) {
 101         printf("(GetMethodDeclaringClass#t) unexpected error: %s (%d)\n",
 102                TranslateError(err), err);
 103         result = STATUS_FAILED;
 104         return;
 105     }
 106     err = jvmti_env->GetClassSignature(cls, &ex.t_cls, &generic);
 107     if (err != JVMTI_ERROR_NONE) {
 108         printf("(GetClassSignature#t) unexpected error: %s (%d)\n",
 109                TranslateError(err), err);
 110         result = STATUS_FAILED;
 111     }
 112     err = jvmti_env->GetMethodName(method,
 113         &ex.t_name, &ex.t_sig, &generic);
 114     if (err != JVMTI_ERROR_NONE) {
 115         printf("(GetMethodName#t) unexpected error: %s (%d)\n",
 116                TranslateError(err), err);
 117         result = STATUS_FAILED;
 118     }
 119     ex.t_loc = location;
 120     err = jvmti_env->GetMethodDeclaringClass(catch_method, &cls);
 121     if (err != JVMTI_ERROR_NONE) {
 122         printf("(GetMethodDeclaringClass#c) unexpected error: %s (%d)\n",
 123                TranslateError(err), err);
 124         result = STATUS_FAILED;
 125         return;
 126     }
 127     err = jvmti_env->GetClassSignature(cls, &ex.c_cls, &generic);
 128     if (err != JVMTI_ERROR_NONE) {
 129         printf("(GetClassSignature#c) unexpected error: %s (%d)\n",
 130                TranslateError(err), err);
 131         result = STATUS_FAILED;
 132     }
 133     err = jvmti_env->GetMethodName(catch_method,
 134         &ex.c_name, &ex.c_sig, &generic);
 135     if (err != JVMTI_ERROR_NONE) {
 136         printf("(GetMethodName#c) unexpected error: %s (%d)\n",
 137                TranslateError(err), err);
 138         result = STATUS_FAILED;
 139     }

In the fragment above you added return for JVMTI GetMethodDeclaringClass error.
But GetMethodName and GetClassSignature can be also problematic as the returned names are printed below.
It seems to be more safe and even simpler to add returns for such cases as well.
Otherwise, the code reader is puzzled why there is a return in one failure case and there is no such return in another.

It is a good question if we want to fix such places or even fails with first JVMTI failure. (I even started to fix it in the such way but find that existing tests usually don't fail always).

I do not suggest to fix all the tests but those which you are already fixing.

The difference is that test tries to reuse "cls" in other JVMTI function and going to generate very misleading crash. How it just tries to compare ex and exs values. So test might crash but clearly outside of JVMTI function and with some useful info. So I am not sure if fixing these lines improve test failure handling.

If JVMTI functions fail with an error code the results with symbolic strings must be considered invalid.
However, they are used later (the values are printed).
It is better to bail out in such cases.
It should not be a problem to add similar returns in such cases.
Or do you think it is important to continue execution for some reason?

Assuming that most of existing tests fails early only if going to re-use possible corrupted data I propose to fix this separately. We need to figure out when to fail or to try to finish.

Do you suggest it for the updated tests only or for all the tests with such problems?

Thanks,
Serguei

Leonid

Thanks,
Serguei


On 6/1/20 21:33, Leonid Mesnik wrote:

Hi

Could you please review following fix which stop test execution if JVMTI function returns error. The test fails anyway however using potentially bad data in JVMTI function might cause misleading crash failures. The hs_err will contains the stacktrace not with problem function but with function called with corrupted data. Most of tests already has such behavior but not all. Also I fixed a couple of tests to finish if they haven't managed to suspend thread.

I've updated only tests which try to use corrupted data in JVMTI functions after errors. I haven't updated tests which just compare/print values from erroring JVMTI functions. The crash in strcmp/println is not so misleading and might be point to real issue.

webrev: http://cr.openjdk.java.net/~lmesnik/8242891/webrev.00/

bug: https://bugs.openjdk.java.net/browse/JDK-8242891

Leonid