Agree, it would be better to don't try to use data from functions with
error code. The new webrev:
http://cr.openjdk.java.net/~lmesnik/8242891/webrev.01/
I tried to prevent any usage of possibly corrupted data. Mostly strings
or allocated data, sometimes method/class id which are used my other
JVMTI functions.
Leonid
On 6/9/20 6:59 PM, serguei.spit...@oracle.com wrote:
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
