RFR: 8207025: JvmtiEnv::SetSystemProperty() does not handle OOM [v2]

[David Holmes]

On Mon, 28 Mar 2022 18:34:31 GMT, Ioi Lam <iklam at openjdk.org> wrote:

>> `JvmtiEnv::SetSystemProperty` eventually calls `PathString::set_value` in arguments.cpp, which aborts the VM when it fails to allocate a string copy of the property value.
>> 
>> 
>> bool PathString::set_value(const char *value) {
>>   if (_value != NULL) {
>>     FreeHeap(_value);
>>   }
>>   _value = AllocateHeap(strlen(value)+1, mtArguments   );
>>   // should pass AllocFailStrategy::RETURN_NULL -----^
>>   assert(_value != NULL, "Unable to allocate space for new path value");
>> 
>> 
>> This should be fixed so that `JvmtiEnv::SetSystemProperty` can return `JVMTI_ERROR_OUT_OF_MEMORY` in case of OOM. See https://docs.oracle.com/en/java/javase/17/docs/specs/jvmti.html#SetSystemProperty
>
> Ioi Lam has updated the pull request incrementally with one additional commit since the last revision:
> 
>   @dholmes-ora comments: changed implementation to work with JvmtiEnv::SetSystemProperty

Hi Ioi,

I don't think this needs to be that complicated. In set_system_property you can query if the flag is writeable() directly, so then you don't need a ternary return value from set_property_value().

Also see comment below.

David

src/hotspot/share/prims/jvmtiEnv.cpp line 3431:

> 3429: jvmtiError
> 3430: JvmtiEnv::SetSystemProperty(const char* property, const char* value_ptr) {
> 3431:   NULL_CHECK(property, JVMTI_ERROR_NULL_POINTER);

You don't need this. The null check happens in the wrapper code generated from the xml file. See  build/<config>/hotspot/variant-server/gensrc/jvmtifiles/jvmtiEnterTrace.cpp

-------------

Changes requested by dholmes (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/7981