RFR(XS): 8079825: Uninitialised variable in hotspot/src/share/vm & cpu/x86/vm (runtime)

[Calvin Cheung]

Thanks for your review, David.

Calvin

On 7/16/15 7:56 PM, David Holmes wrote:
> Looks good Calvin!
>
> Thanks,
> David
>
> On 17/07/2015 3:09 AM, Calvin Cheung wrote:
>> This is for fixing some warnings about uninitialized variables reported
>> by our internal code analysis tool.
>>
>> JBS: https://bugs.openjdk.java.net/browse/JDK-8079825
>>        (this is a confidential bug)
>>
>> webrev: http://cr.openjdk.java.net/~ccheung/8079825/webrev.00/
>>
>> [1] Uninitialised pointer localvariable_type_table_start may be used as
>> argument
>> 8 when calling ClassFileParser::copy_localvariable_table at line 2465 of
>> hotspot/src/share/vm/classfile/classFileParser.cpp in function
>> ClassFileParser::parse_method
>>
>> Similar warning message for the other 3 local variables.
>>
>> The fix in classFileParser.cpp is for initializing the following
>> variables to NULL:
>>      localvariable_table_length,
>>      localvariable_table_start,
>>      localvariable_type_table_length,
>>      localvariable_type_table_start
>>
>> They may not be defined if the execution path goes through the if block
>> at line 2137:
>>          if (LoadLineNumberTables &&
>>              _cp->symbol_at(code_attribute_name_index) ==
>> vmSymbols::tag_line_number_table()) {
>>            // Parse and compress line number table
>>            parse_linenumber_table(code_attribute_length, code_length,
>>              &linenumber_table, CHECK_(nullHandle));
>>
>> [2] Uninitialised pointer rf may be used as argument 1 when calling
>> RFrame::set_distance at line 96 of
>> hotspot/src/share/vm/runtime/rframe.cpp in
>> function RFrame::new_RFrame
>>
>> The fix in rframe.cpp is for initializing the rf to NULL.
>>
>> It isn't being initialized if the execution path goes to the else block:
>>      } else {
>>        assert(false, "Unhandled frame type");
>>      }
>>
>> the assert is only for debug build.
>>
>> Testing:
>>     JPRT
>>    Aurora adhoc run including vm.quick on linux, windows (32- and
>> 64-bit), and solaris sparc and x64
>>
>> Thanks in advance for your review.
>>
>> Calvin
>>