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

[Calvin Cheung]

Thanks Yumin.

Calvin

On 7/17/15 11:14 AM, Yumin Qi wrote:
> Calvin,
>
>   Looks good.
>
> Thanks
> Yumin
>
> On 7/16/2015 10:09 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
>>
>