[jira] Closed: (HARMONY-4163) [drlvm][jvmti] GetLocalVariableTable() crashes due to misprint in Method::get_local_var_entry()

["Ivan Popov (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HARMONY-4163?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Ivan Popov closed HARMONY-4163.
-------------------------------


Thanks, Gregory. Verified in harmony-jdk-r547543. Closing this issue.


> [drlvm][jvmti] GetLocalVariableTable() crashes due to misprint in Method::get_local_var_entry()
> -----------------------------------------------------------------------------------------------
>
>                 Key: HARMONY-4163
>                 URL: https://issues.apache.org/jira/browse/HARMONY-4163
>             Project: Harmony
>          Issue Type: Bug
>          Components: DRLVM
>         Environment: Windows/x86, harmony-jdk-r547139
>            Reporter: Ivan Popov
>            Assignee: Gregory Shimansky
>         Attachments: drlvm_jvmti.patch
>
>
> Some failures of EUT tests (org.eclipse.jdt.core.tests.eval.DebugEvaluationTests) described in HARMONY-3282 are because of DRLVM crashes in JVMTI function GetLocalVariableTable(). Quick investigation revealed that the problem is in misprint in implementation of the function Method::get_local_var_entry() (file vmcore\src\class_support\Class_File_Loader.cpp line 1240):
> bool Method::get_local_var_entry(unsigned index, jlong* pc,
>                          jint* length, jint* slot, String** name,
>                          String** type, String** generic_type) {
>     if (_line_number_table && index < _local_vars_table->length) {
>       ^^^^^^^^^^^^^^^^^^^^^^^^^^
>         *pc = _local_vars_table->table[index].start_pc;
>         *length = _local_vars_table->table[index].length;
>         *slot = _local_vars_table->table[index].index;
>         *name = _local_vars_table->table[index].name;
>         *type = _local_vars_table->table[index].type;
>         *generic_type = _local_vars_table->table[index].generic_type;
>         return true;
>     } else {
>         return false;
>     }
> }
> In the first line this function incorrectly uses '_line_number_table' instead of '_local_vars_table'. 
> In this particular case '_line_number_table' is NULL and function does not set any data and returns false. However, calling function jvmtiGetLocalVariableTable() does not check returned result and uses uninitialized data (file jvmti_method.cpp, line 436):
> jvmtiError JNICALL
> jvmtiGetLocalVariableTable(jvmtiEnv* env,
>                            jmethodID method,
>                            jint* entry_count_ptr,
>                            jvmtiLocalVariableEntry** table_ptr)
> {
>    ...
>     for( index = 0; index < count; index++)
>     {
>         String *name, *type, *generic_type;
>         jvmtiLocalVariableEntry* entry = *table_ptr + index;
>         method_ptr->get_local_var_entry(index,
>             &(entry->start_location),
>             &(entry->length),
>             &(entry->slot),
>             &name, &type, &generic_type);  // <--- does not check for false result
>            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>         // allocate memory for name
>         len = get_utf8_length_of_8bit( (const uint8*)name->bytes, name->len);
>         result = _allocate( len + 1, (unsigned char**)&pointer );
>         if( result != JVMTI_ERROR_NONE ) {
>             return result;
>         }
>    ...
> }

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