RFR: 8331854: ubsan: copy.hpp:218:10: runtime error: addition of unsigned offset to 0x7fc2b4024518 overflowed to 0x7fc2b4024510

[Albert Mingkun Yang]

On Tue, 4 Jun 2024 14:11:42 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

> When building with ubsan, we see a number of overflows at this code location :
> 
> /jdk/src/hotspot/share/utilities/copy.hpp:218:10: runtime error: addition of unsigned offset to 0x7fc2b4024518 overflowed to 0x7fc2b4024510
>     #0 0x10b70896d in Copy::conjoint_words_to_higher(HeapWordImpl* const*, HeapWordImpl**, unsigned long) copy.hpp:218
>     #1 0x10c4f78f1 in Node_Array::insert(unsigned int, Node*) node.cpp:2783
>     #2 0x10b8a1386 in Block::insert_node(Node*, unsigned int) block.hpp:134
>     #3 0x10c556630 in PhaseOutput::fill_buffer(C2_MacroAssembler*, unsigned int*) output.cpp:1792
>     #4 0x10c552f6b in PhaseOutput::Output() output.cpp:367
>     #5 0x10b9ba859 in Compile::Code_Gen() compile.cpp:3035
>     #6 0x10b9b7cb1 in Compile::Compile(ciEnv*, ciMethod*, int, Options, DirectiveSet*) compile.cpp:896
>     #7 0x10b859912 in C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*) c2compiler.cpp:142
>     #8 0x10b9dd4f1 in CompileBroker::invoke_compiler_on_method(CompileTask*) compileBroker.cpp:2305
>     #9 0x10b9dc345 in CompileBroker::compiler_thread_loop() compileBroker.cpp:1963
>     #10 0x10bfd5ebf in JavaThread::thread_main_inner() javaThread.cpp:760
>     #11 0x10bfd5b62 in JavaThread::run() javaThread.cpp:745
>     #12 0x10c9310d6 in Thread::call_run() thread.cpp:221
>     #13 0x10c53ece4 in thread_native_entry(Thread*) os_bsd.cpp:598

I wonder if using for-loop works here. (Since #iterations is known, for-loop seems more natural.)


  for (size_t i = 0; i < count; ++i) {
    to[count - 1 - i] = from[count - 1 - i];
  }

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PR Comment: https://git.openjdk.org/jdk/pull/19541#issuecomment-2148428451