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

[Matthias Baesken]

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

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Commit messages:
 - JDK-8331854

Changes: https://git.openjdk.org/jdk/pull/19541/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19541&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8331854
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/19541.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19541/head:pull/19541

PR: https://git.openjdk.org/jdk/pull/19541