RFR: 8335664: Parsing jsr broken: assert(bci>= 0 && bci < c->method()->code_size()) failed: index out of bounds [v2]

[Dean Long]

On Wed, 21 Aug 2024 19:33:46 GMT, Matias Saavedra Silva <matsaave at openjdk.org> wrote:

>> Although JSR bytecodes cannot be generated by javac anymore, a classfile generated with a tool like JASM can still contain this bytecode. Should a program end with a JSR, there will be undefined behavior since the bytecode reads the address of the next instruction. In the case of Hotspot, this leads to a crash when generating oop maps. This fixes the calculation of basic blocks. 
>> 
>> The early exploration of this issue was done by @eme64 who also generated a reproducer.
>
> Matias Saavedra Silva has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Removed incorrect comment and added copyright
>  - Added regression test

test/hotspot/jtreg/runtime/interpreter/LastJsr.jasm line 32:

> 30:         return;
> 31:     LABEL:
> 32:         nop;

Are these NOP instructions in both tests necessary?

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PR Review Comment: https://git.openjdk.org/jdk/pull/20645#discussion_r1725661836