jit: Fail to successfully execute the JIT assembler

[jserv]

xkon was tested with interpreter. However, JIT compiler fails to execute it successfully.
The way to reproduce:

$ build/rvemu build/jit-bf.elf

Its output:

Execute 5 times with JIT precompile using xkon.

+0x2a = <.L0B>
+0x6e = <.L0E>
+0x118 = <.L1B>
+0x15c = <.L1E>
Address OPcode  ------- Instruction --------------------------------------------
...
??;(f0?Iaddi sp,sp,-32	# c.addi sp,-32
Segmentation fault (core dumped)

[jserv]

QEMU (w/ TCG) fails to run jit-bf.elf either.

$ qemu-riscv32 jit-bf.elf
...
Execute 5 times with JIT precompile using xkon.
+0x2c = <.L0B>
+0x70 = <.L0E>
+0x11a = <.L1B>
+0x15e = <.L1E>
Segmentation fault (core dumped)

[qwe661234]

After applying the PR #175 patch, this testcase sometimes passes and sometimes fails due to an issue with the assert function in the file src/map.c. The same issue also happens in interpreter-only mode.

• error message

rv32emu: src/map.c:242: void rb_remove(map_t, map_node_t *): Assertion `nodep && nodep->node == node' failed.
Aborted (core dumped)

[jserv]

rv32emu: src/map.c:242: void rb_remove(map_t, map_node_t *): Assertion `nodep && nodep->node == node' failed.
Aborted (core dumped)

Can you use rr to debug the recording?

[TheCloudlet]

@qwe661234 can you provide the reproduction steps?

[qwe661234]

@qwe661234 can you provide the reproduction steps?

The repoduction way is

./build/rv32emu ./build/jit-bf.elf 

[jserv]

The repoduction way is

build/rv32emu build/jit-bf.elf 

This issue is more easily reproducible on x86-64 machines. However, when using the Aarch64 architecture, I haven't encountered this issue on both macOS and GNU/Linux. I am unsure if there is a hidden alignment issue or not.

[TheCloudlet]

I executed 30 times in Aarch64, and all executed properly.
I cannot reproduce the assertion since I have no x64 machines.

rv32emu: src/map.c:242: void rb_remove(map_t, map_node_t *): Assertion `nodep && nodep->node == node' failed.
Aborted (core dumped)

The assertion failure above means that we cannot find the to-be-removed target node in the map.
If I have the environment, I would set breakpoint in front of the to-be-removed target and use find() to confirm this.

[jserv]

I executed 30 times in Aarch64, and all executed properly. I cannot reproduce the assertion since I have no x64 machines.

Alternatively, check the tutorial Running x86_64-based containers on Mac computers with an Apple silicon processor.

[visitorckw]

I quickly reviewed the relevant code and thanks to @ypaskell 's mention, "The assertion failure above means that we cannot find the to-be-removed target node in the map". It led me to think that perhaps the issue in the rb_remove function, when searching for the node to delete, might be due to using node->data for comparison instead of node->key.

I conducted some simple tests on x86_64 Linux, and it appears that this correction can potentially resolve the problem. However, I haven't thoroughly reviewed other code related to the map. If I haven't misunderstood, I can make code adjustments later after my class and then send a pull request to correct this error.

[TheCloudlet]

Hi @visitorckw,

Thank you for your careful inspection.
I believe this is the root cause.
Can you test it out and submit a PR?

It's better to also modify the unit test to ensure this behavior is tested.

[visitorckw]

Thanks for your prompt response.
I'll conduct more testing, adjust the unit tests, and submit the PR later.