Stream: git-wasmtime

Topic: wasmtime / issue #7235 Different runtime results while ex...

Wasmtime GitHub notifications bot (Oct 13 2023 at 09:00):

luxinyi0105 added the bug label to Issue #7235.

Wasmtime GitHub notifications bot (Oct 13 2023 at 09:00):

luxinyi0105 opened issue #7235:

Describe the bug

While executing the given testcase with wasmtime and other runtime tools, the result are different.

Test Case

The given testcase was simply mutated a wasm file, which was obtained by compiling C program generated with Csmith using Emscripten Compiler(Emcc).

The original C program is c_file.c, the compilation results with Emscripten is wasm_file.wasm, and its wat format is wat_file.wat.

We mutated the wat file to:
-- change all its i32/i64/f64.sub with i32/i64/f64.add;
-- change all its i32/i64.and with i32/i64.xor;
-- change all its i32/i64.lt_s with i32/i64.ge_u;
-- change all its i32/i64.mul with i32/i64.div_u/div_s;
The result after mutation is mutated_file.wat, and its wasm format is mutated_file.wasm.

Actual Results

$ ~/Wasm_Runtime_Tools/wasmtime_13.0.0/target/debug/wasmtime mutated_file.wasm
Error: failed to run main module `mutated_file.wasm`

Caused by:
    0: failed to invoke command default
    1: error while executing at wasm backtrace:
           0: 0xb52e - <unknown>!<wasm function 67>
           1: 0xb4b8 - <unknown>!<wasm function 66>
    2: Pointer not aligned to 4: Region { start: 65527, len: 4 }

Expected Results

I tried to use other runtime tools, such as wasmer, wasmedge, and wamr to run the same testcase, their running results are as follows:


From the picture, we can see that tools like wasmer and wasmedge will output runtime error due to integer divide by zero. I wonder whether wasmtime should also output the same runtime error, and when there are multiple errors in the testcase, what the priority of runtime error output in the terminal is.

Versions and Environment

Wasmtime version or commit: wasmtime-cli 13.0.0
Operating system: Ubuntu 22.04.1
Architecture: x86_64

Wasmtime GitHub notifications bot (Oct 13 2023 at 12:29):

bjorn3 commented on issue #7235:

Wasmtime outputs "Pointer not aligned to 4". According to wasi pointers need to be aligned and wasmtime checks for this. Several other wasi implementations don't check for it however and thus hits the "integer divide by zero" at a later point.

Wasmtime GitHub notifications bot (Oct 13 2023 at 17:08):

pchickey commented on issue #7235:

This is the exact same behavior we closed as not a bug in https://github.com/bytecodealliance/wasmtime/issues/7081. This issue is also filed using the exact same language. Because these issues take more of our time to triage than they take for you to file, please try to filter out these duplicates on your end so that we can spend our attention on valid issues.

Wasmtime GitHub notifications bot (Oct 13 2023 at 17:08):

pchickey closed issue #7235:

Describe the bug

While executing the given testcase with wasmtime and other runtime tools, the result are different.

Test Case

The given testcase was simply mutated a wasm file, which was obtained by compiling C program generated with Csmith using Emscripten Compiler(Emcc).

The original C program is c_file.c, the compilation results with Emscripten is wasm_file.wasm, and its wat format is wat_file.wat.

We mutated the wat file to:
-- change all its i32/i64/f64.sub with i32/i64/f64.add;
-- change all its i32/i64.and with i32/i64.xor;
-- change all its i32/i64.lt_s with i32/i64.ge_u;
-- change all its i32/i64.mul with i32/i64.div_u/div_s;
The result after mutation is mutated_file.wat, and its wasm format is mutated_file.wasm.

Actual Results

$ ~/Wasm_Runtime_Tools/wasmtime_13.0.0/target/debug/wasmtime mutated_file.wasm
Error: failed to run main module `mutated_file.wasm`

Caused by:
    0: failed to invoke command default
    1: error while executing at wasm backtrace:
           0: 0xb52e - <unknown>!<wasm function 67>
           1: 0xb4b8 - <unknown>!<wasm function 66>
    2: Pointer not aligned to 4: Region { start: 65527, len: 4 }

Expected Results

I tried to use other runtime tools, such as wasmer, wasmedge, and wamr to run the same testcase, their running results are as follows:


From the picture, we can see that tools like wasmer and wasmedge will output runtime error due to integer divide by zero. I wonder whether wasmtime should also output the same runtime error, and when there are multiple errors in the testcase, what the priority of runtime error output in the terminal is.

Versions and Environment

Wasmtime version or commit: wasmtime-cli 13.0.0
Operating system: Ubuntu 22.04.1
Architecture: x86_64

Last updated: Nov 22 2024 at 16:03 UTC