fix(wasix): report /dev/null as a character device

[artemyarulin]

Fix WASIX /dev/null metadata so it stats as a character device instead of a regular file.

Previously, /dev/null behaved like a null device for I/O, but stat()/fstat() reported it as a regular file.

[Arshia001]

See comments.

[Arshia001]

This check is way too broad. Off the top of my head, nothing prevents wasix apps from creating normal files in /dev, and this also creates real chances for regressions if we add more things to /dev from the host side.

[artemyarulin]

Shield - Regression 💩💩💩

Language	Tests	Pass rate now	PASS	FAIL	TIMEOUT	CRASH
Python	37,965	74.4%	$${\color{green}+5}$$	$${\color{red}+14}$$	$${\color{green}-24}$$	0
Node.js	5,094	19.9%	$${\color{green}+3}$$	$${\color{green}-19}$$	$${\color{red}+44}$$	$${\color{green}-31}$$
PHP	19,917	72.2%	$${\color{green}+3}$$	$${\color{green}-3}$$	0	$${\color{green}-1}$$
Rust	24,084	86.4%	$${\color{red}-1}$$	$${\color{red}+41}$$	0	$${\color{red}+3}$$

Example crash from Python

• Repro command: shield run --lang python --wasmer [WASMER BINARY] test.test_os
• Full status file: [tests_python_results.json](https://github.com/wasmerio/compat-tests/blob/ 8 files changed, 289 insertions(+), 318 deletions(-)/tests_python_results.json)

crash: test_dup2_negative_fd (test.test_os.TestInvalidFD.test_dup2_negative_fd) ... memory allocation of 274877906944 bytes failed
stack backtrace:
   0:     0x55a4cf3065c2 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::hdadc7c28d26d7ce3
   1:     0x55a4cf31af5a - core::fmt::write::h469843d235cc4241
   2:     0x55a4cf2c8986 - std::io::Write::write_fmt::h384251ddb7f1467c
   3:     0x55a4cf2dbc6e - std::alloc::default_alloc_error_hook::h4f14f7c42c459bc4
   4:     0x55a4cf2dbd16 - std::alloc::rust_oom::{{closure}}::he56f046becd6482a
   5:     0x55a4cf2d9229 - std::sys::backtrace::__rust_end_short_backtrace::hb92aa0636159dd89
   6:     0x55a4cf2dbcea - std::alloc::rust_oom::h5e12a122d00da65c
   7:     0x55a4cf2bb953 - __rustc[16f1505adc47261a]::__rust_alloc_error_handler
   8:     0x55a4cf315bbc - alloc::alloc::handle_alloc_error::h9898627cde6f100a
   9:     0x55a4cf315fa9 - alloc::raw_vec::handle_error::hfa86a3a4628bd209
  10:     0x55a4caa8cace - alloc::raw_vec::RawVecInner<A>::reserve::do_reserve_and_handle::hbeffd85500228655
  11:     0x55a4cad17105 - alloc::vec::Vec<T,A>::resize::h09faf9851c6ccd86
  12:     0x55a4cad2c476 - wasmer_wasix::fs::fd_list::FdList::insert::h3ab3929d3b968dcf
  13:     0x55a4caee5c36 - wasmer_wasix::syscalls::wasi::fd_renumber::fd_renumber_internal::h5a911812959accb4
  14:     0x55a4caee4e6d - wasmer_wasix::syscalls::wasi::fd_renumber::fd_renumber::hbafa196b9679046d
  15:     0x55a4cae410c4 - corosensei::coroutine::on_stack::wrapper::h91dea9655da508cf
  16:     0x55a4ce8a4169 - stack_call_trampoline
  17:     0x55a4cacb2f4e - wasmer_vm::trap::traphandlers::on_host_stack::h45464539e3601cb5
  18:     0x55a4caba65cb - wasmer::backend::sys::entities::function::gen_fn_callback_s2::func_wrapper::h980a0191116fcbec
  19:     0x7f9d1f3acb6d - <unknown>
  20:     0x7f9d1f3ab68e - <unknown>
  21:     0x7f9d1fc2b6a0 - <unknown>
  22:     0x7f9d1f783129 - <unknown>
  23:     0x7f9d1f61b4d2 - <unknown>
  24:     0x7f9d1f71194b - <unknown>
  25:     0x7f9d1f6c5b20 - <unknown>
  26:     0x7f9d1f6c59c4 - <unknown>
  27:     0x7f9d1f6cc75e - <unknown>
  28:     0x7f9d1f6c5728 - <unknown>
  29:     0x7f9d1f6c5891 - <unknown>
  30:     0x7f9d1f70cd91 - <unknown>
  31:     0x7f9d1f6c5b20 - <unknown>
  32:     0x7f9d1f6c59c4 - <unknown>
  33:     0x7f9d1f6c4b17 - <unknown>
  34:     0x7f9d1f6c5f16 - <unknown>
  35:     0x7f9d1f7d8b92 - <unknown>
  36:     0x7f9d1f6c4537 - <unknown>
  37:     0x7f9d1f684974 - <unknown>

Example crash from Node.js

• Repro command: shield run --lang node --wasmer [WASMER BINARY] async-hooks/test-async-exec-resource-http-32060.js
• Full status file: [tests_node_results.json](https://github.com/wasmerio/compat-tests/blob/ 8 files changed, 289 insertions(+), 318 deletions(-)/tests_node_results.json)

crash:     /home/runner/work/anti-regression-shield/anti-regression-shield/.work/node/node-wrapper-bf1d279c94374dc4.sh: line 12: 64865 Segmentation fault      (core dumped) '/home/runner/work/anti-regression-shield/anti-regression-shield/.work/wasmer/checkout/target/release/wasmer' run --registry 'wasmer.io' --net '--experimental-napi' --volume '/home/runner/work/anti-regression-shield/anti-regression-shield/.work/node/checkout:/home/runner/work/anti-regression-shield/anti-regression-shield/.work/node/checkout' 'wasmer/edgejs' -- "$@"

Example crash from PHP

• Repro command: shield run --lang php --wasmer [WASMER BINARY] php-batch-0316
• Full status file: [tests_php_results.json](https://github.com/wasmerio/compat-tests/blob/ 8 files changed, 289 insertions(+), 318 deletions(-)/tests_php_results.json)

crash: thread 'TokioTaskManager Thread Pool_thread_6' (27549) panicked at lib/wasix/src/syscalls/wasi/path_rename.rs:285:10:
Expected target inode to exist, and it's too late to safely fail: Errno::noent
stack backtrace:
   0:     0x55f0009505c2 - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::hdadc7c28d26d7ce3
   1:     0x55f000964f5a - core::fmt::write::h469843d235cc4241
   2:     0x55f000912986 - std::io::Write::write_fmt::h384251ddb7f1467c
   3:     0x55f000929f09 - std::panicking::default_hook::{{closure}}::hd9d92b9a46805102
   4:     0x55f000929d69 - std::panicking::default_hook::hedb2be0819bbe276
   5:     0x55f00092a1fb - std::panicking::panic_with_hook::h0fc23abecf35c6bd
   6:     0x55f000929fc8 - std::panicking::panic_handler::{{closure}}::ha111c1a3ccf85d19
   7:     0x55f000923209 - std::sys::backtrace::__rust_end_short_backtrace::h41d63216e1ba5fa4
   8:     0x55f00090577d - __rustc[16f1505adc47261a]::rust_begin_unwind
   9:     0x55f00097066c - core::panicking::panic_fmt::hc13412975f563dde
  10:     0x55f00096f822 - core::result::unwrap_failed::hd8abf8e6faab58b4
  11:     0x55effc17e201 - wasmer_wasix::syscalls::wasi::path_rename::path_rename_internal::hbc0fbfdc4d3d9177
  12:     0x55effc17aca3 - wasmer_wasix::syscalls::wasi::path_rename::path_rename::h0da49911ba91acd1
  13:     0x55effc488952 - corosensei::coroutine::on_stack::wrapper::h7b1afa34c668e91d
  14:     0x55efffeee169 - stack_call_trampoline
  15:     0x55effc30f158 - wasmer_vm::trap::traphandlers::on_host_stack::hadab4365f541b038
  16:     0x55effc1f81d4 - wasmer::backend::sys::entities::function::gen_fn_callback_s6::func_wrapper::hf0a71574524bae47
  17:     0x7f16de8f5c11 - <unknown>
  18:     0x7f16de931e19 - <unknown>
  19:     0x7f16de933980 - <unknown>
  20:     0x7f16e0567e3d - <unknown>
  21:     0x7f16e042a901 - <unknown>
  22:     0x7f16e066bf39 - <unknown>
  23:     0x7f16e0544311 - <unknown>
  24:     0x7f16e01894ab - <unknown>
  25:     0x7f16e055022b - <unknown>
  26:     0x7f16e054f75f - <unknown>
  27:     0x7f16e071d9ea - <unknown>
  28:     0x7f16e07147a8 - <unknown>
  29:     0x7f16dea2a6e4 - <unknown>
  30:     0x7f16dea2a896 - <unknown>
  31:     0x7f16e072ee03 - <unknown>

Example crash from Rust

• Repro command: shield run --lang rust --wasmer [WASMER BINARY] library::coretests::coretests-3d2262867062fa53
• Full status file: [tests_rust_results.json](https://github.com/wasmerio/compat-tests/blob/ 8 files changed, 289 insertions(+), 318 deletions(-)/tests_rust_results.json)

crash: RuntimeError: unaligned atomic access
    at core::sync::atomic::AtomicBool::fetch_nand (coretests-797f608686ad0aa5.wasm[14495]:0xffffffff)
    at coretests::atomic::atomic_access_bool (coretests-797f608686ad0aa5.wasm[25901]:0xffffffff)
    at coretests::atomic::atomic_access_bool::{{closure}} (coretests-797f608686ad0aa5.wasm[25900]:0xffffffff)
    at core::ops::function::FnOnce::call_once (coretests-797f608686ad0aa5.wasm[7577]:0xffffffff)
    at test::__rust_begin_short_backtrace (coretests-797f608686ad0aa5.wasm[27649]:0xffffffff)
    at test::types::RunnableTest::run (coretests-797f608686ad0aa5.wasm[27680]:0xffffffff)
    at test::run_test (coretests-797f608686ad0aa5.wasm[27644]:0xffffffff)
    at test::run_tests (coretests-797f608686ad0aa5.wasm[27642]:0xffffffff)
    at test::console::run_tests_console (coretests-797f608686ad0aa5.wasm[27478]:0xffffffff)
    at test::test_main (coretests-797f608686ad0aa5.wasm[27634]:0xffffffff)
    at test::test_main_static (coretests-797f608686ad0aa5.wasm[27635]:0xffffffff)
    at coretests::main (coretests-797f608686ad0aa5.wasm[12082]:0xffffffff)
    at core::ops::function::FnOnce::call_once (coretests-797f608686ad0aa5.wasm[8940]:0xffffffff)
    at std::sys::backtrace::__rust_begin_short_backtrace (coretests-797f608686ad0aa5.wasm[15611]:0xffffffff)
    at std::rt::lang_start::{{closure}} (coretests-797f608686ad0aa5.wasm[675]:0xffffffff)
    at std::rt::lang_start_internal (coretests-797f608686ad0aa5.wasm[27950]:0xffffffff)
    at std::rt::lang_start (coretests-797f608686ad0aa5.wasm[674]:0xffffffff)
    at __main_void (coretests-797f608686ad0aa5.wasm[12083]:0xffffffff)
    at _start (coretests-797f608686ad0aa5.wasm[136]:0xffffffff)

More changed tests

• Python: [tests_python_results.json](https://github.com/wasmerio/compat-tests/blob/ 8 files changed, 289 insertions(+), 318 deletions(-)/tests_python_results.json)
• Node.js: [tests_node_results.json](https://github.com/wasmerio/compat-tests/blob/ 8 files changed, 289 insertions(+), 318 deletions(-)/tests_node_results.json)
• PHP: [tests_php_results.json](https://github.com/wasmerio/compat-tests/blob/ 8 files changed, 289 insertions(+), 318 deletions(-)/tests_php_results.json)
• Rust: [tests_rust_results.json](https://github.com/wasmerio/compat-tests/blob/ 8 files changed, 289 insertions(+), 318 deletions(-)/tests_rust_results.json)

Install shield

• git clone https://github.com/wasmerio/compat-tests.git
• cd compat-tests
• cargo build
• ./target/debug/shield run --lang <LANG> --wasmer [WASMER BINARY] <TEST OR BATCH>

Artifacts

• GitHub Action: https://github.com/wasmerio/anti-regression-shield/actions/runs/24962816486
• Results commit: [https://github.com/wasmerio/compat-tests/commit/ 8 files changed, 289 insertions(+), 318 deletions(-)](https://github.com/wasmerio/compat-tests/commit/ 8 files changed, 289 insertions(+), 318 deletions(-))