Warning required when total size of indices is greater than INT_MAX

[yanang007]

Describe the bug
Accessing elements in ndarray with size greater than INT_MAX will randomly receive SIGSEGV. (Arch=x64)

To Reproduce

import taichi as ti
ti.init(arch=ti.cpu, debug=True)
x = ti.ndarray(ti.f64, (45000, 45000))
y = ti.ndarray(ti.f64, (48000, 48000))
print('Fine, which is', x[5578, 0], flush=True)  # size < INT_MAX, nothing happened
print('Should be fine, which is', y[5578, 0])  # size > INT_MAX, SIGSEGV received

where 5578 is a random number. Here is an example to find one.

import taichi as ti
ti.init(arch=ti.cpu, debug=True)
arr = ti.ndarray(ti.f64, (48000, 48000))
for i in range(48000):
    print(i, end='', flush=True)
    a = arr[i, 0]
    print(': passed', flush=True)

Log/Screenshots

$ python example.py
[Taichi] version 1.2.2, llvm 10.0.0, commit 608e4b57, win, python 3.9.13
[Taichi] Starting on arch=x64
Fine, which is 0.0
[E 11/29/22 02:00:43.692 117500] Received signal 11 (SIGSEGV)


***********************************
* Taichi Compiler Stack Traceback *
***********************************
0x7fffb02fa8cd: taichi::Time::get_cycles in taichi_python.cp39-win_amd64.pyd
0x7fffb02e9540: taichi::lang::GraphicsDevice::image_to_buffer in taichi_python.cp39-win_amd64.pyd
0x7fffb02e9523: taichi::lang::GraphicsDevice::image_to_buffer in taichi_python.cp39-win_amd64.pyd
0x7fffb02e94f7: taichi::lang::GraphicsDevice::image_to_buffer in taichi_python.cp39-win_amd64.pyd
0x7fffb011253a: taichi::Canvas::triangle in taichi_python.cp39-win_amd64.pyd
0x7fffb0705f1c: taichi::Logger::error in taichi_python.cp39-win_amd64.pyd
0x7fffb02e8eae: taichi::lang::GraphicsDevice::image_to_buffer in taichi_python.cp39-win_amd64.pyd
0x7ff832170ef5: seh_filter_exe in ucrtbase.dll
0x7ff6d7602408: Unknown Function in python.exe
0x7ff82621e390: _C_specific_handler in VCRUNTIME140.dll
0x7ff83499241f: _chkstk in ntdll.dll
0x7ff8349414a4: RtlRaiseException in ntdll.dll
0x7ff834990f4e: KiUserExceptionDispatcher in ntdll.dll
0x7ff8262113b8: memcpy in VCRUNTIME140.dll
0x7fffb05b0b66: PyInit_taichi_python in taichi_python.cp39-win_amd64.pyd
0x7fffb020b50f: taichi::lang::Ndarray::read_float in taichi_python.cp39-win_amd64.pyd
0x7fffb020b3fd: taichi::lang::Ndarray::read_float in taichi_python.cp39-win_amd64.pyd
0x7fffb03b5104: PyInit_taichi_python in taichi_python.cp39-win_amd64.pyd
0x7fffb03cefae: PyInit_taichi_python in taichi_python.cp39-win_amd64.pyd
0x7fffb04acdbb: PyInit_taichi_python in taichi_python.cp39-win_amd64.pyd
0x7fffb04b1905: PyInit_taichi_python in taichi_python.cp39-win_amd64.pyd
0x7fffb04b183f: PyInit_taichi_python in taichi_python.cp39-win_amd64.pyd
0x7fffb0393418: PyInit_taichi_python in taichi_python.cp39-win_amd64.pyd
0x7fffe480205e: PyArg_ParseTuple_SizeT in python39.dll
0x7fffe482f0e9: PyObject_MakeTpCall in python39.dll
0x7fffe4945bc0: PyErr_FormatFromCauseTstate in python39.dll
0x7fffe4839fa4: Py_NewReference in python39.dll
0x7fffe4842f1b: PyEval_EvalFrameDefault in python39.dll
0x7ff827647bf6: PyInit_pydevd_frame_evaluator_win32_39_64 in pydevd_frame_evaluator_win32_39_64.cp39-win_amd64.pyd
0x7fffe483c786: PyFunction_Vectorcall in python39.dll
0x7fffe483c07d: PyFunction_Vectorcall in python39.dll
0x7fffe4868c0c: PyVectorcall_Call in python39.dll
0x7fffe4868afe: PyObject_Call in python39.dll
0x7fffe4843d14: PyEval_EvalFrameDefault in python39.dll
0x7ff827647bf6: PyInit_pydevd_frame_evaluator_win32_39_64 in pydevd_frame_evaluator_win32_39_64.cp39-win_amd64.pyd
0x7fffe483bfb4: PyFunction_Vectorcall in python39.dll
0x7fffe4868c0c: PyVectorcall_Call in python39.dll
0x7fffe4868afe: PyObject_Call in python39.dll
0x7fffe4843d14: PyEval_EvalFrameDefault in python39.dll
0x7ff827647bf6: PyInit_pydevd_frame_evaluator_win32_39_64 in pydevd_frame_evaluator_win32_39_64.cp39-win_amd64.pyd
0x7fffe483c786: PyFunction_Vectorcall in python39.dll
0x7fffe483c07d: PyFunction_Vectorcall in python39.dll
0x7fffe47d53fa: PyObject_SetAttr in python39.dll
0x7fffe47d51d4: PyObject_SetAttr in python39.dll
0x7fffe480a7c2: PyObject_GetItem in python39.dll
0x7fffe4842ea2: PyEval_EvalFrameDefault in python39.dll
0x7ff827647bf6: PyInit_pydevd_frame_evaluator_win32_39_64 in pydevd_frame_evaluator_win32_39_64.cp39-win_amd64.pyd
0x7fffe483c786: PyFunction_Vectorcall in python39.dll
0x7fffe4891f05: PyEval_EvalCodeWithName in python39.dll
0x7fffe4891e47: PyEval_EvalCodeEx in python39.dll
0x7fffe4891da5: PyEval_EvalCode in python39.dll
0x7fffe48919a6: PyType_LookupId in python39.dll
0x7fffe4891926: PyType_LookupId in python39.dll
0x7fffe4867833: PyRun_StringFlags in python39.dll
0x7fffe4891c0a: PyType_LookupId in python39.dll
0x7fffe4891a5f: PyType_LookupId in python39.dll
0x7fffe483a530: Py_NewReference in python39.dll
0x7fffe4842af2: PyEval_EvalFrameDefault in python39.dll
0x7ff827647bf6: PyInit_pydevd_frame_evaluator_win32_39_64 in pydevd_frame_evaluator_win32_39_64.cp39-win_amd64.pyd
0x7fffe483c786: PyFunction_Vectorcall in python39.dll
0x7fffe483a60c: Py_NewReference in python39.dll
0x7fffe4842af2: PyEval_EvalFrameDefault in python39.dll
0x7ff827647bf6: PyInit_pydevd_frame_evaluator_win32_39_64 in pydevd_frame_evaluator_win32_39_64.cp39-win_amd64.pyd
0x7fffe483a226: Py_NewReference in python39.dll
0x7fffe4842f1b: PyEval_EvalFrameDefault in python39.dll
0x7ff827647bf6: PyInit_pydevd_frame_evaluator_win32_39_64 in pydevd_frame_evaluator_win32_39_64.cp39-win_amd64.pyd
0x7fffe483a226: Py_NewReference in python39.dll
0x7fffe4842cf3: PyEval_EvalFrameDefault in python39.dll
0x7ff827647bf6: PyInit_pydevd_frame_evaluator_win32_39_64 in pydevd_frame_evaluator_win32_39_64.cp39-win_amd64.pyd
0x7fffe483a226: Py_NewReference in python39.dll
0x7fffe4842cf3: PyEval_EvalFrameDefault in python39.dll
0x7ff827647bf6: PyInit_pydevd_frame_evaluator_win32_39_64 in pydevd_frame_evaluator_win32_39_64.cp39-win_amd64.pyd
0x7fffe483a226: Py_NewReference in python39.dll
0x7fffe4842cf3: PyEval_EvalFrameDefault in python39.dll
0x7ff827647bf6: PyInit_pydevd_frame_evaluator_win32_39_64 in pydevd_frame_evaluator_win32_39_64.cp39-win_amd64.pyd
0x7fffe483c786: PyFunction_Vectorcall in python39.dll
0x7fffe483c07d: PyFunction_Vectorcall in python39.dll
0x7fffe4838936: PyType_GenericAlloc in python39.dll
0x7fffe4868c0c: PyVectorcall_Call in python39.dll
0x7ff8173475c5: Unknown Function in pydevd_cython_win32_39_64.cp39-win_amd64.pyd
0x7ff817380e52: PyInit_pydevd_cython_win32_39_64 in pydevd_cython_win32_39_64.cp39-win_amd64.pyd
0x7ff817380fe0: PyInit_pydevd_cython_win32_39_64 in pydevd_cython_win32_39_64.cp39-win_amd64.pyd
0x7fffe480205e: PyArg_ParseTuple_SizeT in python39.dll
0x7ff8173475c5: Unknown Function in pydevd_cython_win32_39_64.cp39-win_amd64.pyd
0x7ff81736ca2e: PyInit_pydevd_cython_win32_39_64 in pydevd_cython_win32_39_64.cp39-win_amd64.pyd
0x7ff81735a9aa: PyInit_pydevd_cython_win32_39_64 in pydevd_cython_win32_39_64.cp39-win_amd64.pyd
0x7ff81735b9fb: PyInit_pydevd_cython_win32_39_64 in pydevd_cython_win32_39_64.cp39-win_amd64.pyd
0x7fffe482f0e9: PyObject_MakeTpCall in python39.dll
0x7fffe496c7a9: PyErr_FormatFromCauseTstate in python39.dll
0x7fffe49deaaf: PySys_WriteStdout in python39.dll
0x7fffe49df664: PySys_WriteStdout in python39.dll
0x7fffe49d1a25: Py_FatalError_TstateNULL in python39.dll
0x7fffe49d1ced: Py_FatalError_TstateNULL in python39.dll
0x7fffe494806f: PyErr_FormatFromCauseTstate in python39.dll
0x7ff827647b7d: PyInit_pydevd_frame_evaluator_win32_39_64 in pydevd_frame_evaluator_win32_39_64.cp39-win_amd64.pyd
0x7fffe483c786: PyFunction_Vectorcall in python39.dll
0x7fffe4891f05: PyEval_EvalCodeWithName in python39.dll
0x7fffe4891e47: PyEval_EvalCodeEx in python39.dll
0x7fffe4891da5: PyEval_EvalCode in python39.dll
0x7fffe4891b56: PyType_LookupId in python39.dll
0x7fffe4891a5f: PyType_LookupId in python39.dll
0x7fffe4838f97: PyType_GenericAlloc in python39.dll
0x7fffe48d6410: PyType_GenericNew in python39.dll
0x7fffe48d63cb: PyType_GenericNew in python39.dll
0x7fffe49d2176: Py_FatalError_TstateNULL in python39.dll
0x7fffe4946219: PyErr_FormatFromCauseTstate in python39.dll
0x7fffe4842af2: PyEval_EvalFrameDefault in python39.dll
0x7ff827647b7d: PyInit_pydevd_frame_evaluator_win32_39_64 in pydevd_frame_evaluator_win32_39_64.cp39-win_amd64.pyd
0x7fffe483c786: PyFunction_Vectorcall in python39.dll
0x7fffe483c07d: PyFunction_Vectorcall in python39.dll
0x7fffe48d6410: PyType_GenericNew in python39.dll
0x7fffe48d63cb: PyType_GenericNew in python39.dll
0x7fffe49d20be: Py_FatalError_TstateNULL in python39.dll
0x7fffe4946219: PyErr_FormatFromCauseTstate in python39.dll
0x7fffe4842f1b: PyEval_EvalFrameDefault in python39.dll
0x7ff827647b7d: PyInit_pydevd_frame_evaluator_win32_39_64 in pydevd_frame_evaluator_win32_39_64.cp39-win_amd64.pyd
0x7fffe483bfb4: PyFunction_Vectorcall in python39.dll
0x7fffe48d6410: PyType_GenericNew in python39.dll
0x7fffe48d63cb: PyType_GenericNew in python39.dll
0x7fffe49d20be: Py_FatalError_TstateNULL in python39.dll
0x7fffe4946219: PyErr_FormatFromCauseTstate in python39.dll
0x7fffe4842cf3: PyEval_EvalFrameDefault in python39.dll
0x7fffe483c786: PyFunction_Vectorcall in python39.dll
0x7fffe483a60c: Py_NewReference in python39.dll
0x7fffe4842cf3: PyEval_EvalFrameDefault in python39.dll
0x7fffe483a226: Py_NewReference in python39.dll
0x7fffe4842af2: PyEval_EvalFrameDefault in python39.dll
0x7fffe483c786: PyFunction_Vectorcall in python39.dll
0x7fffe4891f05: PyEval_EvalCodeWithName in python39.dll
0x7fffe4891e47: PyEval_EvalCodeEx in python39.dll
0x7fffe4891da5: PyEval_EvalCode in python39.dll
0x7fffe48919a6: PyType_LookupId in python39.dll
0x7fffe4891926: PyType_LookupId in python39.dll
0x7fffe484638b: PyDict_DelItemString in python39.dll
0x7fffe4846110: PyImport_GetMagicNumber in python39.dll
0x7fffe4846f67: PyRun_SimpleFileExFlags in python39.dll
0x7fffe4845c40: PyRun_AnyFileExFlags in python39.dll
0x7fffe48459ea: Py_MakePendingCalls in python39.dll
0x7fffe48a5a78: Py_RunMain in python39.dll
0x7fffe48a5901: Py_RunMain in python39.dll
0x7fffe48a5e9a: Py_RunMain in python39.dll
0x7fffe491d195: Py_Main in python39.dll
0x7ff6d7601268: Unknown Function in python.exe
0x7ff8332874b4: BaseThreadInitThunk in KERNEL32.DLL
0x7ff8349426a1: RtlUserThreadStart in ntdll.dll

Internal error occurred. Check out this page for possible solutions:
https://docs.taichi-lang.org/docs/install

Additional comments
Please let me know if diagnoses or any other information is needed.

It may be a potential int overflow in indexing, but I haven't seen any for now.

taichi/taichi/program/ndarray.cpp

Lines 135 to 158 in 797feaf

	T Ndarray::read(const std::vector<int> &I) const {
	prog_->synchronize();
	size_t index = flatten_index(total_shape_, I);
	size_t size_ = sizeof(T);
	taichi::lang::Device::AllocParams alloc_params;
	alloc_params.host_write = false;
	alloc_params.host_read = true;
	alloc_params.size = size_;
	alloc_params.usage = taichi::lang::AllocUsage::Storage;
	auto staging_buf_ =
	this->ndarray_alloc_.device->allocate_memory_unique(alloc_params);
	staging_buf_->device->memcpy_internal(
	staging_buf_->get_ptr(),
	this->ndarray_alloc_.get_ptr(/*offset=*/index * sizeof(T)), size_);
	char *const device_arr_ptr =
	reinterpret_cast<char *>(staging_buf_->device->map(*staging_buf_));
	TI_ASSERT(device_arr_ptr);
	T data;
	std::memcpy(&data, device_arr_ptr, size_);
	staging_buf_->device->unmap(*staging_buf_);
	return data;
	}

I noticed that taichi has been tested on even larger scales. If this is an intended behavior or a known limitation for CPU arch, it probably would be better to give a warning about it.

[strongoier]

Hi @yanang007. Thanks for reporting this! Taichi currently uses i32 for indexing so this behavior is known.

it probably would be better to give a warning about it.

Thanks for the suggestion! We should give a warning indeed.

[yanang007]

Thanks for your quick reply! Then should I close this issue or change it into a feature request for the warning message?

[yanang007]

Sorry to repoen the issue. I did see a warning from SNode::create_node, but code like this will still break the program without any alarm.

ti.Matrix.field(3, 3, dtype=ti.i8, shape=(16000, 16000)).to_numpy()

A good idea may be to introduce a unified check for total size somewhere.

[strongoier]

A good idea may be to introduce a unified check for total size somewhere.

Yep. Thanks for the suggestion. I've just marked this issue as a feature request.