/vcrtl

C++ Exceptions in Windows Drivers

Primary LanguageC++MIT LicenseMIT

C++ Exceptions in Windows Drivers

This project implements parts of the Visual Studio runtime library that are needed for C++ exception handling. Currently, x86 and x64 platforms are supported.

Getting started

To use exceptions in your kernel-mode driver, first

C++ exceptions will magically work.

Features

The exception handling code was optimized to significantly reduce the required stack space. On x86, the stack usage is negligible, on x64, approximately 300 bytes are used during handler search, these are, however, reclaimed before the catch handler is called.

No dynamic allocations or thread-local storage is used, everything happens on the stack.

On x64, both FH3 and FH4 C++ exception ABI is supported. FH4 is much better than FH3, prefer it.

No string comparisons are done during exception dispatch.

Limitations

An exception must not leave the module in which it was thrown, otherwise the dispatcher will bug-check.

No SEH exception may pass through frames in which you do C++ exception handling (this includes functions with try/catch blocks or functions marked as noexcept, or functions with automatic variables with non-trivial destructors). This will be detected and you'll get a bug-check.

TODO

Although /GS is supported, the frame cookies aren't checked yet.