reloaded-project/reloaded.memory.buffers

[C# & Rust] An implementation of efficient, shared, concurrent and permanent storage of objects in unmanaged memory in static, non-changing locations that last the lifetime of a given process.

reloaded.memory.buffers's Issues

[Rust] Tests Should Delete Physical Memory Mapped File between Runs when Calling `LocatorHeaderFinder::reset`

This sometimes causes test failures in macOS, when tests are ran in different than usual order.
This should probably be fixed.

[Android] On AArch64, Build fails when Running `cross test --target aarch64-linux-android` because it doesn't recognise `__clear_cache` intrinsic.

Tried to use this intrinsic from C (__builtin__)clear_cache).
Tried to use the LLVM export (named __clear_cache).

Both GCC and Clang should recognise this intrinsic, yet build fails (on GCC); but only on ARM based platforms. I have no idea why. Android source itself uses this intrinsic fine. No idea what is going on.

Executable Memory-Mapped Files on Android are Unsupported in non-Root Scenarios

On Android, it appears that creating a memory-mapped file with 'execute' permissions in a location accessible by multiple processes is not possible (without root). The Android platform seems to enforce strict W^X (Write XOR Execute) policies, which prevent memory from being simultaneously writable and executable in shared memory locations.

There's also another issue. To utilize common shared storage in Android, the requisite permissions must be set in AndroidManifest.xml.

However, despite setting the appropriate permissions, creating a RWX memory mapped file on Android does not seem to work regardless. It may be possible if you memory map the file twice (non-writeable for executing, and writeable for writing, but I have not yet tested).

Current Behaviour

Currently on Android, library will not be able to detect existing LocatorHeader(s) created by other instances of the library in the same process. A new LocatorHeader will always be created.

On macOS M1, pages enforce strict W^X and cannot be write and execute at the same time.

Related to: Reloaded-Project/Reloaded.Hooks-rs#1

Currently we toggle between R^X and R^W, because this is forced on us by the mach_ APIs. This is not ideal, in a situation like hooks, it's possible we might be toggling code in process of being executed, in which case, we're smoked.

Unfortunately the JIT APIs pthread_jit_write_protect_np only work on memory allocated with mmap, not the mach APIs, and allocating at specific address with mmap is broken on macOS. Well played.

It would be nice to experiment with mapping each custom page twice over, but that's unfortunately not a possibility right now. Without access to one of these machines, I can't test it very well, short of paying some cloud company for access (lol) or hassling someone too much for my liking.