John Starks

Virtualization architect at Microsoft. WSL, Hyper-V, Windows containers, Azure.

[John Starks @gigastarks]

@filpizlo What were they checking for with cpuid that didn’t require further inline asm?

[John Starks @gigastarks]

@filpizlo @redneckleeusmc But good for Fil-C that the first one is UB, right? Improves the odds that things will work without patches.

The rest are obnoxious. I especially loathe the TBAA stuff, Rust got that one right.

[John Starks @gigastarks]

@redneckleeusmc @filpizlo Sure. But it’s usually shortsighted to depend on behaviors that differ between mainstream vendors. realloc(p,0) is a bad idea if you ever want your code to run on both Linux and BSD, for example.

[John Starks @gigastarks]

@redneckleeusmc @filpizlo If these behaviors are fine to depend on, then why not fix the C standard to guarantee them? Why won’t the committee agree to that?

[John Starks @gigastarks]

@filpizlo How do signal handlers for hardware exceptions (SIGBUS, SIGILL, etc.) work? They can't be deferred to a safepoint.

[John Starks @gigastarks]

@filpizlo @lcc_27 Yeah, makes sense.

What does lower fidelity look like?

[John Starks @gigastarks]

@filpizlo @lcc_27 I think for Windows you’d need to create a much wider “syscall” layer wrapping all the Win32 APIs you want to support, since you can’t rebuild the system DLLs with the Fil-C ABI. This seems impractical.

[John Starks @gigastarks]

@filpizlo Because IIUC, everything in your binary has to be built with Fil-C—it’s a new ABI, incompatible with existing libraries. So if your C code uses a Rust lib, you can’t use Fil-C today.

[John Starks @gigastarks]

@filpizlo How much of Fil-C is in clang vs llvm? What would it take to extend Fil-C to support other LLVM-backed languages (such as Rust)?

[John Starks @gigastarks]

@filpizlo @learntToCode Are syscalls really that different with Fil-C? I.e., Fil-C needs some encoding of the semantics of the syscall in order to validate inputs, right? No different from writing a safe wrapper around an (unsafe) syscall. Just a question of where the escape hatch is.

[Craig Loewen @craigaloewen]

Very proud to announce that the Windows Subsystem for Linux is now open source!

https://t.co/2yJVi2Xc6U

[John Starks @gigastarks]

@burntsushi5 Finally, an explanation for your moniker.

[John Starks @gigastarks]

@gerhart_x @clift_m We are working on improving the TLFS. If you have specific areas you’d like to see addressed, let me know.

[x86matthew @x86matthew]

I created a hypervisor-based emulator for Windows x64 binaries. This project uses Windows Hypervisor Platform to build a virtualized user-mode environment, allowing syscalls and memory accesses to be logged or intercepted. https://t.co/KbsWfdLT3D

Project:
https://t.co/xJvm24qqXv

[John Starks @gigastarks]

@kromych @x86matthew Should work… we added support a good while ago for hot add of VP after partition setup.

[Dmitrii Kovanikov @ChShersh]

I hate generic ‘utils’, ‘helpers’ and ‘miscellaneous’ directories and modules in software projects.

But it’s been surprisingly hard to get rid of them.

I feel like there’s a lesson here. Every house has a storage box where you just store random stuff.

[John Starks @gigastarks]

@charliermarsh @stanzillaz Hey, thanks. I’ll give it another go soon.

[John Starks @gigastarks]

So, I’m trying to install manim and… are Python people okay?

[John Starks @gigastarks]

@stanzillaz @charliermarsh Looked promising, but I hit some known bug where it hard codes some CFLAGS or something from their build machine, and those flags reference paths that don’t exist on my machine, so random dependencies fail to build.