This change enables Address Sanitizer systemically w/ `make MODE=dbg`.
Our version of Rust's `unsafe` keyword is named `noasan` which is used
for two functions that do aligned memory chunking, like `strcpy.c` and
we need to fix the tiny DEFLATE code, but that's it everything else is
fabulous you can have all the fischer price security blankets you need
Best of all is we're now able to use the ASAN data in Blinkenlights to
colorize the memory dumps. See the screenshot below of a test program:
https://justine.lol/blinkenlights/asan.png
Which is operating on float arrays stored on the stack, with red areas
indicating poisoned memory, and the green areas indicate valid memory.
We always favor calling functions like openat(), fstatat(), etc. because
Linux, XNU, FreeBSD, and OpenBSD all elected to support them, while some
systems like Android love them so much, that they stopped supporting the
old interfaces.
This change ensures that when dirfd is actually a dirfd and not AT_FDCWD
we'll do the right thing on Windows NT. We use an API that's been around
since Vista to accomplish that.
This change also adds exponential backoff to chdir() on Windows since it
seems almost as flaky on Windows 7 as the rmdir() function.
I wanted a tiny scriptable meltdown proof way to run userspace programs
and visualize how program execution impacts memory. It helps to explain
how things like Actually Portable Executable works. It can show you how
the GCC generated code is going about manipulating matrices and more. I
didn't feel fully comfortable with Qemu and Bochs because I'm not smart
enough to understand them. I wanted something like gVisor but with much
stronger levels of assurances. I wanted a single binary that'll run, on
all major operating systems with an embedded GPL barrier ZIP filesystem
that is tiny enough to transpile to JavaScript and run in browsers too.
https://justine.storage.googleapis.com/emulator625.mp4
