There are no dir components, so you would think that this was
unreachable, however we have observed on macOS two processes racing to
do openat() with O_CREAT manifest in ENOENT.
closes#12138
Today I found out that posix_spawn is trash. It's actually implemented
on top of fork/exec inside of libc (or libSystem in the case of macOS).
So, anything posix_spawn can do, we can do better. In particular, what
we can do better is handle spawning of child processes that are
potentially foreign binaries. If you try to spawn a wasm binary, for
example, posix spawn does the following:
* Goes ahead and creates a child process.
* The child process writes "foo.wasm: foo.wasm: cannot execute binary file"
to stderr (yes, it prints the filename twice).
* The child process then exits with code 126.
This behavior is indistinguishable from the binary being successfully
spawned, and then printing to stderr, and exiting with a failure -
something that is an extremely common occurrence.
Meanwhile, using the lower level fork/exec will simply return ENOEXEC
code from the execve syscall (which is mapped to zig error.InvalidExe).
The posix_spawn behavior means the zig build runner can't tell the
difference between a failure to run a foreign binary, and a binary that
did run, but failed in some other fashion. This is unacceptable, because
attempting to excecve is the proper way to support things like Rosetta.
The TurboSHAKE paper just got published:
https://eprint.iacr.org/2023/342.pdf
and unlike the previous K12 paper, suggests 0x1F instead of 0x01
as the default value for "D".
For data symbols we will now store its virtual address. This means
we do no longer have to calculate it each time a relocation asks
for the address. This is now done for all data symbols only once
rather than every single relocation for that symbol.
This now also allows us directly store the virtual address of synthetic
symbols without having to create an atom for them. This means we also
don't need to have a "synthetic" segment any longer and do not emit
the synthetic symbols such as __heap_end and __heap_base into the final
binary.
* Fix SHA3 with streaming
Leftover bytes should be added to the buffer, not to the state.
(or, always to the state; we can and probably should eventually get
rid of the buffer)
Fixes#14851
* Add a test for SHA-3 with streaming
