linux.fork is broken on arm64

[PucklaJ]

Context

Please provide any relevant information about your setup. This is important in case the issue is not reproducible except for under certain conditions.

• Operating System & Odin Version:

• Please paste odin report output:
  Where to find more information and get into contact when you encounter a bug:

  Website: https://odin-lang.org
  GitHub: https://github.com/odin-lang/Odin/issues

Useful information to add to a bug report:

Odin:    dev-2024-04:efc3f9916
OS:      Arch Linux ARM, Linux 6.7.9-1-MANJARO-ARM
CPU:     ARM64
RAM:     3862 MiB
Backend: LLVM 14.0.6

Expected Behavior

package main

import "core:sys/linux"
import "core:fmt"

main :: proc() {
    using linux

    pid, pid_err := fork()
    fmt.println("after fork")
    assert(pid_err == .NONE)

    if pid == 0 {
        argv := []cstring{
            "/usr/bin/env", nil,
        }
        envp := []cstring{
            "execy_env=1234", nil,
        }
        name := cstring("/usr/bin/env")

        fmt.println("in child")

        e_err := execve(name, raw_data(argv), raw_data(envp))
        fmt.eprintln("unreachable")
        assert(e_err == .NONE)
    } else {
        fmt.println("in parent")
        status: i32
        w_err := syscall(SYS_wait4, Pid(-1), &status, cast(u32)0, cast(rawptr) nil)
        assert(w_err >= 0)

        fmt.printfln("status: {}", status)
    }
}

This program should work, but it sometimes does not.

Current Behavior

This is the syscall for fork on arm64:

syscall(SYS_clone, Signal.SIGCHLD)

The current behaviour is that it sometimes fails to fork.

The clone syscall is documented as follows:

220	clone	man/ cs/	DC	unsigned long	unsigned long	int*	   int*	unsigned long

The syscall should set all parameters.

Failure Information (for bugs)

Please help provide information about the failure if this is a bug. If it is not a bug, please remove the rest of this template.

Steps to Reproduce

Please provide detailed steps for reproducing the issue.

1. step 1
2. step 2
3. you get it...

Failure Logs

Please include any relevant log snippets or files here.