That doesn't sound much different from regular vfork()? It isn't that evil, you just need a small assembly shim (or if you're courageous, a bit of massaging the

That doesn't sound much different from regular vfork()? It isn't that evil, you just need a small assembly shim (or if you're courageous, a bit of massaging the compiler output) to safely call another function with its own stack frame, as well as some care to disable signal handlers in the child. It's mostly for silly setuid-binary reasons that the libc people tend to dislike it. Also, there's no way that libc people would want to work with the compiler people to locate the current stack frame to copy. So you'd end up with an assembly shim with a definite stack size anyway.