box64 with ptrace

[fish4terrisa-MSDSM]

Is it possible to emulate ptrace inside box64? Currently I checked user mode linux in box64 and I'm glad to see that ptrace (PTRACE_SETOPTIONS, ${pid} , NULL, PTRACE_O_TRACESYSGOOD) is working in box64 now(previously it abort there), although the steps after it complains

Checking that ptrace can change system call numbers...check_ptrace : expected (SIGTRAP|0x80), got status = 256

now. If ptrace emulation (and things like syscall hook with it) is possible, then it'll be a great breakthough since it'll be the first step to run a whole linux amd64 system with box64.

[ptitSeb]

ptrace support is very very limited. Emulating a whole amd64 system in box64 will not be possible for multiple reason. It is desgined as a Userspace emulator only, and also designed to be build with libc / pthreads and all.All the wrapping phylosophy is part of the base design and cannot be removed. That means threads for exmple, use libpthreads facilities.
It would not be just an issue with ptrace but with many things.
Also the emulator part doesn't handle multiple ring, only user ring and nothing else.

[fish4terrisa-MSDSM]

ptrace support is very very limited. Emulating a whole amd64 system in box64 will not be possible for multiple reason. It is desgined as a Userspace emulator only, and also designed to be build with libc / pthreads and all.All the wrapping phylosophy is part of the base design and cannot be removed. That means threads for exmple, use libpthreads facilities. It would not be just an issue with ptrace but with many things. Also the emulator part doesn't handle multiple ring, only user ring and nothing else.

I understand that it's not possible to emulate a whole system using only box64. But why User Mode Linux is not possible? It doesnt need any kind of hardware support, so no multiple rings are needed(it's called as user mode linux, basically it's an emulated linux kernel running all time in user mode). The only dependency it needs is libc.