Re: User mode emulation: hooking shared libraries to host implementations

[Peter Maydell]

On Thu, 25 Jun 2020 at 22:06, ardi <ardillasdelmonte@gmail.com> wrote:
> I'd like to know if there's any functionality in the QEMU user mode
> emulation that lets you replace, in the emulated program, function
> calls to shared libraries into host implementations (note: when I say
> "host implementations", I don't mean that it must really be a true
> shared lib in the host... instead, simply static linking the host
> implementation into the qemu emulator would be fine, and less
> complex).

No, we don't have anything like that. QEMU's user-mode emulation
doesn't know anything about the shared library/dynamic linker
infrastructure of the guest program -- we just (like the real
kernel) load the binary and its dynamic linker, implement the
syscalls, and let the guest code do the rest.

> If QEMU doesn't support this but you happen to know of any other
> project doing this, please tell!!

I think valgrind has infrastructure like this for intercepting
library/function calls, but of course it's same-arch-to-same-arch
and really intended for instrumentation.

thanks
-- PMM