The idea of handling system calls differently depending on the origin of each
call in the process’s address space is not entirely new. OpenBSD, for
example, disallows system calls entirely if
they are not made from the system’s C library as a security-enhancing
mechanism. At the end of May, Gabriel Krisman Bertazi proposed
a similar mechanism for Linux, but the objective was not security at
all; instead, he is working to make Windows games run better under Wine.
That involves detecting and emulating Windows system calls; this can be
done through origin-based filtering, but that may not be the solution that
is merged in the end.

Source: LWN.net – [$] Emulating Windows system calls in Linux