On Wed, May 6, 2009 at 14:54, Ingo Molnar <mingo@xxxxxxx> wrote: > Which other system calls would you like to use? Futexes might be > one, for fast synchronization primitives? There are a large number of system calls that "normal" C/C++ code uses quite frequently, and that are not security sensitive. A typical example would be gettimeofday(). But there are other system calls, where the sandbox would not really need to inspect arguments as the call does not expose any exploitable interface. It is currently awkward that in order to use seccomp we have to intercept all system calls and provide alternative implementations for them; whereas we really only care about a comparatively small number of security critical operations that we need to restrict. Also, any redirected system call ends up incurring at least two context switches, which is needlessly expensive for the large number of trivial system calls. We are quite happy that read() and write(), which are quite important to us, do not incur this penalty. Markus
