On 11/25, Amnon Shiloh wrote: > > 2) I was then told (in my own words): "oh, don't worry, the vsyscall page > has now been minimized, all it contains now is *real* system calls, > and it always calls them".
Not sure where did you get this idea ;) From the very beginning you were told that EMULATE mode doesn't do this. The NATIVE mode should be fine, yes. > 6) I just suggested an alternative: to have the whole vsyscall page > removed on a per-process basis. I accept your reply that this is > not possible. Yes, this is not possible. > 7) I suggested a third alternative: to have the vsyscall page be > unexecutable on a per-process basis, Like above, this is simply not possible. And at the same time the vsyscall page is already unexecutable in EMULATE mode, but globally. > 8) Any solution that allows a ptracer to prevent its traced process > from entering the vsyscall page and execute there system-calls > unchecked (thus in effect escape its jailer), would do for me. Well. I am even more confused... probably this was already discussed and I missed this, but. Why do you need to _prevent_, say, sys_gettimeofday()? Why we can't change emulate_vsyscall() to respect PTRACE_SYSCALL and report TRAP_VSYSCALL or PTRACE_EVENT_VSYSCALL as I tried to suggest in http://marc.info/?l=linux-kernel&m=135343635523715 ? You previously replied that this can not work. Now that you see that this _can_ work, could you please explain why this is not enough? Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
