>No, simply doing an fnclex will not do the trick.
>
>If you do not know the details of Xenomai and Linux FPU handling on x86,
>I advise you to let xenomai handle the fault, it does it without
>switching to secondary mode, so, you can use it. I do not want to
>explain you how it works because it is rather hairy, so, the only way to
>understand, if you really want to, is to read the xenomai and linux
>relevant sources.

I need to manage exceptions in a different way of the x86 default so I have to unmask fpu exceptions. I have read and follow how it works but in xenomai fpu exceptions invoke a switch to linux...

int xnpod_trap_fault(xnarch_fltinfo_t *fltinfo)
{
    ...
    if (xnpod_shadow_p()) {
        ...
        xnshadow_relax(xnarch_fault_notify(fltinfo));
    }
    return 0;
}

so there is not in the source code an example on how to trap exception and remain into real time task...