Warlich, Christof writes: > Andi Kleen <[email protected]> writes: > > The FP registers are restored lazily, but the state for this is kept in > > the kernel. > > I'm not sure if I understand "lazily" in this context: Do you mean that FP > registers _are_ restored within the kernel, but _not_ from a (possibly > modified) > ucontext of a userspace signal handler? If so, do you know a reason why the > GP > registers are so nicely restored from userspace, but not the FP registers? > > > One easy way may be to catch the FPU exception too and clear from there? > > Hmm - I _do_ catch SIGFPE in my userspace signal handler, but I obviously > can't clear the FP exceptions from there. This, together with your answer > so far, makes me conclude that there may be no way to achieve my goal from > userspace, right :-(?
Write to the fpstate ->mxcsr and ->swd fields in the sigaction handler's uc_mcontext. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
