On Mon, May 02, 2016 at 02:18:17PM -0700, Yu-cheng Yu wrote: > Before Linux gets into copy_fpstate_to_sigframe(), > current->thread.fpu.fpstate_active must be true. > For eagerfpu, fpregs_active() must also be true. > For lazyfpu, once we try to do FSAVE/FXSAVE/XSAVE, > fpregs_active() will become true as well. > > We should have not based on boot_cpu_has(X86_FEATURE_XSAVES) > at all. > > Why don't we make it simple and always copy_fpregs_to_signal_frame()? > Or, only for the lazy case, i.e. !fpregs_active(), we do __copy_to_user().
For (lazy && not XSAVES) actually!
