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    SubjectRe: [patch V3 60/66] x86/fpu/signal: Remove the legacy alignment check
    On Fri, Jun 18, 2021 at 04:19:23PM +0200, Thomas Gleixner wrote:
    > Checking for the XSTATE buffer being 64 byte aligned and if not deciding
    > just to restore the FXSR state is daft.
    >
    > If user space provides an unaligned math frame and has the extended state
    > magic set in the FX software reserved bytes, then it really can keep the
    > pieces.
    >
    > If the frame is unaligned and the FX software magic is not set, then
    > fx_only is already set and the restore will use fxrstor.
    >
    > Remove it.
    >
    > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    > ---
    > arch/x86/kernel/fpu/signal.c | 3 ---
    > 1 file changed, 3 deletions(-)
    >
    > --- a/arch/x86/kernel/fpu/signal.c
    > +++ b/arch/x86/kernel/fpu/signal.c
    > @@ -306,9 +306,6 @@ static int __fpu_restore_sig(void __user
    > }
    > }
    >
    > - if ((unsigned long)buf_fx % 64)
    > - fx_only = 1;
    > -
    > if (!ia32_fxstate) {
    > /*
    > * Attempt to restore the FPU registers directly from user

    Nice, that was really daft.

    Reviewed-by: Borislav Petkov <bp@suse.de>

    --
    Regards/Gruss,
    Boris.

    SUSE Software Solutions Germany GmbH, GF: Felix Imendörffer, HRB 36809, AG Nürnberg

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