| Date | Tue, 22 Jun 2021 19:40:23 +0200 | From | Borislav Petkov <> | Subject | Re: [patch V3 60/66] x86/fpu/signal: Remove the legacy alignment check |
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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.
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