On Fri, Jun 19, 2020 at 10:41 AM Borislav Petkov <[email protected]> wrote: > > From: Petteri Aimonen <[email protected]> > > Previously, kernel floating point code would run with the MXCSR control > register value last set by userland code by the thread that was active > on the CPU core just before kernel call. This could affect calculation > results if rounding mode was changed, or a crash if a FPU/SIMD exception > was unmasked. > > Restore MXCSR to the kernel's default value. > > [ bp: Carve out from a bigger patch by Petteri, add feature check, add > FNINIT call too (amluto). ]
Acked-by: Andy Lutomirski <[email protected]> but: shouldn't kernel_fpu_begin() end with a barrier()?
