On 9 August 2017 at 13:05, Dave Martin <[email protected]> wrote: > Kernel-mode NEON will corrupt the SVE vector registers, due to the > way they alias the FPSIMD vector registers in the hardware. > > This patch ensures that any live SVE register content for the task > is saved by kernel_neon_begin(). The data will be restored in the > usual way on return to userspace. > > Signed-off-by: Dave Martin <[email protected]> > --- > arch/arm64/kernel/fpsimd.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c > index 955c873..b7fb836 100644 > --- a/arch/arm64/kernel/fpsimd.c > +++ b/arch/arm64/kernel/fpsimd.c > @@ -758,8 +758,10 @@ void kernel_neon_begin(void) > __this_cpu_write(kernel_neon_busy, true); > > /* Save unsaved task fpsimd state, if any: */ > - if (current->mm && !test_and_set_thread_flag(TIF_FOREIGN_FPSTATE)) > - fpsimd_save_state(¤t->thread.fpsimd_state); > + if (current->mm) { > + task_fpsimd_save(); > + set_thread_flag(TIF_FOREIGN_FPSTATE); > + } > > /* Invalidate any task state remaining in the fpsimd regs: */ > __this_cpu_write(fpsimd_last_state, NULL);
Reviewed-by: Ard Biesheuvel <[email protected]> _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
