Message ID | 1507660725-7986-18-git-send-email-Dave.Martin@arm.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
On Tue, Oct 10, 2017 at 07:38:34PM +0100, Dave P Martin 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 <Dave.Martin@arm.com> > Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 5673f50..b1d383a 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -909,8 +909,10 @@ 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);