Re: [PATCH v2 11/18] x86/asm/64: Separate cpu_current_top_of_stack from TSS.sp0

From: Thomas Gleixner
Date: Thu Nov 23 2017 - 14:35:02 EST


On Tue, 21 Nov 2017, Andy Lutomirski wrote:

> On 64-bit kernels, we used to assume that TSS.sp0 was the current
> top of stack. With the addition of an entry trampoline, this will
> no longer be the case. Store the current top of stack in TSS.sp1,
> which is otherwise unused but shares the same cacheline.
>
> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>