Re: [patch V6 36/37] x86/entry: Move paranoid irq tracing out of ASM code

From: Thomas Gleixner
Date: Wed May 20 2020 - 11:17:26 EST


Andy Lutomirski <luto@xxxxxxxxxx> writes:

> On Fri, May 15, 2020 at 5:11 PM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>
> I think something's missing here. With this patch applied, don't we
> get to exc_debug_kernel() -> handle_debug() without doing
> idtentry_enter() or equivalent? And that can even enable IRQs.
>
> Maybe exc_debug_kernel() should wrap handle_debug() in some
> appropriate _enter() / _exit() pair?

I'm the one who is missing something here, i.e. the connection of this
patch to #DB. exc_debug_kernel() still looks like this:

nmi_enter_notrace();
handle_debug(regs, dr6, false);
nmi_exit_notrace();

Confused.