Re: [PATCH v4 05/27] x86: Replace ist_enter() with nmi_enter()

From: Steven Rostedt
Date: Mon Feb 24 2020 - 11:48:04 EST


On Mon, 24 Feb 2020 17:34:09 +0100
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> Looking at nmi_enter(), that leaves trace_hardirq_enter(), since we know
> we marked rcu_nmi_enter() as NOKPROBES, per the patches elsewhere in
> this series.

Maybe this was addressed already in the series, but I'm just looking at
Linus's master branch we have:

#define nmi_enter() \
do { \
arch_nmi_enter(); \
printk_nmi_enter(); \
lockdep_off(); \
ftrace_nmi_enter(); \
BUG_ON(in_nmi()); \
preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \
rcu_nmi_enter(); \
trace_hardirq_enter(); \
} while (0)


Just want to confirm that printk_nmi_enter(), lockdep_off(),
and ftrace_nmi_enter() are all marked fully with NOKPROBE.

-- Steve