linux-kernel - Re: [patch 5/8] x86/entry/common: Provide trace/kprobe safe exit to user space functions

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Date:   Tue, 25 Feb 2020 21:45:11 -0800
From:   Andy Lutomirski <luto@...nel.org>
To:     Thomas Gleixner <tglx@...utronix.de>,
        LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, Steven Rostedt <rostedt@...dmis.org>,
        Brian Gerst <brgerst@...il.com>,
        Juergen Gross <jgross@...e.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Arnd Bergmann <arnd@...db.de>
Subject: Re: [patch 5/8] x86/entry/common: Provide trace/kprobe safe exit to
 user space functions

On 2/25/20 2:08 PM, Thomas Gleixner wrote:
> Split prepare_enter_to_user_mode() and mark it notrace/noprobe so the irq
> flags tracing on return can be put into it.

Is our tooling clever enough for thsi to do anything?  You have a static
inline that is only called in one place, and the caller is notrace and
NOKPROBE.  Does this actually allow tracing in the static inline callee?

--Andy