From: Steven Rostedt <rostedt@goodmis.org>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Andy Lutomirski <luto@amacapital.net>,
Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [RFC][PATCH] x86/ftrace: Have ftrace trampolines turn read-only at the end of system boot up
Date: Fri, 1 May 2020 09:24:04 -0400 [thread overview]
Message-ID: <20200501092404.06d1adcb@gandalf.local.home> (raw)
In-Reply-To: <20200501051706.4wkrqwovybt2p6hr@treble>
On Fri, 1 May 2020 00:17:06 -0500
Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> > Would it be easier to just call a new __text_poke_bp() which skips the
> > SYSTEM_BOOTING check, since you know the trampoline will always be
> > read-only?
> >
> > Like:
>
> early_trace_init() is called after mm_init(), so I thought it might
> work, but I guess not:
Yeah, I was about to say that this happens before mm_init() ;-)
It's why we already have magic for enabling function tracing the first time.
Do you see anything wrong with this current solution? It probably needs
more comments, but I wanted to get acceptance on the logic before I go and
pretty it up and send a non RFC patch.
-- Steve
next prev parent reply other threads:[~2020-05-01 13:24 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-01 0:21 Steven Rostedt
2020-05-01 4:47 ` Josh Poimboeuf
2020-05-01 5:17 ` Josh Poimboeuf
2020-05-01 13:24 ` Steven Rostedt [this message]
2020-05-01 15:13 ` Josh Poimboeuf
2020-05-01 16:19 ` Steven Rostedt
2020-05-01 17:29 ` Peter Zijlstra
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