From: Steven Rostedt <rostedt@goodmis.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>,
Linux Trace Kernel <linux-trace-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Kees Cook <keescook@chromium.org>,
Dave Hansen <dave.hansen@intel.com>,
Sean Christopherson <seanjc@google.com>,
linux-arch@vger.kernel.org
Subject: Re: [RFC PATCH] text_poke/ftrace/x86: Allow text_poke() to be called in early boot
Date: Mon, 24 Oct 2022 21:05:35 -0400 [thread overview]
Message-ID: <20221024210535.61174928@gandalf.local.home> (raw)
In-Reply-To: <CAHk-=wj_jxetFqMB8VWcJdtOt+CU0r_isyGV4AhEYFxA7YsU7Q@mail.gmail.com>
On Mon, 24 Oct 2022 18:02:32 -0700
Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Mon, Oct 24, 2022 at 5:21 PM Steven Rostedt <rostedt@goodmis.org> wrote:
> >
> > It's all about updating read only pages that are executable with a shadow mm.
>
> Right. And it doesn't actually need the mm at all, all it wants is the
> kernel page tables. Which is why all the "dup_mmap()" stuff seems so
> wrong.
>
> I suspect mm_alloc() does everything that VM actually needs.
>
> IOW, it shouldn't have used the fork() helper, it should have used the
> execve() helper that actually starts out from a clean slate. Because a
> clean slate is exactly what that code wants.
>
> No?
>
Something to look into. But I'm guessing that's best for the next merge
window, and not for the -rc releases?
-- Steve
next prev parent reply other threads:[~2022-10-25 1:29 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-24 23:03 [RFC PATCH] text_poke/ftrace/x86: Allow text_poke() to be called in early boot Steven Rostedt
2022-10-25 0:11 ` Linus Torvalds
2022-10-25 0:21 ` Steven Rostedt
2022-10-25 1:02 ` Linus Torvalds
2022-10-25 1:05 ` Steven Rostedt [this message]
2022-10-25 1:06 ` Linus Torvalds
2022-10-25 10:28 ` Peter Zijlstra
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