Message-ID: <CAPhsuW4rF1cFmdSUZD=Tw4QRmOf=v+V_2EhEphzJA5teqOrH0Q@mail.gmail.com>
Date:   Thu, 9 Jun 2022 15:48:17 -0700
From:   Song Liu <song@...nel.org>
To:     "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
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Subject: Re: [PATCH] kprobes: Enable tracing for mololithic kernel images

On Thu, Jun 9, 2022 at 11:41 AM Edgecombe, Rick P
<rick.p.edgecombe@...el.com> wrote:
>
> On Thu, 2022-06-09 at 06:24 -0700, Luis Chamberlain wrote:

[...]

>
> Like say for a next step we moved prog pack out of bpf into core code,
> gave it it's own copy of module_alloc(), and then made kprobes use it.
> Then we would have something with improved W^X guard rails, and kprobes
> would not depend on modules anymore. I think maybe it's a step in the
> right direction, even if it's not perfect.

I was also thinking about where to put the prog pack allocator eventually.
Shall it be part of mm code or module code?

Btw, prog pack has more challenges with W^X requirement:
1. The arch need to have text poke mechanism;
2. Some users of prog pack need to learn to use the ROXbuffer with text poke,
  for example, how to calculate relative address differently.

Thanks,
Song

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