linux-kernel - Re: [PATCH 1/2] docs/livepatch: Add new compiler considerations doc

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Message-ID: <20200721230442.5v6ah7bpjx4puqva@treble>
Date:   Tue, 21 Jul 2020 18:04:42 -0500
From:   Josh Poimboeuf <jpoimboe@...hat.com>
To:     Joe Lawrence <joe.lawrence@...hat.com>
Cc:     live-patching@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] docs/livepatch: Add new compiler considerations doc

On Tue, Jul 21, 2020 at 12:14:06PM -0400, Joe Lawrence wrote:
> Compiler optimizations can have serious implications on livepatching.
> Create a document that outlines common optimization patterns and safe
> ways to livepatch them.
> 
> Signed-off-by: Joe Lawrence <joe.lawrence@...hat.com>

There's a lot of good info here, but I wonder if it should be
reorganized a bit and instead called "how to create a livepatch module",
because that's really the point of it all.

I'm thinking a newcomer reading this might be lost.  It's not
necessarily clear that there are currently two completely different
approaches to creating a livepatch module, each with their own quirks
and benefits/drawbacks.  There is one mention of a "source-based
livepatch author" but no explanation of what that means.

Maybe it could begin with an overview of the two approaches, and then
delve more into the details of each approach, and then delve even more
into the gory details about compiler optimizations.

Also the kpatch-build section can reference the patch author guide which
we have on github.

-- 
Josh