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Subject: Re: [PATCH] livepatch: introduce klp_func called interface
From: zhang warden <zhangwarden@gmail.com>
In-Reply-To: <Zl8mqq6nFlZL+6sb@redhat.com>
Date: Wed, 5 Jun 2024 10:38:30 +0800
Cc: Miroslav Benes <mbenes@suse.cz>,
 Josh Poimboeuf <jpoimboe@kernel.org>,
 Jiri Kosina <jikos@kernel.org>,
 Petr Mladek <pmladek@suse.com>,
 live-patching@vger.kernel.org,
 linux-kernel@vger.kernel.org
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References: <20240520005826.17281-1-zhangwarden@gmail.com>
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To: Joe Lawrence <joe.lawrence@redhat.com>

Hi Joe,

>=20
> Perhaps "responsibility" is a better description.  This would =
introduce
> an attribute that someone's userspace utility is relying on.  It =
should
> at least have a kselftest to ensure a random patch in 2027 doesn't =
break
> it.
I sent this patch to see the what the community thinks about this =
attribute (although it think it is necessary and this will be more =
convenient for users).

If this patch is seems to be good, I will add a kselftest to this =
attribute.

As Miroslav and Petr said, keeping klp_ftrace_handler() as fast as =
possible is also important, which I need to find a way to keep it fast =
(or just setting the state to be true instead of a judgement?).

> The kernel docs provide a lot of explanation of the complete ftracing
> interface.  It's pretty power stuff, though you may also go the other
> direction and look into using the trace-cmd front end to simplify all =
of
> the sysfs manipulation.  Julia Evans wrote a blog [1] a while back =
that
> provides a some more examples.
>=20
> [1] https://jvns.ca/blog/2017/03/19/getting-started-with-ftrace/
>=20
> --
> Joe

Nice of you! Thanks! I will learn it!

Regards,
Wardenjohn