linux-kernel - Re: [PATCH v3] kprobe/ftrace: bail out if ftrace was killed

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Date: Mon, 6 May 2024 18:50:20 -0400
From: Steven Rostedt <rostedt@...dmis.org>
To: Christophe Leroy <christophe.leroy@...roup.eu>
Cc: Stephen Brennan <stephen.s.brennan@...cle.com>, Masami Hiramatsu
 <mhiramat@...nel.org>, Mark Rutland <mark.rutland@....com>, Guo Ren
 <guoren@...nel.org>, Huacai Chen <chenhuacai@...nel.org>, WANG Xuerui
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 "Aneesh Kumar K.V" <aneesh.kumar@...nel.org>, "Naveen N. Rao"
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 Alexander Gordeev <agordeev@...ux.ibm.com>, Christian Borntraeger
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Subject: Re: [PATCH v3] kprobe/ftrace: bail out if ftrace was killed

On Mon, 6 May 2024 14:46:57 +0000
Christophe Leroy <christophe.leroy@...roup.eu> wrote:

> Isn't it safer to provide a fonction rather than a direct access to a 
> variable ?
> 
> By the way, wouldn't it be more performant to use a static branch (jump 
> label) ?

A static branch could work, but the point of this is that if ftrace
failed, it was likely due to an issue with text modification. Do we want to
stop it via text modification?

-- Steve