linux-kernel - Re: [RFC][PATCH 1/2] kthread: Add is_user_thread() and is_kernel

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Message-ID: <20250426083745.77590827@batman.local.home>
Date: Sat, 26 Apr 2025 08:37:45 -0400
From: Steven Rostedt <rostedt@...dmis.org>
To: Borislav Petkov <bp@...en8.de>
Cc: linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org, Masami
 Hiramatsu <mhiramat@...nel.org>, Mark Rutland <mark.rutland@....com>,
 Mathieu Desnoyers <mathieu.desnoyers@...icios.com>, Andrew Morton
 <akpm@...ux-foundation.org>, Peter Zijlstra <peterz@...radead.org>, Linus
 Torvalds <torvalds@...ux-foundation.org>, Ingo Molnar <mingo@...hat.com>,
 x86@...nel.org, Kees Cook <kees@...nel.org>, bpf@...r.kernel.org, Tejun Heo
 <tj@...nel.org>, Julia Lawall <Julia.Lawall@...ia.fr>, Nicolas Palix
 <nicolas.palix@...g.fr>, cocci@...ia.fr
Subject: Re: [RFC][PATCH 1/2] kthread: Add is_user_thread() and
 is_kernel_thread() helper functions

On Sat, 26 Apr 2025 14:08:46 +0300
Borislav Petkov <bp@...en8.de> wrote:

> >+static __always_inline bool is_kernel_thread(struct task_struct *task)
> >+{
> >+	return task->flags & PF_KTHREAD;  
> 
> return !is_user_thread(task);
> 
> or the other way around. 

Yeah, I thought about doing that but decided against it.

As Kees mentioned to use !!, I think using the !is_user_thread() is a
better approach.

-- Steve