Date:   Thu, 23 Dec 2021 19:16:18 +0100
From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     Borislav Petkov <bp@alien8.de>
Cc:     X86 ML <x86@kernel.org>,
        Valentin Schneider <valentin.schneider@arm.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Alan Stern <stern@rowland.harvard.edu>,
        Steven Rostedt <rostedt@goodmis.org>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH -v2] notifier: Return an error when a callback has
 already been registered
Message-ID: <YcS88mkwxbO8Qy7c@linutronix.de>
References: <20211202133601.23527-1-bp@alien8.de>
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On 2021-12-23 16:31:01 [+0100], Borislav Petkov wrote:
> From: Borislav Petkov <bp@suse.de>
> 
> Return -EEXIST when a notifier callback has already been registered on a
> notifier chain.
> 
> This should avoid any homegrown registration tracking at the callsite
> like
> 
>   https://lore.kernel.org/amd-gfx/20210512013058.6827-1-mukul.joshi@amd.com
> 
> for example.
> 
> This version is an alternative of
> 
>   https://lore.kernel.org/r/20211108101157.15189-1-bp@alien8.de
> 
> which needed to touch every caller not checking the registration
> routine's return value.
> 
> Signed-off-by: Borislav Petkov <bp@suse.de>

Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

Sebastian