Message-ID: <2575e5f7-b11a-020f-06ef-ba42301d7415@linaro.org>
Date:   Tue, 14 Feb 2023 08:57:39 +0100
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Subject: Re: [PATCH v2 13/24] sh/cpu: Make sure play_dead() doesn't return
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To:     Josh Poimboeuf <jpoimboe@kernel.org>, linux-kernel@vger.kernel.org
Cc:     jgross@suse.com, richard.henderson@linaro.org,
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References: <cover.1676358308.git.jpoimboe@kernel.org>
 <d0c3ff5349adfe8fd227acc236ae2c278a05eb4c.1676358308.git.jpoimboe@kernel.org>
From:   =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= <philmd@linaro.org>
In-Reply-To: <d0c3ff5349adfe8fd227acc236ae2c278a05eb4c.1676358308.git.jpoimboe@kernel.org>
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On 14/2/23 08:05, Josh Poimboeuf wrote:
> play_dead() doesn't return.  Make that more explicit with a BUG().
> 
> BUG() is preferable to unreachable() because BUG() is a more explicit
> failure mode and avoids undefined behavior like falling off the edge of
> the function into whatever code happens to be next.
> 
> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
> ---
>   arch/sh/include/asm/smp-ops.h | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/arch/sh/include/asm/smp-ops.h b/arch/sh/include/asm/smp-ops.h
> index e27702130eb6..63866b1595a0 100644
> --- a/arch/sh/include/asm/smp-ops.h
> +++ b/arch/sh/include/asm/smp-ops.h
> @@ -27,6 +27,7 @@ static inline void plat_smp_setup(void)
>   static inline void play_dead(void)
>   {
>   	mp_ops->play_dead();
> +	BUG();
>   }

Shouldn't we decorate plat_smp_ops::play_dead() as noreturn first?