linux-kernel - Re: [PATCH v2 03/24] arm/cpu: Make sure arch_cpu_idle

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Message-ID: <Y+ttS0japRCzHoFM@shell.armlinux.org.uk>
Date:   Tue, 14 Feb 2023 11:15:23 +0000
From:   "Russell King (Oracle)" <linux@...linux.org.uk>
To:     Josh Poimboeuf <jpoimboe@...nel.org>
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Subject: Re: [PATCH v2 03/24] arm/cpu: Make sure arch_cpu_idle_dead() doesn't
 return

On Mon, Feb 13, 2023 at 11:05:37PM -0800, Josh Poimboeuf wrote:
> arch_cpu_idle_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.

This is silly. Just mark the function __noreturn and be done with it.
If the CPU ever executes code past the "b" instruction, it's already
really broken that the extra instructions that BUG() gives will be
meaningless.

This patch does nothing except add yet more bloat the kernel.

Sorry, but NAK.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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