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From: Marc Zyngier <maz@kernel.org>
To: fanqincui  <fanqincui@163.com>
Cc: "Will Deacon" <will@kernel.org>,
	catalin.marinas@arm.com, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	"Fanqin Cui" <cuifq1@chinatelecom.cn>,
	hanht2@chinatelecom.cn
Subject: Re: [PATCH] arm64/module: Support for patching modules during runtime
Date: Mon, 11 Aug 2025 09:01:43 +0100	[thread overview]
Message-ID: <86zfc68exk.wl-maz@kernel.org> (raw)
In-Reply-To: <3d4011c0.6aaa.198981027d7.Coremail.fanqincui@163.com>

On Mon, 11 Aug 2025 08:37:32 +0100,
fanqincui <fanqincui@163.com> wrote:
> 
> Hi will,
> Yes, you are right. The alternative callback function lives inside the module.
> This callback function is actually similar to kvm_update_va_mask in KVM;
> 
> The module's callback function calculates some values based on
> the current CPU features and then performs the replacement.
> 
> The .text.alternative_cb section is actually marked as SHF_EXECINSTR | SHF_ALLOC
> during compilation, so intersections() includes this section and sets it as executable later.

I'm worried there is a chicken-and-egg problem here. What if the
callback itself requires patching via some other alternative? Is there
a guarantee that this always performed in the correct order?

	M.

-- 
Without deviation from the norm, progress is not possible.

  parent reply	other threads:[~2025-08-11  8:01 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-08-07  7:27 [PATCH] arm64/module: Support for patching modules during runtime fanqincui
2025-08-08 11:54 ` Will Deacon
     [not found]   ` <3d4011c0.6aaa.198981027d7.Coremail.fanqincui@163.com>
2025-08-11  8:01     ` Marc Zyngier [this message]
2025-08-11  8:32       ` fanqincui
2025-08-11  8:55         ` Marc Zyngier
2025-08-11  9:57           ` fanqincui
2025-08-11 11:49             ` Marc Zyngier
2025-08-11 12:05       ` Will Deacon
2025-08-11 12:13         ` Mark Rutland

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