linux-kernel - Re: [PATCH v2] arm64/gcs: Don't call gcs_free() when releasing task

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Message-Id: <175258790439.3684657.2697022341807842240.b4-ty@kernel.org>
Date: Thu, 17 Jul 2025 11:46:17 +0100
From: Will Deacon <will@...nel.org>
To: Catalin Marinas <catalin.marinas@....com>,
	Mark Brown <broonie@...nel.org>
Cc: kernel-team@...roid.com,
	Will Deacon <will@...nel.org>,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] arm64/gcs: Don't call gcs_free() when releasing task_struct

On Mon, 14 Jul 2025 12:21:27 +0100, Mark Brown wrote:
> Currently we call gcs_free() when releasing task_struct but this is
> redundant, it attempts to deallocate any kernel managed userspace GCS
> which should no longer be relevant and resets values in the struct we're
> in the process of freeing.
> 
> By the time arch_release_task_struct() is called the mm will have been
> disassociated from the task so the check for a mm in gcs_free() will
> always be false, for threads that are exiting leaving the mm active
> deactivate_mm() will have been called previously and freed any kernel
> managed GCS.
> 
> [...]

Applied to arm64 (for-next/misc), thanks!

[1/1] arm64/gcs: Don't call gcs_free() when releasing task_struct
      https://git.kernel.org/arm64/c/75fdf823f94b

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev