linux-kernel - Re: [PATCH 0/2] Documentation: fixups for L1D flushing

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Message-ID: <DDJU0415JEBQ.H2SD942NMDWX@google.com>
Date: Thu, 16 Oct 2025 14:54:50 +0000
From: Brendan Jackman <jackmanb@...gle.com>
To: Brendan Jackman <jackmanb@...gle.com>, Jonathan Corbet <corbet@....net>, 
	Thomas Gleixner <tglx@...utronix.de>, Borislav Petkov <bp@...en8.de>, 
	Peter Zijlstra <peterz@...radead.org>, Josh Poimboeuf <jpoimboe@...nel.org>, 
	Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>, Balbir Singh <sblbir@...zon.com>
Cc: <linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>, 
	Kees Cook <kees@...nel.org>
Subject: Re: [PATCH 0/2] Documentation: fixups for L1D flushing

On Wed Oct 15, 2025 at 5:02 PM UTC, Brendan Jackman wrote:
> Signed-off-by: Brendan Jackman <jackmanb@...gle.com>
> ---
> Brendan Jackman (2):
>       Documentation: clarify PR_SPEC_L1D_FLUSH
>       Documentation: fix reference to PR_SPEC_L1D_FLUSH
>
>  Documentation/admin-guide/hw-vuln/l1d_flush.rst | 2 +-
>  Documentation/userspace-api/spec_ctrl.rst       | 6 +++++-
>  2 files changed, 6 insertions(+), 2 deletions(-)
> ---
> base-commit: 0292ef418ce08aad597fc0bba65b6dbb841808ba
> change-id: 20251015-l1d-flush-doc-029f64d2b0d3
>
> Best regards,

I just noticed another issue - the docs say you get -ENXIO if control
isn't possible, but for L1D_FLUSH and INDIR_BRANCH you get -EPERM.

TBH I think this is a bug but it seems like it's still better to just
document it than change the behaviour.