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From: Borislav Petkov <bp@alien8.de>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Xin Li <xin@zytor.com>, Borislav Petkov <bp@kernel.org>,
	Xin Li <xin3.li@intel.com>, X86 ML <x86@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86/cpufeatures: Correct LKGS feature flag description
Date: Wed, 15 Oct 2025 17:49:11 +0200	[thread overview]
Message-ID: <20251015154911.GCaO_Cd0XNyE8bi5Db@fat_crate.local> (raw)
In-Reply-To: <9B0843ED-5207-4A42-A95B-1DB5314DE747@zytor.com>

On Wed, Oct 15, 2025 at 08:44:55AM -0700, H. Peter Anvin wrote:
> >> Except that that is also wrong, because that's not all of what the instruction does. "Load user space GS" is really what it does, despite the initiate historical naming.
> >> 
> >
> >Do you mean the load of GS attributes by LKGS is still missing?
> 
> Yes. It's really a modified MOV GS,... instruction that loads the base, limit, selector, and attributes; it just loads the base into a different place.

Ok, "Load user space GS base" it is. Considering how you can't load any other
GS.base due to it GPing for CPL > 0.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

  reply	other threads:[~2025-10-15 15:49 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-15 10:35 Borislav Petkov
2025-10-15 15:08 ` Xin Li
2025-10-15 15:18   ` H. Peter Anvin
2025-10-15 15:34     ` Xin Li
2025-10-15 15:36       ` H. Peter Anvin
2025-10-15 15:41         ` Xin Li
2025-10-15 15:44           ` H. Peter Anvin
2025-10-15 15:49             ` Borislav Petkov [this message]
2025-10-16  3:12               ` H. Peter Anvin
2025-10-16 12:41                 ` Borislav Petkov

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