linux-kernel - Re: [PATCH v3 1/1] x86/boot/compressed: Fix avoiding memmap in physical KASLR

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Message-ID: <20260113112701.GDaWYsBYgLvfcHzyqs@fat_crate.local>
Date: Tue, 13 Jan 2026 12:27:01 +0100
From: Borislav Petkov <bp@...en8.de>
To: Michał Cłapiński <mclapinski@...gle.com>
Cc: Dave Hansen <dave.hansen@...el.com>, Ard Biesheuvel <ardb@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Chris Li <chrisl@...nel.org>, x86@...nel.org,
	"H. Peter Anvin" <hpa@...or.com>,
	Dan Williams <dan.j.williams@...el.com>,
	Pasha Tatashin <pasha.tatashin@...een.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 1/1] x86/boot/compressed: Fix avoiding memmap in
 physical KASLR

On Tue, Jan 13, 2026 at 12:21:25PM +0100, Michał Cłapiński wrote:
> Currently, if you have 4 or fewer memmaps, KASLR correctly avoids
> putting the kernel there. That just works now and Ard's change would
> disable that.

And why do we care about 4 or fewer memmaps? Is that a valid use case which we
have to support? 4 is magic but 5 is a no-no?

-- 
Regards/Gruss,
    Boris.

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