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Date:   Fri, 29 Apr 2022 10:10:58 -0300
From:   Wander Lairson Costa <wander@redhat.com>
To:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc:     Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>,
        Sean Christopherson <seanjc@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
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        Andi Kleen <ak@linux.intel.com>,
        Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@linux.intel.com>,
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        Varad Gautam <varad.gautam@suse.com>,
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        Dave Hansen <dave.hansen@intel.com>,
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        Mike Rapoport <rppt@kernel.org>,
        David Hildenbrand <david@redhat.com>, x86@kernel.org,
        linux-mm@kvack.org, linux-coco@lists.linux.dev,
        linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCHv5 06/12] x86/boot/compressed: Handle unaccepted memory
Message-ID: <Ymvj4ssnzrf74tHl@fedora>
References: <20220425033934.68551-1-kirill.shutemov@linux.intel.com>
 <20220425033934.68551-7-kirill.shutemov@linux.intel.com>
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On Mon, Apr 25, 2022 at 06:39:28AM +0300, Kirill A. Shutemov wrote:
> The firmware will pre-accept the memory used to run the stub. But, the
> stub is responsible for accepting the memory into which it decompresses
> the main kernel. Accept memory just before decompression starts.
> 
> The stub is also responsible for choosing a physical address in which to
> place the decompressed kernel image. The KASLR mechanism will randomize
> this physical address. Since the unaccepted memory region is relatively
> small, KASLR would be quite ineffective if it only used the pre-accepted
> area (EFI_CONVENTIONAL_MEMORY). Ensure that KASLR randomizes among the
> entire physical address space by also including EFI_UNACCEPTED_MEMOR

nit: s/EFI_UNACCEPTED_MEMOR/EFI_UNACCEPTED_MEMORY./

[snip]