From: Kevin Brodsky <kevin.brodsky@arm.com>
To: Ard Biesheuvel <ardb+git@google.com>,
linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, will@kernel.org,
catalin.marinas@arm.com, mark.rutland@arm.com,
Ard Biesheuvel <ardb@kernel.org>,
Ryan Roberts <ryan.roberts@arm.com>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Liz Prucka <lizprucka@google.com>,
Seth Jenkins <sethjenkins@google.com>,
Kees Cook <kees@kernel.org>, Mike Rapoport <rppt@kernel.org>,
David Hildenbrand <david@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH v4 15/15] arm64: mm: Remap linear aliases of the fixmap page tables read-only
Date: Wed, 29 Apr 2026 15:57:29 +0200 [thread overview]
Message-ID: <21a547ae-7121-4cd1-b203-4d8182eb7cc9@arm.com> (raw)
In-Reply-To: <20260427153416.2103979-32-ardb+git@google.com>
On 27/04/2026 17:34, Ard Biesheuvel wrote:
> [...]
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index 84d81bae07a7..e76fe5b0c5fe 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -1076,6 +1076,11 @@ void __init mark_linear_text_alias_ro(void)
> (unsigned long)__init_begin - (unsigned long)_text,
> pgprot_tagged(PAGE_KERNEL_RO));
>
> + /* Map the fixmap PTE table at __fixmap_pgdir_start R/O in linear map too */
> + update_mapping_prot(__pa_symbol(__fixmap_pgdir_start),
> + (unsigned long)lm_alias(__fixmap_pgdir_start),
> + PAGE_SIZE, pgprot_tagged(PAGE_KERNEL_RO));
Is that definitely just one page?
> +
> remap_linear_data_alias(true);
>
> if (IS_ENABLED(CONFIG_HIBERNATION)) {
next prev parent reply other threads:[~2026-04-29 13:57 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-27 15:34 [PATCH v4 00/15] arm64: Unmap linear alias of kernel data/bss Ard Biesheuvel
2026-04-27 15:34 ` [PATCH v4 01/15] arm64: mm: Map the linear alias of text/rodata as tagged Ard Biesheuvel
2026-04-28 14:16 ` Kevin Brodsky
2026-04-28 16:23 ` Ard Biesheuvel
2026-04-29 7:57 ` Kevin Brodsky
2026-04-29 7:58 ` Ard Biesheuvel
2026-04-27 15:34 ` [PATCH v4 02/15] mm: Make empty_zero_page __ro_after_init Ard Biesheuvel
2026-04-28 12:27 ` Mike Rapoport
2026-04-28 14:16 ` Kevin Brodsky
2026-04-28 19:51 ` David Hildenbrand (Arm)
2026-04-27 15:34 ` [PATCH v4 03/15] arm64: mm: Preserve existing table mappings when mapping DRAM Ard Biesheuvel
2026-04-27 15:34 ` [PATCH v4 04/15] arm64: mm: Preserve non-contiguous descriptors " Ard Biesheuvel
2026-04-27 15:34 ` [PATCH v4 05/15] arm64: mm: Remove bogus stop condition from map_mem() loop Ard Biesheuvel
2026-04-28 14:33 ` Kevin Brodsky
2026-04-27 15:34 ` [PATCH v4 06/15] arm64: mm: Drop redundant pgd_t* argument from map_mem() Ard Biesheuvel
2026-04-28 14:33 ` Kevin Brodsky
2026-04-27 15:34 ` [PATCH v4 07/15] arm64: mm: Permit contiguous descriptors to be rewritten Ard Biesheuvel
2026-04-27 15:34 ` [PATCH v4 08/15] arm64: kfence: Avoid NOMAP tricks when mapping the early pool Ard Biesheuvel
2026-04-27 15:34 ` [PATCH v4 09/15] arm64: mm: Permit contiguous attribute for preliminary mappings Ard Biesheuvel
2026-04-27 15:34 ` [PATCH v4 10/15] arm64: Move fixmap page tables to end of kernel image Ard Biesheuvel
2026-04-29 13:52 ` Kevin Brodsky
2026-04-27 15:34 ` [PATCH v4 11/15] arm64: mm: Don't abuse memblock NOMAP to check for overlaps Ard Biesheuvel
2026-04-29 10:54 ` Kevin Brodsky
2026-04-29 14:23 ` Ard Biesheuvel
2026-04-29 14:30 ` Kevin Brodsky
2026-04-27 15:34 ` [PATCH v4 12/15] arm64: mm: Map the kernel data/bss read-only in the linear map Ard Biesheuvel
2026-04-29 13:54 ` Kevin Brodsky
2026-04-29 14:46 ` Ard Biesheuvel
2026-05-04 8:50 ` Kevin Brodsky
2026-04-27 15:34 ` [PATCH v4 13/15] arm64: mm: Unmap kernel data/bss entirely from " Ard Biesheuvel
2026-04-29 13:55 ` Kevin Brodsky
2026-04-29 17:37 ` Ard Biesheuvel
2026-05-04 8:52 ` Kevin Brodsky
2026-04-27 15:34 ` [PATCH v4 14/15] arm64: mm: Generalize manipulation code of read-only descriptors Ard Biesheuvel
2026-04-29 13:57 ` Kevin Brodsky
2026-04-27 15:34 ` [PATCH v4 15/15] arm64: mm: Remap linear aliases of the fixmap page tables read-only Ard Biesheuvel
2026-04-29 13:57 ` Kevin Brodsky [this message]
2026-04-29 14:08 ` Ard Biesheuvel
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