From: "Ard Biesheuvel" <ardb@kernel.org>
To: "Kevin Brodsky" <kevin.brodsky@arm.com>,
"Ard Biesheuvel" <ardb+git@google.com>,
linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, "Will Deacon" <will@kernel.org>,
"Catalin Marinas" <catalin.marinas@arm.com>,
"Mark Rutland" <mark.rutland@arm.com>,
"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 01/15] arm64: mm: Map the linear alias of text/rodata as tagged
Date: Tue, 28 Apr 2026 18:23:48 +0200 [thread overview]
Message-ID: <6f514d91-c8ce-473f-8383-f3b9a4cc2f7a@app.fastmail.com> (raw)
In-Reply-To: <82091dd4-9d11-4054-89ec-99aadaeec7b2@arm.com>
Hi Kevin,
On Tue, 28 Apr 2026, at 16:16, Kevin Brodsky wrote:
> On 27/04/2026 17:34, Ard Biesheuvel wrote:
>> From: Ard Biesheuvel <ardb@kernel.org>
>>
>> Before moving the empty_zero_page into the __ro_after_init section, make
>> sure it has the memory-tagged type. This is needed to ensure that
>> cpu_enable_mte() will be able to initialize the tags correctly.
>
> mark_linear_text_alias_ro() is called after all features have been
> detected and enabled, so do we actually need this?
>
> AFAICT the lines that matter for cpu_enable_mte() are those, in map_mem():
>
> __map_memblock(pgdp, kernel_start, kernel_end,
> PAGE_KERNEL, NO_CONT_MAPPINGS);
>
> It is probably this call that needs to be changed to use
> pgprot_tagged(PAGE_KERNEL).
>
I see. I guess we should probably update both, no?
next prev parent reply other threads:[~2026-04-28 16:24 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 [this message]
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
2026-04-29 14:08 ` Ard Biesheuvel
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