[PATCH v2] arm64/kdump: pass dm-crypt keys to kdump kernel

[Krzysztof Kozlowski]

On Tue, Jan 06, 2026 at 02:22:30PM +0800, Coiby Xu wrote:
> CONFIG_CRASH_DM_CRYPT has been introduced to support LUKS-encrypted
> device dump target by addressing two challenges [1],
>  - Kdump kernel may not be able to decrypt the LUKS partition. For some
>    machines, a system administrator may not have a chance to enter the
>    password to decrypt the device in kdump initramfs after the 1st kernel
>    crashes
> 
>  - LUKS2 by default use the memory-hard Argon2 key derivation function
>    which is quite memory-consuming compared to the limited memory reserved
>    for kdump.
> 
> To also enable this feature for ARM64, we only need to add device tree
> property dmcryptkeys [2] as similar to elfcorehdr to pass the memory
> address of the stored info of dm-crypt keys to the kdump kernel.
> 
> [1] https://lore.kernel.org/all/20250502011246.99238-1-coxu@redhat.com/
> [2] https://github.com/devicetree-org/dt-schema/pull/181
> 
> Cc: Arnaud Lefebvre <arnaud.lefebvre at clever-cloud.com>
> Cc: Baoquan he <bhe at redhat.com>
> Cc: Dave Young <dyoung at redhat.com>
> Cc: Kairui Song <ryncsn at gmail.com>
> Cc: Pingfan Liu <kernelfans at gmail.com>
> Cc: Andrew Morton <akpm at linux-foundation.org>
> Cc: Krzysztof Kozlowski <krzk at kernel.org>
> Signed-off-by: Coiby Xu <coxu at redhat.com>
> ---
> v2
> - Krzysztof
>   - Use imperative mood for commit message
>   - Add dt-schema ABI Documentation
> - Don't print dm-crypt keys address via pr_debug

Your changelog should explicitly document that this has external
dependency on dtschema pull request, so that maintainers know that.

Also, in the future:
Do not attach (thread) your patchsets to some other threads (unrelated
or older versions). This buries them deep in the mailbox and might
interfere with applying entire sets. See also:
https://elixir.bootlin.com/linux/v6.16-rc2/source/Documentation/process/submitting-patches.rst#L830

Best regards,
Krzysztof