On Mon, Mar 30, 2026 at 06:44:15AM -0500, Rob Herring wrote:
On Wed, Feb 25, 2026 at 12:04 AM Coiby Xu <[email protected]> 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 and PowerPC, the missing piece is
to let the kdump kernel know where to find the dm-crypt keys which are
randomly stored in memory reserved for kdump. Introduce a new 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.
Since this property is only needed by the kdump kernel, it won't be
exposed to user space.
[1] https://lore.kernel.org/all/[email protected]/
[2] https://github.com/devicetree-org/dt-schema/pull/181
Cc: Arnaud Lefebvre <[email protected]>
Cc: Baoquan he <[email protected]>
Cc: Dave Young <[email protected]>
Cc: Kairui Song <[email protected]>
Cc: Pingfan Liu <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Krzysztof Kozlowski <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Thomas Staudt <[email protected]>
Cc: Sourabh Jain <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Christophe Leroy (CS GROUP) <[email protected]>
Signed-off-by: Coiby Xu <[email protected]>
---
arch/arm64/kernel/machine_kexec_file.c | 4 ++++
arch/powerpc/kexec/elf_64.c | 4 ++++
drivers/of/fdt.c | 21 +++++++++++++++++++++
drivers/of/kexec.c | 19 +++++++++++++++++++
4 files changed, 48 insertions(+)
Acked-by: Rob Herring (Arm) <[email protected]>
Hi Rob,
Thanks for acknowledging this device tree patch and also merging the
dt-schema PR!
--
Best regards,
Coiby
