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]>
