kernel/git/stable/linux.git/drivers/of/kexec.c, branch master

arm64: kexec_file: Add support for crashkernel CMA reservation

2026-06-30T15:49:06+00:00

Commit 35c18f2933c5 ("Add a new optional ",cma" suffix to the crashkernel= command line option") and commit ab475510e042 ("kdump: implement reserve_crashkernel_cma") added CMA support for kdump crashkernel reservation. Crash kernel memory reservation wastes production resources if too large, risks kdump failure if too small, and faces allocation difficulties on fragmented systems due to contiguous block constraints. The new CMA-based crashkernel reservation scheme splits the "large fixed reservation" into a "small fixed region + large CMA dynamic region": the CMA memory is available to userspace during normal operation to avoid waste, and is reclaimed for kdump upon crash—saving memory while improving reliability. So extend crashkernel CMA reservation support to arm64. The following changes are made to enable CMA reservation: - Parse and obtain the CMA reservation size along with other crashkernel parameters. - Call reserve_crashkernel_cma() to allocate the CMA region for kdump. - Include the CMA-reserved ranges for kdump kernel to use. - Exclude the CMA-reserved ranges from the crash kernel memory to prevent them from being exported through /proc/vmcore, which is already done in the crash core. Update kernel-parameters.txt to document CMA support for crashkernel on arm64 architecture. Tested-by: Breno Leitao Acked-by: Catalin Marinas Acked-by: Rob Herring (Arm) Acked-by: Baoquan He Acked-by: Mike Rapoport (Microsoft) Acked-by: Ard Biesheuvel Signed-off-by: Jinjie Ruan Link: https://patch.msgid.link/20260629094746.191843-10-ruanjinjie@huawei.com Signed-off-by: Mike Rapoport (Microsoft)

Merge tag 'memblock-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

2026-04-18T18:29:14+00:00

Pull memblock updates from Mike Rapoport: - improve debuggability of reserve_mem kernel parameter handling with print outs in case of a failure and debugfs info showing what was actually reserved - Make memblock_free_late() and free_reserved_area() use the same core logic for freeing the memory to buddy and ensure it takes care of updating memblock arrays when ARCH_KEEP_MEMBLOCK is enabled. * tag 'memblock-v7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: x86/alternative: delay freeing of smp_locks section memblock: warn when freeing reserved memory before memory map is initialized memblock, treewide: make memblock_free() handle late freeing memblock: make free_reserved_area() update memblock if ARCH_KEEP_MEMBLOCK=y memblock: extract page freeing from free_reserved_area() into a helper memblock: make free_reserved_area() more robust mm: move free_reserved_area() to mm/memblock.c powerpc: opal-core: pair alloc_pages_exact() with free_pages_exact() powerpc: fadump: pair alloc_pages_exact() with free_pages_exact() memblock: reserve_mem: fix end caclulation in reserve_mem_release_by_name() memblock: move reserve_bootmem_range() to memblock.c and make it static memblock: Add reserve_mem debugfs info memblock: Print out errors on reserve_mem parser

arm64,ppc64le/kdump: pass dm-crypt keys to kdump kernel

2026-04-03T06:36:24+00:00

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 userspace. Link: https://lkml.kernel.org/r/20260225060347.718905-4-coxu@redhat.com Link: https://lore.kernel.org/all/20250502011246.99238-1-coxu@redhat.com/ [1] Link: https://github.com/devicetree-org/dt-schema/pull/181 [2] Signed-off-by: Coiby Xu Acked-by: Rob Herring (Arm) Reviewed-by: Sourabh Jain Cc: Arnaud Lefebvre Cc: Baoquan he Cc: Dave Young Cc: Kairui Song Cc: Pingfan Liu Cc: Krzysztof Kozlowski Cc: Thomas Staudt Cc: Will Deacon Cc: Christophe Leroy (CS GROUP) Signed-off-by: Andrew Morton

memblock, treewide: make memblock_free() handle late freeing

2026-04-01T08:20:15+00:00

It shouldn't be responsibility of memblock users to detect if they free memory allocated from memblock late and should use memblock_free_late(). Make memblock_free() and memblock_phys_free() take care of late memory freeing and drop memblock_free_late(). Link: https://patch.msgid.link/20260323074836.3653702-9-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft)

of/kexec: refactor ima_get_kexec_buffer() to use ima_validate_range()

2026-01-27T03:07:11+00:00

Refactor the OF/DT ima_get_kexec_buffer() to use a generic helper to validate the address range. No functional change intended. Link: https://lkml.kernel.org/r/20251231061609.907170-3-harshit.m.mogalapalli@oracle.com Signed-off-by: Harshit Mogalapalli Reviewed-by: Mimi Zohar Cc: Alexander Graf Cc: Ard Biesheuvel Cc: Baoquan He Cc: Borislav Betkov Cc: guoweikang Cc: Henry Willard Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jiri Bohac Cc: Joel Granados Cc: Jonathan McDowell Cc: Mike Rapoport Cc: Paul Webb Cc: Sohil Mehta Cc: Sourabh Jain Cc: Thomas Gleinxer Cc: Yifei Liu Cc: Signed-off-by: Andrew Morton

arm64: add KHO support

2025-05-13T06:50:41+00:00

We now have all bits in place to support KHO kexecs. Add awareness of KHO in the kexec file as well as boot path for arm64 and adds the respective kconfig option to the architecture so that it can use KHO successfully. Changes to the "chosen" node have been sent to https://github.com/devicetree-org/dt-schema/pull/158. Link: https://lkml.kernel.org/r/20250509074635.3187114-10-changyuanl@google.com Signed-off-by: Alexander Graf Co-developed-by: Mike Rapoport (Microsoft) Signed-off-by: Mike Rapoport (Microsoft) Co-developed-by: Changyuan Lyu Signed-off-by: Changyuan Lyu Cc: Andy Lutomirski Cc: Anthony Yznaga Cc: Arnd Bergmann Cc: Ashish Kalra Cc: Ben Herrenschmidt Cc: Borislav Betkov Cc: Catalin Marinas Cc: Dave Hansen Cc: David Woodhouse Cc: Eric Biederman Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: James Gowans Cc: Jason Gunthorpe Cc: Jonathan Corbet Cc: Krzysztof Kozlowski Cc: Marc Rutland Cc: Paolo Bonzini Cc: Pasha Tatashin Cc: Peter Zijlstra Cc: Pratyush Yadav Cc: Rob Herring Cc: Saravana Kannan Cc: Stanislav Kinsburskii Cc: Steven Rostedt Cc: Thomas Gleinxer Cc: Thomas Lendacky Cc: Will Deacon Signed-off-by: Andrew Morton

of/fdt: add dt_phys arg to early_init_dt_scan and early_init_dt_verify

2024-10-29T20:32:45+00:00

__pa() is only intended to be used for linear map addresses and using it for initial_boot_params which is in fixmap for arm64 will give an incorrect value. Hence save the physical address when it is known at boot time when calling early_init_dt_scan for arm64 and use it at kexec time instead of converting the virtual address using __pa(). Note that arm64 doesn't need the FDT region reserved in the DT as the kernel explicitly reserves the passed in FDT. Therefore, only a debug warning is fixed with this change. Reported-by: Breno Leitao Suggested-by: Mark Rutland Signed-off-by: Usama Arif Fixes: ac10be5cdbfa ("arm64: Use common of_kexec_alloc_and_setup_fdt()") Link: https://lore.kernel.org/r/20241023171426.452688-1-usamaarif642@gmail.com Signed-off-by: Rob Herring (Arm)

arm64, crash: wrap crash dumping code into crash related ifdefs

2024-02-24T01:48:23+00:00

Now crash codes under kernel/ folder has been split out from kexec code, crash dumping can be separated from kexec reboot in config items on arm64 with some adjustments. Here wrap up crash dumping codes with CONFIG_CRASH_DUMP ifdeffery. [bhe@redhat.com: fix building error in generic codes] Link: https://lkml.kernel.org/r/20240129135033.157195-2-bhe@redhat.com Link: https://lkml.kernel.org/r/20240124051254.67105-8-bhe@redhat.com Signed-off-by: Baoquan He Cc: Al Viro Cc: Eric W. Biederman Cc: Hari Bathini Cc: Pingfan Liu Cc: Klara Modin Cc: Michael Kelley Cc: Nathan Chancellor Cc: Stephen Rothwell Cc: Yang Li Signed-off-by: Andrew Morton

mm,ima,kexec,of: use memblock_free_late from ima_free_kexec_buffer

2023-08-18T16:47:45+00:00

The code calling ima_free_kexec_buffer runs long after the memblock allocator has already been torn down, potentially resulting in a use after free in memblock_isolate_range. With KASAN or KFENCE, this use after free will result in a BUG from the idle task, and a subsequent kernel panic. Switch ima_free_kexec_buffer over to memblock_free_late to avoid that issue. Fixes: fee3ff99bc67 ("powerpc: Move arch independent ima kexec functions to drivers/of/kexec.c") Cc: stable@kernel.org Signed-off-by: Rik van Riel Suggested-by: Mike Rappoport Link: https://lore.kernel.org/r/20230817135759.0888e5ef@imladris.surriel.com Signed-off-by: Rob Herring

of/kexec: Fix reading 32-bit "linux,initrd-{start,end}" values

2022-12-06T20:50:36+00:00

"linux,initrd-start" and "linux,initrd-end" can be 32-bit values even on a 64-bit platform. Ideally, the size should be based on '#address-cells', but that has never been enforced in the kernel's FDT boot parsing code (early_init_dt_check_for_initrd()). Bootloader behavior is known to vary. For example, kexec always writes these as 64-bit. The result of incorrectly reading 32-bit values is most likely the reserved memory for the original initrd will still be reserved for the new kernel. The original arm64 equivalent of this code failed to release the initrd reserved memory in *all* cases. Use of_read_number() to mirror the early_init_dt_check_for_initrd() code. Fixes: b30be4dc733e ("of: Add a common kexec FDT setup function") Cc: stable@vger.kernel.org Reported-by: Peter Maydell Link: https://lore.kernel.org/r/20221128202440.1411895-1-robh@kernel.org Signed-off-by: Rob Herring