On 5/25/2026 6:14 PM, Huacai Chen wrote:
> Hi, Jinjie,
>
> On Mon, May 25, 2026 at 4:50 PM Jinjie Ruan <[email protected]> wrote:
>>
>> The crash memory allocation, and the exclude of crashk_res, crashk_low_res
>> and crashk_cma memory are almost identical across different architectures,
>> This patch set handle them in crash core in a general way, which eliminate
>> a lot of duplication code.
>>
>> And add support for crashkernel CMA reservation for arm64 and riscv.
>>
>> Also add support for arm64 crash hotplug.
>>
>> This patch set is rebased on v7.1-rc1.
>>
>> Basic second kernel boot test were performed on QEMU platforms for x86,
>> ARM64 and RISC-V architectures with the following parameters:
>>
>> "cma=256M crashkernel=4G crashkernel=64M,cma"
>>
>> For first kernel, there will be such log:
>>
>> # dmesg | grep crash
>> [ 0.000000] crashkernel low memory reserved: 0xe8000000 -
>> 0xf0000000 (128 MB)
>> [ 0.000000] crashkernel reserved: 0x000000023e600000 -
>> 0x000000033e600000 (4096 MB)
>> [ 0.000000] crashkernel CMA reserved: 64 MB in 1 ranges
>>
>> # dmesg | grep cma
>> [ 0.000000] cma: Reserved 256 MiB at 0x00000000f0000000
>> [ 0.000000] cma: Reserved 64 MiB at 0x0000000100000000
>>
>> For second kernel, there will be such log:
>>
>> [ 0.000000] OF: fdt: Looking for usable-memory-range property...
>> [ 0.000000] OF: fdt: cap_mem_regions[0]: base=0x000000023e600000,
>> size=0x0000000100000000
>> [ 0.000000] OF: fdt: cap_mem_regions[1]: base=0x00000000e8000000,
>> size=0x0000000008000000
>> [ 0.000000] OF: fdt: cap_mem_regions[2]: base=0x0000000100000000,
>> size=0x0000000004000000
>>
>> Changes in v14:
>> - Fix image->elf_headers memory leak during retry loop for arm64 as Sashiko
>> AI code review pointed out.
>> - Solve the hotplug notifier arch_crash_handle_hotplug_event() AA
>> self-deadlock problem as Sashiko AI code review pointed out.
>> - Fix the TOCTOU issue in prepare_elf_headers() by get_online_mems().
>> - -ENOMEM -> -EAGAIN as Breno suggested.
>> - Add support for arm64 crash hotplug.
>> - Link to v13:
>> https://lore.kernel.org/all/[email protected]/
>>
>> Changes in v13:
>> - Rebased on v7.1-rc1.
>> - Update the commit message.
>> - Add Reviewed-by.
>> - Link to v12:
>> https://lore.kernel.org/all/[email protected]/
>>
>> Changes in v12:
>> - Remove the unused "nr_mem_ranges" for x86.
>> - Add "Fix crashk_low_res not exclude bug" test log.
>> - Provide a separate patch for each architecture for using
>> crash_prepare_headers(), which will make the review more convenient.
>> - Add Reviewed-by and Tested-by.
>> - Link to v11:
>> https://lore.kernel.org/all/[email protected]/
>>
>> Changes in v11:
>> - Avoid silently drop crash memory if the crash kernel is built without
>> CONFIG_CMA.
>> - Remove unnecessary "cmem->nr_ranges = 0" for arch_crash_populate_cmem()
>> as we use kvzalloc().
>> - Provide a separate patch for each architecture to fix the existing
>> buffer overflow issue.
>> - Add Acked-bys for arm64.
>>
>> Changes in v10:
>> - Fix crashk_low_res not excluded bug in the existing
>> RISC-V code.
>> - Fix an existing memory leak issue in the existing PowerPC code.
>> - Fix the ordering issue of adding CMA ranges to
>> "linux,usable-memory-range".
>> - Fix an existing concurrency issue. A Concurrent memory hotplug may occur
>> between reading memblock and attempting to fill cmem during kexec_load()
>> for almost all existing architectures.
>> - Link to v9:
>> https://lore.kernel.org/all/[email protected]/
>>
>> Changes in v9:
>> - Collect Reviewed-by and Acked-by, and prepare for Sashiko AI review.
>> - Link to v8:
>> https://lore.kernel.org/all/[email protected]/
>>
>> Changes in v8:
>> - Fix the build issues reported by kernel test robot and Sourabh.
>> - Link to v7:
>> https://lore.kernel.org/all/[email protected]/
>>
>> Changes in v7:
>> - Correct the inclusion of CMA-reserved ranges for kdump kernel in of/kexec
>> for arm64 and riscv.
>> - Add Acked-by.
>> - Link to v6:
>> https://lore.kernel.org/all/[email protected]/
>>
>> Changes in v6:
>> - Update the crash core exclude code as Mike suggested.
>> - Rebased on v7.0-rc1.
>> - Add acked-by.
>> - Link to v5:
>> https://lore.kernel.org/all/[email protected]/
>>
>> Jinjie Ruan (16):
>> riscv: kexec_file: Fix crashk_low_res not exclude bug
>> powerpc/crash: Fix possible memory leak in update_crash_elfcorehdr()
>> arm64: kexec: Fix image->elf_headers memory leak during retry loop
>> x86/kexec: Fix potential buffer overflow in prepare_elf_headers()
>> arm64: kexec_file: Fix potential buffer overflow in
>> prepare_elf_headers()
>> riscv: kexec_file: Fix potential buffer overflow in
>> prepare_elf_headers()
>> LoongArch: kexec: Fix potential buffer overflow in
>> prepare_elf_headers()
>> crash: Add crash_prepare_headers() to exclude crash kernel memory
>> arm64: kexec_file: Use crash_prepare_headers() helper to simplify code
>> x86/kexec: Use crash_prepare_headers() helper to simplify code
>> riscv: kexec_file: Use crash_prepare_headers() helper to simplify code
>> LoongArch: kexec: Use crash_prepare_headers() helper to simplify code
>> crash: Use crash_exclude_core_ranges() on powerpc
>> arm64: kexec: Add support for crashkernel CMA reservation
>> riscv: kexec: Add support for crashkernel CMA reservation
>> arm64/crash: Add crash hotplug support
> I have some bikesheedings about the subjects. Can we unify the prefix formats?
> x86/kexec, arm64: kexec_file, riscv: kexec_file, LoongArch: kexec .....
>
> Huacai
Sure, will update it in next version.
>
>>
>> Sourabh Jain (1):
>> powerpc/crash: sort crash memory ranges before preparing elfcorehdr
>>
>> .../admin-guide/kernel-parameters.txt | 16 +--
>> arch/arm64/Kconfig | 3 +
>> arch/arm64/include/asm/kexec.h | 14 +-
>> arch/arm64/kernel/Makefile | 1 +
>> arch/arm64/kernel/crash.c | 125 ++++++++++++++++++
>> arch/arm64/kernel/kexec_image.c | 22 ++-
>> arch/arm64/kernel/machine_kexec_file.c | 78 ++++++-----
>> arch/arm64/mm/init.c | 5 +-
>> arch/loongarch/kernel/machine_kexec_file.c | 43 +++---
>> arch/powerpc/include/asm/kexec_ranges.h | 1 -
>> arch/powerpc/kexec/crash.c | 7 +-
>> arch/powerpc/kexec/ranges.c | 101 +-------------
>> arch/riscv/kernel/machine_kexec_file.c | 42 +++---
>> arch/riscv/mm/init.c | 5 +-
>> arch/x86/kernel/crash.c | 92 ++-----------
>> drivers/of/fdt.c | 9 +-
>> drivers/of/kexec.c | 9 ++
>> include/linux/crash_core.h | 11 ++
>> include/linux/crash_reserve.h | 4 +-
>> kernel/crash_core.c | 102 +++++++++++++-
>> 20 files changed, 392 insertions(+), 298 deletions(-)
>> create mode 100644 arch/arm64/kernel/crash.c
>>
>> --
>> 2.34.1
>>
>
