Re: [PATCH 0/8] arm64: crash: Add crash hotplug support

[Jinjie Ruan]

在 2026/7/26 15:10, Mike Rapoport 写道:
> Hi Jinjie,
> 
> On Thu, Jul 23, 2026 at 09:12:34PM +0800, Jinjie Ruan wrote:
>> When CPU or memory hotplug events occur, the elfcorehdr in the kdump image
>> becomes stale, potentially leading to incomplete crash dumps.
>>
>> Currently, userspace udev rules reload the entire kdump image upon such
>> events, which is inefficient and leaves kdump inactive for a long time.
>>
>> Commit 247262756121 ("crash: add generic infrastructure for crash hotplug
>> support") introduced a kernel mechanism to update only the elfcorehdr.
>> This patch set implements crash hotplug support for arm64.
>>
>> It also addresses and fixes several critical pre-existing code issues
>> and Sashiko AI review findings extracted from the previous patch set,
>> following Baoquan's suggestions.
>>
>> The major improvements and fixes included in this series are:
>>
>> - Fix powerpc memory leak, null-ptr-def and overlapping memory
>>   range truncation bug.
>>
>> - Fix several memory leaks for arm64.
>>
>> - Simplify arm64 load_other_segments().
>>
>> - Implement infrastructure for arm64 crash memory hotplug support.
>>
>> This patch set is rebased on liveupdate/crashkernel-cma.
>>
>> Link: https://lore.kernel.org/all/20260601094805.2928614-1-ruanjinjie@xxxxxxxxxx/
>>
>> Jinjie Ruan (8):
>>   powerpc/crash: Fix possible memory leak in update_crash_elfcorehdr()
>>   powerpc/kexec_file: Fix null-ptr-def in extra size calculation
>>   powerpc/kexec_file: Prevent kexec range truncation
> 
> It's weird to see powerpc fixes in a series that adds a feature for arm64.
> Judging by the subjects, they are completely unrelated to to crash support
> for hotplug and should be sent as a separate set.

Hi Mike,

You are right, I'll rebase and post v2 shortly, and send the powerpc
fixes as a standalone series.

> 
>>   kexec: Extract kexec_free_segment_cma() from kimage_free_cma()
>>   arm64: kexec_file: Fix CMA page leaks in segment placement retry loops
>>   arm64: kexec_file: Fix image->elf_headers memory leak during retry
>>     loop
>>   arm64: kexec_file: Simplify load_other_segments()
>>   arm64: crash: Add crash hotplug support
>>
>>  arch/arm64/Kconfig                     |   3 +
>>  arch/arm64/include/asm/kexec.h         |  13 +++
>>  arch/arm64/kernel/Makefile             |   2 +-
>>  arch/arm64/kernel/crash.c              | 148 +++++++++++++++++++++++++
>>  arch/arm64/kernel/kexec_image.c        |   1 +
>>  arch/arm64/kernel/machine_kexec_file.c |  76 ++++++-------
>>  arch/powerpc/kexec/crash.c             |   2 +-
>>  arch/powerpc/kexec/file_load_64.c      |   2 +-
>>  arch/powerpc/kexec/ranges.c            |  12 +-
>>  include/linux/kexec.h                  |   2 +
>>  kernel/kexec_core.c                    |  25 +++--
>>  11 files changed, 223 insertions(+), 63 deletions(-)
>>  create mode 100644 arch/arm64/kernel/crash.c
>>
>> -- 
>> 2.34.1
>>
>