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

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

[Mike Rapoport]

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@huawei.com/
> 
> 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.

>   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
> 

-- 
Sincerely yours,
Mike.