[PATCH v3 00/11] kdump: reduce vmcore size and capture time

[Wandun]

On 6/11/26 10:09, Wandun wrote:
> 
> 
> On 5/27/26 11:29, Wandun Chen wrote:
>> From: Wandun Chen <chenwandun at lixiang.com>
>>
>> On SoCs that carve out large firmware-owned reserved memory (GPU
>> firmware, DSP, modem, camera ISP, NPU, ...), kdump currently dumps
>> those carveouts as part of system RAM even though their contents are
>> firmware state that is not useful for kernel crash analysis.
>>
>> This series introduces an opt-in 'dumpable' flag [1] on struct
>> reserved_mem and uses it to filter the elfcorehdr PT_LOAD ranges on
>> DT-based architectures (arm64, riscv, loongarch). By default reserved
>> regions are treated as non-dumpable; CMA regions are explicitly opted
>> in because their pages are returned to the buddy allocator and may
>> carry key crash-analysis data.
>>
>> The series is organized as follows:
>> Patches 1-3: Pre-existing fixes and a small prep change.
>> Patches 4-5: Restructure to allow appending /memreserve/ entries.
>> Patches 6-7: Add a dumpable flag and append /memreserve/ entries.
>> Patch 8: Add generic kdump helpers.
>> Patches 9-11: Wire the helpers into arm64, riscv and loongarch kdump
>>                elfcorehdr preparation.
> Hi,
> 
> Gentle ping on this series.
> 
> Status summary:
> -patch 03: respun separately per Rob's suggestion, picked up for 7.2
> -patch 06: Acked-by: Marek Szyprowski -patch 09: Acked-by: Will Deacon
> The remaining patches (01, 02, 04, 05, 07, 08, 10, 11) are still
> awaiting review. your feedback would be greately appreciated. I know we
> are at the end of 7.1 -rc cycle, I don't want to rush this series, just
> collecting more feedback, and will send next version based on 7.2-rc1.
> If spliting the series into smaller logical group would make review
> easier, please let me know. Best regards, Wandun

Apologies for the formatting issue in my previous email.
Here is the properly formatted version.

Gentle ping on this series.

Status summary:
- patch 03: respun separately per Rob's suggestion, picked up for 7.2
- patch 06: Acked-by: Marek Szyprowski
- patch 09: Acked-by: Will Deacon

The remaining patches (01, 02, 04, 05, 07, 08, 10, 11) are still
awaiting review. Your feedback would be greatly appreciated.

I know we are at the end of 7.1-rc cycle, I don't want to rush this
series, just collecting more feedback, and will send next version based
on 7.2-rc1.

If splitting the series into smaller logical groups would make review
easier, please let me know.

Best regards,
Wandun


>>
>> v2 --> v3:
>> 1. Fix out-of-bounds issue if device tree lacks /reserved-memory node.[2]
>> 2. Fix UAF issue when alloc_reserved_mem_array() fails.
>> 3. Add some prepare patches.
>>
>> v1 --> v2:
>> 1. v1 added an opt-out DT property ('linux,no-dump'). Per Rob's
>>     feedback [1], v2 drop that property and exclude reserve memory
>>     by default.
>> 2. Split some prepared patches from the original patches.
>> 3. Address coding-style comments on patch 5 from Rob.
>>
>> [1] https://lore.kernel.org/lkml/20260506144542.GA2072596-
>> robh at kernel.org/
>> [2] https://sashiko.dev/#/patchset/20260520091844.592753-1-
>> chenwandun%40lixiang.com?part=4
>>
>> Wandun Chen (11):
>>    of: reserved_mem: handle NULL name in of_reserved_mem_lookup()
>>    kexec/crash: provide crash_exclude_mem_range() stub when
>>      CONFIG_CRASH_DUMP=n
>>    of: reserved_mem: avoid post-init UAF when alloc_reserved_mem_array()
>>      fails
>>    of: reserved_mem: zero total_reserved_mem_cnt if no valid
>>      /reserved-memory entry
>>    of: reserved_mem: split alloc_reserved_mem_array() from
>>      fdt_scan_reserved_mem_late()
>>    of: reserved_mem: add dumpable flag to opt-in vmcore
>>    of: reserved_mem: save /memreserve/ entries into the reserved_mem
>>      array
>>    of: reserved_mem: add kdump helpers to exclude non-dumpable regions
>>    arm64: kdump: exclude non-dumpable reserved memory regions from vmcore
>>    riscv: kdump: exclude non-dumpable reserved memory regions from vmcore
>>    loongarch: kdump: exclude non-dumpable reserved memory regions from
>>      vmcore
>>
>>   arch/arm64/kernel/machine_kexec_file.c     |   6 ++
>>   arch/loongarch/kernel/machine_kexec_file.c |   6 ++
>>   arch/riscv/kernel/machine_kexec_file.c     |   4 +
>>   drivers/of/fdt.c                           |  11 +-
>>   drivers/of/of_private.h                    |   3 +
>>   drivers/of/of_reserved_mem.c               | 117 +++++++++++++++++++--
>>   include/linux/crash_core.h                 |   6 ++
>>   include/linux/of_reserved_mem.h            |  15 +++
>>   kernel/dma/contiguous.c                    |   1 +
>>   9 files changed, 157 insertions(+), 12 deletions(-)
>>
>