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

[Rob Herring <robh@kernel.org>]

On Wed, May 27, 2026 at 11:29:06AM +0800, Wandun Chen wrote:
> From: Wandun Chen <chenwandun@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.
> 
> 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@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()

>   of: reserved_mem: zero total_reserved_mem_cnt if no valid
>     /reserved-memory entry

I applied these 2 for 7.2.

Rob