Re: [PATCH v7 3/9] crash_core: serialize crash header preparation against hotplug

[sashiko-bot]

> From: Wandun Chen <chenwandun@xxxxxxxxxxx>
> 
> crash_prepare_headers() counts memory ranges before populating the
> allocated crash_mem array. The weak implementation used by ARM64,
> RISC-V and LoongArch walks memblock.memory, while x86 performs the same
> two-pass operation over system RAM resources. Concurrent memory hotplug
> can change range source between the two walks and make the populate
> pass overflow cmem->ranges.
> 
> Take device_hotplug_lock when preparing crash headers during
> kexec_file_load(). The x86 memory hotplug path already takes
> device_hotplug_lock, so call __crash_prepare_headers() directly
> to avoid recursive locking.
> 
> Sashiko reported this issue in [1].
> 
> Fixes: 3751e728cef2 ("arm64: kexec_file: add crash dump support")
> Fixes: 1bcca8620a91 ("LoongArch: Add crash dump support for kexec_file")
> Fixes: 8acea455fafa ("RISC-V: Support for kexec_file on panic")
> Fixes: dd5f726076cc ("kexec: support for kexec on panic using new system call")
> Signed-off-by: Wandun Chen <chenwandun@xxxxxxxxxxx>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260922084256.1515554-1-chenwandun1@xxxxxxxxx?part=3