[PATCH v2] x86/hibernate: Ignore page-zero RAM in E820 checksum

[sashiko-bot at kernel.org]

> The legacy kexec_load path reconstructs the E820 map exported through
> sysfs.  kexec-tools leaves the first 1 KiB unavailable for the real-mode
> transition, so a kernel entered through kexec_load can see conventional
> RAM starting at 0x400.  A subsequent firmware boot reports the same RAM
> range starting at zero.
> 
> The hibernation E820 checksum compares those byte representations and
> rejects the image, even though the maps agree from page one onwards.
> A QEMU guest showed this transition:
> 
>   firmware:     RAM [0-0x9fbff]
>   kexec_load:   gap [0-0x3ff], RAM [0x400-0x9fbff]
>   firmware:     RAM [0-0x9fbff]
> 
> The checksum covers e820_table_firmware, which trim_bios_range() leaves
> [ ... ]
> kernel carries on.
> 
> Fixes: 62a03defeabd ("PM / hibernate: Verify the consistent of e820 memory map by md5 digest")
> Reported-by: Roberto Ricci <io at r-ricci.it>
> Signed-off-by: Matthias Goergens <matthias.goergens at gmail.com>

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

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260926052117.3613637-1-matthias.goergens@gmail.com?part=1