Re: [PATCH 1/1] x86/power: only verify usable RAM regions during hibernation E820 check

[Milan Oravec <moravec@ukf.sk>]

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Hallo, thank you very much! This patch resolves this issue on my HP 
OmniBook X Flip - hibernation is working again.

Best regards,

Milan Oravec

CIKT UKF Nitra
Mobil/Signal: +421907670270
email: moravec@ukf.sk

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On 6/20/26 10:15, Marco Scardovi wrote:
> On some UEFI platforms (such as the HP OmniBook X Flip), resuming from
> hibernation fails with 'Hibernate inconsistent memory map detected!'
> even though the usable system RAM configuration is identical.
>
> This happens because the UEFI firmware or bootloader (like GRUB) makes
> non-deterministic allocations or shifts reserved/ACPI memory regions
> dynamically across boots, which changes the CRC32 checksum computed
> over the entire E820 table (which includes non-RAM types like reserved,
> ACPI, NVS, and unusable memory).
>
> Fix this by modifying compute_e820_crc32() to only calculate the
> checksum over memory map entries of type E820_TYPE_RAM. Usable system
> RAM layout is still verified to ensure data safety, but dynamic shifts
> in ACPI and other reserved ranges are ignored.
>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221569
> Fixes: f5d1499ae209 ("PM: hibernate: x86: Use crc32 instead of md5 for hibernation e820 integrity check")
> Assisted-by: Antigravity:gemini-3.5-flash
> Signed-off-by: Marco Scardovi <scardracs@disroot.org>
> ---
>   arch/x86/power/hibernate.c | 15 +++++++++++----
>   1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/power/hibernate.c b/arch/x86/power/hibernate.c
> index a2294c1649f6..752a490bc3d2 100644
> --- a/arch/x86/power/hibernate.c
> +++ b/arch/x86/power/hibernate.c
> @@ -70,12 +70,19 @@ struct restore_data_record {
>    *
>    * Return: the resulting checksum
>    */
> -static inline u32 compute_e820_crc32(struct e820_table *table)
> +static u32 compute_e820_crc32(struct e820_table *table)
>   {
> -	int size = offsetof(struct e820_table, entries) +
> -		sizeof(struct e820_entry) * table->nr_entries;
> +	u32 crc = ~0;
> +	int i;
> +
> +	for (i = 0; i < table->nr_entries; i++) {
> +		if (table->entries[i].type == E820_TYPE_RAM) {
> +			crc = crc32_le(crc, (unsigned char const *)&table->entries[i],
> +				       sizeof(struct e820_entry));
> +		}
> +	}
>   
> -	return ~crc32_le(~0, (unsigned char const *)table, size);
> +	return ~crc;
>   }
>   
>   #ifdef CONFIG_X86_64

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