RE: [PATCH 1/1 v9] use crc32 instead of md5 for hibernation e820 integrity check

[Dexuan Cui]

> From: Chris von Recklinghausen 
> Sent: Friday, April 16, 2021 6:17 AM
>  ...
> Hibernation fails on a system in fips mode because md5 is used for the e820
> integrity check and is not available. Use crc32 instead.
> 
> The check is intended to detect whether the E820 memory map provided
> by the firmware after cold boot unexpectedly differs from the one that
> was in use when the hibernation image was created. In this case, the
> hibernation image cannot be restored, as it may cover memory regions
> that are no longer available to the OS.
> 
> A non-cryptographic checksum such as CRC-32 is sufficient to detect such
> inadvertent deviations.
> 
> Fixes: 62a03defeabd ("PM / hibernate: Verify the consistent of e820 memory
> map
>by md5 digest")
> 
> Signed-off-by: Chris von Recklinghausen 
> ---

Tested-by: Dexuan Cui 
Reviewed-by: Dexuan Cui 

Thanks Chris and all for the patch!

Re: [PATCH 1/1 v9] use crc32 instead of md5 for hibernation e820 integrity check

[Eric Biggers]

On Fri, Apr 16, 2021 at 09:16:55AM -0400, Chris von Recklinghausen wrote:
> Hibernation fails on a system in fips mode because md5 is used for the e820
> integrity check and is not available. Use crc32 instead.

Doesn't the commit title need to be prefixed with something like "x86/power"?

> The check is intended to detect whether the E820 memory map provided
> by the firmware after cold boot unexpectedly differs from the one that
> was in use when the hibernation image was created. In this case, the
> hibernation image cannot be restored, as it may cover memory regions
> that are no longer available to the OS.
> 
> A non-cryptographic checksum such as CRC-32 is sufficient to detect such
> inadvertent deviations.
> 
> Fixes: 62a03defeabd ("PM / hibernate: Verify the consistent of e820 memory map
>by md5 digest")

The "Fixes" line shouldn't be line-wrapped.

Otherwise this looks fine.  The explanation in the commit message still isn't
great, but it's much better than it was before.

You can add:

Reviewed-by: Eric Biggers 

- Eric