Re: [PATCH] efi: Make EFI_VARS_PSTORE depend on EFIVAR_FS

[Theodore Tucker <theodore@tti0.net>]

Hi,

On 20/08/2026 12:49, Ard Biesheuvel wrote:
> 
> Actually, EFI pstore does not depend on efivarfs, it only depends on
> the efivars layer.
> 
> Why do you think it needs to depend on EFIVAR_FS?

When building a 7.0 kernel for x86 with `make alldefconfig` and then 
enabling CONFIG_EFI, CONFIG_PSTORE, and CONFIG_EFI_VARS_PSTORE, I found 
that the EFI pstore backend failed to register 
(/sys/module/pstore/parameters/backend was empty after boot) unless 
CONFIG_EFIVAR_FS had also been enabled explicitly.

I can see now that EFI pstore code should not need the efivarfs, and 
neither should userspace, since it gets access to any logs through 
/sys/fs/pstore. So I do appreciate that my patch may not be the right 
fix here, and I proposed it not as an expert on the internals of EFI 
pstore, but from experimentation as a user. Sorry for the noise.

I eventually ended up using the ramoops pstore backend so unfortunately 
no longer have the exact kernel configurations I used when this tripped 
me up.

Thanks and kind regards,

Theodore


-- 
Theodore Tucker
theodore@tti0.net