(cc Matthew and Peter)
On Wed, 17 Mar 2021 at 08:35, Heinrich Schuchardt <xypron.glpk@xxxxxx> wrote:
>
>
> Hello Ard,
>
> in efivar_init() I read:
>
> /*
> * Per EFI spec, the maximum storage allocated for both
> * the variable name and variable data is 1024 bytes.
> */
>
> do {
> variable_name_size = 1024;
>
> This dates back at least to Linux 2.5.0 of 23-Nov-2001 where in
> arch/ia64/kernel/efivars.c we have:
>
> /*
> * The maximum size of VariableName + Data = 1024
> * Therefore, it's reasonable to save that much
> * space in each part of the structure,
> * and we use a page for reading/writing.
> */
>
> I cannot find this 1024 byte size limit neither in UEFI spec 2.8B nor in
> EFI spec 1.1.
>
> Variable d719b2cb-3d3a-4596-a3bc-dad00e67656f-db has 5080 bytes of data
> on my laptop.
>
> It may not reasonable to use a variable name exceeding 512 UTF-16
> characters. But shouldn't we handle this case gracefully in efivar_init()?
>
This predates my involvement in EFI by a long time, so I've cc'ed
Peter and Matthew, who may be able to shed some light on this.
