linux-kernel - Re: [PATCH] efivarfs: fix abnormal GUID in variable name by using strcpy to replace null with dash

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Date:	Thu, 07 Mar 2013 13:57:43 +0000
From:	Matt Fleming <matt@...sole-pimps.org>
To:	joeyli <jlee@...e.com>
Cc:	linux-efi@...r.kernel.org, linux-kernel@...r.kernel.org,
	Michael Schroeder <mls@...e.com>,
	Josh Boyer <jwboyer@...hat.com>,
	Peter Jones <pjones@...hat.com>,
	Matthew Garrett <mjg59@...f.ucam.org>,
	Frederic Crozat <fcrozat@...e.com>
Subject: Re: [PATCH] efivarfs: fix abnormal GUID in variable name by using
 strcpy to replace null with dash

On Thu, 2013-03-07 at 11:39 +0000, Matt Fleming wrote:
> On Thu, 2013-03-07 at 18:34 +0800, joeyli wrote:
> > The VariableNameSize is not reliable when EFI_SUCCESS is returned
> > because UEFI 2.3.1 spec only mention VariableNameSize should updated
> > when EFI_BUFFER_TOO_SMALL is returned. And, the 1024 bytes of buffer is
> > from old UEFI spec. There doesn't have any size condition of variable
> > data or variable name in 2.3.1 spec.
> 
> The spec may only mention what happens in the EFI_BUFFER_TOO_SMALL case,
> but for EFI_SUCCESS, any behaviour other than leaving VariableNameSize
> alone or updating it with the required size of the buffer is just
> completely insane.
> 
> > I modified the patch to grab VariableNameSize when EFI_BUFFER_TOO_SMALL,
> > the behavior like what we do in efivarfs_file_read().
> 
> Thanks, this does seem like the most robust solution.

Also, you're probably going to need to update
efivar_update_sysfs_entries() too.

-- 
Matt Fleming, Intel Open Source Technology Center

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