[PATCH 9/9] integrity: check properly whether EFI GetVariable() is available

[Ard Biesheuvel]

On Wed, 19 Feb 2020 at 21:46, Serge E. Hallyn <serge at hallyn.com> wrote:
>
> On Wed, Feb 19, 2020 at 06:19:07PM +0100, Ard Biesheuvel wrote:
> > Testing the value of the efi.get_variable function pointer is not
> > the right way to establish whether the platform supports EFI
> > variables at runtime. Instead, use the newly added granular check
> > that can test for the presence of each EFI runtime service
> > individually.
> >
> > Cc: James Morris <jmorris at namei.org>
> > Cc: "Serge E. Hallyn" <serge at hallyn.com>
> > Cc: linux-security-module at vger.kernel.org
> > Signed-off-by: Ard Biesheuvel <ardb at kernel.org>
> > ---
> >  security/integrity/platform_certs/load_uefi.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
> > index 111898aad56e..e2fe1bd3abb9 100644
> > --- a/security/integrity/platform_certs/load_uefi.c
> > +++ b/security/integrity/platform_certs/load_uefi.c
> > @@ -76,7 +76,7 @@ static int __init load_uefi_certs(void)
> >       unsigned long dbsize = 0, dbxsize = 0, moksize = 0;
> >       int rc = 0;
> >
> > -     if (!efi.get_variable)
> > +     if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE))
>
> Sorry, where is this defined?
>

Apologies, I failed to cc everyone on the whole series.

It is defined in the first patch.

https://lore.kernel.org/linux-efi/20200219171907.11894-1-ardb@kernel.org/