[PATCH 1/2] lib: fwts_uefi: add the function to check the efivars interface existence

[IvanHu]

On 05/17/2013 04:46 PM, Colin Ian King wrote:
> On 17/05/13 03:59, IvanHu wrote:
>> On 05/16/2013 05:33 PM, Colin Ian King wrote:
>>> On 16/05/13 09:34, Ivan Hu wrote:
>>>> Signed-off-by: Ivan Hu <ivan.hu at canonical.com>
>>>> ---
>>>>    src/lib/include/fwts_uefi.h |    2 ++
>>>>    src/lib/src/fwts_uefi.c     |   12 ++++++++++++
>>>>    2 files changed, 14 insertions(+)
>>>>
>>>> diff --git a/src/lib/include/fwts_uefi.h b/src/lib/include/fwts_uefi.h
>>>> index 98eddb0..c0a6ce5 100644
>>>> --- a/src/lib/include/fwts_uefi.h
>>>> +++ b/src/lib/include/fwts_uefi.h
>>>> @@ -356,4 +356,6 @@ int fwts_uefi_get_variable_names(fwts_list *list);
>>>>    void fwts_uefi_print_status_info(fwts_framework *fw, const uint64_t
>>>> status);
>>>>    char *fwts_uefi_attribute_info(uint32_t attr);
>>>>
>>>> +bool fwts_uefi_efivars_iface_exist(void);
>>>> +
>>>>    #endif
>>>> diff --git a/src/lib/src/fwts_uefi.c b/src/lib/src/fwts_uefi.c
>>>> index f8678ab..55308ba 100644
>>>> --- a/src/lib/src/fwts_uefi.c
>>>> +++ b/src/lib/src/fwts_uefi.c
>>>> @@ -513,3 +513,15 @@ char *fwts_uefi_attribute_info(uint32_t attr)
>>>>
>>>>        return str;
>>>>    }
>>>> +
>>>> +/*
>>>> + *  fwts_uefi_efivars_fs_exist()
>>>> + *    check the efivar interface existfwts_uefi_get_interface(&path)
>>>> + */
>>>> +bool fwts_uefi_efivars_iface_exist(void)
>>>> +{
>>>> +    char *path;
>>>> +
>>>> +    return (fwts_uefi_get_interface(&path) == UEFI_IFACE_EFIVARS);
>>>> +
>>>> +}
>>>>
>>>
>>> Should we also be checking for the legacy UEFI_IFACE_SYSFS too? Or how
>>> about checking for no interface or failure:
>>>
>>> {
>>>      char *path;
>>>      int ret = fwts_uefi_get_interface(&path);
>>>
>>>      return (ret != UEFI_IFACE_NONE) && (ret != UEFI_IFACE_UNKNOWN);
>>> }
>>>
>>>
>>
>> The DB, and KEK variables are defined by the UEFI spec and used in UEFI
>> enviroment. I think it should be checked with the efivars interface
>> only, not in the legacy environment.
>
> The legacy UEFI_IFACE_SYSFS interface is the old kernel UEFI vars
> interface for older kernels, hence I believe it is required.
>
> Colin
>

Actually , I found that checking the secure boot variables db and kek 
via the vars interface will fail.
using hexdump and cat for these variables also failed,
u at u-HP-Pavilion-m4-Notebook-PC:/sys/firmware$ sudo hexdump 
efi/vars/db-d719b2cb-3d3a-4596-a3bc-dad00e67656f/data hexdump: 
efi/vars/db-d719b2cb-3d3a-4596-a3bc-dad00e67656f/data: Input/output error
,but efivars works fine. That's why I add the patches to specify using 
efivars interface for running the securebootcert test to avoid the 
unintentional fail from using vars interface.

Ivan