[PATCH] efi_loader: Do not show error message if TPM is not present

[Michal Simek]

On 11/29/21 14:30, Ilias Apalodimas wrote:
> Hi Michal,
> 
> On Mon, 29 Nov 2021 at 15:06, Michal Simek <michal.simek at xilinx.com> wrote:
>>
>> For systems which have TPM support enabled but actual device is missing
>> there is no reason to show a message that measurement failed.
>> That's why properly check error code which is returned.
>>
>> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
>> ---
>>
>>   lib/efi_loader/efi_image_loader.c | 5 +++--
>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c
>> index eb95580538cc..c6a254dc25dd 100644
>> --- a/lib/efi_loader/efi_image_loader.c
>> +++ b/lib/efi_loader/efi_image_loader.c
>> @@ -934,8 +934,9 @@ efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle,
>>
>>   #if CONFIG_IS_ENABLED(EFI_TCG2_PROTOCOL)
>>          /* Measure an PE/COFF image */
>> -       if (tcg2_measure_pe_image(efi, efi_size, handle,
>> -                                 loaded_image_info))
>> +       ret = tcg2_measure_pe_image(efi, efi_size, handle,
>> +                                   loaded_image_info);
>> +       if (ret && ret != EFI_NOT_FOUND)
>>                  log_err("PE image measurement failed\n");
>>   #endif
> 
> Indeed that's needed.  Looking at it again though maybe it's better to
> add an identical check in tcg2_measure_pe_image() and return
> EFI_SUCCESS if platform_get_tpm2_device() returned EFI_NOT_FOUND.  The
> reason is that other parts of the code return EFI_NOT_FOUND in that
> function (e.g efi_search_protocol).  So we need to make sure we report
> the error in that case.

just like this?

diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index 8c1f22e3377b..db6e7488b7fb 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -887,8 +887,10 @@ efi_status_t tcg2_measure_pe_image(void *efi, u64 
efi_size,
         struct efi_handler *handler;

         ret = platform_get_tpm2_device(&dev);
-       if (ret != EFI_SUCCESS)
+       if (ret != EFI_SUCCESS) {
+               ret = EFI_SUCCESS;
                 return ret;
+       }

         switch (handle->image_type) {
         case IMAGE_SUBSYSTEM_EFI_APPLICATION:


M