[PATCH v2 3/3] tpm: allocate tpm event log if missing

[Ludwig Nussel]

On 6/16/26 10:40, Ilias Apalodimas wrote:
> On Tue, 16 Jun 2026 at 11:12, Ludwig Nussel <ludwig.nussel at siemens.com> wrote:
>>
>> On 6/11/26 11:57, Ilias Apalodimas wrote:
>>> On Wed, 10 Jun 2026 at 13:52, Ludwig Nussel <ludwig.nussel at siemens.com> wrote:
>>>> [...]
>>>>    /**
>>>> diff --git a/include/tpm_tcg2.h b/include/tpm_tcg2.h
>>>> index eb6afe49e77..db3f6f486e9 100644
>>>> --- a/include/tpm_tcg2.h
>>>> +++ b/include/tpm_tcg2.h
>>>> @@ -162,12 +162,14 @@ struct tcg_efi_spec_id_event {
>>>>     * @log_position:      Current entry position
>>>>     * @log_size:          Log space available
>>>>     * @found:             Boolean indicating if an existing log was discovered
>>>> + * @allocated:         Boolean indicating that the log was allocated by u-boot
>>>>     */
>>>>    struct tcg2_event_log {
>>>>           u8 *log;
>>>>           u32 log_position;
>>>>           u32 log_size;
>>>>           bool found;
>>>> +       bool allocated;
>>>>    };
>>>
>>> I think it makes more sense to define an eventlog state with a u32 and
>>> replace the found boolean with it. e.g
>>>
>>> #define ELOG_FOUND BIT(0)
>>> #define ELOG_ALLOCATED BIT(1) etc
>>
>> Is there a specific reason why explicit low level bit operations would
>> be preferred? Since the structure is only used as internal data
>> structure of u-boot, what about declaring bits like this:
>>
>> +       bool found:1;
>> +       bool allocated:1;
>>
>> Looks like that style is also used within U-Boot.
> 
> With the patches I pointed you at there are a bunch of booleans before
> this as well, so I doubt declaring bitflelds will make the struct
> smaller in the end. Padding/alignment will probably give you the same
> size.
> 
> OTOH the patches introduce more states that are conceptually relevant
> to the eventlog.
> The updated struct looks like
> struct tcg2_event_log {
> void *log;
> u32 log_size;
> u32 log_position;
> void *final_buffer;
> u32 final_position;
> u32 last_event_size;
> bool get_event_called;
> bool ebs_called;
> bool truncated;
> bool found;
> bool allocated;
> };
> 
> The TCG2 code behaves different if GetEvent or ExitBootServices has
> been called as far as the EventLog is concerned. So I think it would
> make more sense to encode the last four booleans to a 'log_state' (or
> something along those lines) variable.

To clarify, you are asking me to change the code like this, right?

- !elog.found
+ !(elog.log_state & ELOG_FOUND)

- elog.found = true
+ elog.log_state |= ELOG_FOUND

- elog->found = false
+ elog->log_state &= ~ELOG_FOUND

If that's what's preventing the patches from getting in I will do it of 
course.

cu
Ludwig

-- 
Ludwig Nussel
Siemens AG
www.siemens.com