Re: [PATCH v6 05/14] x86: Secure Launch main header file

[ross . philipson]

On 5/12/23 9:10 AM, Ross Philipson wrote:
> On 5/12/23 07:00, Matthew Garrett wrote:
> > On Thu, May 04, 2023 at 02:50:14PM +0000, Ross Philipson wrote:
> >
> > > +static inline int tpm12_log_event(void *evtlog_base, u32 evtlog_size,
> > > +                  u32 event_size, void *event)
> > > +{
> > > +    struct tpm12_event_log_header *evtlog =
> > > +        (struct tpm12_event_log_header *)evtlog_base;
> > > +
> > > +    if (memcmp(evtlog->signature, TPM12_EVTLOG_SIGNATURE,
> > > +           sizeof(TPM12_EVTLOG_SIGNATURE)))
> > > +        return -EINVAL;
> > > +
> > > +    if (evtlog->container_size > evtlog_size)
> > > +        return -EINVAL;
> > > +
> > > +    if (evtlog->next_event_offset + event_size > 
> > > evtlog->container_size)
> > > +        return -E2BIG;
> > > +
> > > +    memcpy(evtlog_base + evtlog->next_event_offset, event, event_size);
> > > +    evtlog->next_event_offset += event_size;
> > > +
> > > +    return 0;
> > > +}
> > > +
> > > +static inline int tpm20_log_event(struct 
> > > txt_heap_event_log_pointer2_1_element *elem,
> > > +                  void *evtlog_base, u32 evtlog_size,
> > > +                  u32 event_size, void *event)
> > > +{
> > > +    struct tcg_pcr_event *header =
> > > +        (struct tcg_pcr_event *)evtlog_base;
> > > +
> > > +    /* Has to be at least big enough for the signature */
> > > +    if (header->event_size < sizeof(TCG_SPECID_SIG))
> > > +        return -EINVAL;
> > > +
> > > +    if (memcmp((u8 *)header + sizeof(struct tcg_pcr_event),
> > > +           TCG_SPECID_SIG, sizeof(TCG_SPECID_SIG)))
> > > +        return -EINVAL;
> > > +
> > > +    if (elem->allocated_event_container_size > evtlog_size)
> > > +        return -EINVAL;
> > > +
> > > +    if (elem->next_record_offset + event_size >
> > > +        elem->allocated_event_container_size)
> > > +        return -E2BIG;
> > > +
> > > +    memcpy(evtlog_base + elem->next_record_offset, event, event_size);
> > > +    elem->next_record_offset += event_size;
> > > +
> > > +    return 0;
> > > +}
> > > +
> >
> > These seem like they'd potentially be useful outside the context of SL,
> > maybe put them in a more generic location? Very much a nice to have, not
> > a blocker from my side.
>
> Yea we can look into finding a nice home somewhere in the TPM event log 
> code for these.

After looking at it, it seems we would have to drag a whole bunch of TXT 
related structures into the TPM event log code. I don't think this is 
really worth it for what these functions do.

Thanks
Ross

> > > +/*
> > > + * External functions avalailable in mainline kernel.
> >
> > Nit: "available"
>
> Ack
>
> Thanks
>
> >