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

From: ross.philipson@oracle.com
To: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
	linux-integrity@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-crypto@vger.kernel.org, iommu@lists.linux-foundation.org,
	kexec@lists.infradead.org, linux-efi@vger.kernel.org,
	dpsmith@apertussolutions.com, tglx@linutronix.de,
	mingo@redhat.com, bp@alien8.de, hpa@zytor.com, ardb@kernel.org,
	James.Bottomley@hansenpartnership.com, luto@amacapital.net,
	nivedita@alum.mit.edu, kanth.ghatraju@oracle.com,
	trenchboot-devel@googlegroups.com
Subject: Re: [PATCH v6 05/14] x86: Secure Launch main header file
Date: Tue, 31 Oct 2023 17:37:47 -0400	[thread overview]
Message-ID: <b32913fd-3b86-cebf-8240-4e0bc05f883d@oracle.com> (raw)
In-Reply-To: <2f7689e0-b79a-c642-815f-a487c1b9e700@oracle.com>

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
> 
>>
> 

_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec