Commit 5f486958 authored by Kuppuswamy Sathyanarayanan's avatar Kuppuswamy Sathyanarayanan Committed by Dan Williams
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configfs-tsm-report: Document size limits for outblob attributes 



The configfs-tsm-report interface can fail with -EFBIG when the
attestation report generated by a TSM provider exceeds internal
maximums (TSM_REPORT_OUTBLOB_MAX). However, this error condition and
its handling are not currently documented in the ABI.

Userspace tools need to understand how to interpret various error
conditions when reading attestation reports.

Document that reads fail with -EFBIG when reports exceed size limits,
with guidance on how to resolve them.

Reviewed-by: default avatarFang Peter <peter.fang@intel.com>
Signed-off-by: default avatarKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/20260211001712.1531955-2-sathyanarayanan.kuppuswamy@linux.intel.com


Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 18f7fcd5

Documentation/ABI/testing/configfs-tsm-report

+12 −0
Original line number Diff line number Diff line
@@ -17,6 +17,12 @@ Description: 
		where the implementation is conveyed via the @provider

		attribute.



		This interface fails reads and sets errno to EFBIG when the

		report generated by @provider exceeds the configfs-tsm-report

		internal maximums. Contact the platform provider for the

		compatible security module, driver, and attestation library

		combination.



What:		/sys/kernel/config/tsm/report/$name/auxblob

Date:		October, 2023

KernelVersion:	v6.7
@@ -31,6 +37,9 @@ Description: 
		Standardization v2.03 Section 4.1.8.1 MSG_REPORT_REQ.

		https://www.amd.com/content/dam/amd/en/documents/epyc-technical-docs/specifications/56421.pdf



		See "EFBIG" comment in the @outblob description for potential

		error conditions.



What:		/sys/kernel/config/tsm/report/$name/manifestblob

Date:		January, 2024

KernelVersion:	v6.10
@@ -43,6 +52,9 @@ Description: 
		See 'service_provider' for information on the format of the

		manifest blob.



		See "EFBIG" comment in the @outblob description for potential

		error conditions.



What:		/sys/kernel/config/tsm/report/$name/provider

Date:		September, 2023

KernelVersion:	v6.7