From 5f486958bfae4e2059a26b947661a60efedd092d Mon Sep 17 00:00:00 2001 From: Kuppuswamy Sathyanarayanan Date: Tue, 10 Feb 2026 16:17:10 -0800 Subject: [PATCH] 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: Fang Peter Signed-off-by: Kuppuswamy Sathyanarayanan Link: https://patch.msgid.link/20260211001712.1531955-2-sathyanarayanan.kuppuswamy@linux.intel.com Signed-off-by: Dan Williams --- Documentation/ABI/testing/configfs-tsm-report | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/Documentation/ABI/testing/configfs-tsm-report b/Documentation/ABI/testing/configfs-tsm-report index 534408bc1408f..ca3352cfd2f1f 100644 --- a/Documentation/ABI/testing/configfs-tsm-report +++ b/Documentation/ABI/testing/configfs-tsm-report @@ -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 -- 2.47.3