linux-kernel - [PATCH 0/1] coresight: fix issue with insufficient claim tags

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20251021234520.3355-1-mike.leach@linaro.org>
Date: Wed, 22 Oct 2025 00:45:19 +0100
From: Mike Leach <mike.leach@...aro.org>
To: coresight@...ts.linaro.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org
Cc: suzuki.poulose@....com,
	leo.yan@....com,
	james.clark@...aro.org,
	Mike Leach <mike.leach@...aro.org>
Subject: [PATCH 0/1] coresight: fix issue with insufficient claim tags

All CoreSight compliant components have an implementation defined number
of 0 to 8 claim tag bits in the claim tag registers.

These are used to claim the CoreSight resources by system agents.

ARM recommends implementions have 4 claim tag registers.

The CoreSight drivers implement a 2 claim tag bit protocol to allow
self hosted and external debug agents to manage access to the hardware.

However, if there are less than 2 claim tags available the protocol
incorrectly returns an error on device claim, as no checks are made.

If insufficient claim tags are present in a component then the protocol
must return success on claim / disclaim to allow components to be used
normally.

Changes read the CLAIMSET bits to establish the number of available tags,
and adjust the claim returns accordingly.

Applies to coresignt/next

Mike Leach (1):
  coresight: fix issue where coresight component has no claimtags

 drivers/hwtracing/coresight/coresight-core.c | 26 ++++++++++++++++++++
 drivers/hwtracing/coresight/coresight-priv.h |  8 ++++++
 2 files changed, 34 insertions(+)

-- 
2.32.0