linux-kernel - [PATCH v8 0/3] drm/bridge: add kunit tests for devm_drm_bridge

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 for Android: free password hash cracker in your pocket

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

Message-Id: <20250516-drm-bridge-alloc-doc-test-v8-0-7e356fd58ba5@bootlin.com>
Date: Fri, 16 May 2025 18:48:36 +0200
From: Luca Ceresoli <luca.ceresoli@...tlin.com>
To: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>, 
 David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, 
 Andrzej Hajda <andrzej.hajda@...el.com>, 
 Neil Armstrong <neil.armstrong@...aro.org>, Robert Foss <rfoss@...nel.org>, 
 Laurent Pinchart <Laurent.pinchart@...asonboard.com>, 
 Jonas Karlman <jonas@...boo.se>, Jernej Skrabec <jernej.skrabec@...il.com>
Cc: Anusha Srivatsa <asrivats@...hat.com>, 
 Paul Kocialkowski <paulk@...-base.io>, Dmitry Baryshkov <lumag@...nel.org>, 
 Hervé Codina <herve.codina@...tlin.com>, 
 Hui Pu <Hui.Pu@...ealthcare.com>, 
 Thomas Petazzoni <thomas.petazzoni@...tlin.com>, 
 dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org, 
 Luca Ceresoli <luca.ceresoli@...tlin.com>
Subject: [PATCH v8 0/3] drm/bridge: add kunit tests for
 devm_drm_bridge_alloc()

This small series adds a few kunit tests for the new DRM bridge allocation
flow, based on the recently introduced devm_drm_bridge_alloc() [0].

It is part of the work towards removal of bridges from a still existing DRM
pipeline without use-after-free.

The steps in the grand plan [1] are:

 1. ➜ add refcounting to DRM bridges (struct drm_bridge)
 2. handle gracefully atomic updates during bridge removal
 3. avoid DSI host drivers to have dangling pointers to DSI devices
 4. finish the hotplug bridge work, removing the "always-disconnected"
    connector, moving code to the core and potentially removing the
    hotplug-bridge itself (this needs to be clarified as points 1-3 are
    developed)

This series is part of step 1 of the grand plan.

Current tasks in step 1 of the grand plan:

 A. ✔ add new alloc API and refcounting -> (now in drm-misc-next)
 B. … convert all bridge drivers to new API (in progress)
 C. ➜ kunit tests (this series)
 D. after (B), add get/put to drm_bridge_add/remove() + attach/detech()
 E. after (B), convert accessors; this is a large work and can be done
    in chunks
 F. debugfs improvements

[0] https://gitlab.freedesktop.org/drm/misc/kernel/-/commit/0cc6aadd7fc1e629b715ea3d1ba537ef2da95eec
[1] https://lore.kernel.org/lkml/20250206-hotplug-drm-bridge-v6-0-9d6f2c9c3058@bootlin.com/t/#u

Signed-off-by: Luca Ceresoli <luca.ceresoli@...tlin.com>
---
Changes in v8:
- Remove documentation patch
- Add patch to convert existing kunit tests to use devm_drm_bridge_alloc()
- Add tests for bridge deallocation (based on adding a .destroy callback)
- Link to v7: https://lore.kernel.org/r/20250409-drm-bridge-alloc-doc-test-v7-0-a3ca4b97597f@bootlin.com

---
Luca Ceresoli (3):
      drm/tests: bridge: convert to devm_drm_bridge_alloc() API
      dmr/bridge: add a .destroy func
      drm/tests: bridge: add KUnit tests for devm_drm_bridge_alloc()

 drivers/gpu/drm/drm_bridge.c            |   2 +
 drivers/gpu/drm/tests/drm_bridge_test.c | 179 +++++++++++++++++++++++++-------
 include/drm/drm_bridge.h                |  10 ++
 3 files changed, 151 insertions(+), 40 deletions(-)
---
base-commit: aec8a40228acb385d60feec59b54573d307e60f3
change-id: 20250408-drm-bridge-alloc-doc-test-267df0def880

Best regards,
-- 
Luca Ceresoli <luca.ceresoli@...tlin.com>