From 506ada89629ec7059b96ecfb0dc7d33ece0103ca Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 17:05:56 -0700 Subject: bpf: mark a NULL kfunc argument precise check_kfunc_arg() allows bpf_register_is_null() for nullable arguments w/o marking the underlying scalar register precise. Hence a checkpoint created on such a path would prune against arbitrary scalar value. Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)") Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov --- Documentation/userspace-api/media/intro.rst | 46 +++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 Documentation/userspace-api/media/intro.rst (limited to 'Documentation/userspace-api/media/intro.rst') diff --git a/Documentation/userspace-api/media/intro.rst b/Documentation/userspace-api/media/intro.rst new file mode 100644 index 000000000..4a6bd665b --- /dev/null +++ b/Documentation/userspace-api/media/intro.rst @@ -0,0 +1,46 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============ +Introduction +============ + +This document covers the Linux Kernel to Userspace API's used by video +and radio streaming devices, including video cameras, analog and digital +TV receiver cards, AM/FM receiver cards, Software Defined Radio (SDR), +streaming capture and output devices, codec devices and remote controllers. + +A typical media device hardware is shown at :ref:`typical_media_device`. + +.. _typical_media_device: + +.. kernel-figure:: typical_media_device.svg + :alt: typical_media_device.svg + :align: center + + Typical Media Device + +The media infrastructure API was designed to control such devices. It is +divided into five parts. + +1. The :ref:`first part ` covers radio, video capture and output, + cameras, analog TV devices and codecs. + +2. The :ref:`second part ` covers the API used for digital TV and + Internet reception via one of the several digital tv standards. While it is + called as DVB API, in fact it covers several different video standards + including DVB-T/T2, DVB-S/S2, DVB-C, ATSC, ISDB-T, ISDB-S, DTMB, etc. The + complete list of supported standards can be found at + :c:type:`fe_delivery_system`. + +3. The :ref:`third part ` covers the Remote Controller API. + +4. The :ref:`fourth part ` covers the Media Controller API. + +5. The :ref:`fifth part ` covers the CEC (Consumer Electronics Control) API. + +It should also be noted that a media device may also have audio components, like +mixers, PCM capture, PCM playback, etc, which are controlled via ALSA API. For +additional information and for the latest development code, see: +`https://linuxtv.org `__. For discussing improvements, +reporting troubles, sending new drivers, etc, please mail to: `Linux Media +Mailing List (LMML) `__. -- cgit v1.3.1