From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- Documentation/userspace-api/media/index.rst | 67 +++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 Documentation/userspace-api/media/index.rst (limited to 'Documentation/userspace-api/media/index.rst') diff --git a/Documentation/userspace-api/media/index.rst b/Documentation/userspace-api/media/index.rst new file mode 100644 index 000000000..337ef6c7c --- /dev/null +++ b/Documentation/userspace-api/media/index.rst @@ -0,0 +1,67 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. include:: + +######################################## +Linux Media Infrastructure userspace API +######################################## + +This section contains the driver development information and Kernel APIs +used by media devices. + +Please see: + +Documentation/admin-guide/media/index.rst + + - for usage information about media subsystem and supported drivers; + +Documentation/driver-api/media/index.rst + + - for driver development information and Kernel APIs used by + media devices; + + +.. toctree:: + :caption: Table of Contents + :maxdepth: 1 + + intro + v4l/v4l2 + dvb/dvbapi + rc/remote_controllers + mediactl/media-controller + cec/cec-api + gen-errors + + glossary + + fdl-appendix + + drivers/index + +**Copyright** |copy| 2009-2020 : LinuxTV Developers + +:: + + Permission is granted to copy, distribute and/or modify this document + under the terms of the GNU Free Documentation License, Version 1.1 or + any later version published by the Free Software Foundation, with no + Invariant Sections. A copy of the license is included in the chapter + entitled "GNU Free Documentation License". + +Please notice that some documents inside the media userspace API, +when explicitly mentioned on its source code, are dual-licensed +with GNU Free Documentation License Version 1.1 and with the +GNU General Public License:: + + This documentation is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by the Free + Software Foundation; either version 2 of the License, or (at your option) any + later version. + + This program is distributed in the hope that it will be useful, but WITHOUT + ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + more details. + + For more details see the file COPYING in the source distribution of Linux. -- cgit v1.3.1