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/netlabel/introduction.rst | 52 +++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 Documentation/netlabel/introduction.rst (limited to 'Documentation/netlabel/introduction.rst') diff --git a/Documentation/netlabel/introduction.rst b/Documentation/netlabel/introduction.rst new file mode 100644 index 000000000..9333bbb0a --- /dev/null +++ b/Documentation/netlabel/introduction.rst @@ -0,0 +1,52 @@ +===================== +NetLabel Introduction +===================== + +Paul Moore, paul.moore@hp.com + +August 2, 2006 + +Overview +======== + +NetLabel is a mechanism which can be used by kernel security modules to attach +security attributes to outgoing network packets generated from user space +applications and read security attributes from incoming network packets. It +is composed of three main components, the protocol engines, the communication +layer, and the kernel security module API. + +Protocol Engines +================ + +The protocol engines are responsible for both applying and retrieving the +network packet's security attributes. If any translation between the network +security attributes and those on the host are required then the protocol +engine will handle those tasks as well. Other kernel subsystems should +refrain from calling the protocol engines directly, instead they should use +the NetLabel kernel security module API described below. + +Detailed information about each NetLabel protocol engine can be found in this +directory. + +Communication Layer +=================== + +The communication layer exists to allow NetLabel configuration and monitoring +from user space. The NetLabel communication layer uses a message based +protocol built on top of the Generic NETLINK transport mechanism. The exact +formatting of these NetLabel messages as well as the Generic NETLINK family +names can be found in the 'net/netlabel/' directory as comments in the +header files as well as in 'include/net/netlabel.h'. + +Security Module API +=================== + +The purpose of the NetLabel security module API is to provide a protocol +independent interface to the underlying NetLabel protocol engines. In addition +to protocol independence, the security module API is designed to be completely +LSM independent which should allow multiple LSMs to leverage the same code +base. + +Detailed information about the NetLabel security module API can be found in the +'include/net/netlabel.h' header file as well as the 'lsm_interface.txt' file +found in this directory. -- cgit v1.3.1