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/arch/nios2/features.rst | 3 +++ Documentation/arch/nios2/index.rst | 12 ++++++++++++ Documentation/arch/nios2/nios2.rst | 24 ++++++++++++++++++++++++ 3 files changed, 39 insertions(+) create mode 100644 Documentation/arch/nios2/features.rst create mode 100644 Documentation/arch/nios2/index.rst create mode 100644 Documentation/arch/nios2/nios2.rst (limited to 'Documentation/arch/nios2') diff --git a/Documentation/arch/nios2/features.rst b/Documentation/arch/nios2/features.rst new file mode 100644 index 000000000..89913810c --- /dev/null +++ b/Documentation/arch/nios2/features.rst @@ -0,0 +1,3 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. kernel-feat:: features nios2 diff --git a/Documentation/arch/nios2/index.rst b/Documentation/arch/nios2/index.rst new file mode 100644 index 000000000..4468fe1a1 --- /dev/null +++ b/Documentation/arch/nios2/index.rst @@ -0,0 +1,12 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================== +Nios II Specific Documentation +============================== + +.. toctree:: + :maxdepth: 2 + :numbered: + + nios2 + features diff --git a/Documentation/arch/nios2/nios2.rst b/Documentation/arch/nios2/nios2.rst new file mode 100644 index 000000000..43da3f7ce --- /dev/null +++ b/Documentation/arch/nios2/nios2.rst @@ -0,0 +1,24 @@ +================================= +Linux on the Nios II architecture +================================= + +This is a port of Linux to Nios II (nios2) processor. + +In order to compile for Nios II, you need a version of GCC with support for the generic +system call ABI. Please see this link for more information on how compiling and booting +software for the Nios II platform: +http://www.rocketboards.org/foswiki/Documentation/NiosIILinuxUserManual + +For reference, please see the following link: +http://www.altera.com/literature/lit-nio2.jsp + +What is Nios II? +================ +Nios II is a 32-bit embedded-processor architecture designed specifically for the +Altera family of FPGAs. In order to support Linux, Nios II needs to be configured +with MMU and hardware multiplier enabled. + +Nios II ABI +=========== +Please refer to chapter "Application Binary Interface" in Nios II Processor Reference +Handbook. -- cgit v1.3.1