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| author | Steven Rostedt <rostedt@goodmis.org> | 2026-09-02 09:55:01 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2026-09-02 11:08:21 -0400 |
| commit | 4617721c502b2ddaa4e324e86da4997edf738fa5 (patch) | |
| tree | 350aa83b47da0b574a814795392b20b0bed83cbc /Documentation/arch/nios2 | |
| download | linux-stable-4617721c502b2ddaa4e324e86da4997edf738fa5.tar.gz linux-stable-4617721c502b2ddaa4e324e86da4997edf738fa5.zip | |
ftrace: Synchronize the initialization of ftrace_opsgrafted
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 <rostedt@goodmis.org>
Diffstat (limited to 'Documentation/arch/nios2')
| -rw-r--r-- | Documentation/arch/nios2/features.rst | 3 | ||||
| -rw-r--r-- | Documentation/arch/nios2/index.rst | 12 | ||||
| -rw-r--r-- | Documentation/arch/nios2/nios2.rst | 24 |
3 files changed, 39 insertions, 0 deletions
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. |