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>

1 files changed, 31 insertions, 0 deletions

diff --git a/fs/hfsplus/Kconfig b/fs/hfsplus/Kconfig
new file mode 100644
index 000000000..ca8401cb6
--- /dev/null
+++ b/fs/hfsplus/Kconfig
@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config HFSPLUS_FS
+	tristate "Apple Extended HFS file system support"
+	depends on BLOCK
+	select BUFFER_HEAD
+	select NLS
+	select NLS_UTF8
+	select LEGACY_DIRECT_IO
+	help
+	  If you say Y here, you will be able to mount extended format
+	  Macintosh-formatted hard drive partitions with full read-write access.
+
+	  This file system is often called HFS+ and was introduced with
+	  MacOS 8. It includes all Mac specific filesystem data such as
+	  data forks and creator codes, but it also has several UNIX
+	  style features such as file ownership and permissions.
+
+config HFSPLUS_KUNIT_TEST
+	tristate "KUnit tests for HFS+ filesystem" if !KUNIT_ALL_TESTS
+	depends on HFSPLUS_FS && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This builds KUnit tests for the HFS+ filesystem.
+
+	  KUnit tests run during boot and output the results to the debug
+	  log in TAP format (https://testanything.org/). Only useful for
+	  kernel devs running KUnit test harness and are not for inclusion
+	  into a production build.
+
+	  For more information on KUnit and unit tests in general please
+	  refer to the KUnit documentation in Documentation/dev-tools/kunit/.