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, 27 insertions, 0 deletions

diff --git a/fs/minix/Kconfig b/fs/minix/Kconfig
new file mode 100644
index 000000000..90ddfad2a
--- /dev/null
+++ b/fs/minix/Kconfig
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config MINIX_FS
+	tristate "Minix file system support"
+	depends on BLOCK
+	select BUFFER_HEAD
+	help
+	  Minix is a simple operating system used in many classes about OS's.
+	  The minix file system (method to organize files on a hard disk
+	  partition or a floppy disk) was the original file system for Linux,
+	  but has been superseded by the second extended file system ext2fs.
+	  You don't want to use the minix file system on your hard disk
+	  because of certain built-in restrictions, but it is sometimes found
+	  on older Linux floppy disks.  This option will enlarge your kernel
+	  by about 28 KB. If unsure, say N.
+
+	  To compile this file system support as a module, choose M here: the
+	  module will be called minix.  Note that the file system of your root
+	  partition (the one containing the directory /) cannot be compiled as
+	  a module.
+
+config MINIX_FS_NATIVE_ENDIAN
+	def_bool MINIX_FS
+	depends on MICROBLAZE || MIPS || S390 || SUPERH || SPARC || XTENSA || (M68K && !MMU)
+
+config MINIX_FS_BIG_ENDIAN_16BIT_INDEXED
+	def_bool MINIX_FS
+	depends on M68K && MMU