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, 41 insertions, 0 deletions

diff --git a/fs/isofs/Kconfig b/fs/isofs/Kconfig
new file mode 100644
index 000000000..51434f2a4
--- /dev/null
+++ b/fs/isofs/Kconfig
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config ISO9660_FS
+	tristate "ISO 9660 CDROM file system support"
+	select BUFFER_HEAD
+	help
+	  This is the standard file system used on CD-ROMs.  It was previously
+	  known as "High Sierra File System" and is called "hsfs" on other
+	  Unix systems.  The so-called Rock-Ridge extensions which allow for
+	  long Unix filenames and symbolic links are also supported by this
+	  driver.  If you have a CD-ROM drive and want to do more with it than
+	  just listen to audio CDs and watch its LEDs, say Y (and read
+	  <file:Documentation/filesystems/isofs.rst> and the CD-ROM-HOWTO,
+	  available from <http://www.tldp.org/docs.html#howto>), thereby
+	  enlarging your kernel by about 27 KB; otherwise say N.
+
+	  To compile this file system support as a module, choose M here: the
+	  module will be called isofs.
+
+config JOLIET
+	bool "Microsoft Joliet CDROM extensions"
+	depends on ISO9660_FS
+	select NLS
+	help
+	  Joliet is a Microsoft extension for the ISO 9660 CD-ROM file system
+	  which allows for long filenames in unicode format (unicode is the
+	  new 16 bit character code, successor to ASCII, which encodes the
+	  characters of almost all languages of the world; see
+	  <http://www.unicode.org/> for more information).  Say Y here if you
+	  want to be able to read Joliet CD-ROMs under Linux.
+
+config ZISOFS
+	bool "Transparent decompression extension"
+	depends on ISO9660_FS
+	select ZLIB_INFLATE
+	help
+	  This is a Linux-specific extension to RockRidge which lets you store
+	  data in compressed form on a CD-ROM and have it transparently
+	  decompressed when the CD-ROM is accessed.  See
+	  <http://www.kernel.org/pub/linux/utils/fs/zisofs/> for the tools
+	  necessary to create such a filesystem.  Say Y here if you want to be
+	  able to read such compressed CD-ROMs.