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, 85 insertions, 0 deletions

diff --git a/security/tomoyo/Kconfig b/security/tomoyo/Kconfig
new file mode 100644
index 000000000..1e0dd1a6d
--- /dev/null
+++ b/security/tomoyo/Kconfig
@@ -0,0 +1,85 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config SECURITY_TOMOYO
+	bool "TOMOYO Linux Support"
+	depends on SECURITY
+	depends on NET
+	select SECURITYFS
+	select SECURITY_PATH
+	select SECURITY_NETWORK
+	default n
+	help
+	  This selects TOMOYO Linux, pathname-based access control.
+	  Required userspace tools and further information may be
+	  found at <https://tomoyo.sourceforge.net/>.
+	  If you are unsure how to answer this question, answer N.
+
+config SECURITY_TOMOYO_MAX_ACCEPT_ENTRY
+	int "Default maximal count for learning mode"
+	default 2048
+	range 0 2147483647
+	depends on SECURITY_TOMOYO
+	help
+	  This is the default value for maximal ACL entries
+	  that are automatically appended into policy at "learning mode".
+	  Some programs access thousands of objects, so running
+	  such programs in "learning mode" dulls the system response
+	  and consumes much memory.
+	  This is the safeguard for such programs.
+
+config SECURITY_TOMOYO_MAX_AUDIT_LOG
+	int "Default maximal count for audit log"
+	default 1024
+	range 0 2147483647
+	depends on SECURITY_TOMOYO
+	help
+	  This is the default value for maximal entries for
+	  audit logs that the kernel can hold on memory.
+	  You can read the log via /sys/kernel/security/tomoyo/audit.
+	  If you don't need audit logs, you may set this value to 0.
+
+config SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
+	bool "Activate without calling userspace policy loader."
+	default n
+	depends on SECURITY_TOMOYO
+	help
+	  Say Y here if you want to activate access control as soon as built-in
+	  policy was loaded. This option will be useful for systems where
+	  operations which can lead to the hijacking of the boot sequence are
+	  needed before loading the policy. For example, you can activate
+	  immediately after loading the fixed part of policy which will allow
+	  only operations needed for mounting a partition which contains the
+	  variant part of policy and verifying (e.g. running GPG check) and
+	  loading the variant part of policy. Since you can start using
+	  enforcing mode from the beginning, you can reduce the possibility of
+	  hijacking the boot sequence.
+
+config SECURITY_TOMOYO_POLICY_LOADER
+	string "Location of userspace policy loader"
+	default "/sbin/tomoyo-init"
+	depends on SECURITY_TOMOYO
+	depends on !SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
+	help
+	  This is the default pathname of policy loader which is called before
+	  activation. You can override this setting via TOMOYO_loader= kernel
+	  command line option.
+
+config SECURITY_TOMOYO_ACTIVATION_TRIGGER
+	string "Trigger for calling userspace policy loader"
+	default "/sbin/init"
+	depends on SECURITY_TOMOYO
+	depends on !SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
+	help
+	  This is the default pathname of activation trigger.
+	  You can override this setting via TOMOYO_trigger= kernel command line
+	  option. For example, if you pass init=/bin/systemd option, you may
+	  want to also pass TOMOYO_trigger=/bin/systemd option.
+
+config SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING
+	bool "Use insecure built-in settings for fuzzing tests."
+	default n
+	depends on SECURITY_TOMOYO
+	select SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
+	help
+	  Enabling this option forces minimal built-in policy and disables
+	  domain/program checks for run-time policy modifications. Please enable
+	  this option only if this kernel is built for doing fuzzing tests.