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, 100 insertions, 0 deletions

diff --git a/security/selinux/Kconfig b/security/selinux/Kconfig
new file mode 100644
index 000000000..5588c4d57
--- /dev/null
+++ b/security/selinux/Kconfig
@@ -0,0 +1,100 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config SECURITY_SELINUX
+	bool "SELinux Support"
+	depends on SECURITY_NETWORK && AUDIT && NET && INET
+	select NETWORK_SECMARK
+	default n
+	help
+	  This selects Security-Enhanced Linux (SELinux).
+	  You will also need a policy configuration and a labeled filesystem.
+	  If you are unsure how to answer this question, answer N.
+
+config SECURITY_SELINUX_BOOTPARAM
+	bool "SELinux boot parameter"
+	depends on SECURITY_SELINUX
+	default n
+	help
+	  This option adds a kernel parameter 'selinux', which allows SELinux
+	  to be disabled at boot.  If this option is selected, SELinux
+	  functionality can be disabled with selinux=0 on the kernel
+	  command line.  The purpose of this option is to allow a single
+	  kernel image to be distributed with SELinux built in, but not
+	  necessarily enabled.
+
+	  If you are unsure how to answer this question, answer N.
+
+config SECURITY_SELINUX_DEVELOP
+	bool "SELinux Development Support"
+	depends on SECURITY_SELINUX
+	default y
+	help
+	  This enables the development support option of SELinux,
+	  which is useful for experimenting with SELinux and developing
+	  policies.  If unsure, say Y.  With this option enabled, the
+	  kernel will start in permissive mode (log everything, deny nothing)
+	  unless you specify enforcing=1 on the kernel command line.  You
+	  can interactively toggle the kernel between enforcing mode and
+	  permissive mode (if permitted by the policy) via
+	  /sys/fs/selinux/enforce.
+
+config SECURITY_SELINUX_AVC_STATS
+	bool "SELinux AVC Statistics"
+	depends on SECURITY_SELINUX
+	default y
+	help
+	  This option collects access vector cache statistics to
+	  /sys/fs/selinux/avc/cache_stats, which may be monitored via
+	  tools such as avcstat.
+
+config SECURITY_SELINUX_SIDTAB_HASH_BITS
+	int "SELinux sidtab hashtable size"
+	depends on SECURITY_SELINUX
+	range 8 13
+	default 9
+	help
+	  This option sets the number of buckets used in the sidtab hashtable
+	  to 2^SECURITY_SELINUX_SIDTAB_HASH_BITS buckets. The number of hash
+	  collisions may be viewed at /sys/fs/selinux/ss/sidtab_hash_stats. If
+	  chain lengths are high (e.g. > 20) then selecting a higher value here
+	  will ensure that lookups times are short and stable.
+
+config SECURITY_SELINUX_SID2STR_CACHE_SIZE
+	int "SELinux SID to context string translation cache size"
+	depends on SECURITY_SELINUX
+	default 256
+	help
+	  This option defines the size of the internal SID -> context string
+	  cache, which improves the performance of context to string
+	  conversion.  Setting this option to 0 disables the cache completely.
+
+	  If unsure, keep the default value.
+
+config SECURITY_SELINUX_AVC_HASH_BITS
+	int "SELinux avc hashtable size"
+	depends on SECURITY_SELINUX
+	range 9 14
+	default 9
+	help
+	  This option sets the number of buckets used in the AVC hash table
+	  to 2^SECURITY_SELINUX_AVC_HASH_BITS. A higher value helps maintain
+	  shorter chain lengths especially when expanding AVC nodes via
+	  /sys/fs/selinux/avc/cache_threshold.
+
+config SECURITY_SELINUX_DEBUG
+	bool "SELinux kernel debugging support"
+	depends on SECURITY_SELINUX
+	default n
+	help
+	  This enables debugging code designed to help SELinux kernel
+	  developers, unless you know what this does in the kernel code you
+	  should leave this disabled.
+
+	  To fine control the messages to be printed enable
+	  CONFIG_DYNAMIC_DEBUG and see
+	  Documentation/admin-guide/dynamic-debug-howto.rst for additional
+	  information.
+
+	  Example usage:
+
+		echo -n 'file "security/selinux/*" +p' > \
+			/proc/dynamic_debug/control