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, 75 insertions, 0 deletions

diff --git a/net/sctp/Kconfig b/net/sctp/Kconfig
new file mode 100644
index 000000000..fc989a379
--- /dev/null
+++ b/net/sctp/Kconfig
@@ -0,0 +1,75 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# SCTP configuration
+#
+
+menuconfig IP_SCTP
+	tristate "The SCTP Protocol"
+	depends on INET
+	select CRYPTO_LIB_SHA1
+	select CRYPTO_LIB_SHA256
+	select CRYPTO_LIB_UTILS
+	select NET_CRC32C
+	select NET_UDP_TUNNEL
+	help
+	  Stream Control Transmission Protocol
+
+	  From RFC 2960 <http://www.ietf.org/rfc/rfc2960.txt>.
+
+	  "SCTP is a reliable transport protocol operating on top of a
+	  connectionless packet network such as IP.  It offers the following
+	  services to its users:
+
+	  -- acknowledged error-free non-duplicated transfer of user data,
+	  -- data fragmentation to conform to discovered path MTU size,
+	  -- sequenced delivery of user messages within multiple streams,
+	  with an option for order-of-arrival delivery of individual user
+	  messages,
+	  -- optional bundling of multiple user messages into a single SCTP
+	  packet, and
+	  -- network-level fault tolerance through supporting of multi-
+	  homing at either or both ends of an association."
+
+	  To compile this protocol support as a module, choose M here: the
+	  module will be called sctp. Debug messages are handled by the
+	  kernel's dynamic debugging framework.
+
+	  If in doubt, say N.
+
+if IP_SCTP
+
+config SCTP_DBG_OBJCNT
+	bool "SCTP: Debug object counts"
+	depends on PROC_FS
+	help
+	  If you say Y, this will enable debugging support for counting the
+	  type of objects that are currently allocated.  This is useful for
+	  identifying memory leaks. This debug information can be viewed by
+	  'cat /proc/net/sctp/sctp_dbg_objcnt'
+
+	  If unsure, say N
+
+choice
+	prompt "Default SCTP cookie authentication method"
+	default SCTP_DEFAULT_COOKIE_HMAC_SHA256
+	help
+	  This option sets the default SCTP cookie authentication method, for
+	  when a method hasn't been explicitly selected via the
+	  net.sctp.cookie_hmac_alg sysctl.
+
+	  If unsure, choose the default (HMAC-SHA256).
+
+config SCTP_DEFAULT_COOKIE_HMAC_SHA256
+	bool "HMAC-SHA256"
+
+config SCTP_DEFAULT_COOKIE_HMAC_NONE
+	bool "None"
+
+endchoice
+
+config INET_SCTP_DIAG
+	depends on INET_DIAG
+	def_tristate INET_DIAG
+
+
+endif # IP_SCTP