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, 31 insertions, 0 deletions

diff --git a/net/smc/Kconfig b/net/smc/Kconfig
new file mode 100644
index 000000000..277ef504b
--- /dev/null
+++ b/net/smc/Kconfig
@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config SMC
+	tristate "SMC socket protocol family"
+	depends on INET && INFINIBAND && DIBS
+	help
+	  SMC-R provides a "sockets over RDMA" solution making use of
+	  RDMA over Converged Ethernet (RoCE) technology to upgrade
+	  AF_INET TCP connections transparently.
+	  The Linux implementation of the SMC-R solution is designed as
+	  a separate socket family SMC.
+
+	  Select this option if you want to run SMC socket applications
+
+config SMC_DIAG
+	tristate "SMC: socket monitoring interface"
+	depends on SMC
+	help
+	  Support for SMC socket monitoring interface used by tools such as
+	  smcss.
+
+	  if unsure, say Y.
+
+config SMC_HS_CTRL_BPF
+	bool "Generic eBPF hook for SMC handshake flow"
+	depends on SMC && BPF_JIT && BPF_SYSCALL
+	default y
+	help
+	  SMC_HS_CTRL_BPF enables support to register generic eBPF hook for SMC
+	  handshake flow, which offer much greater flexibility in modifying the behavior
+	  of the SMC protocol stack compared to a complete kernel-based approach. Select
+	  this option if you want filtring the handshake process via eBPF programs.