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, 56 insertions, 0 deletions

diff --git a/drivers/fwctl/Kconfig b/drivers/fwctl/Kconfig
new file mode 100644
index 000000000..cac38cf79
--- /dev/null
+++ b/drivers/fwctl/Kconfig
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig FWCTL
+	tristate "fwctl device firmware access framework"
+	help
+	  fwctl provides a userspace API for restricted access to communicate
+	  with on-device firmware. The communication channel is intended to
+	  support a wide range of lockdown compatible device behaviors including
+	  manipulating device FLASH, debugging, and other activities that don't
+	  fit neatly into an existing subsystem.
+
+if FWCTL
+
+config RUST_FWCTL_ABSTRACTIONS
+	bool "Rust fwctl abstractions"
+	depends on RUST && FWCTL=y
+	help
+	  This enables the Rust abstractions for the fwctl device firmware
+	  access framework. It provides safe wrappers around struct fwctl_device
+	  and struct fwctl_uctx, allowing Rust drivers to register fwctl devices
+	  and implement their control and RPC logic in safe Rust.
+
+	  If unsure, say N.
+
+config FWCTL_BNXT
+	tristate "bnxt control fwctl driver"
+	depends on BNXT
+	help
+	  BNXT provides interface for the user process to access the debug and
+	  configuration registers of the Broadcom NIC hardware family.
+	  This will allow configuration and debug tools to work out of the box on
+	  mainstream kernel.
+
+	  If you don't know what to do here, say N.
+
+config FWCTL_MLX5
+	tristate "mlx5 ConnectX control fwctl driver"
+	depends on MLX5_CORE
+	help
+	  MLX5 provides interface for the user process to access the debug and
+	  configuration registers of the ConnectX hardware family
+	  (NICs, PCI switches and SmartNIC SoCs).
+	  This will allow configuration and debug tools to work out of the box on
+	  mainstream kernel.
+
+	  If you don't know what to do here, say N.
+
+config FWCTL_PDS
+	tristate "AMD/Pensando pds fwctl driver"
+	depends on PDS_CORE
+	help
+	  The pds_fwctl driver provides an fwctl interface for a user process
+	  to access the debug and configuration information of the AMD/Pensando
+	  DSC hardware family.
+
+	  If you don't know what to do here, say N.
+endif