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, 22 insertions, 0 deletions

diff --git a/drivers/phy/microchip/Kconfig b/drivers/phy/microchip/Kconfig
new file mode 100644
index 000000000..2e6d12247
--- /dev/null
+++ b/drivers/phy/microchip/Kconfig
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Microchip devices
+#
+
+config PHY_SPARX5_SERDES
+	tristate "Microchip Sparx5 SerDes PHY driver"
+	select GENERIC_PHY
+	depends on ARCH_SPARX5 || ARCH_LAN969X || COMPILE_TEST
+	depends on OF
+	depends on HAS_IOMEM
+	help
+	  Enable this for support of the 10G/25G SerDes on Microchip Sparx5.
+
+config PHY_LAN966X_SERDES
+	tristate "SerDes PHY driver for Microchip LAN966X"
+	select GENERIC_PHY
+	depends on SOC_LAN966 || MCHP_LAN966X_PCI || COMPILE_TEST
+	depends on OF
+	depends on MFD_SYSCON
+	help
+	  Enable this for supporting SerDes muxing with Microchip LAN966X