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, 36 insertions, 0 deletions

diff --git a/drivers/reset/spacemit/Kconfig b/drivers/reset/spacemit/Kconfig
new file mode 100644
index 000000000..545d6b41c
--- /dev/null
+++ b/drivers/reset/spacemit/Kconfig
@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menu "Reset support for SpacemiT platforms"
+	depends on ARCH_SPACEMIT || COMPILE_TEST
+
+config RESET_SPACEMIT_COMMON
+	tristate
+	select AUXILIARY_BUS
+	help
+	  Common reset controller infrastructure for SpacemiT SoCs.
+	  This provides shared code and helper functions used by
+	  reset drivers for various SpacemiT SoC families.
+
+config RESET_SPACEMIT_K1
+	tristate "Support for SpacemiT K1 SoC"
+	depends on SPACEMIT_K1_CCU
+	select RESET_SPACEMIT_COMMON
+	default SPACEMIT_K1_CCU
+	help
+	  Support for reset controller in SpacemiT K1 SoC.
+	  This driver works with the SpacemiT K1 clock controller
+	  unit (CCU) driver to provide reset control functionality
+	  for various peripherals and subsystems in the SoC.
+
+config RESET_SPACEMIT_K3
+	tristate "Support for SpacemiT K3 SoC"
+	depends on SPACEMIT_K3_CCU
+	select RESET_SPACEMIT_COMMON
+	default SPACEMIT_K3_CCU
+	help
+	  Support for reset controller in SpacemiT K3 SoC.
+	  This driver works with the SpacemiT K3 clock controller
+	  unit (CCU) driver to provide reset control functionality
+	  for various peripherals and subsystems in the SoC.
+
+endmenu