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, 47 insertions, 0 deletions

diff --git a/drivers/dma/stm32/Kconfig b/drivers/dma/stm32/Kconfig
new file mode 100644
index 000000000..4d8d80631
--- /dev/null
+++ b/drivers/dma/stm32/Kconfig
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# STM32 DMA controllers drivers
+#
+if ARCH_STM32 || COMPILE_TEST
+
+config STM32_DMA
+	bool "STMicroelectronics STM32 DMA support"
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Enable support for the on-chip DMA controller on STMicroelectronics
+	  STM32 platforms.
+	  If you have a board based on STM32 SoC with such DMA controller
+	  and want to use DMA say Y here.
+
+config STM32_DMAMUX
+	bool "STMicroelectronics STM32 DMA multiplexer support"
+	depends on STM32_DMA
+	help
+	  Enable support for the on-chip DMA multiplexer on STMicroelectronics
+	  STM32 platforms.
+	  If you have a board based on STM32 SoC with such DMA multiplexer
+	  and want to use DMAMUX say Y here.
+
+config STM32_MDMA
+	bool "STMicroelectronics STM32 master DMA support"
+	depends on OF
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Enable support for the on-chip MDMA controller on STMicroelectronics
+	  STM32 platforms.
+	  If you have a board based on STM32 SoC with such DMA controller
+	  and want to use MDMA say Y here.
+
+config STM32_DMA3
+	tristate "STMicroelectronics STM32 DMA3 support"
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Enable support for the on-chip DMA3 controller on STMicroelectronics
+	  STM32 platforms.
+	  If you have a board based on STM32 SoC with such DMA3 controller
+	  and want to use DMA3, say Y here.
+
+endif