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, 58 insertions, 0 deletions

diff --git a/drivers/dma/sh/Kconfig b/drivers/dma/sh/Kconfig
new file mode 100644
index 000000000..a16c7e83b
--- /dev/null
+++ b/drivers/dma/sh/Kconfig
@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# DMA engine configuration for sh
+#
+
+config RENESAS_DMA
+	bool
+	select DMA_ENGINE
+
+#
+# DMA Engine Helpers
+#
+
+config SH_DMAE_BASE
+	bool "Renesas SuperH DMA Engine support"
+	depends on SUPERH || COMPILE_TEST
+	depends on !SUPERH || SH_DMA
+	depends on !SH_DMA_API
+	default SUPERH || SH_DMA
+	select RENESAS_DMA
+	help
+	  Enable support for the Renesas SuperH DMA controllers.
+
+#
+# DMA Controllers
+#
+
+config SH_DMAE
+	tristate "Renesas SuperH DMAC support"
+	depends on SH_DMAE_BASE
+	help
+	  Enable support for the Renesas SuperH DMA controllers.
+
+config RCAR_DMAC
+	tristate "Renesas R-Car Gen{2,3} and RZ/G{1,2} DMA Controller"
+	depends on ARCH_RENESAS || COMPILE_TEST
+	select RENESAS_DMA
+	help
+	  This driver supports the general purpose DMA controller found in the
+	  Renesas R-Car Gen{2,3} and RZ/G{1,2} SoCs.
+
+config RENESAS_USB_DMAC
+	tristate "Renesas USB-DMA Controller"
+	depends on ARCH_RENESAS || COMPILE_TEST
+	select RENESAS_DMA
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  This driver supports the USB-DMA controller found in the Renesas
+	  SoCs.
+
+config RZ_DMAC
+	tristate "Renesas RZ DMA Controller"
+	depends on ARCH_RENESAS || COMPILE_TEST
+	select RENESAS_DMA
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  This driver supports the general purpose DMA controller typically
+	  found in the Renesas RZ SoC variants.