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, 73 insertions, 0 deletions

diff --git a/drivers/nfc/Kconfig b/drivers/nfc/Kconfig
new file mode 100644
index 000000000..288c6f1c6
--- /dev/null
+++ b/drivers/nfc/Kconfig
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Near Field Communication (NFC) devices
+#
+
+menu "Near Field Communication (NFC) devices"
+	depends on NFC
+
+config NFC_TRF7970A
+	tristate "Texas Instruments TRF7970a NFC driver"
+	depends on SPI && NFC_DIGITAL && GPIOLIB
+	help
+	  This option enables the NFC driver for Texas Instruments' TRF7970a
+	  device. Such device supports 5 different protocols: ISO14443A,
+	  ISO14443B, FeLiCa, ISO15693 and ISO18000-3.
+
+	  Say Y here to compile support for TRF7970a into the kernel or
+	  say M  to compile it as a module. The module will be called
+	  trf7970a.ko.
+
+config NFC_MEI_PHY
+	tristate "MEI bus NFC device support"
+	depends on INTEL_MEI && NFC_HCI
+	help
+	  This adds support to use an mei bus nfc device. Select this if you
+	  will use an HCI NFC driver for an NFC chip connected behind an
+	  Intel's Management Engine chip.
+
+	  If unsure, say N.
+
+config NFC_SIM
+	tristate "NFC hardware simulator driver"
+	depends on NFC_DIGITAL
+	help
+	  This driver declares two virtual NFC devices supporting NFC-DEP
+	  protocol. An LLCP connection can be established between them and
+	  all packets sent from one device is sent back to the other, acting as
+	  loopback devices.
+
+	  If unsure, say N.
+
+config NFC_PORT100
+	tristate "Sony NFC Port-100 Series USB device support"
+	depends on USB
+	depends on NFC_DIGITAL
+	help
+	  This adds support for Sony Port-100 chip based USB devices such as the
+	  RC-S380 dongle.
+
+	  If unsure, say N.
+
+config NFC_VIRTUAL_NCI
+	tristate "NCI device simulator driver"
+	depends on NFC_NCI
+	help
+	  NCI virtual device simulates a NCI device to the user.
+	  It can be used to validate the NCI module and applications.
+	  This driver supports communication between the virtual NCI device and
+	  module.
+
+	  If unsure, say N.
+
+source "drivers/nfc/fdp/Kconfig"
+source "drivers/nfc/pn544/Kconfig"
+source "drivers/nfc/pn533/Kconfig"
+source "drivers/nfc/microread/Kconfig"
+source "drivers/nfc/nfcmrvl/Kconfig"
+source "drivers/nfc/st21nfca/Kconfig"
+source "drivers/nfc/st-nci/Kconfig"
+source "drivers/nfc/nxp-nci/Kconfig"
+source "drivers/nfc/s3fwrn5/Kconfig"
+source "drivers/nfc/st95hf/Kconfig"
+endmenu