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, 136 insertions, 0 deletions

diff --git a/drivers/nvme/host/Kconfig b/drivers/nvme/host/Kconfig
new file mode 100644
index 000000000..31974c7dd
--- /dev/null
+++ b/drivers/nvme/host/Kconfig
@@ -0,0 +1,136 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NVME_CORE
+	tristate
+
+config BLK_DEV_NVME
+	tristate "NVM Express block device"
+	depends on PCI && BLOCK
+	select NVME_CORE
+	help
+	  The NVM Express driver is for solid state drives directly
+	  connected to the PCI or PCI Express bus.  If you know you
+	  don't have one of these, it is safe to answer N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called nvme.
+
+config NVME_MULTIPATH
+	bool "NVMe multipath support"
+	depends on NVME_CORE
+	help
+	  This option controls support for multipath access to NVMe
+	  subsystems. If this option is enabled support for NVMe multipath
+	  access is included in the kernel. If this option is disabled support
+	  for NVMe multipath access is excluded from the kernel. When this
+	  option is disabled each controller/namespace receives its
+	  own /dev/nvmeXnY device entry and NVMe multipath access is
+	  not supported.
+
+	  If unsure, say Y.
+
+config NVME_VERBOSE_ERRORS
+	bool "NVMe verbose error reporting"
+	depends on NVME_CORE
+	help
+	   This option enables verbose reporting for NVMe errors. The
+	   error translation table will grow the kernel image size by
+	   about 4 KB.
+
+config NVME_HWMON
+	bool "NVMe hardware monitoring"
+	depends on (NVME_CORE=y && HWMON=y) || (NVME_CORE=m && HWMON)
+	help
+	  This provides support for NVMe hardware monitoring. If enabled,
+	  a hardware monitoring device will be created for each NVMe drive
+	  in the system.
+
+config NVME_FABRICS
+	select NVME_CORE
+	select NVME_KEYRING if NVME_TCP_TLS
+	tristate
+
+config NVME_RDMA
+	tristate "NVM Express over Fabrics RDMA host driver"
+	depends on INFINIBAND && INFINIBAND_ADDR_TRANS && BLOCK
+	select NVME_FABRICS
+	select SG_POOL
+	help
+	  This provides support for the NVMe over Fabrics protocol using
+	  the RDMA (Infiniband, RoCE, iWarp) transport.  This allows you
+	  to use remote block devices exported using the NVMe protocol set.
+
+	  To configure a NVMe over Fabrics controller use the nvme-cli tool
+	  from https://github.com/linux-nvme/nvme-cli.
+
+	  If unsure, say N.
+
+config NVME_FC
+	tristate "NVM Express over Fabrics FC host driver"
+	depends on BLOCK
+	depends on HAS_DMA
+	select NVME_FABRICS
+	select SG_POOL
+	help
+	  This provides support for the NVMe over Fabrics protocol using
+	  the FC transport.  This allows you to use remote block devices
+	  exported using the NVMe protocol set.
+
+	  To configure a NVMe over Fabrics controller use the nvme-cli tool
+	  from https://github.com/linux-nvme/nvme-cli.
+
+	  If unsure, say N.
+
+config NVME_TCP
+	tristate "NVM Express over Fabrics TCP host driver"
+	depends on INET
+	depends on BLOCK
+	select CRC32
+	select NET_CRC32C
+	select NVME_FABRICS
+	help
+	  This provides support for the NVMe over Fabrics protocol using
+	  the TCP transport.  This allows you to use remote block devices
+	  exported using the NVMe protocol set.
+
+	  To configure a NVMe over Fabrics controller use the nvme-cli tool
+	  from https://github.com/linux-nvme/nvme-cli.
+
+	  If unsure, say N.
+
+config NVME_TCP_TLS
+	bool "NVMe over Fabrics TCP TLS encryption support"
+	depends on NVME_TCP
+	select NET_HANDSHAKE
+	select KEYS
+	select TLS
+	help
+	  Enables TLS encryption for NVMe TCP using the netlink handshake API.
+
+	  The TLS handshake daemon is available at
+	  https://github.com/oracle/ktls-utils.
+
+	  If unsure, say N.
+
+config NVME_HOST_AUTH
+	bool "NVMe over Fabrics In-Band Authentication in host side"
+	depends on NVME_CORE
+	select NVME_AUTH
+	select NVME_KEYRING
+	help
+	  This provides support for NVMe over Fabrics In-Band Authentication in
+	  host side.
+
+	  If unsure, say N.
+
+config NVME_APPLE
+	tristate "Apple ANS2 NVM Express host driver"
+	depends on OF && BLOCK
+	depends on APPLE_RTKIT && APPLE_SART
+	depends on ARCH_APPLE || COMPILE_TEST
+	select NVME_CORE
+	help
+	  This provides support for the NVMe controller embedded in Apple SoCs
+	  such as the M1.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called nvme-apple.