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, 33 insertions, 0 deletions

diff --git a/drivers/scsi/libsas/Kconfig b/drivers/scsi/libsas/Kconfig
new file mode 100644
index 000000000..c640535d1
--- /dev/null
+++ b/drivers/scsi/libsas/Kconfig
@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Kernel configuration file for the SAS Class
+#
+# Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
+# Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
+#
+
+config SCSI_SAS_LIBSAS
+	tristate "SAS Domain Transport Attributes"
+	depends on SCSI
+	select SCSI_SAS_ATTRS
+	help
+	  This provides transport specific helpers for SAS drivers which
+	  use the domain device construct (like the aic94xxx).
+
+config SCSI_SAS_ATA
+	bool "ATA support for libsas (requires libata)"
+	depends on SCSI_SAS_LIBSAS
+	depends on ATA = y || ATA = SCSI_SAS_LIBSAS
+	select SATA_HOST
+	help
+		Builds in ATA support into libsas.  Will necessitate
+		the loading of libata along with libsas.
+
+config SCSI_SAS_HOST_SMP
+	bool "Support for SMP interpretation for SAS hosts"
+	default y
+	depends on SCSI_SAS_LIBSAS
+	help
+		Allows sas hosts to receive SMP frames.  Selecting this
+		option builds an SMP interpreter into libsas.  Say
+		N here if you want to save the few kb this consumes.