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, 72 insertions, 0 deletions

diff --git a/drivers/scsi/aacraid/nark.c b/drivers/scsi/aacraid/nark.c
new file mode 100644
index 000000000..4745a99fb
--- /dev/null
+++ b/drivers/scsi/aacraid/nark.c
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	Adaptec AAC series RAID controller driver
+ *
+ * based on the old aacraid driver that is..
+ * Adaptec aacraid device driver for Linux.
+ *
+ * Copyright (c) 2000-2010 Adaptec, Inc.
+ *               2010-2015 PMC-Sierra, Inc. (aacraid@pmc-sierra.com)
+ *		 2016-2017 Microsemi Corp. (aacraid@microsemi.com)
+ *
+ * Module Name:
+ *  nark.c
+ *
+ * Abstract: Hardware Device Interface for NEMER/ARK
+ */
+
+#include <linux/pci.h>
+#include <linux/blkdev.h>
+
+#include <scsi/scsi_host.h>
+
+#include "aacraid.h"
+
+/**
+ *	aac_nark_ioremap
+ *	@dev: device to ioremap
+ *	@size: mapping resize request
+ *
+ */
+static int aac_nark_ioremap(struct aac_dev * dev, u32 size)
+{
+	if (!size) {
+		iounmap(dev->regs.rx);
+		dev->regs.rx = NULL;
+		iounmap(dev->base);
+		dev->base = NULL;
+		return 0;
+	}
+	dev->base_start = pci_resource_start(dev->pdev, 2);
+	dev->regs.rx = ioremap((u64)pci_resource_start(dev->pdev, 0) |
+	  ((u64)pci_resource_start(dev->pdev, 1) << 32),
+	  sizeof(struct rx_registers) - sizeof(struct rx_inbound));
+	dev->base = NULL;
+	if (dev->regs.rx == NULL)
+		return -1;
+	dev->base = ioremap(dev->base_start, size);
+	if (dev->base == NULL) {
+		iounmap(dev->regs.rx);
+		dev->regs.rx = NULL;
+		return -1;
+	}
+	dev->IndexRegs = &((struct rx_registers __iomem *)dev->base)->IndexRegs;
+	return 0;
+}
+
+/**
+ *	aac_nark_init	-	initialize an NEMER/ARK Split Bar card
+ *	@dev: device to configure
+ *
+ */
+
+int aac_nark_init(struct aac_dev * dev)
+{
+	/*
+	 *	Fill in the function dispatch table.
+	 */
+	dev->a_ops.adapter_ioremap = aac_nark_ioremap;
+	dev->a_ops.adapter_comm = aac_rx_select_comm;
+
+	return _aac_rx_init(dev);
+}