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, 113 insertions, 0 deletions

diff --git a/drivers/reset/reset-eic7700-hsp.c b/drivers/reset/reset-eic7700-hsp.c
new file mode 100644
index 000000000..1575ee4a2
--- /dev/null
+++ b/drivers/reset/reset-eic7700-hsp.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2026, Beijing ESWIN Computing Technology Co., Ltd..
+ * All rights reserved.
+ *
+ * ESWIN EIC7700 HSP Reset Driver
+ *
+ * Authors: Xuyang Dong <dongxuyang@eswincomputing.com>
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+
+#include <dt-bindings/reset/eswin,eic7700-hspcrg.h>
+
+/**
+ * struct eic7700_hsp_reset_data - reset controller information structure
+ * @rcdev: reset controller entity
+ * @regmap: regmap handle containing the memory-mapped reset registers
+ */
+struct eic7700_hsp_reset_data {
+	struct reset_controller_dev rcdev;
+	struct regmap *regmap;
+};
+
+struct eic7700_hsp_reg {
+	u32 reg;
+	u32 bit;
+	bool active_low;
+};
+
+static inline struct eic7700_hsp_reset_data *
+to_eic7700_hsp_reset(struct reset_controller_dev *rcdev)
+{
+	return container_of(rcdev, struct eic7700_hsp_reset_data, rcdev);
+}
+
+static const struct eic7700_hsp_reg eic7700_hsp_reset[] = {
+	[EIC7700_HSP_RST_SATA_P0]	= {0x340, BIT(0), false},
+	[EIC7700_HSP_RST_SATA_PHY]	= {0x340, BIT(1), false},
+	[EIC7700_HSP_RST_USB0]		= {0x800, BIT(24), true},
+	[EIC7700_HSP_RST_USB1]		= {0x900, BIT(24), true},
+	[EIC7700_HSP_RST_USB0_PHY]	= {0x800, BIT(25), false},
+	[EIC7700_HSP_RST_USB1_PHY]	= {0x900, BIT(25), false},
+};
+
+static int eic7700_hsp_reset_assert(struct reset_controller_dev *rcdev,
+				    unsigned long id)
+{
+	struct eic7700_hsp_reset_data *data = to_eic7700_hsp_reset(rcdev);
+
+	return regmap_assign_bits(data->regmap, eic7700_hsp_reset[id].reg,
+				  eic7700_hsp_reset[id].bit,
+				  !eic7700_hsp_reset[id].active_low);
+}
+
+static int eic7700_hsp_reset_deassert(struct reset_controller_dev *rcdev,
+				      unsigned long id)
+{
+	struct eic7700_hsp_reset_data *data = to_eic7700_hsp_reset(rcdev);
+
+	return regmap_assign_bits(data->regmap, eic7700_hsp_reset[id].reg,
+				  eic7700_hsp_reset[id].bit,
+				  eic7700_hsp_reset[id].active_low);
+}
+
+static const struct reset_control_ops eic7700_hsp_reset_ops = {
+	.assert = eic7700_hsp_reset_assert,
+	.deassert = eic7700_hsp_reset_deassert,
+};
+
+static int eic7700_hsp_reset_probe(struct auxiliary_device *adev,
+				   const struct auxiliary_device_id *id)
+{
+	struct eic7700_hsp_reset_data *data;
+	struct device *dev = &adev->dev;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->regmap = dev_get_regmap(dev->parent, NULL);
+	if (!data->regmap)
+		return dev_err_probe(dev, -ENODEV, "failed to get regmap!\n");
+
+	data->rcdev.owner = THIS_MODULE;
+	data->rcdev.ops = &eic7700_hsp_reset_ops;
+	data->rcdev.of_node = dev->parent->of_node;
+	data->rcdev.dev = dev;
+	data->rcdev.nr_resets = ARRAY_SIZE(eic7700_hsp_reset);
+
+	return devm_reset_controller_register(dev, &data->rcdev);
+}
+
+static const struct auxiliary_device_id eic7700_hsp_reset_ids[] = {
+	{ .name = "clk_eic7700_hsp.hsp-reset", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(auxiliary, eic7700_hsp_reset_ids);
+
+static struct auxiliary_driver eic7700_hsp_reset_driver = {
+	.probe	= eic7700_hsp_reset_probe,
+	.id_table = eic7700_hsp_reset_ids,
+};
+
+module_auxiliary_driver(eic7700_hsp_reset_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Xuyang Dong <dongxuyang@eswincomputing.com>");
+MODULE_DESCRIPTION("ESWIN EIC7700 HSP Reset Controller Driver");