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/interconnect/imx/imx.h b/drivers/interconnect/imx/imx.h
new file mode 100644
index 000000000..d4d0e9888
--- /dev/null
+++ b/drivers/interconnect/imx/imx.h
@@ -0,0 +1,113 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Interconnect framework driver for i.MX SoC
+ *
+ * Copyright (c) 2019, BayLibre
+ * Copyright (c) 2019-2020, NXP
+ * Author: Alexandre Bailon <abailon@baylibre.com>
+ * Author: Leonard Crestez <leonard.crestez@nxp.com>
+ */
+#ifndef __DRIVERS_INTERCONNECT_IMX_H
+#define __DRIVERS_INTERCONNECT_IMX_H
+
+#include <linux/args.h>
+#include <linux/bits.h>
+#include <linux/types.h>
+
+#include <linux/interconnect-provider.h>
+
+struct platform_device;
+
+#define IMX_ICC_MAX_LINKS	4
+
+/*
+ * High throughput priority level in Regulator mode
+ * Read Priority in Fixed/Limiter mode
+ */
+#define PRIORITY0_SHIFT	0
+/*
+ * Low throughput priority level in Regulator mode
+ * Write Priority in Fixed/Limiter mode
+ */
+#define PRIORITY1_SHIFT	8
+#define PRIORITY_MASK		0x7
+
+#define PRIORITY_COMP_MARK	BIT(31)	/* Must set */
+
+#define IMX_NOC_MODE_FIXED		0
+#define IMX_NOC_MODE_LIMITER		1
+#define IMX_NOC_MODE_BYPASS		2
+#define IMX_NOC_MODE_REGULATOR		3
+#define IMX_NOC_MODE_UNCONFIGURED	0xFF
+
+#define IMX_NOC_PRIO_REG	0x8
+#define IMX_NOC_MODE_REG	0xC
+#define IMX_NOC_BANDWIDTH_REG	0x10
+#define IMX_NOC_SATURATION	0x14
+#define IMX_NOC_EXT_CTL_REG	0x18
+
+struct imx_icc_provider {
+	void __iomem *noc_base;
+	struct icc_provider provider;
+};
+
+/*
+ * struct imx_icc_node_adj - Describe a dynamic adjustable node
+ */
+struct imx_icc_node_adj_desc {
+	unsigned int bw_mul, bw_div;
+	const char *phandle_name;
+	bool main_noc;
+};
+
+/*
+ * struct imx_icc_node - Describe an interconnect node
+ * @name: name of the node
+ * @id: an unique id to identify the node
+ * @links: an array of slaves' node id
+ * @num_links: number of id defined in links
+ */
+struct imx_icc_node_desc {
+	const char *name;
+	u16 id;
+	u16 links[IMX_ICC_MAX_LINKS];
+	u16 num_links;
+	const struct imx_icc_node_adj_desc *adj;
+};
+
+/*
+ * struct imx_icc_noc_setting - Describe an interconnect node setting
+ * @reg: register offset inside the NoC
+ * @prio_level: priority level
+ * @mode: functional mode
+ * @ext_control: external input control
+ */
+struct imx_icc_noc_setting {
+	u32 reg;
+	u32 prio_level;
+	u32 mode;
+	u32 ext_control;
+};
+
+#define DEFINE_BUS_INTERCONNECT(_name, _id, _adj, ...)			\
+	{								\
+		.id = _id,						\
+		.name = _name,						\
+		.adj = _adj,						\
+		.num_links = COUNT_ARGS(__VA_ARGS__),			\
+		.links = { __VA_ARGS__ },				\
+	}
+
+#define DEFINE_BUS_MASTER(_name, _id, _dest_id)				\
+	DEFINE_BUS_INTERCONNECT(_name, _id, NULL, _dest_id)
+
+#define DEFINE_BUS_SLAVE(_name, _id, _adj)				\
+	DEFINE_BUS_INTERCONNECT(_name, _id, _adj)
+
+int imx_icc_register(struct platform_device *pdev,
+		     struct imx_icc_node_desc *nodes,
+		     int nodes_count,
+		     struct imx_icc_noc_setting *noc_settings);
+void imx_icc_unregister(struct platform_device *pdev);
+
+#endif /* __DRIVERS_INTERCONNECT_IMX_H */