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, 293 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinctrl-generic.c b/drivers/pinctrl/pinctrl-generic.c
new file mode 100644
index 000000000..fd6bdb740
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-generic.c
@@ -0,0 +1,293 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#define pr_fmt(fmt) "generic pinconfig core: " fmt
+
+#include <linux/array_size.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinctrl.h>
+
+#include "core.h"
+#include "pinconf.h"
+#include "pinctrl-utils.h"
+#include "pinmux.h"
+
+int pinctrl_generic_to_map(struct pinctrl_dev *pctldev, struct device_node *parent,
+			   struct device_node *np, struct pinctrl_map **maps,
+			   unsigned int *num_maps, unsigned int *num_reserved_maps,
+			   const char **group_names, unsigned int ngroups,
+			   void *data, unsigned int *pins, unsigned int npins)
+{
+	struct device *dev = pctldev->dev;
+	unsigned int num_configs;
+	const char *group_name;
+	unsigned long *configs;
+	int ret, reserve = 1;
+
+	group_name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn.%pOFn", parent, np);
+	if (!group_name)
+		return -ENOMEM;
+
+	group_names[ngroups] = group_name;
+
+	ret = pinctrl_utils_reserve_map(pctldev, maps, num_reserved_maps, num_maps, reserve);
+	if (ret)
+		return ret;
+
+	ret = pinctrl_utils_add_map_mux(pctldev, maps, num_reserved_maps, num_maps, group_name,
+					parent->name);
+	if (ret < 0)
+		goto err_free_map;
+
+	ret = pinctrl_generic_add_group(pctldev, group_name, pins, npins, data);
+	if (ret < 0) {
+		dev_err_probe(dev, ret, "failed to add group %s: %d\n",
+				     group_name, ret);
+		goto err_free_map;
+	}
+
+	ret = pinconf_generic_parse_dt_config(np, pctldev, &configs, &num_configs);
+	if (ret) {
+		dev_err_probe(dev, ret, "failed to parse pin config of group %s\n",
+			group_name);
+		goto err_free_map;
+	}
+
+	if (num_configs == 0)
+		return 0;
+
+	ret = pinctrl_utils_reserve_map(pctldev, maps, num_reserved_maps, num_maps, reserve);
+	if (ret)
+		goto err_free_map;
+
+	ret = pinctrl_utils_add_map_configs(pctldev, maps, num_reserved_maps, num_maps, group_name,
+					    configs,
+			num_configs, PIN_MAP_TYPE_CONFIGS_GROUP);
+	kfree(configs);
+	if (ret)
+		goto err_free_map;
+
+	return 0;
+
+err_free_map:
+	pinctrl_utils_free_map(pctldev, *maps, *num_maps);
+	*maps = NULL;
+	*num_maps = 0;
+	*num_reserved_maps = 0;
+	return ret;
+};
+EXPORT_SYMBOL_GPL(pinctrl_generic_to_map);
+
+static int pinctrl_generic_pins_function_dt_subnode_to_map(struct pinctrl_dev *pctldev,
+							   struct device_node *parent,
+							   struct device_node *np,
+							   struct pinctrl_map **maps,
+							   unsigned int *num_maps,
+							   unsigned int *num_reserved_maps,
+							   const char **group_names,
+							   unsigned int ngroups)
+{
+	struct device *dev = pctldev->dev;
+	unsigned int pin, *pins;
+	const char **functions;
+	int npins, ret;
+
+	npins = of_property_count_u32_elems(np, "pins");
+
+	if (npins < 1) {
+		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
+			parent, np, npins);
+		return npins;
+	}
+
+	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
+	if (!pins)
+		return -ENOMEM;
+
+	functions = devm_kcalloc(dev, npins, sizeof(*functions), GFP_KERNEL);
+	if (!functions)
+		return -ENOMEM;
+
+	for (int i = 0; i < npins; i++) {
+		ret = of_property_read_u32_index(np, "pins", i, &pin);
+		if (ret)
+			return ret;
+
+		pins[i] = pin;
+
+		ret = of_property_read_string(np, "function", &functions[i]);
+		if (ret)
+			return ret;
+	}
+
+	return pinctrl_generic_to_map(pctldev, parent, np, maps, num_maps,
+				      num_reserved_maps, group_names, ngroups,
+				      functions, pins, npins);
+}
+
+static int pinctrl_generic_pinmux_dt_subnode_to_map(struct pinctrl_dev *pctldev,
+						    struct device_node *parent,
+						    struct device_node *np,
+						    struct pinctrl_map **maps,
+						    unsigned int *num_maps,
+						    unsigned int *num_reserved_maps,
+						    const char **group_names,
+						    unsigned int ngroups)
+{
+	struct device *dev = pctldev->dev;
+	unsigned int *pins, *muxes;
+	int npins, ret;
+
+	npins = of_property_count_u32_elems(np, "pinmux");
+
+	if (npins < 1) {
+		dev_err(dev, "invalid pinctrl group %pOFn.%pOFn %d\n",
+			parent, np, npins);
+		return npins;
+	}
+
+	pins = devm_kcalloc(dev, npins, sizeof(*pins), GFP_KERNEL);
+	if (!pins)
+		return -ENOMEM;
+
+	muxes = devm_kcalloc(dev, npins, sizeof(*muxes), GFP_KERNEL);
+	if (!muxes)
+		return -ENOMEM;
+
+	for (int i = 0; i < npins; i++) {
+		unsigned int pinmux;
+
+		ret = of_property_read_u32_index(np, "pinmux", i, &pinmux);
+		if (ret)
+			return ret;
+
+		pins[i] = pinmux >> 16;
+		muxes[i] = pinmux & GENMASK(15, 0);
+	}
+
+	return pinctrl_generic_to_map(pctldev, parent, np, maps, num_maps,
+				      num_reserved_maps, group_names, ngroups,
+				      muxes, pins, npins);
+}
+
+static int pinctrl_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
+					  struct device_node *np,
+					  struct pinctrl_map **maps,
+					  unsigned int *num_maps,
+					  int (dt_subnode_to_map)(
+						  struct pinctrl_dev *,
+						  struct device_node *,
+						  struct device_node *,
+						  struct pinctrl_map **,
+						  unsigned int *,
+						  unsigned int *,
+						  const char **,
+						  unsigned int))
+{
+	struct device *dev = pctldev->dev;
+	struct device_node *child_np;
+	const char **group_names;
+	unsigned int num_reserved_maps = 0;
+	int ngroups = 0;
+	int ret;
+
+	*maps = NULL;
+	*num_maps = 0;
+
+	/*
+	 * Check if this is actually the pins node, or a parent containing
+	 * multiple pins nodes.
+	 */
+	if (!of_property_present(np, "pins"))
+		goto parent;
+
+	group_names = devm_kcalloc(dev, 1, sizeof(*group_names), GFP_KERNEL);
+	if (!group_names)
+		return -ENOMEM;
+
+	ret = dt_subnode_to_map(pctldev, np, np, maps, num_maps,
+				&num_reserved_maps, group_names, ngroups);
+	if (ret) {
+		pinctrl_utils_free_map(pctldev, *maps, *num_maps);
+		return dev_err_probe(dev, ret, "error figuring out mappings for %s\n", np->name);
+	}
+
+	ret = pinmux_generic_add_function(pctldev, np->name, group_names, 1, NULL);
+	if (ret < 0) {
+		pinctrl_utils_free_map(pctldev, *maps, *num_maps);
+		return dev_err_probe(dev, ret, "error adding function %s\n", np->name);
+	}
+
+	return 0;
+
+parent:
+	for_each_available_child_of_node(np, child_np)
+		ngroups += 1;
+
+	group_names = devm_kcalloc(dev, ngroups, sizeof(*group_names), GFP_KERNEL);
+	if (!group_names)
+		return -ENOMEM;
+
+	ngroups = 0;
+	for_each_available_child_of_node_scoped(np, child_np) {
+		ret = dt_subnode_to_map(pctldev, np, child_np, maps, num_maps,
+					&num_reserved_maps, group_names, ngroups);
+		if (ret) {
+			pinctrl_utils_free_map(pctldev, *maps, *num_maps);
+			return dev_err_probe(dev, ret, "error figuring out mappings for %s\n",
+					     np->name);
+		}
+
+		ngroups++;
+	}
+
+	ret = pinmux_generic_add_function(pctldev, np->name, group_names, ngroups, NULL);
+	if (ret < 0) {
+		pinctrl_utils_free_map(pctldev, *maps, *num_maps);
+		return dev_err_probe(dev, ret, "error adding function %s\n", np->name);
+	}
+
+	return 0;
+}
+
+/*
+ * For platforms that do not define groups or functions in the driver, but
+ * instead use the devicetree to describe them. This function will, unlike
+ * pinconf_generic_dt_node_to_map() etc which rely on driver defined groups
+ * and functions, create them in addition to parsing pinconf properties and
+ * adding mappings.
+ */
+int pinctrl_generic_pins_function_dt_node_to_map(struct pinctrl_dev *pctldev,
+						 struct device_node *np,
+						 struct pinctrl_map **maps,
+						 unsigned int *num_maps)
+{
+	return pinctrl_generic_dt_node_to_map(pctldev, np, maps, num_maps,
+					      &pinctrl_generic_pins_function_dt_subnode_to_map);
+}
+EXPORT_SYMBOL_GPL(pinctrl_generic_pins_function_dt_node_to_map);
+
+/*
+ * For platforms that do not define groups or functions in the driver, but
+ * instead use the devicetree to describe them. This function will, unlike
+ * pinconf_generic_dt_node_to_map() etc which rely on driver defined groups
+ * and functions, create them in addition to parsing pinconf properties and
+ * adding mappings.
+ *
+ * It assumes that the upper 16 bits of the pinmux items contain the pin
+ * and the lower 16 the mux setting.
+ */
+int pinctrl_generic_pinmux_dt_node_to_map(struct pinctrl_dev *pctldev,
+					  struct device_node *np,
+					  struct pinctrl_map **maps,
+					  unsigned int *num_maps)
+{
+	return pinctrl_generic_dt_node_to_map(pctldev, np, maps, num_maps,
+					      &pinctrl_generic_pinmux_dt_subnode_to_map);
+};
+EXPORT_SYMBOL_GPL(pinctrl_generic_pinmux_dt_node_to_map);