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, 599 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinctrl-scmi.c b/drivers/pinctrl/pinctrl-scmi.c
new file mode 100644
index 000000000..1bb36ca47
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-scmi.c
@@ -0,0 +1,599 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Power Interface (SCMI) Protocol based pinctrl driver
+ *
+ * Copyright (C) 2024 EPAM
+ * Copyright 2024 NXP
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/scmi_protocol.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <linux/pinctrl/machine.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+
+#include "pinctrl-utils.h"
+#include "core.h"
+#include "pinconf.h"
+
+#define DRV_NAME "scmi-pinctrl"
+
+/* Define num configs, if not large than 4 use stack, else use kcalloc() */
+#define SCMI_NUM_CONFIGS	4
+
+static const struct scmi_pinctrl_proto_ops *pinctrl_ops;
+
+struct scmi_pinctrl {
+	struct device *dev;
+	struct scmi_protocol_handle *ph;
+	struct pinctrl_dev *pctldev;
+	struct pinctrl_desc pctl_desc;
+	struct pinfunction *functions;
+	unsigned int nr_functions;
+};
+
+static int pinctrl_scmi_get_groups_count(struct pinctrl_dev *pctldev)
+{
+	struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+
+	return pinctrl_ops->count_get(pmx->ph, GROUP_TYPE);
+}
+
+static const char *pinctrl_scmi_get_group_name(struct pinctrl_dev *pctldev,
+					       unsigned int selector)
+{
+	int ret;
+	const char *name;
+	struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+
+	ret = pinctrl_ops->name_get(pmx->ph, selector, GROUP_TYPE, &name);
+	if (ret) {
+		dev_err(pmx->dev, "get name failed with err %d", ret);
+		return NULL;
+	}
+
+	return name;
+}
+
+static int pinctrl_scmi_get_group_pins(struct pinctrl_dev *pctldev,
+				       unsigned int selector,
+				       const unsigned int **pins,
+				       unsigned int *num_pins)
+{
+	struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+
+	return pinctrl_ops->group_pins_get(pmx->ph, selector, pins, num_pins);
+}
+
+static const struct pinctrl_ops pinctrl_scmi_pinctrl_ops = {
+	.get_groups_count = pinctrl_scmi_get_groups_count,
+	.get_group_name = pinctrl_scmi_get_group_name,
+	.get_group_pins = pinctrl_scmi_get_group_pins,
+#ifdef CONFIG_OF
+	.dt_node_to_map = pinconf_generic_dt_node_to_map_all,
+	.dt_free_map = pinconf_generic_dt_free_map,
+#endif
+};
+
+static int pinctrl_scmi_get_functions_count(struct pinctrl_dev *pctldev)
+{
+	struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+
+	return pinctrl_ops->count_get(pmx->ph, FUNCTION_TYPE);
+}
+
+static const char *pinctrl_scmi_get_function_name(struct pinctrl_dev *pctldev,
+						  unsigned int selector)
+{
+	int ret;
+	const char *name;
+	struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+
+	ret = pinctrl_ops->name_get(pmx->ph, selector, FUNCTION_TYPE, &name);
+	if (ret) {
+		dev_err(pmx->dev, "get name failed with err %d", ret);
+		return NULL;
+	}
+
+	return name;
+}
+
+static int pinctrl_scmi_get_function_groups(struct pinctrl_dev *pctldev,
+					    unsigned int selector,
+					    const char * const **p_groups,
+					    unsigned int * const p_num_groups)
+{
+	struct pinfunction *func;
+	const unsigned int *group_ids;
+	unsigned int num_groups;
+	const char **groups;
+	int ret, i;
+	struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+
+	if (!p_groups || !p_num_groups)
+		return -EINVAL;
+
+	if (selector >= pmx->nr_functions)
+		return -EINVAL;
+
+	func = &pmx->functions[selector];
+	if (func->ngroups)
+		goto done;
+
+	ret = pinctrl_ops->function_groups_get(pmx->ph, selector, &num_groups,
+					       &group_ids);
+	if (ret) {
+		dev_err(pmx->dev, "Unable to get function groups, err %d", ret);
+		return ret;
+	}
+	if (!num_groups)
+		return -EINVAL;
+
+	groups = kcalloc(num_groups, sizeof(*groups), GFP_KERNEL);
+	if (!groups)
+		return -ENOMEM;
+
+	for (i = 0; i < num_groups; i++) {
+		groups[i] = pinctrl_scmi_get_group_name(pctldev, group_ids[i]);
+		if (!groups[i]) {
+			ret = -EINVAL;
+			goto err_free;
+		}
+	}
+
+	func->ngroups = num_groups;
+	func->groups = groups;
+done:
+	*p_groups = func->groups;
+	*p_num_groups = func->ngroups;
+
+	return 0;
+
+err_free:
+	kfree(groups);
+
+	return ret;
+}
+
+static int pinctrl_scmi_func_set_mux(struct pinctrl_dev *pctldev,
+				     unsigned int selector, unsigned int group)
+{
+	struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+
+	return pinctrl_ops->mux_set(pmx->ph, selector, group);
+}
+
+static int pinctrl_scmi_request(struct pinctrl_dev *pctldev,
+				unsigned int offset)
+{
+	struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+
+	return pinctrl_ops->pin_request(pmx->ph, offset);
+}
+
+static int pinctrl_scmi_free(struct pinctrl_dev *pctldev, unsigned int offset)
+{
+	struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+
+	return pinctrl_ops->pin_free(pmx->ph, offset);
+}
+
+static const struct pinmux_ops pinctrl_scmi_pinmux_ops = {
+	.request = pinctrl_scmi_request,
+	.free = pinctrl_scmi_free,
+	.get_functions_count = pinctrl_scmi_get_functions_count,
+	.get_function_name = pinctrl_scmi_get_function_name,
+	.get_function_groups = pinctrl_scmi_get_function_groups,
+	.set_mux = pinctrl_scmi_func_set_mux,
+};
+
+static int pinctrl_scmi_map_pinconf_type(enum pin_config_param param,
+					 enum scmi_pinctrl_conf_type *type)
+{
+	u32 arg = param;
+
+	switch (arg) {
+	case PIN_CONFIG_BIAS_BUS_HOLD:
+		*type = SCMI_PIN_BIAS_BUS_HOLD;
+		break;
+	case PIN_CONFIG_BIAS_DISABLE:
+		*type = SCMI_PIN_BIAS_DISABLE;
+		break;
+	case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
+		*type = SCMI_PIN_BIAS_HIGH_IMPEDANCE;
+		break;
+	case PIN_CONFIG_BIAS_PULL_DOWN:
+		*type = SCMI_PIN_BIAS_PULL_DOWN;
+		break;
+	case PIN_CONFIG_BIAS_PULL_PIN_DEFAULT:
+		*type = SCMI_PIN_BIAS_PULL_DEFAULT;
+		break;
+	case PIN_CONFIG_BIAS_PULL_UP:
+		*type = SCMI_PIN_BIAS_PULL_UP;
+		break;
+	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+		*type = SCMI_PIN_DRIVE_OPEN_DRAIN;
+		break;
+	case PIN_CONFIG_DRIVE_OPEN_SOURCE:
+		*type = SCMI_PIN_DRIVE_OPEN_SOURCE;
+		break;
+	case PIN_CONFIG_DRIVE_PUSH_PULL:
+		*type = SCMI_PIN_DRIVE_PUSH_PULL;
+		break;
+	case PIN_CONFIG_DRIVE_STRENGTH:
+		*type = SCMI_PIN_DRIVE_STRENGTH;
+		break;
+	case PIN_CONFIG_DRIVE_STRENGTH_UA:
+		*type = SCMI_PIN_DRIVE_STRENGTH;
+		break;
+	case PIN_CONFIG_INPUT_DEBOUNCE:
+		*type = SCMI_PIN_INPUT_DEBOUNCE;
+		break;
+	case PIN_CONFIG_INPUT_ENABLE:
+		*type = SCMI_PIN_INPUT_MODE;
+		break;
+	case PIN_CONFIG_INPUT_SCHMITT:
+		*type = SCMI_PIN_INPUT_SCHMITT;
+		break;
+	case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
+		*type = SCMI_PIN_INPUT_MODE;
+		break;
+	case PIN_CONFIG_MODE_LOW_POWER:
+		*type = SCMI_PIN_LOW_POWER_MODE;
+		break;
+	case PIN_CONFIG_OUTPUT_ENABLE:
+		*type = SCMI_PIN_OUTPUT_MODE;
+		break;
+	case PIN_CONFIG_POWER_SOURCE:
+		*type = SCMI_PIN_POWER_SOURCE;
+		break;
+	case PIN_CONFIG_SLEW_RATE:
+		*type = SCMI_PIN_SLEW_RATE;
+		break;
+	case SCMI_PIN_OEM_START ... SCMI_PIN_OEM_END:
+		*type = arg;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int pinctrl_scmi_map_pinconf_type_get(enum pin_config_param param,
+					     enum scmi_pinctrl_conf_type *type)
+{
+	if (param == PIN_CONFIG_LEVEL) {
+		*type = SCMI_PIN_INPUT_VALUE;
+		return 0;
+	}
+
+	return pinctrl_scmi_map_pinconf_type(param, type);
+}
+
+static int pinctrl_scmi_map_pinconf_type_set(enum pin_config_param param,
+					     enum scmi_pinctrl_conf_type *type)
+{
+	if (param == PIN_CONFIG_LEVEL) {
+		*type = SCMI_PIN_OUTPUT_VALUE;
+		return 0;
+	}
+
+	return pinctrl_scmi_map_pinconf_type(param, type);
+}
+
+static int pinctrl_scmi_pinconf_get(struct pinctrl_dev *pctldev,
+				    unsigned int pin, unsigned long *config)
+{
+	int ret;
+	struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+	enum pin_config_param config_type;
+	enum scmi_pinctrl_conf_type type;
+	u32 config_value;
+
+	if (!config)
+		return -EINVAL;
+
+	config_type = pinconf_to_config_param(*config);
+
+	ret = pinctrl_scmi_map_pinconf_type_get(config_type, &type);
+	if (ret)
+		return ret;
+
+	ret = pinctrl_ops->settings_get_one(pmx->ph, pin, PIN_TYPE, type,
+					    &config_value);
+	/* Convert SCMI error code to PINCTRL expected error code */
+	if (ret == -EOPNOTSUPP)
+		return -ENOTSUPP;
+	if (ret)
+		return ret;
+
+	*config = pinconf_to_config_packed(config_type, config_value);
+
+	return 0;
+}
+
+static int
+pinctrl_scmi_alloc_configs(struct pinctrl_dev *pctldev, u32 num_configs,
+			   u32 **p_config_value,
+			   enum scmi_pinctrl_conf_type **p_config_type)
+{
+	if (num_configs <= SCMI_NUM_CONFIGS)
+		return 0;
+
+	*p_config_value = kcalloc(num_configs, sizeof(**p_config_value), GFP_KERNEL);
+	if (!*p_config_value)
+		return -ENOMEM;
+
+	*p_config_type = kzalloc_objs(**p_config_type, num_configs);
+	if (!*p_config_type) {
+		kfree(*p_config_value);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void
+pinctrl_scmi_free_configs(struct pinctrl_dev *pctldev, u32 num_configs,
+			  u32 **p_config_value,
+			  enum scmi_pinctrl_conf_type **p_config_type)
+{
+	if (num_configs <= SCMI_NUM_CONFIGS)
+		return;
+
+	kfree(*p_config_value);
+	kfree(*p_config_type);
+}
+
+static int pinctrl_scmi_pinconf_set(struct pinctrl_dev *pctldev,
+				    unsigned int pin,
+				    unsigned long *configs,
+				    unsigned int num_configs)
+{
+	int i, cnt, ret;
+	struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+	enum scmi_pinctrl_conf_type config_type[SCMI_NUM_CONFIGS];
+	u32 config_value[SCMI_NUM_CONFIGS];
+	enum scmi_pinctrl_conf_type *p_config_type = config_type;
+	u32 *p_config_value = config_value;
+	enum pin_config_param param;
+
+	if (!configs || !num_configs)
+		return -EINVAL;
+
+	ret = pinctrl_scmi_alloc_configs(pctldev, num_configs, &p_config_type,
+					 &p_config_value);
+	if (ret)
+		return ret;
+
+	cnt = 0;
+	for (i = 0; i < num_configs; i++) {
+		param = pinconf_to_config_param(configs[i]);
+		if (param == PIN_CONFIG_PERSIST_STATE)
+			continue;
+		ret = pinctrl_scmi_map_pinconf_type_set(param, &p_config_type[cnt]);
+		if (ret) {
+			dev_err(pmx->dev, "Error map pinconf_type %d\n", ret);
+			goto free_config;
+		}
+		p_config_value[cnt] = pinconf_to_config_argument(configs[i]);
+		cnt++;
+	}
+
+	ret = pinctrl_ops->settings_conf(pmx->ph, pin, PIN_TYPE, cnt,
+					 p_config_type,  p_config_value);
+	if (ret)
+		dev_err(pmx->dev, "Error parsing config %d\n", ret);
+
+free_config:
+	pinctrl_scmi_free_configs(pctldev, num_configs, &p_config_type,
+				  &p_config_value);
+	return ret;
+}
+
+static int pinctrl_scmi_pinconf_group_set(struct pinctrl_dev *pctldev,
+					  unsigned int group,
+					  unsigned long *configs,
+					  unsigned int num_configs)
+{
+	int i, ret;
+	struct scmi_pinctrl *pmx =  pinctrl_dev_get_drvdata(pctldev);
+	enum scmi_pinctrl_conf_type config_type[SCMI_NUM_CONFIGS];
+	u32 config_value[SCMI_NUM_CONFIGS];
+	enum scmi_pinctrl_conf_type *p_config_type = config_type;
+	u32 *p_config_value = config_value;
+	enum pin_config_param param;
+
+	if (!configs || !num_configs)
+		return -EINVAL;
+
+	ret = pinctrl_scmi_alloc_configs(pctldev, num_configs, &p_config_type,
+					 &p_config_value);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < num_configs; i++) {
+		param = pinconf_to_config_param(configs[i]);
+		ret = pinctrl_scmi_map_pinconf_type_set(param, &p_config_type[i]);
+		if (ret) {
+			dev_err(pmx->dev, "Error map pinconf_type %d\n", ret);
+			goto free_config;
+		}
+
+		p_config_value[i] = pinconf_to_config_argument(configs[i]);
+	}
+
+	ret = pinctrl_ops->settings_conf(pmx->ph, group, GROUP_TYPE,
+					 num_configs, p_config_type,
+					 p_config_value);
+	if (ret)
+		dev_err(pmx->dev, "Error parsing config %d", ret);
+
+free_config:
+	pinctrl_scmi_free_configs(pctldev, num_configs, &p_config_type,
+				  &p_config_value);
+	return ret;
+};
+
+static int pinctrl_scmi_pinconf_group_get(struct pinctrl_dev *pctldev,
+					  unsigned int group,
+					  unsigned long *config)
+{
+	int ret;
+	struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
+	enum pin_config_param config_type;
+	enum scmi_pinctrl_conf_type type;
+	u32 config_value;
+
+	if (!config)
+		return -EINVAL;
+
+	config_type = pinconf_to_config_param(*config);
+	ret = pinctrl_scmi_map_pinconf_type_get(config_type, &type);
+	if (ret) {
+		dev_err(pmx->dev, "Error map pinconf_type %d\n", ret);
+		return ret;
+	}
+
+	ret = pinctrl_ops->settings_get_one(pmx->ph, group, GROUP_TYPE, type,
+					    &config_value);
+	/* Convert SCMI error code to PINCTRL expected error code */
+	if (ret == -EOPNOTSUPP)
+		return -ENOTSUPP;
+	if (ret)
+		return ret;
+
+	*config = pinconf_to_config_packed(config_type, config_value);
+
+	return 0;
+}
+
+static const struct pinconf_ops pinctrl_scmi_pinconf_ops = {
+	.is_generic = true,
+	.pin_config_get = pinctrl_scmi_pinconf_get,
+	.pin_config_set = pinctrl_scmi_pinconf_set,
+	.pin_config_group_set = pinctrl_scmi_pinconf_group_set,
+	.pin_config_group_get = pinctrl_scmi_pinconf_group_get,
+	.pin_config_config_dbg_show = pinconf_generic_dump_config,
+};
+
+static int pinctrl_scmi_get_pins(struct scmi_pinctrl *pmx,
+				 struct pinctrl_desc *desc)
+{
+	struct pinctrl_pin_desc *pins;
+	unsigned int npins;
+	int ret, i;
+
+	npins = pinctrl_ops->count_get(pmx->ph, PIN_TYPE);
+	/*
+	 * npins will never be zero, the scmi pinctrl driver has bailed out
+	 * if npins is zero.
+	 */
+	pins = devm_kmalloc_array(pmx->dev, npins, sizeof(*pins), GFP_KERNEL);
+	if (!pins)
+		return -ENOMEM;
+
+	for (i = 0; i < npins; i++) {
+		pins[i].number = i;
+		/*
+		 * The memory for name is handled by the scmi firmware driver,
+		 * no need free here
+		 */
+		ret = pinctrl_ops->name_get(pmx->ph, i, PIN_TYPE, &pins[i].name);
+		if (ret)
+			return dev_err_probe(pmx->dev, ret,
+					     "Can't get name for pin %d", i);
+	}
+
+	desc->npins = npins;
+	desc->pins = pins;
+	dev_dbg(pmx->dev, "got pins %u", npins);
+
+	return 0;
+}
+
+static const char * const scmi_pinctrl_blocklist[] = {
+	"fsl,imx94",
+	"fsl,imx95",
+	"fsl,imx952",
+	NULL
+};
+
+static int scmi_pinctrl_probe(struct scmi_device *sdev)
+{
+	int ret;
+	struct device *dev = &sdev->dev;
+	struct scmi_pinctrl *pmx;
+	const struct scmi_handle *handle;
+	struct scmi_protocol_handle *ph;
+
+	if (!sdev->handle)
+		return -EINVAL;
+
+	if (of_machine_compatible_match(scmi_pinctrl_blocklist))
+		return -ENODEV;
+
+	handle = sdev->handle;
+
+	pinctrl_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_PINCTRL, &ph);
+	if (IS_ERR(pinctrl_ops))
+		return PTR_ERR(pinctrl_ops);
+
+	pmx = devm_kzalloc(dev, sizeof(*pmx), GFP_KERNEL);
+	if (!pmx)
+		return -ENOMEM;
+
+	pmx->ph = ph;
+
+	pmx->dev = dev;
+	pmx->pctl_desc.name = DRV_NAME;
+	pmx->pctl_desc.owner = THIS_MODULE;
+	pmx->pctl_desc.pctlops = &pinctrl_scmi_pinctrl_ops;
+	pmx->pctl_desc.pmxops = &pinctrl_scmi_pinmux_ops;
+	pmx->pctl_desc.confops = &pinctrl_scmi_pinconf_ops;
+
+	ret = pinctrl_scmi_get_pins(pmx, &pmx->pctl_desc);
+	if (ret)
+		return ret;
+
+	ret = devm_pinctrl_register_and_init(dev, &pmx->pctl_desc, pmx,
+					     &pmx->pctldev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to register pinctrl\n");
+
+	pmx->nr_functions = pinctrl_scmi_get_functions_count(pmx->pctldev);
+	pmx->functions = devm_kcalloc(dev, pmx->nr_functions,
+				      sizeof(*pmx->functions), GFP_KERNEL);
+	if (!pmx->functions)
+		return -ENOMEM;
+
+	return pinctrl_enable(pmx->pctldev);
+}
+
+static const struct scmi_device_id scmi_id_table[] = {
+	{ SCMI_PROTOCOL_PINCTRL, "pinctrl" },
+	{ }
+};
+MODULE_DEVICE_TABLE(scmi, scmi_id_table);
+
+static struct scmi_driver scmi_pinctrl_driver = {
+	.name = DRV_NAME,
+	.probe = scmi_pinctrl_probe,
+	.id_table = scmi_id_table,
+};
+module_scmi_driver(scmi_pinctrl_driver);
+
+MODULE_AUTHOR("Oleksii Moisieiev <oleksii_moisieiev@epam.com>");
+MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>");
+MODULE_DESCRIPTION("ARM SCMI pin controller driver");
+MODULE_LICENSE("GPL");