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, 288 insertions, 0 deletions

diff --git a/drivers/mfd/bd9571mwv.c b/drivers/mfd/bd9571mwv.c
new file mode 100644
index 000000000..db8c2963f
--- /dev/null
+++ b/drivers/mfd/bd9571mwv.c
@@ -0,0 +1,288 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ROHM BD9571MWV-M and BD9574MVF-M core driver
+ *
+ * Copyright (C) 2017 Marek Vasut <marek.vasut+renesas@gmail.com>
+ * Copyright (C) 2020 Renesas Electronics Corporation
+ *
+ * Based on the TPS65086 driver
+ */
+
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/rohm-generic.h>
+#include <linux/module.h>
+
+#include <linux/mfd/bd9571mwv.h>
+
+static const struct mfd_cell bd9571mwv_cells[] = {
+	{ .name = "bd9571mwv-regulator", },
+	{ .name = "bd9571mwv-gpio", },
+};
+
+static const struct regmap_range bd9571mwv_readable_yes_ranges[] = {
+	regmap_reg_range(BD9571MWV_VENDOR_CODE, BD9571MWV_PRODUCT_REVISION),
+	regmap_reg_range(BD9571MWV_BKUP_MODE_CNT, BD9571MWV_BKUP_MODE_CNT),
+	regmap_reg_range(BD9571MWV_AVS_SET_MONI, BD9571MWV_AVS_DVFS_VID(3)),
+	regmap_reg_range(BD9571MWV_VD18_VID, BD9571MWV_VD33_VID),
+	regmap_reg_range(BD9571MWV_DVFS_VINIT, BD9571MWV_DVFS_VINIT),
+	regmap_reg_range(BD9571MWV_DVFS_SETVMAX, BD9571MWV_DVFS_MONIVDAC),
+	regmap_reg_range(BD9571MWV_GPIO_IN, BD9571MWV_GPIO_IN),
+	regmap_reg_range(BD9571MWV_GPIO_INT, BD9571MWV_GPIO_INTMASK),
+	regmap_reg_range(BD9571MWV_INT_INTREQ, BD9571MWV_INT_INTMASK),
+};
+
+static const struct regmap_access_table bd9571mwv_readable_table = {
+	.yes_ranges	= bd9571mwv_readable_yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(bd9571mwv_readable_yes_ranges),
+};
+
+static const struct regmap_range bd9571mwv_writable_yes_ranges[] = {
+	regmap_reg_range(BD9571MWV_BKUP_MODE_CNT, BD9571MWV_BKUP_MODE_CNT),
+	regmap_reg_range(BD9571MWV_AVS_VD09_VID(0), BD9571MWV_AVS_VD09_VID(3)),
+	regmap_reg_range(BD9571MWV_DVFS_SETVID, BD9571MWV_DVFS_SETVID),
+	regmap_reg_range(BD9571MWV_GPIO_DIR, BD9571MWV_GPIO_OUT),
+	regmap_reg_range(BD9571MWV_GPIO_INT_SET, BD9571MWV_GPIO_INTMASK),
+	regmap_reg_range(BD9571MWV_INT_INTREQ, BD9571MWV_INT_INTMASK),
+};
+
+static const struct regmap_access_table bd9571mwv_writable_table = {
+	.yes_ranges	= bd9571mwv_writable_yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(bd9571mwv_writable_yes_ranges),
+};
+
+static const struct regmap_range bd9571mwv_volatile_yes_ranges[] = {
+	regmap_reg_range(BD9571MWV_DVFS_MONIVDAC, BD9571MWV_DVFS_MONIVDAC),
+	regmap_reg_range(BD9571MWV_GPIO_IN, BD9571MWV_GPIO_IN),
+	regmap_reg_range(BD9571MWV_GPIO_INT, BD9571MWV_GPIO_INT),
+	regmap_reg_range(BD9571MWV_INT_INTREQ, BD9571MWV_INT_INTREQ),
+};
+
+static const struct regmap_access_table bd9571mwv_volatile_table = {
+	.yes_ranges	= bd9571mwv_volatile_yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(bd9571mwv_volatile_yes_ranges),
+};
+
+static const struct regmap_config bd9571mwv_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.cache_type	= REGCACHE_MAPLE,
+	.rd_table	= &bd9571mwv_readable_table,
+	.wr_table	= &bd9571mwv_writable_table,
+	.volatile_table	= &bd9571mwv_volatile_table,
+	.max_register	= 0xff,
+};
+
+static const struct regmap_irq bd9571mwv_irqs[] = {
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_MD1, 0,
+		       BD9571MWV_INT_INTREQ_MD1_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_MD2_E1, 0,
+		       BD9571MWV_INT_INTREQ_MD2_E1_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_MD2_E2, 0,
+		       BD9571MWV_INT_INTREQ_MD2_E2_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_PROT_ERR, 0,
+		       BD9571MWV_INT_INTREQ_PROT_ERR_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_GP, 0,
+		       BD9571MWV_INT_INTREQ_GP_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_128H_OF, 0,
+		       BD9571MWV_INT_INTREQ_128H_OF_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_WDT_OF, 0,
+		       BD9571MWV_INT_INTREQ_WDT_OF_INT),
+	REGMAP_IRQ_REG(BD9571MWV_IRQ_BKUP_TRG, 0,
+		       BD9571MWV_INT_INTREQ_BKUP_TRG_INT),
+};
+
+static const struct regmap_irq_chip bd9571mwv_irq_chip = {
+	.name		= "bd9571mwv",
+	.status_base	= BD9571MWV_INT_INTREQ,
+	.mask_base	= BD9571MWV_INT_INTMASK,
+	.ack_base	= BD9571MWV_INT_INTREQ,
+	.init_ack_masked = true,
+	.num_regs	= 1,
+	.irqs		= bd9571mwv_irqs,
+	.num_irqs	= ARRAY_SIZE(bd9571mwv_irqs),
+};
+
+static const struct mfd_cell bd9574mwf_cells[] = {
+	{ .name = "bd9574mwf-regulator", },
+	{ .name = "bd9574mwf-gpio", },
+};
+
+static const struct regmap_range bd9574mwf_readable_yes_ranges[] = {
+	regmap_reg_range(BD9571MWV_VENDOR_CODE, BD9571MWV_PRODUCT_REVISION),
+	regmap_reg_range(BD9571MWV_BKUP_MODE_CNT, BD9571MWV_BKUP_MODE_CNT),
+	regmap_reg_range(BD9571MWV_DVFS_VINIT, BD9571MWV_DVFS_SETVMAX),
+	regmap_reg_range(BD9571MWV_DVFS_SETVID, BD9571MWV_DVFS_MONIVDAC),
+	regmap_reg_range(BD9571MWV_GPIO_IN, BD9571MWV_GPIO_IN),
+	regmap_reg_range(BD9571MWV_GPIO_INT, BD9571MWV_GPIO_INTMASK),
+	regmap_reg_range(BD9571MWV_INT_INTREQ, BD9571MWV_INT_INTMASK),
+};
+
+static const struct regmap_access_table bd9574mwf_readable_table = {
+	.yes_ranges	= bd9574mwf_readable_yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(bd9574mwf_readable_yes_ranges),
+};
+
+static const struct regmap_range bd9574mwf_writable_yes_ranges[] = {
+	regmap_reg_range(BD9571MWV_BKUP_MODE_CNT, BD9571MWV_BKUP_MODE_CNT),
+	regmap_reg_range(BD9571MWV_DVFS_SETVID, BD9571MWV_DVFS_SETVID),
+	regmap_reg_range(BD9571MWV_GPIO_DIR, BD9571MWV_GPIO_OUT),
+	regmap_reg_range(BD9571MWV_GPIO_INT_SET, BD9571MWV_GPIO_INTMASK),
+	regmap_reg_range(BD9571MWV_INT_INTREQ, BD9571MWV_INT_INTMASK),
+};
+
+static const struct regmap_access_table bd9574mwf_writable_table = {
+	.yes_ranges	= bd9574mwf_writable_yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(bd9574mwf_writable_yes_ranges),
+};
+
+static const struct regmap_range bd9574mwf_volatile_yes_ranges[] = {
+	regmap_reg_range(BD9571MWV_DVFS_MONIVDAC, BD9571MWV_DVFS_MONIVDAC),
+	regmap_reg_range(BD9571MWV_GPIO_IN, BD9571MWV_GPIO_IN),
+	regmap_reg_range(BD9571MWV_GPIO_INT, BD9571MWV_GPIO_INT),
+	regmap_reg_range(BD9571MWV_INT_INTREQ, BD9571MWV_INT_INTREQ),
+};
+
+static const struct regmap_access_table bd9574mwf_volatile_table = {
+	.yes_ranges	= bd9574mwf_volatile_yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(bd9574mwf_volatile_yes_ranges),
+};
+
+static const struct regmap_config bd9574mwf_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.cache_type	= REGCACHE_MAPLE,
+	.rd_table	= &bd9574mwf_readable_table,
+	.wr_table	= &bd9574mwf_writable_table,
+	.volatile_table	= &bd9574mwf_volatile_table,
+	.max_register	= 0xff,
+};
+
+static const struct regmap_irq_chip bd9574mwf_irq_chip = {
+	.name		= "bd9574mwf",
+	.status_base	= BD9571MWV_INT_INTREQ,
+	.mask_base	= BD9571MWV_INT_INTMASK,
+	.ack_base	= BD9571MWV_INT_INTREQ,
+	.init_ack_masked = true,
+	.num_regs	= 1,
+	.irqs		= bd9571mwv_irqs,
+	.num_irqs	= ARRAY_SIZE(bd9571mwv_irqs),
+};
+
+static int bd957x_identify(struct device *dev, struct regmap *regmap)
+{
+	unsigned int value;
+	int ret;
+
+	ret = regmap_read(regmap, BD9571MWV_VENDOR_CODE, &value);
+	if (ret) {
+		dev_err(dev, "Failed to read vendor code register (ret=%i)\n",
+			ret);
+		return ret;
+	}
+
+	if (value != BD9571MWV_VENDOR_CODE_VAL) {
+		dev_err(dev, "Invalid vendor code ID %02x (expected %02x)\n",
+			value, BD9571MWV_VENDOR_CODE_VAL);
+		return -EINVAL;
+	}
+
+	ret = regmap_read(regmap, BD9571MWV_PRODUCT_CODE, &value);
+	if (ret) {
+		dev_err(dev, "Failed to read product code register (ret=%i)\n",
+			ret);
+		return ret;
+	}
+	ret = regmap_read(regmap, BD9571MWV_PRODUCT_REVISION, &value);
+	if (ret) {
+		dev_err(dev, "Failed to read revision register (ret=%i)\n",
+			ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int bd9571mwv_probe(struct i2c_client *client)
+{
+	const struct regmap_config *regmap_config;
+	const struct regmap_irq_chip *irq_chip;
+	const struct mfd_cell *cells;
+	struct device *dev = &client->dev;
+	struct regmap *regmap;
+	struct regmap_irq_chip_data *irq_data;
+	int ret, num_cells, irq = client->irq;
+
+	/* Read the PMIC product code */
+	ret = i2c_smbus_read_byte_data(client, BD9571MWV_PRODUCT_CODE);
+	if (ret < 0) {
+		dev_err(dev, "Failed to read product code\n");
+		return ret;
+	}
+
+	switch (ret) {
+	case BD9571MWV_PRODUCT_CODE_BD9571MWV:
+		regmap_config = &bd9571mwv_regmap_config;
+		irq_chip = &bd9571mwv_irq_chip;
+		cells = bd9571mwv_cells;
+		num_cells = ARRAY_SIZE(bd9571mwv_cells);
+		break;
+	case BD9571MWV_PRODUCT_CODE_BD9574MWF:
+		regmap_config = &bd9574mwf_regmap_config;
+		irq_chip = &bd9574mwf_irq_chip;
+		cells = bd9574mwf_cells;
+		num_cells = ARRAY_SIZE(bd9574mwf_cells);
+		break;
+	default:
+		dev_err(dev, "Unsupported device 0x%x\n", ret);
+		return -ENODEV;
+	}
+
+	regmap = devm_regmap_init_i2c(client, regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(dev, "Failed to initialize register map\n");
+		return PTR_ERR(regmap);
+	}
+
+	ret = bd957x_identify(dev, regmap);
+	if (ret)
+		return ret;
+
+	ret = devm_regmap_add_irq_chip(dev, regmap, irq, IRQF_ONESHOT, 0,
+				       irq_chip, &irq_data);
+	if (ret) {
+		dev_err(dev, "Failed to register IRQ chip\n");
+		return ret;
+	}
+
+	return devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, cells, num_cells,
+				    NULL, 0, regmap_irq_get_domain(irq_data));
+}
+
+static const struct of_device_id bd9571mwv_of_match_table[] = {
+	{ .compatible = "rohm,bd9571mwv", },
+	{ .compatible = "rohm,bd9574mwf", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, bd9571mwv_of_match_table);
+
+static const struct i2c_device_id bd9571mwv_id_table[] = {
+	{ "bd9571mwv" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, bd9571mwv_id_table);
+
+static struct i2c_driver bd9571mwv_driver = {
+	.driver		= {
+		.name	= "bd9571mwv",
+		.of_match_table = bd9571mwv_of_match_table,
+	},
+	.probe		= bd9571mwv_probe,
+	.id_table       = bd9571mwv_id_table,
+};
+module_i2c_driver(bd9571mwv_driver);
+
+MODULE_AUTHOR("Marek Vasut <marek.vasut+renesas@gmail.com>");
+MODULE_DESCRIPTION("BD9571MWV PMIC Driver");
+MODULE_LICENSE("GPL v2");