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, 232 insertions, 0 deletions

diff --git a/drivers/reset/reset-ma35d1.c b/drivers/reset/reset-ma35d1.c
new file mode 100644
index 000000000..4ee901f00
--- /dev/null
+++ b/drivers/reset/reset-ma35d1.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 Nuvoton Technology Corp.
+ * Author: Chi-Fang Li <cfli0@nuvoton.com>
+ */
+
+#include <linux/bits.h>
+#include <linux/container_of.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/reset-controller.h>
+#include <linux/spinlock.h>
+#include <dt-bindings/reset/nuvoton,ma35d1-reset.h>
+
+struct ma35d1_reset_data {
+	struct reset_controller_dev rcdev;
+	void __iomem *base;
+	/* protect registers against concurrent read-modify-write */
+	spinlock_t lock;
+};
+
+static const struct {
+	u32 reg_ofs;
+	u32 bit;
+} ma35d1_reset_map[] = {
+	[MA35D1_RESET_CHIP] =    {0x20, 0},
+	[MA35D1_RESET_CA35CR0] = {0x20, 1},
+	[MA35D1_RESET_CA35CR1] = {0x20, 2},
+	[MA35D1_RESET_CM4] =     {0x20, 3},
+	[MA35D1_RESET_PDMA0] =   {0x20, 4},
+	[MA35D1_RESET_PDMA1] =   {0x20, 5},
+	[MA35D1_RESET_PDMA2] =   {0x20, 6},
+	[MA35D1_RESET_PDMA3] =   {0x20, 7},
+	[MA35D1_RESET_DISP] =    {0x20, 9},
+	[MA35D1_RESET_VCAP0] =   {0x20, 10},
+	[MA35D1_RESET_VCAP1] =   {0x20, 11},
+	[MA35D1_RESET_GFX] =     {0x20, 12},
+	[MA35D1_RESET_VDEC] =    {0x20, 13},
+	[MA35D1_RESET_WHC0] =    {0x20, 14},
+	[MA35D1_RESET_WHC1] =    {0x20, 15},
+	[MA35D1_RESET_GMAC0] =   {0x20, 16},
+	[MA35D1_RESET_GMAC1] =   {0x20, 17},
+	[MA35D1_RESET_HWSEM] =   {0x20, 18},
+	[MA35D1_RESET_EBI] =     {0x20, 19},
+	[MA35D1_RESET_HSUSBH0] = {0x20, 20},
+	[MA35D1_RESET_HSUSBH1] = {0x20, 21},
+	[MA35D1_RESET_HSUSBD] =  {0x20, 22},
+	[MA35D1_RESET_USBHL] =   {0x20, 23},
+	[MA35D1_RESET_SDH0] =    {0x20, 24},
+	[MA35D1_RESET_SDH1] =    {0x20, 25},
+	[MA35D1_RESET_NAND] =    {0x20, 26},
+	[MA35D1_RESET_GPIO] =    {0x20, 27},
+	[MA35D1_RESET_MCTLP] =   {0x20, 28},
+	[MA35D1_RESET_MCTLC] =   {0x20, 29},
+	[MA35D1_RESET_DDRPUB] =  {0x20, 30},
+	[MA35D1_RESET_TMR0] =    {0x24, 2},
+	[MA35D1_RESET_TMR1] =    {0x24, 3},
+	[MA35D1_RESET_TMR2] =    {0x24, 4},
+	[MA35D1_RESET_TMR3] =    {0x24, 5},
+	[MA35D1_RESET_I2C0] =    {0x24, 8},
+	[MA35D1_RESET_I2C1] =    {0x24, 9},
+	[MA35D1_RESET_I2C2] =    {0x24, 10},
+	[MA35D1_RESET_I2C3] =    {0x24, 11},
+	[MA35D1_RESET_QSPI0] =   {0x24, 12},
+	[MA35D1_RESET_SPI0] =    {0x24, 13},
+	[MA35D1_RESET_SPI1] =    {0x24, 14},
+	[MA35D1_RESET_SPI2] =    {0x24, 15},
+	[MA35D1_RESET_UART0] =   {0x24, 16},
+	[MA35D1_RESET_UART1] =   {0x24, 17},
+	[MA35D1_RESET_UART2] =   {0x24, 18},
+	[MA35D1_RESET_UART3] =   {0x24, 19},
+	[MA35D1_RESET_UART4] =   {0x24, 20},
+	[MA35D1_RESET_UART5] =   {0x24, 21},
+	[MA35D1_RESET_UART6] =   {0x24, 22},
+	[MA35D1_RESET_UART7] =   {0x24, 23},
+	[MA35D1_RESET_CANFD0] =  {0x24, 24},
+	[MA35D1_RESET_CANFD1] =  {0x24, 25},
+	[MA35D1_RESET_EADC0] =   {0x24, 28},
+	[MA35D1_RESET_I2S0] =    {0x24, 29},
+	[MA35D1_RESET_SC0] =     {0x28, 0},
+	[MA35D1_RESET_SC1] =     {0x28, 1},
+	[MA35D1_RESET_QSPI1] =   {0x28, 4},
+	[MA35D1_RESET_SPI3] =    {0x28, 6},
+	[MA35D1_RESET_EPWM0] =   {0x28, 16},
+	[MA35D1_RESET_EPWM1] =   {0x28, 17},
+	[MA35D1_RESET_QEI0] =    {0x28, 22},
+	[MA35D1_RESET_QEI1] =    {0x28, 23},
+	[MA35D1_RESET_ECAP0] =   {0x28, 26},
+	[MA35D1_RESET_ECAP1] =   {0x28, 27},
+	[MA35D1_RESET_CANFD2] =  {0x28, 28},
+	[MA35D1_RESET_ADC0] =    {0x28, 31},
+	[MA35D1_RESET_TMR4] =    {0x2C, 0},
+	[MA35D1_RESET_TMR5] =    {0x2C, 1},
+	[MA35D1_RESET_TMR6] =    {0x2C, 2},
+	[MA35D1_RESET_TMR7] =    {0x2C, 3},
+	[MA35D1_RESET_TMR8] =    {0x2C, 4},
+	[MA35D1_RESET_TMR9] =    {0x2C, 5},
+	[MA35D1_RESET_TMR10] =   {0x2C, 6},
+	[MA35D1_RESET_TMR11] =   {0x2C, 7},
+	[MA35D1_RESET_UART8] =   {0x2C, 8},
+	[MA35D1_RESET_UART9] =   {0x2C, 9},
+	[MA35D1_RESET_UART10] =  {0x2C, 10},
+	[MA35D1_RESET_UART11] =  {0x2C, 11},
+	[MA35D1_RESET_UART12] =  {0x2C, 12},
+	[MA35D1_RESET_UART13] =  {0x2C, 13},
+	[MA35D1_RESET_UART14] =  {0x2C, 14},
+	[MA35D1_RESET_UART15] =  {0x2C, 15},
+	[MA35D1_RESET_UART16] =  {0x2C, 16},
+	[MA35D1_RESET_I2S1] =    {0x2C, 17},
+	[MA35D1_RESET_I2C4] =    {0x2C, 18},
+	[MA35D1_RESET_I2C5] =    {0x2C, 19},
+	[MA35D1_RESET_EPWM2] =   {0x2C, 20},
+	[MA35D1_RESET_ECAP2] =   {0x2C, 21},
+	[MA35D1_RESET_QEI2] =    {0x2C, 22},
+	[MA35D1_RESET_CANFD3] =  {0x2C, 23},
+	[MA35D1_RESET_KPI] =     {0x2C, 24},
+	[MA35D1_RESET_GIC] =     {0x2C, 28},
+	[MA35D1_RESET_SSMCC] =   {0x2C, 30},
+	[MA35D1_RESET_SSPCC] =   {0x2C, 31}
+};
+
+static int ma35d1_restart_handler(struct sys_off_data *sys_off_data)
+{
+	struct ma35d1_reset_data *data = sys_off_data->cb_data;
+	u32 id = MA35D1_RESET_CHIP;
+
+	writel_relaxed(BIT(ma35d1_reset_map[id].bit),
+		       data->base + ma35d1_reset_map[id].reg_ofs);
+	return 0;
+}
+
+static int ma35d1_reset_update(struct reset_controller_dev *rcdev, unsigned long id, bool assert)
+{
+	struct ma35d1_reset_data *data = container_of(rcdev, struct ma35d1_reset_data, rcdev);
+	unsigned long flags;
+	u32 reg;
+
+	if (WARN_ON_ONCE(id >= ARRAY_SIZE(ma35d1_reset_map)))
+		return -EINVAL;
+
+	spin_lock_irqsave(&data->lock, flags);
+	reg = readl_relaxed(data->base + ma35d1_reset_map[id].reg_ofs);
+	if (assert)
+		reg |= BIT(ma35d1_reset_map[id].bit);
+	else
+		reg &= ~(BIT(ma35d1_reset_map[id].bit));
+	writel_relaxed(reg, data->base + ma35d1_reset_map[id].reg_ofs);
+	spin_unlock_irqrestore(&data->lock, flags);
+
+	return 0;
+}
+
+static int ma35d1_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	return ma35d1_reset_update(rcdev, id, true);
+}
+
+static int ma35d1_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	return ma35d1_reset_update(rcdev, id, false);
+}
+
+static int ma35d1_reset_status(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	struct ma35d1_reset_data *data = container_of(rcdev, struct ma35d1_reset_data, rcdev);
+	u32 reg;
+
+	if (WARN_ON_ONCE(id >= ARRAY_SIZE(ma35d1_reset_map)))
+		return -EINVAL;
+
+	reg = readl_relaxed(data->base + ma35d1_reset_map[id].reg_ofs);
+	return !!(reg & BIT(ma35d1_reset_map[id].bit));
+}
+
+static const struct reset_control_ops ma35d1_reset_ops = {
+	.assert = ma35d1_reset_assert,
+	.deassert = ma35d1_reset_deassert,
+	.status = ma35d1_reset_status,
+};
+
+static const struct of_device_id ma35d1_reset_dt_ids[] = {
+	{ .compatible = "nuvoton,ma35d1-reset" },
+	{ },
+};
+
+static int ma35d1_reset_probe(struct platform_device *pdev)
+{
+	struct ma35d1_reset_data *reset_data;
+	struct device *dev = &pdev->dev;
+	int err;
+
+	if (!pdev->dev.of_node) {
+		dev_err(&pdev->dev, "Device tree node not found\n");
+		return -EINVAL;
+	}
+
+	reset_data = devm_kzalloc(dev, sizeof(*reset_data), GFP_KERNEL);
+	if (!reset_data)
+		return -ENOMEM;
+
+	reset_data->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(reset_data->base))
+		return PTR_ERR(reset_data->base);
+
+	reset_data->rcdev.owner = THIS_MODULE;
+	reset_data->rcdev.nr_resets = MA35D1_RESET_COUNT;
+	reset_data->rcdev.ops = &ma35d1_reset_ops;
+	reset_data->rcdev.of_node = dev->of_node;
+	spin_lock_init(&reset_data->lock);
+
+	err = devm_register_sys_off_handler(dev, SYS_OFF_MODE_RESTART, 192,
+					    ma35d1_restart_handler, reset_data);
+	if (err)
+		dev_warn(&pdev->dev, "failed to register restart handler\n");
+
+	return devm_reset_controller_register(dev, &reset_data->rcdev);
+}
+
+static struct platform_driver ma35d1_reset_driver = {
+	.probe = ma35d1_reset_probe,
+	.driver = {
+		.name = "ma35d1-reset",
+		.of_match_table	= ma35d1_reset_dt_ids,
+	},
+};
+
+builtin_platform_driver(ma35d1_reset_driver);