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>

4 files changed, 519 insertions, 0 deletions

diff --git a/drivers/soc/pxa/Kconfig b/drivers/soc/pxa/Kconfig
new file mode 100644
index 000000000..c5c265aa4
--- /dev/null
+++ b/drivers/soc/pxa/Kconfig
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config PLAT_PXA
+	bool
+
+config PXA_SSP
+	tristate
+	help
+	  Enable support for PXA2xx SSP ports
diff --git a/drivers/soc/pxa/Makefile b/drivers/soc/pxa/Makefile
new file mode 100644
index 000000000..413decedd
--- /dev/null
+++ b/drivers/soc/pxa/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_PXA3xx)		+= mfp.o
+obj-$(CONFIG_ARCH_MMP)		+= mfp.o
+
+obj-$(CONFIG_PXA_SSP)		+= ssp.o
diff --git a/drivers/soc/pxa/mfp.c b/drivers/soc/pxa/mfp.c
new file mode 100644
index 000000000..6220ba321
--- /dev/null
+++ b/drivers/soc/pxa/mfp.c
@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/arch/arm/plat-pxa/mfp.c
+ *
+ *   Multi-Function Pin Support
+ *
+ * Copyright (C) 2007 Marvell Internation Ltd.
+ *
+ * 2007-08-21: eric miao <eric.miao@marvell.com>
+ *             initial version
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+
+#include <linux/soc/pxa/mfp.h>
+
+#define MFPR_SIZE	(PAGE_SIZE)
+
+/* MFPR register bit definitions */
+#define MFPR_PULL_SEL		(0x1 << 15)
+#define MFPR_PULLUP_EN		(0x1 << 14)
+#define MFPR_PULLDOWN_EN	(0x1 << 13)
+#define MFPR_SLEEP_SEL		(0x1 << 9)
+#define MFPR_SLEEP_OE_N		(0x1 << 7)
+#define MFPR_EDGE_CLEAR		(0x1 << 6)
+#define MFPR_EDGE_FALL_EN	(0x1 << 5)
+#define MFPR_EDGE_RISE_EN	(0x1 << 4)
+
+#define MFPR_SLEEP_DATA(x)	((x) << 8)
+#define MFPR_DRIVE(x)		(((x) & 0x7) << 10)
+#define MFPR_AF_SEL(x)		(((x) & 0x7) << 0)
+
+#define MFPR_EDGE_NONE		(0)
+#define MFPR_EDGE_RISE		(MFPR_EDGE_RISE_EN)
+#define MFPR_EDGE_FALL		(MFPR_EDGE_FALL_EN)
+#define MFPR_EDGE_BOTH		(MFPR_EDGE_RISE | MFPR_EDGE_FALL)
+
+/*
+ * Table that determines the low power modes outputs, with actual settings
+ * used in parentheses for don't-care values. Except for the float output,
+ * the configured driven and pulled levels match, so if there is a need for
+ * non-LPM pulled output, the same configuration could probably be used.
+ *
+ * Output value  sleep_oe_n  sleep_data  pullup_en  pulldown_en  pull_sel
+ *                 (bit 7)    (bit 8)    (bit 14)     (bit 13)   (bit 15)
+ *
+ * Input            0          X(0)        X(0)        X(0)       0
+ * Drive 0          0          0           0           X(1)       0
+ * Drive 1          0          1           X(1)        0	  0
+ * Pull hi (1)      1          X(1)        1           0	  0
+ * Pull lo (0)      1          X(0)        0           1	  0
+ * Z (float)        1          X(0)        0           0	  0
+ */
+#define MFPR_LPM_INPUT		(0)
+#define MFPR_LPM_DRIVE_LOW	(MFPR_SLEEP_DATA(0) | MFPR_PULLDOWN_EN)
+#define MFPR_LPM_DRIVE_HIGH    	(MFPR_SLEEP_DATA(1) | MFPR_PULLUP_EN)
+#define MFPR_LPM_PULL_LOW      	(MFPR_LPM_DRIVE_LOW  | MFPR_SLEEP_OE_N)
+#define MFPR_LPM_PULL_HIGH     	(MFPR_LPM_DRIVE_HIGH | MFPR_SLEEP_OE_N)
+#define MFPR_LPM_FLOAT         	(MFPR_SLEEP_OE_N)
+#define MFPR_LPM_MASK		(0xe080)
+
+/*
+ * The pullup and pulldown state of the MFP pin at run mode is by default
+ * determined by the selected alternate function. In case that some buggy
+ * devices need to override this default behavior,  the definitions below
+ * indicates the setting of corresponding MFPR bits
+ *
+ * Definition       pull_sel  pullup_en  pulldown_en
+ * MFPR_PULL_NONE       0         0        0
+ * MFPR_PULL_LOW        1         0        1
+ * MFPR_PULL_HIGH       1         1        0
+ * MFPR_PULL_BOTH       1         1        1
+ * MFPR_PULL_FLOAT	1         0        0
+ */
+#define MFPR_PULL_NONE		(0)
+#define MFPR_PULL_LOW		(MFPR_PULL_SEL | MFPR_PULLDOWN_EN)
+#define MFPR_PULL_BOTH		(MFPR_PULL_LOW | MFPR_PULLUP_EN)
+#define MFPR_PULL_HIGH		(MFPR_PULL_SEL | MFPR_PULLUP_EN)
+#define MFPR_PULL_FLOAT		(MFPR_PULL_SEL)
+
+/* mfp_spin_lock is used to ensure that MFP register configuration
+ * (most likely a read-modify-write operation) is atomic, and that
+ * mfp_table[] is consistent
+ */
+static DEFINE_SPINLOCK(mfp_spin_lock);
+
+static void __iomem *mfpr_mmio_base;
+
+struct mfp_pin {
+	unsigned long	config;		/* -1 for not configured */
+	unsigned long	mfpr_off;	/* MFPRxx Register offset */
+	unsigned long	mfpr_run;	/* Run-Mode Register Value */
+	unsigned long	mfpr_lpm;	/* Low Power Mode Register Value */
+};
+
+static struct mfp_pin mfp_table[MFP_PIN_MAX];
+
+/* mapping of MFP_LPM_* definitions to MFPR_LPM_* register bits */
+static const unsigned long mfpr_lpm[] = {
+	MFPR_LPM_INPUT,
+	MFPR_LPM_DRIVE_LOW,
+	MFPR_LPM_DRIVE_HIGH,
+	MFPR_LPM_PULL_LOW,
+	MFPR_LPM_PULL_HIGH,
+	MFPR_LPM_FLOAT,
+	MFPR_LPM_INPUT,
+};
+
+/* mapping of MFP_PULL_* definitions to MFPR_PULL_* register bits */
+static const unsigned long mfpr_pull[] = {
+	MFPR_PULL_NONE,
+	MFPR_PULL_LOW,
+	MFPR_PULL_HIGH,
+	MFPR_PULL_BOTH,
+	MFPR_PULL_FLOAT,
+};
+
+/* mapping of MFP_LPM_EDGE_* definitions to MFPR_EDGE_* register bits */
+static const unsigned long mfpr_edge[] = {
+	MFPR_EDGE_NONE,
+	MFPR_EDGE_RISE,
+	MFPR_EDGE_FALL,
+	MFPR_EDGE_BOTH,
+};
+
+#define mfpr_readl(off)			\
+	__raw_readl(mfpr_mmio_base + (off))
+
+#define mfpr_writel(off, val)		\
+	__raw_writel(val, mfpr_mmio_base + (off))
+
+#define mfp_configured(p)	((p)->config != -1)
+
+/*
+ * perform a read-back of any valid MFPR register to make sure the
+ * previous writings are finished
+ */
+static unsigned long mfpr_off_readback;
+#define mfpr_sync()	(void)__raw_readl(mfpr_mmio_base + mfpr_off_readback)
+
+static inline void __mfp_config_run(struct mfp_pin *p)
+{
+	if (mfp_configured(p))
+		mfpr_writel(p->mfpr_off, p->mfpr_run);
+}
+
+static inline void __mfp_config_lpm(struct mfp_pin *p)
+{
+	if (mfp_configured(p)) {
+		unsigned long mfpr_clr = (p->mfpr_run & ~MFPR_EDGE_BOTH) | MFPR_EDGE_CLEAR;
+		if (mfpr_clr != p->mfpr_run)
+			mfpr_writel(p->mfpr_off, mfpr_clr);
+		if (p->mfpr_lpm != mfpr_clr)
+			mfpr_writel(p->mfpr_off, p->mfpr_lpm);
+	}
+}
+
+void mfp_config(unsigned long *mfp_cfgs, int num)
+{
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&mfp_spin_lock, flags);
+
+	for (i = 0; i < num; i++, mfp_cfgs++) {
+		unsigned long tmp, c = *mfp_cfgs;
+		struct mfp_pin *p;
+		int pin, af, drv, lpm, edge, pull;
+
+		pin = MFP_PIN(c);
+		BUG_ON(pin >= MFP_PIN_MAX);
+		p = &mfp_table[pin];
+
+		af  = MFP_AF(c);
+		drv = MFP_DS(c);
+		lpm = MFP_LPM_STATE(c);
+		edge = MFP_LPM_EDGE(c);
+		pull = MFP_PULL(c);
+
+		/* run-mode pull settings will conflict with MFPR bits of
+		 * low power mode state,  calculate mfpr_run and mfpr_lpm
+		 * individually if pull != MFP_PULL_NONE
+		 */
+		tmp = MFPR_AF_SEL(af) | MFPR_DRIVE(drv);
+
+		if (likely(pull == MFP_PULL_NONE)) {
+			p->mfpr_run = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
+			p->mfpr_lpm = p->mfpr_run;
+		} else {
+			p->mfpr_lpm = tmp | mfpr_lpm[lpm] | mfpr_edge[edge];
+			p->mfpr_run = tmp | mfpr_pull[pull];
+		}
+
+		p->config = c; __mfp_config_run(p);
+	}
+
+	mfpr_sync();
+	spin_unlock_irqrestore(&mfp_spin_lock, flags);
+}
+
+unsigned long mfp_read(int mfp)
+{
+	unsigned long val, flags;
+
+	BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX);
+
+	spin_lock_irqsave(&mfp_spin_lock, flags);
+	val = mfpr_readl(mfp_table[mfp].mfpr_off);
+	spin_unlock_irqrestore(&mfp_spin_lock, flags);
+
+	return val;
+}
+
+void mfp_write(int mfp, unsigned long val)
+{
+	unsigned long flags;
+
+	BUG_ON(mfp < 0 || mfp >= MFP_PIN_MAX);
+
+	spin_lock_irqsave(&mfp_spin_lock, flags);
+	mfpr_writel(mfp_table[mfp].mfpr_off, val);
+	mfpr_sync();
+	spin_unlock_irqrestore(&mfp_spin_lock, flags);
+}
+
+void __init mfp_init_base(void __iomem *mfpr_base)
+{
+	int i;
+
+	/* initialize the table with default - unconfigured */
+	for (i = 0; i < ARRAY_SIZE(mfp_table); i++)
+		mfp_table[i].config = -1;
+
+	mfpr_mmio_base = mfpr_base;
+}
+
+void __init mfp_init_addr(struct mfp_addr_map *map)
+{
+	struct mfp_addr_map *p;
+	unsigned long offset, flags;
+	int i;
+
+	spin_lock_irqsave(&mfp_spin_lock, flags);
+
+	/* mfp offset for readback */
+	mfpr_off_readback = map[0].offset;
+
+	for (p = map; p->start != MFP_PIN_INVALID; p++) {
+		offset = p->offset;
+		i = p->start;
+
+		do {
+			mfp_table[i].mfpr_off = offset;
+			mfp_table[i].mfpr_run = 0;
+			mfp_table[i].mfpr_lpm = 0;
+			offset += 4; i++;
+		} while ((i <= p->end) && (p->end != -1));
+	}
+
+	spin_unlock_irqrestore(&mfp_spin_lock, flags);
+}
+
+void mfp_config_lpm(void)
+{
+	struct mfp_pin *p = &mfp_table[0];
+	int pin;
+
+	for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++, p++)
+		__mfp_config_lpm(p);
+}
+
+void mfp_config_run(void)
+{
+	struct mfp_pin *p = &mfp_table[0];
+	int pin;
+
+	for (pin = 0; pin < ARRAY_SIZE(mfp_table); pin++, p++)
+		__mfp_config_run(p);
+}
diff --git a/drivers/soc/pxa/ssp.c b/drivers/soc/pxa/ssp.c
new file mode 100644
index 000000000..bb0062c16
--- /dev/null
+++ b/drivers/soc/pxa/ssp.c
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/arch/arm/mach-pxa/ssp.c
+ *
+ *  based on linux/arch/arm/mach-sa1100/ssp.c by Russell King
+ *
+ *  Copyright (C) 2003 Russell King.
+ *  Copyright (C) 2003 Wolfson Microelectronics PLC
+ *
+ *  PXA2xx SSP driver.  This provides the generic core for simple
+ *  IO-based SSP applications and allows easy port setup for DMA access.
+ *
+ *  Author: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/pxa2xx_ssp.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include <asm/irq.h>
+
+static DEFINE_MUTEX(ssp_lock);
+static LIST_HEAD(ssp_list);
+
+struct ssp_device *pxa_ssp_request(int port, const char *label)
+{
+	struct ssp_device *ssp = NULL;
+
+	mutex_lock(&ssp_lock);
+
+	list_for_each_entry(ssp, &ssp_list, node) {
+		if (ssp->port_id == port && ssp->use_count == 0) {
+			ssp->use_count++;
+			ssp->label = label;
+			break;
+		}
+	}
+
+	mutex_unlock(&ssp_lock);
+
+	if (&ssp->node == &ssp_list)
+		return NULL;
+
+	return ssp;
+}
+EXPORT_SYMBOL(pxa_ssp_request);
+
+struct ssp_device *pxa_ssp_request_of(const struct device_node *of_node,
+				      const char *label)
+{
+	struct ssp_device *ssp = NULL;
+
+	mutex_lock(&ssp_lock);
+
+	list_for_each_entry(ssp, &ssp_list, node) {
+		if (ssp->of_node == of_node && ssp->use_count == 0) {
+			ssp->use_count++;
+			ssp->label = label;
+			break;
+		}
+	}
+
+	mutex_unlock(&ssp_lock);
+
+	if (&ssp->node == &ssp_list)
+		return NULL;
+
+	return ssp;
+}
+EXPORT_SYMBOL(pxa_ssp_request_of);
+
+void pxa_ssp_free(struct ssp_device *ssp)
+{
+	mutex_lock(&ssp_lock);
+	if (ssp->use_count) {
+		ssp->use_count--;
+		ssp->label = NULL;
+	} else
+		dev_err(ssp->dev, "device already free\n");
+	mutex_unlock(&ssp_lock);
+}
+EXPORT_SYMBOL(pxa_ssp_free);
+
+#ifdef CONFIG_OF
+static const struct of_device_id pxa_ssp_of_ids[] = {
+	{ .compatible = "mrvl,pxa25x-ssp",	.data = (void *) PXA25x_SSP },
+	{ .compatible = "mvrl,pxa25x-nssp",	.data = (void *) PXA25x_NSSP },
+	{ .compatible = "mrvl,pxa27x-ssp",	.data = (void *) PXA27x_SSP },
+	{ .compatible = "mrvl,pxa3xx-ssp",	.data = (void *) PXA3xx_SSP },
+	{ .compatible = "mvrl,pxa168-ssp",	.data = (void *) PXA168_SSP },
+	{ .compatible = "mrvl,pxa910-ssp",	.data = (void *) PXA910_SSP },
+	{ .compatible = "mrvl,ce4100-ssp",	.data = (void *) CE4100_SSP },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, pxa_ssp_of_ids);
+#endif
+
+static int pxa_ssp_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct ssp_device *ssp;
+	struct device *dev = &pdev->dev;
+
+	ssp = devm_kzalloc(dev, sizeof(struct ssp_device), GFP_KERNEL);
+	if (ssp == NULL)
+		return -ENOMEM;
+
+	ssp->dev = dev;
+
+	ssp->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(ssp->clk))
+		return PTR_ERR(ssp->clk);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res == NULL) {
+		dev_err(dev, "no memory resource defined\n");
+		return -ENODEV;
+	}
+
+	res = devm_request_mem_region(dev, res->start, resource_size(res),
+				      pdev->name);
+	if (res == NULL) {
+		dev_err(dev, "failed to request memory resource\n");
+		return -EBUSY;
+	}
+
+	ssp->phys_base = res->start;
+
+	ssp->mmio_base = devm_ioremap(dev, res->start, resource_size(res));
+	if (ssp->mmio_base == NULL) {
+		dev_err(dev, "failed to ioremap() registers\n");
+		return -ENODEV;
+	}
+
+	ssp->irq = platform_get_irq(pdev, 0);
+	if (ssp->irq < 0)
+		return -ENODEV;
+
+	if (dev->of_node) {
+		const struct of_device_id *id =
+			of_match_device(of_match_ptr(pxa_ssp_of_ids), dev);
+		ssp->type = (uintptr_t) id->data;
+	} else {
+		const struct platform_device_id *id =
+			platform_get_device_id(pdev);
+		ssp->type = id->driver_data;
+
+		/* PXA2xx/3xx SSP ports starts from 1 and the internal pdev->id
+		 * starts from 0, do a translation here
+		 */
+		ssp->port_id = pdev->id + 1;
+	}
+
+	ssp->use_count = 0;
+	ssp->of_node = dev->of_node;
+
+	mutex_lock(&ssp_lock);
+	list_add(&ssp->node, &ssp_list);
+	mutex_unlock(&ssp_lock);
+
+	platform_set_drvdata(pdev, ssp);
+
+	return 0;
+}
+
+static void pxa_ssp_remove(struct platform_device *pdev)
+{
+	struct ssp_device *ssp = platform_get_drvdata(pdev);
+
+	mutex_lock(&ssp_lock);
+	list_del(&ssp->node);
+	mutex_unlock(&ssp_lock);
+}
+
+static const struct platform_device_id ssp_id_table[] = {
+	{ "pxa25x-ssp",		PXA25x_SSP },
+	{ "pxa25x-nssp",	PXA25x_NSSP },
+	{ "pxa27x-ssp",		PXA27x_SSP },
+	{ "pxa3xx-ssp",		PXA3xx_SSP },
+	{ "pxa168-ssp",		PXA168_SSP },
+	{ "pxa910-ssp",		PXA910_SSP },
+	{ },
+};
+
+static struct platform_driver pxa_ssp_driver = {
+	.probe		= pxa_ssp_probe,
+	.remove		= pxa_ssp_remove,
+	.driver		= {
+		.name		= "pxa2xx-ssp",
+		.of_match_table	= of_match_ptr(pxa_ssp_of_ids),
+	},
+	.id_table	= ssp_id_table,
+};
+
+static int __init pxa_ssp_init(void)
+{
+	return platform_driver_register(&pxa_ssp_driver);
+}
+
+static void __exit pxa_ssp_exit(void)
+{
+	platform_driver_unregister(&pxa_ssp_driver);
+}
+
+arch_initcall(pxa_ssp_init);
+module_exit(pxa_ssp_exit);
+
+MODULE_DESCRIPTION("PXA SSP driver");
+MODULE_AUTHOR("Liam Girdwood");
+MODULE_LICENSE("GPL");