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, 429 insertions, 0 deletions

diff --git a/drivers/pnp/manager.c b/drivers/pnp/manager.c
new file mode 100644
index 000000000..1765d6e60
--- /dev/null
+++ b/drivers/pnp/manager.c
@@ -0,0 +1,429 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * manager.c - Resource Management, Conflict Resolution, Activation and Disabling of Devices
+ *
+ * based on isapnp.c resource management (c) Jaroslav Kysela <perex@perex.cz>
+ * Copyright 2003 Adam Belay <ambx1@neo.rr.com>
+ * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
+ *	Bjorn Helgaas <bjorn.helgaas@hp.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/pnp.h>
+#include <linux/bitmap.h>
+#include <linux/mutex.h>
+#include "base.h"
+
+DEFINE_MUTEX(pnp_res_mutex);
+
+static struct resource *pnp_find_resource(struct pnp_dev *dev,
+					  unsigned char rule,
+					  unsigned long type,
+					  unsigned int bar)
+{
+	struct resource *res = pnp_get_resource(dev, type, bar);
+
+	/* when the resource already exists, set its resource bits from rule */
+	if (res) {
+		res->flags &= ~IORESOURCE_BITS;
+		res->flags |= rule & IORESOURCE_BITS;
+	}
+
+	return res;
+}
+
+static int pnp_assign_port(struct pnp_dev *dev, struct pnp_port *rule, int idx)
+{
+	struct resource *res, local_res;
+
+	res = pnp_find_resource(dev, rule->flags, IORESOURCE_IO, idx);
+	if (res) {
+		pnp_dbg(&dev->dev, "  io %d already set to %#llx-%#llx "
+			"flags %#lx\n", idx, (unsigned long long) res->start,
+			(unsigned long long) res->end, res->flags);
+		return 0;
+	}
+
+	res = &local_res;
+	res->flags = rule->flags | IORESOURCE_AUTO;
+	res->start = 0;
+	res->end = 0;
+
+	if (!rule->size) {
+		res->flags |= IORESOURCE_DISABLED;
+		pnp_dbg(&dev->dev, "  io %d disabled\n", idx);
+		goto __add;
+	}
+
+	res->start = rule->min;
+	res->end = res->start + rule->size - 1;
+
+	while (!pnp_check_port(dev, res)) {
+		res->start += rule->align;
+		res->end = res->start + rule->size - 1;
+		if (res->start > rule->max || !rule->align) {
+			pnp_dbg(&dev->dev, "  couldn't assign io %d "
+				"(min %#llx max %#llx)\n", idx,
+				(unsigned long long) rule->min,
+				(unsigned long long) rule->max);
+			return -EBUSY;
+		}
+	}
+
+__add:
+	pnp_add_io_resource(dev, res->start, res->end, res->flags);
+	return 0;
+}
+
+static int pnp_assign_mem(struct pnp_dev *dev, struct pnp_mem *rule, int idx)
+{
+	struct resource *res, local_res;
+
+	res = pnp_find_resource(dev, rule->flags, IORESOURCE_MEM, idx);
+	if (res) {
+		pnp_dbg(&dev->dev, "  mem %d already set to %#llx-%#llx "
+			"flags %#lx\n", idx, (unsigned long long) res->start,
+			(unsigned long long) res->end, res->flags);
+		return 0;
+	}
+
+	res = &local_res;
+	res->flags = rule->flags | IORESOURCE_AUTO;
+	res->start = 0;
+	res->end = 0;
+
+	/* ??? rule->flags restricted to 8 bits, all tests bogus ??? */
+	if (!(rule->flags & IORESOURCE_MEM_WRITEABLE))
+		res->flags |= IORESOURCE_READONLY;
+	if (rule->flags & IORESOURCE_MEM_RANGELENGTH)
+		res->flags |= IORESOURCE_RANGELENGTH;
+	if (rule->flags & IORESOURCE_MEM_SHADOWABLE)
+		res->flags |= IORESOURCE_SHADOWABLE;
+
+	if (!rule->size) {
+		res->flags |= IORESOURCE_DISABLED;
+		pnp_dbg(&dev->dev, "  mem %d disabled\n", idx);
+		goto __add;
+	}
+
+	res->start = rule->min;
+	res->end = res->start + rule->size - 1;
+
+	while (!pnp_check_mem(dev, res)) {
+		res->start += rule->align;
+		res->end = res->start + rule->size - 1;
+		if (res->start > rule->max || !rule->align) {
+			pnp_dbg(&dev->dev, "  couldn't assign mem %d "
+				"(min %#llx max %#llx)\n", idx,
+				(unsigned long long) rule->min,
+				(unsigned long long) rule->max);
+			return -EBUSY;
+		}
+	}
+
+__add:
+	pnp_add_mem_resource(dev, res->start, res->end, res->flags);
+	return 0;
+}
+
+static int pnp_assign_irq(struct pnp_dev *dev, struct pnp_irq *rule, int idx)
+{
+	struct resource *res, local_res;
+	int i;
+
+	/* IRQ priority: this table is good for i386 */
+	static unsigned short xtab[16] = {
+		5, 10, 11, 12, 9, 14, 15, 7, 3, 4, 13, 0, 1, 6, 8, 2
+	};
+
+	res = pnp_find_resource(dev, rule->flags, IORESOURCE_IRQ, idx);
+	if (res) {
+		pnp_dbg(&dev->dev, "  irq %d already set to %d flags %#lx\n",
+			idx, (int) res->start, res->flags);
+		return 0;
+	}
+
+	res = &local_res;
+	res->flags = rule->flags | IORESOURCE_AUTO;
+	res->start = -1;
+	res->end = -1;
+
+	if (bitmap_empty(rule->map.bits, PNP_IRQ_NR)) {
+		res->flags |= IORESOURCE_DISABLED;
+		pnp_dbg(&dev->dev, "  irq %d disabled\n", idx);
+		goto __add;
+	}
+
+	/* TBD: need check for >16 IRQ */
+	res->start = find_next_bit(rule->map.bits, PNP_IRQ_NR, 16);
+	if (res->start < PNP_IRQ_NR) {
+		res->end = res->start;
+		goto __add;
+	}
+	for (i = 0; i < 16; i++) {
+		if (test_bit(xtab[i], rule->map.bits)) {
+			res->start = res->end = xtab[i];
+			if (pnp_check_irq(dev, res))
+				goto __add;
+		}
+	}
+
+	if (rule->flags & IORESOURCE_IRQ_OPTIONAL) {
+		res->start = -1;
+		res->end = -1;
+		res->flags |= IORESOURCE_DISABLED;
+		pnp_dbg(&dev->dev, "  irq %d disabled (optional)\n", idx);
+		goto __add;
+	}
+
+	pnp_dbg(&dev->dev, "  couldn't assign irq %d\n", idx);
+	return -EBUSY;
+
+__add:
+	pnp_add_irq_resource(dev, res->start, res->flags);
+	return 0;
+}
+
+#ifdef CONFIG_ISA_DMA_API
+static int pnp_assign_dma(struct pnp_dev *dev, struct pnp_dma *rule, int idx)
+{
+	struct resource *res, local_res;
+	int i;
+
+	/* DMA priority: this table is good for i386 */
+	static unsigned short xtab[8] = {
+		1, 3, 5, 6, 7, 0, 2, 4
+	};
+
+	res = pnp_find_resource(dev, rule->flags, IORESOURCE_DMA, idx);
+	if (res) {
+		pnp_dbg(&dev->dev, "  dma %d already set to %d flags %#lx\n",
+			idx, (int) res->start, res->flags);
+		return 0;
+	}
+
+	res = &local_res;
+	res->flags = rule->flags | IORESOURCE_AUTO;
+	res->start = -1;
+	res->end = -1;
+
+	if (!rule->map) {
+		res->flags |= IORESOURCE_DISABLED;
+		pnp_dbg(&dev->dev, "  dma %d disabled\n", idx);
+		goto __add;
+	}
+
+	for (i = 0; i < 8; i++) {
+		if (rule->map & (1 << xtab[i])) {
+			res->start = res->end = xtab[i];
+			if (pnp_check_dma(dev, res))
+				goto __add;
+		}
+	}
+
+	pnp_dbg(&dev->dev, "  couldn't assign dma %d\n", idx);
+	return -EBUSY;
+
+__add:
+	pnp_add_dma_resource(dev, res->start, res->flags);
+	return 0;
+}
+#endif /* CONFIG_ISA_DMA_API */
+
+void pnp_init_resources(struct pnp_dev *dev)
+{
+	pnp_free_resources(dev);
+}
+
+static void pnp_clean_resource_table(struct pnp_dev *dev)
+{
+	struct pnp_resource *pnp_res, *tmp;
+
+	list_for_each_entry_safe(pnp_res, tmp, &dev->resources, list) {
+		if (pnp_res->res.flags & IORESOURCE_AUTO)
+			pnp_free_resource(pnp_res);
+	}
+}
+
+/**
+ * pnp_assign_resources - assigns resources to the device based on the specified dependent number
+ * @dev: pointer to the desired device
+ * @set: the dependent function number
+ */
+static int pnp_assign_resources(struct pnp_dev *dev, int set)
+{
+	struct pnp_option *option;
+	int nport = 0, nmem = 0, nirq = 0;
+	int ndma __maybe_unused = 0;
+	int ret = 0;
+
+	pnp_dbg(&dev->dev, "pnp_assign_resources, try dependent set %d\n", set);
+	mutex_lock(&pnp_res_mutex);
+	pnp_clean_resource_table(dev);
+
+	list_for_each_entry(option, &dev->options, list) {
+		if (pnp_option_is_dependent(option) &&
+		    pnp_option_set(option) != set)
+				continue;
+
+		switch (option->type) {
+		case IORESOURCE_IO:
+			ret = pnp_assign_port(dev, &option->u.port, nport++);
+			break;
+		case IORESOURCE_MEM:
+			ret = pnp_assign_mem(dev, &option->u.mem, nmem++);
+			break;
+		case IORESOURCE_IRQ:
+			ret = pnp_assign_irq(dev, &option->u.irq, nirq++);
+			break;
+#ifdef CONFIG_ISA_DMA_API
+		case IORESOURCE_DMA:
+			ret = pnp_assign_dma(dev, &option->u.dma, ndma++);
+			break;
+#endif
+		default:
+			ret = -EINVAL;
+			break;
+		}
+		if (ret < 0)
+			break;
+	}
+
+	mutex_unlock(&pnp_res_mutex);
+	if (ret < 0) {
+		pnp_dbg(&dev->dev, "pnp_assign_resources failed (%d)\n", ret);
+		pnp_clean_resource_table(dev);
+	} else
+		dbg_pnp_show_resources(dev, "pnp_assign_resources succeeded");
+	return ret;
+}
+
+/**
+ * pnp_auto_config_dev - automatically assigns resources to a device
+ * @dev: pointer to the desired device
+ */
+int pnp_auto_config_dev(struct pnp_dev *dev)
+{
+	int i, ret;
+
+	if (!pnp_can_configure(dev)) {
+		pnp_dbg(&dev->dev, "configuration not supported\n");
+		return -ENODEV;
+	}
+
+	ret = pnp_assign_resources(dev, 0);
+	if (ret == 0)
+		return 0;
+
+	for (i = 1; i < dev->num_dependent_sets; i++) {
+		ret = pnp_assign_resources(dev, i);
+		if (ret == 0)
+			return 0;
+	}
+
+	dev_err(&dev->dev, "unable to assign resources\n");
+	return ret;
+}
+
+/**
+ * pnp_start_dev - low-level start of the PnP device
+ * @dev: pointer to the desired device
+ *
+ * assumes that resources have already been allocated
+ */
+int pnp_start_dev(struct pnp_dev *dev)
+{
+	if (!pnp_can_write(dev)) {
+		pnp_dbg(&dev->dev, "activation not supported\n");
+		return -EINVAL;
+	}
+
+	dbg_pnp_show_resources(dev, "pnp_start_dev");
+	if (dev->protocol->set(dev) < 0) {
+		dev_err(&dev->dev, "activation failed\n");
+		return -EIO;
+	}
+
+	dev_info(&dev->dev, "activated\n");
+	return 0;
+}
+EXPORT_SYMBOL(pnp_start_dev);
+
+/**
+ * pnp_stop_dev - low-level disable of the PnP device
+ * @dev: pointer to the desired device
+ *
+ * does not free resources
+ */
+int pnp_stop_dev(struct pnp_dev *dev)
+{
+	if (!pnp_can_disable(dev)) {
+		pnp_dbg(&dev->dev, "disabling not supported\n");
+		return -EINVAL;
+	}
+	if (dev->protocol->disable(dev) < 0) {
+		dev_err(&dev->dev, "disable failed\n");
+		return -EIO;
+	}
+
+	dev_info(&dev->dev, "disabled\n");
+	return 0;
+}
+EXPORT_SYMBOL(pnp_stop_dev);
+
+/**
+ * pnp_activate_dev - activates a PnP device for use
+ * @dev: pointer to the desired device
+ *
+ * does not validate or set resources so be careful.
+ */
+int pnp_activate_dev(struct pnp_dev *dev)
+{
+	int error;
+
+	if (dev->active)
+		return 0;
+
+	/* ensure resources are allocated */
+	if (pnp_auto_config_dev(dev))
+		return -EBUSY;
+
+	error = pnp_start_dev(dev);
+	if (error)
+		return error;
+
+	dev->active = 1;
+	return 0;
+}
+EXPORT_SYMBOL(pnp_activate_dev);
+
+/**
+ * pnp_disable_dev - disables device
+ * @dev: pointer to the desired device
+ *
+ * inform the correct pnp protocol so that resources can be used by other devices
+ */
+int pnp_disable_dev(struct pnp_dev *dev)
+{
+	int error;
+
+	if (!dev->active)
+		return 0;
+
+	error = pnp_stop_dev(dev);
+	if (error)
+		return error;
+
+	dev->active = 0;
+
+	/* release the resources so that other devices can use them */
+	mutex_lock(&pnp_res_mutex);
+	pnp_clean_resource_table(dev);
+	mutex_unlock(&pnp_res_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL(pnp_disable_dev);