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, 601 insertions, 0 deletions

diff --git a/drivers/soc/aspeed/aspeed-uart-routing.c b/drivers/soc/aspeed/aspeed-uart-routing.c
new file mode 100644
index 000000000..b4b521b5d
--- /dev/null
+++ b/drivers/soc/aspeed/aspeed-uart-routing.c
@@ -0,0 +1,601 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2018 Google LLC
+ * Copyright (c) 2021 Aspeed Technology Inc.
+ */
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/platform_device.h>
+
+/* register offsets */
+#define HICR9	0x98
+#define HICRA	0x9c
+
+/* attributes options */
+#define UART_ROUTING_IO1	"io1"
+#define UART_ROUTING_IO2	"io2"
+#define UART_ROUTING_IO3	"io3"
+#define UART_ROUTING_IO4	"io4"
+#define UART_ROUTING_IO5	"io5"
+#define UART_ROUTING_IO6	"io6"
+#define UART_ROUTING_IO10	"io10"
+#define UART_ROUTING_UART1	"uart1"
+#define UART_ROUTING_UART2	"uart2"
+#define UART_ROUTING_UART3	"uart3"
+#define UART_ROUTING_UART4	"uart4"
+#define UART_ROUTING_UART5	"uart5"
+#define UART_ROUTING_UART6	"uart6"
+#define UART_ROUTING_UART10	"uart10"
+#define UART_ROUTING_RES	"reserved"
+
+struct aspeed_uart_routing {
+	struct regmap *map;
+	struct attribute_group const *attr_grp;
+};
+
+struct aspeed_uart_routing_selector {
+	struct device_attribute	dev_attr;
+	uint8_t reg;
+	uint8_t mask;
+	uint8_t shift;
+	const char *const options[];
+};
+
+#define to_routing_selector(_dev_attr)					\
+	container_of(_dev_attr, struct aspeed_uart_routing_selector, dev_attr)
+
+static ssize_t aspeed_uart_routing_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf);
+
+static ssize_t aspeed_uart_routing_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count);
+
+#define ROUTING_ATTR(_name) {					\
+	.attr = {.name = _name,					\
+		 .mode = VERIFY_OCTAL_PERMISSIONS(0644) },	\
+	.show = aspeed_uart_routing_show,			\
+	.store = aspeed_uart_routing_store,			\
+}
+
+/* routing selector for AST25xx */
+static struct aspeed_uart_routing_selector ast2500_io6_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO6),
+	.reg = HICR9,
+	.shift = 8,
+	.mask = 0xf,
+	.options = {
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_UART5,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_IO5,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2500_uart5_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART5),
+	.reg = HICRA,
+	.shift = 28,
+	.mask = 0xf,
+	.options = {
+		    UART_ROUTING_IO5,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_IO6,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2500_uart4_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART4),
+	.reg = HICRA,
+	.shift = 25,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_IO6,
+		    NULL,
+	},
+};
+
+static struct aspeed_uart_routing_selector ast2500_uart3_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART3),
+	.reg = HICRA,
+	.shift = 22,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_IO6,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2500_uart2_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART2),
+	.reg = HICRA,
+	.shift = 19,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_IO6,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2500_uart1_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART1),
+	.reg = HICRA,
+	.shift = 16,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_IO6,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2500_io5_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO5),
+	.reg = HICRA,
+	.shift = 12,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_UART5,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO6,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2500_io4_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO4),
+	.reg = HICRA,
+	.shift = 9,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_UART5,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO6,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2500_io3_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO3),
+	.reg = HICRA,
+	.shift = 6,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_UART5,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO6,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2500_io2_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO2),
+	.reg = HICRA,
+	.shift = 3,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_UART5,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_IO6,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2500_io1_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO1),
+	.reg = HICRA,
+	.shift = 0,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_UART5,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_IO6,
+		    NULL,
+		    },
+};
+
+static struct attribute *ast2500_uart_routing_attrs[] = {
+	&ast2500_io6_sel.dev_attr.attr,
+	&ast2500_uart5_sel.dev_attr.attr,
+	&ast2500_uart4_sel.dev_attr.attr,
+	&ast2500_uart3_sel.dev_attr.attr,
+	&ast2500_uart2_sel.dev_attr.attr,
+	&ast2500_uart1_sel.dev_attr.attr,
+	&ast2500_io5_sel.dev_attr.attr,
+	&ast2500_io4_sel.dev_attr.attr,
+	&ast2500_io3_sel.dev_attr.attr,
+	&ast2500_io2_sel.dev_attr.attr,
+	&ast2500_io1_sel.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ast2500_uart_routing_attr_group = {
+	.attrs = ast2500_uart_routing_attrs,
+};
+
+/* routing selector for AST26xx */
+static struct aspeed_uart_routing_selector ast2600_uart10_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART10),
+	.reg = HICR9,
+	.shift = 12,
+	.mask = 0xf,
+	.options = {
+		    UART_ROUTING_IO10,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+			UART_ROUTING_RES,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2600_io10_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO10),
+	.reg = HICR9,
+	.shift = 8,
+	.mask = 0xf,
+	.options = {
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+			UART_ROUTING_RES,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+			UART_ROUTING_RES,
+		    UART_ROUTING_UART10,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2600_uart4_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART4),
+	.reg = HICRA,
+	.shift = 25,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_IO10,
+		    NULL,
+	},
+};
+
+static struct aspeed_uart_routing_selector ast2600_uart3_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART3),
+	.reg = HICRA,
+	.shift = 22,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_IO10,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2600_uart2_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART2),
+	.reg = HICRA,
+	.shift = 19,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_IO10,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2600_uart1_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_UART1),
+	.reg = HICRA,
+	.shift = 16,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_IO10,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2600_io4_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO4),
+	.reg = HICRA,
+	.shift = 9,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_UART10,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO10,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2600_io3_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO3),
+	.reg = HICRA,
+	.shift = 6,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_UART10,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_IO1,
+		    UART_ROUTING_IO2,
+		    UART_ROUTING_IO10,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2600_io2_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO2),
+	.reg = HICRA,
+	.shift = 3,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_UART10,
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_IO10,
+		    NULL,
+		    },
+};
+
+static struct aspeed_uart_routing_selector ast2600_io1_sel = {
+	.dev_attr = ROUTING_ATTR(UART_ROUTING_IO1),
+	.reg = HICRA,
+	.shift = 0,
+	.mask = 0x7,
+	.options = {
+		    UART_ROUTING_UART1,
+		    UART_ROUTING_UART2,
+		    UART_ROUTING_UART3,
+		    UART_ROUTING_UART4,
+		    UART_ROUTING_UART10,
+		    UART_ROUTING_IO3,
+		    UART_ROUTING_IO4,
+		    UART_ROUTING_IO10,
+		    NULL,
+		    },
+};
+
+static struct attribute *ast2600_uart_routing_attrs[] = {
+	&ast2600_uart10_sel.dev_attr.attr,
+	&ast2600_io10_sel.dev_attr.attr,
+	&ast2600_uart4_sel.dev_attr.attr,
+	&ast2600_uart3_sel.dev_attr.attr,
+	&ast2600_uart2_sel.dev_attr.attr,
+	&ast2600_uart1_sel.dev_attr.attr,
+	&ast2600_io4_sel.dev_attr.attr,
+	&ast2600_io3_sel.dev_attr.attr,
+	&ast2600_io2_sel.dev_attr.attr,
+	&ast2600_io1_sel.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ast2600_uart_routing_attr_group = {
+	.attrs = ast2600_uart_routing_attrs,
+};
+
+static ssize_t aspeed_uart_routing_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct aspeed_uart_routing *uart_routing = dev_get_drvdata(dev);
+	struct aspeed_uart_routing_selector *sel = to_routing_selector(attr);
+	int val, pos, len;
+
+	regmap_read(uart_routing->map, sel->reg, &val);
+	val = (val >> sel->shift) & sel->mask;
+
+	len = 0;
+	for (pos = 0; sel->options[pos] != NULL; ++pos) {
+		if (pos == val)
+			len += sysfs_emit_at(buf, len, "[%s] ", sel->options[pos]);
+		else
+			len += sysfs_emit_at(buf, len, "%s ", sel->options[pos]);
+	}
+
+	if (val >= pos)
+		len += sysfs_emit_at(buf, len, "[unknown(%d)]", val);
+
+	len += sysfs_emit_at(buf, len, "\n");
+
+	return len;
+}
+
+static ssize_t aspeed_uart_routing_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	struct aspeed_uart_routing *uart_routing = dev_get_drvdata(dev);
+	struct aspeed_uart_routing_selector *sel = to_routing_selector(attr);
+	int val;
+
+	val = __sysfs_match_string(sel->options, -1, buf);
+	if (val < 0) {
+		dev_err(dev, "invalid value \"%s\"\n", buf);
+		return -EINVAL;
+	}
+
+	regmap_update_bits(uart_routing->map, sel->reg,
+			(sel->mask << sel->shift),
+			(val & sel->mask) << sel->shift);
+
+	return count;
+}
+
+static int aspeed_uart_routing_probe(struct platform_device *pdev)
+{
+	int rc;
+	struct device *dev = &pdev->dev;
+	struct aspeed_uart_routing *uart_routing;
+
+	uart_routing = devm_kzalloc(&pdev->dev, sizeof(*uart_routing), GFP_KERNEL);
+	if (!uart_routing)
+		return -ENOMEM;
+
+	uart_routing->map = syscon_node_to_regmap(dev->parent->of_node);
+	if (IS_ERR(uart_routing->map)) {
+		dev_err(dev, "cannot get regmap\n");
+		return PTR_ERR(uart_routing->map);
+	}
+
+	uart_routing->attr_grp = of_device_get_match_data(dev);
+
+	rc = sysfs_create_group(&dev->kobj, uart_routing->attr_grp);
+	if (rc < 0)
+		return rc;
+
+	dev_set_drvdata(dev, uart_routing);
+
+	dev_info(dev, "module loaded\n");
+
+	return 0;
+}
+
+static void aspeed_uart_routing_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct aspeed_uart_routing *uart_routing = platform_get_drvdata(pdev);
+
+	sysfs_remove_group(&dev->kobj, uart_routing->attr_grp);
+}
+
+static const struct of_device_id aspeed_uart_routing_table[] = {
+	{ .compatible = "aspeed,ast2400-uart-routing",
+	  .data = &ast2500_uart_routing_attr_group },
+	{ .compatible = "aspeed,ast2500-uart-routing",
+	  .data = &ast2500_uart_routing_attr_group },
+	{ .compatible = "aspeed,ast2600-uart-routing",
+	  .data = &ast2600_uart_routing_attr_group },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, aspeed_uart_routing_table);
+
+static struct platform_driver aspeed_uart_routing_driver = {
+	.driver = {
+		.name = "aspeed-uart-routing",
+		.of_match_table = aspeed_uart_routing_table,
+	},
+	.probe = aspeed_uart_routing_probe,
+	.remove = aspeed_uart_routing_remove,
+};
+
+module_platform_driver(aspeed_uart_routing_driver);
+
+MODULE_AUTHOR("Oskar Senft <osk@google.com>");
+MODULE_AUTHOR("Chia-Wei Wang <chiawei_wang@aspeedtech.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Driver to configure Aspeed UART routing");