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, 65 insertions, 0 deletions

diff --git a/drivers/pinctrl/mediatek/pinctrl-rt2880.c b/drivers/pinctrl/mediatek/pinctrl-rt2880.c
new file mode 100644
index 000000000..e7099325c
--- /dev/null
+++ b/drivers/pinctrl/mediatek/pinctrl-rt2880.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include "pinctrl-mtmips.h"
+
+#define RT2880_GPIO_MODE_I2C		BIT(0)
+#define RT2880_GPIO_MODE_UART0		BIT(1)
+#define RT2880_GPIO_MODE_SPI		BIT(2)
+#define RT2880_GPIO_MODE_UART1		BIT(3)
+#define RT2880_GPIO_MODE_JTAG		BIT(4)
+#define RT2880_GPIO_MODE_MDIO		BIT(5)
+#define RT2880_GPIO_MODE_SDRAM		BIT(6)
+#define RT2880_GPIO_MODE_PCI		BIT(7)
+
+static struct mtmips_pmx_func i2c_grp[] = { FUNC("i2c", 0, 1, 2) };
+static struct mtmips_pmx_func spi_grp[] = { FUNC("spi", 0, 3, 4) };
+static struct mtmips_pmx_func uartlite_grp[] = { FUNC("uartlite", 0, 7, 8) };
+static struct mtmips_pmx_func jtag_grp[] = { FUNC("jtag", 0, 17, 5) };
+static struct mtmips_pmx_func mdio_grp[] = { FUNC("mdio", 0, 22, 2) };
+static struct mtmips_pmx_func sdram_grp[] = { FUNC("sdram", 0, 24, 16) };
+static struct mtmips_pmx_func pci_grp[] = { FUNC("pci", 0, 40, 32) };
+
+static struct mtmips_pmx_group rt2880_pinmux_data_act[] = {
+	GRP("i2c", i2c_grp, 1, RT2880_GPIO_MODE_I2C),
+	GRP("spi", spi_grp, 1, RT2880_GPIO_MODE_SPI),
+	GRP("uartlite", uartlite_grp, 1, RT2880_GPIO_MODE_UART0),
+	GRP("jtag", jtag_grp, 1, RT2880_GPIO_MODE_JTAG),
+	GRP("mdio", mdio_grp, 1, RT2880_GPIO_MODE_MDIO),
+	GRP("sdram", sdram_grp, 1, RT2880_GPIO_MODE_SDRAM),
+	GRP("pci", pci_grp, 1, RT2880_GPIO_MODE_PCI),
+	{ 0 }
+};
+
+static int rt2880_pinctrl_probe(struct platform_device *pdev)
+{
+	return mtmips_pinctrl_init(pdev, rt2880_pinmux_data_act);
+}
+
+static const struct of_device_id rt2880_pinctrl_match[] = {
+	{ .compatible = "ralink,rt2880-pinctrl" },
+	{ .compatible = "ralink,rt2880-pinmux" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, rt2880_pinctrl_match);
+
+static struct platform_driver rt2880_pinctrl_driver = {
+	.probe = rt2880_pinctrl_probe,
+	.driver = {
+		.name = "rt2880-pinctrl",
+		.of_match_table = rt2880_pinctrl_match,
+	},
+};
+
+static int __init rt2880_pinctrl_init(void)
+{
+	return platform_driver_register(&rt2880_pinctrl_driver);
+}
+core_initcall_sync(rt2880_pinctrl_init);
+
+MODULE_DESCRIPTION("MediaTek RT2880 Pinctrl Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("MTK_PINCTRL");