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, 112 insertions, 0 deletions

diff --git a/drivers/pinctrl/mediatek/pinctrl-rt3883.c b/drivers/pinctrl/mediatek/pinctrl-rt3883.c
new file mode 100644
index 000000000..838bf811c
--- /dev/null
+++ b/drivers/pinctrl/mediatek/pinctrl-rt3883.c
@@ -0,0 +1,112 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include "pinctrl-mtmips.h"
+
+#define RT3883_GPIO_MODE_UART0_SHIFT	2
+#define RT3883_GPIO_MODE_UART0_MASK	0x7
+#define RT3883_GPIO_MODE_UART0(x)	((x) << RT3883_GPIO_MODE_UART0_SHIFT)
+#define RT3883_GPIO_MODE_UARTF		0x0
+#define RT3883_GPIO_MODE_PCM_UARTF	0x1
+#define RT3883_GPIO_MODE_PCM_I2S	0x2
+#define RT3883_GPIO_MODE_I2S_UARTF	0x3
+#define RT3883_GPIO_MODE_PCM_GPIO	0x4
+#define RT3883_GPIO_MODE_GPIO_UARTF	0x5
+#define RT3883_GPIO_MODE_GPIO_I2S	0x6
+#define RT3883_GPIO_MODE_GPIO		0x7
+
+#define RT3883_GPIO_MODE_I2C		0
+#define RT3883_GPIO_MODE_SPI		1
+#define RT3883_GPIO_MODE_UART1		5
+#define RT3883_GPIO_MODE_JTAG		6
+#define RT3883_GPIO_MODE_MDIO		7
+#define RT3883_GPIO_MODE_GE1		9
+#define RT3883_GPIO_MODE_GE2		10
+
+#define RT3883_GPIO_MODE_PCI_SHIFT	11
+#define RT3883_GPIO_MODE_PCI_MASK	0x7
+#define RT3883_GPIO_MODE_PCI		(RT3883_GPIO_MODE_PCI_MASK << RT3883_GPIO_MODE_PCI_SHIFT)
+#define RT3883_GPIO_MODE_LNA_A_SHIFT	16
+#define RT3883_GPIO_MODE_LNA_A_MASK	0x3
+#define _RT3883_GPIO_MODE_LNA_A(_x)	((_x) << RT3883_GPIO_MODE_LNA_A_SHIFT)
+#define RT3883_GPIO_MODE_LNA_A_GPIO	0x3
+#define RT3883_GPIO_MODE_LNA_A		_RT3883_GPIO_MODE_LNA_A(RT3883_GPIO_MODE_LNA_A_MASK)
+#define RT3883_GPIO_MODE_LNA_G_SHIFT	18
+#define RT3883_GPIO_MODE_LNA_G_MASK	0x3
+#define _RT3883_GPIO_MODE_LNA_G(_x)	((_x) << RT3883_GPIO_MODE_LNA_G_SHIFT)
+#define RT3883_GPIO_MODE_LNA_G_GPIO	0x3
+#define RT3883_GPIO_MODE_LNA_G		_RT3883_GPIO_MODE_LNA_G(RT3883_GPIO_MODE_LNA_G_MASK)
+
+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 uartf_grp[] = {
+	FUNC("uartf", RT3883_GPIO_MODE_UARTF, 7, 8),
+	FUNC("pcm uartf", RT3883_GPIO_MODE_PCM_UARTF, 7, 8),
+	FUNC("pcm i2s", RT3883_GPIO_MODE_PCM_I2S, 7, 8),
+	FUNC("i2s uartf", RT3883_GPIO_MODE_I2S_UARTF, 7, 8),
+	FUNC("pcm gpio", RT3883_GPIO_MODE_PCM_GPIO, 11, 4),
+	FUNC("gpio uartf", RT3883_GPIO_MODE_GPIO_UARTF, 7, 4),
+	FUNC("gpio i2s", RT3883_GPIO_MODE_GPIO_I2S, 7, 4),
+};
+static struct mtmips_pmx_func uartlite_grp[] = { FUNC("uartlite", 0, 15, 2) };
+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 lna_a_grp[] = { FUNC("lna a", 0, 32, 3) };
+static struct mtmips_pmx_func lna_g_grp[] = { FUNC("lna g", 0, 35, 3) };
+static struct mtmips_pmx_func pci_grp[] = {
+	FUNC("pci-dev", 0, 40, 32),
+	FUNC("pci-host2", 1, 40, 32),
+	FUNC("pci-host1", 2, 40, 32),
+	FUNC("pci-fnc", 3, 40, 32)
+};
+static struct mtmips_pmx_func ge1_grp[] = { FUNC("ge1", 0, 72, 12) };
+static struct mtmips_pmx_func ge2_grp[] = { FUNC("ge2", 0, 84, 12) };
+
+static struct mtmips_pmx_group rt3883_pinmux_data[] = {
+	GRP("i2c", i2c_grp, 1, RT3883_GPIO_MODE_I2C),
+	GRP("spi", spi_grp, 1, RT3883_GPIO_MODE_SPI),
+	GRP("uartf", uartf_grp, RT3883_GPIO_MODE_UART0_MASK,
+		RT3883_GPIO_MODE_UART0_SHIFT),
+	GRP("uartlite", uartlite_grp, 1, RT3883_GPIO_MODE_UART1),
+	GRP("jtag", jtag_grp, 1, RT3883_GPIO_MODE_JTAG),
+	GRP("mdio", mdio_grp, 1, RT3883_GPIO_MODE_MDIO),
+	GRP("lna a", lna_a_grp, 1, RT3883_GPIO_MODE_LNA_A),
+	GRP("lna g", lna_g_grp, 1, RT3883_GPIO_MODE_LNA_G),
+	GRP("pci", pci_grp, RT3883_GPIO_MODE_PCI_MASK,
+		RT3883_GPIO_MODE_PCI_SHIFT),
+	GRP("ge1", ge1_grp, 1, RT3883_GPIO_MODE_GE1),
+	GRP("ge2", ge2_grp, 1, RT3883_GPIO_MODE_GE2),
+	{ 0 }
+};
+
+static int rt3883_pinctrl_probe(struct platform_device *pdev)
+{
+	return mtmips_pinctrl_init(pdev, rt3883_pinmux_data);
+}
+
+static const struct of_device_id rt3883_pinctrl_match[] = {
+	{ .compatible = "ralink,rt3883-pinctrl" },
+	{ .compatible = "ralink,rt2880-pinmux" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, rt3883_pinctrl_match);
+
+static struct platform_driver rt3883_pinctrl_driver = {
+	.probe = rt3883_pinctrl_probe,
+	.driver = {
+		.name = "rt3883-pinctrl",
+		.of_match_table = rt3883_pinctrl_match,
+	},
+};
+
+static int __init rt3883_pinctrl_init(void)
+{
+	return platform_driver_register(&rt3883_pinctrl_driver);
+}
+core_initcall_sync(rt3883_pinctrl_init);
+
+MODULE_DESCRIPTION("MediaTek RT3883 Pinctrl Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("MTK_PINCTRL");