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, 275 insertions, 0 deletions

diff --git a/drivers/mfd/88pm805.c b/drivers/mfd/88pm805.c
new file mode 100644
index 000000000..f5d666317
--- /dev/null
+++ b/drivers/mfd/88pm805.c
@@ -0,0 +1,275 @@
+/*
+ * Base driver for Marvell 88PM805
+ *
+ * Copyright (C) 2012 Marvell International Ltd.
+ * Haojian Zhuang <haojian.zhuang@marvell.com>
+ * Joseph(Yossi) Hanin <yhanin@marvell.com>
+ * Qiao Zhou <zhouqiao@marvell.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/irq.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/88pm80x.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+
+static const struct i2c_device_id pm80x_id_table[] = {
+	{ "88PM805" },
+	{} /* NULL terminated */
+};
+MODULE_DEVICE_TABLE(i2c, pm80x_id_table);
+
+/* Interrupt Number in 88PM805 */
+enum {
+	PM805_IRQ_LDO_OFF,	/*0 */
+	PM805_IRQ_SRC_DPLL_LOCK,	/*1 */
+	PM805_IRQ_CLIP_FAULT,
+	PM805_IRQ_MIC_CONFLICT,
+	PM805_IRQ_HP2_SHRT,
+	PM805_IRQ_HP1_SHRT,	/*5 */
+	PM805_IRQ_FINE_PLL_FAULT,
+	PM805_IRQ_RAW_PLL_FAULT,
+	PM805_IRQ_VOLP_BTN_DET,
+	PM805_IRQ_VOLM_BTN_DET,
+	PM805_IRQ_SHRT_BTN_DET,	/*10 */
+	PM805_IRQ_MIC_DET,	/*11 */
+
+	PM805_MAX_IRQ,
+};
+
+static struct resource codec_resources[] = {
+	/* Headset microphone insertion or removal */
+	DEFINE_RES_IRQ_NAMED(PM805_IRQ_MIC_DET, "micin"),
+
+	/* Audio short HP1 */
+	DEFINE_RES_IRQ_NAMED(PM805_IRQ_HP1_SHRT, "audio-short1"),
+
+	/* Audio short HP2 */
+	DEFINE_RES_IRQ_NAMED(PM805_IRQ_HP2_SHRT, "audio-short2"),
+};
+
+static const struct mfd_cell codec_devs[] = {
+	{
+	 .name = "88pm80x-codec",
+	 .num_resources = ARRAY_SIZE(codec_resources),
+	 .resources = &codec_resources[0],
+	 .id = -1,
+	 },
+};
+
+static const struct regmap_irq pm805_irqs[] = {
+	/* INT0 */
+	[PM805_IRQ_LDO_OFF] = {
+		.mask = PM805_INT1_HP1_SHRT,
+	},
+	[PM805_IRQ_SRC_DPLL_LOCK] = {
+		.mask = PM805_INT1_HP2_SHRT,
+	},
+	[PM805_IRQ_CLIP_FAULT] = {
+		.mask = PM805_INT1_MIC_CONFLICT,
+	},
+	[PM805_IRQ_MIC_CONFLICT] = {
+		.mask = PM805_INT1_CLIP_FAULT,
+	},
+	[PM805_IRQ_HP2_SHRT] = {
+		.mask = PM805_INT1_LDO_OFF,
+	},
+	[PM805_IRQ_HP1_SHRT] = {
+		.mask = PM805_INT1_SRC_DPLL_LOCK,
+	},
+	/* INT1 */
+	[PM805_IRQ_FINE_PLL_FAULT] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_MIC_DET,
+	},
+	[PM805_IRQ_RAW_PLL_FAULT] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_SHRT_BTN_DET,
+	},
+	[PM805_IRQ_VOLP_BTN_DET] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_VOLM_BTN_DET,
+	},
+	[PM805_IRQ_VOLM_BTN_DET] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_VOLP_BTN_DET,
+	},
+	[PM805_IRQ_SHRT_BTN_DET] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_RAW_PLL_FAULT,
+	},
+	[PM805_IRQ_MIC_DET] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_FINE_PLL_FAULT,
+	},
+};
+
+static int device_irq_init_805(struct pm80x_chip *chip)
+{
+	struct regmap *map = chip->regmap;
+	unsigned long flags = IRQF_ONESHOT;
+	int data, mask, ret = -EINVAL;
+
+	if (!map || !chip->irq) {
+		dev_err(chip->dev, "incorrect parameters\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * irq_mode defines the way of clearing interrupt. it's read-clear by
+	 * default.
+	 */
+	mask =
+	    PM805_STATUS0_INT_CLEAR | PM805_STATUS0_INV_INT |
+	    PM800_STATUS0_INT_MASK;
+
+	data = PM805_STATUS0_INT_CLEAR;
+	ret = regmap_update_bits(map, PM805_INT_STATUS0, mask, data);
+	/*
+	 * PM805_INT_STATUS is under 32K clock domain, so need to
+	 * add proper delay before the next I2C register access.
+	 */
+	usleep_range(1000, 3000);
+
+	if (ret < 0)
+		goto out;
+
+	ret =
+	    regmap_add_irq_chip(chip->regmap, chip->irq, flags, -1,
+				chip->regmap_irq_chip, &chip->irq_data);
+
+out:
+	return ret;
+}
+
+static void device_irq_exit_805(struct pm80x_chip *chip)
+{
+	regmap_del_irq_chip(chip->irq, chip->irq_data);
+}
+
+static const struct regmap_irq_chip pm805_irq_chip = {
+	.name = "88pm805",
+	.irqs = pm805_irqs,
+	.num_irqs = ARRAY_SIZE(pm805_irqs),
+
+	.num_regs = 2,
+	.status_base = PM805_INT_STATUS1,
+	.mask_base = PM805_INT_MASK1,
+	.ack_base = PM805_INT_STATUS1,
+};
+
+static int device_805_init(struct pm80x_chip *chip)
+{
+	int ret = 0;
+	struct regmap *map = chip->regmap;
+
+	if (!map) {
+		dev_err(chip->dev, "regmap is invalid\n");
+		return -EINVAL;
+	}
+
+	chip->regmap_irq_chip = &pm805_irq_chip;
+
+	ret = device_irq_init_805(chip);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to init pm805 irq!\n");
+		goto out_irq_init;
+	}
+
+	ret = mfd_add_devices(chip->dev, 0, &codec_devs[0],
+			      ARRAY_SIZE(codec_devs), &codec_resources[0], 0,
+			      NULL);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to add codec subdev\n");
+		goto out_codec;
+	} else
+		dev_info(chip->dev, "[%s]:Added mfd codec_devs\n", __func__);
+
+	return 0;
+
+out_codec:
+	device_irq_exit_805(chip);
+out_irq_init:
+	return ret;
+}
+
+static int pm805_probe(struct i2c_client *client)
+{
+	int ret = 0;
+	struct pm80x_chip *chip;
+	struct pm80x_platform_data *pdata = dev_get_platdata(&client->dev);
+
+	ret = pm80x_init(client);
+	if (ret) {
+		dev_err(&client->dev, "pm805_init fail!\n");
+		goto out_init;
+	}
+
+	chip = i2c_get_clientdata(client);
+
+	ret = device_805_init(chip);
+	if (ret) {
+		dev_err(chip->dev, "Failed to initialize 88pm805 devices\n");
+		goto err_805_init;
+	}
+
+	if (pdata && pdata->plat_config)
+		pdata->plat_config(chip, pdata);
+
+err_805_init:
+	pm80x_deinit();
+out_init:
+	return ret;
+}
+
+static void pm805_remove(struct i2c_client *client)
+{
+	struct pm80x_chip *chip = i2c_get_clientdata(client);
+
+	mfd_remove_devices(chip->dev);
+	device_irq_exit_805(chip);
+
+	pm80x_deinit();
+}
+
+static struct i2c_driver pm805_driver = {
+	.driver = {
+		.name = "88PM805",
+		.pm = pm_sleep_ptr(&pm80x_pm_ops),
+		},
+	.probe = pm805_probe,
+	.remove = pm805_remove,
+	.id_table = pm80x_id_table,
+};
+
+static int __init pm805_i2c_init(void)
+{
+	return i2c_add_driver(&pm805_driver);
+}
+subsys_initcall(pm805_i2c_init);
+
+static void __exit pm805_i2c_exit(void)
+{
+	i2c_del_driver(&pm805_driver);
+}
+module_exit(pm805_i2c_exit);
+
+MODULE_DESCRIPTION("PMIC Driver for Marvell 88PM805");
+MODULE_AUTHOR("Qiao Zhou <zhouqiao@marvell.com>");
+MODULE_LICENSE("GPL");