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, 264 insertions, 0 deletions

diff --git a/drivers/ata/pata_imx.c b/drivers/ata/pata_imx.c
new file mode 100644
index 000000000..ad559058c
--- /dev/null
+++ b/drivers/ata/pata_imx.c
@@ -0,0 +1,264 @@
+/*
+ * Freescale iMX PATA driver
+ *
+ * Copyright (C) 2011 Arnaud Patard <arnaud.patard@rtp-net.org>
+ *
+ * Based on pata_platform - Copyright (C) 2006 - 2007  Paul Mundt
+ *
+ * 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.
+ *
+ * TODO:
+ * - dmaengine support
+ */
+
+#include <linux/ata.h>
+#include <linux/clk.h>
+#include <linux/libata.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define DRV_NAME "pata_imx"
+
+#define PATA_IMX_ATA_TIME_OFF		0x00
+#define PATA_IMX_ATA_TIME_ON		0x01
+#define PATA_IMX_ATA_TIME_1		0x02
+#define PATA_IMX_ATA_TIME_2W		0x03
+#define PATA_IMX_ATA_TIME_2R		0x04
+#define PATA_IMX_ATA_TIME_AX		0x05
+#define PATA_IMX_ATA_TIME_PIO_RDX	0x06
+#define PATA_IMX_ATA_TIME_4		0x07
+#define PATA_IMX_ATA_TIME_9		0x08
+
+#define PATA_IMX_ATA_CONTROL		0x24
+#define PATA_IMX_ATA_CTRL_FIFO_RST_B	(1<<7)
+#define PATA_IMX_ATA_CTRL_ATA_RST_B	(1<<6)
+#define PATA_IMX_ATA_CTRL_IORDY_EN	(1<<0)
+#define PATA_IMX_ATA_INT_EN		0x2C
+#define PATA_IMX_ATA_INTR_ATA_INTRQ2	(1<<3)
+#define PATA_IMX_DRIVE_DATA		0xA0
+#define PATA_IMX_DRIVE_CONTROL		0xD8
+
+static u32 pio_t4[] = { 30,  20,  15,  10,  10 };
+static u32 pio_t9[] = { 20,  15,  10,  10,  10 };
+static u32 pio_tA[] = { 35,  35,  35,  35,  35 };
+
+struct pata_imx_priv {
+	struct clk *clk;
+	/* timings/interrupt/control regs */
+	void __iomem *host_regs;
+	u32 ata_ctl;
+};
+
+static void pata_imx_set_timing(struct ata_device *adev,
+				struct pata_imx_priv *priv)
+{
+	struct ata_timing timing;
+	unsigned long clkrate;
+	u32 T, mode;
+
+	clkrate = clk_get_rate(priv->clk);
+
+	if (adev->pio_mode < XFER_PIO_0 || adev->pio_mode > XFER_PIO_4 ||
+	    !clkrate)
+		return;
+
+	T = 1000000000 / clkrate;
+	ata_timing_compute(adev, adev->pio_mode, &timing, T * 1000, 0);
+
+	mode = adev->pio_mode - XFER_PIO_0;
+
+	writeb(3, priv->host_regs + PATA_IMX_ATA_TIME_OFF);
+	writeb(3, priv->host_regs + PATA_IMX_ATA_TIME_ON);
+	writeb(timing.setup, priv->host_regs + PATA_IMX_ATA_TIME_1);
+	writeb(timing.act8b, priv->host_regs + PATA_IMX_ATA_TIME_2W);
+	writeb(timing.act8b, priv->host_regs + PATA_IMX_ATA_TIME_2R);
+	writeb(1, priv->host_regs + PATA_IMX_ATA_TIME_PIO_RDX);
+
+	writeb(pio_t4[mode] / T + 1, priv->host_regs + PATA_IMX_ATA_TIME_4);
+	writeb(pio_t9[mode] / T + 1, priv->host_regs + PATA_IMX_ATA_TIME_9);
+	writeb(pio_tA[mode] / T + 1, priv->host_regs + PATA_IMX_ATA_TIME_AX);
+}
+
+static void pata_imx_set_piomode(struct ata_port *ap, struct ata_device *adev)
+{
+	struct pata_imx_priv *priv = ap->host->private_data;
+	u32 val;
+
+	pata_imx_set_timing(adev, priv);
+
+	val = __raw_readl(priv->host_regs + PATA_IMX_ATA_CONTROL);
+	if (ata_pio_need_iordy(adev))
+		val |= PATA_IMX_ATA_CTRL_IORDY_EN;
+	else
+		val &= ~PATA_IMX_ATA_CTRL_IORDY_EN;
+	__raw_writel(val, priv->host_regs + PATA_IMX_ATA_CONTROL);
+}
+
+static const struct scsi_host_template pata_imx_sht = {
+	ATA_PIO_SHT(DRV_NAME),
+};
+
+static struct ata_port_operations pata_imx_port_ops = {
+	.inherits		= &ata_sff_port_ops,
+	.sff_data_xfer		= ata_sff_data_xfer32,
+	.cable_detect		= ata_cable_unknown,
+	.set_piomode		= pata_imx_set_piomode,
+};
+
+static void pata_imx_setup_port(struct ata_ioports *ioaddr)
+{
+	/* Fixup the port shift for platforms that need it */
+	ioaddr->data_addr	= ioaddr->cmd_addr + (ATA_REG_DATA    << 2);
+	ioaddr->error_addr	= ioaddr->cmd_addr + (ATA_REG_ERR     << 2);
+	ioaddr->feature_addr	= ioaddr->cmd_addr + (ATA_REG_FEATURE << 2);
+	ioaddr->nsect_addr	= ioaddr->cmd_addr + (ATA_REG_NSECT   << 2);
+	ioaddr->lbal_addr	= ioaddr->cmd_addr + (ATA_REG_LBAL    << 2);
+	ioaddr->lbam_addr	= ioaddr->cmd_addr + (ATA_REG_LBAM    << 2);
+	ioaddr->lbah_addr	= ioaddr->cmd_addr + (ATA_REG_LBAH    << 2);
+	ioaddr->device_addr	= ioaddr->cmd_addr + (ATA_REG_DEVICE  << 2);
+	ioaddr->status_addr	= ioaddr->cmd_addr + (ATA_REG_STATUS  << 2);
+	ioaddr->command_addr	= ioaddr->cmd_addr + (ATA_REG_CMD     << 2);
+}
+
+static int pata_imx_probe(struct platform_device *pdev)
+{
+	struct ata_host *host;
+	struct ata_port *ap;
+	struct pata_imx_priv *priv;
+	int irq = 0;
+	struct resource *io_res;
+	int ret;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	priv = devm_kzalloc(&pdev->dev,
+				sizeof(struct pata_imx_priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->clk = devm_clk_get_enabled(&pdev->dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(&pdev->dev, "Failed to get and enable clock\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	host = ata_host_alloc(&pdev->dev, 1);
+	if (!host)
+		return -ENOMEM;
+
+	host->private_data = priv;
+	ap = host->ports[0];
+
+	ap->ops = &pata_imx_port_ops;
+	ap->pio_mask = ATA_PIO4;
+	ap->flags |= ATA_FLAG_SLAVE_POSS;
+
+	priv->host_regs = devm_platform_get_and_ioremap_resource(pdev, 0, &io_res);
+	if (IS_ERR(priv->host_regs))
+		return PTR_ERR(priv->host_regs);
+
+	ap->ioaddr.cmd_addr = priv->host_regs + PATA_IMX_DRIVE_DATA;
+	ap->ioaddr.ctl_addr = priv->host_regs + PATA_IMX_DRIVE_CONTROL;
+
+	ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
+
+	pata_imx_setup_port(&ap->ioaddr);
+
+	ata_port_desc(ap, "cmd 0x%llx ctl 0x%llx",
+		(unsigned long long)io_res->start + PATA_IMX_DRIVE_DATA,
+		(unsigned long long)io_res->start + PATA_IMX_DRIVE_CONTROL);
+
+	/* deassert resets */
+	__raw_writel(PATA_IMX_ATA_CTRL_FIFO_RST_B |
+			PATA_IMX_ATA_CTRL_ATA_RST_B,
+			priv->host_regs + PATA_IMX_ATA_CONTROL);
+	/* enable interrupts */
+	__raw_writel(PATA_IMX_ATA_INTR_ATA_INTRQ2,
+			priv->host_regs + PATA_IMX_ATA_INT_EN);
+
+	/* activate */
+	ret = ata_host_activate(host, irq, ata_sff_interrupt, 0,
+				&pata_imx_sht);
+
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void pata_imx_remove(struct platform_device *pdev)
+{
+	struct ata_host *host = platform_get_drvdata(pdev);
+	struct pata_imx_priv *priv = host->private_data;
+
+	ata_host_detach(host);
+
+	__raw_writel(0, priv->host_regs + PATA_IMX_ATA_INT_EN);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int pata_imx_suspend(struct device *dev)
+{
+	struct ata_host *host = dev_get_drvdata(dev);
+	struct pata_imx_priv *priv = host->private_data;
+
+	ata_host_suspend(host, PMSG_SUSPEND);
+
+	__raw_writel(0, priv->host_regs + PATA_IMX_ATA_INT_EN);
+	priv->ata_ctl = __raw_readl(priv->host_regs + PATA_IMX_ATA_CONTROL);
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static int pata_imx_resume(struct device *dev)
+{
+	struct ata_host *host = dev_get_drvdata(dev);
+	struct pata_imx_priv *priv = host->private_data;
+
+	int ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	__raw_writel(priv->ata_ctl, priv->host_regs + PATA_IMX_ATA_CONTROL);
+
+	__raw_writel(PATA_IMX_ATA_INTR_ATA_INTRQ2,
+			priv->host_regs + PATA_IMX_ATA_INT_EN);
+
+	ata_host_resume(host);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(pata_imx_pm_ops, pata_imx_suspend, pata_imx_resume);
+
+static const struct of_device_id imx_pata_dt_ids[] = {
+	{
+		.compatible = "fsl,imx27-pata",
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, imx_pata_dt_ids);
+
+static struct platform_driver pata_imx_driver = {
+	.probe		= pata_imx_probe,
+	.remove		= pata_imx_remove,
+	.driver = {
+		.name		= DRV_NAME,
+		.of_match_table	= imx_pata_dt_ids,
+		.pm		= &pata_imx_pm_ops,
+	},
+};
+
+module_platform_driver(pata_imx_driver);
+
+MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>");
+MODULE_DESCRIPTION("low-level driver for iMX PATA");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);