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, 280 insertions, 0 deletions

diff --git a/drivers/usb/phy/phy-ulpi.c b/drivers/usb/phy/phy-ulpi.c
new file mode 100644
index 000000000..4df63e67b
--- /dev/null
+++ b/drivers/usb/phy/phy-ulpi.c
@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Generic ULPI USB transceiver support
+ *
+ * Copyright (C) 2009 Daniel Mack <daniel@caiaq.de>
+ *
+ * Based on sources from
+ *
+ *   Sascha Hauer <s.hauer@pengutronix.de>
+ *   Freescale Semiconductors
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/usb.h>
+#include <linux/usb/otg.h>
+#include <linux/usb/ulpi.h>
+
+
+struct ulpi_info {
+	unsigned int	id;
+	char		*name;
+};
+
+#define ULPI_ID(vendor, product) (((vendor) << 16) | (product))
+#define ULPI_INFO(_id, _name)		\
+	{				\
+		.id	= (_id),	\
+		.name	= (_name),	\
+	}
+
+/* ULPI hardcoded IDs, used for probing */
+static struct ulpi_info ulpi_ids[] = {
+	ULPI_INFO(ULPI_ID(0x04cc, 0x1504), "NXP ISP1504"),
+	ULPI_INFO(ULPI_ID(0x0424, 0x0006), "SMSC USB331x"),
+	ULPI_INFO(ULPI_ID(0x0424, 0x0007), "SMSC USB3320"),
+	ULPI_INFO(ULPI_ID(0x0424, 0x0009), "SMSC USB334x"),
+	ULPI_INFO(ULPI_ID(0x0451, 0x1507), "TI TUSB1210"),
+};
+
+static int ulpi_set_otg_flags(struct usb_phy *phy)
+{
+	unsigned int flags = ULPI_OTG_CTRL_DP_PULLDOWN |
+			     ULPI_OTG_CTRL_DM_PULLDOWN;
+
+	if (phy->flags & ULPI_OTG_ID_PULLUP)
+		flags |= ULPI_OTG_CTRL_ID_PULLUP;
+
+	/*
+	 * ULPI Specification rev.1.1 default
+	 * for Dp/DmPulldown is enabled.
+	 */
+	if (phy->flags & ULPI_OTG_DP_PULLDOWN_DIS)
+		flags &= ~ULPI_OTG_CTRL_DP_PULLDOWN;
+
+	if (phy->flags & ULPI_OTG_DM_PULLDOWN_DIS)
+		flags &= ~ULPI_OTG_CTRL_DM_PULLDOWN;
+
+	if (phy->flags & ULPI_OTG_EXTVBUSIND)
+		flags |= ULPI_OTG_CTRL_EXTVBUSIND;
+
+	return usb_phy_io_write(phy, flags, ULPI_OTG_CTRL);
+}
+
+static int ulpi_set_fc_flags(struct usb_phy *phy)
+{
+	unsigned int flags = 0;
+
+	/*
+	 * ULPI Specification rev.1.1 default
+	 * for XcvrSelect is Full Speed.
+	 */
+	if (phy->flags & ULPI_FC_HS)
+		flags |= ULPI_FUNC_CTRL_HIGH_SPEED;
+	else if (phy->flags & ULPI_FC_LS)
+		flags |= ULPI_FUNC_CTRL_LOW_SPEED;
+	else if (phy->flags & ULPI_FC_FS4LS)
+		flags |= ULPI_FUNC_CTRL_FS4LS;
+	else
+		flags |= ULPI_FUNC_CTRL_FULL_SPEED;
+
+	if (phy->flags & ULPI_FC_TERMSEL)
+		flags |= ULPI_FUNC_CTRL_TERMSELECT;
+
+	/*
+	 * ULPI Specification rev.1.1 default
+	 * for OpMode is Normal Operation.
+	 */
+	if (phy->flags & ULPI_FC_OP_NODRV)
+		flags |= ULPI_FUNC_CTRL_OPMODE_NONDRIVING;
+	else if (phy->flags & ULPI_FC_OP_DIS_NRZI)
+		flags |= ULPI_FUNC_CTRL_OPMODE_DISABLE_NRZI;
+	else if (phy->flags & ULPI_FC_OP_NSYNC_NEOP)
+		flags |= ULPI_FUNC_CTRL_OPMODE_NOSYNC_NOEOP;
+	else
+		flags |= ULPI_FUNC_CTRL_OPMODE_NORMAL;
+
+	/*
+	 * ULPI Specification rev.1.1 default
+	 * for SuspendM is Powered.
+	 */
+	flags |= ULPI_FUNC_CTRL_SUSPENDM;
+
+	return usb_phy_io_write(phy, flags, ULPI_FUNC_CTRL);
+}
+
+static int ulpi_set_ic_flags(struct usb_phy *phy)
+{
+	unsigned int flags = 0;
+
+	if (phy->flags & ULPI_IC_AUTORESUME)
+		flags |= ULPI_IFC_CTRL_AUTORESUME;
+
+	if (phy->flags & ULPI_IC_EXTVBUS_INDINV)
+		flags |= ULPI_IFC_CTRL_EXTERNAL_VBUS;
+
+	if (phy->flags & ULPI_IC_IND_PASSTHRU)
+		flags |= ULPI_IFC_CTRL_PASSTHRU;
+
+	if (phy->flags & ULPI_IC_PROTECT_DIS)
+		flags |= ULPI_IFC_CTRL_PROTECT_IFC_DISABLE;
+
+	return usb_phy_io_write(phy, flags, ULPI_IFC_CTRL);
+}
+
+static int ulpi_set_flags(struct usb_phy *phy)
+{
+	int ret;
+
+	ret = ulpi_set_otg_flags(phy);
+	if (ret)
+		return ret;
+
+	ret = ulpi_set_ic_flags(phy);
+	if (ret)
+		return ret;
+
+	return ulpi_set_fc_flags(phy);
+}
+
+static int ulpi_check_integrity(struct usb_phy *phy)
+{
+	int ret, i;
+	unsigned int val = 0x55;
+
+	for (i = 0; i < 2; i++) {
+		ret = usb_phy_io_write(phy, val, ULPI_SCRATCH);
+		if (ret < 0)
+			return ret;
+
+		ret = usb_phy_io_read(phy, ULPI_SCRATCH);
+		if (ret < 0)
+			return ret;
+
+		if (ret != val) {
+			pr_err("ULPI integrity check: failed!");
+			return -ENODEV;
+		}
+		val = val << 1;
+	}
+
+	pr_info("ULPI integrity check: passed.\n");
+
+	return 0;
+}
+
+static int ulpi_init(struct usb_phy *phy)
+{
+	int i, vid, pid, ret;
+	u32 ulpi_id = 0;
+
+	for (i = 0; i < 4; i++) {
+		ret = usb_phy_io_read(phy, ULPI_PRODUCT_ID_HIGH - i);
+		if (ret < 0)
+			return ret;
+		ulpi_id = (ulpi_id << 8) | ret;
+	}
+	vid = ulpi_id & 0xffff;
+	pid = ulpi_id >> 16;
+
+	pr_info("ULPI transceiver vendor/product ID 0x%04x/0x%04x\n", vid, pid);
+
+	for (i = 0; i < ARRAY_SIZE(ulpi_ids); i++) {
+		if (ulpi_ids[i].id == ULPI_ID(vid, pid)) {
+			pr_info("Found %s ULPI transceiver.\n",
+				ulpi_ids[i].name);
+			break;
+		}
+	}
+
+	ret = ulpi_check_integrity(phy);
+	if (ret)
+		return ret;
+
+	return ulpi_set_flags(phy);
+}
+
+static int ulpi_set_host(struct usb_otg *otg, struct usb_bus *host)
+{
+	struct usb_phy *phy = otg->usb_phy;
+	unsigned int flags = usb_phy_io_read(phy, ULPI_IFC_CTRL);
+
+	if (!host) {
+		otg->host = NULL;
+		return 0;
+	}
+
+	otg->host = host;
+
+	flags &= ~(ULPI_IFC_CTRL_6_PIN_SERIAL_MODE |
+		   ULPI_IFC_CTRL_3_PIN_SERIAL_MODE |
+		   ULPI_IFC_CTRL_CARKITMODE);
+
+	if (phy->flags & ULPI_IC_6PIN_SERIAL)
+		flags |= ULPI_IFC_CTRL_6_PIN_SERIAL_MODE;
+	else if (phy->flags & ULPI_IC_3PIN_SERIAL)
+		flags |= ULPI_IFC_CTRL_3_PIN_SERIAL_MODE;
+	else if (phy->flags & ULPI_IC_CARKIT)
+		flags |= ULPI_IFC_CTRL_CARKITMODE;
+
+	return usb_phy_io_write(phy, flags, ULPI_IFC_CTRL);
+}
+
+static int ulpi_set_vbus(struct usb_otg *otg, bool on)
+{
+	struct usb_phy *phy = otg->usb_phy;
+	unsigned int flags = usb_phy_io_read(phy, ULPI_OTG_CTRL);
+
+	flags &= ~(ULPI_OTG_CTRL_DRVVBUS | ULPI_OTG_CTRL_DRVVBUS_EXT);
+
+	if (on) {
+		if (phy->flags & ULPI_OTG_DRVVBUS)
+			flags |= ULPI_OTG_CTRL_DRVVBUS;
+
+		if (phy->flags & ULPI_OTG_DRVVBUS_EXT)
+			flags |= ULPI_OTG_CTRL_DRVVBUS_EXT;
+	}
+
+	return usb_phy_io_write(phy, flags, ULPI_OTG_CTRL);
+}
+
+static void otg_ulpi_init(struct usb_phy *phy, struct usb_otg *otg,
+			  struct usb_phy_io_ops *ops,
+			  unsigned int flags)
+{
+	phy->label	= "ULPI";
+	phy->flags	= flags;
+	phy->io_ops	= ops;
+	phy->otg	= otg;
+	phy->init	= ulpi_init;
+
+	otg->usb_phy	= phy;
+	otg->set_host	= ulpi_set_host;
+	otg->set_vbus	= ulpi_set_vbus;
+}
+
+struct usb_phy *
+devm_otg_ulpi_create(struct device *dev,
+		     struct usb_phy_io_ops *ops,
+		     unsigned int flags)
+{
+	struct usb_phy *phy;
+	struct usb_otg *otg;
+
+	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
+	if (!phy)
+		return NULL;
+
+	otg = devm_kzalloc(dev, sizeof(*otg), GFP_KERNEL);
+	if (!otg) {
+		devm_kfree(dev, phy);
+		return NULL;
+	}
+
+	otg_ulpi_init(phy, otg, ops, flags);
+
+	return phy;
+}
+EXPORT_SYMBOL_GPL(devm_otg_ulpi_create);