x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 433 insertions, 0 deletions

diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c
new file mode 100644
index 000000000..d339b8680
--- /dev/null
+++ b/drivers/extcon/extcon-palmas.c
@@ -0,0 +1,433 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Palmas USB transceiver driver
+ *
+ * Copyright (C) 2013 Texas Instruments Incorporated - https://www.ti.com
+ * Author: Graeme Gregory <gg@slimlogic.co.uk>
+ * Author: Kishon Vijay Abraham I <kishon@ti.com>
+ * Based on twl6030_usb.c
+ * Author: Hema HK <hemahk@ti.com>
+ */
+
+#include <linux/devm-helpers.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/mfd/palmas.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/gpio/consumer.h>
+#include <linux/workqueue.h>
+
+#define USB_GPIO_DEBOUNCE_MS	20	/* ms */
+
+static const unsigned int palmas_extcon_cable[] = {
+	EXTCON_USB,
+	EXTCON_USB_HOST,
+	EXTCON_NONE,
+};
+
+static void palmas_usb_wakeup(struct palmas *palmas, int enable)
+{
+	if (enable)
+		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP,
+			PALMAS_USB_WAKEUP_ID_WK_UP_COMP);
+	else
+		palmas_write(palmas, PALMAS_USB_OTG_BASE, PALMAS_USB_WAKEUP, 0);
+}
+
+static irqreturn_t palmas_vbus_irq_handler(int irq, void *_palmas_usb)
+{
+	struct palmas_usb *palmas_usb = _palmas_usb;
+	struct extcon_dev *edev = palmas_usb->edev;
+	unsigned int vbus_line_state;
+
+	palmas_read(palmas_usb->palmas, PALMAS_INTERRUPT_BASE,
+		PALMAS_INT3_LINE_STATE, &vbus_line_state);
+
+	if (vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS) {
+		if (palmas_usb->linkstat != PALMAS_USB_STATE_VBUS) {
+			palmas_usb->linkstat = PALMAS_USB_STATE_VBUS;
+			extcon_set_state_sync(edev, EXTCON_USB, true);
+			dev_dbg(palmas_usb->dev, "USB cable is attached\n");
+		} else {
+			dev_dbg(palmas_usb->dev,
+				"Spurious connect event detected\n");
+		}
+	} else if (!(vbus_line_state & PALMAS_INT3_LINE_STATE_VBUS)) {
+		if (palmas_usb->linkstat == PALMAS_USB_STATE_VBUS) {
+			palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
+			extcon_set_state_sync(edev, EXTCON_USB, false);
+			dev_dbg(palmas_usb->dev, "USB cable is detached\n");
+		} else {
+			dev_dbg(palmas_usb->dev,
+				"Spurious disconnect event detected\n");
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
+{
+	unsigned int set, id_src;
+	struct palmas_usb *palmas_usb = _palmas_usb;
+	struct extcon_dev *edev = palmas_usb->edev;
+
+	palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+		PALMAS_USB_ID_INT_LATCH_SET, &set);
+	palmas_read(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+		PALMAS_USB_ID_INT_SRC, &id_src);
+
+	if ((set & PALMAS_USB_ID_INT_SRC_ID_GND) &&
+				(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
+		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+			PALMAS_USB_ID_INT_LATCH_CLR,
+			PALMAS_USB_ID_INT_EN_HI_CLR_ID_GND);
+		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
+		extcon_set_state_sync(edev, EXTCON_USB_HOST, true);
+		dev_dbg(palmas_usb->dev, "USB-HOST cable is attached\n");
+	} else if ((set & PALMAS_USB_ID_INT_SRC_ID_FLOAT) &&
+				(id_src & PALMAS_USB_ID_INT_SRC_ID_FLOAT)) {
+		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+			PALMAS_USB_ID_INT_LATCH_CLR,
+			PALMAS_USB_ID_INT_EN_HI_CLR_ID_FLOAT);
+		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
+		extcon_set_state_sync(edev, EXTCON_USB_HOST, false);
+		dev_dbg(palmas_usb->dev, "USB-HOST cable is detached\n");
+	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_ID) &&
+				(!(set & PALMAS_USB_ID_INT_SRC_ID_GND))) {
+		palmas_usb->linkstat = PALMAS_USB_STATE_DISCONNECT;
+		extcon_set_state_sync(edev, EXTCON_USB_HOST, false);
+		dev_dbg(palmas_usb->dev, "USB-HOST cable is detached\n");
+	} else if ((palmas_usb->linkstat == PALMAS_USB_STATE_DISCONNECT) &&
+				(id_src & PALMAS_USB_ID_INT_SRC_ID_GND)) {
+		palmas_usb->linkstat = PALMAS_USB_STATE_ID;
+		extcon_set_state_sync(edev, EXTCON_USB_HOST, true);
+		dev_dbg(palmas_usb->dev, "USB-HOST cable is attached\n");
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void palmas_gpio_id_detect(struct work_struct *work)
+{
+	int id;
+	struct palmas_usb *palmas_usb = container_of(to_delayed_work(work),
+						     struct palmas_usb,
+						     wq_detectid);
+	struct extcon_dev *edev = palmas_usb->edev;
+
+	if (!palmas_usb->id_gpiod)
+		return;
+
+	id = gpiod_get_value_cansleep(palmas_usb->id_gpiod);
+
+	if (id) {
+		extcon_set_state_sync(edev, EXTCON_USB_HOST, false);
+		dev_dbg(palmas_usb->dev, "USB-HOST cable is detached\n");
+	} else {
+		extcon_set_state_sync(edev, EXTCON_USB_HOST, true);
+		dev_dbg(palmas_usb->dev, "USB-HOST cable is attached\n");
+	}
+}
+
+static irqreturn_t palmas_gpio_id_irq_handler(int irq, void *_palmas_usb)
+{
+	struct palmas_usb *palmas_usb = _palmas_usb;
+
+	queue_delayed_work(system_power_efficient_wq, &palmas_usb->wq_detectid,
+			   palmas_usb->sw_debounce_jiffies);
+
+	return IRQ_HANDLED;
+}
+
+static void palmas_enable_irq(struct palmas_usb *palmas_usb)
+{
+	palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+		PALMAS_USB_VBUS_CTRL_SET,
+		PALMAS_USB_VBUS_CTRL_SET_VBUS_ACT_COMP);
+
+	if (palmas_usb->enable_id_detection) {
+		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+			     PALMAS_USB_ID_CTRL_SET,
+			     PALMAS_USB_ID_CTRL_SET_ID_ACT_COMP);
+
+		palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+			     PALMAS_USB_ID_INT_EN_HI_SET,
+			     PALMAS_USB_ID_INT_EN_HI_SET_ID_GND |
+			     PALMAS_USB_ID_INT_EN_HI_SET_ID_FLOAT);
+	}
+
+	if (palmas_usb->enable_vbus_detection)
+		palmas_vbus_irq_handler(palmas_usb->vbus_irq, palmas_usb);
+
+	/* cold plug for host mode needs this delay */
+	if (palmas_usb->enable_id_detection) {
+		msleep(30);
+		palmas_id_irq_handler(palmas_usb->id_irq, palmas_usb);
+	}
+}
+
+static int palmas_usb_probe(struct platform_device *pdev)
+{
+	struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
+	struct palmas_usb_platform_data	*pdata = dev_get_platdata(&pdev->dev);
+	struct device_node *node = pdev->dev.of_node;
+	struct palmas_usb *palmas_usb;
+	int status;
+
+	if (!palmas) {
+		dev_err(&pdev->dev, "failed to get valid parent\n");
+		return -EINVAL;
+	}
+
+	palmas_usb = devm_kzalloc(&pdev->dev, sizeof(*palmas_usb), GFP_KERNEL);
+	if (!palmas_usb)
+		return -ENOMEM;
+
+	if (node && !pdata) {
+		palmas_usb->wakeup = of_property_read_bool(node, "ti,wakeup");
+		palmas_usb->enable_id_detection = of_property_read_bool(node,
+						"ti,enable-id-detection");
+		palmas_usb->enable_vbus_detection = of_property_read_bool(node,
+						"ti,enable-vbus-detection");
+	} else {
+		palmas_usb->wakeup = true;
+		palmas_usb->enable_id_detection = true;
+		palmas_usb->enable_vbus_detection = true;
+
+		if (pdata)
+			palmas_usb->wakeup = pdata->wakeup;
+	}
+
+	palmas_usb->id_gpiod = devm_gpiod_get_optional(&pdev->dev, "id",
+							GPIOD_IN);
+	if (IS_ERR(palmas_usb->id_gpiod))
+		return dev_err_probe(&pdev->dev, PTR_ERR(palmas_usb->id_gpiod),
+				     "failed to get id gpio\n");
+
+	palmas_usb->vbus_gpiod = devm_gpiod_get_optional(&pdev->dev, "vbus",
+							GPIOD_IN);
+	if (IS_ERR(palmas_usb->vbus_gpiod))
+		return dev_err_probe(&pdev->dev, PTR_ERR(palmas_usb->vbus_gpiod),
+				     "failed to get id gpio\n");
+
+	if (palmas_usb->enable_id_detection && palmas_usb->id_gpiod) {
+		palmas_usb->enable_id_detection = false;
+		palmas_usb->enable_gpio_id_detection = true;
+	}
+
+	if (palmas_usb->enable_vbus_detection && palmas_usb->vbus_gpiod) {
+		palmas_usb->enable_vbus_detection = false;
+		palmas_usb->enable_gpio_vbus_detection = true;
+	}
+
+	if (palmas_usb->enable_gpio_id_detection) {
+		u32 debounce;
+
+		if (of_property_read_u32(node, "debounce-delay-ms", &debounce))
+			debounce = USB_GPIO_DEBOUNCE_MS;
+
+		status = gpiod_set_debounce(palmas_usb->id_gpiod,
+					    debounce * 1000);
+		if (status < 0)
+			palmas_usb->sw_debounce_jiffies = msecs_to_jiffies(debounce);
+	}
+
+	status = devm_delayed_work_autocancel(&pdev->dev,
+					      &palmas_usb->wq_detectid,
+					      palmas_gpio_id_detect);
+	if (status)
+		return status;
+
+	palmas->usb = palmas_usb;
+	palmas_usb->palmas = palmas;
+
+	palmas_usb->dev	 = &pdev->dev;
+
+	palmas_usb_wakeup(palmas, palmas_usb->wakeup);
+
+	platform_set_drvdata(pdev, palmas_usb);
+
+	palmas_usb->edev = devm_extcon_dev_allocate(&pdev->dev,
+						    palmas_extcon_cable);
+	if (IS_ERR(palmas_usb->edev)) {
+		dev_err(&pdev->dev, "failed to allocate extcon device\n");
+		return -ENOMEM;
+	}
+
+	status = devm_extcon_dev_register(&pdev->dev, palmas_usb->edev);
+	if (status) {
+		dev_err(&pdev->dev, "failed to register extcon device\n");
+		return status;
+	}
+
+	if (palmas_usb->enable_id_detection) {
+		palmas_usb->id_otg_irq = regmap_irq_get_virq(palmas->irq_data,
+							     PALMAS_ID_OTG_IRQ);
+		palmas_usb->id_irq = regmap_irq_get_virq(palmas->irq_data,
+							 PALMAS_ID_IRQ);
+		status = devm_request_threaded_irq(palmas_usb->dev,
+				palmas_usb->id_irq,
+				NULL, palmas_id_irq_handler,
+				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING |
+				IRQF_ONESHOT,
+				"palmas_usb_id", palmas_usb);
+		if (status < 0) {
+			dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
+					palmas_usb->id_irq, status);
+			return status;
+		}
+	} else if (palmas_usb->enable_gpio_id_detection) {
+		palmas_usb->gpio_id_irq = gpiod_to_irq(palmas_usb->id_gpiod);
+		if (palmas_usb->gpio_id_irq < 0) {
+			dev_err(&pdev->dev, "failed to get id irq\n");
+			return palmas_usb->gpio_id_irq;
+		}
+		status = devm_request_threaded_irq(&pdev->dev,
+						   palmas_usb->gpio_id_irq,
+						   NULL,
+						   palmas_gpio_id_irq_handler,
+						   IRQF_TRIGGER_RISING |
+						   IRQF_TRIGGER_FALLING |
+						   IRQF_ONESHOT,
+						   "palmas_usb_id",
+						   palmas_usb);
+		if (status < 0) {
+			dev_err(&pdev->dev,
+				"failed to request handler for id irq\n");
+			return status;
+		}
+	}
+
+	if (palmas_usb->enable_vbus_detection) {
+		palmas_usb->vbus_otg_irq = regmap_irq_get_virq(palmas->irq_data,
+						       PALMAS_VBUS_OTG_IRQ);
+		palmas_usb->vbus_irq = regmap_irq_get_virq(palmas->irq_data,
+							   PALMAS_VBUS_IRQ);
+		status = devm_request_threaded_irq(palmas_usb->dev,
+				palmas_usb->vbus_irq, NULL,
+				palmas_vbus_irq_handler,
+				IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING |
+				IRQF_ONESHOT,
+				"palmas_usb_vbus", palmas_usb);
+		if (status < 0) {
+			dev_err(&pdev->dev, "can't get IRQ %d, err %d\n",
+					palmas_usb->vbus_irq, status);
+			return status;
+		}
+	} else if (palmas_usb->enable_gpio_vbus_detection) {
+		/* remux GPIO_1 as VBUSDET */
+		status = palmas_update_bits(palmas,
+			PALMAS_PU_PD_OD_BASE,
+			PALMAS_PRIMARY_SECONDARY_PAD1,
+			PALMAS_PRIMARY_SECONDARY_PAD1_GPIO_1_MASK,
+			(1 << PALMAS_PRIMARY_SECONDARY_PAD1_GPIO_1_SHIFT));
+		if (status < 0) {
+			dev_err(&pdev->dev, "can't remux GPIO1\n");
+			return status;
+		}
+
+		palmas_usb->vbus_otg_irq = regmap_irq_get_virq(palmas->irq_data,
+						       PALMAS_VBUS_OTG_IRQ);
+		palmas_usb->gpio_vbus_irq = gpiod_to_irq(palmas_usb->vbus_gpiod);
+		if (palmas_usb->gpio_vbus_irq < 0) {
+			dev_err(&pdev->dev, "failed to get vbus irq\n");
+			return palmas_usb->gpio_vbus_irq;
+		}
+		status = devm_request_threaded_irq(&pdev->dev,
+						palmas_usb->gpio_vbus_irq,
+						NULL,
+						palmas_vbus_irq_handler,
+						IRQF_TRIGGER_FALLING |
+						IRQF_TRIGGER_RISING |
+						IRQF_ONESHOT,
+						"palmas_usb_vbus",
+						palmas_usb);
+		if (status < 0) {
+			dev_err(&pdev->dev,
+				"failed to request handler for vbus irq\n");
+			return status;
+		}
+	}
+
+	palmas_enable_irq(palmas_usb);
+	/* perform initial detection */
+	if (palmas_usb->enable_gpio_vbus_detection)
+		palmas_vbus_irq_handler(palmas_usb->gpio_vbus_irq, palmas_usb);
+	palmas_gpio_id_detect(&palmas_usb->wq_detectid.work);
+	device_set_wakeup_capable(&pdev->dev, true);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int palmas_usb_suspend(struct device *dev)
+{
+	struct palmas_usb *palmas_usb = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev)) {
+		if (palmas_usb->enable_vbus_detection)
+			enable_irq_wake(palmas_usb->vbus_irq);
+		if (palmas_usb->enable_gpio_vbus_detection)
+			enable_irq_wake(palmas_usb->gpio_vbus_irq);
+		if (palmas_usb->enable_id_detection)
+			enable_irq_wake(palmas_usb->id_irq);
+		if (palmas_usb->enable_gpio_id_detection)
+			enable_irq_wake(palmas_usb->gpio_id_irq);
+	}
+	return 0;
+}
+
+static int palmas_usb_resume(struct device *dev)
+{
+	struct palmas_usb *palmas_usb = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev)) {
+		if (palmas_usb->enable_vbus_detection)
+			disable_irq_wake(palmas_usb->vbus_irq);
+		if (palmas_usb->enable_gpio_vbus_detection)
+			disable_irq_wake(palmas_usb->gpio_vbus_irq);
+		if (palmas_usb->enable_id_detection)
+			disable_irq_wake(palmas_usb->id_irq);
+		if (palmas_usb->enable_gpio_id_detection)
+			disable_irq_wake(palmas_usb->gpio_id_irq);
+	}
+
+	/* check if GPIO states changed while suspend/resume */
+	if (palmas_usb->enable_gpio_vbus_detection)
+		palmas_vbus_irq_handler(palmas_usb->gpio_vbus_irq, palmas_usb);
+	palmas_gpio_id_detect(&palmas_usb->wq_detectid.work);
+
+	return 0;
+};
+#endif
+
+static SIMPLE_DEV_PM_OPS(palmas_pm_ops, palmas_usb_suspend, palmas_usb_resume);
+
+static const struct of_device_id of_palmas_match_tbl[] = {
+	{ .compatible = "ti,palmas-usb", },
+	{ .compatible = "ti,palmas-usb-vid", },
+	{ .compatible = "ti,twl6035-usb", },
+	{ .compatible = "ti,twl6035-usb-vid", },
+	{ /* end */ }
+};
+
+static struct platform_driver palmas_usb_driver = {
+	.probe = palmas_usb_probe,
+	.driver = {
+		.name = "palmas-usb",
+		.of_match_table = of_palmas_match_tbl,
+		.pm = &palmas_pm_ops,
+	},
+};
+
+module_platform_driver(palmas_usb_driver);
+
+MODULE_ALIAS("platform:palmas-usb");
+MODULE_AUTHOR("Graeme Gregory <gg@slimlogic.co.uk>");
+MODULE_DESCRIPTION("Palmas USB transceiver driver");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(of, of_palmas_match_tbl);