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, 459 insertions, 0 deletions

diff --git a/drivers/mfd/as3722.c b/drivers/mfd/as3722.c
new file mode 100644
index 000000000..7ab6fcc9c
--- /dev/null
+++ b/drivers/mfd/as3722.c
@@ -0,0 +1,459 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Core driver for ams AS3722 PMICs
+ *
+ * Copyright (C) 2013 AMS AG
+ * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
+ *
+ * Author: Florian Lobmaier <florian.lobmaier@ams.com>
+ * Author: Laxman Dewangan <ldewangan@nvidia.com>
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/as3722.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define AS3722_DEVICE_ID	0x0C
+
+static const struct resource as3722_rtc_resource[] = {
+	DEFINE_RES_IRQ_NAMED(AS3722_IRQ_RTC_ALARM, "as3722-rtc-alarm"),
+};
+
+static const struct resource as3722_adc_resource[] = {
+	DEFINE_RES_IRQ_NAMED(AS3722_IRQ_ADC, "as3722-adc"),
+};
+
+static const struct mfd_cell as3722_devs[] = {
+	{
+		.name = "as3722-pinctrl",
+	},
+	{
+		.name = "as3722-regulator",
+	},
+	{
+		.name = "as3722-rtc",
+		.num_resources = ARRAY_SIZE(as3722_rtc_resource),
+		.resources = as3722_rtc_resource,
+	},
+	{
+		.name = "as3722-adc",
+		.num_resources = ARRAY_SIZE(as3722_adc_resource),
+		.resources = as3722_adc_resource,
+	},
+	{
+		.name = "as3722-power-off",
+	},
+	{
+		.name = "as3722-wdt",
+	},
+};
+
+static const struct regmap_irq as3722_irqs[] = {
+	/* INT1 IRQs */
+	[AS3722_IRQ_LID] = {
+		.mask = AS3722_INTERRUPT_MASK1_LID,
+	},
+	[AS3722_IRQ_ACOK] = {
+		.mask = AS3722_INTERRUPT_MASK1_ACOK,
+	},
+	[AS3722_IRQ_ENABLE1] = {
+		.mask = AS3722_INTERRUPT_MASK1_ENABLE1,
+	},
+	[AS3722_IRQ_OCCUR_ALARM_SD0] = {
+		.mask = AS3722_INTERRUPT_MASK1_OCURR_ALARM_SD0,
+	},
+	[AS3722_IRQ_ONKEY_LONG_PRESS] = {
+		.mask = AS3722_INTERRUPT_MASK1_ONKEY_LONG,
+	},
+	[AS3722_IRQ_ONKEY] = {
+		.mask = AS3722_INTERRUPT_MASK1_ONKEY,
+	},
+	[AS3722_IRQ_OVTMP] = {
+		.mask = AS3722_INTERRUPT_MASK1_OVTMP,
+	},
+	[AS3722_IRQ_LOWBAT] = {
+		.mask = AS3722_INTERRUPT_MASK1_LOWBAT,
+	},
+
+	/* INT2 IRQs */
+	[AS3722_IRQ_SD0_LV] = {
+		.mask = AS3722_INTERRUPT_MASK2_SD0_LV,
+		.reg_offset = 1,
+	},
+	[AS3722_IRQ_SD1_LV] = {
+		.mask = AS3722_INTERRUPT_MASK2_SD1_LV,
+		.reg_offset = 1,
+	},
+	[AS3722_IRQ_SD2_LV] = {
+		.mask = AS3722_INTERRUPT_MASK2_SD2345_LV,
+		.reg_offset = 1,
+	},
+	[AS3722_IRQ_PWM1_OV_PROT] = {
+		.mask = AS3722_INTERRUPT_MASK2_PWM1_OV_PROT,
+		.reg_offset = 1,
+	},
+	[AS3722_IRQ_PWM2_OV_PROT] = {
+		.mask = AS3722_INTERRUPT_MASK2_PWM2_OV_PROT,
+		.reg_offset = 1,
+	},
+	[AS3722_IRQ_ENABLE2] = {
+		.mask = AS3722_INTERRUPT_MASK2_ENABLE2,
+		.reg_offset = 1,
+	},
+	[AS3722_IRQ_SD6_LV] = {
+		.mask = AS3722_INTERRUPT_MASK2_SD6_LV,
+		.reg_offset = 1,
+	},
+	[AS3722_IRQ_RTC_REP] = {
+		.mask = AS3722_INTERRUPT_MASK2_RTC_REP,
+		.reg_offset = 1,
+	},
+
+	/* INT3 IRQs */
+	[AS3722_IRQ_RTC_ALARM] = {
+		.mask = AS3722_INTERRUPT_MASK3_RTC_ALARM,
+		.reg_offset = 2,
+	},
+	[AS3722_IRQ_GPIO1] = {
+		.mask = AS3722_INTERRUPT_MASK3_GPIO1,
+		.reg_offset = 2,
+	},
+	[AS3722_IRQ_GPIO2] = {
+		.mask = AS3722_INTERRUPT_MASK3_GPIO2,
+		.reg_offset = 2,
+	},
+	[AS3722_IRQ_GPIO3] = {
+		.mask = AS3722_INTERRUPT_MASK3_GPIO3,
+		.reg_offset = 2,
+	},
+	[AS3722_IRQ_GPIO4] = {
+		.mask = AS3722_INTERRUPT_MASK3_GPIO4,
+		.reg_offset = 2,
+	},
+	[AS3722_IRQ_GPIO5] = {
+		.mask = AS3722_INTERRUPT_MASK3_GPIO5,
+		.reg_offset = 2,
+	},
+	[AS3722_IRQ_WATCHDOG] = {
+		.mask = AS3722_INTERRUPT_MASK3_WATCHDOG,
+		.reg_offset = 2,
+	},
+	[AS3722_IRQ_ENABLE3] = {
+		.mask = AS3722_INTERRUPT_MASK3_ENABLE3,
+		.reg_offset = 2,
+	},
+
+	/* INT4 IRQs */
+	[AS3722_IRQ_TEMP_SD0_SHUTDOWN] = {
+		.mask = AS3722_INTERRUPT_MASK4_TEMP_SD0_SHUTDOWN,
+		.reg_offset = 3,
+	},
+	[AS3722_IRQ_TEMP_SD1_SHUTDOWN] = {
+		.mask = AS3722_INTERRUPT_MASK4_TEMP_SD1_SHUTDOWN,
+		.reg_offset = 3,
+	},
+	[AS3722_IRQ_TEMP_SD2_SHUTDOWN] = {
+		.mask = AS3722_INTERRUPT_MASK4_TEMP_SD6_SHUTDOWN,
+		.reg_offset = 3,
+	},
+	[AS3722_IRQ_TEMP_SD0_ALARM] = {
+		.mask = AS3722_INTERRUPT_MASK4_TEMP_SD0_ALARM,
+		.reg_offset = 3,
+	},
+	[AS3722_IRQ_TEMP_SD1_ALARM] = {
+		.mask = AS3722_INTERRUPT_MASK4_TEMP_SD1_ALARM,
+		.reg_offset = 3,
+	},
+	[AS3722_IRQ_TEMP_SD6_ALARM] = {
+		.mask = AS3722_INTERRUPT_MASK4_TEMP_SD6_ALARM,
+		.reg_offset = 3,
+	},
+	[AS3722_IRQ_OCCUR_ALARM_SD6] = {
+		.mask = AS3722_INTERRUPT_MASK4_OCCUR_ALARM_SD6,
+		.reg_offset = 3,
+	},
+	[AS3722_IRQ_ADC] = {
+		.mask = AS3722_INTERRUPT_MASK4_ADC,
+		.reg_offset = 3,
+	},
+};
+
+static const struct regmap_irq_chip as3722_irq_chip = {
+	.name = "as3722",
+	.irqs = as3722_irqs,
+	.num_irqs = ARRAY_SIZE(as3722_irqs),
+	.num_regs = 4,
+	.status_base = AS3722_INTERRUPT_STATUS1_REG,
+	.mask_base = AS3722_INTERRUPT_MASK1_REG,
+};
+
+static int as3722_check_device_id(struct as3722 *as3722)
+{
+	u32 val;
+	int ret;
+
+	/* Check that this is actually a AS3722 */
+	ret = as3722_read(as3722, AS3722_ASIC_ID1_REG, &val);
+	if (ret < 0) {
+		dev_err(as3722->dev, "ASIC_ID1 read failed: %d\n", ret);
+		return ret;
+	}
+
+	if (val != AS3722_DEVICE_ID) {
+		dev_err(as3722->dev, "Device is not AS3722, ID is 0x%x\n", val);
+		return -ENODEV;
+	}
+
+	ret = as3722_read(as3722, AS3722_ASIC_ID2_REG, &val);
+	if (ret < 0) {
+		dev_err(as3722->dev, "ASIC_ID2 read failed: %d\n", ret);
+		return ret;
+	}
+
+	dev_info(as3722->dev, "AS3722 with revision 0x%x found\n", val);
+	return 0;
+}
+
+static int as3722_configure_pullups(struct as3722 *as3722)
+{
+	int ret;
+	u32 val = 0;
+
+	if (as3722->en_intern_int_pullup)
+		val |= AS3722_INT_PULL_UP;
+	if (as3722->en_intern_i2c_pullup)
+		val |= AS3722_I2C_PULL_UP;
+
+	ret = as3722_update_bits(as3722, AS3722_IOVOLTAGE_REG,
+			AS3722_INT_PULL_UP | AS3722_I2C_PULL_UP, val);
+	if (ret < 0)
+		dev_err(as3722->dev, "IOVOLTAGE_REG update failed: %d\n", ret);
+	return ret;
+}
+
+static const struct regmap_range as3722_readable_ranges[] = {
+	regmap_reg_range(AS3722_SD0_VOLTAGE_REG, AS3722_SD6_VOLTAGE_REG),
+	regmap_reg_range(AS3722_GPIO0_CONTROL_REG, AS3722_LDO7_VOLTAGE_REG),
+	regmap_reg_range(AS3722_LDO9_VOLTAGE_REG, AS3722_REG_SEQU_MOD3_REG),
+	regmap_reg_range(AS3722_SD_PHSW_CTRL_REG, AS3722_PWM_CONTROL_H_REG),
+	regmap_reg_range(AS3722_WATCHDOG_TIMER_REG, AS3722_WATCHDOG_TIMER_REG),
+	regmap_reg_range(AS3722_WATCHDOG_SOFTWARE_SIGNAL_REG,
+					AS3722_BATTERY_VOLTAGE_MONITOR2_REG),
+	regmap_reg_range(AS3722_SD_CONTROL_REG, AS3722_PWM_VCONTROL4_REG),
+	regmap_reg_range(AS3722_BB_CHARGER_REG, AS3722_SRAM_REG),
+	regmap_reg_range(AS3722_RTC_ACCESS_REG, AS3722_RTC_ACCESS_REG),
+	regmap_reg_range(AS3722_RTC_STATUS_REG, AS3722_TEMP_STATUS_REG),
+	regmap_reg_range(AS3722_ADC0_CONTROL_REG, AS3722_ADC_CONFIGURATION_REG),
+	regmap_reg_range(AS3722_ASIC_ID1_REG, AS3722_ASIC_ID2_REG),
+	regmap_reg_range(AS3722_LOCK_REG, AS3722_LOCK_REG),
+	regmap_reg_range(AS3722_FUSE7_REG, AS3722_FUSE7_REG),
+};
+
+static const struct regmap_access_table as3722_readable_table = {
+	.yes_ranges = as3722_readable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(as3722_readable_ranges),
+};
+
+static const struct regmap_range as3722_writable_ranges[] = {
+	regmap_reg_range(AS3722_SD0_VOLTAGE_REG, AS3722_SD6_VOLTAGE_REG),
+	regmap_reg_range(AS3722_GPIO0_CONTROL_REG, AS3722_LDO7_VOLTAGE_REG),
+	regmap_reg_range(AS3722_LDO9_VOLTAGE_REG, AS3722_GPIO_SIGNAL_OUT_REG),
+	regmap_reg_range(AS3722_REG_SEQU_MOD1_REG, AS3722_REG_SEQU_MOD3_REG),
+	regmap_reg_range(AS3722_SD_PHSW_CTRL_REG, AS3722_PWM_CONTROL_H_REG),
+	regmap_reg_range(AS3722_WATCHDOG_TIMER_REG, AS3722_WATCHDOG_TIMER_REG),
+	regmap_reg_range(AS3722_WATCHDOG_SOFTWARE_SIGNAL_REG,
+					AS3722_BATTERY_VOLTAGE_MONITOR2_REG),
+	regmap_reg_range(AS3722_SD_CONTROL_REG, AS3722_PWM_VCONTROL4_REG),
+	regmap_reg_range(AS3722_BB_CHARGER_REG, AS3722_SRAM_REG),
+	regmap_reg_range(AS3722_INTERRUPT_MASK1_REG, AS3722_TEMP_STATUS_REG),
+	regmap_reg_range(AS3722_ADC0_CONTROL_REG, AS3722_ADC1_CONTROL_REG),
+	regmap_reg_range(AS3722_ADC1_THRESHOLD_HI_MSB_REG,
+					AS3722_ADC_CONFIGURATION_REG),
+	regmap_reg_range(AS3722_LOCK_REG, AS3722_LOCK_REG),
+};
+
+static const struct regmap_access_table as3722_writable_table = {
+	.yes_ranges = as3722_writable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(as3722_writable_ranges),
+};
+
+static const struct regmap_range as3722_cacheable_ranges[] = {
+	regmap_reg_range(AS3722_SD0_VOLTAGE_REG, AS3722_LDO11_VOLTAGE_REG),
+	regmap_reg_range(AS3722_SD_CONTROL_REG, AS3722_LDOCONTROL1_REG),
+};
+
+static const struct regmap_access_table as3722_volatile_table = {
+	.no_ranges = as3722_cacheable_ranges,
+	.n_no_ranges = ARRAY_SIZE(as3722_cacheable_ranges),
+};
+
+static const struct regmap_config as3722_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = AS3722_MAX_REGISTER,
+	.cache_type = REGCACHE_MAPLE,
+	.rd_table = &as3722_readable_table,
+	.wr_table = &as3722_writable_table,
+	.volatile_table = &as3722_volatile_table,
+};
+
+static int as3722_i2c_of_probe(struct i2c_client *i2c,
+			struct as3722 *as3722)
+{
+	struct device_node *np = i2c->dev.of_node;
+	struct irq_data *irq_data;
+
+	if (!np) {
+		dev_err(&i2c->dev, "Device Tree not found\n");
+		return -EINVAL;
+	}
+
+	irq_data = irq_get_irq_data(i2c->irq);
+	if (!irq_data) {
+		dev_err(&i2c->dev, "Invalid IRQ: %d\n", i2c->irq);
+		return -EINVAL;
+	}
+
+	as3722->en_intern_int_pullup = of_property_read_bool(np,
+					"ams,enable-internal-int-pullup");
+	as3722->en_intern_i2c_pullup = of_property_read_bool(np,
+					"ams,enable-internal-i2c-pullup");
+	as3722->en_ac_ok_pwr_on = of_property_read_bool(np,
+					"ams,enable-ac-ok-power-on");
+	as3722->irq_flags = irqd_get_trigger_type(irq_data);
+	dev_dbg(&i2c->dev, "IRQ flags are 0x%08lx\n", as3722->irq_flags);
+	return 0;
+}
+
+static int as3722_i2c_probe(struct i2c_client *i2c)
+{
+	struct as3722 *as3722;
+	unsigned long irq_flags;
+	int ret;
+	u8 val = 0;
+
+	as3722 = devm_kzalloc(&i2c->dev, sizeof(struct as3722), GFP_KERNEL);
+	if (!as3722)
+		return -ENOMEM;
+
+	as3722->dev = &i2c->dev;
+	as3722->chip_irq = i2c->irq;
+	i2c_set_clientdata(i2c, as3722);
+
+	ret = as3722_i2c_of_probe(i2c, as3722);
+	if (ret < 0)
+		return ret;
+
+	as3722->regmap = devm_regmap_init_i2c(i2c, &as3722_regmap_config);
+	if (IS_ERR(as3722->regmap)) {
+		ret = PTR_ERR(as3722->regmap);
+		dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = as3722_check_device_id(as3722);
+	if (ret < 0)
+		return ret;
+
+	irq_flags = as3722->irq_flags | IRQF_ONESHOT;
+	ret = devm_regmap_add_irq_chip(as3722->dev, as3722->regmap,
+				       as3722->chip_irq,
+				       irq_flags, -1, &as3722_irq_chip,
+				       &as3722->irq_data);
+	if (ret < 0) {
+		dev_err(as3722->dev, "Failed to add regmap irq: %d\n", ret);
+		return ret;
+	}
+
+	ret = as3722_configure_pullups(as3722);
+	if (ret < 0)
+		return ret;
+
+	if (as3722->en_ac_ok_pwr_on)
+		val = AS3722_CTRL_SEQU1_AC_OK_PWR_ON;
+	ret = as3722_update_bits(as3722, AS3722_CTRL_SEQU1_REG,
+			AS3722_CTRL_SEQU1_AC_OK_PWR_ON, val);
+	if (ret < 0) {
+		dev_err(as3722->dev, "CTRLsequ1 update failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_mfd_add_devices(&i2c->dev, -1, as3722_devs,
+				   ARRAY_SIZE(as3722_devs), NULL, 0,
+				   regmap_irq_get_domain(as3722->irq_data));
+	if (ret) {
+		dev_err(as3722->dev, "Failed to add MFD devices: %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_device_init_wakeup(as3722->dev);
+	if (ret)
+		return dev_err_probe(as3722->dev, ret, "Failed to init wakeup\n");
+
+	dev_dbg(as3722->dev, "AS3722 core driver initialized successfully\n");
+	return 0;
+}
+
+static int __maybe_unused as3722_i2c_suspend(struct device *dev)
+{
+	struct as3722 *as3722 = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(as3722->chip_irq);
+	disable_irq(as3722->chip_irq);
+
+	return 0;
+}
+
+static int __maybe_unused as3722_i2c_resume(struct device *dev)
+{
+	struct as3722 *as3722 = dev_get_drvdata(dev);
+
+	enable_irq(as3722->chip_irq);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(as3722->chip_irq);
+
+	return 0;
+}
+
+static const struct of_device_id as3722_of_match[] = {
+	{ .compatible = "ams,as3722", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, as3722_of_match);
+
+static const struct i2c_device_id as3722_i2c_id[] = {
+	{ "as3722" },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, as3722_i2c_id);
+
+static const struct dev_pm_ops as3722_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(as3722_i2c_suspend, as3722_i2c_resume)
+};
+
+static struct i2c_driver as3722_i2c_driver = {
+	.driver = {
+		.name = "as3722",
+		.of_match_table = as3722_of_match,
+		.pm = &as3722_pm_ops,
+	},
+	.probe = as3722_i2c_probe,
+	.id_table = as3722_i2c_id,
+};
+
+module_i2c_driver(as3722_i2c_driver);
+
+MODULE_DESCRIPTION("I2C support for AS3722 PMICs");
+MODULE_AUTHOR("Florian Lobmaier <florian.lobmaier@ams.com>");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
+MODULE_LICENSE("GPL");