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, 405 insertions, 0 deletions

diff --git a/drivers/regulator/88pm8607.c b/drivers/regulator/88pm8607.c
new file mode 100644
index 000000000..969554725
--- /dev/null
+++ b/drivers/regulator/88pm8607.c
@@ -0,0 +1,405 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Regulators driver for Marvell 88PM8607
+ *
+ * Copyright (C) 2009 Marvell International Ltd.
+ *	Haojian Zhuang <haojian.zhuang@marvell.com>
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/mfd/88pm860x.h>
+#include <linux/module.h>
+
+struct pm8607_regulator_info {
+	struct regulator_desc	desc;
+
+	unsigned int	*vol_suspend;
+
+	int	slope_double;
+};
+
+static const unsigned int BUCK1_table[] = {
+	 725000,  750000,  775000,  800000,  825000,  850000,  875000,  900000,
+	 925000,  950000,  975000, 1000000, 1025000, 1050000, 1075000, 1100000,
+	1125000, 1150000, 1175000, 1200000, 1225000, 1250000, 1275000, 1300000,
+	1325000, 1350000, 1375000, 1400000, 1425000, 1450000, 1475000, 1500000,
+	      0,   25000,   50000,   75000,  100000,  125000,  150000,  175000,
+	 200000,  225000,  250000,  275000,  300000,  325000,  350000,  375000,
+	 400000,  425000,  450000,  475000,  500000,  525000,  550000,  575000,
+	 600000,  625000,  650000,  675000,  700000,  725000,  750000,  775000,
+};
+
+static const unsigned int BUCK1_suspend_table[] = {
+	      0,   25000,   50000,   75000,  100000,  125000,  150000,  175000,
+	 200000,  225000,  250000,  275000,  300000,  325000,  350000,  375000,
+	 400000,  425000,  450000,  475000,  500000,  525000,  550000,  575000,
+	 600000,  625000,  650000,  675000,  700000,  725000,  750000,  775000,
+	 800000,  825000,  850000,  875000,  900000,  925000,  950000,  975000,
+	1000000, 1025000, 1050000, 1075000, 1100000, 1125000, 1150000, 1175000,
+	1200000, 1225000, 1250000, 1275000, 1300000, 1325000, 1350000, 1375000,
+	1400000, 1425000, 1450000, 1475000, 1500000, 1500000, 1500000, 1500000,
+};
+
+static const unsigned int BUCK2_table[] = {
+	      0,   50000,  100000,  150000,  200000,  250000,  300000,  350000,
+	 400000,  450000,  500000,  550000,  600000,  650000,  700000,  750000,
+	 800000,  850000,  900000,  950000, 1000000, 1050000, 1100000, 1150000,
+	1200000, 1250000, 1300000, 1350000, 1400000, 1450000, 1500000, 1550000,
+	1600000, 1650000, 1700000, 1750000, 1800000, 1850000, 1900000, 1950000,
+	2000000, 2050000, 2100000, 2150000, 2200000, 2250000, 2300000, 2350000,
+	2400000, 2450000, 2500000, 2550000, 2600000, 2650000, 2700000, 2750000,
+	2800000, 2850000, 2900000, 2950000, 3000000, 3000000, 3000000, 3000000,
+};
+
+static const unsigned int BUCK2_suspend_table[] = {
+	      0,   50000,  100000,  150000,  200000,  250000,  300000,  350000,
+	 400000,  450000,  500000,  550000,  600000,  650000,  700000,  750000,
+	 800000,  850000,  900000,  950000, 1000000, 1050000, 1100000, 1150000,
+	1200000, 1250000, 1300000, 1350000, 1400000, 1450000, 1500000, 1550000,
+	1600000, 1650000, 1700000, 1750000, 1800000, 1850000, 1900000, 1950000,
+	2000000, 2050000, 2100000, 2150000, 2200000, 2250000, 2300000, 2350000,
+	2400000, 2450000, 2500000, 2550000, 2600000, 2650000, 2700000, 2750000,
+	2800000, 2850000, 2900000, 2950000, 3000000, 3000000, 3000000, 3000000,
+};
+
+static const unsigned int BUCK3_table[] = {
+	      0,   25000,   50000,   75000,  100000,  125000,  150000,  175000,
+	 200000,  225000,  250000,  275000,  300000,  325000,  350000,  375000,
+	 400000,  425000,  450000,  475000,  500000,  525000,  550000,  575000,
+	 600000,  625000,  650000,  675000,  700000,  725000,  750000,  775000,
+	 800000,  825000,  850000,  875000,  900000,  925000,  950000,  975000,
+	1000000, 1025000, 1050000, 1075000, 1100000, 1125000, 1150000, 1175000,
+	1200000, 1225000, 1250000, 1275000, 1300000, 1325000, 1350000, 1375000,
+	1400000, 1425000, 1450000, 1475000, 1500000, 1500000, 1500000, 1500000,
+};
+
+static const unsigned int BUCK3_suspend_table[] = {
+	      0,   25000,   50000,   75000,  100000,  125000,  150000,  175000,
+	 200000,  225000,  250000,  275000,  300000,  325000,  350000,  375000,
+	 400000,  425000,  450000,  475000,  500000,  525000,  550000,  575000,
+	 600000,  625000,  650000,  675000,  700000,  725000,  750000,  775000,
+	 800000,  825000,  850000,  875000,  900000,  925000,  950000,  975000,
+	1000000, 1025000, 1050000, 1075000, 1100000, 1125000, 1150000, 1175000,
+	1200000, 1225000, 1250000, 1275000, 1300000, 1325000, 1350000, 1375000,
+	1400000, 1425000, 1450000, 1475000, 1500000, 1500000, 1500000, 1500000,
+};
+
+static const unsigned int LDO1_table[] = {
+	1800000, 1200000, 2800000, 0,
+};
+
+static const unsigned int LDO1_suspend_table[] = {
+	1800000, 1200000, 0, 0,
+};
+
+static const unsigned int LDO2_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2850000, 3300000,
+};
+
+static const unsigned int LDO2_suspend_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2850000, 2900000,
+};
+
+static const unsigned int LDO3_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2850000, 3300000,
+};
+
+static const unsigned int LDO3_suspend_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2850000, 2900000,
+};
+
+static const unsigned int LDO4_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2900000, 3300000,
+};
+
+static const unsigned int LDO4_suspend_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2900000, 2900000,
+};
+
+static const unsigned int LDO5_table[] = {
+	2900000, 3000000, 3100000, 3300000,
+};
+
+static const unsigned int LDO5_suspend_table[] = {
+	2900000, 0, 0, 0,
+};
+
+static const unsigned int LDO6_table[] = {
+	1800000, 1850000, 2600000, 2650000, 2700000, 2750000, 2800000, 3300000,
+};
+
+static const unsigned int LDO6_suspend_table[] = {
+	1800000, 1850000, 2600000, 2650000, 2700000, 2750000, 2800000, 2900000,
+};
+
+static const unsigned int LDO7_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2850000, 2900000,
+};
+
+static const unsigned int LDO7_suspend_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2850000, 2900000,
+};
+
+static const unsigned int LDO8_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2850000, 2900000,
+};
+
+static const unsigned int LDO8_suspend_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2850000, 2900000,
+};
+
+static const unsigned int LDO9_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2850000, 3300000,
+};
+
+static const unsigned int LDO9_suspend_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2850000, 2900000,
+};
+
+static const unsigned int LDO10_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2850000, 3300000,
+	1200000, 1200000, 1200000, 1200000, 1200000, 1200000, 1200000, 1200000,
+};
+
+static const unsigned int LDO10_suspend_table[] = {
+	1800000, 1850000, 1900000, 2700000, 2750000, 2800000, 2850000, 2900000,
+	1200000, 1200000, 1200000, 1200000, 1200000, 1200000, 1200000, 1200000,
+};
+
+static const unsigned int LDO12_table[] = {
+	1800000, 1900000, 2700000, 2800000, 2900000, 3000000, 3100000, 3300000,
+	1200000, 1200000, 1200000, 1200000, 1200000, 1200000, 1200000, 1200000,
+};
+
+static const unsigned int LDO12_suspend_table[] = {
+	1800000, 1900000, 2700000, 2800000, 2900000, 2900000, 2900000, 2900000,
+	1200000, 1200000, 1200000, 1200000, 1200000, 1200000, 1200000, 1200000,
+};
+
+static const unsigned int LDO13_table[] = {
+	1200000, 1300000, 1800000, 2000000, 2500000, 2800000, 3000000, 0,
+};
+
+static const unsigned int LDO13_suspend_table[] = {
+	0,
+};
+
+static const unsigned int LDO14_table[] = {
+	1800000, 1850000, 2700000, 2750000, 2800000, 2850000, 2900000, 3300000,
+};
+
+static const unsigned int LDO14_suspend_table[] = {
+	1800000, 1850000, 2700000, 2750000, 2800000, 2850000, 2900000, 2900000,
+};
+
+static int pm8607_list_voltage(struct regulator_dev *rdev, unsigned index)
+{
+	struct pm8607_regulator_info *info = rdev_get_drvdata(rdev);
+	int ret;
+
+	ret = regulator_list_voltage_table(rdev, index);
+	if (ret < 0)
+		return ret;
+
+	if (info->slope_double)
+		ret <<= 1;
+
+	return ret;
+}
+
+static const struct regulator_ops pm8607_regulator_ops = {
+	.list_voltage	= pm8607_list_voltage,
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.enable = regulator_enable_regmap,
+	.disable = regulator_disable_regmap,
+	.is_enabled = regulator_is_enabled_regmap,
+};
+
+static const struct regulator_ops pm8606_preg_ops = {
+	.enable		= regulator_enable_regmap,
+	.disable	= regulator_disable_regmap,
+	.is_enabled	= regulator_is_enabled_regmap,
+};
+
+#define PM8606_PREG(ereg, ebit)						\
+{									\
+	.desc	= {							\
+		.name	= "PREG",					\
+		.of_match = of_match_ptr("PREG"),			\
+		.regulators_node = of_match_ptr("regulators"),		\
+		.ops	= &pm8606_preg_ops,				\
+		.type	= REGULATOR_CURRENT,				\
+		.id	= PM8606_ID_PREG,				\
+		.owner	= THIS_MODULE,					\
+		.enable_reg = PM8606_##ereg,				\
+		.enable_mask = (ebit),					\
+		.enable_is_inverted = true,				\
+	},								\
+}
+
+#define PM8607_DVC(vreg, ureg, ubit, ereg, ebit)			\
+{									\
+	.desc	= {							\
+		.name	= #vreg,					\
+		.of_match = of_match_ptr(#vreg),			\
+		.regulators_node = of_match_ptr("regulators"),		\
+		.ops	= &pm8607_regulator_ops,			\
+		.type	= REGULATOR_VOLTAGE,				\
+		.id	= PM8607_ID_##vreg,				\
+		.owner	= THIS_MODULE,					\
+		.volt_table = vreg##_table,				\
+		.n_voltages = ARRAY_SIZE(vreg##_table),			\
+		.vsel_reg = PM8607_##vreg,				\
+		.vsel_mask = ARRAY_SIZE(vreg##_table) - 1,		\
+		.apply_reg = PM8607_##ureg,				\
+		.apply_bit = (ubit),					\
+		.enable_reg = PM8607_##ereg,				\
+		.enable_mask = 1 << (ebit),				\
+	},								\
+	.slope_double	= (0),						\
+	.vol_suspend	= (unsigned int *)&vreg##_suspend_table,	\
+}
+
+#define PM8607_LDO(_id, vreg, shift, ereg, ebit)			\
+{									\
+	.desc	= {							\
+		.name	= "LDO" #_id,					\
+		.of_match = of_match_ptr("LDO" #_id),			\
+		.regulators_node = of_match_ptr("regulators"),		\
+		.ops	= &pm8607_regulator_ops,			\
+		.type	= REGULATOR_VOLTAGE,				\
+		.id	= PM8607_ID_LDO##_id,				\
+		.owner	= THIS_MODULE,					\
+		.volt_table = LDO##_id##_table,				\
+		.n_voltages = ARRAY_SIZE(LDO##_id##_table),		\
+		.vsel_reg = PM8607_##vreg,				\
+		.vsel_mask = (ARRAY_SIZE(LDO##_id##_table) - 1) << (shift), \
+		.enable_reg = PM8607_##ereg,				\
+		.enable_mask = 1 << (ebit),				\
+	},								\
+	.slope_double	= (0),						\
+	.vol_suspend	= (unsigned int *)&LDO##_id##_suspend_table,	\
+}
+
+static struct pm8607_regulator_info pm8607_regulator_info[] = {
+	PM8607_DVC(BUCK1, GO, BIT(0), SUPPLIES_EN11, 0),
+	PM8607_DVC(BUCK2, GO, BIT(1), SUPPLIES_EN11, 1),
+	PM8607_DVC(BUCK3, GO, BIT(2), SUPPLIES_EN11, 2),
+
+	PM8607_LDO(1,         LDO1, 0, SUPPLIES_EN11, 3),
+	PM8607_LDO(2,         LDO2, 0, SUPPLIES_EN11, 4),
+	PM8607_LDO(3,         LDO3, 0, SUPPLIES_EN11, 5),
+	PM8607_LDO(4,         LDO4, 0, SUPPLIES_EN11, 6),
+	PM8607_LDO(5,         LDO5, 0, SUPPLIES_EN11, 7),
+	PM8607_LDO(6,         LDO6, 0, SUPPLIES_EN12, 0),
+	PM8607_LDO(7,         LDO7, 0, SUPPLIES_EN12, 1),
+	PM8607_LDO(8,         LDO8, 0, SUPPLIES_EN12, 2),
+	PM8607_LDO(9,         LDO9, 0, SUPPLIES_EN12, 3),
+	PM8607_LDO(10,        LDO10, 0, SUPPLIES_EN12, 4),
+	PM8607_LDO(12,        LDO12, 0, SUPPLIES_EN12, 5),
+	PM8607_LDO(13, VIBRATOR_SET, 1, VIBRATOR_SET, 0),
+	PM8607_LDO(14,        LDO14, 0, SUPPLIES_EN12, 6),
+};
+
+static struct pm8607_regulator_info pm8606_regulator_info[] = {
+	PM8606_PREG(PREREGULATORB, 5),
+};
+
+static int pm8607_regulator_probe(struct platform_device *pdev)
+{
+	struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
+	struct pm8607_regulator_info *info = NULL;
+	struct regulator_init_data *pdata = dev_get_platdata(&pdev->dev);
+	struct regulator_config config = { };
+	struct regulator_dev *rdev;
+	struct resource *res;
+	int i;
+
+	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
+	if (res) {
+		/* There're resources in 88PM8607 regulator driver */
+		for (i = 0; i < ARRAY_SIZE(pm8607_regulator_info); i++) {
+			info = &pm8607_regulator_info[i];
+			if (info->desc.vsel_reg == res->start)
+				break;
+		}
+		if (i == ARRAY_SIZE(pm8607_regulator_info)) {
+			dev_err(&pdev->dev, "Failed to find regulator %llu\n",
+				(unsigned long long)res->start);
+			return -EINVAL;
+		}
+	} else {
+		/* There's no resource in 88PM8606 PREG regulator driver */
+		info = &pm8606_regulator_info[0];
+		/* i is used to check regulator ID */
+		i = -1;
+	}
+
+	/* check DVC ramp slope double */
+	if ((i == PM8607_ID_BUCK3) && chip->buck3_double)
+		info->slope_double = 1;
+
+	config.dev = chip->dev;
+	config.driver_data = info;
+
+	if (pdata)
+		config.init_data = pdata;
+
+	if (chip->id == CHIP_PM8607)
+		config.regmap = chip->regmap;
+	else
+		config.regmap = chip->regmap_companion;
+
+	rdev = devm_regulator_register(&pdev->dev, &info->desc, &config);
+	if (IS_ERR(rdev)) {
+		dev_err(&pdev->dev, "failed to register regulator %s\n",
+			info->desc.name);
+		return PTR_ERR(rdev);
+	}
+
+	platform_set_drvdata(pdev, info);
+	return 0;
+}
+
+static const struct platform_device_id pm8607_regulator_driver_ids[] = {
+	{
+		.name	= "88pm860x-regulator",
+	}, {
+		.name	= "88pm860x-preg",
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, pm8607_regulator_driver_ids);
+
+static struct platform_driver pm8607_regulator_driver = {
+	.driver		= {
+		.name	= "88pm860x-regulator",
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+	.probe		= pm8607_regulator_probe,
+	.id_table	= pm8607_regulator_driver_ids,
+};
+
+static int __init pm8607_regulator_init(void)
+{
+	return platform_driver_register(&pm8607_regulator_driver);
+}
+subsys_initcall(pm8607_regulator_init);
+
+static void __exit pm8607_regulator_exit(void)
+{
+	platform_driver_unregister(&pm8607_regulator_driver);
+}
+module_exit(pm8607_regulator_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
+MODULE_DESCRIPTION("Regulator Driver for Marvell 88PM8607 PMIC");
+MODULE_ALIAS("platform:88pm8607-regulator");