From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions 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) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- drivers/mfd/max8997.c | 479 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 479 insertions(+) create mode 100644 drivers/mfd/max8997.c (limited to 'drivers/mfd/max8997.c') diff --git a/drivers/mfd/max8997.c b/drivers/mfd/max8997.c new file mode 100644 index 000000000..7ba8ed1df --- /dev/null +++ b/drivers/mfd/max8997.c @@ -0,0 +1,479 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// max8997.c - mfd core driver for the Maxim 8966 and 8997 +// +// Copyright (C) 2011 Samsung Electronics +// MyungJoo Ham +// +// This driver is based on max8998.c + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define I2C_ADDR_PMIC (0xCC >> 1) +#define I2C_ADDR_MUIC (0x4A >> 1) +#define I2C_ADDR_BATTERY (0x6C >> 1) +#define I2C_ADDR_RTC (0x0C >> 1) +#define I2C_ADDR_HAPTIC (0x90 >> 1) + +static const struct mfd_cell max8997_devs[] = { + { .name = "max8997-pmic", }, + { .name = "max8997-rtc", }, + { .name = "max8997-battery", }, + { .name = "max8997-haptic", }, + { .name = "max8997-muic", }, + { .name = "max8997-led", .id = 1 }, + { .name = "max8997-led", .id = 2 }, +}; + +#ifdef CONFIG_OF +static const struct of_device_id max8997_pmic_dt_match[] = { + { .compatible = "maxim,max8997-pmic", .data = (void *)TYPE_MAX8997 }, + {}, +}; +#endif + +int max8997_read_reg(struct i2c_client *i2c, u8 reg, u8 *dest) +{ + struct max8997_dev *max8997 = i2c_get_clientdata(i2c); + int ret; + + mutex_lock(&max8997->iolock); + ret = i2c_smbus_read_byte_data(i2c, reg); + mutex_unlock(&max8997->iolock); + if (ret < 0) + return ret; + + ret &= 0xff; + *dest = ret; + return 0; +} +EXPORT_SYMBOL_GPL(max8997_read_reg); + +int max8997_bulk_read(struct i2c_client *i2c, u8 reg, int count, u8 *buf) +{ + struct max8997_dev *max8997 = i2c_get_clientdata(i2c); + int ret; + + mutex_lock(&max8997->iolock); + ret = i2c_smbus_read_i2c_block_data(i2c, reg, count, buf); + mutex_unlock(&max8997->iolock); + if (ret < 0) + return ret; + + return 0; +} +EXPORT_SYMBOL_GPL(max8997_bulk_read); + +int max8997_write_reg(struct i2c_client *i2c, u8 reg, u8 value) +{ + struct max8997_dev *max8997 = i2c_get_clientdata(i2c); + int ret; + + mutex_lock(&max8997->iolock); + ret = i2c_smbus_write_byte_data(i2c, reg, value); + mutex_unlock(&max8997->iolock); + return ret; +} +EXPORT_SYMBOL_GPL(max8997_write_reg); + +int max8997_bulk_write(struct i2c_client *i2c, u8 reg, int count, u8 *buf) +{ + struct max8997_dev *max8997 = i2c_get_clientdata(i2c); + int ret; + + mutex_lock(&max8997->iolock); + ret = i2c_smbus_write_i2c_block_data(i2c, reg, count, buf); + mutex_unlock(&max8997->iolock); + if (ret < 0) + return ret; + + return 0; +} +EXPORT_SYMBOL_GPL(max8997_bulk_write); + +int max8997_update_reg(struct i2c_client *i2c, u8 reg, u8 val, u8 mask) +{ + struct max8997_dev *max8997 = i2c_get_clientdata(i2c); + int ret; + + mutex_lock(&max8997->iolock); + ret = i2c_smbus_read_byte_data(i2c, reg); + if (ret >= 0) { + u8 old_val = ret & 0xff; + u8 new_val = (val & mask) | (old_val & (~mask)); + ret = i2c_smbus_write_byte_data(i2c, reg, new_val); + } + mutex_unlock(&max8997->iolock); + return ret; +} +EXPORT_SYMBOL_GPL(max8997_update_reg); + +/* + * Only the common platform data elements for max8997 are parsed here from the + * device tree. Other sub-modules of max8997 such as pmic, rtc and others have + * to parse their own platform data elements from device tree. + * + * The max8997 platform data structure is instantiated here and the drivers for + * the sub-modules need not instantiate another instance while parsing their + * platform data. + */ +static struct max8997_platform_data *max8997_i2c_parse_dt_pdata( + struct device *dev) +{ + struct max8997_platform_data *pd; + + pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL); + if (!pd) + return ERR_PTR(-ENOMEM); + + pd->ono = irq_of_parse_and_map(dev->of_node, 1); + + return pd; +} + +static int max8997_i2c_probe(struct i2c_client *i2c) +{ + struct max8997_dev *max8997; + struct max8997_platform_data *pdata = dev_get_platdata(&i2c->dev); + int ret = 0; + + max8997 = devm_kzalloc(&i2c->dev, sizeof(struct max8997_dev), + GFP_KERNEL); + if (max8997 == NULL) + return -ENOMEM; + + i2c_set_clientdata(i2c, max8997); + max8997->dev = &i2c->dev; + max8997->i2c = i2c; + max8997->type = (uintptr_t)i2c_get_match_data(i2c); + max8997->irq = i2c->irq; + + if (IS_ENABLED(CONFIG_OF) && max8997->dev->of_node) { + pdata = max8997_i2c_parse_dt_pdata(max8997->dev); + if (IS_ERR(pdata)) + return PTR_ERR(pdata); + } + + if (!pdata) + return ret; + + max8997->pdata = pdata; + max8997->ono = pdata->ono; + + mutex_init(&max8997->iolock); + + max8997->rtc = i2c_new_dummy_device(i2c->adapter, I2C_ADDR_RTC); + if (IS_ERR(max8997->rtc)) { + dev_err(max8997->dev, "Failed to allocate I2C device for RTC\n"); + return PTR_ERR(max8997->rtc); + } + i2c_set_clientdata(max8997->rtc, max8997); + + max8997->haptic = i2c_new_dummy_device(i2c->adapter, I2C_ADDR_HAPTIC); + if (IS_ERR(max8997->haptic)) { + dev_err(max8997->dev, "Failed to allocate I2C device for Haptic\n"); + ret = PTR_ERR(max8997->haptic); + goto err_i2c_haptic; + } + i2c_set_clientdata(max8997->haptic, max8997); + + max8997->muic = i2c_new_dummy_device(i2c->adapter, I2C_ADDR_MUIC); + if (IS_ERR(max8997->muic)) { + dev_err(max8997->dev, "Failed to allocate I2C device for MUIC\n"); + ret = PTR_ERR(max8997->muic); + goto err_i2c_muic; + } + i2c_set_clientdata(max8997->muic, max8997); + + pm_runtime_set_active(max8997->dev); + + max8997_irq_init(max8997); + + ret = mfd_add_devices(max8997->dev, -1, max8997_devs, + ARRAY_SIZE(max8997_devs), + NULL, 0, NULL); + if (ret < 0) { + dev_err(max8997->dev, "failed to add MFD devices %d\n", ret); + goto err_mfd; + } + + /* + * TODO: enable others (flash, muic, rtc, battery, ...) and + * check the return value + */ + + /* MAX8997 has a power button input. */ + device_init_wakeup(max8997->dev, true); + + return ret; + +err_mfd: + mfd_remove_devices(max8997->dev); + i2c_unregister_device(max8997->muic); +err_i2c_muic: + i2c_unregister_device(max8997->haptic); +err_i2c_haptic: + i2c_unregister_device(max8997->rtc); + return ret; +} + +static const struct i2c_device_id max8997_i2c_id[] = { + { "max8997", TYPE_MAX8997 }, + { "max8966", TYPE_MAX8966 }, + { } +}; + +static u8 max8997_dumpaddr_pmic[] = { + MAX8997_REG_INT1MSK, + MAX8997_REG_INT2MSK, + MAX8997_REG_INT3MSK, + MAX8997_REG_INT4MSK, + MAX8997_REG_MAINCON1, + MAX8997_REG_MAINCON2, + MAX8997_REG_BUCKRAMP, + MAX8997_REG_BUCK1CTRL, + MAX8997_REG_BUCK1DVS1, + MAX8997_REG_BUCK1DVS2, + MAX8997_REG_BUCK1DVS3, + MAX8997_REG_BUCK1DVS4, + MAX8997_REG_BUCK1DVS5, + MAX8997_REG_BUCK1DVS6, + MAX8997_REG_BUCK1DVS7, + MAX8997_REG_BUCK1DVS8, + MAX8997_REG_BUCK2CTRL, + MAX8997_REG_BUCK2DVS1, + MAX8997_REG_BUCK2DVS2, + MAX8997_REG_BUCK2DVS3, + MAX8997_REG_BUCK2DVS4, + MAX8997_REG_BUCK2DVS5, + MAX8997_REG_BUCK2DVS6, + MAX8997_REG_BUCK2DVS7, + MAX8997_REG_BUCK2DVS8, + MAX8997_REG_BUCK3CTRL, + MAX8997_REG_BUCK3DVS, + MAX8997_REG_BUCK4CTRL, + MAX8997_REG_BUCK4DVS, + MAX8997_REG_BUCK5CTRL, + MAX8997_REG_BUCK5DVS1, + MAX8997_REG_BUCK5DVS2, + MAX8997_REG_BUCK5DVS3, + MAX8997_REG_BUCK5DVS4, + MAX8997_REG_BUCK5DVS5, + MAX8997_REG_BUCK5DVS6, + MAX8997_REG_BUCK5DVS7, + MAX8997_REG_BUCK5DVS8, + MAX8997_REG_BUCK6CTRL, + MAX8997_REG_BUCK6BPSKIPCTRL, + MAX8997_REG_BUCK7CTRL, + MAX8997_REG_BUCK7DVS, + MAX8997_REG_LDO1CTRL, + MAX8997_REG_LDO2CTRL, + MAX8997_REG_LDO3CTRL, + MAX8997_REG_LDO4CTRL, + MAX8997_REG_LDO5CTRL, + MAX8997_REG_LDO6CTRL, + MAX8997_REG_LDO7CTRL, + MAX8997_REG_LDO8CTRL, + MAX8997_REG_LDO9CTRL, + MAX8997_REG_LDO10CTRL, + MAX8997_REG_LDO11CTRL, + MAX8997_REG_LDO12CTRL, + MAX8997_REG_LDO13CTRL, + MAX8997_REG_LDO14CTRL, + MAX8997_REG_LDO15CTRL, + MAX8997_REG_LDO16CTRL, + MAX8997_REG_LDO17CTRL, + MAX8997_REG_LDO18CTRL, + MAX8997_REG_LDO21CTRL, + MAX8997_REG_MBCCTRL1, + MAX8997_REG_MBCCTRL2, + MAX8997_REG_MBCCTRL3, + MAX8997_REG_MBCCTRL4, + MAX8997_REG_MBCCTRL5, + MAX8997_REG_MBCCTRL6, + MAX8997_REG_OTPCGHCVS, + MAX8997_REG_SAFEOUTCTRL, + MAX8997_REG_LBCNFG1, + MAX8997_REG_LBCNFG2, + MAX8997_REG_BBCCTRL, + + MAX8997_REG_FLASH1_CUR, + MAX8997_REG_FLASH2_CUR, + MAX8997_REG_MOVIE_CUR, + MAX8997_REG_GSMB_CUR, + MAX8997_REG_BOOST_CNTL, + MAX8997_REG_LEN_CNTL, + MAX8997_REG_FLASH_CNTL, + MAX8997_REG_WDT_CNTL, + MAX8997_REG_MAXFLASH1, + MAX8997_REG_MAXFLASH2, + MAX8997_REG_FLASHSTATUSMASK, + + MAX8997_REG_GPIOCNTL1, + MAX8997_REG_GPIOCNTL2, + MAX8997_REG_GPIOCNTL3, + MAX8997_REG_GPIOCNTL4, + MAX8997_REG_GPIOCNTL5, + MAX8997_REG_GPIOCNTL6, + MAX8997_REG_GPIOCNTL7, + MAX8997_REG_GPIOCNTL8, + MAX8997_REG_GPIOCNTL9, + MAX8997_REG_GPIOCNTL10, + MAX8997_REG_GPIOCNTL11, + MAX8997_REG_GPIOCNTL12, + + MAX8997_REG_LDO1CONFIG, + MAX8997_REG_LDO2CONFIG, + MAX8997_REG_LDO3CONFIG, + MAX8997_REG_LDO4CONFIG, + MAX8997_REG_LDO5CONFIG, + MAX8997_REG_LDO6CONFIG, + MAX8997_REG_LDO7CONFIG, + MAX8997_REG_LDO8CONFIG, + MAX8997_REG_LDO9CONFIG, + MAX8997_REG_LDO10CONFIG, + MAX8997_REG_LDO11CONFIG, + MAX8997_REG_LDO12CONFIG, + MAX8997_REG_LDO13CONFIG, + MAX8997_REG_LDO14CONFIG, + MAX8997_REG_LDO15CONFIG, + MAX8997_REG_LDO16CONFIG, + MAX8997_REG_LDO17CONFIG, + MAX8997_REG_LDO18CONFIG, + MAX8997_REG_LDO21CONFIG, + + MAX8997_REG_DVSOKTIMER1, + MAX8997_REG_DVSOKTIMER2, + MAX8997_REG_DVSOKTIMER4, + MAX8997_REG_DVSOKTIMER5, +}; + +static u8 max8997_dumpaddr_muic[] = { + MAX8997_MUIC_REG_INTMASK1, + MAX8997_MUIC_REG_INTMASK2, + MAX8997_MUIC_REG_INTMASK3, + MAX8997_MUIC_REG_CDETCTRL, + MAX8997_MUIC_REG_CONTROL1, + MAX8997_MUIC_REG_CONTROL2, + MAX8997_MUIC_REG_CONTROL3, +}; + +static u8 max8997_dumpaddr_haptic[] = { + MAX8997_HAPTIC_REG_CONF1, + MAX8997_HAPTIC_REG_CONF2, + MAX8997_HAPTIC_REG_DRVCONF, + MAX8997_HAPTIC_REG_CYCLECONF1, + MAX8997_HAPTIC_REG_CYCLECONF2, + MAX8997_HAPTIC_REG_SIGCONF1, + MAX8997_HAPTIC_REG_SIGCONF2, + MAX8997_HAPTIC_REG_SIGCONF3, + MAX8997_HAPTIC_REG_SIGCONF4, + MAX8997_HAPTIC_REG_SIGDC1, + MAX8997_HAPTIC_REG_SIGDC2, + MAX8997_HAPTIC_REG_SIGPWMDC1, + MAX8997_HAPTIC_REG_SIGPWMDC2, + MAX8997_HAPTIC_REG_SIGPWMDC3, + MAX8997_HAPTIC_REG_SIGPWMDC4, +}; + +static int max8997_freeze(struct device *dev) +{ + struct i2c_client *i2c = to_i2c_client(dev); + struct max8997_dev *max8997 = i2c_get_clientdata(i2c); + int i; + + for (i = 0; i < ARRAY_SIZE(max8997_dumpaddr_pmic); i++) + max8997_read_reg(i2c, max8997_dumpaddr_pmic[i], + &max8997->reg_dump[i]); + + for (i = 0; i < ARRAY_SIZE(max8997_dumpaddr_muic); i++) + max8997_read_reg(i2c, max8997_dumpaddr_muic[i], + &max8997->reg_dump[i + MAX8997_REG_PMIC_END]); + + for (i = 0; i < ARRAY_SIZE(max8997_dumpaddr_haptic); i++) + max8997_read_reg(i2c, max8997_dumpaddr_haptic[i], + &max8997->reg_dump[i + MAX8997_REG_PMIC_END + + MAX8997_MUIC_REG_END]); + + return 0; +} + +static int max8997_restore(struct device *dev) +{ + struct i2c_client *i2c = to_i2c_client(dev); + struct max8997_dev *max8997 = i2c_get_clientdata(i2c); + int i; + + for (i = 0; i < ARRAY_SIZE(max8997_dumpaddr_pmic); i++) + max8997_write_reg(i2c, max8997_dumpaddr_pmic[i], + max8997->reg_dump[i]); + + for (i = 0; i < ARRAY_SIZE(max8997_dumpaddr_muic); i++) + max8997_write_reg(i2c, max8997_dumpaddr_muic[i], + max8997->reg_dump[i + MAX8997_REG_PMIC_END]); + + for (i = 0; i < ARRAY_SIZE(max8997_dumpaddr_haptic); i++) + max8997_write_reg(i2c, max8997_dumpaddr_haptic[i], + max8997->reg_dump[i + MAX8997_REG_PMIC_END + + MAX8997_MUIC_REG_END]); + + return 0; +} + +static int max8997_suspend(struct device *dev) +{ + struct i2c_client *i2c = to_i2c_client(dev); + struct max8997_dev *max8997 = i2c_get_clientdata(i2c); + + disable_irq(max8997->irq); + if (device_may_wakeup(dev)) + enable_irq_wake(max8997->irq); + return 0; +} + +static int max8997_resume(struct device *dev) +{ + struct i2c_client *i2c = to_i2c_client(dev); + struct max8997_dev *max8997 = i2c_get_clientdata(i2c); + + if (device_may_wakeup(dev)) + disable_irq_wake(max8997->irq); + enable_irq(max8997->irq); + return max8997_irq_resume(max8997); +} + +static const struct dev_pm_ops max8997_pm = { + .suspend = max8997_suspend, + .resume = max8997_resume, + .freeze = max8997_freeze, + .restore = max8997_restore, +}; + +static struct i2c_driver max8997_i2c_driver = { + .driver = { + .name = "max8997", + .pm = &max8997_pm, + .suppress_bind_attrs = true, + .of_match_table = of_match_ptr(max8997_pmic_dt_match), + }, + .probe = max8997_i2c_probe, + .id_table = max8997_i2c_id, +}; + +static int __init max8997_i2c_init(void) +{ + return i2c_add_driver(&max8997_i2c_driver); +} +/* init early so consumer devices can complete system boot */ +subsys_initcall(max8997_i2c_init); -- cgit v1.3.1