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/i3c/device.c | 352 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 352 insertions(+) create mode 100644 drivers/i3c/device.c (limited to 'drivers/i3c/device.c') diff --git a/drivers/i3c/device.c b/drivers/i3c/device.c new file mode 100644 index 000000000..f1ba363b2 --- /dev/null +++ b/drivers/i3c/device.c @@ -0,0 +1,352 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018 Cadence Design Systems Inc. + * + * Author: Boris Brezillon + */ + +#include +#include +#include +#include +#include +#include + +#include "internals.h" + +/** + * i3c_device_do_xfers() - do I3C transfers directed to a specific device + * + * @dev: device with which the transfers should be done + * @xfers: array of transfers + * @nxfers: number of transfers + * @mode: transfer mode + * + * Initiate one or several private SDR transfers with @dev. + * + * This function can sleep and thus cannot be called in atomic context. + * + * Return: + * * 0 in case of success, a negative error core otherwise. + * * -EAGAIN: controller lost address arbitration. Target (IBI, HJ or + * controller role request) win the bus. Client driver needs to resend the + * 'xfers' some time later. See I3C spec ver 1.1.1 09-Jun-2021. Section: + * 5.1.2.2.3. + */ +int i3c_device_do_xfers(struct i3c_device *dev, struct i3c_xfer *xfers, + int nxfers, enum i3c_xfer_mode mode) +{ + int ret, i; + + if (nxfers < 1) + return 0; + + for (i = 0; i < nxfers; i++) { + if (!xfers[i].len || !xfers[i].data.in) + return -EINVAL; + } + + ret = i3c_bus_rpm_get(dev->bus); + if (ret) + return ret; + + i3c_bus_normaluse_lock(dev->bus); + ret = i3c_dev_do_xfers_locked(dev->desc, xfers, nxfers, mode); + i3c_bus_normaluse_unlock(dev->bus); + + i3c_bus_rpm_put(dev->bus); + + return ret; +} +EXPORT_SYMBOL_GPL(i3c_device_do_xfers); + +/** + * i3c_device_do_setdasa() - do I3C dynamic address assignement with + * static address + * + * @dev: device with which the DAA should be done + * + * Return: 0 in case of success, a negative error core otherwise. + */ +int i3c_device_do_setdasa(struct i3c_device *dev) +{ + int ret; + + ret = i3c_bus_rpm_get(dev->bus); + if (ret) + return ret; + + i3c_bus_normaluse_lock(dev->bus); + ret = i3c_dev_setdasa_locked(dev->desc); + i3c_bus_normaluse_unlock(dev->bus); + + i3c_bus_rpm_put(dev->bus); + + return ret; +} +EXPORT_SYMBOL_GPL(i3c_device_do_setdasa); + +/** + * i3c_device_get_info() - get I3C device information + * + * @dev: device we want information on + * @info: the information object to fill in + * + * Retrieve I3C dev info. + */ +void i3c_device_get_info(const struct i3c_device *dev, + struct i3c_device_info *info) +{ + if (!info) + return; + + i3c_bus_normaluse_lock(dev->bus); + *info = dev->desc->info; + i3c_bus_normaluse_unlock(dev->bus); +} +EXPORT_SYMBOL_GPL(i3c_device_get_info); + +/** + * i3c_device_disable_ibi() - Disable IBIs coming from a specific device + * @dev: device on which IBIs should be disabled + * + * This function disable IBIs coming from a specific device and wait for + * all pending IBIs to be processed. + * + * Return: 0 in case of success, a negative error core otherwise. + */ +int i3c_device_disable_ibi(struct i3c_device *dev) +{ + int ret; + + if (i3c_bus_rpm_ibi_allowed(dev->bus)) { + ret = i3c_bus_rpm_get(dev->bus); + if (ret) + return ret; + } + + i3c_bus_normaluse_lock(dev->bus); + if (dev->desc) { + mutex_lock(&dev->desc->ibi_lock); + ret = i3c_dev_disable_ibi_locked(dev->desc); + mutex_unlock(&dev->desc->ibi_lock); + } else { + ret = -ENOENT; + } + i3c_bus_normaluse_unlock(dev->bus); + + if (!ret || i3c_bus_rpm_ibi_allowed(dev->bus)) + i3c_bus_rpm_put(dev->bus); + + return ret; +} +EXPORT_SYMBOL_GPL(i3c_device_disable_ibi); + +/** + * i3c_device_enable_ibi() - Enable IBIs coming from a specific device + * @dev: device on which IBIs should be enabled + * + * This function enable IBIs coming from a specific device and wait for + * all pending IBIs to be processed. This should be called on a device + * where i3c_device_request_ibi() has succeeded. + * + * Note that IBIs from this device might be received before this function + * returns to its caller. + * + * Return: 0 in case of success, a negative error core otherwise. + */ +int i3c_device_enable_ibi(struct i3c_device *dev) +{ + int ret; + + ret = i3c_bus_rpm_get(dev->bus); + if (ret) + return ret; + + i3c_bus_normaluse_lock(dev->bus); + if (dev->desc) { + mutex_lock(&dev->desc->ibi_lock); + ret = i3c_dev_enable_ibi_locked(dev->desc); + mutex_unlock(&dev->desc->ibi_lock); + } else { + ret = -ENOENT; + } + i3c_bus_normaluse_unlock(dev->bus); + + if (ret || i3c_bus_rpm_ibi_allowed(dev->bus)) + i3c_bus_rpm_put(dev->bus); + + return ret; +} +EXPORT_SYMBOL_GPL(i3c_device_enable_ibi); + +/** + * i3c_device_request_ibi() - Request an IBI + * @dev: device for which we should enable IBIs + * @req: setup requested for this IBI + * + * This function is responsible for pre-allocating all resources needed to + * process IBIs coming from @dev. When this function returns, the IBI is not + * enabled until i3c_device_enable_ibi() is called. + * + * Return: 0 in case of success, a negative error core otherwise. + */ +int i3c_device_request_ibi(struct i3c_device *dev, + const struct i3c_ibi_setup *req) +{ + int ret; + + if (!req->handler || !req->num_slots) + return -EINVAL; + + ret = i3c_bus_rpm_get(dev->bus); + if (ret) + return ret; + + i3c_bus_normaluse_lock(dev->bus); + if (!dev->desc) { + ret = -ENOENT; + } else if (!(dev->desc->info.bcr & I3C_BCR_IBI_REQ_CAP)) { + ret = -EOPNOTSUPP; + } else { + mutex_lock(&dev->desc->ibi_lock); + ret = i3c_dev_request_ibi_locked(dev->desc, req); + mutex_unlock(&dev->desc->ibi_lock); + } + i3c_bus_normaluse_unlock(dev->bus); + + i3c_bus_rpm_put(dev->bus); + + return ret; +} +EXPORT_SYMBOL_GPL(i3c_device_request_ibi); + +/** + * i3c_device_free_ibi() - Free all resources needed for IBI handling + * @dev: device on which you want to release IBI resources + * + * This function is responsible for de-allocating resources previously + * allocated by i3c_device_request_ibi(). It should be called after disabling + * IBIs with i3c_device_disable_ibi(). + */ +void i3c_device_free_ibi(struct i3c_device *dev) +{ + i3c_bus_normaluse_lock(dev->bus); + if (dev->desc) { + mutex_lock(&dev->desc->ibi_lock); + i3c_dev_free_ibi_locked(dev->desc); + mutex_unlock(&dev->desc->ibi_lock); + } + i3c_bus_normaluse_unlock(dev->bus); +} +EXPORT_SYMBOL_GPL(i3c_device_free_ibi); + +/** + * i3cdev_to_dev() - Returns the device embedded in @i3cdev + * @i3cdev: I3C device + * + * Return: a pointer to a device object. + */ +struct device *i3cdev_to_dev(struct i3c_device *i3cdev) +{ + return &i3cdev->dev; +} +EXPORT_SYMBOL_GPL(i3cdev_to_dev); + +/** + * i3c_device_match_id() - Returns the i3c_device_id entry matching @i3cdev + * @i3cdev: I3C device + * @id_table: I3C device match table + * + * Return: a pointer to an i3c_device_id object or NULL if there's no match. + */ +const struct i3c_device_id * +i3c_device_match_id(struct i3c_device *i3cdev, + const struct i3c_device_id *id_table) +{ + struct i3c_device_info devinfo; + const struct i3c_device_id *id; + u16 manuf, part, ext_info; + bool rndpid; + + i3c_device_get_info(i3cdev, &devinfo); + + manuf = I3C_PID_MANUF_ID(devinfo.pid); + part = I3C_PID_PART_ID(devinfo.pid); + ext_info = I3C_PID_EXTRA_INFO(devinfo.pid); + rndpid = I3C_PID_RND_LOWER_32BITS(devinfo.pid); + + for (id = id_table; id->match_flags != 0; id++) { + if ((id->match_flags & I3C_MATCH_DCR) && + id->dcr != devinfo.dcr) + continue; + + if ((id->match_flags & I3C_MATCH_MANUF) && + id->manuf_id != manuf) + continue; + + if ((id->match_flags & I3C_MATCH_PART) && + (rndpid || id->part_id != part)) + continue; + + if ((id->match_flags & I3C_MATCH_EXTRA_INFO) && + (rndpid || id->extra_info != ext_info)) + continue; + + return id; + } + + return NULL; +} +EXPORT_SYMBOL_GPL(i3c_device_match_id); + +/** + * i3c_device_get_supported_xfer_mode - Returns the supported transfer mode by + * connected master controller. + * @dev: I3C device + * + * Return: a bit mask, which supported transfer mode, bit position is defined at + * enum i3c_hdr_mode + */ +u32 i3c_device_get_supported_xfer_mode(struct i3c_device *dev) +{ + return i3c_bus_to_i3c_master(dev->bus)->this->info.hdr_cap | BIT(I3C_SDR); +} +EXPORT_SYMBOL_GPL(i3c_device_get_supported_xfer_mode); + +/** + * i3c_driver_register_with_owner() - register an I3C device driver + * + * @drv: driver to register + * @owner: module that owns this driver + * + * Register @drv to the core. + * + * Return: 0 in case of success, a negative error core otherwise. + */ +int i3c_driver_register_with_owner(struct i3c_driver *drv, struct module *owner) +{ + drv->driver.owner = owner; + drv->driver.bus = &i3c_bus_type; + + if (!drv->probe) { + pr_err("Trying to register an i3c driver without probe callback\n"); + return -EINVAL; + } + + return driver_register(&drv->driver); +} +EXPORT_SYMBOL_GPL(i3c_driver_register_with_owner); + +/** + * i3c_driver_unregister() - unregister an I3C device driver + * + * @drv: driver to unregister + * + * Unregister @drv. + */ +void i3c_driver_unregister(struct i3c_driver *drv) +{ + driver_unregister(&drv->driver); +} +EXPORT_SYMBOL_GPL(i3c_driver_unregister); -- cgit v1.3.1