hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7ZBQB
----------------------------------
This adds the CPU-inspect infrastructure. CPU-inspect is designed to provide a framework for early detection of SDC by proactively executing CPU inspection test cases.
Silent Data Corruption (SDC), sometimes referred to as Silent Data Error (SDE), is an industry-wide issue impacting not only long-protected memory, storage, and networking, but also computer CPUs. As with software issues, hardware-induced SDC can contribute to data loss and corruption. An SDC occurs when an impacted CPU inadvertently causes errors in the data it processes. For example, an impacted CPU might miscalculate data (i.e., 1+1=3). There may be no indication of these computational errors unless the software systematically checks for errors [1].
SDC issues have been around for many years, but as chips have become more advanced and compact in size, the transistors and lines have become so tiny that small electrical fluctuations can cause errors. Most of these errors are caused by defects during manufacturing and are screened out by the vendors; others are caught by hardware error detection or correction. However, some errors go undetected by hardware; therefore only detection software can protect against such errors [1].
[1] https://support.google.com/cloud/answer/10759085
To use CPU-inspect, you need to load at least one inspector (the driver that specifically executes the CPU inspection code)
Here is an example using CPU-inspect:
# Set the cpumask of CPU-inspect to 10-20 echo 10-20 > /sys/devices/system/cpu/cpuinspect/cpumask # set the max cpu utility of inspectiono threads to 50% echo 50 > /sys/devices/system/cpu/cpuinspect/cpu_utility # start the CPU inspection task echo 1 > /sys/devices/system/cpu/cpuinspect/start_patrol # Check the result to see if some faulty cpu are found cat /sys/devices/system/cpu/cpuinspect/result
In addition to being readable, the 'result' file in cpuinspect can also be polled. The user that use poll() to monitor 'result' will return when a faulty CPU is found or the inspection task is completed.
Signed-off-by: Yu Liao liaoyu15@huawei.com --- drivers/Kconfig | 2 + drivers/Makefile | 1 + drivers/cpuinspect/Kconfig | 13 ++ drivers/cpuinspect/Makefile | 7 + drivers/cpuinspect/cpuinspect.c | 165 ++++++++++++++++++++ drivers/cpuinspect/cpuinspect.h | 46 ++++++ drivers/cpuinspect/inspector.c | 124 +++++++++++++++ drivers/cpuinspect/sysfs.c | 257 ++++++++++++++++++++++++++++++++ include/linux/cpuinspect.h | 40 +++++ 9 files changed, 655 insertions(+) create mode 100644 drivers/cpuinspect/Kconfig create mode 100644 drivers/cpuinspect/Makefile create mode 100644 drivers/cpuinspect/cpuinspect.c create mode 100644 drivers/cpuinspect/cpuinspect.h create mode 100644 drivers/cpuinspect/inspector.c create mode 100644 drivers/cpuinspect/sysfs.c create mode 100644 include/linux/cpuinspect.h
diff --git a/drivers/Kconfig b/drivers/Kconfig index 9f339bed6847..f765c3a688b6 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -242,4 +242,6 @@ source "drivers/roh/Kconfig"
source "drivers/ub/Kconfig"
+source "drivers/cpuinspect/Kconfig" + endmenu diff --git a/drivers/Makefile b/drivers/Makefile index c9b8abae0349..aeeceb66fd2f 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -128,6 +128,7 @@ obj-$(CONFIG_EISA) += eisa/ obj-$(CONFIG_PM_OPP) += opp/ obj-$(CONFIG_CPU_FREQ) += cpufreq/ obj-$(CONFIG_CPU_IDLE) += cpuidle/ +obj-$(CONFIG_CPU_INSPECT) += cpuinspect/ obj-y += mmc/ obj-$(CONFIG_MEMSTICK) += memstick/ obj-$(CONFIG_NEW_LEDS) += leds/ diff --git a/drivers/cpuinspect/Kconfig b/drivers/cpuinspect/Kconfig new file mode 100644 index 000000000000..548412ba3578 --- /dev/null +++ b/drivers/cpuinspect/Kconfig @@ -0,0 +1,13 @@ +# SPDX-License-Identifier: GPL-2.0-only +menu "CPU Inspect" + +config CPU_INSPECT + tristate "CPU inspect support" + depends on SYSFS && 64BIT + default n + help + CPU-inspect is designed to provide a framework for early detection + of SDC by proactively executing CPU inspection test cases. It + includes modular inspector that can be swapped during runtime. + +endmenu diff --git a/drivers/cpuinspect/Makefile b/drivers/cpuinspect/Makefile new file mode 100644 index 000000000000..5634354e57e3 --- /dev/null +++ b/drivers/cpuinspect/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for cpuinspect. +# +ccflags-y = -DDEBUG +obj-$(CONFIG_CPU_INSPECT) += cpu_inspect.o +cpu_inspect-y = cpuinspect.o inspector.o sysfs.o diff --git a/drivers/cpuinspect/cpuinspect.c b/drivers/cpuinspect/cpuinspect.c new file mode 100644 index 000000000000..08b6f05b3ace --- /dev/null +++ b/drivers/cpuinspect/cpuinspect.c @@ -0,0 +1,165 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * cpuinspect.c - core cpuinspect infrastructure + * + * Copyright (c) Huawei Technologies Co., Ltd. 2022-2023. All rights reserved. + * + * Author: Yu Liao liaoyu15@huawei.com + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#include <linux/kernel.h> +#include <linux/mutex.h> +#include <linux/cpu.h> +#include <linux/cpuinspect.h> +#include <linux/module.h> +#include <linux/kthread.h> +#include <linux/delay.h> +#include <linux/atomic.h> + +#include "cpuinspect.h" + +/* + * The core struct, store the most relevant data for cpuinspect. + */ +struct cpuinspect ci_core = { + .inspect_times = 1, + .cpu_utility = 90, +}; + +static struct task_struct *cpuinspect_threads[NR_CPUS]; +static atomic_t active_threads_num; +DECLARE_BITMAP(result, NR_CPUS); +DEFINE_MUTEX(cpuinspect_lock); + +/* inspection thread function */ +static int run_inspector(void *data) +{ + unsigned int cpu = (unsigned int)(unsigned long)data; + unsigned int inspect_times = 0, group, sleep_us, ret; + ktime_t start_time, duration; + + while (!kthread_should_stop()) { + if (inspect_times >= ci_core.inspect_times) + break; + + for (group = 0; group < curr_cpu_inspector->group_num; group++) { + start_time = ktime_get(); + ret = curr_cpu_inspector->start_inspect(group); + if (ret) { + set_bit(cpu, result); + cpuinspect_result_notify(); + } + + /* + * Sleep for a while if user set desired cpu utility. + */ + duration = ktime_get() - start_time; + sleep_us = (duration * 100 / ci_core.cpu_utility - duration) / 1000; + /* + * Since usleep_range is built on top of hrtimers, + * and we don't want to introduce a large number of + * undesired interrupts, choose a range of 1000us + * to balance performance and latency. This can + * cause inspection threads cpu utility is lower + * than required cpu utility. And this also prevents + * soft lockup. + */ + usleep_range(sleep_us, sleep_us + 1000); + + } + inspect_times++; + } + + cpuinspect_threads[cpu] = NULL; + + /* + * When this condition is met, it indicate this is the final cpuinspect + * thread, mark inspect state as 0 and notify user that it has been + * completed. + */ + if (atomic_dec_and_test(&active_threads_num)) { + ci_core.inspect_on = 0; + cpuinspect_result_notify(); + } + + return 0; +} + +int start_inspect_threads(void) +{ + unsigned int cpu = 0; + + bitmap_zero(result, NR_CPUS); + + ci_core.inspect_on = 1; + for_each_cpu(cpu, &ci_core.inspect_cpumask) { + cpuinspect_threads[cpu] = kthread_create_on_node(run_inspector, + (unsigned long *)(unsigned long)cpu, + cpu_to_node(cpu), "cpuinspect/%u", cpu); + if (IS_ERR(cpuinspect_threads[cpu])) { + cpuinspect_threads[cpu] = NULL; + continue; + } + + kthread_bind(cpuinspect_threads[cpu], cpu); + wake_up_process(cpuinspect_threads[cpu]); + atomic_inc(&active_threads_num); + } + + /* + * If creating inspection threads for all CPUs in mask fails (or + * inspect_cpumask is empty), notify user, mark the inspection status + * as 0 and simply exit. + */ + if (unlikely(!atomic_read(&active_threads_num))) { + ci_core.inspect_on = 0; + cpuinspect_result_notify(); + } + + return 0; +} + +int stop_inspect_threads(void) +{ + unsigned int cpu = 0; + + /* All inspection threads has been stopped */ + if (atomic_read(&active_threads_num) == 0) + return 0; + + for_each_cpu(cpu, &ci_core.inspect_cpumask) { + if (cpuinspect_threads[cpu]) + kthread_stop(cpuinspect_threads[cpu]); + } + + return 0; +} + +/** + * cpuinspect_init - core initializer + */ +static int __init cpuinspect_init(void) +{ + cpumask_copy(&ci_core.inspect_cpumask, cpu_all_mask); + + return cpuinspect_add_interface(cpu_subsys.dev_root); +} + +static void __exit cpuinspect_exit(void) +{ + return cpuinspect_remove_interface(cpu_subsys.dev_root); +} + +module_init(cpuinspect_init); +module_exit(cpuinspect_exit); +module_param_string(inspector, param_inspector, CPUINSPECT_NAME_LEN, 0444); +MODULE_LICENSE("GPL"); diff --git a/drivers/cpuinspect/cpuinspect.h b/drivers/cpuinspect/cpuinspect.h new file mode 100644 index 000000000000..9a336d396a16 --- /dev/null +++ b/drivers/cpuinspect/cpuinspect.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * cpuinspect.h - The internal header file + */ + +#ifndef __DRIVER_CPUINSPECT_H +#define __DRIVER_CPUINSPECT_H + +#define CPUINSPECT_NAME_LEN 16 + +/* sysfs */ +int cpuinspect_add_interface(struct device *dev); +void cpuinspect_remove_interface(struct device *dev); +void cpuinspect_result_notify(void); + +/* inspect control */ +int start_inspect_threads(void); +int stop_inspect_threads(void); +int cpuinspect_is_running(void); + +/* switch inspector */ +int cpuinspect_switch_inspector(struct cpu_inspector *insp); + +/* for internal use only */ +extern DECLARE_BITMAP(result, NR_CPUS); +extern struct cpu_inspector *curr_cpu_inspector; +extern struct mutex cpuinspect_lock; +extern struct cpuinspect ci_core; +extern struct list_head cpu_inspectors; +extern char param_inspector[]; + +/** + * struct cpuinspect - the basic cpuinspect structure + * @cpu_utility: Maximum CPU utilization occupied by the inspection thread. + * @inspect_times: The number of times the inspection code will be executed. + * @inspect_cpumask: cpumask to indicate for which CPUs are involved in inspection. + * @inspect_on: Set if the inspection thread is running. + */ +struct cpuinspect { + unsigned int cpu_utility; + unsigned long inspect_times; + int inspect_on; + cpumask_t inspect_cpumask; +}; + +#endif /* __DRIVER_CPUINSPECT_H */ diff --git a/drivers/cpuinspect/inspector.c b/drivers/cpuinspect/inspector.c new file mode 100644 index 000000000000..6cb3cacbbbdb --- /dev/null +++ b/drivers/cpuinspect/inspector.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * inspector.c - inspector support + * + * Copyright (c) Huawei Technologies Co., Ltd. 2022-2023. All rights reserved. + * + * Author: Yu Liao liaoyu15@huawei.com + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#define pr_fmt(fmt) "CPUINSPECT: " fmt + +#include <linux/cpu.h> +#include <linux/cpuinspect.h> +#include <linux/mutex.h> +#include <linux/module.h> +#include <linux/pm_qos.h> + +#include "cpuinspect.h" + + +char param_inspector[CPUINSPECT_NAME_LEN]; + +LIST_HEAD(cpu_inspectors); +struct cpu_inspector *curr_cpu_inspector; +struct cpu_inspector *prev_cpu_inspector; + +/** + * cpuinspect_find_inspector - finds a inspector of the specified name + * @str: the name + */ +static struct cpu_inspector *cpuinspect_find_inspector(const char *str) +{ + struct cpu_inspector *insp; + + list_for_each_entry(insp, &cpu_inspectors, list) + if (!strncasecmp(str, insp->name, CPUINSPECT_NAME_LEN)) + return insp; + return NULL; +} + +/** + * cpuinspect_switch_inspector - changes the inspector + * @insp: the new target inspector + */ +int cpuinspect_switch_inspector(struct cpu_inspector *insp) +{ + if (!insp) + return -EINVAL; + + if (insp == curr_cpu_inspector) + return 0; + + curr_cpu_inspector = insp; + pr_info("using inspector %s, group_num: %u\n", insp->name, insp->group_num); + + return 0; +} + +/** + * cpuinspect_register_inspector - registers a inspector + * @insp: the inspector + */ +int cpuinspect_register_inspector(struct cpu_inspector *insp) +{ + int ret = -EEXIST; + + if (!insp) + return -EINVAL; + + mutex_lock(&cpuinspect_lock); + if (cpuinspect_find_inspector(insp->name) == NULL) { + ret = 0; + list_add_tail(&insp->list, &cpu_inspectors); + + /* + * We select the inspector if current inspector is NULL or it is + * one specificed by kernel parameter. + */ + if (!curr_cpu_inspector || + !strncasecmp(param_inspector, insp->name, CPUINSPECT_NAME_LEN)) + cpuinspect_switch_inspector(insp); + } + mutex_unlock(&cpuinspect_lock); + + return ret; +} +EXPORT_SYMBOL(cpuinspect_register_inspector); + +/** + * cpuinspect_unregister_inspector - unregisters a inspector + * @insp: the inspector + */ +int cpuinspect_unregister_inspector(struct cpu_inspector *insp) +{ + if (!insp) + return -EINVAL; + + mutex_lock(&cpuinspect_lock); + if (curr_cpu_inspector == insp) { + if (ci_core.inspect_on) { + mutex_unlock(&cpuinspect_lock); + return -EBUSY; + } + + curr_cpu_inspector = NULL; + } + + if (!list_empty(&insp->list)) + list_del(&insp->list); + + mutex_unlock(&cpuinspect_lock); + + return 0; +} +EXPORT_SYMBOL(cpuinspect_unregister_inspector); diff --git a/drivers/cpuinspect/sysfs.c b/drivers/cpuinspect/sysfs.c new file mode 100644 index 000000000000..600eab00aa36 --- /dev/null +++ b/drivers/cpuinspect/sysfs.c @@ -0,0 +1,257 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * sysfs.c - sysfs support + * + * Copyright (c) Huawei Technologies Co., Ltd. 2022-2023. All rights reserved. + * + * Author: Yu Liao liaoyu15@huawei.com + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#include <linux/kernel.h> +#include <linux/cpuinspect.h> +#include <linux/sysfs.h> +#include <linux/slab.h> +#include <linux/cpu.h> +#include <linux/completion.h> +#include <linux/capability.h> +#include <linux/device.h> +#include <linux/kobject.h> +#include <linux/printk.h> +#include <linux/bitmap.h> + +#include "cpuinspect.h" + +static ssize_t available_inspector_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct cpu_inspector *tmp; + ssize_t i = 0; + + list_for_each_entry(tmp, &cpu_inspectors, list) { + if (i >= (ssize_t) (PAGE_SIZE - (CPUINSPECT_NAME_LEN + 2))) + goto out; + + i += scnprintf(&buf[i], CPUINSPECT_NAME_LEN + 1, "%s ", tmp->name); + } + +out: + i += sprintf(&buf[i], "\n"); + return i; +} + +static ssize_t current_inspector_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + ssize_t ret; + + if (curr_cpu_inspector) + ret = sprintf(buf, "%s\n", curr_cpu_inspector->name); + else + ret = sprintf(buf, "none\n"); + + return ret; +} + +static ssize_t current_inspector_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + char insp_name[CPUINSPECT_NAME_LEN + 1]; + int ret; + struct cpu_inspector *insp; + + ret = sscanf(buf, "%" __stringify(CPUINSPECT_NAME_LEN) "s", insp_name); + if (ret != 1) + return -EINVAL; + + if (ci_core.inspect_on) + return -EBUSY; + + ret = -EINVAL; + list_for_each_entry(insp, &cpu_inspectors, list) { + if (!strncmp(insp->name, insp_name, CPUINSPECT_NAME_LEN)) { + ret = cpuinspect_switch_inspector(insp); + break; + } + } + + return ret ? ret : count; +} + +ssize_t patrol_complete_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", !ci_core.inspect_on); +} + +ssize_t cpu_utility_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%u\n", ci_core.cpu_utility); +} + +ssize_t cpu_utility_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + unsigned int cpu_util; + + if (kstrtouint(buf, 10, &cpu_util) || cpu_util < 1 || cpu_util > 100) + return -EINVAL; + + ci_core.cpu_utility = cpu_util; + + return size; +} + +ssize_t patrol_times_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%lu\n", ci_core.inspect_times); +} + +ssize_t patrol_times_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + /* + * It is not allowed to modify patrol times during the CPU + * inspection operation. + */ + if (ci_core.inspect_on) + return -EBUSY; + + if (kstrtoul(buf, 10, &ci_core.inspect_times)) + return -EINVAL; + + return size; +} +ssize_t start_patrol_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + bool start_patrol = false; + + if (strtobool(buf, &start_patrol) < 0) + return -EINVAL; + + if (!mutex_trylock(&cpuinspect_lock)) + return -EBUSY; + + /* + * It is not allowed to start the inspection again during the + * inspection process. + */ + if (start_patrol && (int) start_patrol == ci_core.inspect_on) { + mutex_unlock(&cpuinspect_lock); + return -EBUSY; + } + + if (start_patrol == 0) + stop_inspect_threads(); + else if (curr_cpu_inspector) + start_inspect_threads(); + + mutex_unlock(&cpuinspect_lock); + return size; +} + +static ssize_t result_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%*pbl\n", nr_cpu_ids, &result); +} + +static ssize_t cpumask_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%*pbl\n", + cpumask_pr_args(&ci_core.inspect_cpumask)); +} + +static ssize_t cpumask_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + ssize_t err; + + /* + * It is not allowed to modify cpumask during the CPU + * inspection operation. + */ + if (ci_core.inspect_on) + return -EBUSY; + + err = cpulist_parse(buf, &ci_core.inspect_cpumask); + if (err) + return err; + + return count; +} + +/* + * Tell userspace to handle result if one of the following conditions is met: + * - Found fault core + * - Inspection task completed + */ +void cpuinspect_result_notify(void) +{ + sysfs_notify(&cpu_subsys.dev_root->kobj, "cpuinspect", "result"); +} + +static DEVICE_ATTR_RO(result); +static DEVICE_ATTR_WO(start_patrol); +static DEVICE_ATTR_RO(patrol_complete); +static DEVICE_ATTR_RW(cpu_utility); +static DEVICE_ATTR_RW(cpumask); +static DEVICE_ATTR_RW(patrol_times); + +/* show and switch inspector */ +static DEVICE_ATTR_RO(available_inspector); +static DEVICE_ATTR_RW(current_inspector); + + +static struct attribute *cpuinspect_attrs[] = { + &dev_attr_result.attr, + &dev_attr_start_patrol.attr, + &dev_attr_patrol_complete.attr, + &dev_attr_cpu_utility.attr, + &dev_attr_cpumask.attr, + &dev_attr_patrol_times.attr, + &dev_attr_available_inspector.attr, + &dev_attr_current_inspector.attr, + NULL +}; + +static struct attribute_group cpuinspect_attr_group = { + .attrs = cpuinspect_attrs, + .name = "cpuinspect", +}; + +/** + * cpuinspect_add_interface - add CPU global sysfs attributes + * @dev: the target device + */ +int cpuinspect_add_interface(struct device *dev) +{ + return sysfs_create_group(&dev->kobj, &cpuinspect_attr_group); +} + +/** + * cpuinspect_remove_interface - remove CPU global sysfs attributes + * @dev: the target device + */ +void cpuinspect_remove_interface(struct device *dev) +{ + sysfs_remove_group(&dev->kobj, &cpuinspect_attr_group); +} diff --git a/include/linux/cpuinspect.h b/include/linux/cpuinspect.h new file mode 100644 index 000000000000..5bf1c57f73ca --- /dev/null +++ b/include/linux/cpuinspect.h @@ -0,0 +1,40 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * cpuinspect.h - a generic framework for CPU online inspection + * + * Copyright (c) 2023 Yu Liao liaoyu15@huawei.com + */ + +#ifndef __LINUX_CPUINSPECT_H +#define __LINUX_CPUINSPECT_H + +#include <linux/percpu.h> +#include <linux/list.h> +#include <linux/spinlock.h> + +#define CPUINSPECT_NAME_LEN 16 + +/** + * struct cpu_inspector - CPU Inspection driver. Inspection code may run in + * kernel, BIOS, trusted OS, etc., and contains many test cases. All test + * cases can be divided into multiple or one group, provied a function + * to start inspection for a specified group. + * + * @name: Pointer to inspector name + * @list: List head for registration (internal) + * @group_num: Number of inspection code groups + * @start_inspect: Function to start inspect process, passes group + * number as a argument + */ +struct cpu_inspector { + const char name[CPUINSPECT_NAME_LEN]; + struct list_head list; + unsigned int group_num; + + int (*start_inspect)(unsigned int group); +}; + +extern int cpuinspect_register_inspector(struct cpu_inspector *insp); +extern int cpuinspect_unregister_inspector(struct cpu_inspector *insp); + +#endif /* __LINUX_CPUINSPECT_H */