From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/edac/scrub.c | 210 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 210 insertions(+) create mode 100644 drivers/edac/scrub.c (limited to 'drivers/edac/scrub.c') diff --git a/drivers/edac/scrub.c b/drivers/edac/scrub.c new file mode 100644 index 000000000..f9d02af2f --- /dev/null +++ b/drivers/edac/scrub.c @@ -0,0 +1,210 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * The generic EDAC scrub driver controls the memory scrubbers in the + * system. The common sysfs scrub interface abstracts the control of + * various arbitrary scrubbing functionalities into a unified set of + * functions. + * + * Copyright (c) 2024-2025 HiSilicon Limited. + */ + +#include + +enum edac_scrub_attributes { + SCRUB_ADDRESS, + SCRUB_SIZE, + SCRUB_ENABLE_BACKGROUND, + SCRUB_MIN_CYCLE_DURATION, + SCRUB_MAX_CYCLE_DURATION, + SCRUB_CUR_CYCLE_DURATION, + SCRUB_MAX_ATTRS +}; + +struct edac_scrub_dev_attr { + struct device_attribute dev_attr; + u8 instance; +}; + +struct edac_scrub_context { + char name[EDAC_FEAT_NAME_LEN]; + struct edac_scrub_dev_attr scrub_dev_attr[SCRUB_MAX_ATTRS]; + struct attribute *scrub_attrs[SCRUB_MAX_ATTRS + 1]; + struct attribute_group group; +}; + +#define TO_SCRUB_DEV_ATTR(_dev_attr) \ + container_of(_dev_attr, struct edac_scrub_dev_attr, dev_attr) + +#define EDAC_SCRUB_ATTR_SHOW(attrib, cb, type, format) \ +static ssize_t attrib##_show(struct device *ras_feat_dev, \ + struct device_attribute *attr, char *buf) \ +{ \ + u8 inst = TO_SCRUB_DEV_ATTR(attr)->instance; \ + struct edac_dev_feat_ctx *ctx = dev_get_drvdata(ras_feat_dev); \ + const struct edac_scrub_ops *ops = ctx->scrub[inst].scrub_ops; \ + type data; \ + int ret; \ + \ + ret = ops->cb(ras_feat_dev->parent, ctx->scrub[inst].private, &data); \ + if (ret) \ + return ret; \ + \ + return sysfs_emit(buf, format, data); \ +} + +EDAC_SCRUB_ATTR_SHOW(addr, read_addr, u64, "0x%llx\n") +EDAC_SCRUB_ATTR_SHOW(size, read_size, u64, "0x%llx\n") +EDAC_SCRUB_ATTR_SHOW(enable_background, get_enabled_bg, bool, "%u\n") +EDAC_SCRUB_ATTR_SHOW(min_cycle_duration, get_min_cycle, u32, "%u\n") +EDAC_SCRUB_ATTR_SHOW(max_cycle_duration, get_max_cycle, u32, "%u\n") +EDAC_SCRUB_ATTR_SHOW(current_cycle_duration, get_cycle_duration, u32, "%u\n") + +#define EDAC_SCRUB_ATTR_STORE(attrib, cb, type, conv_func) \ +static ssize_t attrib##_store(struct device *ras_feat_dev, \ + struct device_attribute *attr, \ + const char *buf, size_t len) \ +{ \ + u8 inst = TO_SCRUB_DEV_ATTR(attr)->instance; \ + struct edac_dev_feat_ctx *ctx = dev_get_drvdata(ras_feat_dev); \ + const struct edac_scrub_ops *ops = ctx->scrub[inst].scrub_ops; \ + type data; \ + int ret; \ + \ + ret = conv_func(buf, 0, &data); \ + if (ret < 0) \ + return ret; \ + \ + ret = ops->cb(ras_feat_dev->parent, ctx->scrub[inst].private, data); \ + if (ret) \ + return ret; \ + \ + return len; \ +} + +EDAC_SCRUB_ATTR_STORE(addr, write_addr, u64, kstrtou64) +EDAC_SCRUB_ATTR_STORE(size, write_size, u64, kstrtou64) +EDAC_SCRUB_ATTR_STORE(enable_background, set_enabled_bg, unsigned long, kstrtoul) +EDAC_SCRUB_ATTR_STORE(current_cycle_duration, set_cycle_duration, unsigned long, kstrtoul) + +static umode_t scrub_attr_visible(struct kobject *kobj, struct attribute *a, int attr_id) +{ + struct device *ras_feat_dev = kobj_to_dev(kobj); + struct device_attribute *dev_attr = container_of(a, struct device_attribute, attr); + u8 inst = TO_SCRUB_DEV_ATTR(dev_attr)->instance; + struct edac_dev_feat_ctx *ctx = dev_get_drvdata(ras_feat_dev); + const struct edac_scrub_ops *ops = ctx->scrub[inst].scrub_ops; + + switch (attr_id) { + case SCRUB_ADDRESS: + if (ops->read_addr) { + if (ops->write_addr) + return a->mode; + else + return 0444; + } + break; + case SCRUB_SIZE: + if (ops->read_size) { + if (ops->write_size) + return a->mode; + else + return 0444; + } + break; + case SCRUB_ENABLE_BACKGROUND: + if (ops->get_enabled_bg) { + if (ops->set_enabled_bg) + return a->mode; + else + return 0444; + } + break; + case SCRUB_MIN_CYCLE_DURATION: + if (ops->get_min_cycle) + return a->mode; + break; + case SCRUB_MAX_CYCLE_DURATION: + if (ops->get_max_cycle) + return a->mode; + break; + case SCRUB_CUR_CYCLE_DURATION: + if (ops->get_cycle_duration) { + if (ops->set_cycle_duration) + return a->mode; + else + return 0444; + } + break; + default: + break; + } + + return 0; +} + +#define EDAC_SCRUB_ATTR_RO(_name, _instance) \ + ((struct edac_scrub_dev_attr) { .dev_attr = __ATTR_RO(_name), \ + .instance = _instance }) + +#define EDAC_SCRUB_ATTR_WO(_name, _instance) \ + ((struct edac_scrub_dev_attr) { .dev_attr = __ATTR_WO(_name), \ + .instance = _instance }) + +#define EDAC_SCRUB_ATTR_RW(_name, _instance) \ + ((struct edac_scrub_dev_attr) { .dev_attr = __ATTR_RW(_name), \ + .instance = _instance }) + +static int scrub_create_desc(struct device *scrub_dev, + const struct attribute_group **attr_groups, u8 instance) +{ + struct edac_scrub_context *scrub_ctx; + struct attribute_group *group; + int i; + struct edac_scrub_dev_attr dev_attr[] = { + [SCRUB_ADDRESS] = EDAC_SCRUB_ATTR_RW(addr, instance), + [SCRUB_SIZE] = EDAC_SCRUB_ATTR_RW(size, instance), + [SCRUB_ENABLE_BACKGROUND] = EDAC_SCRUB_ATTR_RW(enable_background, instance), + [SCRUB_MIN_CYCLE_DURATION] = EDAC_SCRUB_ATTR_RO(min_cycle_duration, instance), + [SCRUB_MAX_CYCLE_DURATION] = EDAC_SCRUB_ATTR_RO(max_cycle_duration, instance), + [SCRUB_CUR_CYCLE_DURATION] = EDAC_SCRUB_ATTR_RW(current_cycle_duration, instance) + }; + + scrub_ctx = devm_kzalloc(scrub_dev, sizeof(*scrub_ctx), GFP_KERNEL); + if (!scrub_ctx) + return -ENOMEM; + + group = &scrub_ctx->group; + for (i = 0; i < SCRUB_MAX_ATTRS; i++) { + memcpy(&scrub_ctx->scrub_dev_attr[i], &dev_attr[i], sizeof(dev_attr[i])); + sysfs_attr_init(&scrub_ctx->scrub_dev_attr[i].dev_attr.attr); + scrub_ctx->scrub_attrs[i] = &scrub_ctx->scrub_dev_attr[i].dev_attr.attr; + } + sprintf(scrub_ctx->name, "%s%d", "scrub", instance); + group->name = scrub_ctx->name; + group->attrs = scrub_ctx->scrub_attrs; + group->is_visible = scrub_attr_visible; + + attr_groups[0] = group; + + return 0; +} + +/** + * edac_scrub_get_desc - get EDAC scrub descriptors + * @scrub_dev: client device, with scrub support + * @attr_groups: pointer to attribute group container + * @instance: device's scrub instance number. + * + * Return: + * * %0 - Success. + * * %-EINVAL - Invalid parameters passed. + * * %-ENOMEM - Dynamic memory allocation failed. + */ +int edac_scrub_get_desc(struct device *scrub_dev, + const struct attribute_group **attr_groups, u8 instance) +{ + if (!scrub_dev || !attr_groups) + return -EINVAL; + + return scrub_create_desc(scrub_dev, attr_groups, instance); +} -- cgit v1.3.1