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/firmware/dmi-id.c | 265 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 265 insertions(+) create mode 100644 drivers/firmware/dmi-id.c (limited to 'drivers/firmware/dmi-id.c') diff --git a/drivers/firmware/dmi-id.c b/drivers/firmware/dmi-id.c new file mode 100644 index 000000000..477a37e2e --- /dev/null +++ b/drivers/firmware/dmi-id.c @@ -0,0 +1,265 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Export SMBIOS/DMI info via sysfs to userspace + * + * Copyright 2007, Lennart Poettering + */ + +#include +#include +#include +#include +#include +#include + +struct dmi_device_attribute{ + struct device_attribute dev_attr; + int field; +}; +#define to_dmi_dev_attr(_dev_attr) \ + container_of(_dev_attr, struct dmi_device_attribute, dev_attr) + +static ssize_t sys_dmi_field_show(struct device *dev, + struct device_attribute *attr, + char *page) +{ + int field = to_dmi_dev_attr(attr)->field; + ssize_t len; + len = scnprintf(page, PAGE_SIZE, "%s\n", dmi_get_system_info(field)); + page[len-1] = '\n'; + return len; +} + +#define DMI_ATTR(_name, _mode, _show, _field) \ + { .dev_attr = __ATTR(_name, _mode, _show, NULL), \ + .field = _field } + +#define DEFINE_DMI_ATTR_WITH_SHOW(_name, _mode, _field) \ +static struct dmi_device_attribute sys_dmi_##_name##_attr = \ + DMI_ATTR(_name, _mode, sys_dmi_field_show, _field); + +DEFINE_DMI_ATTR_WITH_SHOW(bios_vendor, 0444, DMI_BIOS_VENDOR); +DEFINE_DMI_ATTR_WITH_SHOW(bios_version, 0444, DMI_BIOS_VERSION); +DEFINE_DMI_ATTR_WITH_SHOW(bios_date, 0444, DMI_BIOS_DATE); +DEFINE_DMI_ATTR_WITH_SHOW(sys_vendor, 0444, DMI_SYS_VENDOR); +DEFINE_DMI_ATTR_WITH_SHOW(bios_release, 0444, DMI_BIOS_RELEASE); +DEFINE_DMI_ATTR_WITH_SHOW(ec_firmware_release, 0444, DMI_EC_FIRMWARE_RELEASE); +DEFINE_DMI_ATTR_WITH_SHOW(product_name, 0444, DMI_PRODUCT_NAME); +DEFINE_DMI_ATTR_WITH_SHOW(product_version, 0444, DMI_PRODUCT_VERSION); +DEFINE_DMI_ATTR_WITH_SHOW(product_serial, 0400, DMI_PRODUCT_SERIAL); +DEFINE_DMI_ATTR_WITH_SHOW(product_uuid, 0400, DMI_PRODUCT_UUID); +DEFINE_DMI_ATTR_WITH_SHOW(product_sku, 0444, DMI_PRODUCT_SKU); +DEFINE_DMI_ATTR_WITH_SHOW(product_family, 0444, DMI_PRODUCT_FAMILY); +DEFINE_DMI_ATTR_WITH_SHOW(board_vendor, 0444, DMI_BOARD_VENDOR); +DEFINE_DMI_ATTR_WITH_SHOW(board_name, 0444, DMI_BOARD_NAME); +DEFINE_DMI_ATTR_WITH_SHOW(board_version, 0444, DMI_BOARD_VERSION); +DEFINE_DMI_ATTR_WITH_SHOW(board_serial, 0400, DMI_BOARD_SERIAL); +DEFINE_DMI_ATTR_WITH_SHOW(board_asset_tag, 0444, DMI_BOARD_ASSET_TAG); +DEFINE_DMI_ATTR_WITH_SHOW(chassis_vendor, 0444, DMI_CHASSIS_VENDOR); +DEFINE_DMI_ATTR_WITH_SHOW(chassis_type, 0444, DMI_CHASSIS_TYPE); +DEFINE_DMI_ATTR_WITH_SHOW(chassis_version, 0444, DMI_CHASSIS_VERSION); +DEFINE_DMI_ATTR_WITH_SHOW(chassis_serial, 0400, DMI_CHASSIS_SERIAL); +DEFINE_DMI_ATTR_WITH_SHOW(chassis_asset_tag, 0444, DMI_CHASSIS_ASSET_TAG); + +static void ascii_filter(char *d, const char *s) +{ + /* Filter out characters we don't want to see in the modalias string */ + for (; *s; s++) + if (*s > ' ' && *s < 127 && *s != ':') + *(d++) = *s; + + *d = 0; +} + +static ssize_t get_modalias(char *buffer, size_t buffer_size) +{ + /* + * Note new fields need to be added at the end to keep compatibility + * with udev's hwdb which does matches on "`cat dmi/id/modalias`*". + */ + static const struct mafield { + const char *prefix; + int field; + } fields[] = { + { "bvn", DMI_BIOS_VENDOR }, + { "bvr", DMI_BIOS_VERSION }, + { "bd", DMI_BIOS_DATE }, + { "br", DMI_BIOS_RELEASE }, + { "efr", DMI_EC_FIRMWARE_RELEASE }, + { "svn", DMI_SYS_VENDOR }, + { "pn", DMI_PRODUCT_NAME }, + { "pvr", DMI_PRODUCT_VERSION }, + { "rvn", DMI_BOARD_VENDOR }, + { "rn", DMI_BOARD_NAME }, + { "rvr", DMI_BOARD_VERSION }, + { "cvn", DMI_CHASSIS_VENDOR }, + { "ct", DMI_CHASSIS_TYPE }, + { "cvr", DMI_CHASSIS_VERSION }, + { "sku", DMI_PRODUCT_SKU }, + { "pfa", DMI_PRODUCT_FAMILY }, + { NULL, DMI_NONE } + }; + + ssize_t l, left; + char *p; + const struct mafield *f; + + strcpy(buffer, "dmi"); + p = buffer + 3; left = buffer_size - 4; + + for (f = fields; f->prefix && left > 0; f++) { + const char *c; + char *t; + + c = dmi_get_system_info(f->field); + if (!c) + continue; + + t = kmalloc(strlen(c) + 1, GFP_KERNEL); + if (!t) + break; + ascii_filter(t, c); + l = scnprintf(p, left, ":%s%s", f->prefix, t); + kfree(t); + + p += l; + left -= l; + } + + p[0] = ':'; + p[1] = 0; + + return p - buffer + 1; +} + +static ssize_t sys_dmi_modalias_show(struct device *dev, + struct device_attribute *attr, char *page) +{ + ssize_t r; + r = get_modalias(page, PAGE_SIZE-1); + page[r] = '\n'; + page[r+1] = 0; + return r+1; +} + +static struct device_attribute sys_dmi_modalias_attr = + __ATTR(modalias, 0444, sys_dmi_modalias_show, NULL); + +static struct attribute *sys_dmi_attributes[DMI_STRING_MAX+2]; + +static struct attribute_group sys_dmi_attribute_group = { + .attrs = sys_dmi_attributes, +}; + +static const struct attribute_group* sys_dmi_attribute_groups[] = { + &sys_dmi_attribute_group, + NULL +}; + +static int dmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env) +{ + ssize_t len; + + if (add_uevent_var(env, "MODALIAS=")) + return -ENOMEM; + len = get_modalias(&env->buf[env->buflen - 1], + sizeof(env->buf) - env->buflen); + if (len >= (sizeof(env->buf) - env->buflen)) + return -ENOMEM; + env->buflen += len; + return 0; +} + +static void dmi_dev_release(struct device *dev) +{ + kfree(dev); +} + +static struct class dmi_class = { + .name = "dmi", + .dev_release = dmi_dev_release, + .dev_uevent = dmi_dev_uevent, +}; + +static struct device *dmi_dev; + +/* Initialization */ + +#define ADD_DMI_ATTR(_name, _field) \ + if (dmi_get_system_info(_field)) \ + sys_dmi_attributes[i++] = &sys_dmi_##_name##_attr.dev_attr.attr; + +/* In a separate function to keep gcc 3.2 happy - do NOT merge this in + dmi_id_init! */ +static void __init dmi_id_init_attr_table(void) +{ + int i; + + /* Not necessarily all DMI fields are available on all + * systems, hence let's built an attribute table of just + * what's available */ + i = 0; + ADD_DMI_ATTR(bios_vendor, DMI_BIOS_VENDOR); + ADD_DMI_ATTR(bios_version, DMI_BIOS_VERSION); + ADD_DMI_ATTR(bios_date, DMI_BIOS_DATE); + ADD_DMI_ATTR(bios_release, DMI_BIOS_RELEASE); + ADD_DMI_ATTR(ec_firmware_release, DMI_EC_FIRMWARE_RELEASE); + ADD_DMI_ATTR(sys_vendor, DMI_SYS_VENDOR); + ADD_DMI_ATTR(product_name, DMI_PRODUCT_NAME); + ADD_DMI_ATTR(product_version, DMI_PRODUCT_VERSION); + ADD_DMI_ATTR(product_serial, DMI_PRODUCT_SERIAL); + ADD_DMI_ATTR(product_uuid, DMI_PRODUCT_UUID); + ADD_DMI_ATTR(product_family, DMI_PRODUCT_FAMILY); + ADD_DMI_ATTR(product_sku, DMI_PRODUCT_SKU); + ADD_DMI_ATTR(board_vendor, DMI_BOARD_VENDOR); + ADD_DMI_ATTR(board_name, DMI_BOARD_NAME); + ADD_DMI_ATTR(board_version, DMI_BOARD_VERSION); + ADD_DMI_ATTR(board_serial, DMI_BOARD_SERIAL); + ADD_DMI_ATTR(board_asset_tag, DMI_BOARD_ASSET_TAG); + ADD_DMI_ATTR(chassis_vendor, DMI_CHASSIS_VENDOR); + ADD_DMI_ATTR(chassis_type, DMI_CHASSIS_TYPE); + ADD_DMI_ATTR(chassis_version, DMI_CHASSIS_VERSION); + ADD_DMI_ATTR(chassis_serial, DMI_CHASSIS_SERIAL); + ADD_DMI_ATTR(chassis_asset_tag, DMI_CHASSIS_ASSET_TAG); + sys_dmi_attributes[i++] = &sys_dmi_modalias_attr.attr; +} + +static int __init dmi_id_init(void) +{ + int ret; + + if (!dmi_available) + return -ENODEV; + + dmi_id_init_attr_table(); + + ret = class_register(&dmi_class); + if (ret) + return ret; + + dmi_dev = kzalloc_obj(*dmi_dev); + if (!dmi_dev) { + ret = -ENOMEM; + goto fail_class_unregister; + } + + dmi_dev->class = &dmi_class; + dev_set_name(dmi_dev, "id"); + dmi_dev->groups = sys_dmi_attribute_groups; + + ret = device_register(dmi_dev); + if (ret) + goto fail_put_dmi_dev; + + return 0; + +fail_put_dmi_dev: + put_device(dmi_dev); + +fail_class_unregister: + class_unregister(&dmi_class); + + return ret; +} + +arch_initcall(dmi_id_init); -- cgit v1.3.1