When booting a kernel with CONFIG_CFI_CLANG, there is a CFI failure when accessing any of the values under /sys/devices/system/cpu/intel_uncore_frequency/package_00_die_00: $ cat /sys/devices/system/cpu/intel_uncore_frequency/package_00_die_00/max_freq_khz fish: Job 1, 'cat /sys/devices/system/cpu/int…' terminated by signal SIGSEGV (Address boundary error) $ sudo dmesg &| grep 'CFI failure' [ 170.953925] CFI failure at kobj_attr_show+0x19/0x30 (target: show_max_freq_khz+0x0/0xc0 [intel_uncore_frequency_common]; expected type: 0xd34078c5 The sysfs callback functions such as show_domain_id() are written as if they are going to be called by dev_attr_show() but as the above message shows, they are instead called by kobj_attr_show(). kCFI checks that the destination of an indirect jump has the exact same type as the prototype of the function pointer it is called through and fails when they do not. These callbacks are called through kobj_attr_show() because uncore_root_kobj was initialized with kobject_create_and_add(), which means uncore_root_kobj has a ->sysfs_ops of kobj_sysfs_ops from kobject_create(), which uses kobj_attr_show() as its ->show() value. The only reason there has not been a more noticeable problem until this point is that 'struct kobj_attribute' and 'struct device_attribute' have the same layout, so getting the callback from container_of() works the same with either value. Change all the callbacks and their uses to be compatible with kobj_attr_show() and kobj_attr_store(), which resolves the kCFI failure and allows the sysfs files to work properly. Closes: https://github.com/ClangBuiltLinux/linux/issues/1974 Fixes: ae7b2ce57851 ("platform/x86/intel/uncore-freq: Use sysfs API to create attributes") Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx> --- I think I got the fixes tag right. I only started seeing this because of commit 27f2b08735c9 ("platform/x86: intel-uncore-freq: Add additional client processors"), which allows this driver to load on my i7-11700 test system but I think the commit in the Fixes tag incorrectly changes the types of the callbacks. --- .../uncore-frequency/uncore-frequency-common.c | 82 +++++++++++----------- .../uncore-frequency/uncore-frequency-common.h | 32 ++++----- 2 files changed, 57 insertions(+), 57 deletions(-) diff --git a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-common.c b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-common.c index 33ab207493e3..33bb58dc3f78 100644 --- a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-common.c +++ b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-common.c @@ -23,23 +23,23 @@ static int (*uncore_read)(struct uncore_data *data, unsigned int *min, unsigned static int (*uncore_write)(struct uncore_data *data, unsigned int input, unsigned int min_max); static int (*uncore_read_freq)(struct uncore_data *data, unsigned int *freq); -static ssize_t show_domain_id(struct device *dev, struct device_attribute *attr, char *buf) +static ssize_t show_domain_id(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { - struct uncore_data *data = container_of(attr, struct uncore_data, domain_id_dev_attr); + struct uncore_data *data = container_of(attr, struct uncore_data, domain_id_kobj_attr); return sprintf(buf, "%u\n", data->domain_id); } -static ssize_t show_fabric_cluster_id(struct device *dev, struct device_attribute *attr, char *buf) +static ssize_t show_fabric_cluster_id(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { - struct uncore_data *data = container_of(attr, struct uncore_data, fabric_cluster_id_dev_attr); + struct uncore_data *data = container_of(attr, struct uncore_data, fabric_cluster_id_kobj_attr); return sprintf(buf, "%u\n", data->cluster_id); } -static ssize_t show_package_id(struct device *dev, struct device_attribute *attr, char *buf) +static ssize_t show_package_id(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { - struct uncore_data *data = container_of(attr, struct uncore_data, package_id_dev_attr); + struct uncore_data *data = container_of(attr, struct uncore_data, package_id_kobj_attr); return sprintf(buf, "%u\n", data->package_id); } @@ -97,30 +97,30 @@ static ssize_t show_perf_status_freq_khz(struct uncore_data *data, char *buf) } #define store_uncore_min_max(name, min_max) \ - static ssize_t store_##name(struct device *dev, \ - struct device_attribute *attr, \ + static ssize_t store_##name(struct kobject *kobj, \ + struct kobj_attribute *attr, \ const char *buf, size_t count) \ { \ - struct uncore_data *data = container_of(attr, struct uncore_data, name##_dev_attr);\ + struct uncore_data *data = container_of(attr, struct uncore_data, name##_kobj_attr);\ \ return store_min_max_freq_khz(data, buf, count, \ min_max); \ } #define show_uncore_min_max(name, min_max) \ - static ssize_t show_##name(struct device *dev, \ - struct device_attribute *attr, char *buf)\ + static ssize_t show_##name(struct kobject *kobj, \ + struct kobj_attribute *attr, char *buf)\ { \ - struct uncore_data *data = container_of(attr, struct uncore_data, name##_dev_attr);\ + struct uncore_data *data = container_of(attr, struct uncore_data, name##_kobj_attr);\ \ return show_min_max_freq_khz(data, buf, min_max); \ } #define show_uncore_perf_status(name) \ - static ssize_t show_##name(struct device *dev, \ - struct device_attribute *attr, char *buf)\ + static ssize_t show_##name(struct kobject *kobj, \ + struct kobj_attribute *attr, char *buf)\ { \ - struct uncore_data *data = container_of(attr, struct uncore_data, name##_dev_attr);\ + struct uncore_data *data = container_of(attr, struct uncore_data, name##_kobj_attr);\ \ return show_perf_status_freq_khz(data, buf); \ } @@ -134,11 +134,11 @@ show_uncore_min_max(max_freq_khz, 1); show_uncore_perf_status(current_freq_khz); #define show_uncore_data(member_name) \ - static ssize_t show_##member_name(struct device *dev, \ - struct device_attribute *attr, char *buf)\ + static ssize_t show_##member_name(struct kobject *kobj, \ + struct kobj_attribute *attr, char *buf)\ { \ struct uncore_data *data = container_of(attr, struct uncore_data,\ - member_name##_dev_attr);\ + member_name##_kobj_attr);\ \ return sysfs_emit(buf, "%u\n", \ data->member_name); \ @@ -149,29 +149,29 @@ show_uncore_data(initial_max_freq_khz); #define init_attribute_rw(_name) \ do { \ - sysfs_attr_init(&data->_name##_dev_attr.attr); \ - data->_name##_dev_attr.show = show_##_name; \ - data->_name##_dev_attr.store = store_##_name; \ - data->_name##_dev_attr.attr.name = #_name; \ - data->_name##_dev_attr.attr.mode = 0644; \ + sysfs_attr_init(&data->_name##_kobj_attr.attr); \ + data->_name##_kobj_attr.show = show_##_name; \ + data->_name##_kobj_attr.store = store_##_name; \ + data->_name##_kobj_attr.attr.name = #_name; \ + data->_name##_kobj_attr.attr.mode = 0644; \ } while (0) #define init_attribute_ro(_name) \ do { \ - sysfs_attr_init(&data->_name##_dev_attr.attr); \ - data->_name##_dev_attr.show = show_##_name; \ - data->_name##_dev_attr.store = NULL; \ - data->_name##_dev_attr.attr.name = #_name; \ - data->_name##_dev_attr.attr.mode = 0444; \ + sysfs_attr_init(&data->_name##_kobj_attr.attr); \ + data->_name##_kobj_attr.show = show_##_name; \ + data->_name##_kobj_attr.store = NULL; \ + data->_name##_kobj_attr.attr.name = #_name; \ + data->_name##_kobj_attr.attr.mode = 0444; \ } while (0) #define init_attribute_root_ro(_name) \ do { \ - sysfs_attr_init(&data->_name##_dev_attr.attr); \ - data->_name##_dev_attr.show = show_##_name; \ - data->_name##_dev_attr.store = NULL; \ - data->_name##_dev_attr.attr.name = #_name; \ - data->_name##_dev_attr.attr.mode = 0400; \ + sysfs_attr_init(&data->_name##_kobj_attr.attr); \ + data->_name##_kobj_attr.show = show_##_name; \ + data->_name##_kobj_attr.store = NULL; \ + data->_name##_kobj_attr.attr.name = #_name; \ + data->_name##_kobj_attr.attr.mode = 0400; \ } while (0) static int create_attr_group(struct uncore_data *data, char *name) @@ -186,21 +186,21 @@ static int create_attr_group(struct uncore_data *data, char *name) if (data->domain_id != UNCORE_DOMAIN_ID_INVALID) { init_attribute_root_ro(domain_id); - data->uncore_attrs[index++] = &data->domain_id_dev_attr.attr; + data->uncore_attrs[index++] = &data->domain_id_kobj_attr.attr; init_attribute_root_ro(fabric_cluster_id); - data->uncore_attrs[index++] = &data->fabric_cluster_id_dev_attr.attr; + data->uncore_attrs[index++] = &data->fabric_cluster_id_kobj_attr.attr; init_attribute_root_ro(package_id); - data->uncore_attrs[index++] = &data->package_id_dev_attr.attr; + data->uncore_attrs[index++] = &data->package_id_kobj_attr.attr; } - data->uncore_attrs[index++] = &data->max_freq_khz_dev_attr.attr; - data->uncore_attrs[index++] = &data->min_freq_khz_dev_attr.attr; - data->uncore_attrs[index++] = &data->initial_min_freq_khz_dev_attr.attr; - data->uncore_attrs[index++] = &data->initial_max_freq_khz_dev_attr.attr; + data->uncore_attrs[index++] = &data->max_freq_khz_kobj_attr.attr; + data->uncore_attrs[index++] = &data->min_freq_khz_kobj_attr.attr; + data->uncore_attrs[index++] = &data->initial_min_freq_khz_kobj_attr.attr; + data->uncore_attrs[index++] = &data->initial_max_freq_khz_kobj_attr.attr; ret = uncore_read_freq(data, &freq); if (!ret) - data->uncore_attrs[index++] = &data->current_freq_khz_dev_attr.attr; + data->uncore_attrs[index++] = &data->current_freq_khz_kobj_attr.attr; data->uncore_attrs[index] = NULL; diff --git a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-common.h b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-common.h index 7afb69977c7e..0e5bf507e555 100644 --- a/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-common.h +++ b/drivers/platform/x86/intel/uncore-frequency/uncore-frequency-common.h @@ -26,14 +26,14 @@ * @instance_id: Unique instance id to append to directory name * @name: Sysfs entry name for this instance * @uncore_attr_group: Attribute group storage - * @max_freq_khz_dev_attr: Storage for device attribute max_freq_khz - * @mix_freq_khz_dev_attr: Storage for device attribute min_freq_khz - * @initial_max_freq_khz_dev_attr: Storage for device attribute initial_max_freq_khz - * @initial_min_freq_khz_dev_attr: Storage for device attribute initial_min_freq_khz - * @current_freq_khz_dev_attr: Storage for device attribute current_freq_khz - * @domain_id_dev_attr: Storage for device attribute domain_id - * @fabric_cluster_id_dev_attr: Storage for device attribute fabric_cluster_id - * @package_id_dev_attr: Storage for device attribute package_id + * @max_freq_khz_kobj_attr: Storage for kobject attribute max_freq_khz + * @mix_freq_khz_kobj_attr: Storage for kobject attribute min_freq_khz + * @initial_max_freq_khz_kobj_attr: Storage for kobject attribute initial_max_freq_khz + * @initial_min_freq_khz_kobj_attr: Storage for kobject attribute initial_min_freq_khz + * @current_freq_khz_kobj_attr: Storage for kobject attribute current_freq_khz + * @domain_id_kobj_attr: Storage for kobject attribute domain_id + * @fabric_cluster_id_kobj_attr: Storage for kobject attribute fabric_cluster_id + * @package_id_kobj_attr: Storage for kobject attribute package_id * @uncore_attrs: Attribute storage for group creation * * This structure is used to encapsulate all data related to uncore sysfs @@ -53,14 +53,14 @@ struct uncore_data { char name[32]; struct attribute_group uncore_attr_group; - struct device_attribute max_freq_khz_dev_attr; - struct device_attribute min_freq_khz_dev_attr; - struct device_attribute initial_max_freq_khz_dev_attr; - struct device_attribute initial_min_freq_khz_dev_attr; - struct device_attribute current_freq_khz_dev_attr; - struct device_attribute domain_id_dev_attr; - struct device_attribute fabric_cluster_id_dev_attr; - struct device_attribute package_id_dev_attr; + struct kobj_attribute max_freq_khz_kobj_attr; + struct kobj_attribute min_freq_khz_kobj_attr; + struct kobj_attribute initial_max_freq_khz_kobj_attr; + struct kobj_attribute initial_min_freq_khz_kobj_attr; + struct kobj_attribute current_freq_khz_kobj_attr; + struct kobj_attribute domain_id_kobj_attr; + struct kobj_attribute fabric_cluster_id_kobj_attr; + struct kobj_attribute package_id_kobj_attr; struct attribute *uncore_attrs[9]; }; --- base-commit: 236f7d8034ff401d02fa6d74bae494a2b54e1834 change-id: 20240104-intel-uncore-freq-kcfi-fix-6ef07053db58 Best regards, -- Nathan Chancellor <nathan@xxxxxxxxxx>
