From a169a663bfa8198f33a5c1002634cc89e5128025 Mon Sep 17 00:00:00 2001 From: Zijun Hu Date: Thu, 22 Aug 2024 20:38:35 +0800 Subject: [PATCH] driver core: class: Check namespace relevant parameters in class_register() Device class has two namespace relevant fields which are usually associated by the following usage: struct class { ... const struct kobj_ns_type_operations *ns_type; const void *(*namespace)(const struct device *dev); ... } if (dev->class && dev->class->ns_type) dev->class->namespace(dev); (1) The usage looks weird since it checks @ns_type but calls namespace() (2) The usage implies both fields have dependency but their dependency is not currently enforced yet. It is found for all existing class definitions that the other filed is also assigned once one is assigned in current kernel tree. Fixed by enforcing above existing dependency that both fields are required for a device class to support namespace via parameter checks. Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20240822-class_fix-v1-1-2a6d38ba913a@quicinc.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/class.c | 11 +++++++++++ drivers/base/core.c | 2 +- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/base/class.c b/drivers/base/class.c index ae22fa992c049..cb5359235c702 100644 --- a/drivers/base/class.c +++ b/drivers/base/class.c @@ -183,6 +183,17 @@ int class_register(const struct class *cls) pr_debug("device class '%s': registering\n", cls->name); + if (cls->ns_type && !cls->namespace) { + pr_err("%s: class '%s' does not have namespace\n", + __func__, cls->name); + return -EINVAL; + } + if (!cls->ns_type && cls->namespace) { + pr_err("%s: class '%s' does not have ns_type\n", + __func__, cls->name); + return -EINVAL; + } + cp = kzalloc(sizeof(*cp), GFP_KERNEL); if (!cp) return -ENOMEM; diff --git a/drivers/base/core.c b/drivers/base/core.c index ec2197aec0b72..30408a4a4927a 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2584,7 +2584,7 @@ static const void *device_namespace(const struct kobject *kobj) const struct device *dev = kobj_to_dev(kobj); const void *ns = NULL; - if (dev->class && dev->class->ns_type) + if (dev->class && dev->class->namespace) ns = dev->class->namespace(dev); return ns; -- 2.50.1