From 3022c6a1b4b76c40aab9dcdf5142c501f3d3ae8c Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams@intel.com>
Date: Thu, 25 Jun 2020 16:51:03 -0700
Subject: [PATCH] driver-core: Introduce DEVICE_ATTR_ADMIN_{RO,RW}
References: bsc#1176486 ltc#188130
Patch-mainline: v5.9-rc1
Git-commit: 3022c6a1b4b76c40aab9dcdf5142c501f3d3ae8c
A common pattern for using plain DEVICE_ATTR() instead of
DEVICE_ATTR_RO() and DEVICE_ATTR_RW() is for attributes that want to
limit read to only root. I.e. many users of DEVICE_ATTR() are
specifying 0400 or 0600 for permissions.
Given the expectation that CAP_SYS_ADMIN is needed to access these
sensitive attributes and an explicit helper with the _ADMIN_ identifier
for DEVICE_ATTR_ADMIN_{RO,RW}.
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/159312906372.1850128.11611897078988158727.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
include/linux/device.h | 4 ++++
include/linux/sysfs.h | 7 +++++++
2 files changed, 11 insertions(+)
diff --git a/include/linux/device.h b/include/linux/device.h
index 15460a5ac024..d7c2570368fa 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -128,8 +128,12 @@ ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
__ATTR_PREALLOC(_name, _mode, _show, _store)
#define DEVICE_ATTR_RW(_name) \
struct device_attribute dev_attr_##_name = __ATTR_RW(_name)
+#define DEVICE_ATTR_ADMIN_RW(_name) \
+ struct device_attribute dev_attr_##_name = __ATTR_RW_MODE(_name, 0600)
#define DEVICE_ATTR_RO(_name) \
struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
+#define DEVICE_ATTR_ADMIN_RO(_name) \
+ struct device_attribute dev_attr_##_name = __ATTR_RO_MODE(_name, 0400)
#define DEVICE_ATTR_WO(_name) \
struct device_attribute dev_attr_##_name = __ATTR_WO(_name)
#define DEVICE_ULONG_ATTR(_name, _mode, _var) \
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 86067dbe7745..34e84122f635 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -123,6 +123,13 @@ struct attribute_group {
.show = _name##_show, \
}
+#define __ATTR_RW_MODE(_name, _mode) { \
+ .attr = { .name = __stringify(_name), \
+ .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \
+ .show = _name##_show, \
+ .store = _name##_store, \
+}
+
#define __ATTR_WO(_name) { \
.attr = { .name = __stringify(_name), .mode = 0200 }, \
.store = _name##_store, \
--
2.28.0