This is non-functional change to prepare the device cgroup code
for adding eBPF-based controller for cgroups v2.
The patch performs the following changes:
1) __devcgroup_inode_permission() and devcgroup_inode_mknod()
are moving to the device-cgroup.h and converting into static inline.
2) __devcgroup_check_permission() is exported.
3) devcgroup_check_permission() wrapper is introduced to be used
by both existing and new bpf-based implementations.
Signed-off-by: Roman Gushchin <g...@fb.com>
Acked-by: Tejun Heo <t...@kernel.org>
Acked-by: Alexei Starovoitov <a...@kernel.org>
---
include/linux/device_cgroup.h | 61 ++++++++++++++++++++++++++++++++++++++++---
security/device_cgroup.c | 47 ++-------------------------------
2 files changed, 59 insertions(+), 49 deletions(-)
diff --git a/include/linux/device_cgroup.h b/include/linux/device_cgroup.h
index 8b64221b432b..1e42d33accbf 100644
--- a/include/linux/device_cgroup.h
+++ b/include/linux/device_cgroup.h
@@ -1,16 +1,69 @@
#include <linux/fs.h>
+#define DEVCG_ACC_MKNOD 1
+#define DEVCG_ACC_READ 2
+#define DEVCG_ACC_WRITE 4
+#define DEVCG_ACC_MASK (DEVCG_ACC_MKNOD | DEVCG_ACC_READ | DEVCG_ACC_WRITE)
+
+#define DEVCG_DEV_BLOCK 1
+#define DEVCG_DEV_CHAR 2
+#define DEVCG_DEV_ALL 4 /* this represents all devices */
+
+#ifdef CONFIG_CGROUP_DEVICE
+extern int __devcgroup_check_permission(short type, u32 major, u32 minor,
+ short access);
+#else
+static inline int __devcgroup_check_permission(short type, u32 major, u32
minor,
+ short access)
+{ return 0; }
+#endif
+
#ifdef CONFIG_CGROUP_DEVICE
-extern int __devcgroup_inode_permission(struct inode *inode, int mask);
-extern int devcgroup_inode_mknod(int mode, dev_t dev);
+static inline int devcgroup_check_permission(short type, u32 major, u32 minor,
+ short access)
+{
+ return __devcgroup_check_permission(type, major, minor, access);
+}
+
static inline int devcgroup_inode_permission(struct inode *inode, int mask)
{
+ short type, access = 0;
+
if (likely(!inode->i_rdev))
return 0;
- if (!S_ISBLK(inode->i_mode) && !S_ISCHR(inode->i_mode))
+
+ if (S_ISBLK(inode->i_mode))
+ type = DEVCG_DEV_BLOCK;
+ else if (S_ISCHR(inode->i_mode))
+ type = DEVCG_DEV_CHAR;
+ else
return 0;
- return __devcgroup_inode_permission(inode, mask);
+
+ if (mask & MAY_WRITE)
+ access |= DEVCG_ACC_WRITE;
+ if (mask & MAY_READ)
+ access |= DEVCG_ACC_READ;
+
+ return devcgroup_check_permission(type, imajor(inode), iminor(inode),
+ access);
}
+
+static inline int devcgroup_inode_mknod(int mode, dev_t dev)
+{
+ short type;
+
+ if (!S_ISBLK(mode) && !S_ISCHR(mode))
+ return 0;
+
+ if (S_ISBLK(mode))
+ type = DEVCG_DEV_BLOCK;
+ else
+ type = DEVCG_DEV_CHAR;
+
+ return devcgroup_check_permission(type, MAJOR(dev), MINOR(dev),
+ DEVCG_ACC_MKNOD);
+}
+
#else
static inline int devcgroup_inode_permission(struct inode *inode, int mask)
{ return 0; }
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 76cc0cbbb10d..c54692208dcb 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -14,15 +14,6 @@
#include <linux/rcupdate.h>
#include <linux/mutex.h>
-#define DEVCG_ACC_MKNOD 1
-#define DEVCG_ACC_READ 2
-#define DEVCG_ACC_WRITE 4
-#define DEVCG_ACC_MASK (DEVCG_ACC_MKNOD | DEVCG_ACC_READ | DEVCG_ACC_WRITE)
-
-#define DEVCG_DEV_BLOCK 1
-#define DEVCG_DEV_CHAR 2
-#define DEVCG_DEV_ALL 4 /* this represents all devices */
-
static DEFINE_MUTEX(devcgroup_mutex);
enum devcg_behavior {
@@ -809,8 +800,8 @@ struct cgroup_subsys devices_cgrp_subsys = {
*
* returns 0 on success, -EPERM case the operation is not permitted
*/
-static int __devcgroup_check_permission(short type, u32 major, u32 minor,
- short access)
+int __devcgroup_check_permission(short type, u32 major, u32 minor,
+ short access)
{
struct dev_cgroup *dev_cgroup;
bool rc;
@@ -832,37 +823,3 @@ static int __devcgroup_check_permission(short type, u32
major, u32 minor,
return 0;
}
-
-int __devcgroup_inode_permission(struct inode *inode, int mask)
-{
- short type, access = 0;
-
- if (S_ISBLK(inode->i_mode))
- type = DEVCG_DEV_BLOCK;
- if (S_ISCHR(inode->i_mode))
- type = DEVCG_DEV_CHAR;
- if (mask & MAY_WRITE)
- access |= DEVCG_ACC_WRITE;
- if (mask & MAY_READ)
- access |= DEVCG_ACC_READ;
-
- return __devcgroup_check_permission(type, imajor(inode), iminor(inode),
- access);
-}
-
-int devcgroup_inode_mknod(int mode, dev_t dev)
-{
- short type;
-
- if (!S_ISBLK(mode) && !S_ISCHR(mode))
- return 0;
-
- if (S_ISBLK(mode))
- type = DEVCG_DEV_BLOCK;
- else
- type = DEVCG_DEV_CHAR;
-
- return __devcgroup_check_permission(type, MAJOR(dev), MINOR(dev),
- DEVCG_ACC_MKNOD);
-
-}
--
2.13.6
