Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#include <linux/fs.h>
3
4#define DEVCG_ACC_MKNOD 1
5#define DEVCG_ACC_READ 2
6#define DEVCG_ACC_WRITE 4
7#define DEVCG_ACC_MASK (DEVCG_ACC_MKNOD | DEVCG_ACC_READ | DEVCG_ACC_WRITE)
8
9#define DEVCG_DEV_BLOCK 1
10#define DEVCG_DEV_CHAR 2
11#define DEVCG_DEV_ALL 4 /* this represents all devices */
12
13
14#if defined(CONFIG_CGROUP_DEVICE) || defined(CONFIG_CGROUP_BPF)
15int devcgroup_check_permission(short type, u32 major, u32 minor,
16 short access);
17static inline int devcgroup_inode_permission(struct inode *inode, int mask)
18{
19 short type, access = 0;
20
21 if (likely(!S_ISBLK(inode->i_mode) && !S_ISCHR(inode->i_mode)))
22 return 0;
23
24 if (likely(!inode->i_rdev))
25 return 0;
26
27 if (S_ISBLK(inode->i_mode))
28 type = DEVCG_DEV_BLOCK;
29 else /* S_ISCHR by the test above */
30 type = DEVCG_DEV_CHAR;
31
32 if (mask & MAY_WRITE)
33 access |= DEVCG_ACC_WRITE;
34 if (mask & MAY_READ)
35 access |= DEVCG_ACC_READ;
36
37 return devcgroup_check_permission(type, imajor(inode), iminor(inode),
38 access);
39}
40
41static inline int devcgroup_inode_mknod(int mode, dev_t dev)
42{
43 short type;
44
45 if (!S_ISBLK(mode) && !S_ISCHR(mode))
46 return 0;
47
48 if (S_ISCHR(mode) && dev == WHITEOUT_DEV)
49 return 0;
50
51 if (S_ISBLK(mode))
52 type = DEVCG_DEV_BLOCK;
53 else
54 type = DEVCG_DEV_CHAR;
55
56 return devcgroup_check_permission(type, MAJOR(dev), MINOR(dev),
57 DEVCG_ACC_MKNOD);
58}
59
60#else
61static inline int devcgroup_check_permission(short type, u32 major, u32 minor,
62 short access)
63{ return 0; }
64static inline int devcgroup_inode_permission(struct inode *inode, int mask)
65{ return 0; }
66static inline int devcgroup_inode_mknod(int mode, dev_t dev)
67{ return 0; }
68#endif