| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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| 2 | #include <linux/fs.h> |
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| 3 | |
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| 4 | #define DEVCG_ACC_MKNOD 1 |
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| 5 | #define DEVCG_ACC_READ 2 |
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| 6 | #define DEVCG_ACC_WRITE 4 |
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| 7 | #define DEVCG_ACC_MASK (DEVCG_ACC_MKNOD | DEVCG_ACC_READ | DEVCG_ACC_WRITE) |
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| 8 | |
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| 9 | #define DEVCG_DEV_BLOCK 1 |
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| 10 | #define DEVCG_DEV_CHAR 2 |
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| 11 | #define DEVCG_DEV_ALL 4 /* this represents all devices */ |
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| 12 | |
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| 13 | |
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| 14 | #if defined(CONFIG_CGROUP_DEVICE) || defined(CONFIG_CGROUP_BPF) |
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| 15 | int devcgroup_check_permission(short type, u32 major, u32 minor, |
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| 16 | short access); |
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| 17 | static inline int devcgroup_inode_permission(struct inode *inode, int mask) |
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| 18 | { |
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| 19 | short type, access = 0; |
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| 20 | |
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| 21 | if (likely(!S_ISBLK(inode->i_mode) && !S_ISCHR(inode->i_mode))) |
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| 22 | return 0; |
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| 23 | |
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| 24 | if (likely(!inode->i_rdev)) |
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| 25 | return 0; |
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| 26 | |
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| 27 | if (S_ISBLK(inode->i_mode)) |
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| 28 | type = DEVCG_DEV_BLOCK; |
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| 29 | else /* S_ISCHR by the test above */ |
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| 30 | type = DEVCG_DEV_CHAR; |
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| 31 | |
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| 32 | if (mask & MAY_WRITE) |
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| 33 | access |= DEVCG_ACC_WRITE; |
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| 34 | if (mask & MAY_READ) |
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| 35 | access |= DEVCG_ACC_READ; |
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| 36 | |
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| 37 | return devcgroup_check_permission(type, major: imajor(inode), minor: iminor(inode), |
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| 38 | access); |
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| 39 | } |
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| 40 | |
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| 41 | static inline int devcgroup_inode_mknod(int mode, dev_t dev) |
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| 42 | { |
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| 43 | short type; |
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| 44 | |
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| 45 | if (!S_ISBLK(mode) && !S_ISCHR(mode)) |
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| 46 | return 0; |
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| 47 | |
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| 48 | if (S_ISCHR(mode) && dev == WHITEOUT_DEV) |
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| 49 | return 0; |
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| 50 | |
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| 51 | if (S_ISBLK(mode)) |
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| 52 | type = DEVCG_DEV_BLOCK; |
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| 53 | else |
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| 54 | type = DEVCG_DEV_CHAR; |
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| 55 | |
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| 56 | return devcgroup_check_permission(type, MAJOR(dev), MINOR(dev), |
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| 57 | DEVCG_ACC_MKNOD); |
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| 58 | } |
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| 59 | |
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| 60 | #else |
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| 61 | static inline int devcgroup_check_permission(short type, u32 major, u32 minor, |
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| 62 | short access) |
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| 63 | { return 0; } |
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| 64 | static inline int devcgroup_inode_permission(struct inode *inode, int mask) |
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| 65 | { return 0; } |
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| 66 | static inline int devcgroup_inode_mknod(int mode, dev_t dev) |
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| 67 | { return 0; } |
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| 68 | #endif |
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| 69 | |
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