v4.19.13 snapshot.
diff --git a/include/linux/device_cgroup.h b/include/linux/device_cgroup.h
new file mode 100644
index 0000000..8557efe
--- /dev/null
+++ b/include/linux/device_cgroup.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/fs.h>
+#include <linux/bpf-cgroup.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
+
+#if defined(CONFIG_CGROUP_DEVICE) || defined(CONFIG_CGROUP_BPF)
+static inline int devcgroup_check_permission(short type, u32 major, u32 minor,
+ short access)
+{
+ int rc = BPF_CGROUP_RUN_PROG_DEVICE_CGROUP(type, major, minor, access);
+
+ if (rc)
+ return -EPERM;
+
+ 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))
+ type = DEVCG_DEV_BLOCK;
+ else if (S_ISCHR(inode->i_mode))
+ type = DEVCG_DEV_CHAR;
+ else
+ return 0;
+
+ 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; }
+static inline int devcgroup_inode_mknod(int mode, dev_t dev)
+{ return 0; }
+#endif