kernel/bpf/inode.c

Source file repositories/reference/linux-study-clean/kernel/bpf/inode.c

File Facts

System
Linux kernel
Corpus path
kernel/bpf/inode.c
Extension
.c
Size
29717 bytes
Lines
1320
Domain
Core OS
Bucket
Scheduler, Processes, Timers, Sync, And Syscalls
Inferred role
Core OS: operation-table or driver-model contract
Status
pattern implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

static const struct file_operations bpffs_map_fops = {
	.open		= bpffs_map_open,
	.read		= seq_read,
	.release	= bpffs_map_release,
};

static int bpffs_obj_open(struct inode *inode, struct file *file)
{
	return -EIO;
}

static const struct file_operations bpffs_obj_fops = {
	.open		= bpffs_obj_open,
};

static int bpf_mkobj_ops(struct dentry *dentry, umode_t mode, void *raw,
			 const struct inode_operations *iops,
			 const struct file_operations *fops)
{
	struct inode *dir = dentry->d_parent->d_inode;
	struct inode *inode;
	int ret;

	inode = bpf_get_inode(dir->i_sb, dir, mode);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	ret = security_inode_init_security(inode, dir, &dentry->d_name,
					   bpf_fs_initxattrs, NULL);
	if (ret && ret != -EOPNOTSUPP) {
		iput(inode);
		return ret;
	}

	inode->i_op = iops;
	inode->i_fop = fops;
	inode->i_private = raw;

	bpf_dentry_finalize(dentry, inode, dir);
	return 0;
}

static int bpf_mkprog(struct dentry *dentry, umode_t mode, void *arg)
{
	return bpf_mkobj_ops(dentry, mode, arg, &bpf_prog_iops,
			     &bpffs_obj_fops);
}

static int bpf_mkmap(struct dentry *dentry, umode_t mode, void *arg)
{
	struct bpf_map *map = arg;

	return bpf_mkobj_ops(dentry, mode, arg, &bpf_map_iops,
			     bpf_map_support_seq_show(map) ?
			     &bpffs_map_fops : &bpffs_obj_fops);
}

static int bpf_mklink(struct dentry *dentry, umode_t mode, void *arg)
{
	struct bpf_link *link = arg;

	return bpf_mkobj_ops(dentry, mode, arg, &bpf_link_iops,
			     bpf_link_is_iter(link) ?
			     &bpf_iter_fops : &bpffs_obj_fops);
}

static struct dentry *
bpf_lookup(struct inode *dir, struct dentry *dentry, unsigned flags)
{
	/* Dots in names (e.g. "/sys/fs/bpf/foo.bar") are reserved for future
	 * extensions. That allows popoulate_bpffs() create special files.
	 */
	if ((dir->i_mode & S_IALLUGO) &&
	    strchr(dentry->d_name.name, '.'))
		return ERR_PTR(-EPERM);

	return simple_lookup(dir, dentry, flags);
}

static int bpf_symlink(struct mnt_idmap *idmap, struct inode *dir,
		       struct dentry *dentry, const char *target)
{
	struct inode *inode;
	char *link;
	int ret;

	link = kstrdup(target, GFP_KERNEL_ACCOUNT | __GFP_NOWARN);
	if (!link)
		return -ENOMEM;

Annotation

Implementation Notes