1 files changed, 61 insertions, 29 deletions

diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index 01aaef1a77c5..81e2f6995adb 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -150,39 +150,29 @@ static int bpf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 	return 0;
 }
 
-static int bpf_mkobj_ops(struct inode *dir, struct dentry *dentry,
-			 umode_t mode, const struct inode_operations *iops)
+static int bpf_mkobj_ops(struct dentry *dentry, umode_t mode, void *raw,
+			 const struct inode_operations *iops)
 {
-	struct inode *inode;
-
-	inode = bpf_get_inode(dir->i_sb, dir, mode | S_IFREG);
+	struct inode *dir = dentry->d_parent->d_inode;
+	struct inode *inode = bpf_get_inode(dir->i_sb, dir, mode);
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
 	inode->i_op = iops;
-	inode->i_private = dentry->d_fsdata;
+	inode->i_private = raw;
 
 	bpf_dentry_finalize(dentry, inode, dir);
 	return 0;
 }
 
-static int bpf_mkobj(struct inode *dir, struct dentry *dentry, umode_t mode,
-		     dev_t devt)
+static int bpf_mkprog(struct dentry *dentry, umode_t mode, void *arg)
 {
-	enum bpf_type type = MINOR(devt);
-
-	if (MAJOR(devt) != UNNAMED_MAJOR || !S_ISREG(mode) ||
-	    dentry->d_fsdata == NULL)
-		return -EPERM;
+	return bpf_mkobj_ops(dentry, mode, arg, &bpf_prog_iops);
+}
 
-	switch (type) {
-	case BPF_TYPE_PROG:
-		return bpf_mkobj_ops(dir, dentry, mode, &bpf_prog_iops);
-	case BPF_TYPE_MAP:
-		return bpf_mkobj_ops(dir, dentry, mode, &bpf_map_iops);
-	default:
-		return -EPERM;
-	}
+static int bpf_mkmap(struct dentry *dentry, umode_t mode, void *arg)
+{
+	return bpf_mkobj_ops(dentry, mode, arg, &bpf_map_iops);
 }
 
 static struct dentry *
@@ -218,7 +208,6 @@ static int bpf_symlink(struct inode *dir, struct dentry *dentry,
 
 static const struct inode_operations bpf_dir_iops = {
 	.lookup		= bpf_lookup,
-	.mknod		= bpf_mkobj,
 	.mkdir		= bpf_mkdir,
 	.symlink	= bpf_symlink,
 	.rmdir		= simple_rmdir,
@@ -234,7 +223,6 @@ static int bpf_obj_do_pin(const struct filename *pathname, void *raw,
 	struct inode *dir;
 	struct path path;
 	umode_t mode;
-	dev_t devt;
 	int ret;
 
 	dentry = kern_path_create(AT_FDCWD, pathname->name, &path, 0);
@@ -242,9 +230,8 @@ static int bpf_obj_do_pin(const struct filename *pathname, void *raw,
 		return PTR_ERR(dentry);
 
 	mode = S_IFREG | ((S_IRUSR | S_IWUSR) & ~current_umask());
-	devt = MKDEV(UNNAMED_MAJOR, type);
 
-	ret = security_path_mknod(&path, dentry, mode, devt);
+	ret = security_path_mknod(&path, dentry, mode, 0);
 	if (ret)
 		goto out;
 
@@ -254,9 +241,16 @@ static int bpf_obj_do_pin(const struct filename *pathname, void *raw,
 		goto out;
 	}
 
-	dentry->d_fsdata = raw;
-	ret = vfs_mknod(dir, dentry, mode, devt);
-	dentry->d_fsdata = NULL;
+	switch (type) {
+	case BPF_TYPE_PROG:
+		ret = vfs_mkobj(dentry, mode, bpf_mkprog, raw);
+		break;
+	case BPF_TYPE_MAP:
+		ret = vfs_mkobj(dentry, mode, bpf_mkmap, raw);
+		break;
+	default:
+		ret = -EPERM;
+	}
 out:
 	done_path_create(&path, dentry);
 	return ret;
@@ -368,7 +362,45 @@ out:
 	putname(pname);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(bpf_obj_get_user);
+
+static struct bpf_prog *__get_prog_inode(struct inode *inode, enum bpf_prog_type type)
+{
+	struct bpf_prog *prog;
+	int ret = inode_permission(inode, MAY_READ | MAY_WRITE);
+	if (ret)
+		return ERR_PTR(ret);
+
+	if (inode->i_op == &bpf_map_iops)
+		return ERR_PTR(-EINVAL);
+	if (inode->i_op != &bpf_prog_iops)
+		return ERR_PTR(-EACCES);
+
+	prog = inode->i_private;
+
+	ret = security_bpf_prog(prog);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	if (!bpf_prog_get_ok(prog, &type, false))
+		return ERR_PTR(-EINVAL);
+
+	return bpf_prog_inc(prog);
+}
+
+struct bpf_prog *bpf_prog_get_type_path(const char *name, enum bpf_prog_type type)
+{
+	struct bpf_prog *prog;
+	struct path path;
+	int ret = kern_path(name, LOOKUP_FOLLOW, &path);
+	if (ret)
+		return ERR_PTR(ret);
+	prog = __get_prog_inode(d_backing_inode(path.dentry), type);
+	if (!IS_ERR(prog))
+		touch_atime(&path);
+	path_put(&path);
+	return prog;
+}
+EXPORT_SYMBOL(bpf_prog_get_type_path);
 
 static void bpf_evict_inode(struct inode *inode)
 {