blob: 8762c3233a3d18402072084ad3ef502f10b5ce6f [file] [log] [blame]
.. SPDX-License-Identifier: GPL-2.0
.. _fs_kfuncs-header-label:
BPF filesystem kfuncs
BPF LSM programs need to access filesystem data from LSM hooks. The following
BPF kfuncs can be used to get these data.
* ``bpf_get_file_xattr()``
* ``bpf_get_fsverity_digest()``
To avoid recursions, these kfuncs follow the following rules:
1. These kfuncs are only permitted from BPF LSM function.
2. These kfuncs should not call into other LSM hooks, i.e. security_*(). For
example, ``bpf_get_file_xattr()`` does not use ``vfs_getxattr()``, because
the latter calls LSM hook ``security_inode_getxattr``.