Documentation/bpf/fs_kfuncs.rst

Source file repositories/reference/linux-study-clean/Documentation/bpf/fs_kfuncs.rst

File Facts

System
Linux kernel
Corpus path
Documentation/bpf/fs_kfuncs.rst
Extension
.rst
Size
651 bytes
Lines
22
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

.. 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``.

Annotation

Implementation Notes