fs_kfuncs.rst

 1.. SPDX-License-Identifier: GPL-2.0
 2
 3.. _fs_kfuncs-header-label:
 4
 5=====================
 6BPF filesystem kfuncs
 7=====================
 8
 9BPF LSM programs need to access filesystem data from LSM hooks. The following
10BPF kfuncs can be used to get these data.
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12 * ``bpf_get_file_xattr()``
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14 * ``bpf_get_fsverity_digest()``
15
16To avoid recursions, these kfuncs follow the following rules:
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181. These kfuncs are only permitted from BPF LSM function.
192. These kfuncs should not call into other LSM hooks, i.e. security_*(). For
20   example, ``bpf_get_file_xattr()`` does not use ``vfs_getxattr()``, because
21   the latter calls LSM hook ``security_inode_getxattr``.