[v4,bpf-next,0/3] bpf: introduce new VFS based BPF kfuncs

Message

Matt Bobrowski July 31, 2024, 11:08 a.m. UTC

G'day!

A respin based off v3, which can be found here [0]. Original
motivations for introducing this suite of BPF kfuncs can be found here
[1].

The primary difference in this version of the patch series is that the
suite of VFS related BPF kfuncs added can be used from both sleepable
and non-sleepable BPF LSM program types. IOW, the KF_SLEEPABLE
annotation has been removed from all of them.

Changes sinve v3:

* KF_SLEEPABLE annotation has been dropped from all newly introduced
  VFS related BPF kfuncs. This includes bpf_get_task_exe_file(),
  bpf_put_file(), and bpf_path_d_path(). Both negative and positive
  selftests backing these new BPF kfuncs have also been updated
  accordingly.

* buf__sz conditional in bpf_path_d_path() has been updated from
  buf__sz <= 0, to !buf__sz.

* Syntax issues as reported so here [2] have been corrected.

[0] https://lore.kernel.org/bpf/[e-mail]/
[1] https://lore.kernel.org/bpf/[e-mail]/#t
[2] https://netdev.bots.linux.dev/static/nipa/874023/13742510/checkpatch/stdout

Matt Bobrowski (3):
  bpf: introduce new VFS based BPF kfuncs
  selftests/bpf: add negative tests for new VFS based BPF kfuncs
  selftests/bpf: add positive tests for new VFS based BPF kfuncs

 fs/Makefile                                   |   1 +
 fs/bpf_fs_kfuncs.c                            | 127 ++++++++++++++
 .../testing/selftests/bpf/bpf_experimental.h  |  26 +++
 .../selftests/bpf/prog_tests/verifier.c       |   4 +
 .../selftests/bpf/progs/verifier_vfs_accept.c |  85 +++++++++
 .../selftests/bpf/progs/verifier_vfs_reject.c | 161 ++++++++++++++++++
 6 files changed, 404 insertions(+)
 create mode 100644 fs/bpf_fs_kfuncs.c
 create mode 100644 tools/testing/selftests/bpf/progs/verifier_vfs_accept.c
 create mode 100644 tools/testing/selftests/bpf/progs/verifier_vfs_reject.c