[PATCHSET v6] Inherited restrictions and BPF filtering for io_uring

[Jens Axboe <axboe@kernel.dk>]

Hi,

Followup to v5 here:

https://lore.kernel.org/io-uring/20260118172328.1067592-1-axboe@kernel.dk/

Mostly just addressing a bit of feedback, feature wise this is all the
same as before. For details on the patches, see the v5 posting linked
above. For details on the changes, see the changes section below.

Kernel branch can be found here:

https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux.git/log/?h=io_uring-bpf-restrictions.3

and a liburing branch with support helpers, man page, and a fairly
substantial test case can be found here:

https://git.kernel.org/pub/scm/linux/kernel/git/axboe/liburing.git/log/?h=bpf-restrictions

Feedback welcome!

Changes since v5:
- Disallow setting or appending filters for no_new_privs, unless the
  user is also CAP_SYS_ADMIN (Aleksa)
- Add support for filtering of IORING_OP_OPENAT/OPENAT2, in terms of
  being able to deny certain resolve or creation flags.
- Change layout of io_uring_bpf_ctx slightly, for easier/faster clearing
  of unused members.
- Expand liburing test cases to cover both the no_new_privs situation,
  and testing the OPENAT/OPENAT2 filters.

 include/linux/io_uring.h                 |  14 +-
 include/linux/io_uring_types.h           |  13 +
 include/linux/sched.h                    |   1 +
 include/uapi/linux/io_uring.h            |  10 +
 include/uapi/linux/io_uring/bpf_filter.h |  62 ++++
 io_uring/Kconfig                         |   5 +
 io_uring/Makefile                        |   1 +
 io_uring/bpf_filter.c                    | 436 +++++++++++++++++++++++
 io_uring/bpf_filter.h                    |  48 +++
 io_uring/io_uring.c                      |  48 +++
 io_uring/io_uring.h                      |   1 +
 io_uring/net.c                           |   9 +
 io_uring/net.h                           |   6 +
 io_uring/openclose.c                     |   9 +
 io_uring/openclose.h                     |   3 +
 io_uring/register.c                      |  91 +++++
 io_uring/tctx.c                          |  42 ++-
 kernel/fork.c                            |   5 +
 18 files changed, 794 insertions(+), 10 deletions(-)

-- 
Jens Axboe