[PATCH bpf-next v8 0/5] Attach a cookie to a tracing program.

[Kui-Feng Lee <kuifeng@fb.com>]

Allow users to attach a 64-bits cookie to a bpf_link of fentry, fexit,
or fmod_ret.

This patchset includes several major changes.

 - Define struct bpf_tramp_links to replace bpf_tramp_prog.
   struct bpf_tramp_links collects bpf_links of a trampoline

 - Generate a trampoline to call bpf_progs of given bpf_links.

 - Trampolines always set/reset bpf_run_ctx before/after
   calling/leaving a tracing program.

 - Attach a cookie to a bpf_link of fentry/fexit/fmod_ret/lsm.  The
   value will be available when running the associated bpf_prog.

Th major differences from v6:

 - bpf_link_create() can create links of BPF_LSM_MAC attach type.

 - Add a test for lsm.

 - Add function proto of bpf_get_attach_cookie() for lsm.

 - Check BPF_LSM_MAC in bpf_prog_has_trampoline().

 - Adapt to the changes of LINK_CREATE made by Andrii.

The major differences from v7:

 - Change stack_size instead of pushing/popping run_ctx.

 - Move cookie to bpf_tramp_link from bpf_tracing_link..

v1: https://lore.kernel.org/all/20220126214809.3868787-1-kuifeng@fb.com/
v2: https://lore.kernel.org/bpf/20220316004231.1103318-1-kuifeng@fb.com/
v3: https://lore.kernel.org/bpf/20220407192552.2343076-1-kuifeng@fb.com/
v4: https://lore.kernel.org/bpf/20220411173429.4139609-1-kuifeng@fb.com/
v5: https://lore.kernel.org/bpf/20220412165555.4146407-1-kuifeng@fb.com/
v6: https://lore.kernel.org/bpf/20220416042940.656344-1-kuifeng@fb.com/
v7: https://lore.kernel.org/bpf/20220508032117.2783209-1-kuifeng@fb.com/

Kui-Feng Lee (5):
  bpf, x86: Generate trampolines from bpf_tramp_links
  bpf, x86: Create bpf_tramp_run_ctx on the caller thread's stack
  bpf, x86: Attach a cookie to fentry/fexit/fmod_ret/lsm.
  libbpf: Assign cookies to links in libbpf.
  selftest/bpf: The test cses of BPF cookie for
    fentry/fexit/fmod_ret/lsm.

 arch/x86/net/bpf_jit_comp.c                   |  76 ++++++++-----
 include/linux/bpf.h                           |  54 +++++++---
 include/linux/bpf_types.h                     |   1 +
 include/uapi/linux/bpf.h                      |  10 ++
 kernel/bpf/bpf_lsm.c                          |  17 +++
 kernel/bpf/bpf_struct_ops.c                   |  71 +++++++++----
 kernel/bpf/syscall.c                          |  42 ++++----
 kernel/bpf/trampoline.c                       | 100 +++++++++++-------
 kernel/trace/bpf_trace.c                      |  17 +++
 net/bpf/bpf_dummy_struct_ops.c                |  24 ++++-
 tools/bpf/bpftool/link.c                      |   1 +
 tools/include/uapi/linux/bpf.h                |  10 ++
 tools/lib/bpf/bpf.c                           |   8 ++
 tools/lib/bpf/bpf.h                           |   3 +
 tools/lib/bpf/libbpf.c                        |  19 +++-
 tools/lib/bpf/libbpf.h                        |  12 +++
 tools/lib/bpf/libbpf.map                      |   1 +
 .../selftests/bpf/prog_tests/bpf_cookie.c     |  89 ++++++++++++++++
 .../selftests/bpf/progs/test_bpf_cookie.c     |  52 +++++++--
 19 files changed, 469 insertions(+), 138 deletions(-)

-- 
2.30.2