[PATCH bpf-next v4 0/3] Parameterize task iterators.

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

Allow creating an iterator that loops through resources of one task/thread.

People could only create iterators to loop through all resources of
files, vma, and tasks in the system, even though they were interested in only the
resources of a specific task or process.  Passing the addintional
parameters, people can now create an iterator to go through all
resources or only the resources of a task.

Major Changes:

 - Add new parameters in bpf_iter_link_info to indicate to go through
   all tasks or to go through a specific task.

 - Change the implementations of BPF iterators of vma, files, and
   tasks to allow going through only the resources of a specific task.

 - Provide the arguments of parameterized task iterators in
   bpf_link_info.

Differences from v3:

 - Fix the test case bpf_iter/test

Differences from v2:

 - Supports tid, tgid, and pidfd.

 - Change 'type' from __u8 to enum bpf_task_iter_type.

v3: https://lore.kernel.org/bpf/20220809063501.667610-1-kuifeng@fb.com/
v2: https://lore.kernel.org/bpf/20220801232649.2306614-1-kuifeng@fb.com/
v1: https://lore.kernel.org/bpf/20220726051713.840431-1-kuifeng@fb.com/

Kui-Feng Lee (3):
  bpf: Parameterize task iterators.
  bpf: Handle bpf_link_info for the parameterized task BPF iterators.
  selftests/bpf: Test parameterized task BPF iterators.

 include/linux/bpf.h                           |   8 +
 include/uapi/linux/bpf.h                      |  43 ++++
 kernel/bpf/task_iter.c                        | 153 +++++++++++--
 tools/include/uapi/linux/bpf.h                |  43 ++++
 .../selftests/bpf/prog_tests/bpf_iter.c       | 208 ++++++++++++++++--
 .../selftests/bpf/prog_tests/btf_dump.c       |   2 +-
 .../selftests/bpf/progs/bpf_iter_task.c       |   9 +
 .../selftests/bpf/progs/bpf_iter_task_file.c  |   7 +
 .../selftests/bpf/progs/bpf_iter_task_vma.c   |   6 +-
 9 files changed, 430 insertions(+), 49 deletions(-)

-- 
2.30.2