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 additional 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 v10: - Check pid_alive() to avoid potential errors. Differences from v9: - Fix the boundary check of computing page_shift. - Rewording the reason of checking and returning the same task. Differences from v8: - Fix uninitialized variable. - Avoid redundant work of getting task from pid. - Change format string to use %u instead of %d. - Use the value of page_shift to compute correct offset in bpf_iter_vm_offset.c. Differences from v7: - Travel the tasks of a process through task_group linked list instead of traveling through the whole namespace. Differences from v6: - Add part 5 to make bpftool show the value of parameters. - Change of wording of show_fdinfo() to show pid or tid instead of always pid. - Simplify error handling and naming of test cases. Differences from v5: - Use user-space tid/pid terminologies in bpf_iter_link_info and bpf_link_info. - Fix reference count - Merge all variants to one 'u32 pid' in internal structs. (bpf_iter_aux_info and bpf_iter_seq_task_common) - Compare the result of get_uprobe_offset() with the implementation with the vma iterators. - Implement show_fdinfo. Differences from v4: - Remove 'type' from bpf_iter_link_info and bpf_link_info. v10: https://lore.kernel.org/all/20220831181039.2680134-1-kuifeng@xxxxxx/ v9: https://lore.kernel.org/bpf/20220829192317.486946-1-kuifeng@xxxxxx/ v8: https://lore.kernel.org/bpf/20220829192317.486946-1-kuifeng@xxxxxx/ v7: https://lore.kernel.org/bpf/20220826003712.2810158-1-kuifeng@xxxxxx/ v6: https://lore.kernel.org/bpf/20220819220927.3409575-1-kuifeng@xxxxxx/ v5: https://lore.kernel.org/bpf/20220811001654.1316689-1-kuifeng@xxxxxx/ v4: https://lore.kernel.org/bpf/20220809195429.1043220-1-kuifeng@xxxxxx/ v3: https://lore.kernel.org/bpf/20220809063501.667610-1-kuifeng@xxxxxx/ v2: https://lore.kernel.org/bpf/20220801232649.2306614-1-kuifeng@xxxxxx/ v1: https://lore.kernel.org/bpf/20220726051713.840431-1-kuifeng@xxxxxx/ Kui-Feng Lee (5): bpf: Parameterize task iterators. bpf: Handle bpf_link_info for the parameterized task BPF iterators. bpf: Handle show_fdinfo for the parameterized task BPF iterators selftests/bpf: Test parameterized task BPF iterators. bpftool: Show parameters of BPF task iterators. include/linux/bpf.h | 25 ++ include/uapi/linux/bpf.h | 10 + kernel/bpf/task_iter.c | 228 ++++++++++++-- tools/bpf/bpftool/link.c | 19 ++ tools/include/uapi/linux/bpf.h | 10 + .../selftests/bpf/prog_tests/bpf_iter.c | 282 ++++++++++++++++-- .../selftests/bpf/prog_tests/btf_dump.c | 2 +- .../selftests/bpf/progs/bpf_iter_task.c | 9 + .../selftests/bpf/progs/bpf_iter_task_file.c | 9 +- .../selftests/bpf/progs/bpf_iter_task_vma.c | 7 +- .../selftests/bpf/progs/bpf_iter_vma_offset.c | 37 +++ 11 files changed, 592 insertions(+), 46 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_vma_offset.c -- 2.30.2
