Re: [PATCH v4 0/7] ioctl()-based API to query VMAs from /proc/<pid>/maps

[Andrew Morton <akpm@linux-foundation.org>]

(Please cc Alexey on procfs changes)

On Tue, 11 Jun 2024 04:00:48 -0700 Andrii Nakryiko <andrii@kernel.org> wrote:

> Implement binary ioctl()-based interface to /proc/<pid>/maps file to allow
> applications to query VMA information more efficiently than reading *all* VMAs
> nonselectively through text-based interface of /proc/<pid>/maps file.

Looks nice but I'll await further reviewer input.

> 
> ...
>
>  Documentation/filesystems/proc.rst          |   9 +
>  fs/proc/task_mmu.c                          | 366 +++++++++++--
>  include/uapi/linux/fs.h                     | 156 +++++-
>  tools/include/uapi/linux/fs.h               | 550 ++++++++++++++++++++
>  tools/testing/selftests/bpf/.gitignore      |   1 +
>  tools/testing/selftests/bpf/Makefile        |   2 +-
>  tools/testing/selftests/bpf/procfs_query.c  | 386 ++++++++++++++
>  tools/testing/selftests/bpf/test_progs.c    |   3 +
>  tools/testing/selftests/bpf/test_progs.h    |   2 +
>  tools/testing/selftests/bpf/trace_helpers.c | 104 +++-
>  10 files changed, 1508 insertions(+), 71 deletions(-)
>  create mode 100644 tools/include/uapi/linux/fs.h
>  create mode 100644 tools/testing/selftests/bpf/procfs_query.c

Should the selftests be under bpf/?  This is a procfs feature which
could be used by many things apart from bpf and it really isn't a bpf
thing at all.  Wouldn't tools/testing/selftests/proc/ be a more
appropriate place?