[PATCH v5 0/2] fanotify: lift pidfd reporting restrictions

[AnonymeMeow <anonymemeow@gmail.com>]

The pidfd API now supports pidfds for tasks that are not thread group leaders,
but fanotify has not caught up yet. This patch set lifts that restriction and
allows fanotify to report pidfds referring to the event-generating thread.

Additionally, this patch set allows fanotify to hand out pidfds for reaped
tasks by registering the event pid with pidfs when pidfd reporting is
requested and dropping the pid_has_task() check before the pidfd_prepare()
call, as suggested by Christian.

Link: https://lore.kernel.org/lkml/20260528-schmuckvoll-heilen-garen-be77b4208671@brauner/
Link: https://lore.kernel.org/lkml/20260602-patzt-sturz-segen-f1f305d61b75@brauner/

Changes since v4:
 - Add a pidfs_register_pid_gfp() helper function to pass in custom flags.

v4: https://lore.kernel.org/lkml/20260603001516.26234-1-anonymemeow@gmail.com/

AnonymeMeow (2):
  fanotify: report thread pidfds for FAN_REPORT_TID
  fanotify: allow reporting pidfds for reaped tasks

 fs/notify/fanotify/fanotify.c      | 17 +++++++++------
 fs/notify/fanotify/fanotify_user.c | 33 +++++++-----------------------
 fs/pidfs.c                         | 10 +++++----
 include/linux/pidfs.h              | 18 +++++++++++++++-
 4 files changed, 41 insertions(+), 37 deletions(-)

-- 
2.54.0