[PATCH bpf-next v2 0/3] selftests/bpf: fix for veristat file/prog filters processing

At the moment veristat filtering behaves unexpectedly for the
following filter expression:

  -f !file/prog

The expression rejects all programs with name 'prog', and all programs
in a file with name 'file'. Fix the expression to exclude only a
program 'prog' from a file 'file', also add a set of tests to exercise
filtering logic.

Changelog:
v1 -> v2:
- added fixes tag for patch #1 (bot+bpf-ci);
- extended test cases for '!*foo*' and '*foo*' filters in patch #2
  (bot+bpf-ci);
- added patch #3, replacing direct read() calls with calls to
  read_output(), guaranteeing input buffer null termination
  (bot+bpf-ci).

v1: https://lore.kernel.org/bpf/[email protected]/
---
Eduard Zingerman (3):
      selftests/bpf: fix for veristat file/prog filters processing
      selftests/bpf: exercise veristat filtering logic in a selftest
      selftests/bpf: guarantee zero termination for veristat test buffers

 .../selftests/bpf/prog_tests/test_veristat.c       | 113 +++++++++++++++++++--
 tools/testing/selftests/bpf/progs/veristat_bar.c   |   3 +
 tools/testing/selftests/bpf/progs/veristat_foo.c   |  31 ++++++
 tools/testing/selftests/bpf/veristat.c             |  76 +++++++++-----
 4 files changed, 190 insertions(+), 33 deletions(-)
---
base-commit: d114bb98936770c501c958bf2bc5fb6b7c0bad7b
change-id: 20260811-veristat-filter-fix-920cff2a288a