[PATCH v6 0/8] Add printf attribute to kselftest functions

[Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>]

kselftest.h declares many variadic functions that can print some
formatted message while also executing selftest logic. These
declarations don't have any compiler mechanism to verify if passed
arguments are valid in comparison with format specifiers used in
printf() calls.

Attribute addition can make debugging easier, the code more consistent
and prevent mismatched or missing variables.

The first patch adds __printf() macro and applies it to all functions
in kselftest.h that use printf format specifiers. After compiling all
selftests using:
	make -C tools/testing/selftests
many instances of format specifier mismatching are exposed in the form
of -Wformat warnings.

Fix the mismatched format specifiers caught by __printf() attribute in
multiple tests.

Series is based on kselftests next branch.

Changelog v6:
- Add methodology notes to all patches.
- No functional changes in the patches.

Changelog v5:
- Mention in the cover letter what methodology was used to find the
  mismatched format specifiers.
- No functional changes in the patches.

Changelog v4:
- Fix patch 1/8 subject typo.
- Add Reinette's reviewed-by tags.
- Rebase onto new kselftest/next patches.

Changelog v3:
- Changed git signature from Wieczor-Retman Maciej to Maciej
  Wieczor-Retman.
- Added one review tag.
- Rebased onto updated kselftests next branch.

Changelog v2:
- Add review and fixes tags to patches.
- Add two patches with mismatch fixes.
- Fix missed attribute in selftests/kvm. (Andrew)
- Fix previously missed issues in selftests/mm (Ilpo)

[v5] https://lore.kernel.org/all/cover.1697012398.git.maciej.wieczor-retman@intel.com/
[v4] https://lore.kernel.org/all/cover.1696846568.git.maciej.wieczor-retman@intel.com/
[v3] https://lore.kernel.org/all/cover.1695373131.git.maciej.wieczor-retman@intel.com/
[v2] https://lore.kernel.org/all/cover.1693829810.git.maciej.wieczor-retman@intel.com/
[v1] https://lore.kernel.org/all/cover.1693216959.git.maciej.wieczor-retman@intel.com/

Maciej Wieczor-Retman (8):
  selftests: Add printf attribute to kselftest prints
  selftests/cachestat: Fix print_cachestat format
  selftests/openat2: Fix wrong format specifier
  selftests/pidfd: Fix ksft print formats
  selftests/sigaltstack: Fix wrong format specifier
  selftests/kvm: Replace attribute with macro
  selftests/mm: Substitute attribute with a macro
  selftests/resctrl: Fix wrong format specifier

 .../selftests/cachestat/test_cachestat.c       |  2 +-
 tools/testing/selftests/kselftest.h            | 18 ++++++++++--------
 .../testing/selftests/kvm/include/test_util.h  |  8 ++++----
 tools/testing/selftests/mm/mremap_test.c       |  2 +-
 tools/testing/selftests/mm/pkey-helpers.h      |  2 +-
 tools/testing/selftests/openat2/openat2_test.c |  2 +-
 .../selftests/pidfd/pidfd_fdinfo_test.c        |  2 +-
 tools/testing/selftests/pidfd/pidfd_test.c     | 12 ++++++------
 tools/testing/selftests/resctrl/cache.c        |  2 +-
 tools/testing/selftests/sigaltstack/sas.c      |  2 +-
 10 files changed, 27 insertions(+), 25 deletions(-)


base-commit: 2531f374f922e77ba51f24d1aa6fa11c7f4c36b8
-- 
2.42.0