[PATCH v2 0/7] Add compatibility fixes for KVM selftests with non-glibc C libraries

[Aqib Faruqui <aqibaf@amazon.com>]

This patch series adds compatibility fixes for building and running KVM selftests with musl 
and other non-glibc implementations. The changes address missing function definitions, syscall 
numbers, macros, type definitions, and runtime compatibility issues that are otherwise handled 
by glibc.

The series includes both build-time compatibility fixes (missing definitions, type mismatches) 
and runtime fixes (stdbuf compatibility in mixed libc environments) to ensure KVM selftests 
work correctly across different C library implementations.

Changes in v2:
- Split pidfd patch into two separate commits
- Dropped PAGE_SIZE redefinition patch - will root cause warning separately
- Dropped __packed fallback patch - tools infrastructure already handles this correctly
- Dropped pthread_attr_setaffinity_np patch - maintainer provided solution


Aqib Faruqui (7):
  selftests/pidfd: Add architecture-specific fallback definitions for
    pidfd_open
  selftests: harness: Include pidfd.h to get syscall definitions from
    tools/
  selftests: kselftest: Add memfd_create syscall compatibility
  KVM: selftests: Add backtrace fallback
  rseq: selftests: Add non-glibc compatibility fixes
  selftests: Fix stdbuf compatibility in mixed libc environments
  selftests: kselftest: Add ulong typedef for non-glibc compatibility

 tools/testing/selftests/kselftest.h                    | 24 ++++++++++++++++++++++++
 tools/testing/selftests/kselftest/runner.sh            |  2 +-
 tools/testing/selftests/kselftest_harness.h            |  1 +
 tools/testing/selftests/kvm/lib/assert.c               | 10 +++++++++-
 tools/testing/selftests/kvm/lib/kvm_util.c             |  1 +
 tools/testing/selftests/pidfd/pidfd.h                  |  4 ++++
 tools/testing/selftests/rseq/rseq-x86-thread-pointer.h | 14 ++++++++++++++
 tools/testing/selftests/rseq/rseq.c                    |  8 ++++++++
 8 files changed, 62 insertions(+), 2 deletions(-)

-- 
2.47.3