Hello Greg, Shuah, While testing 4.4.y and 4.9.y LTS kernels with latest kselftest, we found a couple more test failures due to test-kernel mismatch: 1. firmware tests: - linux 4.5 [1] and 4.10 [2] added a few updates to tests, and related updates to lib/test_firmware.c to improve the tests. Stable-4.4 misses these patches to lib/test_firmware.c. Stable 4.9 misses the second update. 2. Bitmap test - test got added in 4.5, fails if test_bitmap.ko isn't present. 3. 'seccomp ptrace hole closure' patches got added in 4.7 [3] - feature and test together. - This one also seems like a security hole being closed, and the 'feature' could be a candidate for stable backports, but Arnd tried that, and it was quite non-trivial. So perhaps we'll need some help from the subsystem developers here. For all the 3 listed above, we will try and update the tests to gracefully exit. 4. bpf tests: These seem to have build failures in mainline as well - I also tried to build kselftest-next, but a simple 'make -C tools/testing/selftests/bpf' seems to error out. Are there any special instructions to build these? [I tried x86_64, arm64 cross-compile on x86_64] I will also individually request subsystem authors / mailing lists for each of these towards help in improving these tests if required, but wanted to use this thread as a converging point. Thanks and Best regards, Sumit. [1]: https://lkml.org/lkml/2015/12/8/816 Patches added via [1]: eb910947c82f (test: firmware_class: add asynchronous request trigger) be4a1326d12c (test: firmware_class: use kstrndup() where appropriate) 47e0bbb7fa98 (test: firmware_class: report errors properly on failure) [2]: https://lkml.org/lkml/2017/1/23/440 Patch added via [2]: 061132d2b9c9 (test_firmware: add test custom fallback trigger) [3]: https://lkml.org/lkml/2016/6/9/627