commit 90091c367e74d5b58d9ebe979cc363f7468f58d3 upstream.
This patch fixes the stack-entropy.sh test to exit gracefully when the LKDTM is not available. Test will hang otherwise as reported in [1].
Applicability of this fix to other LTS kernels: - 4.14: No lkdtm selftest - 4.19: No lkdtm selftest - 5.4: No lkdtm selftests - 5.10: Inital selftest version introduced in 46d1a0f03d661 ("selftests/lkdtm: Add tests for LKDTM targets") is a single script which has the LKDTM availability check - 6.1: Fix applied
This patch applies cleanly to stable-5.15 tree. Updated test was executed in Qemu VM with different kernels: - CONFIG_LKDTM not enabled. Test finished with status SKIP. - CONFIG_LKDTM enabled. Test failed (but not hanged) with error 'Stack entropy is low'. - CONFIG_LKDTM enabled and randomize_kstack_offset=on boot argument provided. Test succeed.
[1] https://lore.kernel.org/lkml/2836f48a-d4e2-7f00-f06c-9f556fbd6332@linuxfound...