On 03.07.25 08:06, Aboorva Devarajan wrote:
In ksm_functional_tests, test_child_ksm() returned negative values to indicate errors. However, when passed to exit(), these were interpreted as large unsigned values (e.g, -2 became 254), leading to incorrect handling in the parent process. As a result, some tests appeared to be skipped or silently failed.This patch changes test_child_ksm() to return positive error codes (1, 2, 3) and updates test_child_ksm_err() to interpret them correctly. This ensures the parent accurately detects and reports child process failures. -------------- Before patch: -------------- - [RUN] test_unmerge ok 1 Pages were unmerged ... - [RUN] test_prctl_fork - No pages got merged - [RUN] test_prctl_fork_exec ok 7 PR_SET_MEMORY_MERGE value is inherited ... Bail out! 1 out of 8 tests failed - Planned tests != run tests (9 != 8) - Totals: pass:7 fail:1 xfail:0 xpass:0 skip:0 error:0 -------------- After patch: -------------- - [RUN] test_unmerge ok 1 Pages were unmerged ... - [RUN] test_prctl_fork - No pages got merged not ok 7 Merge in child failed - [RUN] test_prctl_fork_exec ok 8 PR_SET_MEMORY_MERGE value is inherited ... Bail out! 2 out of 9 tests failed - Totals: pass:7 fail:2 xfail:0 xpass:0 skip:0 error:0 Fixes: 6c47de3be3a0 ("selftest/mm: ksm_functional_tests: extend test case for ksm fork/exec") Signed-off-by: Aboorva Devarajan <[email protected]>
Surprising, but seems to be the right thing to do. Acked-by: David Hildenbrand <[email protected]> -- Cheers, David / dhildenb

