From: Ayush Jain <ayush.jain3@xxxxxxx> commit 65294de30cb8bc7659e445f7be2846af9ed35499 upstream. A missing break in kms_tests leads to kselftest hang when the parameter -s is used. In current code flow because of missing break in -s, -t parses args spilled from -s and as -t accepts only valid values as 0,1 so any arg in -s >1 or <0, gets in ksm_test failure This went undetected since, before the addition of option -t, the next case -M would immediately break out of the switch statement but that is no longer the case Add the missing break statement. ----Before---- ./ksm_tests -H -s 100 Invalid merge type ----After---- ./ksm_tests -H -s 100 Number of normal pages: 0 Number of huge pages: 50 Total size: 100 MiB Total time: 0.401732682 s Average speed: 248.922 MiB/s Link: https://lkml.kernel.org/r/20230728163952.4634-1-ayush.jain3@xxxxxxx Fixes: 07115fcc15b4 ("selftests/mm: add new selftests for KSM") Signed-off-by: Ayush Jain <ayush.jain3@xxxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Cc: Stefan Roesch <shr@xxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/mm/ksm_tests.c | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/testing/selftests/mm/ksm_tests.c b/tools/testing/selftests/mm/ksm_tests.c index 435acebdc325..380b691d3eb9 100644 --- a/tools/testing/selftests/mm/ksm_tests.c +++ b/tools/testing/selftests/mm/ksm_tests.c @@ -831,6 +831,7 @@ int main(int argc, char *argv[]) printf("Size must be greater than 0\n"); return KSFT_FAIL; } + break; case 't': { int tmp = atoi(optarg); -- 2.41.0