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.
Additionally, test_prctl_fork_exec() now uses exit(4) after a failed
execv() to clearly signal exec failures. 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")
Acked-by: David Hildenbrand <da...@redhat.com>
Co-developed-by: Donet Tom <donet...@linux.ibm.com>
Signed-off-by: Donet Tom <donet...@linux.ibm.com>
Signed-off-by: Aboorva Devarajan <aboor...@linux.ibm.com>
---
.../testing/selftests/mm/ksm_functional_tests.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c
b/tools/testing/selftests/mm/ksm_functional_tests.c
index 996dc6645570..534aa405cac7 100644
--- a/tools/testing/selftests/mm/ksm_functional_tests.c
+++ b/tools/testing/selftests/mm/ksm_functional_tests.c
@@ -512,14 +512,14 @@ static int test_child_ksm(void)
/* Test if KSM is enabled for the process. */
if (prctl(PR_GET_MEMORY_MERGE, 0, 0, 0, 0) != 1)
- return -1;
+ return 1;
/* Test if merge could really happen. */
map = __mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE,
KSM_MERGE_NONE);
if (map == MAP_MERGE_FAIL)
- return -2;
+ return 2;
else if (map == MAP_MERGE_SKIP)
- return -3;
+ return 3;
ksm_unmerge();
munmap(map, size);
@@ -528,12 +528,14 @@ static int test_child_ksm(void)
static void test_child_ksm_err(int status)
{
- if (status == -1)
+ if (status == 1)
ksft_test_result_fail("unexpected PR_GET_MEMORY_MERGE result in
child\n");
- else if (status == -2)
+ else if (status == 2)
ksft_test_result_fail("Merge in child failed\n");
- else if (status == -3)
+ else if (status == 3)
ksft_test_result_skip("Merge in child skipped\n");
+ else if (status == 4)
+ ksft_test_result_fail("Binary not found\n");
}
/* Verify that prctl ksm flag is inherited. */
@@ -606,7 +608,7 @@ static void test_prctl_fork_exec(void)
char *argv_for_program[] = { prg_name,
FORK_EXEC_CHILD_PRG_NAME, NULL };
execv(prg_name, argv_for_program);
- return;
+ exit(4);
}
if (waitpid(child_pid, &status, 0) > 0) {
--
2.47.1
