[PATCH 4/4] selftests/mm: Add messages about test errors to the cow tests

[Mark Brown]

It is not sufficiently clear what the individual tests in the cow test
program are checking so add messages for the failure cases.

Suggested-by: David Hildenbrand <da...@redhat.com>
Signed-off-by: Mark Brown <broo...@kernel.org>
---
 tools/testing/selftests/mm/cow.c | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c
index 48fcf03aa4cd..29767e2afdd0 100644
--- a/tools/testing/selftests/mm/cow.c
+++ b/tools/testing/selftests/mm/cow.c
@@ -268,8 +268,10 @@ static void do_test_cow_in_parent(char *mem, size_t size, 
bool do_mprotect,
                 * fail because (a) harder to fix and (b) nobody really cares.
                 * Flag them as expected failure for now.
                 */
+               ksft_print_msg("Leak from parent into child\n");
                log_test_result(KSFT_XFAIL);
        } else {
+               ksft_print_msg("Leak from parent into child\n");
                log_test_result(KSFT_FAIL);
        }
 close_comm_pipes:
@@ -397,8 +399,10 @@ static void do_test_vmsplice_in_parent(char *mem, size_t 
size,
                 * fail because (a) harder to fix and (b) nobody really cares.
                 * Flag them as expected failure for now.
                 */
+               ksft_print_msg("Leak from child into parent\n");
                log_test_result(KSFT_XFAIL);
        } else {
+               ksft_print_msg("Leak from child into parent\n");
                log_test_result(KSFT_FAIL);
        }
 close_pipe:
@@ -570,10 +574,12 @@ static void do_test_iouring(char *mem, size_t size, bool 
use_fork)
        }
 
        /* Finally, check if we read what we expected. */
-       if (!memcmp(mem, tmp, size))
+       if (!memcmp(mem, tmp, size)) {
                log_test_result(KSFT_PASS);
-       else
+       } else {
+               ksft_print_msg("Longtom R/W pin is not reliable\n");
                log_test_result(KSFT_FAIL);
+       }
 
 quit_child:
        if (use_fork) {
@@ -725,10 +731,12 @@ static void do_test_ro_pin(char *mem, size_t size, enum 
ro_pin_test test,
                ksft_perror("PIN_LONGTERM_TEST_READ failed");
                log_test_result(KSFT_FAIL);
        } else {
-               if (!memcmp(mem, tmp, size))
+               if (!memcmp(mem, tmp, size)) {
                        log_test_result(KSFT_PASS);
-               else
+               } else {
+                       ksft_print_msg("Longterm R/O pin is not reliable\n");
                        log_test_result(KSFT_FAIL);
+               }
        }
 
        ret = ioctl(gup_fd, PIN_LONGTERM_TEST_STOP);
@@ -1417,10 +1425,12 @@ static void do_test_anon_thp_collapse(char *mem, size_t 
size,
        else
                ret = -EINVAL;
 
-       if (!ret)
+       if (!ret) {
                log_test_result(KSFT_PASS);
-       else
+       } else {
+               ksft_print_msg("Leak from parent into child\n");
                log_test_result(KSFT_FAIL);
+       }
 close_comm_pipes:
        close_comm_pipes(&comm_pipes);
 }
@@ -1528,10 +1538,12 @@ static void test_cow(char *mem, const char *smem, 
size_t size)
        memset(mem, 0xff, size);
 
        /* See if we still read the old values via the other mapping. */
-       if (!memcmp(smem, old, size))
+       if (!memcmp(smem, old, size)) {
                log_test_result(KSFT_PASS);
-       else
+       } else {
+               ksft_print_msg("Other mapping modified\n");
                log_test_result(KSFT_FAIL);
+       }
        free(old);
 }
 

-- 
2.39.5