[PATCH] selftests/mm: Fixed incorrect buffer->mirror size in hmm2 double_map test

From: Donet Tom
Date: Fri Sep 27 2024 - 01:08:29 EST


The hmm2 double_map test was failing due to an incorrect
buffer->mirror size. The buffer->mirror size was 6, while buffer->ptr
size was 6 * PAGE_SIZE. The test failed because the kernel's
copy_to_user function was attempting to copy a 6 * PAGE_SIZE buffer
to buffer->mirror. Since the size of buffer->mirror was incorrect,
copy_to_user failed.

This patch corrects the buffer->mirror size to 6 * PAGE_SIZE.

Test Result without this patch
==============================
# RUN hmm2.hmm2_device_private.double_map ...
# hmm-tests.c:1680:double_map:Expected ret (-14) == 0 (0)
# double_map: Test terminated by assertion
# FAIL hmm2.hmm2_device_private.double_map
not ok 53 hmm2.hmm2_device_private.double_map

Test Result with this patch
===========================
# RUN hmm2.hmm2_device_private.double_map ...
# OK hmm2.hmm2_device_private.double_map
ok 53 hmm2.hmm2_device_private.double_map

Signed-off-by: Donet Tom <donettom@xxxxxxxxxxxxx>
---
tools/testing/selftests/mm/hmm-tests.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/mm/hmm-tests.c b/tools/testing/selftests/mm/hmm-tests.c
index d2cfc9b494a0..141bf63cbe05 100644
--- a/tools/testing/selftests/mm/hmm-tests.c
+++ b/tools/testing/selftests/mm/hmm-tests.c
@@ -1657,7 +1657,7 @@ TEST_F(hmm2, double_map)

buffer->fd = -1;
buffer->size = size;
- buffer->mirror = malloc(npages);
+ buffer->mirror = malloc(size);
ASSERT_NE(buffer->mirror, NULL);

/* Reserve a range of addresses. */
--
2.43.5