The bug is here: KUNIT_EXPECT_EQ(test, r->ar.start, start + i * expected_width); KUNIT_EXPECT_EQ(test, r->ar.end, end);
For the damon_for_each_region(), just like list_for_each_entry(), the list iterator 'drm_crtc' will point to a bogus position containing HEAD if the list is empty or no element is found. This case must be checked before any use of the iterator, otherwise it will lead to a invalid memory access.
To fix this bug, just mov two KUNIT_EXPECT_EQ() into the loop when found.
Cc: stable@vger.kernel.org Fixes: 044cd9750fe01 ("mm/damon/vaddr-test: split a test function having >1024 bytes frame size") Signed-off-by: Xiaomeng Tong xiam0nd.tong@gmail.com --- mm/damon/vaddr-test.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h index 6a1b9272ea12..98b7a9f54b35 100644 --- a/mm/damon/vaddr-test.h +++ b/mm/damon/vaddr-test.h @@ -281,14 +281,16 @@ static void damon_test_split_evenly_succ(struct kunit *test, KUNIT_EXPECT_EQ(test, damon_nr_regions(t), nr_pieces);
damon_for_each_region(r, t) { - if (i == nr_pieces - 1) + if (i == nr_pieces - 1) { + KUNIT_EXPECT_EQ(test, + r->ar.start, start + i * expected_width); + KUNIT_EXPECT_EQ(test, r->ar.end, end); break; + } KUNIT_EXPECT_EQ(test, r->ar.start, start + i++ * expected_width); KUNIT_EXPECT_EQ(test, r->ar.end, start + i * expected_width); } - KUNIT_EXPECT_EQ(test, r->ar.start, start + i * expected_width); - KUNIT_EXPECT_EQ(test, r->ar.end, end); damon_free_target(t); }