Commit 5e06ad59 authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

mm/damon/core-test: test max_nr_accesses overflow caused divide-by-zero 

Commit 35f5d941 ("mm/damon: implement a function for max nr_accesses
safe calculation") has fixed an overflow bug that could cause
divide-by-zero.  Add a kunit test for the bug to ensure similar bugs are
not introduced again.

Link: https://lkml.kernel.org/r/20231213190338.54146-3-sj@kernel.org


Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 6ad59a38

mm/damon/core-test.h

+11 −0
Original line number Diff line number Diff line
@@ -302,6 +302,16 @@ static void damon_test_set_regions(struct kunit *test) 
	damon_destroy_target(t);

}



static void damon_test_nr_accesses_to_accesses_bp(struct kunit *test)

{

	struct damon_attrs attrs = {

		.sample_interval = 10,

		.aggr_interval = ((unsigned long)UINT_MAX + 1) * 10

	};



	KUNIT_EXPECT_EQ(test, damon_nr_accesses_to_accesses_bp(123, &attrs), 0);

}



static void damon_test_update_monitoring_result(struct kunit *test)

{

	struct damon_attrs old_attrs = {
@@ -487,6 +497,7 @@ static struct kunit_case damon_test_cases[] = { 
	KUNIT_CASE(damon_test_split_regions_of),

	KUNIT_CASE(damon_test_ops_registration),

	KUNIT_CASE(damon_test_set_regions),

	KUNIT_CASE(damon_test_nr_accesses_to_accesses_bp),

	KUNIT_CASE(damon_test_update_monitoring_result),

	KUNIT_CASE(damon_test_set_attrs),

	KUNIT_CASE(damon_test_moving_sum),