When monitoring attributes are changed, DAMON updates access rate of the
monitoring results accordingly. For that, it divides some values by the
maximum nr_accesses. However, due to the type of the related variables,
simple division-based calculation of the divisor can return zero. As a
result, divide-by-zero is possible. Fix it by using
damon_max_nr_accesses(), which handles the case.
Reported-by: Jakub Acs <acsjakub@xxxxxxxxx>
Fixes: 2f5bef5a590b ("mm/damon/core: update monitoring results for new monitoring attributes")
Cc: <stable@xxxxxxxxxxxxxxx> # 6.3.x
Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
---
mm/damon/core.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/mm/damon/core.c b/mm/damon/core.c
index 9f4f7c378cf3..e194c8075235 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -500,20 +500,14 @@ static unsigned int damon_age_for_new_attrs(unsigned int age,
static unsigned int damon_accesses_bp_to_nr_accesses(
unsigned int accesses_bp, struct damon_attrs *attrs)
{
- unsigned int max_nr_accesses =
- attrs->aggr_interval / attrs->sample_interval;
-
- return accesses_bp * max_nr_accesses / 10000;
+ return accesses_bp * damon_max_nr_accesses(attrs) / 10000;
}
/* convert nr_accesses to access ratio in bp (per 10,000) */
static unsigned int damon_nr_accesses_to_accesses_bp(
unsigned int nr_accesses, struct damon_attrs *attrs)
{
- unsigned int max_nr_accesses =
- attrs->aggr_interval / attrs->sample_interval;
-
- return nr_accesses * 10000 / max_nr_accesses;
+ return nr_accesses * 10000 / damon_max_nr_accesses(attrs);
}
static unsigned int damon_nr_accesses_for_new_attrs(unsigned int nr_accesses,
--
2.34.1
