The quilt patch titled Subject: mm/damon/core: avoid divide-by-zero from pseudo-moving window length calculation has been removed from the -mm tree. Its filename was mm-damon-core-avoid-divide-by-zero-from-pseudo-moving-window-length-calculation.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: SeongJae Park <sj@xxxxxxxxxx> Subject: mm/damon/core: avoid divide-by-zero from pseudo-moving window length calculation Date: Thu, 19 Oct 2023 19:49:24 +0000 When calculating the pseudo-moving access rate, DAMON 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. Note that this is a fix for a commit that not in the mainline but mm tree. Link: https://lkml.kernel.org/r/20231019194924.100347-6-sj@xxxxxxxxxx Fixes: ace30fb21af5 ("mm/damon/core: use pseudo-moving sum for nr_accesses_bp") Reported-by: Jakub Acs <acsjakub@xxxxxxxxx> Signed-off-by: SeongJae Park <sj@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/damon/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/damon/core.c~mm-damon-core-avoid-divide-by-zero-from-pseudo-moving-window-length-calculation +++ a/mm/damon/core.c @@ -1665,7 +1665,7 @@ void damon_update_region_access_rate(str * aggr_interval, owing to validation of damon_set_attrs(). */ if (attrs->sample_interval) - len_window = attrs->aggr_interval / attrs->sample_interval; + len_window = damon_max_nr_accesses(attrs); r->nr_accesses_bp = damon_moving_sum(r->nr_accesses_bp, r->last_nr_accesses * 10000, len_window, accessed ? 10000 : 0); _ Patches currently in -mm which might be from sj@xxxxxxxxxx are mm-damon-sysfs-remove-requested-targets-when-online-commit-inputs.patch