damon_ctx->passed_sample_intervals and damon_ctx->next_*_sis are unsigned long. Those are compared in kdamond_fn() using normal comparison operators. It is unsafe from overflow. Use time_after_eq(), which is safe from overflows when correctly used, instead. Signed-off-by: SeongJae Park --- mm/damon/core.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/mm/damon/core.c b/mm/damon/core.c index 4ede733a94cc0..cd2d7a8e3fe92 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -2915,7 +2915,8 @@ static int kdamond_fn(void *data) if (ctx->ops.check_accesses) max_nr_accesses = ctx->ops.check_accesses(ctx); - if (ctx->passed_sample_intervals >= next_aggregation_sis) { + if (time_after_eq(ctx->passed_sample_intervals, + next_aggregation_sis)) { kdamond_merge_regions(ctx, max_nr_accesses / 10, sz_limit); @@ -2935,10 +2936,12 @@ static int kdamond_fn(void *data) sample_interval = ctx->attrs.sample_interval ? ctx->attrs.sample_interval : 1; - if (ctx->passed_sample_intervals >= next_aggregation_sis) { + if (time_after_eq(ctx->passed_sample_intervals, + next_aggregation_sis)) { if (ctx->attrs.intervals_goal.aggrs && - ctx->passed_sample_intervals >= - ctx->next_intervals_tune_sis) { + time_after_eq( + ctx->passed_sample_intervals, + ctx->next_intervals_tune_sis)) { /* * ctx->next_aggregation_sis might be updated * from kdamond_call(). In the case, @@ -2972,7 +2975,8 @@ static int kdamond_fn(void *data) kdamond_split_regions(ctx); } - if (ctx->passed_sample_intervals >= next_ops_update_sis) { + if (time_after_eq(ctx->passed_sample_intervals, + next_ops_update_sis)) { ctx->next_ops_update_sis = next_ops_update_sis + ctx->attrs.ops_update_interval / sample_interval; -- 2.47.3