[merged mm-stable] mm-damon-core-disallow-probe_hits-overflow-on-attrs-only-monitoring.patch removed from -mm tree

The quilt patch titled
     Subject: mm/damon/core: disallow probe_hits overflow on attrs only monitoring
has been removed from the -mm tree.  Its filename was
     mm-damon-core-disallow-probe_hits-overflow-on-attrs-only-monitoring.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: SJ Park <[email protected]>
Subject: mm/damon/core: disallow probe_hits overflow on attrs only monitoring
Date: Fri, 10 Jul 2026 06:46:38 -0700

When any damon_probe->weight is set, DAMON will do only probe monitoring. 
probe_hits is 'unsigned char'.  It could overflow when the aggregation
interval is larger than the sampling interval times 256. 
damon_as_probe_weights() always return false, so such overflow cannot
happen.  Even if it happens, it only degrades the monitoring results.

That said, the overflow is not intentional.  It is better to be prevented
as long as the cost is not expensive.  Disallow the overflow by adding a
validation logic on the core layer parameters validation function.

Link: https://lore.kernel.org/[email protected]
Signed-off-by: SJ Park <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

 mm/damon/core.c |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)

--- a/mm/damon/core.c~mm-damon-core-disallow-probe_hits-overflow-on-attrs-only-monitoring
+++ a/mm/damon/core.c
@@ -1332,6 +1332,19 @@ static void damos_set_filters_default_re
 		damos_filters_default_reject(&s->ops_filters);
 }
 
+static bool damon_valid_probe_params(struct damon_ctx *ctx)
+{
+	unsigned long sample_interval;
+
+	if (!damon_has_probe_weights(ctx))
+		return true;
+
+	sample_interval = ctx->attrs.sample_interval ? : 1;
+	if (ctx->attrs.aggr_interval / sample_interval > U8_MAX)
+		return false;
+	return true;
+}
+
 /*
  * damos_commit_dests() - Copy migration destinations from @src to @dst.
  * @dst:	Destination structure to update.
@@ -1736,6 +1749,9 @@ static int __damon_commit_ctx(struct dam
 		}
 	}
 
+	if (!damon_valid_probe_params(src))
+		return -EINVAL;
+
 	err = damon_commit_schemes(dst, src);
 	if (err)
 		return err;
_

Patches currently in -mm which might be from [email protected] are

mm-damon-adjust-isolated-pages-stat-for-damos_migrate_hotcold.patch
samples-damon-mtier-error-out-for-zero-quota-goal-target-values.patch
mm-damon-lru_sort-error-out-for-10000-active_mem_bp.patch
mm-damon-reclaim-skip-damon_call-if-ctx-has-not-started.patch
mm-damon-lru_sort-skip-damon_call-if-ctx-has-not-started.patch
mm-damon-core-skip-aging-from-repeated-aggressive-merging.patch
mm-damon-core-hide-private-damon_region-fields.patch
mm-damon-core-hide-private-damon_target-fields.patch
mm-damon-core-hide-private-damos_quota_goal-fields.patch
mm-damon-core-hide-private-damos_quota-fields.patch
mm-damon-core-hide-private-damos_filter-fields.patch
mm-damon-core-hide-private-damos-fields.patch
mm-damon-core-hide-private-damon_filter-fields.patch
mm-damon-core-hide-private-damon_probe-fields.patch
mm-damon-sysfs-do-not-directly-access-damon_ctx-ops.patch
mm-damon-core-hide-core-private-damon_ctx-fields.patch
mm-damon-core-avoid-infinite-kdamond_merge_regions-internal-loop.patch
mm-damon-tests-core-kunit-catch-test-failure-in-test_merge_regions_of.patch
mm-damon-vaddr-drop-last-same-folio-access-check-optimization.patch
mm-damon-paddr-drop-last-same-folio-access-check-reuse-optimization.patch
mm-damon-sysfs-read-addr_unit-only-once-in-damon_sysfs_apply_inputs.patch
mm-damon-sysfs-read-ops_id-only-once-in-damon_sysfs_apply_inputs.patch
mm-damon-core-initialize-damos-last_applied.patch
mm-damon-core-kunit-check-region-count-before-testing-in-split_at.patch
mm-damon-vaddr-kunit-check-region-count-in-three_regions-test.patch
mm-damon-core-kunit-handle-region-split-failure-in-filter_out.patch
mm-damon-core-kunit-skip-wrong-dest-walk-in-commit_dests_for.patch
mm-damon-core-kunit-skip-wrong-quota-goal-walk-in-commit_quota_goals.patch
mm-damon-core-kunit-skip-wrong-region-walk-in-commit_target_regions.patch
mm-damon-ops-common-use-nr_accesses-moving-sum-for-quota-score.patch
mm-damon-core-handle-region-split-failure-in-apply_min_nr_regions.patch