+ mm-damon-core-support-addr_unit-on-damon_find_biggest_system_ram-fix.patch added to mm-unstable branch

+ mm-damon-core-support-addr_unit-on-damon_find_biggest_system_ram-fix.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/damon/core: verify found biggest system ram
has been added to the -mm mm-unstable branch.  Its filename is
     mm-damon-core-support-addr_unit-on-damon_find_biggest_system_ram-fix.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-core-support-addr_unit-on-damon_find_biggest_system_ram-fix.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: SeongJae Park <sj@kernel.org>
Subject: mm/damon/core: verify found biggest system ram
Date: Mon, 16 Mar 2026 23:32:48 -0700

On 32 bit systems having PAE (>4 GiB physical memory address sapce), the
final start and end address could overflow, resulting in returning an
invalid address range.  Verify the returning region.  Also remove the
resource validation after walk_system_ram_res(), since the validation
means not a lot.

Link: https://lkml.kernel.org/r/20260317144725.88524-1-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Yang yingliang <yangyingliang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/damon/core.c |    5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

--- a/mm/damon/core.c~mm-damon-core-support-addr_unit-on-damon_find_biggest_system_ram-fix
+++ a/mm/damon/core.c
@@ -3089,11 +3089,10 @@ static bool damon_find_biggest_system_ra
 	struct resource res = {};
 
 	walk_system_ram_res(0, -1, &res, walk_system_ram);
-	if (res.end < res.start)
-		return false;
-
 	*start = damon_res_to_core_addr(res.start, addr_unit);
 	*end = damon_res_to_core_addr(res.end + 1, addr_unit);
+	if (*end <= *start)
+		return false;
 	return true;
 }
 
_

Patches currently in -mm which might be from sj@kernel.org are

mm-damon-stat-monitor-all-system-ram-resources.patch
mm-damon-core-set-quota-score-histogram-with-core-filters.patch
mm-damon-core-do-non-safe-region-walk-on-kdamond_apply_schemes.patch
mm-damon-core-split-regions-for-min_nr_regions.patch
mm-damon-vaddr-do-not-split-regions-for-min_nr_regions.patch
mm-damon-test-core-kunit-add-damon_apply_min_nr_regions-test.patch
mm-damon-add-config_damon_debug_sanity.patch
mm-damon-core-add-damon_new_region-debug_sanity-check.patch
mm-damon-core-add-damon_del_region-debug_sanity-check.patch
mm-damon-core-add-damon_nr_regions-debug_sanity-check.patch
mm-damon-core-add-damon_merge_two_regions-debug_sanity-check.patch
mm-damon-core-add-damon_merge_regions_of-debug_sanity-check.patch
mm-damon-core-add-damon_split_region_at-debug_sanity-check.patch
mm-damon-core-add-damon_reset_aggregated-debug_sanity-check.patch
mm-damon-tests-kunitconifg-enable-damon_debug_sanity.patch
selftests-damon-config-enable-damon_debug_sanity.patch
mm-damon-tests-core-kunit-add-a-test-for-damon_commit_ctx.patch
docs-mm-damon-design-document-the-power-of-two-limitation-for-addr_unit.patch
mm-damon-core-remove-damos_set_next_apply_sis-duplicates.patch
mm-damon-core-use-time_before-for-next_apply_sis.patch
mm-damon-core-use-time_after_eq-in-kdamond_fn.patch
mm-damon-core-use-mult_frac.patch
mm-damon-tests-core-kunit-add-a-test-for-damon_is_last_region.patch
mm-damon-core-clarify-damon_set_attrs-usages.patch
mm-damon-document-non-zero-length-damon_region-assumption.patch
docs-admin-guide-mm-damn-lru_sort-fix-intervals-autotune-parameter-name.patch
docs-mm-damon-maintainer-profile-use-flexible-review-cadence.patch
docs-mm-damon-index-fix-typo-autoamted-automated.patch
mm-damon-core-introduce-damos_quota_goal_tuner.patch
mm-damon-core-allow-quota-goals-set-zero-effective-size-quota.patch
mm-damon-core-introduce-damos_quota_goal_tuner_temporal.patch
mm-damon-sysfs-schemes-implement-quotas-goal_tuner-file.patch
docs-mm-damon-design-document-the-goal-based-quota-tuner-selections.patch
docs-admin-guide-mm-damon-usage-document-goal_tuner-sysfs-file.patch
docs-abi-damon-update-for-goal_tuner.patch
mm-damon-tests-core-kunit-test-goal_tuner-commit.patch
selftests-damon-_damon_sysfs-support-goal_tuner-setup.patch
selftests-damon-drgn_dump_damon_status-support-quota-goal_tuner-dumping.patch
selftests-damon-sysfspy-test-goal_tuner-commit.patch
mm-damon-core-fix-wrong-end-address-assignment-on-walk_system_ram.patch
mm-damon-core-support-addr_unit-on-damon_find_biggest_system_ram.patch
mm-damon-core-support-addr_unit-on-damon_find_biggest_system_ram-fix.patch
mm-damon-core-receive-addr_unit-on-damon_set_region_biggest_system_ram_default.patch
mm-damon-core-receive-addr_unit-on-damon_set_region_biggest_system_ram_default-fix.patch
mm-damon-reclaim-respect-addr_unit-on-default-monitoring-region-setup.patch
mm-damon-lru_sort-respect-addr_unit-on-default-monitoring-region-setup.patch