diff options
| author | SeongJae Park <sj@kernel.org> | 2026-03-06 18:29:08 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-04-05 23:53:20 +0300 |
| commit | 0bb7682fdb533be8412e5678eab246144d855138 (patch) | |
| tree | 6a8a2f052882fe39d033596b67a91dc60d9e9a51 | |
| parent | 242a764abe149f297273be18fdb66cfeaf27dec2 (diff) | |
| download | linux-0bb7682fdb533be8412e5678eab246144d855138.tar.xz | |
mm/damon/core: add damon_merge_two_regions() debug_sanity check
A data corruption could cause damon_merge_two_regions() creating zero
length DAMON regions. Add a sanity check for that under
CONFIG_DAMON_DEBUG_SANITY.
Link: https://lkml.kernel.org/r/20260306152914.86303-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | mm/damon/core.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/mm/damon/core.c b/mm/damon/core.c index 16bedde920f0..0fa694aff617 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -2475,6 +2475,21 @@ static void kdamond_apply_schemes(struct damon_ctx *c) mutex_unlock(&c->walk_control_lock); } +#ifdef CONFIG_DAMON_DEBUG_SANITY +static void damon_verify_merge_two_regions( + struct damon_region *l, struct damon_region *r) +{ + /* damon_merge_two_regions() may created incorrect left region */ + WARN_ONCE(l->ar.start >= l->ar.end, "l: %lu-%lu, r: %lu-%lu\n", + l->ar.start, l->ar.end, r->ar.start, r->ar.end); +} +#else +static void damon_verify_merge_two_regions( + struct damon_region *l, struct damon_region *r) +{ +} +#endif + /* * Merge two adjacent regions into one region */ @@ -2488,6 +2503,7 @@ static void damon_merge_two_regions(struct damon_target *t, l->nr_accesses_bp = l->nr_accesses * 10000; l->age = (l->age * sz_l + r->age * sz_r) / (sz_l + sz_r); l->ar.end = r->ar.end; + damon_verify_merge_two_regions(l, r); damon_destroy_region(r, t); } |