[PATCH 1/1] mm: kfence: skip kmemleak alloc in kfence_pool

From: yee.lee
Date: Thu Jun 23 2022 - 07:20:11 EST


From: Yee Lee <yee.lee@xxxxxxxxxxxx>

Use MEMBLOCK_ALLOC_NOLEAKTRACE to skip kmemleak registration when
the kfence pool is allocated from memblock. And the kmemleak_free
later can be removed too.

Signed-off-by: Yee Lee <yee.lee@xxxxxxxxxxxx>

---
mm/kfence/core.c | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index 4e7cd4c8e687..0d33d83f5244 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -600,14 +600,6 @@ static unsigned long kfence_init_pool(void)
addr += 2 * PAGE_SIZE;
}

- /*
- * The pool is live and will never be deallocated from this point on.
- * Remove the pool object from the kmemleak object tree, as it would
- * otherwise overlap with allocations returned by kfence_alloc(), which
- * are registered with kmemleak through the slab post-alloc hook.
- */
- kmemleak_free(__kfence_pool);
-
return 0;
}

@@ -831,8 +823,14 @@ void __init kfence_alloc_pool(void)
{
if (!kfence_sample_interval)
return;
-
- __kfence_pool = memblock_alloc(KFENCE_POOL_SIZE, PAGE_SIZE);
+ /*
+ * The pool is live and will never be deallocated from this point on.
+ * Skip the pool object from the kmemleak object allocation, as it would
+ * otherwise overlap with allocations returned by kfence_alloc(), which
+ * are registered with kmemleak through the slab post-alloc hook.
+ */
+ __kfence_pool = memblock_alloc_try_nid(KFENCE_POOL_SIZE, PAGE_SIZE,
+ MEMBLOCK_LOW_LIMIT, MEMBLOCK_ALLOC_NOLEAKTRACE, NUMA_NO_NODE);

if (!__kfence_pool)
pr_err("failed to allocate pool\n");
--
2.18.0