On Tue, 28 Jun 2022 at 13:37, yee.lee via kasan-dev
<kasan-dev@xxxxxxxxxxxxxxxx> wrote:
>
> From: Yee Lee <yee.lee@xxxxxxxxxxxx>
>
> This patch solves two issues.
>
> (1) The pool allocated by memblock needs to unregister from
> kmemleak scanning. Apply kmemleak_ignore_phys to replace the
> original kmemleak_free as its address now is stored in the phys tree.
>
> (2) The pool late allocated by page-alloc doesn't need to unregister.
> Move out the freeing operation from its call path.
>
> Suggested-by: Catalin Marinas <catalin.marinas@xxxxxxx>
> Suggested-by: Marco Elver <elver@xxxxxxxxxx>
> Signed-off-by: Yee Lee <yee.lee@xxxxxxxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Does this want a Fixes tag?
> ---
> mm/kfence/core.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/mm/kfence/core.c b/mm/kfence/core.c
> index 4e7cd4c8e687..32a4a75e820c 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;
> }
>
> @@ -620,8 +612,16 @@ static bool __init kfence_init_pool_early(void)
>
> addr = kfence_init_pool();
>
> - if (!addr)
> + if (!addr) {
> + /*
> + * The pool is live and will never be deallocated from this point on.
> + * Ignore the pool object from the kmemleak phys 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_ignore_phys(__pa(__kfence_pool));
> return true;
> + }
>
> /*
> * Only release unprotected pages, and do not try to go back and change
> --
> 2.18.0
