Re: [PATCH v3 1/6] binder: Fix selftest page indexing
From: Kees Cook
Date: Wed Jul 16 2025 - 10:27:34 EST
On Mon, Jul 14, 2025 at 11:53:14AM -0700, Tiffany Yang wrote:
> The binder allocator selftest was only checking the last page of buffers
> that ended on a page boundary. Correct the page indexing to account for
> buffers that are not page-aligned.
>
> Signed-off-by: Tiffany Yang <ynaffit@xxxxxxxxxx>
> ---
> drivers/android/binder_alloc_selftest.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/android/binder_alloc_selftest.c b/drivers/android/binder_alloc_selftest.c
> index c88735c54848..486af3ec3c02 100644
> --- a/drivers/android/binder_alloc_selftest.c
> +++ b/drivers/android/binder_alloc_selftest.c
> @@ -142,12 +142,12 @@ static void binder_selftest_free_buf(struct binder_alloc *alloc,
> for (i = 0; i < BUFFER_NUM; i++)
> binder_alloc_free_buf(alloc, buffers[seq[i]]);
>
> - for (i = 0; i < end / PAGE_SIZE; i++) {
> /**
> * Error message on a free page can be false positive
> * if binder shrinker ran during binder_alloc_free_buf
> * calls above.
> */
> + for (i = 0; i <= (end - 1) / PAGE_SIZE; i++) {
Nit: this comment is now not aligned correctly. Probably the best would
be the leave the "for" line above the comment.
-Kees
> if (list_empty(page_to_lru(alloc->pages[i]))) {
> pr_err_size_seq(sizes, seq);
> pr_err("expect lru but is %s at page index %d\n",
> --
> 2.50.0.727.gbf7dc18ff4-goog
>
--
Kees Cook