On Thu, Jul 09, 2026 at 01:40:06PM +0200, Christophe Leroy (CS GROUP) wrote:
> Erhard reports failure of bitmap tests on powerpc:
>
> test_bitmap: loaded.
> test_bitmap: [lib/test_bitmap.c:397] bitmaps contents differ: expected
> "1,3-4,9", got "1,3-4,9,65-71,73-79,81-87,89-95,97-99"
> test_bitmap: parselist('0-2047:128/256'): 912
> test_bitmap: scnprintf("%*pbl", '0-32767'): 5977
> test_bitmap: test_bitmap_read_perf: 1191082
> test_bitmap: test_bitmap_write_perf: 1270153
> test_bitmap: failed 1 out of 208655 tests
>
> The happens mainly when CONFIG_INIT_STACK_ALL_PATTERN is set.
>
> Commit 6b5a4b687367 ("bitmap: Add test for out-of-boundary
> modifications for scatter & gather") extended the test to
> out-of-boundary bits, but those bits where left uninitialised.
>
> Properly initialise the entire result bitmap before the test.
>
> Reported-by: Erhard Furtner <[email protected]>
> Closes:
> https://lore.kernel.org/all/[email protected]
> Fixes: 6b5a4b687367 ("bitmap: Add test for out-of-boundary modifications for
> scatter & gather")
> Signed-off-by: Christophe Leroy (CS GROUP) <[email protected]>
Applied, thanks!
> ---
> lib/test_bitmap.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
> index 69813c10e6c0..448c3eb48a4a 100644
> --- a/lib/test_bitmap.c
> +++ b/lib/test_bitmap.c
> @@ -392,6 +392,7 @@ static void __init test_bitmap_sg(void)
>
> /* Scatter/gather relationship */
> bitmap_zero(bmap_tmp, 100);
> + bitmap_zero(bmap_res, 100);
> bitmap_gather(bmap_tmp, bmap_scatter, sg_mask, nbits);
> bitmap_scatter(bmap_res, bmap_tmp, sg_mask, nbits);
> expect_eq_bitmap(bmap_scatter, bmap_res, 100);
> --
> 2.54.0
