Re: [PATCH] lib/test_bitmap.c: Fix bitmap optimisation tests to report errors correctly

[Kees Cook]

On Wed, May 9, 2018 at 4:43 AM, Michael Ellerman <mpe@xxxxxxxxxxxxxx> wrote:
> From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
>
> I had neglected to increment the error counter when the tests failed,
> which made the tests noisy when they fail, but not actually return an
> error code.
>
> Reported-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
> Fixes: 3cc78125a081 ("lib/test_bitmap.c: add optimisation tests")
> Cc: stable@xxxxxxxxxxxxxxx # v4.13+
> Tested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>

FWIW:

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-Kees

> ---
>  lib/test_bitmap.c | 21 +++++++++++++++------
>  1 file changed, 15 insertions(+), 6 deletions(-)
>
> We noticed this a while back but the patch got lost.
>
> Andrew are you happy to take it?
>
> cheers
>
>
> diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
> index de16f7869fb1..6cd7d0740005 100644
> --- a/lib/test_bitmap.c
> +++ b/lib/test_bitmap.c
> @@ -331,23 +331,32 @@ static void noinline __init test_mem_optimisations(void)
>         unsigned int start, nbits;
>
>         for (start = 0; start < 1024; start += 8) {
> -               memset(bmap1, 0x5a, sizeof(bmap1));
> -               memset(bmap2, 0x5a, sizeof(bmap2));
>                 for (nbits = 0; nbits < 1024 - start; nbits += 8) {
> +                       memset(bmap1, 0x5a, sizeof(bmap1));
> +                       memset(bmap2, 0x5a, sizeof(bmap2));
> +
>                         bitmap_set(bmap1, start, nbits);
>                         __bitmap_set(bmap2, start, nbits);
> -                       if (!bitmap_equal(bmap1, bmap2, 1024))
> +                       if (!bitmap_equal(bmap1, bmap2, 1024)) {
>                                 printk("set not equal %d %d\n", start, nbits);
> -                       if (!__bitmap_equal(bmap1, bmap2, 1024))
> +                               failed_tests++;
> +                       }
> +                       if (!__bitmap_equal(bmap1, bmap2, 1024)) {
>                                 printk("set not __equal %d %d\n", start, nbits);
> +                               failed_tests++;
> +                       }
>
>                         bitmap_clear(bmap1, start, nbits);
>                         __bitmap_clear(bmap2, start, nbits);
> -                       if (!bitmap_equal(bmap1, bmap2, 1024))
> +                       if (!bitmap_equal(bmap1, bmap2, 1024)) {
>                                 printk("clear not equal %d %d\n", start, nbits);
> -                       if (!__bitmap_equal(bmap1, bmap2, 1024))
> +                               failed_tests++;
> +                       }
> +                       if (!__bitmap_equal(bmap1, bmap2, 1024)) {
>                                 printk("clear not __equal %d %d\n", start,
>                                                                         nbits);
> +                               failed_tests++;
> +                       }
>                 }
>         }
>  }
> --
> 2.14.1
>



-- 
Kees Cook
Pixel Security