On Mon, Jun 8, 2020 at 1:26 PM Alexander Gordeev <agordeev@xxxxxxxxxxxxx> wrote:
>
> Commit 2d6261583be0 ("lib: rework bitmap_parse()") does not
> take into account order of halfwords on 64-bit big endian
> architectures. As result (at least) Receive Packet Steering,
> IRQ affinity masks and runtime kernel test "test_bitmap" get
> broken on s390.
...
> +#if defined(__BIG_ENDIAN) && defined(CONFIG_64BIT)
I think it's better to re-use existing patterns.
ipc/sem.c:1682:#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN)
> +static void save_x32_chunk(unsigned long *maskp, u32 chunk, int chunk_idx)
> +{
> + maskp += (chunk_idx / 2);
> + ((u32 *)maskp)[(chunk_idx & 1) ^ 1] = chunk;
> +}
> +#else
> +static void save_x32_chunk(unsigned long *maskp, u32 chunk, int chunk_idx)
> +{
> + ((u32 *)maskp)[chunk_idx] = chunk;
> +}
> +#endif
See below.
...
> - end = bitmap_get_x32_reverse(start, end, bitmap++);
> + end = bitmap_get_x32_reverse(start, end, &chunk);
> if (IS_ERR(end))
> return PTR_ERR(end);
> +
> + save_x32_chunk(maskp, chunk, chunk_idx++);
Can't we simple do
int chunk_index = 0;
...
do {
#if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN)
end = bitmap_get_x32_reverse(start, end,
bitmap[chunk_index ^ 1]);
#else
end = bitmap_get_x32_reverse(start, end, bitmap[chunk_index]);
#endif
...
} while (++chunk_index);
?
--
With Best Regards,
Andy Shevchenko
