On Tue, 2016-09-27 at 03:42 -0400, Vishwanath Pai wrote:
> Fix link error in 32bit arch because of 64bit division
>
> Division of 64bit integers will cause linker error undefined reference
> to `__udivdi3'. Fix this by replacing divisions with div64_64
>
> Signed-off-by: Vishwanath Pai <[email protected]>
>
> ---
> net/netfilter/xt_hashlimit.c | 15 ++++++++-------
> 1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
> index 44a095e..7fc694e 100644
> --- a/net/netfilter/xt_hashlimit.c
> +++ b/net/netfilter/xt_hashlimit.c
> @@ -465,19 +465,20 @@ static u64 user2credits(u64 user, int revision)
> {
> if (revision == 1) {
> /* If multiplying would overflow... */
> - if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY_v1))
> + if (user > div64_u64(0xFFFFFFFF, (HZ*CREDITS_PER_JIFFY_v1)))
How can this be needed ? 0xFFFFFFFF is 32bits, compiler knows how to
compute 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY_v1) itself, without using a
64 bit divide !
Please be selective.
> /* Divide first. */
> - return (user / XT_HASHLIMIT_SCALE) *\
> + return div64_u64(user, XT_HASHLIMIT_SCALE) *\
> HZ * CREDITS_PER_JIFFY_v1;
>
> - return (user * HZ * CREDITS_PER_JIFFY_v1) \
> - / XT_HASHLIMIT_SCALE;
> + return div64_u64((user * HZ * CREDITS_PER_JIFFY_v1),
> + XT_HASHLIMIT_SCALE);
> } else {
> - if (user > 0xFFFFFFFFFFFFFFFF / (HZ*CREDITS_PER_JIFFY))
> - return (user / XT_HASHLIMIT_SCALE_v2) *\
Probably same remark here.
> + if (user > div64_u64(0xFFFFFFFFFFFFFFFF,
> (HZ*CREDITS_PER_JIFFY)))
> + return div64_u64(user, XT_HASHLIMIT_SCALE_v2) *\
> HZ * CREDITS_PER_JIFFY;
>
> - return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE_v2;
> + return div64_u64((user * HZ * CREDITS_PER_JIFFY),
> + XT_HASHLIMIT_SCALE_v2);
> }
> }
>
