On 09/06/2017 03:57 PM, Arnd Bergmann wrote: > 64-bit division is expensive on 32-bit architectures, and > requires a special function call to avoid a link error like: > > net/netfilter/xt_hashlimit.o: In function `hashlimit_mt_common': > xt_hashlimit.c:(.text+0x1328): undefined reference to `__aeabi_uldivmod' > > In the case of hashlimit_mt_common, we don't actually need a > 64-bit operation, we can simply rewrite the function slightly > to make that clear to the compiler. > > Fixes: bea74641e378 ("netfilter: xt_hashlimit: add rate match mode") > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > --- > net/netfilter/xt_hashlimit.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c > index 10d48234f5f4..50b53d86eef5 100644 > --- a/net/netfilter/xt_hashlimit.c > +++ b/net/netfilter/xt_hashlimit.c > @@ -531,7 +531,10 @@ static u64 user2rate_bytes(u64 user) > { > u64 r; > > - r = user ? 0xFFFFFFFFULL / user : 0xFFFFFFFFULL; > + if (user > 0xFFFFFFFFULL) > + return 0; > + > + r = user ? 0xFFFFFFFFULL / (u32)user : 0xFFFFFFFFULL; > r = (r - 1) << 4; > return r; > } > I have submitted another patch to fix this: https://patchwork.ozlabs.org/patch/809881/ We have seen this problem before, I was careful not to introduce this again in the new patch but clearly I overlooked this particular line :( In the other cases we fixed it by replacing division with div64_u64(). -Vishwanath -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html