[NETFILTER]: Fix div64_64 in ipt_connbytes

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/netfilter/ipt_connbytes.c b/net/ipv4/netfilter/ipt_connbytes.c
index 0dfb52c0e808000d51b588a014c6657043c666be..47128c073d8538e3c61191f39f2daffbf9f56c5b 100644 (file)
--- a/net/ipv4/netfilter/ipt_connbytes.c
+++ b/net/ipv4/netfilter/ipt_connbytes.c
@@ -22,23 +22,19 @@ MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
 MODULE_DESCRIPTION("iptables match for matching number of pkts/bytes per connection");
 
 /* 64bit divisor, dividend and result. dynamic precision */
-static u_int64_t div64_64(u_int64_t divisor, u_int64_t dividend)
+static u_int64_t div64_64(u_int64_t dividend, u_int64_t divisor)
 {
-       u_int64_t result = divisor;
-
-       if (dividend > 0xffffffff) {
-               int first_bit = find_first_bit((unsigned long *) &dividend, sizeof(dividend));
-               /* calculate number of bits to shift. shift exactly enough
-                * bits to make dividend fit in 32bits. */
-               int num_shift = (64 - 32 - first_bit);
-               /* first bit has to be < 32, since dividend was > 0xffffffff */
-               result = result >> num_shift;
-               dividend = dividend >> num_shift;
-       }
+       u_int32_t d = divisor;
+
+       if (divisor > 0xffffffffULL) {
+               unsigned int shift = fls(divisor >> 32);
 
-       do_div(divisor, dividend);
+               d = divisor >> shift;
+               dividend >>= shift;
+       }
 
-       return divisor;
+       do_div(dividend, d);
+       return dividend;
 }
 
 static int