On Thu, Jan 28, 2016 at 05:00:02AM -0800, Eric Dumazet wrote:
> On Thu, 2016-01-28 at 01:18 -0500, Jarod Wilson wrote:
>
> > Or not. Now I remember why I added that in the first place:
> >
> > In file included from ./arch/x86/include/asm/uaccess.h:7:0,
> > from net/core/dev.c:75:
> > net/core/dev.c: In function 'netdev_stats_to_stats64':
> > include/linux/compiler.h:484:20: error: call to '__compiletime_assert_7263'
> > declared with attribute error: BUILD_BUG_ON failed: sizeof(*stats64) !=
> > sizeof(*netdev_stats)
> > prefix ## suffix(); \
> > ^
> >
> > Things are actually hard-wired to require that addition at the moment, or
> > you get the above build failure. Not sure if it's safe to remove that
> > BUILD_BUG_ON() yet, haven't looked closely, it's past my bed time. :)
> >
>
> This was done for the transition from "unsigned long" to "u64", which is
> a nop on 64bit arches.
>
> But as we do not need to be compatible, since no linux kernel in the
> past had this new field in struct net_device_stats,
>
> and we do not need to add this new field as it is only accessed from
> core networking stack [1], you need to adapt this helper.
Something like this then:
diff --git a/net/core/dev.c b/net/core/dev.c
index 82334c6..2ca3eab 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -7262,15 +7262,16 @@ void netdev_run_todo(void)
void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
const struct net_device_stats *netdev_stats)
{
+ memset(stats64, 0, sizeof(*stats64));
#if BITS_PER_LONG == 64
- BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats));
+ BUILD_BUG_ON(sizeof(*stats64) < sizeof(*netdev_stats));
memcpy(stats64, netdev_stats, sizeof(*stats64));
#else
size_t i, n = sizeof(*stats64) / sizeof(u64);
const unsigned long *src = (const unsigned long *)netdev_stats;
u64 *dst = (u64 *)stats64;
- BUILD_BUG_ON(sizeof(*netdev_stats) / sizeof(unsigned long) !=
+ BUILD_BUG_ON(sizeof(*netdev_stats) / sizeof(unsigned long) >
sizeof(*stats64) / sizeof(u64));
for (i = 0; i < n; i++)
dst[i] = src[i];
Compiles locally w/o that net_device_stats addition, seems sane to me.
--
Jarod Wilson
ja...@redhat.com
