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author | Jarod Wilson <jarod@redhat.com> | 2016-02-01 18:51:04 -0500 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-02-06 02:59:50 -0500 |
commit | 9256645af09807bc52fa8b2e66ecd28ab25318c4 (patch) | |
tree | 8b677e50b06f7f5261681967b51db738cb57438e /net/core/dev.c | |
parent | 817298102b0bc936b08dfcc5fbcc2213157050f2 (diff) | |
download | op-kernel-dev-9256645af09807bc52fa8b2e66ecd28ab25318c4.zip op-kernel-dev-9256645af09807bc52fa8b2e66ecd28ab25318c4.tar.gz |
net/core: relax BUILD_BUG_ON in netdev_stats_to_stats64
The netdev_stats_to_stats64 function copies the deprecated
net_device_stats format stats into rtnl_link_stats64 for legacy support
purposes, but with the BUILD_BUG_ON as it was, it wasn't possible to
extend rtnl_link_stats64 without also extending net_device_stats. Relax
the BUILD_BUG_ON to only require that rtnl_link_stats64 is larger, and
zero out all the stat counters that aren't present in net_device_stats.
CC: Eric Dumazet <edumazet@google.com>
CC: netdev@vger.kernel.org
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/dev.c')
-rw-r--r-- | net/core/dev.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 8cba3d8..65863e5 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -7253,24 +7253,31 @@ void netdev_run_todo(void) } } -/* Convert net_device_stats to rtnl_link_stats64. They have the same - * fields in the same order, with only the type differing. +/* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has + * all the same fields in the same order as net_device_stats, with only + * the type differing, but rtnl_link_stats64 may have additional fields + * at the end for newer counters. */ void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64, const struct net_device_stats *netdev_stats) { #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)); + /* zero out counters that only exist in rtnl_link_stats64 */ + memset((char *)stats64 + sizeof(*netdev_stats), 0, + sizeof(*stats64) - sizeof(*netdev_stats)); #else - size_t i, n = sizeof(*stats64) / sizeof(u64); + size_t i, n = sizeof(*netdev_stats) / sizeof(unsigned long); const unsigned long *src = (const unsigned long *)netdev_stats; u64 *dst = (u64 *)stats64; - BUILD_BUG_ON(sizeof(*netdev_stats) / sizeof(unsigned long) != - sizeof(*stats64) / sizeof(u64)); + BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64)); for (i = 0; i < n; i++) dst[i] = src[i]; + /* zero out counters that only exist in rtnl_link_stats64 */ + memset((char *)stats64 + n * sizeof(u64), 0, + sizeof(*stats64) - n * sizeof(u64)); #endif } EXPORT_SYMBOL(netdev_stats_to_stats64); |