This is a note to let you know that I've just added the patch titled

bonding: refine bond_fold_stats() wrap detection

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: bonding-refine-bond_fold_stats-wrap-detection.patch and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Sun Mar 18 16:55:33 CET 2018

From: Eric Dumazet edumazet@google.com Date: Wed, 29 Mar 2017 10:45:44 -0700 Subject: bonding: refine bond_fold_stats() wrap detection

From: Eric Dumazet edumazet@google.com

[ Upstream commit 142c6594acbcc32391af9c15f8cd65c6c177698f ]

Some device drivers reset their stats at down/up events, possibly fooling bonding stats, since they operate with relative deltas.

It is nearly not possible to fix drivers, since some of them compute the tx/rx counters based on per rx/tx queue stats, and the queues can be reconfigured (ethtool -L) between the down/up sequence.

Lets avoid accumulating 'negative' values that render bonding stats useless.

It is better to lose small deltas, assuming the bonding stats are fetched at a reasonable frequency.

Fixes: 5f0c5f73e5ef ("bonding: make global bonding stats more reliable") Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/bonding/bond_main.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)

--- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -3331,12 +3331,17 @@ static void bond_fold_stats(struct rtnl_ for (i = 0; i < sizeof(*_res) / sizeof(u64); i++) { u64 nv = new[i]; u64 ov = old[i]; + s64 delta = nv - ov;

/* detects if this particular field is 32bit only */ if (((nv | ov) >> 32) == 0) - res[i] += (u32)nv - (u32)ov; - else - res[i] += nv - ov; + delta = (s64)(s32)((u32)nv - (u32)ov); + + /* filter anomalies, some drivers reset their stats + * at down/up events. + */ + if (delta > 0) + res[i] += delta; } }

Patches currently in stable-queue which might be from edumazet@google.com are

queue-4.9/selinux-check-for-address-length-in-selinux_socket_bind.patch queue-4.9/bonding-refine-bond_fold_stats-wrap-detection.patch