linux_dsm_epyc7002/drivers/net
Martin KaFai Lau 1510d72863 net/mlx5e: Fix race in mlx5e_sw_stats and mlx5e_vport_stats
We have observed a sudden spike in rx/tx_packets and rx/tx_bytes
reported under /proc/net/dev.  There is a race in mlx5e_update_stats()
and some of the get-stats functions (the one that we hit is the
mlx5e_get_stats() which is called by ndo_get_stats64()).

In particular, the very first thing mlx5e_update_sw_counters()
does is 'memset(s, 0, sizeof(*s))'.  For example, if mlx5e_get_stats()
is unlucky at one point, rx_bytes and rx_packets could be 0.  One second
later, a normal (and much bigger than 0) value will be reported.

This patch is to use a 'struct mlx5e_sw_stats temp' to avoid
a direct memset zero on priv->stats.sw.

mlx5e_update_vport_counters() has a similar race.  Hence, addressed
together.  However, memset zero is removed instead because
it is not needed.

I am lucky enough to catch this 0-reset in rx multicast:
eth0: 41457665   76804   70    0    0    70          0     47085 15586634   87502    3    0    0     0       3          0
eth0: 41459860   76815   70    0    0    70          0     47094 15588376   87516    3    0    0     0       3          0
eth0: 41460577   76822   70    0    0    70          0         0 15589083   87521    3    0    0     0       3          0
eth0: 41463293   76838   70    0    0    70          0     47108 15595872   87538    3    0    0     0       3          0
eth0: 41463379   76839   70    0    0    70          0     47116 15596138   87539    3    0    0     0       3          0

v2: Remove memset zero from mlx5e_update_vport_counters()
v1: Use temp and memcpy

Fixes: 9218b44dcc ("net/mlx5e: Statistics handling refactoring")
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Suggested-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-24 12:15:08 -04:00
..
appletalk
arcnet lib/vsprintf.c: remove %Z support 2017-02-27 18:43:47 -08:00
bonding Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-03-04 17:31:39 -08:00
caif virtio: allow drivers to request IRQ affinity when creating VQs 2017-02-27 20:54:04 +02:00
can can: rcar_can: Do not print virtual addresses 2017-04-04 17:49:59 +02:00
cris
dsa net:dsa:mv88e6xxx: use watchdog ops for 6097 chip 2017-02-14 11:45:28 -05:00
ethernet net/mlx5e: Fix race in mlx5e_sw_stats and mlx5e_vport_stats 2017-04-24 12:15:08 -04:00
fddi
fjes fjes: Do not load fjes driver if extended socket device is not power on. 2017-03-22 12:38:17 -07:00
hamradio driver core patches for 4.11-rc1 2017-02-22 11:44:32 -08:00
hippi
hyperv netvsc: fix race during initialization 2017-03-16 21:35:33 -07:00
ieee802154 ieee802154: atusb: fix driver to work with older firmware versions 2017-01-12 22:12:43 +01:00
ipvlan ipvtap: IP-VLAN based tap driver 2017-02-11 20:59:41 -05:00
irda irda: vlsi_ir: fix check for DMA mapping errors 2017-03-25 20:14:40 -07:00
phy dp83640: don't recieve time stamps twice 2017-04-20 16:00:48 -04:00
plip
ppp sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
slip sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
team team: call netdev_change_features out of team lock 2017-04-06 13:56:49 -07:00
usb kaweth: use skb_cow_head() to deal with cloned skbs 2017-04-21 13:24:06 -04:00
vmxnet3 drivers: net: generalize napi_complete_done() 2017-01-30 15:10:42 -05:00
wan ucc/hdlc: fix two little issue 2017-03-13 21:53:48 -07:00
wimax net: wimax/i2400m: fix NULL-deref at probe 2017-03-13 12:28:40 -07:00
wireless brcmfmac: use local iftype avoiding use-after-free of virtual interface 2017-03-30 19:43:51 +03:00
xen-netback xen-netback: fix race condition on XenBus disconnect 2017-03-12 23:44:43 -07:00
dummy.c net: dummy: Introduce dummy virtual functions 2017-01-24 14:07:22 -05:00
eql.c
geneve.c geneve: lock RCU on TX path 2017-03-01 09:58:31 -08:00
gtp.c lib/vsprintf.c: remove %Z support 2017-02-27 18:43:47 -08:00
ifb.c
Kconfig vmxnet3: prevent building with 64K pages 2017-02-17 15:25:49 -05:00
LICENSE.SRC
loopback.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-02-11 02:31:11 -05:00
macsec.c macsec: fix validation failed in asynchronous operation. 2017-02-21 13:13:51 -05:00
macvlan.c tap: Abstract type of virtual interface from tap implementation 2017-02-11 20:59:41 -05:00
macvtap.c sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> 2017-03-02 08:42:32 +01:00
Makefile ipvtap: IP-VLAN based tap driver 2017-02-11 20:59:41 -05:00
mdio.c
mii.c
netconsole.c
nlmon.c
ntb_netdev.c
rionet.c
sb1000.c
Space.c
sungem_phy.c
tap.c sched/headers: Move task_struct::signal and task_struct::sighand types and accessors into <linux/sched/signal.h> 2017-03-03 01:43:37 +01:00
tun.c tun: fix inability to set offloads after disabling them via ethtool 2017-03-21 15:30:59 -07:00
veth.c
virtio_net.c virtio_net: clear MTU when out of range 2017-04-07 16:38:59 +03:00
vrf.c net: vrf: Fix setting NLM_F_EXCL flag when adding l3mdev rule 2017-04-17 13:27:54 -04:00
vxlan.c vxlan: fix ovs support 2017-03-13 16:03:42 -07:00
xen-netfront.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-02-22 10:15:09 -08:00