Eric Dumazet 0d32ef8cef net: sched: fix panic in rate estimators ... Doing the following commands on a non idle network device panics the box instantly, because cpu_bstats gets overwritten by stats. tc qdisc add dev eth0 root <your_favorite_qdisc> ... some traffic (one packet is enough) ... tc qdisc replace dev eth0 root est 1sec 4sec <your_favorite_qdisc> [ 325.355596] BUG: unable to handle kernel paging request at ffff8841dc5a074c [ 325.362609] IP: [<ffffffff81541c9e>] __gnet_stats_copy_basic+0x3e/0x90 [ 325.369158] PGD 1fa7067 PUD 0 [ 325.372254] Oops: 0000 [#1] SMP [ 325.375514] Modules linked in: ... [ 325.398346] CPU: 13 PID: 14313 Comm: tc Not tainted 3.19.0-smp-DEV #1163 [ 325.412042] task: ffff8800793ab5d0 ti: ffff881ff2fa4000 task.ti: ffff881ff2fa4000 [ 325.419518] RIP: 0010:[<ffffffff81541c9e>] [<ffffffff81541c9e>] __gnet_stats_copy_basic+0x3e/0x90 [ 325.428506] RSP: 0018:ffff881ff2fa7928 EFLAGS: 00010286 [ 325.433824] RAX: 000000000000000c RBX: ffff881ff2fa796c RCX: 000000000000000c [ 325.440988] RDX: ffff8841dc5a0744 RSI: 0000000000000060 RDI: 0000000000000060 [ 325.448120] RBP: ffff881ff2fa7948 R08: ffffffff81cd4f80 R09: 0000000000000000 [ 325.455268] R10: ffff883ff223e400 R11: 0000000000000000 R12: 000000015cba0744 [ 325.462405] R13: ffffffff81cd4f80 R14: ffff883ff223e460 R15: ffff883feea0722c [ 325.469536] FS: 00007f2ee30fa700(0000) GS:ffff88407fa20000(0000) knlGS:0000000000000000 [ 325.477630] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 325.483380] CR2: ffff8841dc5a074c CR3: 0000003feeae9000 CR4: 00000000001407e0 [ 325.490510] Stack: [ 325.492524] ffff883feea0722c ffff883fef719dc0 ffff883feea0722c ffff883ff223e4a0 [ 325.499990] ffff881ff2fa79a8 ffffffff815424ee ffff883ff223e49c 000000015cba0744 [ 325.507460] 00000000f2fa7978 0000000000000000 ffff881ff2fa79a8 ffff883ff223e4a0 [ 325.514956] Call Trace: [ 325.517412] [<ffffffff815424ee>] gen_new_estimator+0x8e/0x230 [ 325.523250] [<ffffffff815427aa>] gen_replace_estimator+0x4a/0x60 [ 325.529349] [<ffffffff815718ab>] tc_modify_qdisc+0x52b/0x590 [ 325.535117] [<ffffffff8155edd0>] rtnetlink_rcv_msg+0xa0/0x240 [ 325.540963] [<ffffffff8155ed30>] ? __rtnl_unlock+0x20/0x20 [ 325.546532] [<ffffffff8157f811>] netlink_rcv_skb+0xb1/0xc0 [ 325.552145] [<ffffffff8155b355>] rtnetlink_rcv+0x25/0x40 [ 325.557558] [<ffffffff8157f0d8>] netlink_unicast+0x168/0x220 [ 325.563317] [<ffffffff8157f47c>] netlink_sendmsg+0x2ec/0x3e0 Lets play safe and not use an union : percpu 'pointers' are mostly read anyway, and we have typically few qdiscs per host. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: John Fastabend <john.fastabend@gmail.com> Fixes: 22e0f8b932 ("net: sched: make bstats per cpu and estimator RCU safe") Signed-off-by: David S. Miller <davem@davemloft.net>		2015-01-31 17:49:37 -08:00
..
acpi	ACPI / processor: Convert apic_id to phys_id to make it arch agnostic	2015-01-05 23:32:42 +01:00
asm-generic	mm: mmu_gather: use tlb->end != 0 only for TLB invalidation	2015-01-13 15:20:40 +13:00
clocksource
crypto	crypto: af_alg - add user space interface for AEAD	2014-12-05 23:56:55 +08:00
drm	Revert "drm/gem: Warn on illegal use of the dumb buffer interface v2"	2014-12-24 13:13:22 +10:00
dt-bindings	ARM: dt: GIC: Spelling s/specific/specifier/, s/flaggs/flags/	2015-01-13 13:48:16 -06:00
keys
kvm	arm/arm64: KVM: Require in-kernel vgic for the arch timers	2014-12-15 11:50:42 +01:00
linux	net: Fix vlan_get_protocol for stacked vlan	2015-01-30 18:03:47 -08:00
math-emu
media	[media] media: v4l2-image-sizes.h: correct the SVGA height definition	2014-12-04 13:56:56 -02:00
memory
misc
net	net: sched: fix panic in rate estimators	2015-01-31 17:49:37 -08:00
pcmcia
ras
rdma	IB/core: Implement support for MMU notifiers regarding on demand paging regions	2014-12-15 18:13:36 -08:00
rxrpc
scsi	SCSI for-linus on 20141220	2014-12-20 13:42:57 -08:00
soc	Merge branch 'at91/cleanup5' into next/drivers	2014-12-08 18:29:20 +01:00
sound	ALSA: pcm: Fix kerneldoc for params_*() functions	2014-12-30 16:41:11 +01:00
target	target: Drop left-over fabric_max_sectors attribute	2015-01-09 15:22:05 -08:00
trace	KVM: fix sparse warning in include/trace/events/kvm.h	2015-01-19 11:07:57 +01:00
uapi	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2015-01-20 18:19:31 +12:00
video	OMAPDSS: Remove all references to obsolete HDMI audio callbacks	2014-12-01 11:09:59 +02:00
xen	x86/xen: properly retrieve NMI reason	2015-01-13 09:39:50 +00:00
Kbuild