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author | John Fastabend <john.fastabend@gmail.com> | 2014-09-19 21:50:34 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2014-09-22 15:59:21 -0400 |
commit | de5df63228fcfbd5bb7fd883774c18fec9e61f12 (patch) | |
tree | 4eb60e8f52cdedc39237888272e5ed39a914512e /lib | |
parent | a1ddcfee2d9ae172d0095f3f8227f7fa53288c65 (diff) | |
download | op-kernel-dev-de5df63228fcfbd5bb7fd883774c18fec9e61f12.zip op-kernel-dev-de5df63228fcfbd5bb7fd883774c18fec9e61f12.tar.gz |
net: sched: cls_u32 changes to knode must appear atomic to readers
Changes to the cls_u32 classifier must appear atomic to the
readers. Before this patch if a change is requested for both
the exts and ifindex, first the ifindex is updated then the
exts with tcf_exts_change(). This opens a small window where
a reader can have a exts chain with an incorrect ifindex. This
violates the the RCU semantics.
Here we resolve this by always passing u32_set_parms() a copy
of the tc_u_knode to work on and then inserting it into the hash
table after the updates have been successfully applied.
Tested with the following short script:
#tc filter add dev p3p2 parent 8001:0 protocol ip prio 99 handle 1: \
u32 divisor 256
#tc filter add dev p3p2 parent 8001:0 protocol ip prio 99 \
u32 link 1: hashkey mask ffffff00 at 12 \
match ip src 192.168.8.0/2
#tc filter add dev p3p2 parent 8001:0 protocol ip prio 102 \
handle 1::10 u32 classid 1:2 ht 1: \
match ip src 192.168.8.0/8 match ip tos 0x0a 1e
#tc filter change dev p3p2 parent 8001:0 protocol ip prio 102 \
handle 1::10 u32 classid 1:2 ht 1: \
match ip src 1.1.0.0/8 match ip tos 0x0b 1e
CC: Eric Dumazet <edumazet@google.com>
CC: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'lib')
0 files changed, 0 insertions, 0 deletions