linux-stable.git/net/ipv6/ip6_fib.c, branch linux-3.1.y Linux kernel stable tree net: fix NULL dereferences in check_peer_redir() 2011-08-03T10:34:12+00:00 Eric Dumazet eric.dumazet@gmail.com 2011-07-29T19:00:53+00:00 f2c31e32b378a6653f8de606149d963baf11d7d3 Gergely Kalman reported crashes in check_peer_redir(). It appears commit f39925dbde778 (ipv4: Cache learned redirect information in inetpeer.) added a race, leading to possible NULL ptr dereference. Since we can now change dst neighbour, we should make sure a reader can safely use a neighbour. Add RCU protection to dst neighbour, and make sure check_peer_redir() can be called safely by different cpus in parallel. As neighbours are already freed after one RCU grace period, this patch should not add typical RCU penalty (cache cold effects) Many thanks to Gergely for providing a pretty report pointing to the bug. Reported-by: Gergely Kalman <synapse@hippy.csoma.elte.hu> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Gergely Kalman reported crashes in check_peer_redir().

It appears commit f39925dbde778 (ipv4: Cache learned redirect
information in inetpeer.) added a race, leading to possible NULL ptr
dereference.

Since we can now change dst neighbour, we should make sure a reader can
safely use a neighbour.

Add RCU protection to dst neighbour, and make sure check_peer_redir()
can be called safely by different cpus in parallel.

As neighbours are already freed after one RCU grace period, this patch
should not add typical RCU penalty (cache cold effects)

Many thanks to Gergely for providing a pretty report pointing to the
bug.

Reported-by: Gergely Kalman <synapse@hippy.csoma.elte.hu>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Abstract dst->neighbour accesses behind helpers. 2011-07-18T06:11:35+00:00 David S. Miller davem@davemloft.net 2011-07-18T06:09:49+00:00 69cce1d1404968f78b177a0314f5822d5afdbbfb dst_{get,set}_neighbour() Signed-off-by: David S. Miller <davem@davemloft.net> 
dst_{get,set}_neighbour()

Signed-off-by: David S. Miller <davem@davemloft.net>
ipv6: Get rid of rt6i_nexthop macro. 2011-07-18T06:11:35+00:00 David S. Miller davem@davemloft.net 2011-07-18T03:06:13+00:00 9cbb7ecbcff85077bb12301aaf4c9b5a56c5993d It just makes it harder to see 1) what the code is doing and 2) grep for all users of dst{->,.}neighbour Signed-off-by: David S. Miller <davem@davemloft.net> 
It just makes it harder to see 1) what the code is doing
and 2) grep for all users of dst{->,.}neighbour

Signed-off-by: David S. Miller <davem@davemloft.net>
rtnetlink: Compute and store minimum ifinfo dump size 2011-06-10T03:38:07+00:00 Greg Rose gregory.v.rose@intel.com 2011-06-10T01:27:09+00:00 c7ac8679bec9397afe8918f788cbcef88c38da54 The message size allocated for rtnl ifinfo dumps was limited to a single page. This is not enough for additional interface info available with devices that support SR-IOV and caused a bug in which VF info would not be displayed if more than approximately 40 VFs were created per interface. Implement a new function pointer for the rtnl_register service that will calculate the amount of data required for the ifinfo dump and allocate enough data to satisfy the request. Signed-off-by: Greg Rose <gregory.v.rose@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> 
The message size allocated for rtnl ifinfo dumps was limited to
a single page.  This is not enough for additional interface info
available with devices that support SR-IOV and caused a bug in
which VF info would not be displayed if more than approximately
40 VFs were created per interface.

Implement a new function pointer for the rtnl_register service that will
calculate the amount of data required for the ifinfo dump and allocate
enough data to satisfy the request.

Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
net: dont hold rtnl mutex during netlink dump callbacks 2011-05-02T22:26:28+00:00 Eric Dumazet eric.dumazet@gmail.com 2011-04-27T22:56:07+00:00 e67f88dd12f610da98ca838822f2c9b4e7c6100e Four years ago, Patrick made a change to hold rtnl mutex during netlink dump callbacks. I believe it was a wrong move. This slows down concurrent dumps, making good old /proc/net/ files faster than rtnetlink in some situations. This occurred to me because one "ip link show dev ..." was _very_ slow on a workload adding/removing network devices in background. All dump callbacks are able to use RCU locking now, so this patch does roughly a revert of commits : 1c2d670f366 : [RTNETLINK]: Hold rtnl_mutex during netlink dump callbacks 6313c1e0992 : [RTNETLINK]: Remove unnecessary locking in dump callbacks This let writers fight for rtnl mutex and readers going full speed. It also takes care of phonet : phonet_route_get() is now called from rcu read section. I renamed it to phonet_route_get_rcu() Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Patrick McHardy <kaber@trash.net> Cc: Remi Denis-Courmont <remi.denis-courmont@nokia.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Four years ago, Patrick made a change to hold rtnl mutex during netlink
dump callbacks.

I believe it was a wrong move. This slows down concurrent dumps, making
good old /proc/net/ files faster than rtnetlink in some situations.

This occurred to me because one "ip link show dev ..." was _very_ slow
on a workload adding/removing network devices in background.

All dump callbacks are able to use RCU locking now, so this patch does
roughly a revert of commits :

1c2d670f366 : [RTNETLINK]: Hold rtnl_mutex during netlink dump callbacks
6313c1e0992 : [RTNETLINK]: Remove unnecessary locking in dump callbacks

This let writers fight for rtnl mutex and readers going full speed.

It also takes care of phonet : phonet_route_get() is now called from rcu
read section. I renamed it to phonet_route_get_rcu()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
inet: constify ip headers and in6_addr 2011-04-22T18:04:14+00:00 Eric Dumazet eric.dumazet@gmail.com 2011-04-22T04:53:02+00:00 b71d1d426d263b0b6cb5760322efebbfc89d4463 Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers where possible, to make code intention more obvious. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipv6: Convert to use flowi6 where applicable. 2011-03-12T23:08:54+00:00 David S. Miller davem@davemloft.net 2011-03-12T21:22:43+00:00 4c9483b2fb5d2548c3cc1fe03cdd4484ceeb5d1c Signed-off-by: David S. Miller <davem@davemloft.net> 
Signed-off-by: David S. Miller <davem@davemloft.net>
fib: avoid false sharing on fib_table_hash 2010-10-16T18:13:23+00:00 Eric Dumazet eric.dumazet@gmail.com 2010-10-13T08:22:03+00:00 10da66f7552b3c7966c2f4f1f72009fb0b5539ec While doing profile analysis, I found fib_hash_table was sometime in a cache line shared by a possibly often written kernel structure. (CONFIG_IP_ROUTE_MULTIPATH || !CONFIG_IPV6_MULTIPLE_TABLES) It's hard to detect because not easily reproductible. Make sure we allocate a full cache line to keep this shared in all cpus caches. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
While doing profile analysis, I found fib_hash_table was sometime in a
cache line shared by a possibly often written kernel structure.

(CONFIG_IP_ROUTE_MULTIPATH || !CONFIG_IPV6_MULTIPLE_TABLES)

It's hard to detect because not easily reproductible.

Make sure we allocate a full cache line to keep this shared in all cpus
caches.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net-next: remove useless union keyword 2010-06-11T06:31:35+00:00 Changli Gao xiaosuo@gmail.com 2010-06-11T06:31:35+00:00 d8d1f30b95a635dbd610dcc5eb641aca8f4768cf remove useless union keyword in rtable, rt6_info and dn_route. Since there is only one member in a union, the union keyword isn't useful. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
remove useless union keyword in rtable, rt6_info and dn_route.

Since there is only one member in a union, the union keyword isn't useful.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Fix various endianness glitches 2010-04-21T02:06:52+00:00 Eric Dumazet eric.dumazet@gmail.com 2010-04-21T02:06:52+00:00 0eae88f31ca2b88911ce843452054139e028771f Sparse can help us find endianness bugs, but we need to make some cleanups to be able to more easily spot real bugs. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Sparse can help us find endianness bugs, but we need to make some
cleanups to be able to more easily spot real bugs.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>