kernel_optimize_test/net/ipv4
Eric Dumazet 686a7e32ca inetpeer: fix race in unused_list manipulations
Several crashes in cleanup_once() were reported in recent kernels.

Commit d6cc1d642d (inetpeer: various changes) added a race in
unlink_from_unused().

One way to avoid taking unused_peers.lock before doing the list_empty()
test is to catch 0->1 refcnt transitions, using full barrier atomic
operations variants (atomic_cmpxchg() and atomic_inc_return()) instead
of previous atomic_inc() and atomic_add_unless() variants.

We then call unlink_from_unused() only for the owner of the 0->1
transition.

Add a new atomic_add_unless_return() static helper

With help from Arun Sharma.

Refs: https://bugzilla.kernel.org/show_bug.cgi?id=32772

Reported-by: Arun Sharma <asharma@fb.com>
Reported-by: Maximilian Engelhardt <maxi@daemonizer.de>
Reported-by: Yann Dupont <Yann.Dupont@univ-nantes.fr>
Reported-by: Denys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-27 13:39:11 -04:00
..
netfilter
af_inet.c
ah4.c
arp.c
cipso_ipv4.c
datagram.c
devinet.c
esp4.c
fib_frontend.c
fib_lookup.h
fib_rules.c
fib_semantics.c
fib_trie.c
gre.c
icmp.c
igmp.c
inet_connection_sock.c
inet_diag.c
inet_fragment.c
inet_hashtables.c
inet_lro.c
inet_timewait_sock.c
inetpeer.c
ip_forward.c
ip_fragment.c
ip_gre.c
ip_input.c
ip_options.c
ip_output.c
ip_sockglue.c
ipcomp.c
ipconfig.c
ipip.c
ipmr.c
Kconfig
Makefile
netfilter.c
ping.c
proc.c
protocol.c
raw.c
route.c
syncookies.c
sysctl_net_ipv4.c
tcp_bic.c
tcp_cong.c
tcp_cubic.c
tcp_diag.c
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c
tcp_illinois.c
tcp_input.c
tcp_ipv4.c
tcp_lp.c
tcp_minisocks.c
tcp_output.c
tcp_probe.c
tcp_scalable.c
tcp_timer.c
tcp_vegas.c
tcp_vegas.h
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tcp.c
tunnel4.c
udp_impl.h
udp.c
udplite.c
xfrm4_input.c
xfrm4_mode_beet.c
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c
xfrm4_output.c
xfrm4_policy.c
xfrm4_state.c
xfrm4_tunnel.c