[PATCH net-next v2 2/5] net: Revert "ipv4: fix a deadlock in ip_ra_control"
flat view
STALE3140d
SUPERSEDED
From: Kirill Tkhai <hidden>
Date: 2018-03-19 09:15:03
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
Status: Superseded by v3 (posted 2018-03-22). [go to v3]
Revision v2 (3 revisions archived).
Revisions (3)
- v1
- v2 current [diff against previous]
- v3 [diff against previous]
This reverts commit 1215e51edad1. Since raw_close() is used on every RAW socket destruction, the changes made by 1215e51edad1 scale sadly. This clearly seen on endless unshare(CLONE_NEWNET) test, and cleanup_net() kwork spends a lot of time waiting for rtnl_lock() introduced by this commit. Next patches in series will rework this in another way, so now we revert 1215e51edad1. Also, it doesn't seen mrtsock_destruct() takes sk_lock, and the comment to the commit does not show the actual stack dump. So, there is a question did we really need in it. Signed-off-by: Kirill Tkhai <redacted> --- net/ipv4/ip_sockglue.c | 1 - net/ipv4/ipmr.c | 11 +++++++++-- net/ipv4/raw.c | 2 -- 3 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index be7c3b71914d..b7bac7351409 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c@@ -594,7 +594,6 @@ static bool setsockopt_needs_rtnl(int optname) case MCAST_LEAVE_GROUP: case MCAST_LEAVE_SOURCE_GROUP: case MCAST_UNBLOCK_SOURCE: - case IP_ROUTER_ALERT: return true; } return false;
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index d752a70855d8..f6be5db16da2 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c@@ -1399,7 +1399,7 @@ static void mrtsock_destruct(struct sock *sk) struct net *net = sock_net(sk); struct mr_table *mrt; - ASSERT_RTNL(); + rtnl_lock(); ipmr_for_each_table(mrt, net) { if (sk == rtnl_dereference(mrt->mroute_sk)) { IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
@@ -1411,6 +1411,7 @@ static void mrtsock_destruct(struct sock *sk) mroute_clean_tables(mrt, false); } } + rtnl_unlock(); } /* Socket options and virtual interface manipulation. The whole
@@ -1475,8 +1476,13 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, if (sk != rcu_access_pointer(mrt->mroute_sk)) { ret = -EACCES; } else { + /* We need to unlock here because mrtsock_destruct takes + * care of rtnl itself and we can't change that due to + * the IP_ROUTER_ALERT setsockopt which runs without it. + */ + rtnl_unlock(); ret = ip_ra_control(sk, 0, NULL); - goto out_unlock; + goto out; } break; case MRT_ADD_VIF:
@@ -1588,6 +1594,7 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, } out_unlock: rtnl_unlock(); +out: return ret; }
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 54648d20bf0f..720bef7da2f6 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c@@ -711,9 +711,7 @@ static void raw_close(struct sock *sk, long timeout) /* * Raw sockets may have direct kernel references. Kill them. */ - rtnl_lock(); ip_ra_control(sk, 0, NULL); - rtnl_unlock(); sk_common_release(sk); }