From: Antonio Quartulli <a@unstable.cc> To: davem@davemloft.net Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org, Sven Eckelmann <sven@narfation.org>, Marek Lindner <mareklindner@neomailbox.ch>, Antonio Quartulli <a@unstable.cc> Subject: [PATCH 6/8] batman-adv: Drop immediate neigh_ifinfo free function Date: Sun, 17 Jan 2016 13:24:39 +0800 [thread overview] Message-ID: <1453008281-15396-7-git-send-email-a@unstable.cc> (raw) In-Reply-To: <1453008281-15396-1-git-send-email-a@unstable.cc> From: Sven Eckelmann <sven@narfation.org> It is not allowed to free the memory of an object which is part of a list which is protected by rcu-read-side-critical sections without making sure that no other context is accessing the object anymore. This usually happens by removing the references to this object and then waiting until the rcu grace period is over and no one (allowedly) accesses it anymore. But the _now functions ignore this completely. They free the object directly even when a different context still tries to access it. This has to be avoided and thus these functions must be removed and all functions have to use batadv_neigh_ifinfo_free_ref. Fixes: 89652331c00f ("batman-adv: split tq information in neigh_node struct") Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <a@unstable.cc> --- net/batman-adv/originator.c | 34 ++++++++++------------------------ 1 file changed, 10 insertions(+), 24 deletions(-) diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 0b7ab38e74fc..f68333586681 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -163,42 +163,28 @@ err: } /** - * batadv_neigh_ifinfo_free_rcu - free the neigh_ifinfo object - * @rcu: rcu pointer of the neigh_ifinfo object - */ -static void batadv_neigh_ifinfo_free_rcu(struct rcu_head *rcu) -{ - struct batadv_neigh_ifinfo *neigh_ifinfo; - - neigh_ifinfo = container_of(rcu, struct batadv_neigh_ifinfo, rcu); - - if (neigh_ifinfo->if_outgoing != BATADV_IF_DEFAULT) - batadv_hardif_free_ref_now(neigh_ifinfo->if_outgoing); - - kfree(neigh_ifinfo); -} - -/** - * batadv_neigh_ifinfo_free_now - decrement the refcounter and possibly free - * the neigh_ifinfo (without rcu callback) + * batadv_neigh_ifinfo_release - release neigh_ifinfo from lists and queue for + * free after rcu grace period * @neigh_ifinfo: the neigh_ifinfo object to release */ static void -batadv_neigh_ifinfo_free_ref_now(struct batadv_neigh_ifinfo *neigh_ifinfo) +batadv_neigh_ifinfo_release(struct batadv_neigh_ifinfo *neigh_ifinfo) { - if (atomic_dec_and_test(&neigh_ifinfo->refcount)) - batadv_neigh_ifinfo_free_rcu(&neigh_ifinfo->rcu); + if (neigh_ifinfo->if_outgoing != BATADV_IF_DEFAULT) + batadv_hardif_free_ref(neigh_ifinfo->if_outgoing); + + kfree_rcu(neigh_ifinfo, rcu); } /** - * batadv_neigh_ifinfo_free_ref - decrement the refcounter and possibly free + * batadv_neigh_ifinfo_free_ref - decrement the refcounter and possibly release * the neigh_ifinfo * @neigh_ifinfo: the neigh_ifinfo object to release */ void batadv_neigh_ifinfo_free_ref(struct batadv_neigh_ifinfo *neigh_ifinfo) { if (atomic_dec_and_test(&neigh_ifinfo->refcount)) - call_rcu(&neigh_ifinfo->rcu, batadv_neigh_ifinfo_free_rcu); + batadv_neigh_ifinfo_release(neigh_ifinfo); } /** @@ -245,7 +231,7 @@ static void batadv_neigh_node_free_rcu(struct rcu_head *rcu) hlist_for_each_entry_safe(neigh_ifinfo, node_tmp, &neigh_node->ifinfo_list, list) { - batadv_neigh_ifinfo_free_ref_now(neigh_ifinfo); + batadv_neigh_ifinfo_free_ref(neigh_ifinfo); } hardif_neigh = batadv_hardif_neigh_get(neigh_node->if_incoming, -- 2.7.0
WARNING: multiple messages have this Message-ID (diff)
From: Antonio Quartulli <a@unstable.cc> To: davem@davemloft.net Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org, Antonio Quartulli <a@unstable.cc>, Marek Lindner <mareklindner@neomailbox.ch> Subject: [B.A.T.M.A.N.] [PATCH 6/8] batman-adv: Drop immediate neigh_ifinfo free function Date: Sun, 17 Jan 2016 13:24:39 +0800 [thread overview] Message-ID: <1453008281-15396-7-git-send-email-a@unstable.cc> (raw) In-Reply-To: <1453008281-15396-1-git-send-email-a@unstable.cc> From: Sven Eckelmann <sven@narfation.org> It is not allowed to free the memory of an object which is part of a list which is protected by rcu-read-side-critical sections without making sure that no other context is accessing the object anymore. This usually happens by removing the references to this object and then waiting until the rcu grace period is over and no one (allowedly) accesses it anymore. But the _now functions ignore this completely. They free the object directly even when a different context still tries to access it. This has to be avoided and thus these functions must be removed and all functions have to use batadv_neigh_ifinfo_free_ref. Fixes: 89652331c00f ("batman-adv: split tq information in neigh_node struct") Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <a@unstable.cc> --- net/batman-adv/originator.c | 34 ++++++++++------------------------ 1 file changed, 10 insertions(+), 24 deletions(-) diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 0b7ab38e74fc..f68333586681 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -163,42 +163,28 @@ err: } /** - * batadv_neigh_ifinfo_free_rcu - free the neigh_ifinfo object - * @rcu: rcu pointer of the neigh_ifinfo object - */ -static void batadv_neigh_ifinfo_free_rcu(struct rcu_head *rcu) -{ - struct batadv_neigh_ifinfo *neigh_ifinfo; - - neigh_ifinfo = container_of(rcu, struct batadv_neigh_ifinfo, rcu); - - if (neigh_ifinfo->if_outgoing != BATADV_IF_DEFAULT) - batadv_hardif_free_ref_now(neigh_ifinfo->if_outgoing); - - kfree(neigh_ifinfo); -} - -/** - * batadv_neigh_ifinfo_free_now - decrement the refcounter and possibly free - * the neigh_ifinfo (without rcu callback) + * batadv_neigh_ifinfo_release - release neigh_ifinfo from lists and queue for + * free after rcu grace period * @neigh_ifinfo: the neigh_ifinfo object to release */ static void -batadv_neigh_ifinfo_free_ref_now(struct batadv_neigh_ifinfo *neigh_ifinfo) +batadv_neigh_ifinfo_release(struct batadv_neigh_ifinfo *neigh_ifinfo) { - if (atomic_dec_and_test(&neigh_ifinfo->refcount)) - batadv_neigh_ifinfo_free_rcu(&neigh_ifinfo->rcu); + if (neigh_ifinfo->if_outgoing != BATADV_IF_DEFAULT) + batadv_hardif_free_ref(neigh_ifinfo->if_outgoing); + + kfree_rcu(neigh_ifinfo, rcu); } /** - * batadv_neigh_ifinfo_free_ref - decrement the refcounter and possibly free + * batadv_neigh_ifinfo_free_ref - decrement the refcounter and possibly release * the neigh_ifinfo * @neigh_ifinfo: the neigh_ifinfo object to release */ void batadv_neigh_ifinfo_free_ref(struct batadv_neigh_ifinfo *neigh_ifinfo) { if (atomic_dec_and_test(&neigh_ifinfo->refcount)) - call_rcu(&neigh_ifinfo->rcu, batadv_neigh_ifinfo_free_rcu); + batadv_neigh_ifinfo_release(neigh_ifinfo); } /** @@ -245,7 +231,7 @@ static void batadv_neigh_node_free_rcu(struct rcu_head *rcu) hlist_for_each_entry_safe(neigh_ifinfo, node_tmp, &neigh_node->ifinfo_list, list) { - batadv_neigh_ifinfo_free_ref_now(neigh_ifinfo); + batadv_neigh_ifinfo_free_ref(neigh_ifinfo); } hardif_neigh = batadv_hardif_neigh_get(neigh_node->if_incoming, -- 2.7.0
next prev parent reply other threads:[~2016-01-17 5:27 UTC|newest] Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-01-17 5:24 [B.A.T.M.A.N.] pull request [net]: batman-adv 20160117 Antonio Quartulli 2016-01-17 5:24 ` [PATCH 1/8] batman-adv: Avoid recursive call_rcu for batadv_bla_claim Antonio Quartulli 2016-01-17 5:24 ` [B.A.T.M.A.N.] " Antonio Quartulli 2016-01-17 5:24 ` [B.A.T.M.A.N.] [PATCH 2/8] batman-adv: Avoid recursive call_rcu for batadv_nc_node Antonio Quartulli 2016-01-17 5:24 ` Antonio Quartulli 2016-01-17 5:24 ` [PATCH 3/8] batman-adv: Drop immediate batadv_orig_ifinfo free function Antonio Quartulli 2016-01-17 5:24 ` [B.A.T.M.A.N.] " Antonio Quartulli 2016-01-17 5:24 ` [B.A.T.M.A.N.] [PATCH 4/8] batman-adv: Drop immediate batadv_neigh_node " Antonio Quartulli 2016-01-17 5:24 ` Antonio Quartulli 2016-01-17 5:24 ` [B.A.T.M.A.N.] [PATCH 5/8] batman-adv: Drop immediate batadv_hardif_neigh_node " Antonio Quartulli 2016-01-17 5:24 ` Antonio Quartulli 2016-01-17 5:24 ` Antonio Quartulli [this message] 2016-01-17 5:24 ` [B.A.T.M.A.N.] [PATCH 6/8] batman-adv: Drop immediate neigh_ifinfo " Antonio Quartulli 2016-01-17 5:24 ` [PATCH 7/8] batman-adv: Drop immediate batadv_hard_iface " Antonio Quartulli 2016-01-17 5:24 ` [B.A.T.M.A.N.] " Antonio Quartulli 2016-01-17 5:24 ` [PATCH 8/8] batman-adv: Drop immediate orig_node " Antonio Quartulli 2016-01-17 5:24 ` [B.A.T.M.A.N.] " Antonio Quartulli [not found] ` <1453008281-15396-1-git-send-email-a-2CpIooy/SPIKlTDg6p0iyA@public.gmane.org> 2016-01-17 6:04 ` pull request [net]: batman-adv 20160117 David Miller 2016-01-17 6:04 ` [B.A.T.M.A.N.] " David Miller 2016-01-17 6:12 ` Antonio Quartulli [not found] ` <569B30D0.2040406-2CpIooy/SPIKlTDg6p0iyA@public.gmane.org> 2016-01-17 16:39 ` David Miller 2016-01-17 16:39 ` [B.A.T.M.A.N.] " David Miller 2016-01-17 6:12 ` Antonio Quartulli
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