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| author | Shlomo Pongratz <shlomop@mellanox.com> | 2014-02-02 15:42:10 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-02-04 20:01:55 -0800 |
| commit | a664a4f7aa4f01ca8728e3ec43618327416fc8ff (patch) | |
| tree | 62866bf915a2074380ec6c066ee7330804b39cda | |
| parent | 9330ed16da840b1b68cd99600d403b6f3e9fa4e2 (diff) | |
| download | linux-stable-a664a4f7aa4f01ca8728e3ec43618327416fc8ff.tar.gz linux-stable-a664a4f7aa4f01ca8728e3ec43618327416fc8ff.tar.bz2 linux-stable-a664a4f7aa4f01ca8728e3ec43618327416fc8ff.zip | |
net/ipv4: Use proper RCU APIs for writer-side in udp_offload.c
RCU writer side should use rcu_dereference_protected() and not
rcu_dereference(), fix that. This also removes the "suspicious RCU usage"
warning seen when running with CONFIG_PROVE_RCU.
Also, don't use rcu_assign_pointer/rcu_dereference for pointers
which are invisible beyond the udp offload code.
Fixes: b582ef0 ('net: Add GRO support for UDP encapsulating protocols')
Reported-by: Eric Dumazet <edumazet@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/udp_offload.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 2ffea6f31efc..88b4023ecfcf 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -17,6 +17,8 @@ static DEFINE_SPINLOCK(udp_offload_lock); static struct udp_offload_priv __rcu *udp_offload_base __read_mostly; +#define udp_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&udp_offload_lock)) + struct udp_offload_priv { struct udp_offload *offload; struct rcu_head rcu; @@ -100,7 +102,6 @@ out: int udp_add_offload(struct udp_offload *uo) { - struct udp_offload_priv __rcu **head = &udp_offload_base; struct udp_offload_priv *new_offload = kzalloc(sizeof(*new_offload), GFP_ATOMIC); if (!new_offload) @@ -109,8 +110,8 @@ int udp_add_offload(struct udp_offload *uo) new_offload->offload = uo; spin_lock(&udp_offload_lock); - rcu_assign_pointer(new_offload->next, rcu_dereference(*head)); - rcu_assign_pointer(*head, new_offload); + new_offload->next = udp_offload_base; + rcu_assign_pointer(udp_offload_base, new_offload); spin_unlock(&udp_offload_lock); return 0; @@ -130,12 +131,12 @@ void udp_del_offload(struct udp_offload *uo) spin_lock(&udp_offload_lock); - uo_priv = rcu_dereference(*head); + uo_priv = udp_deref_protected(*head); for (; uo_priv != NULL; - uo_priv = rcu_dereference(*head)) { - + uo_priv = udp_deref_protected(*head)) { if (uo_priv->offload == uo) { - rcu_assign_pointer(*head, rcu_dereference(uo_priv->next)); + rcu_assign_pointer(*head, + udp_deref_protected(uo_priv->next)); goto unlock; } head = &uo_priv->next; |