diff options
| -rw-r--r-- | include/net/sock.h | 32 | ||||
| -rw-r--r-- | net/core/sock.c | 20 |
2 files changed, 37 insertions, 15 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index 4bb1ff9fd15..9bebcd78c4c 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -103,15 +103,15 @@ struct net; /** * struct sock_common - minimal network layer representation of sockets + * @skc_node: main hash linkage for various protocol lookup tables + * @skc_nulls_node: main hash linkage for UDP/UDP-Lite protocol + * @skc_refcnt: reference count + * @skc_hash: hash value used with various protocol lookup tables * @skc_family: network address family * @skc_state: Connection state * @skc_reuse: %SO_REUSEADDR setting * @skc_bound_dev_if: bound device index if != 0 - * @skc_node: main hash linkage for various protocol lookup tables - * @skc_nulls_node: main hash linkage for UDP/UDP-Lite protocol * @skc_bind_node: bind hash linkage for various protocol lookup tables - * @skc_refcnt: reference count - * @skc_hash: hash value used with various protocol lookup tables * @skc_prot: protocol handlers inside a network family * @skc_net: reference to the network namespace of this socket * @@ -119,17 +119,21 @@ struct net; * for struct sock and struct inet_timewait_sock. */ struct sock_common { - unsigned short skc_family; - volatile unsigned char skc_state; - unsigned char skc_reuse; - int skc_bound_dev_if; + /* + * first fields are not copied in sock_copy() + */ union { struct hlist_node skc_node; struct hlist_nulls_node skc_nulls_node; }; - struct hlist_node skc_bind_node; atomic_t skc_refcnt; + unsigned int skc_hash; + unsigned short skc_family; + volatile unsigned char skc_state; + unsigned char skc_reuse; + int skc_bound_dev_if; + struct hlist_node skc_bind_node; struct proto *skc_prot; #ifdef CONFIG_NET_NS struct net *skc_net; @@ -207,15 +211,17 @@ struct sock { * don't add nothing before this first member (__sk_common) --acme */ struct sock_common __sk_common; +#define sk_node __sk_common.skc_node +#define sk_nulls_node __sk_common.skc_nulls_node +#define sk_refcnt __sk_common.skc_refcnt + +#define sk_copy_start __sk_common.skc_hash +#define sk_hash __sk_common.skc_hash #define sk_family __sk_common.skc_family #define sk_state __sk_common.skc_state #define sk_reuse __sk_common.skc_reuse #define sk_bound_dev_if __sk_common.skc_bound_dev_if -#define sk_node __sk_common.skc_node -#define sk_nulls_node __sk_common.skc_nulls_node #define sk_bind_node __sk_common.skc_bind_node -#define sk_refcnt __sk_common.skc_refcnt -#define sk_hash __sk_common.skc_hash #define sk_prot __sk_common.skc_prot #define sk_net __sk_common.skc_net unsigned char sk_shutdown : 2, diff --git a/net/core/sock.c b/net/core/sock.c index 08e164568b6..3f5e77e728e 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -915,13 +915,19 @@ static inline void sock_lock_init(struct sock *sk) af_family_keys + sk->sk_family); } +/* + * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet, + * even temporarly, because of RCU lookups. sk_node should also be left as is. + */ static void sock_copy(struct sock *nsk, const struct sock *osk) { #ifdef CONFIG_SECURITY_NETWORK void *sptr = nsk->sk_security; #endif - - memcpy(nsk, osk, osk->sk_prot->obj_size); + BUILD_BUG_ON(offsetof(struct sock, sk_copy_start) != + sizeof(osk->sk_node) + sizeof(osk->sk_refcnt)); + memcpy(&nsk->sk_copy_start, &osk->sk_copy_start, + osk->sk_prot->obj_size - offsetof(struct sock, sk_copy_start)); #ifdef CONFIG_SECURITY_NETWORK nsk->sk_security = sptr; security_sk_clone(osk, nsk); @@ -1118,6 +1124,11 @@ struct sock *sk_clone(const struct sock *sk, const gfp_t priority) newsk->sk_err = 0; newsk->sk_priority = 0; + /* + * Before updating sk_refcnt, we must commit prior changes to memory + * (Documentation/RCU/rculist_nulls.txt for details) + */ + smp_wmb(); atomic_set(&newsk->sk_refcnt, 2); /* @@ -1809,6 +1820,11 @@ void sock_init_data(struct socket *sock, struct sock *sk) sk->sk_stamp = ktime_set(-1L, 0); + /* + * Before updating sk_refcnt, we must commit prior changes to memory + * (Documentation/RCU/rculist_nulls.txt for details) + */ + smp_wmb(); atomic_set(&sk->sk_refcnt, 1); atomic_set(&sk->sk_drops, 0); } |