diff options
Diffstat (limited to 'include/net/sock.h')
| -rw-r--r-- | include/net/sock.h | 37 |
1 files changed, 35 insertions, 2 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index 328564525526..b5cca7bae69b 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -527,10 +527,43 @@ enum sk_pacing { SK_PACING_FQ = 2, }; +/* Pointer stored in sk_user_data might not be suitable for copying + * when cloning the socket. For instance, it can point to a reference + * counted object. sk_user_data bottom bit is set if pointer must not + * be copied. + */ +#define SK_USER_DATA_NOCOPY 1UL +#define SK_USER_DATA_PTRMASK ~(SK_USER_DATA_NOCOPY) + +/** + * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied + * @sk: socket + */ +static inline bool sk_user_data_is_nocopy(const struct sock *sk) +{ + return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY); +} + #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data))) -#define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk))) -#define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr) +#define rcu_dereference_sk_user_data(sk) \ +({ \ + void *__tmp = rcu_dereference(__sk_user_data((sk))); \ + (void *)((uintptr_t)__tmp & SK_USER_DATA_PTRMASK); \ +}) +#define rcu_assign_sk_user_data(sk, ptr) \ +({ \ + uintptr_t __tmp = (uintptr_t)(ptr); \ + WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK); \ + rcu_assign_pointer(__sk_user_data((sk)), __tmp); \ +}) +#define rcu_assign_sk_user_data_nocopy(sk, ptr) \ +({ \ + uintptr_t __tmp = (uintptr_t)(ptr); \ + WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK); \ + rcu_assign_pointer(__sk_user_data((sk)), \ + __tmp | SK_USER_DATA_NOCOPY); \ +}) /* * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK |