diff --git a/include/linux/bpf.h b/include/linux/bpf.h index a627a02cf8ab79fedf897066625b884d3ed151dd..39bd36359c1ec8bbf7fa289dabe20fe03380f10d 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1966,6 +1966,15 @@ static inline bool unprivileged_ebpf_enabled(void) return !sysctl_unprivileged_bpf_disabled; } +/* Not all bpf prog type has the bpf_ctx. + * For the bpf prog type that has initialized the bpf_ctx, + * this function can be used to decide if a kernel function + * is called by a bpf program. + */ +static inline bool has_current_bpf_ctx(void) +{ + return !!current->bpf_ctx; +} #else /* !CONFIG_BPF_SYSCALL */ static inline struct bpf_prog *bpf_prog_get(u32 ufd) { @@ -2175,6 +2184,10 @@ static inline bool unprivileged_ebpf_enabled(void) return false; } +static inline bool has_current_bpf_ctx(void) +{ + return false; +} #endif /* CONFIG_BPF_SYSCALL */ void __bpf_free_used_btfs(struct bpf_prog_aux *aux, diff --git a/include/net/sock.h b/include/net/sock.h index 05a1bbdf58054d149f1ff8be8a4ffae827bb9be9..352b9458fdc656f4536e3a88ced8c8b1dde231e7 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1749,6 +1749,9 @@ static inline void unlock_sock_fast(struct sock *sk, bool slow) } } +void sockopt_lock_sock(struct sock *sk); +void sockopt_release_sock(struct sock *sk); + /* Used by processes to "lock" a socket state, so that * interrupts and bottom half handlers won't change it * from under us. It essentially blocks any incoming diff --git a/net/core/sock.c b/net/core/sock.c index 20269c37ab3bf900292c25e337d2a68711cc7185..d3683228376f10fae2a667b456935f80623db7d1 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -703,7 +703,9 @@ static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen) goto out; } - return sock_bindtoindex(sk, index, true); + sockopt_lock_sock(sk); + ret = sock_bindtoindex_locked(sk, index); + sockopt_release_sock(sk); out: #endif @@ -1036,6 +1038,28 @@ static int sock_reserve_memory(struct sock *sk, int bytes) return 0; } +void sockopt_lock_sock(struct sock *sk) +{ + /* When current->bpf_ctx is set, the setsockopt is called from + * a bpf prog. bpf has ensured the sk lock has been + * acquired before calling setsockopt(). + */ + if (has_current_bpf_ctx()) + return; + + lock_sock(sk); +} +EXPORT_SYMBOL(sockopt_lock_sock); + +void sockopt_release_sock(struct sock *sk) +{ + if (has_current_bpf_ctx()) + return; + + release_sock(sk); +} +EXPORT_SYMBOL(sockopt_release_sock); + /* * This is meant for all protocols to use and covers goings on * at the socket level. Everything here is generic. @@ -1067,7 +1091,7 @@ static int sk_setsockopt(struct sock *sk, int level, int optname, valbool = val ? 1 : 0; - lock_sock(sk); + sockopt_lock_sock(sk); switch (optname) { case SO_DEBUG: @@ -1496,7 +1520,7 @@ static int sk_setsockopt(struct sock *sk, int level, int optname, ret = -ENOPROTOOPT; break; } - release_sock(sk); + sockopt_release_sock(sk); return ret; }