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authorJakub Sitnicki <jakub@cloudflare.com>2020-03-17 18:04:39 +0100
committerDavid S. Miller <davem@davemloft.net>2020-03-21 20:08:17 -0700
commitd5bee7374b68de3c44586d46e9e61ffc97a1e886 (patch)
tree9c1964e017b681e310c7ec48352bd124da90930c
parent5bb4c45d466cb28dd0a7f15f80c4cb7768054e94 (diff)
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net/tls: Annotate access to sk_prot with READ_ONCE/WRITE_ONCE
sockmap performs lockless writes to sk->sk_prot on the following paths: tcp_bpf_{recvmsg|sendmsg} / sock_map_unref sk_psock_put sk_psock_drop sk_psock_restore_proto WRITE_ONCE(sk->sk_prot, proto) To prevent load/store tearing [1], and to make tooling aware of intentional shared access [2], we need to annotate other sites that access sk_prot with READ_ONCE/WRITE_ONCE macros. Change done with Coccinelle with following semantic patch: @@ expression E; identifier I; struct sock *sk; identifier sk_prot =~ "^sk_prot$"; @@ ( E = -sk->sk_prot +READ_ONCE(sk->sk_prot) | -sk->sk_prot = E +WRITE_ONCE(sk->sk_prot, E) | -sk->sk_prot +READ_ONCE(sk->sk_prot) ->I ) Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/tls/tls_device.c2
-rw-r--r--net/tls/tls_main.c9
2 files changed, 6 insertions, 5 deletions
diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 1c5574e2e058..a562ebaaa33c 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -366,7 +366,7 @@ static int tls_do_allocation(struct sock *sk,
if (!offload_ctx->open_record) {
if (unlikely(!skb_page_frag_refill(prepend_size, pfrag,
sk->sk_allocation))) {
- sk->sk_prot->enter_memory_pressure(sk);
+ READ_ONCE(sk->sk_prot)->enter_memory_pressure(sk);
sk_stream_moderate_sndbuf(sk);
return -ENOMEM;
}
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index e7de0306a7df..156efce50dbd 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -69,7 +69,8 @@ void update_sk_prot(struct sock *sk, struct tls_context *ctx)
{
int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
- sk->sk_prot = &tls_prots[ip_ver][ctx->tx_conf][ctx->rx_conf];
+ WRITE_ONCE(sk->sk_prot,
+ &tls_prots[ip_ver][ctx->tx_conf][ctx->rx_conf]);
}
int wait_on_pending_writer(struct sock *sk, long *timeo)
@@ -312,7 +313,7 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
write_lock_bh(&sk->sk_callback_lock);
if (free_ctx)
rcu_assign_pointer(icsk->icsk_ulp_data, NULL);
- sk->sk_prot = ctx->sk_proto;
+ WRITE_ONCE(sk->sk_prot, ctx->sk_proto);
if (sk->sk_write_space == tls_write_space)
sk->sk_write_space = ctx->sk_write_space;
write_unlock_bh(&sk->sk_callback_lock);
@@ -621,14 +622,14 @@ struct tls_context *tls_ctx_create(struct sock *sk)
mutex_init(&ctx->tx_lock);
rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
- ctx->sk_proto = sk->sk_prot;
+ ctx->sk_proto = READ_ONCE(sk->sk_prot);
return ctx;
}
static void tls_build_proto(struct sock *sk)
{
int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4;
- const struct proto *prot = sk->sk_prot;
+ const struct proto *prot = READ_ONCE(sk->sk_prot);
/* Build IPv6 TLS whenever the address of tcpv6 _prot changes */
if (ip_ver == TLSV6 &&