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authorDavid Howells <dhowells@redhat.com>2017-03-04 03:01:41 +0300
committerDavid S. Miller <davem@davemloft.net>2017-03-08 00:59:06 +0300
commit146d8fef9da1ba854de7fa28b9cb9eb147535f88 (patch)
tree76b9bea4ac0c4bcd1a2c50418a304007b54ad6bd /net/rxrpc/input.c
parent02b2faaf0af1d85585f6d6980e286d53612acfc2 (diff)
downloadlinux-146d8fef9da1ba854de7fa28b9cb9eb147535f88.tar.xz
rxrpc: Call state should be read with READ_ONCE() under some circumstances
The call state may be changed at any time by the data-ready routine in response to received packets, so if the call state is to be read and acted upon several times in a function, READ_ONCE() must be used unless the call state lock is held. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rxrpc/input.c')
-rw-r--r--net/rxrpc/input.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 9f4cfa25af7c..d74921c4969b 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -420,6 +420,7 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb,
u16 skew)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ enum rxrpc_call_state state;
unsigned int offset = sizeof(struct rxrpc_wire_header);
unsigned int ix;
rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0;
@@ -434,14 +435,15 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb,
_proto("Rx DATA %%%u { #%u f=%02x }",
sp->hdr.serial, seq, sp->hdr.flags);
- if (call->state >= RXRPC_CALL_COMPLETE)
+ state = READ_ONCE(call->state);
+ if (state >= RXRPC_CALL_COMPLETE)
return;
/* Received data implicitly ACKs all of the request packets we sent
* when we're acting as a client.
*/
- if ((call->state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
- call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
+ if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
+ state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
!rxrpc_receiving_reply(call))
return;
@@ -799,7 +801,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb,
return rxrpc_proto_abort("AK0", call, 0);
/* Ignore ACKs unless we are or have just been transmitting. */
- switch (call->state) {
+ switch (READ_ONCE(call->state)) {
case RXRPC_CALL_CLIENT_SEND_REQUEST:
case RXRPC_CALL_CLIENT_AWAIT_REPLY:
case RXRPC_CALL_SERVER_SEND_REPLY:
@@ -940,7 +942,7 @@ static void rxrpc_input_call_packet(struct rxrpc_call *call,
static void rxrpc_input_implicit_end_call(struct rxrpc_connection *conn,
struct rxrpc_call *call)
{
- switch (call->state) {
+ switch (READ_ONCE(call->state)) {
case RXRPC_CALL_SERVER_AWAIT_ACK:
rxrpc_call_completed(call);
break;