From: Maxim Mikityanskiy maximmi@nvidia.com
[ Upstream commit 05fc8b6cbd4f979a6f25759c4a17dd5f657f7ecd ]
RCU synchronization is guaranteed to finish in finite time, unlike a busy loop that polls a flag. This patch is a preparation for the bugfix in the next patch, where the same synchronize_net() call will also be used to sync with the TX datapath.
Signed-off-by: Maxim Mikityanskiy maximmi@nvidia.com Reviewed-by: Tariq Toukan tariqt@nvidia.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/tls.h | 1 - net/tls/tls_device.c | 10 +++------- 2 files changed, 3 insertions(+), 8 deletions(-)
diff --git a/include/net/tls.h b/include/net/tls.h index 2bdd802212fe..d32a06705587 100644 --- a/include/net/tls.h +++ b/include/net/tls.h @@ -193,7 +193,6 @@ struct tls_offload_context_tx { (sizeof(struct tls_offload_context_tx) + TLS_DRIVER_STATE_SIZE_TX)
enum tls_context_flags { - TLS_RX_SYNC_RUNNING = 0, /* Unlike RX where resync is driven entirely by the core in TX only * the driver knows when things went out of sync, so we need the flag * to be atomic. diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c index a3ab2d3d4e4e..abc04045577d 100644 --- a/net/tls/tls_device.c +++ b/net/tls/tls_device.c @@ -680,15 +680,13 @@ static void tls_device_resync_rx(struct tls_context *tls_ctx, struct tls_offload_context_rx *rx_ctx = tls_offload_ctx_rx(tls_ctx); struct net_device *netdev;
- if (WARN_ON(test_and_set_bit(TLS_RX_SYNC_RUNNING, &tls_ctx->flags))) - return; - trace_tls_device_rx_resync_send(sk, seq, rcd_sn, rx_ctx->resync_type); + rcu_read_lock(); netdev = READ_ONCE(tls_ctx->netdev); if (netdev) netdev->tlsdev_ops->tls_dev_resync(netdev, sk, seq, rcd_sn, TLS_OFFLOAD_CTX_DIR_RX); - clear_bit_unlock(TLS_RX_SYNC_RUNNING, &tls_ctx->flags); + rcu_read_unlock(); TLS_INC_STATS(sock_net(sk), LINUX_MIB_TLSRXDEVICERESYNC); }
@@ -1298,9 +1296,7 @@ static int tls_device_down(struct net_device *netdev) netdev->tlsdev_ops->tls_dev_del(netdev, ctx, TLS_OFFLOAD_CTX_DIR_RX); WRITE_ONCE(ctx->netdev, NULL); - smp_mb__before_atomic(); /* pairs with test_and_set_bit() */ - while (test_bit(TLS_RX_SYNC_RUNNING, &ctx->flags)) - usleep_range(10, 200); + synchronize_net(); dev_put(netdev); list_del_init(&ctx->list);