From d4774ac0d49ae92c5176c9848db555e89a5a4e45 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 6 Sep 2019 22:29:58 -0700 Subject: net/tls: use RCU for the adder to the offload record list All modifications to TLS record list happen under the socket lock. Since records form an ordered queue readers are only concerned about elements being removed, additions can happen concurrently. Use RCU primitives to ensure the correct access types (READ_ONCE/WRITE_ONCE). Signed-off-by: Jakub Kicinski Reviewed-by: Dirk van der Merwe Signed-off-by: David S. Miller --- net/tls/tls_device.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'net') diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c index 285c9f9e94e4..b11355e00514 100644 --- a/net/tls/tls_device.c +++ b/net/tls/tls_device.c @@ -280,9 +280,7 @@ static int tls_push_record(struct sock *sk, tls_append_frag(record, &dummy_tag_frag, prot->tag_size); record->end_seq = tp->write_seq + record->len; - spin_lock_irq(&offload_ctx->lock); - list_add_tail(&record->list, &offload_ctx->records_list); - spin_unlock_irq(&offload_ctx->lock); + list_add_tail_rcu(&record->list, &offload_ctx->records_list); offload_ctx->open_record = NULL; if (test_bit(TLS_TX_SYNC_SCHED, &ctx->flags)) @@ -535,12 +533,16 @@ struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context, /* if retransmit_hint is irrelevant start * from the beggining of the list */ - info = list_first_entry(&context->records_list, - struct tls_record_info, list); + info = list_first_entry_or_null(&context->records_list, + struct tls_record_info, list); + if (!info) + return NULL; record_sn = context->unacked_record_sn; } - list_for_each_entry_from(info, &context->records_list, list) { + /* We just need the _rcu for the READ_ONCE() */ + rcu_read_lock(); + list_for_each_entry_from_rcu(info, &context->records_list, list) { if (before(seq, info->end_seq)) { if (!context->retransmit_hint || after(info->end_seq, @@ -549,12 +551,15 @@ struct tls_record_info *tls_get_record(struct tls_offload_context_tx *context, context->retransmit_hint = info; } *p_record_sn = record_sn; - return info; + goto exit_rcu_unlock; } record_sn++; } + info = NULL; - return NULL; +exit_rcu_unlock: + rcu_read_unlock(); + return info; } EXPORT_SYMBOL(tls_get_record); -- cgit v1.2.3