From 7b6ee873ff20c22af355661b241defa7f6ed7582 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Thu, 24 Jun 2021 18:06:07 +0200 Subject: [PATCH] netsec: Remove rcu_read_lock() around XDP program invocation MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The netsec driver has a rcu_read_lock()/rcu_read_unlock() pair around the full RX loop, covering everything up to and including xdp_do_flush(). This is actually the correct behaviour, but because it all happens in a single NAPI poll cycle (and thus under local_bh_disable()), it is also technically redundant. With the addition of RCU annotations to the XDP_REDIRECT map types that take bh execution into account, lockdep even understands this to be safe, so there's really no reason to keep the rcu_read_lock() around anymore, so let's just remove it. Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Daniel Borkmann Acked-by: Ilias Apalodimas Cc: Jassi Brar Link: https://lore.kernel.org/bpf/20210624160609.292325-18-toke@redhat.com --- drivers/net/ethernet/socionext/netsec.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/net/ethernet/socionext/netsec.c b/drivers/net/ethernet/socionext/netsec.c index dfc85cc68173c..20d148c019d8d 100644 --- a/drivers/net/ethernet/socionext/netsec.c +++ b/drivers/net/ethernet/socionext/netsec.c @@ -958,7 +958,6 @@ static int netsec_process_rx(struct netsec_priv *priv, int budget) xdp_init_buff(&xdp, PAGE_SIZE, &dring->xdp_rxq); - rcu_read_lock(); xdp_prog = READ_ONCE(priv->xdp_prog); dma_dir = page_pool_get_dma_dir(dring->page_pool); @@ -1069,8 +1068,6 @@ next: } netsec_finalize_xdp_rx(priv, xdp_act, xdp_xmit); - rcu_read_unlock(); - return done; } -- 2.30.2