diff options
| author | Toke Høiland-Jørgensen <toke@redhat.com> | 2021-06-24 19:06:04 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-06-24 20:45:26 +0300 |
| commit | d5789621b658369b21bd13446bab8102cf75df65 (patch) | |
| tree | bc918a2b0cdaa5b22c9bcf5c0bac6b2c3a9ccdda | |
| parent | c4411b371c104e65efb531ebd4d8892c568e3a29 (diff) | |
| download | linux-d5789621b658369b21bd13446bab8102cf75df65.tar.xz | |
nfp: Remove rcu_read_lock() around XDP program invocation
The nfp driver has rcu_read_lock()/rcu_read_unlock() pairs around XDP
program invocations. However, the actual lifetime of the objects referred
by the XDP program invocation is longer, all the way through to the call to
xdp_do_flush(), making the scope of the rcu_read_lock() too small.
While this is not actually an issue for the nfp driver because it doesn't
support XDP_REDIRECT (and thus doesn't call xdp_do_flush()), the
rcu_read_lock() is still unneeded. And 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 it
around.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Cc: oss-drivers@netronome.com
Link: https://lore.kernel.org/bpf/20210624160609.292325-15-toke@redhat.com
| -rw-r--r-- | drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c index eeb30680b4dc..5dfa4799c34f 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c @@ -1819,7 +1819,6 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget) struct xdp_buff xdp; int idx; - rcu_read_lock(); xdp_prog = READ_ONCE(dp->xdp_prog); true_bufsz = xdp_prog ? PAGE_SIZE : dp->fl_bufsz; xdp_init_buff(&xdp, PAGE_SIZE - NFP_NET_RX_BUF_HEADROOM, @@ -2036,7 +2035,6 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget) if (!nfp_net_xdp_complete(tx_ring)) pkts_polled = budget; } - rcu_read_unlock(); return pkts_polled; } |