diff options
| author | Toke Høiland-Jørgensen <toke@redhat.com> | 2021-06-24 18:06:02 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-06-24 19:44:58 +0200 |
| commit | 959ad7ec066d9a61557ad6aedf77ea9b54c82df0 (patch) | |
| tree | 0da9ffd35cdc989ec544db5f85f357044b78d484 /drivers/net/ethernet/marvell/mvneta.c | |
| parent | 49589b23d5a92dff4a7cb705608dff7dd13ef709 (diff) | |
marvell: Remove rcu_read_lock() around XDP program invocation
The mvneta and mvpp2 drivers have 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. This turns out to be harmless because it all happens in a single
NAPI poll cycle (and thus under local_bh_disable()), but it makes the
rcu_read_lock() misleading.
Rather than extend the scope of the rcu_read_lock(), just get rid of it
entirely. 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>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Marcin Wojtas <mw@semihalf.com>
Link: https://lore.kernel.org/bpf/20210624160609.292325-13-toke@redhat.com
Diffstat (limited to 'drivers/net/ethernet/marvell/mvneta.c')
| -rw-r--r-- | drivers/net/ethernet/marvell/mvneta.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index c15ce06427d0..ada4e26a5492 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -2373,7 +2373,6 @@ static int mvneta_rx_swbm(struct napi_struct *napi, /* Get number of received packets */ rx_todo = mvneta_rxq_busy_desc_num_get(pp, rxq); - rcu_read_lock(); xdp_prog = READ_ONCE(pp->xdp_prog); /* Fairness NAPI loop */ @@ -2451,7 +2450,6 @@ next: xdp_buf.data_hard_start = NULL; sinfo.nr_frags = 0; } - rcu_read_unlock(); if (xdp_buf.data_hard_start) mvneta_xdp_put_buff(pp, rxq, &xdp_buf, &sinfo, -1); |