@@ -2558,13 +2558,9 @@ static u32 dpaa_run_xdp(struct dpaa_priv *priv, struct qm_fd *fd, void *vaddr,
u32 xdp_act;
int err;
- rcu_read_lock();
-
xdp_prog = READ_ONCE(priv->xdp_prog);
- if (!xdp_prog) {
- rcu_read_unlock();
+ if (!xdp_prog)
return XDP_PASS;
- }
xdp_init_buff(&xdp, DPAA_BP_RAW_SIZE - DPAA_TX_PRIV_DATA_SIZE,
&dpaa_fq->xdp_rxq);
@@ -2638,8 +2634,6 @@ static u32 dpaa_run_xdp(struct dpaa_priv *priv, struct qm_fd *fd, void *vaddr,
break;
}
- rcu_read_unlock();
-
return xdp_act;
}
@@ -352,8 +352,6 @@ static u32 dpaa2_eth_run_xdp(struct dpaa2_eth_priv *priv,
u32 xdp_act = XDP_PASS;
int err, offset;
- rcu_read_lock();
-
xdp_prog = READ_ONCE(ch->xdp.prog);
if (!xdp_prog)
goto out;
@@ -414,7 +412,6 @@ static u32 dpaa2_eth_run_xdp(struct dpaa2_eth_priv *priv,
ch->xdp.res |= xdp_act;
out:
- rcu_read_unlock();
return xdp_act;
}
The dpaa and dpaa2 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. Cc: Madalin Bucur <madalin.bucur@nxp.com> Cc: Ioana Ciornei <ioana.ciornei@nxp.com> Cc: Ioana Radulescu <ruxandra.radulescu@nxp.com> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> --- drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 8 +------- drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c | 3 --- 2 files changed, 1 insertion(+), 10 deletions(-)