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/mvpp2 | |
| parent | intel: Remove rcu_read_lock() around XDP program invocation (diff) | |
| download | linux-dev-959ad7ec066d9a61557ad6aedf77ea9b54c82df0.tar.xz linux-dev-959ad7ec066d9a61557ad6aedf77ea9b54c82df0.zip | |
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/mvpp2')
| -rw-r--r-- | drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index 9bca8c8f9f8d..c31677527a02 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -3881,8 +3881,6 @@ static int mvpp2_rx(struct mvpp2_port *port, struct napi_struct *napi, int rx_done = 0; u32 xdp_ret = 0; - rcu_read_lock(); - xdp_prog = READ_ONCE(port->xdp_prog); /* Get number of received packets and clamp the to-do */ @@ -4028,8 +4026,6 @@ err_drop_frame: mvpp2_bm_pool_put(port, pool, dma_addr, phys_addr); } - rcu_read_unlock(); - if (xdp_ret & MVPP2_XDP_REDIR) xdp_do_flush_map(); |