diff options
| author | Toke Høiland-Jørgensen <toke@redhat.com> | 2021-06-24 18:05:59 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-06-24 19:44:02 +0200 |
| commit | 36baafe347a85a9d85f61aac0a9b53c53635829e (patch) | |
| tree | edcad54526c97cfef56d152c7512ddf4bebfa822 /drivers/net | |
| parent | 158c1399fc45c5178a3f2b8b68ff2faa2e36a52d (diff) | |
thunderx: Remove rcu_read_lock() around XDP program invocation
The thunderx 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. 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: Sunil Goutham <sgoutham@marvell.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/bpf/20210624160609.292325-10-toke@redhat.com
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/ethernet/cavium/thunder/nicvf_main.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c index c33b4e837515..e2b290135fd9 100644 --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c @@ -555,9 +555,7 @@ static inline bool nicvf_xdp_rx(struct nicvf *nic, struct bpf_prog *prog, xdp_prepare_buff(&xdp, hard_start, data - hard_start, len, false); orig_data = xdp.data; - rcu_read_lock(); action = bpf_prog_run_xdp(prog, &xdp); - rcu_read_unlock(); len = xdp.data_end - xdp.data; /* Check if XDP program has changed headers */ |