diff options
| author |   Toke Høiland-Jørgensen <toke@redhat.com> | 2021-06-24 18:06:05 +0200 |
|---|---|---|
| committer |   Daniel Borkmann <daniel@iogearbox.net> | 2021-06-24 19:45:39 +0200 |
| commit | 4415db6ca85ae57830a83290388f2b9dfa5f237f (patch) | |
| tree | 4aebaecb2b573bc46a658c3bada8b2385fe68638 | |
| parent | nfp: Remove rcu_read_lock() around XDP program invocation (diff) | |
| download | linux-4415db6ca85ae57830a83290388f2b9dfa5f237f.tar.xz linux-4415db6ca85ae57830a83290388f2b9dfa5f237f.zip | |
qede: Remove rcu_read_lock() around XDP program invocation
The qede 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: Ariel Elior <aelior@marvell.com>
Cc: gr-everest-linux-l2@marvell.com
Link: https://lore.kernel.org/bpf/20210624160609.292325-16-toke@redhat.com
| -rw-r--r-- | drivers/net/ethernet/qlogic/qede/qede_fp.c | 6 |
1 files changed, 0 insertions, 6 deletions
diff --git a/drivers/net/ethernet/qlogic/qede/qede_fp.c b/drivers/net/ethernet/qlogic/qede/qede_fp.c index 8e150dd4f899..065e9004598e 100644 --- a/drivers/net/ethernet/qlogic/qede/qede_fp.c +++ b/drivers/net/ethernet/qlogic/qede/qede_fp.c @@ -1089,13 +1089,7 @@ static bool qede_rx_xdp(struct qede_dev *edev, xdp_prepare_buff(&xdp, page_address(bd->data), *data_offset, *len, false); - /* Queues always have a full reset currently, so for the time - * being until there's atomic program replace just mark read - * side for map helpers. - */ - rcu_read_lock(); act = bpf_prog_run_xdp(prog, &xdp); - rcu_read_unlock(); /* Recalculate, as XDP might have changed the headers */ *data_offset = xdp.data - xdp.data_hard_start; |