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| author | Toke Høiland-Jørgensen <toke@redhat.com> | 2021-06-24 18:05:58 +0200 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-06-24 19:43:49 +0200 |
| commit | 158c1399fc45c5178a3f2b8b68ff2faa2e36a52d (patch) | |
| tree | c41d324936f5a83ba9d21bc3824f807efd9718bb /drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c | |
| parent | ena: Remove rcu_read_lock() around XDP program invocation (diff) | |
| download | linux-158c1399fc45c5178a3f2b8b68ff2faa2e36a52d.tar.xz linux-158c1399fc45c5178a3f2b8b68ff2faa2e36a52d.zip | |
bnxt: Remove rcu_read_lock() around XDP program invocation
The bnxt 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: Michael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/bpf/20210624160609.292325-9-toke@redhat.com
Diffstat (limited to 'drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c')
| -rw-r--r-- | drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c index ec9564e584e0..bee6e091a997 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c @@ -138,9 +138,7 @@ bool bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons, xdp_prepare_buff(&xdp, *data_ptr - offset, offset, *len, false); orig_data = xdp.data; - rcu_read_lock(); act = bpf_prog_run_xdp(xdp_prog, &xdp); - rcu_read_unlock(); tx_avail = bnxt_tx_avail(bp, txr); /* If the tx ring is not full, we must not update the rx producer yet |