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author | Daniel Borkmann <daniel@iogearbox.net> | 2016-12-01 00:16:06 +0300 |
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committer | David S. Miller <davem@davemloft.net> | 2016-12-02 19:06:24 +0300 |
commit | 366cbf2f46048d70005c6c33dc289330f24b54b0 (patch) | |
tree | e531d50fe7b94cf8f4f56fdd3c2eff6555f6ef8b /drivers/net/ethernet/qlogic | |
parent | 83a1a1a70e87f676fbb6086b26b6ac7f7fdd107d (diff) | |
download | linux-366cbf2f46048d70005c6c33dc289330f24b54b0.tar.xz |
bpf, xdp: drop rcu_read_lock from bpf_prog_run_xdp and move to caller
After 326fe02d1ed6 ("net/mlx4_en: protect ring->xdp_prog with rcu_read_lock"),
the rcu_read_lock() in bpf_prog_run_xdp() is superfluous, since callers
need to hold rcu_read_lock() already to make sure BPF program doesn't
get released in the background.
Thus, drop it from bpf_prog_run_xdp(), as it can otherwise be misleading.
Still keeping the bpf_prog_run_xdp() is useful as it allows for grepping
in XDP supported drivers and to keep the typecheck on the context intact.
For mlx4, this means we don't have a double rcu_read_lock() anymore. nfp can
just make use of bpf_prog_run_xdp(), too. For qede, just move rcu_read_lock()
out of the helper. When the driver gets atomic replace support, this will
move to call-sites eventually.
mlx5 needs actual fixing as it has the same issue as described already in
326fe02d1ed6 ("net/mlx4_en: protect ring->xdp_prog with rcu_read_lock"),
that is, we're under RCU bh at this time, BPF programs are released via
call_rcu(), and call_rcu() != call_rcu_bh(), so we need to properly mark
read side as programs can get xchg()'ed in mlx5e_xdp_set() without queue
reset.
Fixes: 86994156c736 ("net/mlx5e: XDP fast RX drop bpf programs support")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/qlogic')
-rw-r--r-- | drivers/net/ethernet/qlogic/qede/qede_main.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/net/ethernet/qlogic/qede/qede_main.c b/drivers/net/ethernet/qlogic/qede/qede_main.c index 172ff6da92ad..faeaa9f3b197 100644 --- a/drivers/net/ethernet/qlogic/qede/qede_main.c +++ b/drivers/net/ethernet/qlogic/qede/qede_main.c @@ -1497,7 +1497,14 @@ static bool qede_rx_xdp(struct qede_dev *edev, xdp.data = page_address(bd->data) + cqe->placement_offset; xdp.data_end = xdp.data + len; + + /* 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(); if (act == XDP_PASS) return true; |