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| author | Daniel Borkmann <daniel@iogearbox.net> | 2020-02-05 22:06:09 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-02-05 22:06:12 +0100 |
| commit | b9e42724888527352604260abc6717cba21421de (patch) | |
| tree | d664c62878db152984cb9317a94e5d858515542b | |
| parent | fc9e34f8de001c92e6cfc6481bb30a34dbda4f5c (diff) | |
| parent | 8ed47e140867a6e7d56170f325c8d4fdee6d6b66 (diff) | |
| download | linux-oxnas-b9e42724888527352604260abc6717cba21421de.tar.gz | |
Merge branch 'bpf-xsk-fixes'
Maciej Fijalkowski says:
====================
Cameron reported [0] that on fresh bpf-next he could not run multiple
xdpsock instances in Tx-only mode on single network interface with i40e
driver.
Turns out that Maxim's series [1] which was adding RCU protection around
ndo_xsk_wakeup added check against the __I40E_CONFIG_BUSY being set on
pf->state within i40e_xsk_wakeup() - if it's set, return -ENETDOWN.
Since this bit is set per PF when UMEM is being enabled/disabled, the
situation Cameron stumbled upon was that when he launched second xdpsock
instance, second UMEM was being registered, hence set __I40E_CONFIG_BUSY
which is now observed by first xdpsock and therefore xdpsock's kick_tx()
gets -ENETDOWN as errno.
-ENETDOWN currently is not allowed in kick_tx(), so we were exiting the
first application. Such exit means also XDP program being unloaded and
its dedicated resources, which caused an -ENXIO being return in the
second xdpsock instance.
Let's fix the issue from both sides - protect ourselves from future
xdpsock crashes by allowing for -ENETDOWN errno being set in kick_tx()
(patch 3) and from driver side, return -EAGAIN for the case where PF is
busy (patch 1).
Remove also doubled variable from xdpsock_user.c (patch 2).
Note that ixgbe seems not to be affected since UMEM registration sets
the busy/disable bit per ring, not per PF.
[0]: https://www.spinics.net/lists/xdp-newbies/msg01558.html
[1]: https://lore.kernel.org/netdev/20191217162023.16011-1-maximmi@mellanox.com/
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| -rw-r--r-- | drivers/net/ethernet/intel/i40e/i40e_xsk.c | 2 | ||||
| -rw-r--r-- | samples/bpf/xdpsock_user.c | 4 |
2 files changed, 3 insertions, 3 deletions
diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c index 42058fad6a3cb1..0b7d29192b2cc0 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c @@ -791,7 +791,7 @@ int i40e_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags) struct i40e_ring *ring; if (test_bit(__I40E_CONFIG_BUSY, pf->state)) - return -ENETDOWN; + return -EAGAIN; if (test_bit(__I40E_VSI_DOWN, vsi->state)) return -ENETDOWN; diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index 0b5acd7223062a..c91e91362a0c64 100644 --- a/samples/bpf/xdpsock_user.c +++ b/samples/bpf/xdpsock_user.c @@ -83,7 +83,6 @@ static u32 opt_xdp_bind_flags = XDP_USE_NEED_WAKEUP; static u32 opt_umem_flags; static int opt_unaligned_chunks; static int opt_mmap_flags; -static u32 opt_xdp_bind_flags; static int opt_xsk_frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE; static int opt_timeout = 1000; static bool opt_need_wakeup = true; @@ -789,7 +788,8 @@ static void kick_tx(struct xsk_socket_info *xsk) int ret; ret = sendto(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, 0); - if (ret >= 0 || errno == ENOBUFS || errno == EAGAIN || errno == EBUSY) + if (ret >= 0 || errno == ENOBUFS || errno == EAGAIN || + errno == EBUSY || errno == ENETDOWN) return; exit_with_error(errno); } |