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authorMaxim Mikityanskiy <maximmi@mellanox.com>2019-12-17 16:20:45 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-01-12 12:21:42 +0100
commit4f5954a9258311468eb1afb7a60e4e9c1e4f4a19 (patch)
tree416d9615c620fe867a298bceb534e400e7948f9f
parentdf620e3d7d72f8f6d876adcb80fbb8cbd6cdf2fe (diff)
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net/i40e: Fix concurrency issues between config flow and XSK
[ Upstream commit b3873a5be757b44d51af542a50a6f2a3b6f95284 ] Use synchronize_rcu to wait until the XSK wakeup function finishes before destroying the resources it uses: 1. i40e_down already calls synchronize_rcu. On i40e_down either __I40E_VSI_DOWN or __I40E_CONFIG_BUSY is set. Check the latter in i40e_xsk_wakeup (the former is already checked there). 2. After switching the XDP program, call synchronize_rcu to let i40e_xsk_wakeup exit before the XDP program is freed. 3. Changing the number of channels brings the interface down (see i40e_prep_for_reset and i40e_pf_quiesce_all_vsi). 4. Disabling UMEM sets __I40E_CONFIG_BUSY, too. Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191217162023.16011-4-maximmi@mellanox.com Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/net/ethernet/intel/i40e/i40e.h2
-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_main.c10
-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_xsk.c4
3 files changed, 12 insertions, 4 deletions
diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index 2af9f6308f84..401304d4d553 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -1151,7 +1151,7 @@ void i40e_set_fec_in_flags(u8 fec_cfg, u32 *flags);
static inline bool i40e_enabled_xdp_vsi(struct i40e_vsi *vsi)
{
- return !!vsi->xdp_prog;
+ return !!READ_ONCE(vsi->xdp_prog);
}
int i40e_create_queue_channel(struct i40e_vsi *vsi, struct i40e_channel *ch);
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 339925af0206..4960c9c3e773 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -6804,8 +6804,8 @@ void i40e_down(struct i40e_vsi *vsi)
for (i = 0; i < vsi->num_queue_pairs; i++) {
i40e_clean_tx_ring(vsi->tx_rings[i]);
if (i40e_enabled_xdp_vsi(vsi)) {
- /* Make sure that in-progress ndo_xdp_xmit
- * calls are completed.
+ /* Make sure that in-progress ndo_xdp_xmit and
+ * ndo_xsk_wakeup calls are completed.
*/
synchronize_rcu();
i40e_clean_tx_ring(vsi->xdp_rings[i]);
@@ -12526,8 +12526,12 @@ static int i40e_xdp_setup(struct i40e_vsi *vsi,
old_prog = xchg(&vsi->xdp_prog, prog);
- if (need_reset)
+ if (need_reset) {
+ if (!prog)
+ /* Wait until ndo_xsk_wakeup completes. */
+ synchronize_rcu();
i40e_reset_and_rebuild(pf, true, true);
+ }
for (i = 0; i < vsi->num_queue_pairs; i++)
WRITE_ONCE(vsi->rx_rings[i]->xdp_prog, vsi->xdp_prog);
diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index d07e1a890428..f73cd917c44f 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -787,8 +787,12 @@ int i40e_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags)
{
struct i40e_netdev_priv *np = netdev_priv(dev);
struct i40e_vsi *vsi = np->vsi;
+ struct i40e_pf *pf = vsi->back;
struct i40e_ring *ring;
+ if (test_bit(__I40E_CONFIG_BUSY, pf->state))
+ return -ENETDOWN;
+
if (test_bit(__I40E_VSI_DOWN, vsi->state))
return -ENETDOWN;