i40e: Fix DMA mappings leak

During reallocation of RX buffers, new DMA mappings are created for
those buffers.

steps for reproduction:
while :
do
for ((i=0; i<=8160; i=i+32))
do
ethtool -G enp130s0f0 rx $i tx $i
sleep 0.5
ethtool -g enp130s0f0
done
done

This resulted in crash:
i40e 0000:01:00.1: Unable to allocate memory for the Rx descriptor ring, size=65536
Driver BUG
WARNING: CPU: 0 PID: 4300 at net/core/xdp.c:141 xdp_rxq_info_unreg+0x43/0x50
Call Trace:
i40e_free_rx_resources+0x70/0x80 [i40e]
i40e_set_ringparam+0x27c/0x800 [i40e]
ethnl_set_rings+0x1b2/0x290
genl_family_rcv_msg_doit.isra.15+0x10f/0x150
genl_family_rcv_msg+0xb3/0x160
? rings_fill_reply+0x1a0/0x1a0
genl_rcv_msg+0x47/0x90
? genl_family_rcv_msg+0x160/0x160
netlink_rcv_skb+0x4c/0x120
genl_rcv+0x24/0x40
netlink_unicast+0x196/0x230
netlink_sendmsg+0x204/0x3d0
sock_sendmsg+0x4c/0x50
__sys_sendto+0xee/0x160
? handle_mm_fault+0xbe/0x1e0
? syscall_trace_enter+0x1d3/0x2c0
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x5b/0x1a0
entry_SYSCALL_64_after_hwframe+0x65/0xca
RIP: 0033:0x7f5eac8b035b
Missing register, driver bug
WARNING: CPU: 0 PID: 4300 at net/core/xdp.c:119 xdp_rxq_info_unreg_mem_model+0x69/0x140
Call Trace:
xdp_rxq_info_unreg+0x1e/0x50
i40e_free_rx_resources+0x70/0x80 [i40e]
i40e_set_ringparam+0x27c/0x800 [i40e]
ethnl_set_rings+0x1b2/0x290
genl_family_rcv_msg_doit.isra.15+0x10f/0x150
genl_family_rcv_msg+0xb3/0x160
? rings_fill_reply+0x1a0/0x1a0
genl_rcv_msg+0x47/0x90
? genl_family_rcv_msg+0x160/0x160
netlink_rcv_skb+0x4c/0x120
genl_rcv+0x24/0x40
netlink_unicast+0x196/0x230
netlink_sendmsg+0x204/0x3d0
sock_sendmsg+0x4c/0x50
__sys_sendto+0xee/0x160
? handle_mm_fault+0xbe/0x1e0
? syscall_trace_enter+0x1d3/0x2c0
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x5b/0x1a0
entry_SYSCALL_64_after_hwframe+0x65/0xca
RIP: 0033:0x7f5eac8b035b

This was caused because of new buffers with different RX ring count should
substitute older ones, but those buffers were freed in
i40e_configure_rx_ring and reallocated again with i40e_alloc_rx_bi,
thus kfree on rx_bi caused leak of already mapped DMA.

Fix this by reallocating ZC with rx_bi_zc struct when BPF program loads. Additionally
reallocate back to rx_bi when BPF program unloads.

If BPF program is loaded/unloaded and XSK pools are created, reallocate
RX queues accordingly in XSP_SETUP_XSK_POOL handler.

Fixes: be1222b585fd ("i40e: Separate kernel allocated rx_bi rings from AF_XDP rings")
Signed-off-by: Jan Sokolowski <jan.sokolowski@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Chandan <chandanx.rout@intel.com> (A Contingent Worker at Intel)
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
index 7e75706..87f36d1 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
@@ -2183,9 +2183,6 @@ static int i40e_set_ringparam(struct net_device *netdev,
                        err = i40e_setup_rx_descriptors(&rx_rings[i]);
                        if (err)
                                goto rx_unwind;
-                       err = i40e_alloc_rx_bi(&rx_rings[i]);
-                       if (err)
-                               goto rx_unwind;
 
                        /* now allocate the Rx buffers to make sure the OS
                         * has enough memory, any failure here means abort

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 2c07fa8..b5dcd15 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3566,12 +3566,8 @@ static int i40e_configure_rx_ring(struct i40e_ring *ring)
        if (ring->vsi->type == I40E_VSI_MAIN)
                xdp_rxq_info_unreg_mem_model(&ring->xdp_rxq);
 
-       kfree(ring->rx_bi);
        ring->xsk_pool = i40e_xsk_pool(ring);
        if (ring->xsk_pool) {
-               ret = i40e_alloc_rx_bi_zc(ring);
-               if (ret)
-                       return ret;
                ring->rx_buf_len =
                  xsk_pool_get_rx_frame_size(ring->xsk_pool);
                /* For AF_XDP ZC, we disallow packets to span on
@@ -3589,9 +3585,6 @@ static int i40e_configure_rx_ring(struct i40e_ring *ring)
                         ring->queue_index);
 
        } else {
-               ret = i40e_alloc_rx_bi(ring);
-               if (ret)
-                       return ret;
                ring->rx_buf_len = vsi->rx_buf_len;
                if (ring->vsi->type == I40E_VSI_MAIN) {
                        ret = xdp_rxq_info_reg_mem_model(&ring->xdp_rxq,
@@ -13296,6 +13289,14 @@ static int i40e_xdp_setup(struct i40e_vsi *vsi, struct bpf_prog *prog,
                i40e_reset_and_rebuild(pf, true, true);
        }
 
+       if (!i40e_enabled_xdp_vsi(vsi) && prog) {
+               if (i40e_realloc_rx_bi_zc(vsi, true))
+                       return -ENOMEM;
+       } else if (i40e_enabled_xdp_vsi(vsi) && !prog) {
+               if (i40e_realloc_rx_bi_zc(vsi, false))
+                       return -ENOMEM;
+       }
+
        for (i = 0; i < vsi->num_queue_pairs; i++)
                WRITE_ONCE(vsi->rx_rings[i]->xdp_prog, vsi->xdp_prog);
 
@@ -13528,6 +13529,7 @@ int i40e_queue_pair_disable(struct i40e_vsi *vsi, int queue_pair)
 
        i40e_queue_pair_disable_irq(vsi, queue_pair);
        err = i40e_queue_pair_toggle_rings(vsi, queue_pair, false /* off */);
+       i40e_clean_rx_ring(vsi->rx_rings[queue_pair]);
        i40e_queue_pair_toggle_napi(vsi, queue_pair, false /* off */);
        i40e_queue_pair_clean_rings(vsi, queue_pair);
        i40e_queue_pair_reset_stats(vsi, queue_pair);

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 69e67eb..b97c95f 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -1457,14 +1457,6 @@ err:
        return -ENOMEM;
 }
 
-int i40e_alloc_rx_bi(struct i40e_ring *rx_ring)
-{
-       unsigned long sz = sizeof(*rx_ring->rx_bi) * rx_ring->count;
-
-       rx_ring->rx_bi = kzalloc(sz, GFP_KERNEL);
-       return rx_ring->rx_bi ? 0 : -ENOMEM;
-}
-
 static void i40e_clear_rx_bi(struct i40e_ring *rx_ring)
 {
        memset(rx_ring->rx_bi, 0, sizeof(*rx_ring->rx_bi) * rx_ring->count);
@@ -1593,6 +1585,11 @@ int i40e_setup_rx_descriptors(struct i40e_ring *rx_ring)
 
        rx_ring->xdp_prog = rx_ring->vsi->xdp_prog;
 
+       rx_ring->rx_bi =
+               kcalloc(rx_ring->count, sizeof(*rx_ring->rx_bi), GFP_KERNEL);
+       if (!rx_ring->rx_bi)
+               return -ENOMEM;
+
        return 0;
 }
 

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index 41f86e9..768290d 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -469,7 +469,6 @@ int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size);
 bool __i40e_chk_linearize(struct sk_buff *skb);
 int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
                  u32 flags);
-int i40e_alloc_rx_bi(struct i40e_ring *rx_ring);
 
 /**
  * i40e_get_head - Retrieve head from head writeback

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 6d4009e..cd7b52f 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -10,14 +10,6 @@
 #include "i40e_txrx_common.h"
 #include "i40e_xsk.h"
 
-int i40e_alloc_rx_bi_zc(struct i40e_ring *rx_ring)
-{
-       unsigned long sz = sizeof(*rx_ring->rx_bi_zc) * rx_ring->count;
-
-       rx_ring->rx_bi_zc = kzalloc(sz, GFP_KERNEL);
-       return rx_ring->rx_bi_zc ? 0 : -ENOMEM;
-}
-
 void i40e_clear_rx_bi_zc(struct i40e_ring *rx_ring)
 {
        memset(rx_ring->rx_bi_zc, 0,
@@ -30,6 +22,58 @@ static struct xdp_buff **i40e_rx_bi(struct i40e_ring *rx_ring, u32 idx)
 }
 
 /**
+ * i40e_realloc_rx_xdp_bi - reallocate SW ring for either XSK or normal buffer
+ * @rx_ring: Current rx ring
+ * @pool_present: is pool for XSK present
+ *
+ * Try allocating memory and return ENOMEM, if failed to allocate.
+ * If allocation was successful, substitute buffer with allocated one.
+ * Returns 0 on success, negative on failure
+ */
+static int i40e_realloc_rx_xdp_bi(struct i40e_ring *rx_ring, bool pool_present)
+{
+       size_t elem_size = pool_present ? sizeof(*rx_ring->rx_bi_zc) :
+                                         sizeof(*rx_ring->rx_bi);
+       void *sw_ring = kcalloc(rx_ring->count, elem_size, GFP_KERNEL);
+
+       if (!sw_ring)
+               return -ENOMEM;
+
+       if (pool_present) {
+               kfree(rx_ring->rx_bi);
+               rx_ring->rx_bi = NULL;
+               rx_ring->rx_bi_zc = sw_ring;
+       } else {
+               kfree(rx_ring->rx_bi_zc);
+               rx_ring->rx_bi_zc = NULL;
+               rx_ring->rx_bi = sw_ring;
+       }
+       return 0;
+}
+
+/**
+ * i40e_realloc_rx_bi_zc - reallocate rx SW rings
+ * @vsi: Current VSI
+ * @zc: is zero copy set
+ *
+ * Reallocate buffer for rx_rings that might be used by XSK.
+ * XDP requires more memory, than rx_buf provides.
+ * Returns 0 on success, negative on failure
+ */
+int i40e_realloc_rx_bi_zc(struct i40e_vsi *vsi, bool zc)
+{
+       struct i40e_ring *rx_ring;
+       unsigned long q;
+
+       for_each_set_bit(q, vsi->af_xdp_zc_qps, vsi->alloc_queue_pairs) {
+               rx_ring = vsi->rx_rings[q];
+               if (i40e_realloc_rx_xdp_bi(rx_ring, zc))
+                       return -ENOMEM;
+       }
+       return 0;
+}
+
+/**
  * i40e_xsk_pool_enable - Enable/associate an AF_XDP buffer pool to a
  * certain ring/qid
  * @vsi: Current VSI
@@ -69,6 +113,10 @@ static int i40e_xsk_pool_enable(struct i40e_vsi *vsi,
                if (err)
                        return err;
 
+               err = i40e_realloc_rx_xdp_bi(vsi->rx_rings[qid], true);
+               if (err)
+                       return err;
+
                err = i40e_queue_pair_enable(vsi, qid);
                if (err)
                        return err;
@@ -113,6 +161,9 @@ static int i40e_xsk_pool_disable(struct i40e_vsi *vsi, u16 qid)
        xsk_pool_dma_unmap(pool, I40E_RX_DMA_ATTR);
 
        if (if_running) {
+               err = i40e_realloc_rx_xdp_bi(vsi->rx_rings[qid], false);
+               if (err)
+                       return err;
                err = i40e_queue_pair_enable(vsi, qid);
                if (err)
                        return err;

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.h b/drivers/net/ethernet/intel/i40e/i40e_xsk.h
index bb96298..821df24 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.h
@@ -32,7 +32,7 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget);
 
 bool i40e_clean_xdp_tx_irq(struct i40e_vsi *vsi, struct i40e_ring *tx_ring);
 int i40e_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags);
-int i40e_alloc_rx_bi_zc(struct i40e_ring *rx_ring);
+int i40e_realloc_rx_bi_zc(struct i40e_vsi *vsi, bool zc);
 void i40e_clear_rx_bi_zc(struct i40e_ring *rx_ring);
 
 #endif /* _I40E_XSK_H_ */