ice: xsk: Fix cleaning of XDP_TX frames

Incrementation of xsk_frames inside the for-loop produces
infinite loop, if we have both normal AF_XDP-TX and XDP_TXed
buffers to complete.

Split xsk_frames into 2 variables (xsk_frames and completed_frames)
to eliminate this bug.

Fixes: 29322791bc8b ("ice: xsk: change batched Tx descriptor cleaning")
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Acked-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20230209160130.1779890-1-larysa.zaremba@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
index 7105de6fb3444bbfe7a1f5a269807a89f7896880..374b7f10b549be3fcad1ef4ddc01d6d9277ef607 100644 (file)
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -800,6 +800,7 @@ static void ice_clean_xdp_irq_zc(struct ice_tx_ring *xdp_ring)
        struct ice_tx_desc *tx_desc;
        u16 cnt = xdp_ring->count;
        struct ice_tx_buf *tx_buf;
+       u16 completed_frames = 0;
        u16 xsk_frames = 0;
        u16 last_rs;
        int i;
@@ -809,19 +810,21 @@ static void ice_clean_xdp_irq_zc(struct ice_tx_ring *xdp_ring)
        if ((tx_desc->cmd_type_offset_bsz &
            cpu_to_le64(ICE_TX_DESC_DTYPE_DESC_DONE))) {
                if (last_rs >= ntc)
-                       xsk_frames = last_rs - ntc + 1;
+                       completed_frames = last_rs - ntc + 1;
                else
-                       xsk_frames = last_rs + cnt - ntc + 1;
+                       completed_frames = last_rs + cnt - ntc + 1;
        }
 
-       if (!xsk_frames)
+       if (!completed_frames)
                return;
 
-       if (likely(!xdp_ring->xdp_tx_active))
+       if (likely(!xdp_ring->xdp_tx_active)) {
+               xsk_frames = completed_frames;
                goto skip;
+       }
 
        ntc = xdp_ring->next_to_clean;
-       for (i = 0; i < xsk_frames; i++) {
+       for (i = 0; i < completed_frames; i++) {
                tx_buf = &xdp_ring->tx_buf[ntc];
 
                if (tx_buf->raw_buf) {
@@ -837,7 +840,7 @@ static void ice_clean_xdp_irq_zc(struct ice_tx_ring *xdp_ring)
        }
 skip:
        tx_desc->cmd_type_offset_bsz = 0;
-       xdp_ring->next_to_clean += xsk_frames;
+       xdp_ring->next_to_clean += completed_frames;
        if (xdp_ring->next_to_clean >= cnt)
                xdp_ring->next_to_clean -= cnt;
        if (xsk_frames)