Patch "ice: xsk: return xsk buffers back to pool when cleaning the ring" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ice: xsk: return xsk buffers back to pool when cleaning the ring

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ice-xsk-return-xsk-buffers-back-to-pool-when-cleanin.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit e74f2c667a2e6ccd61b8f7c46ba4b4141746d22f
Author: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
Date:   Mon Dec 13 16:31:06 2021 +0100

    ice: xsk: return xsk buffers back to pool when cleaning the ring
    
    [ Upstream commit afe8a3ba85ec2a6b6849367e25c06a2f8e0ddd05 ]
    
    Currently we only NULL the xdp_buff pointer in the internal SW ring but
    we never give it back to the xsk buffer pool. This means that buffers
    can be leaked out of the buff pool and never be used again.
    
    Add missing xsk_buff_free() call to the routine that is supposed to
    clean the entries that are left in the ring so that these buffers in the
    umem can be used by other sockets.
    
    Also, only go through the space that is actually left to be cleaned
    instead of a whole ring.
    
    Fixes: 2d4238f55697 ("ice: Add support for AF_XDP")
    Signed-off-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
    Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
    Tested-by: Kiran Bhandare <kiranx.bhandare@xxxxxxxxx>
    Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
index f4ab5259a56cc..37c7dc6b44a9f 100644
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -810,14 +810,14 @@ bool ice_xsk_any_rx_ring_ena(struct ice_vsi *vsi)
  */
 void ice_xsk_clean_rx_ring(struct ice_ring *rx_ring)
 {
-	u16 i;
-
-	for (i = 0; i < rx_ring->count; i++) {
-		struct xdp_buff **xdp = &rx_ring->xdp_buf[i];
+	u16 count_mask = rx_ring->count - 1;
+	u16 ntc = rx_ring->next_to_clean;
+	u16 ntu = rx_ring->next_to_use;
 
-		if (!xdp)
-			continue;
+	for ( ; ntc != ntu; ntc = (ntc + 1) & count_mask) {
+		struct xdp_buff **xdp = &rx_ring->xdp_buf[ntc];
 
+		xsk_buff_free(*xdp);
 		*xdp = NULL;
 	}
 }