svn commit: r299192 - in stable/10/sys/dev: e1000 ixgbe

[Sean Bruno]

Author: sbruno
Date: Fri May  6 19:14:57 2016
New Revision: 299192
URL: https://svnweb.freebsd.org/changeset/base/299192

Log:
  MFC r298224
  
  Correct possible underflow conditions when checking for available space
  in the tx h/w ring buffer.
  
  Sponsored by:	Limelight Networks

Modified:
  stable/10/sys/dev/e1000/if_em.c
  stable/10/sys/dev/e1000/if_igb.c
  stable/10/sys/dev/e1000/if_lem.c
  stable/10/sys/dev/ixgbe/ix_txrx.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/dev/e1000/if_em.c
==============================================================================
--- stable/10/sys/dev/e1000/if_em.c	Fri May  6 19:11:47 2016	(r299191)
+++ stable/10/sys/dev/e1000/if_em.c	Fri May  6 19:14:57 2016	(r299192)
@@ -2099,7 +2099,7 @@ retry:
 		txr->tx_tso = FALSE;
 	}
 
-        if (nsegs > (txr->tx_avail - EM_MAX_SCATTER)) {
+        if (txr->tx_avail < (nsegs + EM_MAX_SCATTER)) {
                 txr->no_desc_avail++;
 		bus_dmamap_unload(txr->txtag, map);
 		return (ENOBUFS);

Modified: stable/10/sys/dev/e1000/if_igb.c
==============================================================================
--- stable/10/sys/dev/e1000/if_igb.c	Fri May  6 19:11:47 2016	(r299191)
+++ stable/10/sys/dev/e1000/if_igb.c	Fri May  6 19:14:57 2016	(r299192)
@@ -1843,7 +1843,7 @@ retry:
 	}
 
 	/* Make certain there are enough descriptors */
-	if (nsegs > txr->tx_avail - 2) {
+	if (txr->tx_avail < (nsegs + 2)) {
 		txr->no_desc_avail++;
 		bus_dmamap_unload(txr->txtag, map);
 		return (ENOBUFS);

Modified: stable/10/sys/dev/e1000/if_lem.c
==============================================================================
--- stable/10/sys/dev/e1000/if_lem.c	Fri May  6 19:11:47 2016	(r299191)
+++ stable/10/sys/dev/e1000/if_lem.c	Fri May  6 19:14:57 2016	(r299192)
@@ -1694,7 +1694,7 @@ lem_xmit(struct adapter *adapter, struct
 		return (error);
 	}
 
-        if (nsegs > (adapter->num_tx_desc_avail - 2)) {
+        if (adapter->num_tx_desc_avail < (nsegs + 2)) {
                 adapter->no_tx_desc_avail2++;
 		bus_dmamap_unload(adapter->txtag, map);
 		return (ENOBUFS);

Modified: stable/10/sys/dev/ixgbe/ix_txrx.c
==============================================================================
--- stable/10/sys/dev/ixgbe/ix_txrx.c	Fri May  6 19:11:47 2016	(r299191)
+++ stable/10/sys/dev/ixgbe/ix_txrx.c	Fri May  6 19:14:57 2016	(r299192)
@@ -401,7 +401,7 @@ retry:
 	}
 
 	/* Make certain there are enough descriptors */
-	if (nsegs > txr->tx_avail - 2) {
+	if (txr->tx_avail < (nsegs + 2)) {
 		txr->no_desc_avail++;
 		bus_dmamap_unload(txr->txtag, map);
 		return (ENOBUFS);