svn commit: r363163 - stable/12/sys/net

[Alexander Motin]

Author: mav
Date: Mon Jul 13 17:20:20 2020
New Revision: 363163
URL: https://svnweb.freebsd.org/changeset/base/363163

Log:
  MFC r358995 (by pkelsey): Fix iflib freelist state corruption
  
  This fixes a bug in iflib freelist management that breaks the required
  correspondence between freelist indexes and driver ring slots.
  
  PR: 243126, 243392, 240628

Modified:
  stable/12/sys/net/iflib.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/net/iflib.c
==============================================================================
--- stable/12/sys/net/iflib.c	Mon Jul 13 17:05:44 2020	(r363162)
+++ stable/12/sys/net/iflib.c	Mon Jul 13 17:20:20 2020	(r363163)
@@ -2122,7 +2122,9 @@ _iflib_fl_refill(if_ctx_t ctx, iflib_fl_t fl, int coun
 	bus_dmamap_sync(fl->ifl_ifdi->idi_tag, fl->ifl_ifdi->idi_map,
 	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 	ctx->isc_rxd_flush(ctx->ifc_softc, fl->ifl_rxq->ifr_id, fl->ifl_id, pidx);
-	fl->ifl_fragidx = frag_idx;
+	fl->ifl_fragidx = frag_idx + 1;
+	if (fl->ifl_fragidx == fl->ifl_size)
+		fl->ifl_fragidx = 0;
 
 	return (n == -1 ? 0 : IFLIB_RXEOF_EMPTY);
 }