fix insta-panic:

- determine which ext_arg offsets to use based on the version number

Submitted by:	Chelsio Inc.
MFC after:	1 day

2 files changed, 9 insertions, 0 deletions

diff --git a/sys/dev/cxgb/sys/mvec.h b/sys/dev/cxgb/sys/mvec.h
index 09dbf129b270..855c03987587 100644
--- a/sys/dev/cxgb/sys/mvec.h
+++ b/sys/dev/cxgb/sys/mvec.h
@@ -62,8 +62,12 @@ struct m_ext_ {
 	caddr_t		 ext_buf;	/* start of buffer */
 	void		(*ext_free)	/* free routine if not the usual */
 			    (void *, void *);
+#if __FreeBSD_version >= 800016
 	void		*ext_arg1;	/* optional argument pointer */
 	void		*ext_arg2;	/* optional argument pointer */
+#else
+	void		*ext_args;	/* optional argument pointer */
+#endif
 	u_int		 ext_size;	/* size of buffer, for ext_free */
 	volatile u_int	*ref_cnt;	/* pointer to ref count info */
 	int		 ext_type;	/* type of external storage */
diff --git a/sys/dev/cxgb/sys/uipc_mvec.c b/sys/dev/cxgb/sys/uipc_mvec.c
index cf0de13f091e..1293e22b1e48 100644
--- a/sys/dev/cxgb/sys/uipc_mvec.c
+++ b/sys/dev/cxgb/sys/uipc_mvec.c
@@ -405,8 +405,13 @@ mb_free_ext_fast(struct mbuf_iovec *mi, int type, int idx)
 	case EXT_EXTREF:
 		KASSERT(mi->mi_ext.ext_free != NULL,
 		    ("%s: ext_free not set", __func__));
+#if __FreeBSD_version >= 800016
 		(*(mi->mi_ext.ext_free))(mi->mi_ext.ext_arg1,
 		    mi->mi_ext.ext_arg2);
+#else
+		(*(mi->mi_ext.ext_free))(mi->mi_ext.ext_buf,
+		    mi->mi_ext.ext_args);
+#endif
 		break;
 	default:
 		dump_mi(mi);