Index: sys/sys/sbuf.h
===================================================================
--- sys/sys/sbuf.h	(revision 268937)
+++ sys/sys/sbuf.h	(working copy)
@@ -33,6 +33,8 @@
 
 #include <sys/_types.h>
 
+.symver _sbuf_setpos_old, sbuf_setpos@FBSD_1.3
+
 struct sbuf;
 typedef int (sbuf_drain_func)(void *, const char *, int);
 
Index: lib/libsbuf/Version.def
===================================================================
--- lib/libsbuf/Version.def	(revision 268937)
+++ lib/libsbuf/Version.def	(working copy)
@@ -5,3 +5,6 @@
 
 FBSD_1.3 {
 } FBSD_1.2;
+
+FBSD_1.4 {
+} FBSD_1.3;
Index: sys/kern/subr_sbuf.c
===================================================================
--- sys/kern/subr_sbuf.c	(revision 268937)
+++ sys/kern/subr_sbuf.c	(working copy)
@@ -289,6 +289,19 @@
 }
 
 /*
+ * Compat shim for buf_setpos with pos being ssize_t.
+ */
+int _sbuf_setpos_old(struct sbuf *s, ssize_t pos)
+{
+	KASSERT(pos >= 0,
+	    ("attempt to seek to a negative position (%jd)", (intmax_t)pos));
+
+	if (pos < 0)
+		return (-1);
+	return (buf_setpos(s, pos));
+}
+
+/*
  * Set the sbuf's end position to an arbitrary value.
  * Effectively truncates the sbuf at the new position.
  */