diff --git a/src/cmd/internal/objabi/reloctype.go b/src/cmd/internal/objabi/reloctype.go
index f619e017d8..94d5469d9c 100644
--- a/src/cmd/internal/objabi/reloctype.go
+++ b/src/cmd/internal/objabi/reloctype.go
@@ -30,7 +30,7 @@
 
 package objabi
 
-type RelocType int32
+type RelocType int16
 
 //go:generate stringer -type=RelocType
 const (
diff --git a/src/cmd/link/internal/ld/data.go b/src/cmd/link/internal/ld/data.go
index 3b551db853..8e35f5c9dc 100644
--- a/src/cmd/link/internal/ld/data.go
+++ b/src/cmd/link/internal/ld/data.go
@@ -189,13 +189,19 @@ func relocsym(ctxt *Link, s *sym.Symbol) {
 			Errorf(s, "unreachable sym in relocation: %s", r.Sym.Name)
 		}
 
+		if ctxt.LinkMode == LinkExternal {
+			r.InitExt()
+		}
+
 		// TODO(mundaym): remove this special case - see issue 14218.
 		if ctxt.Arch.Family == sys.S390X {
 			switch r.Type {
 			case objabi.R_PCRELDBL:
+				r.InitExt()
 				r.Type = objabi.R_PCREL
 				r.Variant = sym.RV_390_DBL
 			case objabi.R_CALL:
+				r.InitExt()
 				r.Variant = sym.RV_390_DBL
 			}
 		}
@@ -499,8 +505,11 @@ func relocsym(ctxt *Link, s *sym.Symbol) {
 			o = r.Add
 		}
 
-		if r.Variant != sym.RV_NONE {
-			o = thearch.Archrelocvariant(ctxt, r, s, o)
+		if ctxt.Arch.Family == sys.PPC64 || ctxt.Arch.Family == sys.S390X {
+			r.InitExt()
+			if r.Variant != sym.RV_NONE {
+				o = thearch.Archrelocvariant(ctxt, r, s, o)
+			}
 		}
 
 		if false {
diff --git a/src/cmd/link/internal/ppc64/asm.go b/src/cmd/link/internal/ppc64/asm.go
index 365a45ec13..c315b4bfc2 100644
--- a/src/cmd/link/internal/ppc64/asm.go
+++ b/src/cmd/link/internal/ppc64/asm.go
@@ -272,6 +272,7 @@ func adddynrel(ctxt *ld.Link, s *sym.Symbol, r *sym.Reloc) bool {
 }
 func addelfdynrel(ctxt *ld.Link, s *sym.Symbol, r *sym.Reloc) bool {
 	targ := r.Sym
+	r.InitExt()
 
 	switch r.Type {
 	default:
diff --git a/src/cmd/link/internal/s390x/asm.go b/src/cmd/link/internal/s390x/asm.go
index 8540377400..040c573705 100644
--- a/src/cmd/link/internal/s390x/asm.go
+++ b/src/cmd/link/internal/s390x/asm.go
@@ -104,6 +104,7 @@ func gentext(ctxt *ld.Link) {
 
 func adddynrel(ctxt *ld.Link, s *sym.Symbol, r *sym.Reloc) bool {
 	targ := r.Sym
+	r.InitExt()
 
 	switch r.Type {
 	default:
diff --git a/src/cmd/link/internal/sym/reloc.go b/src/cmd/link/internal/sym/reloc.go
index 9c862f109d..4809db8c80 100644
--- a/src/cmd/link/internal/sym/reloc.go
+++ b/src/cmd/link/internal/sym/reloc.go
@@ -22,15 +22,27 @@ import (
 //
 // Some relocations are created by cmd/link.
 type Reloc struct {
-	Off     int32            // offset to rewrite
-	Siz     uint8            // number of bytes to rewrite, 1, 2, or 4
-	Done    bool             // set to true when relocation is complete
-	Variant RelocVariant     // variation on Type
-	Type    objabi.RelocType // the relocation type
-	Add     int64            // addend
-	Xadd    int64            // addend passed to external linker
-	Sym     *Symbol          // symbol the relocation addresses
-	Xsym    *Symbol          // symbol passed to external linker
+	Off       int32            // offset to rewrite
+	Siz       uint8            // number of bytes to rewrite, 1, 2, or 4
+	Done      bool             // set to true when relocation is complete
+	Type      objabi.RelocType // the relocation type
+	Add       int64            // addend
+	Sym       *Symbol          // symbol the relocation addresses
+	*relocExt                  // extra fields (see below), may be nil, call InitExt before use
+}
+
+// relocExt contains extra fields in Reloc that are used only in
+// certain cases.
+type relocExt struct {
+	Xadd    int64        // addend passed to external linker
+	Xsym    *Symbol      // symbol passed to external linker
+	Variant RelocVariant // variation on Type, currently used only on PPC64 and S390X
+}
+
+func (r *Reloc) InitExt() {
+	if r.relocExt == nil {
+		r.relocExt = new(relocExt)
+	}
 }
 
 // RelocVariant is a linker-internal variation on a relocation.
diff --git a/src/cmd/link/internal/sym/symbol.go b/src/cmd/link/internal/sym/symbol.go
index 88a28f5b99..d115a3326f 100644
--- a/src/cmd/link/internal/sym/symbol.go
+++ b/src/cmd/link/internal/sym/symbol.go
@@ -211,6 +211,9 @@ func (s *Symbol) AddPCRelPlus(arch *sys.Arch, t *Symbol, add int64) int64 {
 	r.Add = add
 	r.Type = objabi.R_PCREL
 	r.Siz = 4
+	if arch.Family == sys.S390X || arch.Family == sys.PPC64 {
+		r.InitExt()
+	}
 	if arch.Family == sys.S390X {
 		r.Variant = RV_390_DBL
 	}