[dev.boringcrypto.go1.15] all: merge go1.15.11 into dev.boringcrypto.go1.15

Change-Id: I964039a36b7c2c6ef217717755ad78595a3b71fb

1 files changed, 11 insertions, 5 deletions

diff --git a/src/cmd/link/internal/arm/asm.go b/src/cmd/link/internal/arm/asm.go
index 903e62108e..43643341d2 100644
--- a/src/cmd/link/internal/arm/asm.go
+++ b/src/cmd/link/internal/arm/asm.go
@@ -373,10 +373,16 @@ func trampoline(ctxt *ld.Link, ldr *loader.Loader, ri int, rs, s loader.Sym) {
 	r := relocs.At2(ri)
 	switch r.Type() {
 	case objabi.R_CALLARM:
-		// r.Add is the instruction
-		// low 24-bit encodes the target address
-		t := (ldr.SymValue(rs) + int64(signext24(r.Add()&0xffffff)*4) - (ldr.SymValue(s) + int64(r.Off()))) / 4
-		if t > 0x7fffff || t < -0x800000 || (*ld.FlagDebugTramp > 1 && ldr.SymPkg(s) != ldr.SymPkg(rs)) {
+		var t int64
+		// ldr.SymValue(rs) == 0 indicates a cross-package jump to a function that is not yet
+		// laid out. Conservatively use a trampoline. This should be rare, as we lay out packages
+		// in dependency order.
+		if ldr.SymValue(rs) != 0 {
+			// r.Add is the instruction
+			// low 24-bit encodes the target address
+			t = (ldr.SymValue(rs) + int64(signext24(r.Add()&0xffffff)*4) - (ldr.SymValue(s) + int64(r.Off()))) / 4
+		}
+		if t > 0x7fffff || t < -0x800000 || ldr.SymValue(rs) == 0 || (*ld.FlagDebugTramp > 1 && ldr.SymPkg(s) != ldr.SymPkg(rs)) {
 			// direct call too far, need to insert trampoline.
 			// look up existing trampolines first. if we found one within the range
 			// of direct call, we can reuse it. otherwise create a new one.
@@ -447,7 +453,7 @@ func gentramp(arch *sys.Arch, linkmode ld.LinkMode, ldr *loader.Loader, tramp *l
 	arch.ByteOrder.PutUint32(P[8:], o3)
 	tramp.SetData(P)
 
-	if linkmode == ld.LinkExternal {
+	if linkmode == ld.LinkExternal || ldr.SymValue(target) == 0 {
 		r := loader.Reloc{
 			Off:  8,
 			Type: objabi.R_ADDR,