From c091767d87b7a6ef6016286bc0fae8add59b92de Mon Sep 17 00:00:00 2001 From: Keith Randall Date: Fri, 15 Oct 2021 13:52:05 -0700 Subject: [PATCH] cmd/asm: report an error when trying to do spectre on 386 The compiler refuses to do spectre mitigation on 386, but the assembler doesn't. Fix that. Fixes #49006 Change-Id: I887b6f7ed7523a47f463706f06ca4c2c6e828b6b Reviewed-on: https://go-review.googlesource.com/c/go/+/356190 Trust: Keith Randall Run-TryBot: Keith Randall TryBot-Result: Go Bot Reviewed-by: Bryan C. Mills --- src/cmd/internal/obj/x86/asm6.go | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/cmd/internal/obj/x86/asm6.go b/src/cmd/internal/obj/x86/asm6.go index 43ce832b17..6555756fd3 100644 --- a/src/cmd/internal/obj/x86/asm6.go +++ b/src/cmd/internal/obj/x86/asm6.go @@ -2035,6 +2035,11 @@ type nopPad struct { } func span6(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) { + if ctxt.Retpoline && ctxt.Arch.Family == sys.I386 { + ctxt.Diag("-spectre=ret not supported on 386") + ctxt.Retpoline = false // don't keep printing + } + pjc := makePjcCtx(ctxt) if s.P != nil { -- 2.50.0