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 <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
diff --git a/src/cmd/internal/obj/x86/asm6.go b/src/cmd/internal/obj/x86/asm6.go
index 43ce832..6555756 100644
--- a/src/cmd/internal/obj/x86/asm6.go
+++ b/src/cmd/internal/obj/x86/asm6.go
@@ -2035,6 +2035,11 @@
}
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 {
