From: Cherry Mui <cherryyz@google.com>
Date: Tue, 20 Feb 2024 20:05:29 +0000 (-0500)
Subject: cmd/compile: make jump table symbol static
X-Git-Tag: go1.23rc1~1179
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=290835298067014e906c540d64dcaa706d66b2ce;p=gostls13.git

cmd/compile: make jump table symbol static

The jump table symbol is accessed only from the function symbol
(in the same package), so it can be static. Also, if the function
is DUPOK and it is, somehow, compiled differently in two different
packages, the linker must choose the jump table symbol associated
to the function symbol it chose. Currently the jump table symbol
is DUPOK, so that is not guaranteed. Making it static will
guarantee that, as each copy of the function symbol refers to its
own jump table symbol.

For #65783.

Change-Id: I27e051d01ef585d07700b75d4dfac5768f16441e
Reviewed-on: https://go-review.googlesource.com/c/go/+/565535
Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@golang.org>
---

diff --git a/src/cmd/compile/internal/ssa/rewrite.go b/src/cmd/compile/internal/ssa/rewrite.go
index db21246446..d3ddfbfab2 100644
--- a/src/cmd/compile/internal/ssa/rewrite.go
+++ b/src/cmd/compile/internal/ssa/rewrite.go
@@ -2131,8 +2131,8 @@ func logicFlags32(x int32) flagConstant {
 
 func makeJumpTableSym(b *Block) *obj.LSym {
 	s := base.Ctxt.Lookup(fmt.Sprintf("%s.jump%d", b.Func.fe.Func().LSym.Name, b.ID))
-	s.Set(obj.AttrDuplicateOK, true)
-	s.Set(obj.AttrLocal, true)
+	// The jump table symbol is accessed only from the function symbol.
+	s.Set(obj.AttrStatic, true)
 	return s
 }