From 9ba0948172cbb05308fb2a9db823a720f8ffb9ad Mon Sep 17 00:00:00 2001 From: Cherry Mui Date: Mon, 15 Dec 2025 13:45:28 -0500 Subject: [PATCH] cmd/link: don't create __x86.get_pc_thunk symbol if it already exists On 386, in some build modes we need to create the __x86.get_pc_thunk symbols, to support PC-relative addressing. In some situation the thunk symbols may already exist, e.g. loaded from a C object in internal linking mode. In this case, we should use the exiting symbol instead of making a new one. The current code updates the symbol content in place but also adds a duplicated entry to Textp, which breaks the address sorting order. Fixes #76815. Change-Id: Iab11106ce592dc5219b7a0e07cfafcd270661a2f Reviewed-on: https://go-review.googlesource.com/c/go/+/730161 Reviewed-by: David Chase LUCI-TryBot-Result: Go LUCI --- src/cmd/link/internal/x86/asm.go | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/cmd/link/internal/x86/asm.go b/src/cmd/link/internal/x86/asm.go index 036514819a0b06..2c38473702f646 100644 --- a/src/cmd/link/internal/x86/asm.go +++ b/src/cmd/link/internal/x86/asm.go @@ -72,6 +72,9 @@ func gentext(ctxt *ld.Link, ldr *loader.Loader) { {"di", 7}, } { thunkfunc := ldr.CreateSymForUpdate("__x86.get_pc_thunk."+r.name, 0) + if t := thunkfunc.Type(); t != 0 && t != sym.SXREF && t != sym.SDYNIMPORT && t != sym.SUNDEFEXT { + continue // symbol already exists, probably loaded from a C object + } thunkfunc.SetType(sym.STEXT) ldr.SetAttrLocal(thunkfunc.Sym(), true) o := func(op ...uint8) {