cmd/link: fix up more zero-sized local symbols on darwin dynamic linking

When dynamic linking on darwin, the darwin linker doesn't link
relocations pointing to zero-sized local symbols, like our
start/end marker symbols, e.g. runtime.text and runtime.etext.
It will choose to resolve to another symbol on the same address
that may not be local, therefore that reference may point to a
different DSO, which is not what we want. We already fix up some
marker symbols, like text/etext, data/edata, bss/ebss. But we
currently don't fix up noptrdata and noptrbss. With the new
darwin linker ld-prime, this causes problems when building a
plugin. Fix up those symbols.

For #61229.

Change-Id: I2181bb9184b85af9a3c3f5dc6d78e4d5a1d56d53
Reviewed-on: https://go-review.googlesource.com/c/go/+/503538
Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/src/cmd/link/internal/ld/data.go b/src/cmd/link/internal/ld/data.go
index 95fc8b5a42ac822334579d786a93183f323342d9..a9f10af5afc4b57a9e31c053067394015d4b8489 100644 (file)
--- a/src/cmd/link/internal/ld/data.go
+++ b/src/cmd/link/internal/ld/data.go
@@ -1075,7 +1075,7 @@ func writeBlock(ctxt *Link, out *OutBuf, ldr *loader.Loader, syms []loader.Sym,
                        break
                }
                if val < addr {
-                       ldr.Errorf(s, "phase error: addr=%#x but sym=%#x type=%v sect=%v", addr, val, ldr.SymType(s), ldr.SymSect(s).Name)
+                       ldr.Errorf(s, "phase error: addr=%#x but val=%#x sym=%s type=%v sect=%v sect.addr=%#x", addr, val, ldr.SymName(s), ldr.SymType(s), ldr.SymSect(s).Name, ldr.SymSect(s).Vaddr)
                        errorexit()
                }
                if addr < val {
@@ -1426,6 +1426,20 @@ func fixZeroSizedSymbols(ctxt *Link) {
                edata.SetType(sym.SXCOFFTOC)
        }
 
+       noptrbss := ldr.CreateSymForUpdate("runtime.noptrbss", 0)
+       noptrbss.SetSize(8)
+       ldr.SetAttrSpecial(noptrbss.Sym(), false)
+
+       enoptrbss := ldr.CreateSymForUpdate("runtime.enoptrbss", 0)
+       ldr.SetAttrSpecial(enoptrbss.Sym(), false)
+
+       noptrdata := ldr.CreateSymForUpdate("runtime.noptrdata", 0)
+       noptrdata.SetSize(8)
+       ldr.SetAttrSpecial(noptrdata.Sym(), false)
+
+       enoptrdata := ldr.CreateSymForUpdate("runtime.enoptrdata", 0)
+       ldr.SetAttrSpecial(enoptrdata.Sym(), false)
+
        types := ldr.CreateSymForUpdate("runtime.types", 0)
        types.SetType(sym.STYPE)
        types.SetSize(8)
@@ -2234,10 +2248,12 @@ func (state *dodataState) dodataSect(ctxt *Link, symn sym.SymKind, syms []loader
                // end of their section.
                if (ctxt.DynlinkingGo() && ctxt.HeadType == objabi.Hdarwin) || (ctxt.HeadType == objabi.Haix && ctxt.LinkMode == LinkExternal) {
                        switch ldr.SymName(s) {
-                       case "runtime.text", "runtime.bss", "runtime.data", "runtime.types", "runtime.rodata":
+                       case "runtime.text", "runtime.bss", "runtime.data", "runtime.types", "runtime.rodata",
+                               "runtime.noptrdata", "runtime.noptrbss":
                                head = s
                                continue
-                       case "runtime.etext", "runtime.ebss", "runtime.edata", "runtime.etypes", "runtime.erodata":
+                       case "runtime.etext", "runtime.ebss", "runtime.edata", "runtime.etypes", "runtime.erodata",
+                               "runtime.enoptrdata", "runtime.enoptrbss":
                                tail = s
                                continue
                        }