cmd/link: put DYLD_INFO at beginning of LINKEDIT segment on darwin

Apparently, code signing requires DYLD_INFO tables are at the
beginning of the LINKEDIT segment. Put it there.

May fix #42507.

Change-Id: I1836e0f495719cf75f66d0831fe1544bbe3ff1a8
Reviewed-on: https://go-review.googlesource.com/c/go/+/269377
Trust: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>

diff --git a/src/cmd/link/internal/ld/macho.go b/src/cmd/link/internal/ld/macho.go
index 155769c48ffb508b35b6f230c388e891b415b147..51abefc8875dba9d59f4caa4119ed99a85b25cda 100644 (file)
--- a/src/cmd/link/internal/ld/macho.go
+++ b/src/cmd/link/internal/ld/macho.go
@@ -761,12 +761,12 @@ func asmbMacho(ctxt *Link) {
                ldr := ctxt.loader
 
                // must match domacholink below
-               s1 := ldr.SymSize(ldr.Lookup(".machosymtab", 0))
-               s2 := ldr.SymSize(ctxt.ArchSyms.LinkEditPLT)
-               s3 := ldr.SymSize(ctxt.ArchSyms.LinkEditGOT)
-               s4 := ldr.SymSize(ldr.Lookup(".machosymstr", 0))
-               s5 := ldr.SymSize(ldr.Lookup(".machorebase", 0))
-               s6 := ldr.SymSize(ldr.Lookup(".machobind", 0))
+               s1 := ldr.SymSize(ldr.Lookup(".machorebase", 0))
+               s2 := ldr.SymSize(ldr.Lookup(".machobind", 0))
+               s3 := ldr.SymSize(ldr.Lookup(".machosymtab", 0))
+               s4 := ldr.SymSize(ctxt.ArchSyms.LinkEditPLT)
+               s5 := ldr.SymSize(ctxt.ArchSyms.LinkEditGOT)
+               s6 := ldr.SymSize(ldr.Lookup(".machosymstr", 0))
 
                if ctxt.LinkMode != LinkExternal {
                        ms := newMachoSeg("__LINKEDIT", 0)
@@ -778,13 +778,27 @@ func asmbMacho(ctxt *Link) {
                        ms.prot2 = 1
                }
 
+               if ctxt.LinkMode != LinkExternal && ctxt.IsPIE() {
+                       ml := newMachoLoad(ctxt.Arch, LC_DYLD_INFO_ONLY, 10)
+                       ml.data[0] = uint32(linkoff)      // rebase off
+                       ml.data[1] = uint32(s1)           // rebase size
+                       ml.data[2] = uint32(linkoff + s1) // bind off
+                       ml.data[3] = uint32(s2)           // bind size
+                       ml.data[4] = 0                    // weak bind off
+                       ml.data[5] = 0                    // weak bind size
+                       ml.data[6] = 0                    // lazy bind off
+                       ml.data[7] = 0                    // lazy bind size
+                       ml.data[8] = 0                    // export
+                       ml.data[9] = 0                    // export size
+               }
+
                ml := newMachoLoad(ctxt.Arch, LC_SYMTAB, 4)
-               ml.data[0] = uint32(linkoff)                /* symoff */
-               ml.data[1] = uint32(nsortsym)               /* nsyms */
-               ml.data[2] = uint32(linkoff + s1 + s2 + s3) /* stroff */
-               ml.data[3] = uint32(s4)                     /* strsize */
+               ml.data[0] = uint32(linkoff + s1 + s2)                /* symoff */
+               ml.data[1] = uint32(nsortsym)                         /* nsyms */
+               ml.data[2] = uint32(linkoff + s1 + s2 + s3 + s4 + s5) /* stroff */
+               ml.data[3] = uint32(s6)                               /* strsize */
 
-               machodysymtab(ctxt)
+               machodysymtab(ctxt, linkoff+s1+s2)
 
                if ctxt.LinkMode != LinkExternal {
                        ml := newMachoLoad(ctxt.Arch, LC_LOAD_DYLINKER, 6)
@@ -800,20 +814,6 @@ func asmbMacho(ctxt *Link) {
                                stringtouint32(ml.data[4:], lib)
                        }
                }
-
-               if ctxt.LinkMode != LinkExternal && ctxt.IsPIE() {
-                       ml := newMachoLoad(ctxt.Arch, LC_DYLD_INFO_ONLY, 10)
-                       ml.data[0] = uint32(linkoff + s1 + s2 + s3 + s4)      // rebase off
-                       ml.data[1] = uint32(s5)                               // rebase size
-                       ml.data[2] = uint32(linkoff + s1 + s2 + s3 + s4 + s5) // bind off
-                       ml.data[3] = uint32(s6)                               // bind size
-                       ml.data[4] = 0                                        // weak bind off
-                       ml.data[5] = 0                                        // weak bind size
-                       ml.data[6] = 0                                        // lazy bind off
-                       ml.data[7] = 0                                        // lazy bind size
-                       ml.data[8] = 0                                        // export
-                       ml.data[9] = 0                                        // export size
-               }
        }
 
        a := machowrite(ctxt, ctxt.Arch, ctxt.Out, ctxt.LinkMode)
@@ -1018,7 +1018,7 @@ func machosymtab(ctxt *Link) {
        }
 }
 
-func machodysymtab(ctxt *Link) {
+func machodysymtab(ctxt *Link, base int64) {
        ml := newMachoLoad(ctxt.Arch, LC_DYSYMTAB, 18)
 
        n := 0
@@ -1046,7 +1046,7 @@ func machodysymtab(ctxt *Link) {
        s1 := ldr.SymSize(ldr.Lookup(".machosymtab", 0))
        s2 := ldr.SymSize(ctxt.ArchSyms.LinkEditPLT)
        s3 := ldr.SymSize(ctxt.ArchSyms.LinkEditGOT)
-       ml.data[12] = uint32(linkoff + s1)  /* indirectsymoff */
+       ml.data[12] = uint32(base + s1)     /* indirectsymoff */
        ml.data[13] = uint32((s2 + s3) / 4) /* nindirectsyms */
 
        ml.data[14] = 0 /* extreloff */
@@ -1063,12 +1063,12 @@ func doMachoLink(ctxt *Link) int64 {
        ldr := ctxt.loader
 
        // write data that will be linkedit section
-       s1 := ldr.Lookup(".machosymtab", 0)
-       s2 := ctxt.ArchSyms.LinkEditPLT
-       s3 := ctxt.ArchSyms.LinkEditGOT
-       s4 := ldr.Lookup(".machosymstr", 0)
-       s5 := ldr.Lookup(".machorebase", 0)
-       s6 := ldr.Lookup(".machobind", 0)
+       s1 := ldr.Lookup(".machorebase", 0)
+       s2 := ldr.Lookup(".machobind", 0)
+       s3 := ldr.Lookup(".machosymtab", 0)
+       s4 := ctxt.ArchSyms.LinkEditPLT
+       s5 := ctxt.ArchSyms.LinkEditGOT
+       s6 := ldr.Lookup(".machosymstr", 0)
 
        // Force the linkedit section to end on a 16-byte
        // boundary. This allows pure (non-cgo) Go binaries
@@ -1087,9 +1087,9 @@ func doMachoLink(ctxt *Link) int64 {
        // boundary, codesign_allocate will not need to apply
        // any alignment padding itself, working around the
        // issue.
-       s4b := ldr.MakeSymbolUpdater(s4)
-       for s4b.Size()%16 != 0 {
-               s4b.AddUint8(0)
+       s6b := ldr.MakeSymbolUpdater(s6)
+       for s6b.Size()%16 != 0 {
+               s6b.AddUint8(0)
        }
 
        size := int(ldr.SymSize(s1) + ldr.SymSize(s2) + ldr.SymSize(s3) + ldr.SymSize(s4) + ldr.SymSize(s5) + ldr.SymSize(s6))