Revert "cmd/link: separate virtual address layout from file layout"

This reverts commit bd83774593.

Reason for revert: This broke ELF layout on arm, arm64, mips*, mips64*, ppc64*, and s390x.

Change-Id: I56a27b76e6f4b22ce39a99790af9116f8687eee9
Reviewed-on: https://go-review.googlesource.com/118675
Reviewed-by: Heschi Kreinick <heschi@google.com>
Run-TryBot: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/link/internal/ld/data.go

@@ -1903,15 +1903,12 @@ func assignAddress(ctxt *Link, sect *sym.Section, n int, s *sym.Symbol, va uint6
 	return sect, n, va
 }
 
-// address assigns virtual addresses to all segments and sections and
-// returns all segments in file order.
-func (ctxt *Link) address() []*sym.Segment {
-	var order []*sym.Segment // Layout order
-
+// assign addresses
+func (ctxt *Link) address() {
 	va := uint64(*FlagTextAddr)
-	order = append(order, &Segtext)
 	Segtext.Rwx = 05
 	Segtext.Vaddr = va
+	Segtext.Fileoff = uint64(HEADR)
 	for _, s := range Segtext.Sections {
 		va = uint64(Rnd(int64(va), int64(s.Align)))
 		s.Vaddr = va
@@ -1919,6 +1916,7 @@ func (ctxt *Link) address() []*sym.Segment {
 	}
 
 	Segtext.Length = va - uint64(*FlagTextAddr)
+	Segtext.Filelen = Segtext.Length
 	if ctxt.HeadType == objabi.Hnacl {
 		va += 32 // room for the "halt sled"
 	}
@@ -1939,9 +1937,13 @@ func (ctxt *Link) address() []*sym.Segment {
 		// writable even for this short period.
 		va = uint64(Rnd(int64(va), int64(*FlagRound)))
 
-		order = append(order, &Segrodata)
 		Segrodata.Rwx = 04
 		Segrodata.Vaddr = va
+		Segrodata.Fileoff = va - Segtext.Vaddr + Segtext.Fileoff
+		Segrodata.Filelen = 0
+		if ctxt.HeadType == objabi.Hwindows {
+			Segrodata.Fileoff = Segtext.Fileoff + uint64(Rnd(int64(Segtext.Length), PEFILEALIGN))
+		}
 		for _, s := range Segrodata.Sections {
 			va = uint64(Rnd(int64(va), int64(s.Align)))
 			s.Vaddr = va
@@ -1949,15 +1951,17 @@ func (ctxt *Link) address() []*sym.Segment {
 		}
 
 		Segrodata.Length = va - Segrodata.Vaddr
+		Segrodata.Filelen = Segrodata.Length
 	}
 	if len(Segrelrodata.Sections) > 0 {
 		// align to page boundary so as not to mix
 		// rodata, rel-ro data, and executable text.
 		va = uint64(Rnd(int64(va), int64(*FlagRound)))
 
-		order = append(order, &Segrelrodata)
 		Segrelrodata.Rwx = 06
 		Segrelrodata.Vaddr = va
+		Segrelrodata.Fileoff = va - Segrodata.Vaddr + Segrodata.Fileoff
+		Segrelrodata.Filelen = 0
 		for _, s := range Segrelrodata.Sections {
 			va = uint64(Rnd(int64(va), int64(s.Align)))
 			s.Vaddr = va
@@ -1965,12 +1969,20 @@ func (ctxt *Link) address() []*sym.Segment {
 		}
 
 		Segrelrodata.Length = va - Segrelrodata.Vaddr
+		Segrelrodata.Filelen = Segrelrodata.Length
 	}
 
 	va = uint64(Rnd(int64(va), int64(*FlagRound)))
-	order = append(order, &Segdata)
 	Segdata.Rwx = 06
 	Segdata.Vaddr = va
+	Segdata.Fileoff = va - Segtext.Vaddr + Segtext.Fileoff
+	Segdata.Filelen = 0
+	if ctxt.HeadType == objabi.Hwindows {
+		Segdata.Fileoff = Segrodata.Fileoff + uint64(Rnd(int64(Segrodata.Length), PEFILEALIGN))
+	}
+	if ctxt.HeadType == objabi.Hplan9 {
+		Segdata.Fileoff = Segtext.Fileoff + Segtext.Filelen
+	}
 	var data *sym.Section
 	var noptr *sym.Section
 	var bss *sym.Section
@@ -2000,14 +2012,16 @@ func (ctxt *Link) address() []*sym.Segment {
 		}
 	}
 
-	// Assign Segdata's Filelen omitting the BSS. We do this here
-	// simply because right now we know where the BSS starts.
 	Segdata.Filelen = bss.Vaddr - Segdata.Vaddr
 
 	va = uint64(Rnd(int64(va), int64(*FlagRound)))
-	order = append(order, &Segdwarf)
 	Segdwarf.Rwx = 06
 	Segdwarf.Vaddr = va
+	Segdwarf.Fileoff = Segdata.Fileoff + uint64(Rnd(int64(Segdata.Filelen), int64(*FlagRound)))
+	Segdwarf.Filelen = 0
+	if ctxt.HeadType == objabi.Hwindows {
+		Segdwarf.Fileoff = Segdata.Fileoff + uint64(Rnd(int64(Segdata.Filelen), PEFILEALIGN))
+	}
 	for i, s := range Segdwarf.Sections {
 		vlen := int64(s.Length)
 		if i+1 < len(Segdwarf.Sections) {
@@ -2021,6 +2035,8 @@ func (ctxt *Link) address() []*sym.Segment {
 		Segdwarf.Length = va - Segdwarf.Vaddr
 	}
 
+	Segdwarf.Filelen = va - Segdwarf.Vaddr
+
 	var (
 		text     = Segtext.Sections[0]
 		rodata   = ctxt.Syms.Lookup("runtime.rodata", 0).Sect
@@ -2107,34 +2123,6 @@ func (ctxt *Link) address() []*sym.Segment {
 	ctxt.xdefine("runtime.noptrbss", sym.SNOPTRBSS, int64(noptrbss.Vaddr))
 	ctxt.xdefine("runtime.enoptrbss", sym.SNOPTRBSS, int64(noptrbss.Vaddr+noptrbss.Length))
 	ctxt.xdefine("runtime.end", sym.SBSS, int64(Segdata.Vaddr+Segdata.Length))
-
-	return order
-}
-
-// layout assigns file offsets and lengths to the segments in order.
-func (ctxt *Link) layout(order []*sym.Segment) {
-	var prev *sym.Segment
-	for _, seg := range order {
-		if prev == nil {
-			seg.Fileoff = uint64(HEADR)
-		} else {
-			switch ctxt.HeadType {
-			default:
-				seg.Fileoff = prev.Fileoff + uint64(Rnd(int64(prev.Filelen), int64(*FlagRound)))
-			case objabi.Hwindows:
-				seg.Fileoff = prev.Fileoff + uint64(Rnd(int64(prev.Filelen), PEFILEALIGN))
-			case objabi.Hplan9:
-				seg.Fileoff = prev.Fileoff + prev.Filelen
-			}
-		}
-		if seg != &Segdata {
-			// Link.address already set Segdata.Filelen to
-			// account for BSS.
-			seg.Filelen = seg.Length
-		}
-		prev = seg
-	}
-
 }
 
 // add a trampoline with symbol s (to be laid down after the current function)

src/cmd/link/internal/ld/main.go

@@ -224,9 +224,8 @@ func Main(arch *sys.Arch, theArch Arch) {
 	ctxt.typelink()
 	ctxt.symtab()
 	ctxt.dodata()
-	order := ctxt.address()
+	ctxt.address()
 	ctxt.reloc()
-	ctxt.layout(order)
 	thearch.Asmb(ctxt)
 	ctxt.undef()
 	ctxt.hostlink()