debug/elf: add s390x relocations

Change-Id: I8440f69c7f99d65b2f69035c26b4a62104f22bd3
Reviewed-on: https://go-review.googlesource.com/20874Reviewed-by: Minux Ma <minux@golang.org>

src/debug/elf/elf.go

@@ -1725,6 +1725,140 @@ var rppc64Strings = []intName{
 func (i R_PPC64) String() string   { return stringName(uint32(i), rppc64Strings, false) }
 func (i R_PPC64) GoString() string { return stringName(uint32(i), rppc64Strings, true) }
 
+// Relocation types for s390x processors.
+type R_390 int
+
+const (
+	R_390_NONE        R_390 = 0
+	R_390_8           R_390 = 1
+	R_390_12          R_390 = 2
+	R_390_16          R_390 = 3
+	R_390_32          R_390 = 4
+	R_390_PC32        R_390 = 5
+	R_390_GOT12       R_390 = 6
+	R_390_GOT32       R_390 = 7
+	R_390_PLT32       R_390 = 8
+	R_390_COPY        R_390 = 9
+	R_390_GLOB_DAT    R_390 = 10
+	R_390_JMP_SLOT    R_390 = 11
+	R_390_RELATIVE    R_390 = 12
+	R_390_GOTOFF      R_390 = 13
+	R_390_GOTPC       R_390 = 14
+	R_390_GOT16       R_390 = 15
+	R_390_PC16        R_390 = 16
+	R_390_PC16DBL     R_390 = 17
+	R_390_PLT16DBL    R_390 = 18
+	R_390_PC32DBL     R_390 = 19
+	R_390_PLT32DBL    R_390 = 20
+	R_390_GOTPCDBL    R_390 = 21
+	R_390_64          R_390 = 22
+	R_390_PC64        R_390 = 23
+	R_390_GOT64       R_390 = 24
+	R_390_PLT64       R_390 = 25
+	R_390_GOTENT      R_390 = 26
+	R_390_GOTOFF16    R_390 = 27
+	R_390_GOTOFF64    R_390 = 28
+	R_390_GOTPLT12    R_390 = 29
+	R_390_GOTPLT16    R_390 = 30
+	R_390_GOTPLT32    R_390 = 31
+	R_390_GOTPLT64    R_390 = 32
+	R_390_GOTPLTENT   R_390 = 33
+	R_390_GOTPLTOFF16 R_390 = 34
+	R_390_GOTPLTOFF32 R_390 = 35
+	R_390_GOTPLTOFF64 R_390 = 36
+	R_390_TLS_LOAD    R_390 = 37
+	R_390_TLS_GDCALL  R_390 = 38
+	R_390_TLS_LDCALL  R_390 = 39
+	R_390_TLS_GD32    R_390 = 40
+	R_390_TLS_GD64    R_390 = 41
+	R_390_TLS_GOTIE12 R_390 = 42
+	R_390_TLS_GOTIE32 R_390 = 43
+	R_390_TLS_GOTIE64 R_390 = 44
+	R_390_TLS_LDM32   R_390 = 45
+	R_390_TLS_LDM64   R_390 = 46
+	R_390_TLS_IE32    R_390 = 47
+	R_390_TLS_IE64    R_390 = 48
+	R_390_TLS_IEENT   R_390 = 49
+	R_390_TLS_LE32    R_390 = 50
+	R_390_TLS_LE64    R_390 = 51
+	R_390_TLS_LDO32   R_390 = 52
+	R_390_TLS_LDO64   R_390 = 53
+	R_390_TLS_DTPMOD  R_390 = 54
+	R_390_TLS_DTPOFF  R_390 = 55
+	R_390_TLS_TPOFF   R_390 = 56
+	R_390_20          R_390 = 57
+	R_390_GOT20       R_390 = 58
+	R_390_GOTPLT20    R_390 = 59
+	R_390_TLS_GOTIE20 R_390 = 60
+)
+
+var r390Strings = []intName{
+	{0, "R_390_NONE"},
+	{1, "R_390_8"},
+	{2, "R_390_12"},
+	{3, "R_390_16"},
+	{4, "R_390_32"},
+	{5, "R_390_PC32"},
+	{6, "R_390_GOT12"},
+	{7, "R_390_GOT32"},
+	{8, "R_390_PLT32"},
+	{9, "R_390_COPY"},
+	{10, "R_390_GLOB_DAT"},
+	{11, "R_390_JMP_SLOT"},
+	{12, "R_390_RELATIVE"},
+	{13, "R_390_GOTOFF"},
+	{14, "R_390_GOTPC"},
+	{15, "R_390_GOT16"},
+	{16, "R_390_PC16"},
+	{17, "R_390_PC16DBL"},
+	{18, "R_390_PLT16DBL"},
+	{19, "R_390_PC32DBL"},
+	{20, "R_390_PLT32DBL"},
+	{21, "R_390_GOTPCDBL"},
+	{22, "R_390_64"},
+	{23, "R_390_PC64"},
+	{24, "R_390_GOT64"},
+	{25, "R_390_PLT64"},
+	{26, "R_390_GOTENT"},
+	{27, "R_390_GOTOFF16"},
+	{28, "R_390_GOTOFF64"},
+	{29, "R_390_GOTPLT12"},
+	{30, "R_390_GOTPLT16"},
+	{31, "R_390_GOTPLT32"},
+	{32, "R_390_GOTPLT64"},
+	{33, "R_390_GOTPLTENT"},
+	{34, "R_390_GOTPLTOFF16"},
+	{35, "R_390_GOTPLTOFF32"},
+	{36, "R_390_GOTPLTOFF64"},
+	{37, "R_390_TLS_LOAD"},
+	{38, "R_390_TLS_GDCALL"},
+	{39, "R_390_TLS_LDCALL"},
+	{40, "R_390_TLS_GD32"},
+	{41, "R_390_TLS_GD64"},
+	{42, "R_390_TLS_GOTIE12"},
+	{43, "R_390_TLS_GOTIE32"},
+	{44, "R_390_TLS_GOTIE64"},
+	{45, "R_390_TLS_LDM32"},
+	{46, "R_390_TLS_LDM64"},
+	{47, "R_390_TLS_IE32"},
+	{48, "R_390_TLS_IE64"},
+	{49, "R_390_TLS_IEENT"},
+	{50, "R_390_TLS_LE32"},
+	{51, "R_390_TLS_LE64"},
+	{52, "R_390_TLS_LDO32"},
+	{53, "R_390_TLS_LDO64"},
+	{54, "R_390_TLS_DTPMOD"},
+	{55, "R_390_TLS_DTPOFF"},
+	{56, "R_390_TLS_TPOFF"},
+	{57, "R_390_20"},
+	{58, "R_390_GOT20"},
+	{59, "R_390_GOTPLT20"},
+	{60, "R_390_TLS_GOTIE20"},
+}
+
+func (i R_390) String() string   { return stringName(uint32(i), r390Strings, false) }
+func (i R_390) GoString() string { return stringName(uint32(i), r390Strings, true) }
+
 // Relocation types for SPARC.
 type R_SPARC int
 

src/debug/elf/file.go

@@ -596,6 +596,8 @@ func (f *File) applyRelocations(dst []byte, rels []byte) error {
 		return f.applyRelocationsPPC64(dst, rels)
 	case f.Class == ELFCLASS64 && f.Machine == EM_MIPS:
 		return f.applyRelocationsMIPS64(dst, rels)
+	case f.Class == ELFCLASS64 && f.Machine == EM_S390:
+		return f.applyRelocationss390x(dst, rels)
 	default:
 		return errors.New("applyRelocations: not implemented")
 	}
@@ -911,6 +913,55 @@ func (f *File) applyRelocationsMIPS64(dst []byte, rels []byte) error {
 	return nil
 }
 
+func (f *File) applyRelocationss390x(dst []byte, rels []byte) error {
+	// 24 is the size of Rela64.
+	if len(rels)%24 != 0 {
+		return errors.New("length of relocation section is not a multiple of 24")
+	}
+
+	symbols, _, err := f.getSymbols(SHT_SYMTAB)
+	if err != nil {
+		return err
+	}
+
+	b := bytes.NewReader(rels)
+	var rela Rela64
+
+	for b.Len() > 0 {
+		binary.Read(b, f.ByteOrder, &rela)
+		symNo := rela.Info >> 32
+		t := R_390(rela.Info & 0xffff)
+
+		if symNo == 0 || symNo > uint64(len(symbols)) {
+			continue
+		}
+		sym := &symbols[symNo-1]
+		switch SymType(sym.Info & 0xf) {
+		case STT_SECTION, STT_NOTYPE:
+			break
+		default:
+			continue
+		}
+
+		switch t {
+		case R_390_64:
+			if rela.Off+8 >= uint64(len(dst)) || rela.Addend < 0 {
+				continue
+			}
+			val := sym.Value + uint64(rela.Addend)
+			f.ByteOrder.PutUint64(dst[rela.Off:rela.Off+8], val)
+		case R_390_32:
+			if rela.Off+4 >= uint64(len(dst)) || rela.Addend < 0 {
+				continue
+			}
+			val := uint32(sym.Value) + uint32(rela.Addend)
+			f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4], val)
+		}
+	}
+
+	return nil
+}
+
 func (f *File) DWARF() (*dwarf.Data, error) {
 	// sectionData gets the data for s, checks its size, and
 	// applies any applicable relations.

src/debug/elf/file_test.go

@@ -472,6 +472,25 @@ var relocationTests = []relocationTest{
 			}},
 		},
 	},
+	{
+		"testdata/go-relocation-test-gcc531-s390x.obj",
+		[]relocationTestEntry{
+			{0, &dwarf.Entry{
+				Offset:   0xb,
+				Tag:      dwarf.TagCompileUnit,
+				Children: true,
+				Field: []dwarf.Field{
+					{Attr: dwarf.AttrProducer, Val: "GNU C11 5.3.1 20160316 -march=zEC12 -m64 -mzarch -g -fstack-protector-strong", Class: dwarf.ClassString},
+					{Attr: dwarf.AttrLanguage, Val: int64(12), Class: dwarf.ClassConstant},
+					{Attr: dwarf.AttrName, Val: "hello.c", Class: dwarf.ClassString},
+					{Attr: dwarf.AttrCompDir, Val: "/tmp", Class: dwarf.ClassString},
+					{Attr: dwarf.AttrLowpc, Val: uint64(0x0), Class: dwarf.ClassAddress},
+					{Attr: dwarf.AttrHighpc, Val: int64(58), Class: dwarf.ClassConstant},
+					{Attr: dwarf.AttrStmtList, Val: int64(0), Class: dwarf.ClassLinePtr},
+				},
+			}},
+		},
+	},
 	{
 		"testdata/go-relocation-test-gcc493-mips64le.obj",
 		[]relocationTestEntry{