debug/elf: fix arm build
This change adds the minimum necessary to implement applyRelocations.
For adg, this code uses the switch statement.
Change-Id: I0989daab8d0e36c2a4f6a315ced258b832744616
Reviewed-on: https://go-review.googlesource.com/7266
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/src/debug/elf/file.go b/src/debug/elf/file.go
index b2174d4..7e0dcc5 100644
--- a/src/debug/elf/file.go
+++ b/src/debug/elf/file.go
@@ -524,20 +524,20 @@
// applyRelocations applies relocations to dst. rels is a relocations section
// in RELA format.
func (f *File) applyRelocations(dst []byte, rels []byte) error {
- if f.Class == ELFCLASS64 && f.Machine == EM_X86_64 {
+ switch {
+ case f.Class == ELFCLASS64 && f.Machine == EM_X86_64:
return f.applyRelocationsAMD64(dst, rels)
- }
- if f.Class == ELFCLASS32 && f.Machine == EM_386 {
+ case f.Class == ELFCLASS32 && f.Machine == EM_386:
return f.applyRelocations386(dst, rels)
- }
- if f.Class == ELFCLASS64 && f.Machine == EM_AARCH64 {
+ case f.Class == ELFCLASS32 && f.Machine == EM_ARM:
+ return f.applyRelocationsARM(dst, rels)
+ case f.Class == ELFCLASS64 && f.Machine == EM_AARCH64:
return f.applyRelocationsARM64(dst, rels)
- }
- if f.Class == ELFCLASS64 && f.Machine == EM_PPC64 {
+ case f.Class == ELFCLASS64 && f.Machine == EM_PPC64:
return f.applyRelocationsPPC64(dst, rels)
+ default:
+ return errors.New("applyRelocations: not implemented")
}
-
- return errors.New("not implemented")
}
func (f *File) applyRelocationsAMD64(dst []byte, rels []byte) error {
@@ -626,6 +626,44 @@
return nil
}
+func (f *File) applyRelocationsARM(dst []byte, rels []byte) error {
+ // 8 is the size of Rel32.
+ if len(rels)%8 != 0 {
+ return errors.New("length of relocation section is not a multiple of 8")
+ }
+
+ symbols, _, err := f.getSymbols(SHT_SYMTAB)
+ if err != nil {
+ return err
+ }
+
+ b := bytes.NewReader(rels)
+ var rel Rel32
+
+ for b.Len() > 0 {
+ binary.Read(b, f.ByteOrder, &rel)
+ symNo := rel.Info >> 8
+ t := R_ARM(rel.Info & 0xff)
+
+ if symNo == 0 || symNo > uint32(len(symbols)) {
+ continue
+ }
+ sym := &symbols[symNo-1]
+
+ switch t {
+ case R_ARM_REL32:
+ if rel.Off+4 >= uint32(len(dst)) {
+ continue
+ }
+ val := f.ByteOrder.Uint32(dst[rel.Off : rel.Off+4])
+ val += uint32(sym.Value)
+ f.ByteOrder.PutUint32(dst[rel.Off:rel.Off+4], val)
+ }
+ }
+
+ return nil
+}
+
func (f *File) applyRelocationsARM64(dst []byte, rels []byte) error {
// 24 is the size of Rela64.
if len(rels)%24 != 0 {
diff --git a/src/debug/elf/file_test.go b/src/debug/elf/file_test.go
index d57aaab..3e908bb 100644
--- a/src/debug/elf/file_test.go
+++ b/src/debug/elf/file_test.go
@@ -267,6 +267,12 @@
},
},
{
+ "testdata/go-relocation-test-gcc492-arm.obj",
+ []relocationTestEntry{
+ {0, &dwarf.Entry{Offset: 0xb, Tag: dwarf.TagCompileUnit, Children: true, Field: []dwarf.Field{{Attr: dwarf.AttrProducer, Val: "GNU C 4.9.2 20141224 (prerelease) -march=armv7-a -mfloat-abi=hard -mfpu=vfpv3-d16 -mtls-dialect=gnu -g"}, {Attr: dwarf.AttrLanguage, Val: int64(1)}, {Attr: dwarf.AttrName, Val: "go-relocation-test-gcc492.c"}, {Attr: dwarf.AttrCompDir, Val: "/root/go/src/debug/elf/testdata"}, {Attr: dwarf.AttrLowpc, Val: uint64(0x0)}, {Attr: dwarf.AttrHighpc, Val: int64(0x28)}, {Attr: dwarf.AttrStmtList, Val: int64(0)}}}},
+ },
+ },
+ {
"testdata/go-relocation-test-gcc482-ppc64le.obj",
[]relocationTestEntry{
{0, &dwarf.Entry{Offset: 0xb, Tag: dwarf.TagCompileUnit, Children: true, Field: []dwarf.Field{dwarf.Field{Attr: dwarf.AttrProducer, Val: "GNU C 4.8.2 -Asystem=linux -Asystem=unix -Asystem=posix -msecure-plt -mtune=power8 -mcpu=power7 -gdwarf-2 -fstack-protector"}, dwarf.Field{Attr: dwarf.AttrLanguage, Val: int64(1)}, dwarf.Field{Attr: dwarf.AttrName, Val: "go-relocation-test-gcc482-ppc64le.c"}, dwarf.Field{Attr: dwarf.AttrCompDir, Val: "/tmp"}, dwarf.Field{Attr: dwarf.AttrLowpc, Val: uint64(0x0)}, dwarf.Field{Attr: dwarf.AttrHighpc, Val: uint64(0x24)}, dwarf.Field{Attr: dwarf.AttrStmtList, Val: int64(0)}}}},
diff --git a/src/debug/elf/testdata/go-relocation-test-gcc492-arm.obj b/src/debug/elf/testdata/go-relocation-test-gcc492-arm.obj
new file mode 100644
index 0000000..ed45be2
--- /dev/null
+++ b/src/debug/elf/testdata/go-relocation-test-gcc492-arm.obj
Binary files differ
