PR 65417 points out that the gccgo debug/elf package does not support
PPC32 relocations, which means that the cgo tool does not work
correctly. This patch fixes that. This is a backport of
http://golang.org/cl/7590 from the master library sources.
Bootstrapped and ran Go testsuite on x86_64-unknown-linux-gnu.
Committed to mainline.
Ian
diff -r 6ed23fc8eac4 libgo/go/debug/elf/file.go
--- a/libgo/go/debug/elf/file.go Tue Mar 24 12:43:53 2015 -0700
+++ b/libgo/go/debug/elf/file.go Tue Mar 24 13:51:18 2015 -0700
@@ -532,6 +532,9 @@
if f.Class == ELFCLASS64 && f.Machine == EM_AARCH64 {
return f.applyRelocationsARM64(dst, rels)
}
+ if f.Class == ELFCLASS32 && f.Machine == EM_PPC {
+ return f.applyRelocationsPPC(dst, rels)
+ }
if f.Class == ELFCLASS64 && f.Machine == EM_PPC64 {
return f.applyRelocationsPPC64(dst, rels)
}
@@ -677,6 +680,46 @@
return nil
}
+func (f *File) applyRelocationsPPC(dst []byte, rels []byte) error {
+ // 12 is the size of Rela32.
+ if len(rels)%12 != 0 {
+ return errors.New("length of relocation section is not a
multiple of 12")
+ }
+
+ symbols, _, err := f.getSymbols(SHT_SYMTAB)
+ if err != nil {
+ return err
+ }
+
+ b := bytes.NewReader(rels)
+ var rela Rela32
+
+ for b.Len() > 0 {
+ binary.Read(b, f.ByteOrder, &rela)
+ symNo := rela.Info >> 8
+ t := R_PPC(rela.Info & 0xff)
+
+ if symNo == 0 || symNo > uint32(len(symbols)) {
+ continue
+ }
+ sym := &symbols[symNo-1]
+ if SymType(sym.Info&0xf) != STT_SECTION {
+ // We don't handle non-section relocations for now.
+ continue
+ }
+
+ switch t {
+ case R_PPC_ADDR32:
+ if rela.Off+4 >= uint32(len(dst)) || rela.Addend < 0 {
+ continue
+ }
+ f.ByteOrder.PutUint32(dst[rela.Off:rela.Off+4],
uint32(rela.Addend))
+ }
+ }
+
+ return nil
+}
+
func (f *File) applyRelocationsPPC64(dst []byte, rels []byte) error {
// 24 is the size of Rela64.
if len(rels)%24 != 0 {
diff -r 6ed23fc8eac4 libgo/go/debug/elf/file_test.go
--- a/libgo/go/debug/elf/file_test.go Tue Mar 24 12:43:53 2015 -0700
+++ b/libgo/go/debug/elf/file_test.go Tue Mar 24 13:51:18 2015 -0700
@@ -261,6 +261,12 @@
},
},
{
+ "testdata/go-relocation-test-gcc5-ppc.obj",
+ []relocationTestEntry{
+ {0, &dwarf.Entry{Offset: 0xb, Tag:
dwarf.TagCompileUnit, Children: true, Field: []dwarf.Field{dwarf.Field{Attr:
dwarf.AttrProducer, Val: "GNU C11 5.0.0 20150116 (experimental) -Asystem=linux
-Asystem=unix -Asystem=posix -g"}, dwarf.Field{Attr: dwarf.AttrLanguage, Val:
int64(12)}, dwarf.Field{Attr: dwarf.AttrName, Val:
"go-relocation-test-gcc5-ppc.c"}, dwarf.Field{Attr: dwarf.AttrCompDir, Val:
"/tmp"}, dwarf.Field{Attr: dwarf.AttrLowpc, Val: uint64(0x0)},
dwarf.Field{Attr: dwarf.AttrHighpc, Val: int64(0x44)}, dwarf.Field{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 -r 6ed23fc8eac4 libgo/go/debug/elf/testdata/go-relocation-test-gcc5-ppc.obj
Binary file libgo/go/debug/elf/testdata/go-relocation-test-gcc5-ppc.obj has
changed
