cmd/pprof: fix addr calculation for Windows

This makes it possible to use `disasm` with ASLR windows binaries.

For #46639

Change-Id: I08aff38dc0b33fdfb07e0206766db066e33207d1
Reviewed-on: https://go-review.googlesource.com/c/go/+/416976
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Damien Neil <dneil@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

3 files changed, 22 insertions, 29 deletions

diff --git a/src/cmd/internal/objfile/pe.go b/src/cmd/internal/objfile/pe.go
index 9088866fcf..4c4be1e6b7 100644
--- a/src/cmd/internal/objfile/pe.go
+++ b/src/cmd/internal/objfile/pe.go
@@ -31,13 +31,7 @@ func (f *peFile) symbols() ([]Sym, error) {
 	// We infer the size of a symbol by looking at where the next symbol begins.
 	var addrs []uint64
 
-	var imageBase uint64
-	switch oh := f.pe.OptionalHeader.(type) {
-	case *pe.OptionalHeader32:
-		imageBase = uint64(oh.ImageBase)
-	case *pe.OptionalHeader64:
-		imageBase = oh.ImageBase
-	}
+	imageBase, _ := f.imageBase()
 
 	var syms []Sym
 	for _, s := range f.pe.Symbols {
@@ -96,15 +90,11 @@ func (f *peFile) symbols() ([]Sym, error) {
 }
 
 func (f *peFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
-	var imageBase uint64
-	switch oh := f.pe.OptionalHeader.(type) {
-	case *pe.OptionalHeader32:
-		imageBase = uint64(oh.ImageBase)
-	case *pe.OptionalHeader64:
-		imageBase = oh.ImageBase
-	default:
-		return 0, nil, nil, fmt.Errorf("pe file format not recognized")
+	imageBase, err := f.imageBase()
+	if err != nil {
+		return 0, nil, nil, err
 	}
+
 	if sect := f.pe.Section(".text"); sect != nil {
 		textStart = imageBase + uint64(sect.VirtualAddress)
 	}
@@ -127,15 +117,11 @@ func (f *peFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
 }
 
 func (f *peFile) text() (textStart uint64, text []byte, err error) {
-	var imageBase uint64
-	switch oh := f.pe.OptionalHeader.(type) {
-	case *pe.OptionalHeader32:
-		imageBase = uint64(oh.ImageBase)
-	case *pe.OptionalHeader64:
-		imageBase = oh.ImageBase
-	default:
-		return 0, nil, fmt.Errorf("pe file format not recognized")
+	imageBase, err := f.imageBase()
+	if err != nil {
+		return 0, nil, err
 	}
+
 	sect := f.pe.Section(".text")
 	if sect == nil {
 		return 0, nil, fmt.Errorf("text section not found")
@@ -197,7 +183,18 @@ func (f *peFile) goarch() string {
 }
 
 func (f *peFile) loadAddress() (uint64, error) {
-	return 0, fmt.Errorf("unknown load address")
+	return f.imageBase()
+}
+
+func (f *peFile) imageBase() (uint64, error) {
+	switch oh := f.pe.OptionalHeader.(type) {
+	case *pe.OptionalHeader32:
+		return uint64(oh.ImageBase), nil
+	case *pe.OptionalHeader64:
+		return oh.ImageBase, nil
+	default:
+		return 0, fmt.Errorf("pe file format not recognized")
+	}
 }
 
 func (f *peFile) dwarf() (*dwarf.Data, error) {
diff --git a/src/cmd/pprof/pprof.go b/src/cmd/pprof/pprof.go
index c073c964b4..147b3ad418 100644
--- a/src/cmd/pprof/pprof.go
+++ b/src/cmd/pprof/pprof.go
@@ -233,8 +233,7 @@ func (f *file) Name() string {
 }
 
 func (f *file) ObjAddr(addr uint64) (uint64, error) {
-	// No support for shared libraries, so translation is a no-op.
-	return addr, nil
+	return addr - f.offset, nil
 }
 
 func (f *file) BuildID() string {
diff --git a/src/cmd/pprof/pprof_test.go b/src/cmd/pprof/pprof_test.go
index 9a37b97286..e001975f83 100644
--- a/src/cmd/pprof/pprof_test.go
+++ b/src/cmd/pprof/pprof_test.go
@@ -83,9 +83,6 @@ func mustHaveDisasm(t *testing.T) {
 	}
 
 	// Skip PIE platforms, pprof can't disassemble PIE.
-	if runtime.GOOS == "windows" {
-		t.Skipf("skipping on %s, issue 46639", runtime.GOOS)
-	}
 	if runtime.GOOS == "darwin" && runtime.GOARCH == "arm64" {
 		t.Skipf("skipping on %s/%s, issue 46639", runtime.GOOS, runtime.GOARCH)
 	}