From d06815ba3f0a196adeacfbf5cc963fe2b7d42f46 Mon Sep 17 00:00:00 2001 From: David Crawshaw Date: Thu, 12 Oct 2017 13:38:45 -0400 Subject: [PATCH] cmd/link: split PE loader into its own package For #22095 Change-Id: I8f48fce571b69a7e8edf2ad7733ffdfd38676e63 Reviewed-on: https://go-review.googlesource.com/70310 Run-TryBot: David Crawshaw TryBot-Result: Gobot Gobot Reviewed-by: Ian Lance Taylor --- src/cmd/dist/buildtool.go | 3 +- src/cmd/link/internal/ld/lib.go | 12 +++ src/cmd/link/internal/ld/pe.go | 19 ++++ src/cmd/link/internal/{ld => loadpe}/ldpe.go | 95 ++++++++++---------- 4 files changed, 82 insertions(+), 47 deletions(-) rename src/cmd/link/internal/{ld => loadpe}/ldpe.go (79%) diff --git a/src/cmd/dist/buildtool.go b/src/cmd/dist/buildtool.go index 6eae8a7304c01..d86af557b24b9 100644 --- a/src/cmd/dist/buildtool.go +++ b/src/cmd/dist/buildtool.go @@ -67,8 +67,9 @@ var bootstrapDirs = []string{ "cmd/link/internal/arm", "cmd/link/internal/arm64", "cmd/link/internal/ld", - "cmd/link/internal/loadmacho", "cmd/link/internal/loadelf", + "cmd/link/internal/loadmacho", + "cmd/link/internal/loadpe", "cmd/link/internal/mips", "cmd/link/internal/mips64", "cmd/link/internal/objfile", diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go index 0a7c3f9fdf9b6..884d07339c69f 100644 --- a/src/cmd/link/internal/ld/lib.go +++ b/src/cmd/link/internal/ld/lib.go @@ -38,6 +38,7 @@ import ( "cmd/internal/sys" "cmd/link/internal/loadelf" "cmd/link/internal/loadmacho" + "cmd/link/internal/loadpe" "cmd/link/internal/objfile" "cmd/link/internal/sym" "crypto/sha1" @@ -1410,6 +1411,17 @@ func ldobj(ctxt *Link, f *bio.Reader, lib *sym.Library, length int64, pn string, } if c1 == 0x4c && c2 == 0x01 || c1 == 0x64 && c2 == 0x86 { + ldpe := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) { + textp, rsrc, err := loadpe.Load(ctxt.Arch, ctxt.Syms, f, pkg, length, pn) + if err != nil { + Errorf(nil, "%v", err) + return + } + if rsrc != nil { + setpersrc(ctxt, rsrc) + } + ctxt.Textp = append(ctxt.Textp, textp...) + } return ldhostobj(ldpe, f, pkg, length, pn, file) } diff --git a/src/cmd/link/internal/ld/pe.go b/src/cmd/link/internal/ld/pe.go index 7ebcd27550708..ac99a90e66e83 100644 --- a/src/cmd/link/internal/ld/pe.go +++ b/src/cmd/link/internal/ld/pe.go @@ -91,6 +91,25 @@ const ( IMAGE_SUBSYSTEM_WINDOWS_CUI = 3 ) +// TODO(crawshaw): add these constants to debug/pe. +const ( + IMAGE_SYM_TYPE_NULL = 0 + IMAGE_SYM_TYPE_STRUCT = 8 + IMAGE_SYM_DTYPE_FUNCTION = 0x20 + IMAGE_SYM_DTYPE_ARRAY = 0x30 + IMAGE_SYM_CLASS_EXTERNAL = 2 + IMAGE_SYM_CLASS_STATIC = 3 + + IMAGE_REL_I386_DIR32 = 0x0006 + IMAGE_REL_I386_SECREL = 0x000B + IMAGE_REL_I386_REL32 = 0x0014 + + IMAGE_REL_AMD64_ADDR64 = 0x0001 + IMAGE_REL_AMD64_ADDR32 = 0x0002 + IMAGE_REL_AMD64_REL32 = 0x0004 + IMAGE_REL_AMD64_SECREL = 0x000B +) + // Copyright 2009 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. diff --git a/src/cmd/link/internal/ld/ldpe.go b/src/cmd/link/internal/loadpe/ldpe.go similarity index 79% rename from src/cmd/link/internal/ld/ldpe.go rename to src/cmd/link/internal/loadpe/ldpe.go index 5a76f768768a5..5f62760c2088b 100644 --- a/src/cmd/link/internal/ld/ldpe.go +++ b/src/cmd/link/internal/loadpe/ldpe.go @@ -2,7 +2,8 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. -package ld +// Package loadpe implements a PE/COFF file reader. +package loadpe import ( "cmd/internal/bio" @@ -10,10 +11,10 @@ import ( "cmd/internal/sys" "cmd/link/internal/sym" "debug/pe" + "encoding/binary" "errors" "fmt" "io" - "log" "sort" "strings" ) @@ -102,6 +103,17 @@ const ( IMAGE_REL_AMD64_SSPAN32 = 0x0010 ) +// TODO(crawshaw): de-duplicate these symbols with cmd/internal/ld, ideally in debug/pe. +const ( + IMAGE_SCN_CNT_CODE = 0x00000020 + IMAGE_SCN_CNT_INITIALIZED_DATA = 0x00000040 + IMAGE_SCN_CNT_UNINITIALIZED_DATA = 0x00000080 + IMAGE_SCN_MEM_DISCARDABLE = 0x02000000 + IMAGE_SCN_MEM_EXECUTE = 0x20000000 + IMAGE_SCN_MEM_READ = 0x40000000 + IMAGE_SCN_MEM_WRITE = 0x80000000 +) + // TODO(brainman): maybe just add ReadAt method to bio.Reader instead of creating peBiobuf // peBiobuf makes bio.Reader look like io.ReaderAt. @@ -119,19 +131,11 @@ func (f *peBiobuf) ReadAt(p []byte, off int64) (int, error) { return n, nil } -func ldpe(ctxt *Link, input *bio.Reader, pkg string, length int64, pn string) { - err := ldpeError(ctxt, input, pkg, length, pn) - if err != nil { - Errorf(nil, "%s: malformed pe file: %v", pn, err) - } -} - -func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn string) error { - if ctxt.Debugvlog != 0 { - ctxt.Logf("%5.2f ldpe %s\n", Cputime(), pn) - } - - localSymVersion := ctxt.Syms.IncVersion() +// Load loads the PE file pn from input. +// Symbols are written into syms, and a slice of the text symbols is returned. +// If an .rsrc section is found, its symbol is returned as rsrc. +func Load(arch *sys.Arch, syms *sym.Symbols, input *bio.Reader, pkg string, length int64, pn string) (textp []*sym.Symbol, rsrc *sym.Symbol, err error) { + localSymVersion := syms.IncVersion() sectsyms := make(map[*pe.Section]*sym.Symbol) sectdata := make(map[*pe.Section][]byte) @@ -145,7 +149,7 @@ func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn strin // TODO: replace pe.NewFile with pe.Load (grep for "add Load function" in debug/pe for details) f, err := pe.NewFile(sr) if err != nil { - return err + return nil, nil, err } defer f.Close() @@ -164,7 +168,7 @@ func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn strin } name := fmt.Sprintf("%s(%s)", pkg, sect.Name) - s := ctxt.Syms.Lookup(name, localSymVersion) + s := syms.Lookup(name, localSymVersion) switch sect.Characteristics & (IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE | IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE) { case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ: //.rdata @@ -180,13 +184,13 @@ func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn strin s.Type = sym.STEXT default: - return fmt.Errorf("unexpected flags %#06x for PE section %s", sect.Characteristics, sect.Name) + return nil, nil, fmt.Errorf("unexpected flags %#06x for PE section %s", sect.Characteristics, sect.Name) } if s.Type != sym.SNOPTRBSS { data, err := sect.Data() if err != nil { - return err + return nil, nil, err } sectdata[sect] = data s.P = data @@ -194,7 +198,7 @@ func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn strin s.Size = int64(sect.Size) sectsyms[sect] = s if sect.Name == ".rsrc" { - setpersrc(ctxt, s) + rsrc = s } } @@ -219,19 +223,19 @@ func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn strin for j, r := range rsect.Relocs { rp := &rs[j] if int(r.SymbolTableIndex) >= len(f.COFFSymbols) { - return fmt.Errorf("relocation number %d symbol index idx=%d cannot be large then number of symbols %d", j, r.SymbolTableIndex, len(f.COFFSymbols)) + return nil, nil, fmt.Errorf("relocation number %d symbol index idx=%d cannot be large then number of symbols %d", j, r.SymbolTableIndex, len(f.COFFSymbols)) } pesym := &f.COFFSymbols[r.SymbolTableIndex] - gosym, err := readpesym(ctxt, f, pesym, sectsyms, localSymVersion) + gosym, err := readpesym(arch, syms, f, pesym, sectsyms, localSymVersion) if err != nil { - return err + return nil, nil, err } if gosym == nil { name, err := pesym.FullName(f.StringTable) if err != nil { name = string(pesym.Name[:]) } - return fmt.Errorf("reloc of invalid sym %s idx=%d type=%d", name, r.SymbolTableIndex, pesym.Type) + return nil, nil, fmt.Errorf("reloc of invalid sym %s idx=%d type=%d", name, r.SymbolTableIndex, pesym.Type) } rp.Sym = gosym @@ -239,21 +243,20 @@ func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn strin rp.Off = int32(r.VirtualAddress) switch r.Type { default: - Errorf(sectsyms[rsect], "%s: unknown relocation type %d;", pn, r.Type) - fallthrough + return nil, nil, fmt.Errorf("%s: %v: unknown relocation type %v", pn, sectsyms[rsect], r.Type) case IMAGE_REL_I386_REL32, IMAGE_REL_AMD64_REL32, IMAGE_REL_AMD64_ADDR32, // R_X86_64_PC32 IMAGE_REL_AMD64_ADDR32NB: rp.Type = objabi.R_PCREL - rp.Add = int64(int32(Le32(sectdata[rsect][rp.Off:]))) + rp.Add = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rp.Off:]))) case IMAGE_REL_I386_DIR32NB, IMAGE_REL_I386_DIR32: rp.Type = objabi.R_ADDR // load addend from image - rp.Add = int64(int32(Le32(sectdata[rsect][rp.Off:]))) + rp.Add = int64(int32(binary.LittleEndian.Uint32(sectdata[rsect][rp.Off:]))) case IMAGE_REL_AMD64_ADDR64: // R_X86_64_64 rp.Siz = 8 @@ -261,7 +264,7 @@ func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn strin rp.Type = objabi.R_ADDR // load addend from image - rp.Add = int64(Le64(sectdata[rsect][rp.Off:])) + rp.Add = int64(binary.LittleEndian.Uint64(sectdata[rsect][rp.Off:])) } // ld -r could generate multiple section symbols for the @@ -287,7 +290,7 @@ func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn strin name, err := pesym.FullName(f.StringTable) if err != nil { - return err + return nil, nil, err } if name == "" { continue @@ -309,9 +312,9 @@ func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn strin } } - s, err := readpesym(ctxt, f, pesym, sectsyms, localSymVersion) + s, err := readpesym(arch, syms, f, pesym, sectsyms, localSymVersion) if err != nil { - return err + return nil, nil, err } if pesym.SectionNumber == 0 { // extern @@ -327,21 +330,21 @@ func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn strin } else if pesym.SectionNumber > 0 && int(pesym.SectionNumber) <= len(f.Sections) { sect = f.Sections[pesym.SectionNumber-1] if _, found := sectsyms[sect]; !found { - Errorf(s, "%s: missing sect.sym", pn) + return nil, nil, fmt.Errorf("%s: %v: missing sect.sym", pn, s) } } else { - Errorf(s, "%s: sectnum < 0!", pn) + return nil, nil, fmt.Errorf("%s: %v: sectnum < 0!", pn, s) } if sect == nil { - return nil + return nil, rsrc, nil } if s.Outer != nil { if s.Attr.DuplicateOK() { continue } - Exitf("%s: duplicate symbol reference: %s in both %s and %s", pn, s.Name, s.Outer.Name, sectsyms[sect].Name) + return nil, nil, fmt.Errorf("%s: duplicate symbol reference: %s in both %s and %s", pn, s.Name, s.Outer.Name, sectsyms[sect].Name) } sectsym := sectsyms[sect] @@ -353,7 +356,7 @@ func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn strin s.Outer = sectsym if sectsym.Type == sym.STEXT { if s.Attr.External() && !s.Attr.DuplicateOK() { - Errorf(s, "%s: duplicate symbol definition", pn) + return nil, nil, fmt.Errorf("%s: duplicate symbol definition", s.Name) } s.Attr |= sym.AttrExternal } @@ -371,28 +374,28 @@ func ldpeError(ctxt *Link, input *bio.Reader, pkg string, length int64, pn strin } if s.Type == sym.STEXT { if s.Attr.OnList() { - log.Fatalf("symbol %s listed multiple times", s.Name) + return nil, nil, fmt.Errorf("symbol %s listed multiple times", s.Name) } s.Attr |= sym.AttrOnList - ctxt.Textp = append(ctxt.Textp, s) + textp = append(textp, s) for s = s.Sub; s != nil; s = s.Sub { if s.Attr.OnList() { - log.Fatalf("symbol %s listed multiple times", s.Name) + return nil, nil, fmt.Errorf("symbol %s listed multiple times", s.Name) } s.Attr |= sym.AttrOnList - ctxt.Textp = append(ctxt.Textp, s) + textp = append(textp, s) } } } - return nil + return textp, rsrc, nil } func issect(s *pe.COFFSymbol) bool { return s.StorageClass == IMAGE_SYM_CLASS_STATIC && s.Type == 0 && s.Name[0] == '.' } -func readpesym(ctxt *Link, f *pe.File, pesym *pe.COFFSymbol, sectsyms map[*pe.Section]*sym.Symbol, localSymVersion int) (*sym.Symbol, error) { +func readpesym(arch *sys.Arch, syms *sym.Symbols, f *pe.File, pesym *pe.COFFSymbol, sectsyms map[*pe.Section]*sym.Symbol, localSymVersion int) (*sym.Symbol, error) { symname, err := pesym.FullName(f.StringTable) if err != nil { return nil, err @@ -405,7 +408,7 @@ func readpesym(ctxt *Link, f *pe.File, pesym *pe.COFFSymbol, sectsyms map[*pe.Se if strings.HasPrefix(name, "__imp_") { name = name[6:] // __imp_Name => Name } - if ctxt.Arch.Family == sys.I386 && name[0] == '_' { + if arch.Family == sys.I386 && name[0] == '_' { name = name[1:] // _Name => Name } } @@ -423,10 +426,10 @@ func readpesym(ctxt *Link, f *pe.File, pesym *pe.COFFSymbol, sectsyms map[*pe.Se case IMAGE_SYM_DTYPE_FUNCTION, IMAGE_SYM_DTYPE_NULL: switch pesym.StorageClass { case IMAGE_SYM_CLASS_EXTERNAL: //global - s = ctxt.Syms.Lookup(name, 0) + s = syms.Lookup(name, 0) case IMAGE_SYM_CLASS_NULL, IMAGE_SYM_CLASS_STATIC, IMAGE_SYM_CLASS_LABEL: - s = ctxt.Syms.Lookup(name, localSymVersion) + s = syms.Lookup(name, localSymVersion) s.Attr |= sym.AttrDuplicateOK default: