From a8c5a994d62cc920c134426f7eae892b013ee32d Mon Sep 17 00:00:00 2001 From: Jay Conrod Date: Thu, 30 Sep 2021 13:16:33 -0700 Subject: [PATCH] cmd/go: migrate 'go version' to use buildinfo.ReadFile The same code was copied into debug/buildinfo. 'go version' doesn't need its own copy. For #37475 Change-Id: I9e473ce574139a87a5f9c63229f0fc7ffac447a0 Reviewed-on: https://go-review.googlesource.com/c/go/+/353929 Trust: Jay Conrod Run-TryBot: Jay Conrod Reviewed-by: Bryan C. Mills --- src/cmd/go/internal/version/exe.go | 263 ------------------------- src/cmd/go/internal/version/version.go | 92 ++------- 2 files changed, 14 insertions(+), 341 deletions(-) delete mode 100644 src/cmd/go/internal/version/exe.go diff --git a/src/cmd/go/internal/version/exe.go b/src/cmd/go/internal/version/exe.go deleted file mode 100644 index 0e7deef149..0000000000 --- a/src/cmd/go/internal/version/exe.go +++ /dev/null @@ -1,263 +0,0 @@ -// Copyright 2019 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. - -package version - -import ( - "bytes" - "debug/elf" - "debug/macho" - "debug/pe" - "fmt" - "internal/xcoff" - "io" - "os" -) - -// An exe is a generic interface to an OS executable (ELF, Mach-O, PE, XCOFF). -type exe interface { - // Close closes the underlying file. - Close() error - - // ReadData reads and returns up to size byte starting at virtual address addr. - ReadData(addr, size uint64) ([]byte, error) - - // DataStart returns the writable data segment start address. - DataStart() uint64 -} - -// openExe opens file and returns it as an exe. -func openExe(file string) (exe, error) { - f, err := os.Open(file) - if err != nil { - return nil, err - } - data := make([]byte, 16) - if _, err := io.ReadFull(f, data); err != nil { - return nil, err - } - f.Seek(0, 0) - if bytes.HasPrefix(data, []byte("\x7FELF")) { - e, err := elf.NewFile(f) - if err != nil { - f.Close() - return nil, err - } - return &elfExe{f, e}, nil - } - if bytes.HasPrefix(data, []byte("MZ")) { - e, err := pe.NewFile(f) - if err != nil { - f.Close() - return nil, err - } - return &peExe{f, e}, nil - } - if bytes.HasPrefix(data, []byte("\xFE\xED\xFA")) || bytes.HasPrefix(data[1:], []byte("\xFA\xED\xFE")) { - e, err := macho.NewFile(f) - if err != nil { - f.Close() - return nil, err - } - return &machoExe{f, e}, nil - } - if bytes.HasPrefix(data, []byte{0x01, 0xDF}) || bytes.HasPrefix(data, []byte{0x01, 0xF7}) { - e, err := xcoff.NewFile(f) - if err != nil { - f.Close() - return nil, err - } - return &xcoffExe{f, e}, nil - - } - return nil, fmt.Errorf("unrecognized executable format") -} - -// elfExe is the ELF implementation of the exe interface. -type elfExe struct { - os *os.File - f *elf.File -} - -func (x *elfExe) Close() error { - return x.os.Close() -} - -func (x *elfExe) ReadData(addr, size uint64) ([]byte, error) { - for _, prog := range x.f.Progs { - if prog.Vaddr <= addr && addr <= prog.Vaddr+prog.Filesz-1 { - n := prog.Vaddr + prog.Filesz - addr - if n > size { - n = size - } - data := make([]byte, n) - _, err := prog.ReadAt(data, int64(addr-prog.Vaddr)) - if err != nil { - return nil, err - } - return data, nil - } - } - return nil, fmt.Errorf("address not mapped") -} - -func (x *elfExe) DataStart() uint64 { - for _, s := range x.f.Sections { - if s.Name == ".go.buildinfo" { - return s.Addr - } - } - for _, p := range x.f.Progs { - if p.Type == elf.PT_LOAD && p.Flags&(elf.PF_X|elf.PF_W) == elf.PF_W { - return p.Vaddr - } - } - return 0 -} - -// peExe is the PE (Windows Portable Executable) implementation of the exe interface. -type peExe struct { - os *os.File - f *pe.File -} - -func (x *peExe) Close() error { - return x.os.Close() -} - -func (x *peExe) imageBase() uint64 { - switch oh := x.f.OptionalHeader.(type) { - case *pe.OptionalHeader32: - return uint64(oh.ImageBase) - case *pe.OptionalHeader64: - return oh.ImageBase - } - return 0 -} - -func (x *peExe) ReadData(addr, size uint64) ([]byte, error) { - addr -= x.imageBase() - for _, sect := range x.f.Sections { - if uint64(sect.VirtualAddress) <= addr && addr <= uint64(sect.VirtualAddress+sect.Size-1) { - n := uint64(sect.VirtualAddress+sect.Size) - addr - if n > size { - n = size - } - data := make([]byte, n) - _, err := sect.ReadAt(data, int64(addr-uint64(sect.VirtualAddress))) - if err != nil { - return nil, err - } - return data, nil - } - } - return nil, fmt.Errorf("address not mapped") -} - -func (x *peExe) DataStart() uint64 { - // Assume data is first writable section. - const ( - IMAGE_SCN_CNT_CODE = 0x00000020 - IMAGE_SCN_CNT_INITIALIZED_DATA = 0x00000040 - IMAGE_SCN_CNT_UNINITIALIZED_DATA = 0x00000080 - IMAGE_SCN_MEM_EXECUTE = 0x20000000 - IMAGE_SCN_MEM_READ = 0x40000000 - IMAGE_SCN_MEM_WRITE = 0x80000000 - IMAGE_SCN_MEM_DISCARDABLE = 0x2000000 - IMAGE_SCN_LNK_NRELOC_OVFL = 0x1000000 - IMAGE_SCN_ALIGN_32BYTES = 0x600000 - ) - for _, sect := range x.f.Sections { - if sect.VirtualAddress != 0 && sect.Size != 0 && - sect.Characteristics&^IMAGE_SCN_ALIGN_32BYTES == IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_MEM_READ|IMAGE_SCN_MEM_WRITE { - return uint64(sect.VirtualAddress) + x.imageBase() - } - } - return 0 -} - -// machoExe is the Mach-O (Apple macOS/iOS) implementation of the exe interface. -type machoExe struct { - os *os.File - f *macho.File -} - -func (x *machoExe) Close() error { - return x.os.Close() -} - -func (x *machoExe) ReadData(addr, size uint64) ([]byte, error) { - for _, load := range x.f.Loads { - seg, ok := load.(*macho.Segment) - if !ok { - continue - } - if seg.Addr <= addr && addr <= seg.Addr+seg.Filesz-1 { - if seg.Name == "__PAGEZERO" { - continue - } - n := seg.Addr + seg.Filesz - addr - if n > size { - n = size - } - data := make([]byte, n) - _, err := seg.ReadAt(data, int64(addr-seg.Addr)) - if err != nil { - return nil, err - } - return data, nil - } - } - return nil, fmt.Errorf("address not mapped") -} - -func (x *machoExe) DataStart() uint64 { - // Look for section named "__go_buildinfo". - for _, sec := range x.f.Sections { - if sec.Name == "__go_buildinfo" { - return sec.Addr - } - } - // Try the first non-empty writable segment. - const RW = 3 - for _, load := range x.f.Loads { - seg, ok := load.(*macho.Segment) - if ok && seg.Addr != 0 && seg.Filesz != 0 && seg.Prot == RW && seg.Maxprot == RW { - return seg.Addr - } - } - return 0 -} - -// xcoffExe is the XCOFF (AIX eXtended COFF) implementation of the exe interface. -type xcoffExe struct { - os *os.File - f *xcoff.File -} - -func (x *xcoffExe) Close() error { - return x.os.Close() -} - -func (x *xcoffExe) ReadData(addr, size uint64) ([]byte, error) { - for _, sect := range x.f.Sections { - if uint64(sect.VirtualAddress) <= addr && addr <= uint64(sect.VirtualAddress+sect.Size-1) { - n := uint64(sect.VirtualAddress+sect.Size) - addr - if n > size { - n = size - } - data := make([]byte, n) - _, err := sect.ReadAt(data, int64(addr-uint64(sect.VirtualAddress))) - if err != nil { - return nil, err - } - return data, nil - } - } - return nil, fmt.Errorf("address not mapped") -} - -func (x *xcoffExe) DataStart() uint64 { - return x.f.SectionByType(xcoff.STYP_DATA).VirtualAddress -} diff --git a/src/cmd/go/internal/version/version.go b/src/cmd/go/internal/version/version.go index e885933ac3..febc7c638a 100644 --- a/src/cmd/go/internal/version/version.go +++ b/src/cmd/go/internal/version/version.go @@ -8,7 +8,8 @@ package version import ( "bytes" "context" - "encoding/binary" + "debug/buildinfo" + "errors" "fmt" "io/fs" "os" @@ -141,90 +142,25 @@ func scanFile(file string, info fs.FileInfo, mustPrint bool) { return } - x, err := openExe(file) + bi, err := buildinfo.ReadFile(file) if err != nil { if mustPrint { - fmt.Fprintf(os.Stderr, "%s: %v\n", file, err) + if pathErr := (*os.PathError)(nil); errors.As(err, &pathErr) && filepath.Clean(pathErr.Path) == filepath.Clean(file) { + fmt.Fprintf(os.Stderr, "%v\n", file) + } else { + fmt.Fprintf(os.Stderr, "%s: %v\n", file, err) + } } - return - } - defer x.Close() - - vers, mod := findVers(x) - if vers == "" { - if mustPrint { - fmt.Fprintf(os.Stderr, "%s: go version not found\n", file) - } - return } - fmt.Printf("%s: %s\n", file, vers) - if *versionM && mod != "" { - fmt.Printf("\t%s\n", strings.ReplaceAll(mod[:len(mod)-1], "\n", "\n\t")) - } -} - -// The build info blob left by the linker is identified by -// a 16-byte header, consisting of buildInfoMagic (14 bytes), -// the binary's pointer size (1 byte), -// and whether the binary is big endian (1 byte). -var buildInfoMagic = []byte("\xff Go buildinf:") - -// findVers finds and returns the Go version and module version information -// in the executable x. -func findVers(x exe) (vers, mod string) { - // Read the first 64kB of text to find the build info blob. - text := x.DataStart() - data, err := x.ReadData(text, 64*1024) + fmt.Printf("%s: %s\n", file, bi.GoVersion) + bi.GoVersion = "" // suppress printing go version again + mod, err := bi.MarshalText() if err != nil { + fmt.Fprintf(os.Stderr, "%s: formatting build info: %v\n", file, err) return } - for ; !bytes.HasPrefix(data, buildInfoMagic); data = data[32:] { - if len(data) < 32 { - return - } + if *versionM && len(mod) > 0 { + fmt.Printf("\t%s\n", bytes.ReplaceAll(mod[:len(mod)-1], []byte("\n"), []byte("\n\t"))) } - - // Decode the blob. - ptrSize := int(data[14]) - bigEndian := data[15] != 0 - var bo binary.ByteOrder - if bigEndian { - bo = binary.BigEndian - } else { - bo = binary.LittleEndian - } - var readPtr func([]byte) uint64 - if ptrSize == 4 { - readPtr = func(b []byte) uint64 { return uint64(bo.Uint32(b)) } - } else { - readPtr = bo.Uint64 - } - vers = readString(x, ptrSize, readPtr, readPtr(data[16:])) - if vers == "" { - return - } - mod = readString(x, ptrSize, readPtr, readPtr(data[16+ptrSize:])) - if len(mod) >= 33 && mod[len(mod)-17] == '\n' { - // Strip module framing. - mod = mod[16 : len(mod)-16] - } else { - mod = "" - } - return -} - -// readString returns the string at address addr in the executable x. -func readString(x exe, ptrSize int, readPtr func([]byte) uint64, addr uint64) string { - hdr, err := x.ReadData(addr, uint64(2*ptrSize)) - if err != nil || len(hdr) < 2*ptrSize { - return "" - } - dataAddr := readPtr(hdr) - dataLen := readPtr(hdr[ptrSize:]) - data, err := x.ReadData(dataAddr, dataLen) - if err != nil || uint64(len(data)) < dataLen { - return "" - } - return string(data) }