--- /dev/null
+// Copyright 2017 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.
+
+// linux/mkall.go - Generates all Linux zsysnum, zsyscall, zerror, and ztype
+// files for all Linux architectures supported by the go compiler. See
+// README.md for more information about the build system.
+
+// To run it you must have a git checkout of the Linux kernel and glibc. Once
+// the appropriate sources are ready, the program is run as:
+// go run linux/mkall.go <linux_dir> <glibc_dir>
+
+// +build ignore
+
+package main
+
+import (
+ "bufio"
+ "bytes"
+ "debug/elf"
+ "encoding/binary"
+ "errors"
+ "fmt"
+ "io"
+ "io/ioutil"
+ "os"
+ "os/exec"
+ "path/filepath"
+ "runtime"
+ "strings"
+ "unicode"
+)
+
+// These will be paths to the appropriate source directories.
+var LinuxDir string
+var GlibcDir string
+
+const TempDir = "/tmp"
+const IncludeDir = TempDir + "/include" // To hold our C headers
+const BuildDir = TempDir + "/build" // To hold intermediate build files
+
+const GOOS = "linux" // Only for Linux targets
+const BuildArch = "amd64" // Must be built on this architecture
+const MinKernel = "2.6.23" // https://golang.org/doc/install#requirements
+
+type target struct {
+ GoArch string // Architecture name according to Go
+ LinuxArch string // Architecture name according to the Linux Kernel
+ GNUArch string // Architecture name according to GNU tools (https://wiki.debian.org/Multiarch/Tuples)
+ BigEndian bool // Default Little Endian
+ SignedChar bool // Is -fsigned-char needed (default no)
+ Bits int
+}
+
+// List of all Linux targets supported by the go compiler. Currently, riscv64
+// and sparc64 are not fully supported, but there is enough support already to
+// generate Go type and error definitions.
+var targets = []target{
+ {
+ GoArch: "386",
+ LinuxArch: "x86",
+ GNUArch: "i686-linux-gnu", // Note "i686" not "i386"
+ Bits: 32,
+ },
+ {
+ GoArch: "amd64",
+ LinuxArch: "x86",
+ GNUArch: "x86_64-linux-gnu",
+ Bits: 64,
+ },
+ {
+ GoArch: "arm64",
+ LinuxArch: "arm64",
+ GNUArch: "aarch64-linux-gnu",
+ SignedChar: true,
+ Bits: 64,
+ },
+ {
+ GoArch: "arm",
+ LinuxArch: "arm",
+ GNUArch: "arm-linux-gnueabi",
+ Bits: 32,
+ },
+ {
+ GoArch: "mips",
+ LinuxArch: "mips",
+ GNUArch: "mips-linux-gnu",
+ BigEndian: true,
+ Bits: 32,
+ },
+ {
+ GoArch: "mipsle",
+ LinuxArch: "mips",
+ GNUArch: "mipsel-linux-gnu",
+ Bits: 32,
+ },
+ {
+ GoArch: "mips64",
+ LinuxArch: "mips",
+ GNUArch: "mips64-linux-gnuabi64",
+ BigEndian: true,
+ Bits: 64,
+ },
+ {
+ GoArch: "mips64le",
+ LinuxArch: "mips",
+ GNUArch: "mips64el-linux-gnuabi64",
+ Bits: 64,
+ },
+ {
+ GoArch: "ppc64",
+ LinuxArch: "powerpc",
+ GNUArch: "powerpc64-linux-gnu",
+ BigEndian: true,
+ Bits: 64,
+ },
+ {
+ GoArch: "ppc64le",
+ LinuxArch: "powerpc",
+ GNUArch: "powerpc64le-linux-gnu",
+ Bits: 64,
+ },
+ {
+ GoArch: "riscv64",
+ LinuxArch: "riscv",
+ GNUArch: "riscv64-linux-gnu",
+ Bits: 64,
+ },
+ {
+ GoArch: "s390x",
+ LinuxArch: "s390",
+ GNUArch: "s390x-linux-gnu",
+ BigEndian: true,
+ SignedChar: true,
+ Bits: 64,
+ },
+ {
+ GoArch: "sparc64",
+ LinuxArch: "sparc",
+ GNUArch: "sparc64-linux-gnu",
+ BigEndian: true,
+ Bits: 64,
+ },
+}
+
+// ptracePairs is a list of pairs of targets that can, in some cases,
+// run each other's binaries. 'archName' is the combined name of 'a1'
+// and 'a2', which is used in the file name. Generally we use an 'x'
+// suffix in the file name to indicate that the file works for both
+// big-endian and little-endian, here we use 'nn' to indicate that this
+// file is suitable for 32-bit and 64-bit.
+var ptracePairs = []struct{ a1, a2, archName string }{
+ {"386", "amd64", "x86"},
+ {"arm", "arm64", "armnn"},
+ {"mips", "mips64", "mipsnn"},
+ {"mipsle", "mips64le", "mipsnnle"},
+}
+
+func main() {
+ if runtime.GOOS != GOOS || runtime.GOARCH != BuildArch {
+ fmt.Printf("Build system has GOOS_GOARCH = %s_%s, need %s_%s\n",
+ runtime.GOOS, runtime.GOARCH, GOOS, BuildArch)
+ return
+ }
+
+ // Check that we are using the new build system if we should
+ if os.Getenv("GOLANG_SYS_BUILD") != "docker" {
+ fmt.Println("In the new build system, mkall.go should not be called directly.")
+ fmt.Println("See README.md")
+ return
+ }
+
+ // Parse the command line options
+ if len(os.Args) != 3 {
+ fmt.Println("USAGE: go run linux/mkall.go <linux_dir> <glibc_dir>")
+ return
+ }
+ LinuxDir = os.Args[1]
+ GlibcDir = os.Args[2]
+
+ for _, t := range targets {
+ fmt.Printf("----- GENERATING: %s -----\n", t.GoArch)
+ if err := t.generateFiles(); err != nil {
+ fmt.Printf("%v\n***** FAILURE: %s *****\n\n", err, t.GoArch)
+ } else {
+ fmt.Printf("----- SUCCESS: %s -----\n\n", t.GoArch)
+ }
+ }
+
+ fmt.Printf("----- GENERATING: merging generated files -----\n")
+ if err := mergeFiles(); err != nil {
+ fmt.Printf("%v\n***** FAILURE: merging generated files *****\n\n", err)
+ } else {
+ fmt.Printf("----- SUCCESS: merging generated files -----\n\n")
+ }
+
+ fmt.Printf("----- GENERATING ptrace pairs -----\n")
+ ok := true
+ for _, p := range ptracePairs {
+ if err := generatePtracePair(p.a1, p.a2, p.archName); err != nil {
+ fmt.Printf("%v\n***** FAILURE: %s/%s *****\n\n", err, p.a1, p.a2)
+ ok = false
+ }
+ }
+ // generate functions PtraceGetRegSetArm64 and PtraceSetRegSetArm64.
+ if err := generatePtraceRegSet("arm64"); err != nil {
+ fmt.Printf("%v\n***** FAILURE: generatePtraceRegSet(%q) *****\n\n", err, "arm64")
+ ok = false
+ }
+ if ok {
+ fmt.Printf("----- SUCCESS ptrace pairs -----\n\n")
+ }
+}
+
+// Makes an exec.Cmd with Stderr attached to os.Stderr
+func makeCommand(name string, args ...string) *exec.Cmd {
+ cmd := exec.Command(name, args...)
+ cmd.Stderr = os.Stderr
+ return cmd
+}
+
+// Set GOARCH for target and build environments.
+func (t *target) setTargetBuildArch(cmd *exec.Cmd) {
+ // Set GOARCH_TARGET so command knows what GOARCH is..
+ cmd.Env = append(os.Environ(), "GOARCH_TARGET="+t.GoArch)
+ // Set GOARCH to host arch for command, so it can run natively.
+ for i, s := range cmd.Env {
+ if strings.HasPrefix(s, "GOARCH=") {
+ cmd.Env[i] = "GOARCH=" + BuildArch
+ }
+ }
+}
+
+// Runs the command, pipes output to a formatter, pipes that to an output file.
+func (t *target) commandFormatOutput(formatter string, outputFile string,
+ name string, args ...string) (err error) {
+ mainCmd := makeCommand(name, args...)
+ if name == "mksyscall" {
+ args = append([]string{"run", "mksyscall.go"}, args...)
+ mainCmd = makeCommand("go", args...)
+ t.setTargetBuildArch(mainCmd)
+ } else if name == "mksysnum" {
+ args = append([]string{"run", "linux/mksysnum.go"}, args...)
+ mainCmd = makeCommand("go", args...)
+ t.setTargetBuildArch(mainCmd)
+ }
+
+ fmtCmd := makeCommand(formatter)
+ if formatter == "mkpost" {
+ fmtCmd = makeCommand("go", "run", "mkpost.go")
+ t.setTargetBuildArch(fmtCmd)
+ }
+
+ // mainCmd | fmtCmd > outputFile
+ if fmtCmd.Stdin, err = mainCmd.StdoutPipe(); err != nil {
+ return
+ }
+ if fmtCmd.Stdout, err = os.Create(outputFile); err != nil {
+ return
+ }
+
+ // Make sure the formatter eventually closes
+ if err = fmtCmd.Start(); err != nil {
+ return
+ }
+ defer func() {
+ fmtErr := fmtCmd.Wait()
+ if err == nil {
+ err = fmtErr
+ }
+ }()
+
+ return mainCmd.Run()
+}
+
+// Generates all the files for a Linux target
+func (t *target) generateFiles() error {
+ // Setup environment variables
+ os.Setenv("GOOS", GOOS)
+ os.Setenv("GOARCH", t.GoArch)
+
+ // Get appropriate compiler and emulator (unless on x86)
+ if t.LinuxArch != "x86" {
+ // Check/Setup cross compiler
+ compiler := t.GNUArch + "-gcc"
+ if _, err := exec.LookPath(compiler); err != nil {
+ return err
+ }
+ os.Setenv("CC", compiler)
+
+ // Check/Setup emulator (usually first component of GNUArch)
+ qemuArchName := t.GNUArch[:strings.Index(t.GNUArch, "-")]
+ if t.LinuxArch == "powerpc" {
+ qemuArchName = t.GoArch
+ }
+ // Fake uname for QEMU to allow running on Host kernel version < 4.15
+ if t.LinuxArch == "riscv" {
+ os.Setenv("QEMU_UNAME", "4.15")
+ }
+ os.Setenv("GORUN", "qemu-"+qemuArchName)
+ } else {
+ os.Setenv("CC", "gcc")
+ }
+
+ // Make the include directory and fill it with headers
+ if err := os.MkdirAll(IncludeDir, os.ModePerm); err != nil {
+ return err
+ }
+ defer os.RemoveAll(IncludeDir)
+ if err := t.makeHeaders(); err != nil {
+ return fmt.Errorf("could not make header files: %v", err)
+ }
+ fmt.Println("header files generated")
+
+ // Make each of the four files
+ if err := t.makeZSysnumFile(); err != nil {
+ return fmt.Errorf("could not make zsysnum file: %v", err)
+ }
+ fmt.Println("zsysnum file generated")
+
+ if err := t.makeZSyscallFile(); err != nil {
+ return fmt.Errorf("could not make zsyscall file: %v", err)
+ }
+ fmt.Println("zsyscall file generated")
+
+ if err := t.makeZTypesFile(); err != nil {
+ return fmt.Errorf("could not make ztypes file: %v", err)
+ }
+ fmt.Println("ztypes file generated")
+
+ if err := t.makeZErrorsFile(); err != nil {
+ return fmt.Errorf("could not make zerrors file: %v", err)
+ }
+ fmt.Println("zerrors file generated")
+
+ return nil
+}
+
+// Create the Linux, glibc and ABI (C compiler convention) headers in the include directory.
+func (t *target) makeHeaders() error {
+ // Make the Linux headers we need for this architecture
+ linuxMake := makeCommand("make", "headers_install", "ARCH="+t.LinuxArch, "INSTALL_HDR_PATH="+TempDir)
+ linuxMake.Dir = LinuxDir
+ if err := linuxMake.Run(); err != nil {
+ return err
+ }
+
+ // A Temporary build directory for glibc
+ if err := os.MkdirAll(BuildDir, os.ModePerm); err != nil {
+ return err
+ }
+ defer os.RemoveAll(BuildDir)
+
+ // Make the glibc headers we need for this architecture
+ confScript := filepath.Join(GlibcDir, "configure")
+ glibcConf := makeCommand(confScript, "--prefix="+TempDir, "--host="+t.GNUArch, "--enable-kernel="+MinKernel)
+ glibcConf.Dir = BuildDir
+ if err := glibcConf.Run(); err != nil {
+ return err
+ }
+ glibcMake := makeCommand("make", "install-headers")
+ glibcMake.Dir = BuildDir
+ if err := glibcMake.Run(); err != nil {
+ return err
+ }
+ // We only need an empty stubs file
+ stubsFile := filepath.Join(IncludeDir, "gnu/stubs.h")
+ if file, err := os.Create(stubsFile); err != nil {
+ return err
+ } else {
+ file.Close()
+ }
+
+ // ABI headers will specify C compiler behavior for the target platform.
+ return t.makeABIHeaders()
+}
+
+// makeABIHeaders generates C header files based on the platform's calling convention.
+// While many platforms have formal Application Binary Interfaces, in practice, whatever the
+// dominant C compilers generate is the de-facto calling convention.
+//
+// We generate C headers instead of a Go file, so as to enable references to the ABI from Cgo.
+func (t *target) makeABIHeaders() (err error) {
+ abiDir := filepath.Join(IncludeDir, "abi")
+ if err = os.Mkdir(abiDir, os.ModePerm); err != nil {
+ return err
+ }
+
+ cc := os.Getenv("CC")
+ if cc == "" {
+ return errors.New("CC (compiler) env var not set")
+ }
+
+ // Build a sacrificial ELF file, to mine for C compiler behavior.
+ binPath := filepath.Join(TempDir, "tmp_abi.o")
+ bin, err := t.buildELF(cc, cCode, binPath)
+ if err != nil {
+ return fmt.Errorf("cannot build ELF to analyze: %v", err)
+ }
+ defer bin.Close()
+ defer os.Remove(binPath)
+
+ // Right now, we put everything in abi.h, but we may change this later.
+ abiFile, err := os.Create(filepath.Join(abiDir, "abi.h"))
+ if err != nil {
+ return err
+ }
+ defer func() {
+ if cerr := abiFile.Close(); cerr != nil && err == nil {
+ err = cerr
+ }
+ }()
+
+ if err = t.writeBitFieldMasks(bin, abiFile); err != nil {
+ return fmt.Errorf("cannot write bitfield masks: %v", err)
+ }
+
+ return nil
+}
+
+func (t *target) buildELF(cc, src, path string) (*elf.File, error) {
+ // Compile the cCode source using the set compiler - we will need its .data section.
+ // Do not link the binary, so that we can find .data section offsets from the symbol values.
+ ccCmd := makeCommand(cc, "-o", path, "-gdwarf", "-x", "c", "-c", "-")
+ ccCmd.Stdin = strings.NewReader(src)
+ ccCmd.Stdout = os.Stdout
+ if err := ccCmd.Run(); err != nil {
+ return nil, fmt.Errorf("compiler error: %v", err)
+ }
+
+ bin, err := elf.Open(path)
+ if err != nil {
+ return nil, fmt.Errorf("cannot read ELF file %s: %v", path, err)
+ }
+
+ return bin, nil
+}
+
+func (t *target) writeBitFieldMasks(bin *elf.File, out io.Writer) error {
+ symbols, err := bin.Symbols()
+ if err != nil {
+ return fmt.Errorf("getting ELF symbols: %v", err)
+ }
+ var masksSym *elf.Symbol
+
+ for _, sym := range symbols {
+ if sym.Name == "masks" {
+ masksSym = &sym
+ }
+ }
+
+ if masksSym == nil {
+ return errors.New("could not find the 'masks' symbol in ELF symtab")
+ }
+
+ dataSection := bin.Section(".data")
+ if dataSection == nil {
+ return errors.New("ELF file has no .data section")
+ }
+
+ data, err := dataSection.Data()
+ if err != nil {
+ return fmt.Errorf("could not read .data section: %v\n", err)
+ }
+
+ var bo binary.ByteOrder
+ if t.BigEndian {
+ bo = binary.BigEndian
+ } else {
+ bo = binary.LittleEndian
+ }
+
+ // 64 bit masks of type uint64 are stored in the data section starting at masks.Value.
+ // Here we are running on AMD64, but these values may be big endian or little endian,
+ // depending on target architecture.
+ for i := uint64(0); i < 64; i++ {
+ off := masksSym.Value + i*8
+ // Define each mask in native by order, so as to match target endian.
+ fmt.Fprintf(out, "#define BITFIELD_MASK_%d %dULL\n", i, bo.Uint64(data[off:off+8]))
+ }
+
+ return nil
+}
+
+// makes the zsysnum_linux_$GOARCH.go file
+func (t *target) makeZSysnumFile() error {
+ zsysnumFile := fmt.Sprintf("zsysnum_linux_%s.go", t.GoArch)
+ unistdFile := filepath.Join(IncludeDir, "asm/unistd.h")
+
+ args := append(t.cFlags(), unistdFile)
+ return t.commandFormatOutput("gofmt", zsysnumFile, "mksysnum", args...)
+}
+
+// makes the zsyscall_linux_$GOARCH.go file
+func (t *target) makeZSyscallFile() error {
+ zsyscallFile := fmt.Sprintf("zsyscall_linux_%s.go", t.GoArch)
+ // Find the correct architecture syscall file (might end with x.go)
+ archSyscallFile := fmt.Sprintf("syscall_linux_%s.go", t.GoArch)
+ if _, err := os.Stat(archSyscallFile); os.IsNotExist(err) {
+ shortArch := strings.TrimSuffix(t.GoArch, "le")
+ archSyscallFile = fmt.Sprintf("syscall_linux_%sx.go", shortArch)
+ }
+
+ args := append(t.mksyscallFlags(), "-tags", "linux,"+t.GoArch,
+ "syscall_linux.go", archSyscallFile)
+ return t.commandFormatOutput("gofmt", zsyscallFile, "mksyscall", args...)
+}
+
+// makes the zerrors_linux_$GOARCH.go file
+func (t *target) makeZErrorsFile() error {
+ zerrorsFile := fmt.Sprintf("zerrors_linux_%s.go", t.GoArch)
+
+ return t.commandFormatOutput("gofmt", zerrorsFile, "./mkerrors.sh", t.cFlags()...)
+}
+
+// makes the ztypes_linux_$GOARCH.go file
+func (t *target) makeZTypesFile() error {
+ ztypesFile := fmt.Sprintf("ztypes_linux_%s.go", t.GoArch)
+
+ args := []string{"tool", "cgo", "-godefs", "--"}
+ args = append(args, t.cFlags()...)
+ args = append(args, "linux/types.go")
+ return t.commandFormatOutput("mkpost", ztypesFile, "go", args...)
+}
+
+// Flags that should be given to gcc and cgo for this target
+func (t *target) cFlags() []string {
+ // Compile statically to avoid cross-architecture dynamic linking.
+ flags := []string{"-Wall", "-Werror", "-static", "-I" + IncludeDir}
+
+ // Architecture-specific flags
+ if t.SignedChar {
+ flags = append(flags, "-fsigned-char")
+ }
+ if t.LinuxArch == "x86" {
+ flags = append(flags, fmt.Sprintf("-m%d", t.Bits))
+ }
+
+ return flags
+}
+
+// Flags that should be given to mksyscall for this target
+func (t *target) mksyscallFlags() (flags []string) {
+ if t.Bits == 32 {
+ if t.BigEndian {
+ flags = append(flags, "-b32")
+ } else {
+ flags = append(flags, "-l32")
+ }
+ }
+
+ // This flag means a 64-bit value should use (even, odd)-pair.
+ if t.GoArch == "arm" || (t.LinuxArch == "mips" && t.Bits == 32) {
+ flags = append(flags, "-arm")
+ }
+ return
+}
+
+// Merge all the generated files for Linux targets
+func mergeFiles() error {
+ // Setup environment variables
+ os.Setenv("GOOS", runtime.GOOS)
+ os.Setenv("GOARCH", runtime.GOARCH)
+
+ // Merge each of the four type of files
+ for _, ztyp := range []string{"zerrors", "zsyscall", "zsysnum", "ztypes"} {
+ cmd := makeCommand("go", "run", "mkmerge.go", "-out", fmt.Sprintf("%s_%s.go", ztyp, GOOS), fmt.Sprintf("%s_%s_*.go", ztyp, GOOS))
+ err := cmd.Run()
+ if err != nil {
+ return fmt.Errorf("could not merge %s files: %w", ztyp, err)
+ }
+ fmt.Printf("%s files merged\n", ztyp)
+ }
+
+ return nil
+}
+
+// generatePtracePair takes a pair of GOARCH values that can run each
+// other's binaries, such as 386 and amd64. It extracts the PtraceRegs
+// type for each one. It writes a new file defining the types
+// PtraceRegsArch1 and PtraceRegsArch2 and the corresponding functions
+// Ptrace{Get,Set}Regs{arch1,arch2}. This permits debugging the other
+// binary on a native system. 'archName' is the combined name of 'arch1'
+// and 'arch2', which is used in the file name.
+func generatePtracePair(arch1, arch2, archName string) error {
+ def1, err := ptraceDef(arch1)
+ if err != nil {
+ return err
+ }
+ def2, err := ptraceDef(arch2)
+ if err != nil {
+ return err
+ }
+ f, err := os.Create(fmt.Sprintf("zptrace_%s_linux.go", archName))
+ if err != nil {
+ return err
+ }
+ buf := bufio.NewWriter(f)
+ fmt.Fprintf(buf, "// Code generated by linux/mkall.go generatePtracePair(%q, %q). DO NOT EDIT.\n", arch1, arch2)
+ fmt.Fprintf(buf, "\n")
+ fmt.Fprintf(buf, "// +build linux\n")
+ fmt.Fprintf(buf, "// +build %s %s\n", arch1, arch2)
+ fmt.Fprintf(buf, "\n")
+ fmt.Fprintf(buf, "package unix\n")
+ fmt.Fprintf(buf, "\n")
+ fmt.Fprintf(buf, "%s\n", `import "unsafe"`)
+ fmt.Fprintf(buf, "\n")
+ writeOnePtrace(buf, arch1, def1)
+ fmt.Fprintf(buf, "\n")
+ writeOnePtrace(buf, arch2, def2)
+ if err := buf.Flush(); err != nil {
+ return err
+ }
+ if err := f.Close(); err != nil {
+ return err
+ }
+ return nil
+}
+
+// generatePtraceRegSet takes a GOARCH value to generate a file zptrace_linux_{arch}.go
+// containing functions PtraceGetRegSet{arch} and PtraceSetRegSet{arch}.
+func generatePtraceRegSet(arch string) error {
+ f, err := os.Create(fmt.Sprintf("zptrace_linux_%s.go", arch))
+ if err != nil {
+ return err
+ }
+ buf := bufio.NewWriter(f)
+ fmt.Fprintf(buf, "// Code generated by linux/mkall.go generatePtraceRegSet(%q). DO NOT EDIT.\n", arch)
+ fmt.Fprintf(buf, "\n")
+ fmt.Fprintf(buf, "package unix\n")
+ fmt.Fprintf(buf, "\n")
+ fmt.Fprintf(buf, "%s\n", `import "unsafe"`)
+ fmt.Fprintf(buf, "\n")
+ uarch := string(unicode.ToUpper(rune(arch[0]))) + arch[1:]
+ fmt.Fprintf(buf, "// PtraceGetRegSet%s fetches the registers used by %s binaries.\n", uarch, arch)
+ fmt.Fprintf(buf, "func PtraceGetRegSet%s(pid, addr int, regsout *PtraceRegs%s) error {\n", uarch, uarch)
+ fmt.Fprintf(buf, "\tiovec := Iovec{(*byte)(unsafe.Pointer(regsout)), uint64(unsafe.Sizeof(*regsout))}\n")
+ fmt.Fprintf(buf, "\treturn ptrace(PTRACE_GETREGSET, pid, uintptr(addr), uintptr(unsafe.Pointer(&iovec)))\n")
+ fmt.Fprintf(buf, "}\n")
+ fmt.Fprintf(buf, "\n")
+ fmt.Fprintf(buf, "// PtraceSetRegSet%s sets the registers used by %s binaries.\n", uarch, arch)
+ fmt.Fprintf(buf, "func PtraceSetRegSet%s(pid, addr int, regs *PtraceRegs%s) error {\n", uarch, uarch)
+ fmt.Fprintf(buf, "\tiovec := Iovec{(*byte)(unsafe.Pointer(regs)), uint64(unsafe.Sizeof(*regs))}\n")
+ fmt.Fprintf(buf, "\treturn ptrace(PTRACE_SETREGSET, pid, uintptr(addr), uintptr(unsafe.Pointer(&iovec)))\n")
+ fmt.Fprintf(buf, "}\n")
+ if err := buf.Flush(); err != nil {
+ return err
+ }
+ if err := f.Close(); err != nil {
+ return err
+ }
+ return nil
+}
+
+// ptraceDef returns the definition of PtraceRegs for arch.
+func ptraceDef(arch string) (string, error) {
+ filename := fmt.Sprintf("ztypes_linux_%s.go", arch)
+ data, err := ioutil.ReadFile(filename)
+ if err != nil {
+ return "", fmt.Errorf("reading %s: %v", filename, err)
+ }
+ start := bytes.Index(data, []byte("type PtraceRegs struct"))
+ if start < 0 {
+ return "", fmt.Errorf("%s: no definition of PtraceRegs", filename)
+ }
+ data = data[start:]
+ end := bytes.Index(data, []byte("\n}\n"))
+ if end < 0 {
+ return "", fmt.Errorf("%s: can't find end of PtraceRegs definition", filename)
+ }
+ return string(data[:end+2]), nil
+}
+
+// writeOnePtrace writes out the ptrace definitions for arch.
+func writeOnePtrace(w io.Writer, arch, def string) {
+ uarch := string(unicode.ToUpper(rune(arch[0]))) + arch[1:]
+ fmt.Fprintf(w, "// PtraceRegs%s is the registers used by %s binaries.\n", uarch, arch)
+ fmt.Fprintf(w, "%s\n", strings.Replace(def, "PtraceRegs", "PtraceRegs"+uarch, 1))
+ fmt.Fprintf(w, "\n")
+ fmt.Fprintf(w, "// PtraceGetRegs%s fetches the registers used by %s binaries.\n", uarch, arch)
+ fmt.Fprintf(w, "func PtraceGetRegs%s(pid int, regsout *PtraceRegs%s) error {\n", uarch, uarch)
+ fmt.Fprintf(w, "\treturn ptrace(PTRACE_GETREGS, pid, 0, uintptr(unsafe.Pointer(regsout)))\n")
+ fmt.Fprintf(w, "}\n")
+ fmt.Fprintf(w, "\n")
+ fmt.Fprintf(w, "// PtraceSetRegs%s sets the registers used by %s binaries.\n", uarch, arch)
+ fmt.Fprintf(w, "func PtraceSetRegs%s(pid int, regs *PtraceRegs%s) error {\n", uarch, uarch)
+ fmt.Fprintf(w, "\treturn ptrace(PTRACE_SETREGS, pid, 0, uintptr(unsafe.Pointer(regs)))\n")
+ fmt.Fprintf(w, "}\n")
+}
+
+// cCode is compiled for the target architecture, and the resulting data section is carved for
+// the statically initialized bit masks.
+const cCode = `
+// Bit fields are used in some system calls and other ABIs, but their memory layout is
+// implementation-defined [1]. Even with formal ABIs, bit fields are a source of subtle bugs [2].
+// Here we generate the offsets for all 64 bits in an uint64.
+// 1: http://en.cppreference.com/w/c/language/bit_field
+// 2: https://lwn.net/Articles/478657/
+
+#include <stdint.h>
+
+struct bitfield {
+ union {
+ uint64_t val;
+ struct {
+ uint64_t u64_bit_0 : 1;
+ uint64_t u64_bit_1 : 1;
+ uint64_t u64_bit_2 : 1;
+ uint64_t u64_bit_3 : 1;
+ uint64_t u64_bit_4 : 1;
+ uint64_t u64_bit_5 : 1;
+ uint64_t u64_bit_6 : 1;
+ uint64_t u64_bit_7 : 1;
+ uint64_t u64_bit_8 : 1;
+ uint64_t u64_bit_9 : 1;
+ uint64_t u64_bit_10 : 1;
+ uint64_t u64_bit_11 : 1;
+ uint64_t u64_bit_12 : 1;
+ uint64_t u64_bit_13 : 1;
+ uint64_t u64_bit_14 : 1;
+ uint64_t u64_bit_15 : 1;
+ uint64_t u64_bit_16 : 1;
+ uint64_t u64_bit_17 : 1;
+ uint64_t u64_bit_18 : 1;
+ uint64_t u64_bit_19 : 1;
+ uint64_t u64_bit_20 : 1;
+ uint64_t u64_bit_21 : 1;
+ uint64_t u64_bit_22 : 1;
+ uint64_t u64_bit_23 : 1;
+ uint64_t u64_bit_24 : 1;
+ uint64_t u64_bit_25 : 1;
+ uint64_t u64_bit_26 : 1;
+ uint64_t u64_bit_27 : 1;
+ uint64_t u64_bit_28 : 1;
+ uint64_t u64_bit_29 : 1;
+ uint64_t u64_bit_30 : 1;
+ uint64_t u64_bit_31 : 1;
+ uint64_t u64_bit_32 : 1;
+ uint64_t u64_bit_33 : 1;
+ uint64_t u64_bit_34 : 1;
+ uint64_t u64_bit_35 : 1;
+ uint64_t u64_bit_36 : 1;
+ uint64_t u64_bit_37 : 1;
+ uint64_t u64_bit_38 : 1;
+ uint64_t u64_bit_39 : 1;
+ uint64_t u64_bit_40 : 1;
+ uint64_t u64_bit_41 : 1;
+ uint64_t u64_bit_42 : 1;
+ uint64_t u64_bit_43 : 1;
+ uint64_t u64_bit_44 : 1;
+ uint64_t u64_bit_45 : 1;
+ uint64_t u64_bit_46 : 1;
+ uint64_t u64_bit_47 : 1;
+ uint64_t u64_bit_48 : 1;
+ uint64_t u64_bit_49 : 1;
+ uint64_t u64_bit_50 : 1;
+ uint64_t u64_bit_51 : 1;
+ uint64_t u64_bit_52 : 1;
+ uint64_t u64_bit_53 : 1;
+ uint64_t u64_bit_54 : 1;
+ uint64_t u64_bit_55 : 1;
+ uint64_t u64_bit_56 : 1;
+ uint64_t u64_bit_57 : 1;
+ uint64_t u64_bit_58 : 1;
+ uint64_t u64_bit_59 : 1;
+ uint64_t u64_bit_60 : 1;
+ uint64_t u64_bit_61 : 1;
+ uint64_t u64_bit_62 : 1;
+ uint64_t u64_bit_63 : 1;
+ };
+ };
+};
+
+struct bitfield masks[] = {
+ {.u64_bit_0 = 1},
+ {.u64_bit_1 = 1},
+ {.u64_bit_2 = 1},
+ {.u64_bit_3 = 1},
+ {.u64_bit_4 = 1},
+ {.u64_bit_5 = 1},
+ {.u64_bit_6 = 1},
+ {.u64_bit_7 = 1},
+ {.u64_bit_8 = 1},
+ {.u64_bit_9 = 1},
+ {.u64_bit_10 = 1},
+ {.u64_bit_11 = 1},
+ {.u64_bit_12 = 1},
+ {.u64_bit_13 = 1},
+ {.u64_bit_14 = 1},
+ {.u64_bit_15 = 1},
+ {.u64_bit_16 = 1},
+ {.u64_bit_17 = 1},
+ {.u64_bit_18 = 1},
+ {.u64_bit_19 = 1},
+ {.u64_bit_20 = 1},
+ {.u64_bit_21 = 1},
+ {.u64_bit_22 = 1},
+ {.u64_bit_23 = 1},
+ {.u64_bit_24 = 1},
+ {.u64_bit_25 = 1},
+ {.u64_bit_26 = 1},
+ {.u64_bit_27 = 1},
+ {.u64_bit_28 = 1},
+ {.u64_bit_29 = 1},
+ {.u64_bit_30 = 1},
+ {.u64_bit_31 = 1},
+ {.u64_bit_32 = 1},
+ {.u64_bit_33 = 1},
+ {.u64_bit_34 = 1},
+ {.u64_bit_35 = 1},
+ {.u64_bit_36 = 1},
+ {.u64_bit_37 = 1},
+ {.u64_bit_38 = 1},
+ {.u64_bit_39 = 1},
+ {.u64_bit_40 = 1},
+ {.u64_bit_41 = 1},
+ {.u64_bit_42 = 1},
+ {.u64_bit_43 = 1},
+ {.u64_bit_44 = 1},
+ {.u64_bit_45 = 1},
+ {.u64_bit_46 = 1},
+ {.u64_bit_47 = 1},
+ {.u64_bit_48 = 1},
+ {.u64_bit_49 = 1},
+ {.u64_bit_50 = 1},
+ {.u64_bit_51 = 1},
+ {.u64_bit_52 = 1},
+ {.u64_bit_53 = 1},
+ {.u64_bit_54 = 1},
+ {.u64_bit_55 = 1},
+ {.u64_bit_56 = 1},
+ {.u64_bit_57 = 1},
+ {.u64_bit_58 = 1},
+ {.u64_bit_59 = 1},
+ {.u64_bit_60 = 1},
+ {.u64_bit_61 = 1},
+ {.u64_bit_62 = 1},
+ {.u64_bit_63 = 1}
+};
+
+int main(int argc, char **argv) {
+ struct bitfield *mask_ptr = &masks[0];
+ return mask_ptr->val;
+}
+
+`
projects / dotfiles / .git / blobdiff