Revert "cmd/compile: enable Asan check for global variables"

This reverts CL 401775.

Reason for revert: broke build.

Change-Id: I4f6f2edff1e4afcf31cd90e26dacf303979eb10c
Reviewed-on: https://go-review.googlesource.com/c/go/+/403981
Reviewed-by: Daniel Martí <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Auto-Submit: Bryan Mills <[email protected]>
Run-TryBot: Bryan Mills <[email protected]>
Reviewed-by: Keith Randall <[email protected]>
Reviewed-by: Keith Randall <[email protected]>

misc/cgo/testsanitizers/asan_test.go

@@ -22,14 +22,6 @@ func TestASAN(t *testing.T) {
  if !aSanSupported(goos, goarch) {
  t.Skipf("skipping on %s/%s; -asan option is not supported.", goos, goarch)
  }
- // The current implementation is only compatible with the ASan library from version
- // v7 to v9 (See the description in src/runtime/asan/asan.go). Therefore, using the
- // -asan option must use a compatible version of ASan library, which requires that
- // the gcc version is not less than 7 and the clang version is not less than 9,
- // otherwise a segmentation fault will occur.
- if !compilerRequiredAsanVersion() {
- t.Skipf("skipping: too old version of compiler")
- }
 
  t.Parallel()
  requireOvercommit(t)

misc/cgo/testsanitizers/cc_test.go

@@ -184,16 +184,17 @@ func compilerVersion() (version, error) {
  var match [][]byte
  if bytes.HasPrefix(out, []byte("gcc")) {
  compiler.name = "gcc"
- cmd, err := cc("-v")
+
+ cmd, err := cc("-dumpversion")
  if err != nil {
  return err
  }
- out, err := cmd.CombinedOutput()
+ out, err := cmd.Output()
  if err != nil {
- // gcc, but does not support gcc's "-v" flag?!
+ // gcc, but does not support gcc's "-dumpversion" flag?!
  return err
  }
- gccRE := regexp.MustCompile(`gcc version (\d+)\.(\d+)`)
+ gccRE := regexp.MustCompile(`(\d+)\.(\d+)`)
  match = gccRE.FindSubmatch(out)
  } else {
  clangRE := regexp.MustCompile(`clang version (\d+)\.(\d+)`)
@@ -234,22 +235,6 @@ func compilerSupportsLocation() bool {
  }
 }
 
-// compilerRequiredAsanVersion reports whether the compiler is the version required by Asan.
-func compilerRequiredAsanVersion() bool {
- compiler, err := compilerVersion()
- if err != nil {
- return false
- }
- switch compiler.name {
- case "gcc":
- return compiler.major >= 7
- case "clang":
- return compiler.major >= 9
- default:
- return false
- }
-}
-
 type compilerCheck struct {
  once sync.Once
  err error

src/cmd/compile/internal/base/base.go

@@ -70,7 +70,6 @@ var NoInstrumentPkgs = []string{
  "runtime/msan",
  "runtime/asan",
  "internal/cpu",
- "buildcfg",
 }
 
 // Don't insert racefuncenter/racefuncexit into the following packages.

src/cmd/compile/internal/gc/obj.go

@@ -9,7 +9,6 @@ import (
  "cmd/compile/internal/ir"
  "cmd/compile/internal/noder"
  "cmd/compile/internal/objw"
- "cmd/compile/internal/pkginit"
  "cmd/compile/internal/reflectdata"
  "cmd/compile/internal/staticdata"
  "cmd/compile/internal/typecheck"
@@ -111,6 +110,7 @@ func dumpCompilerObj(bout *bio.Writer) {
 func dumpdata() {
  numExterns := len(typecheck.Target.Externs)
  numDecls := len(typecheck.Target.Decls)
+
  dumpglobls(typecheck.Target.Externs)
  reflectdata.CollectPTabs()
  numExports := len(typecheck.Target.Exports)
@@ -287,20 +287,7 @@ func ggloblnod(nam *ir.Name) {
  if nam.Type() != nil && !nam.Type().HasPointers() {
  flags |= obj.NOPTR
  }
- size := nam.Type().Size()
- linkname := nam.Sym().Linkname
- name := nam.Sym().Name
-
- // We've skipped linkname'd globals's instrument, so we can skip them here as well.
- if base.Flag.ASan && linkname == "" && pkginit.InstrumentGlobalsMap[name] != nil {
- // Write the new size of instrumented global variables that have
- // trailing redzones into object file.
- rzSize := pkginit.GetRedzoneSizeForGlobal(size)
- sizeWithRZ := rzSize + size
- base.Ctxt.Globl(s, sizeWithRZ, flags)
- } else {
- base.Ctxt.Globl(s, size, flags)
- }
+ base.Ctxt.Globl(s, nam.Type().Size(), flags)
  if nam.LibfuzzerExtraCounter() {
  s.Type = objabi.SLIBFUZZER_EXTRA_COUNTER
  }

src/cmd/compile/internal/noder/noder.go

@@ -442,7 +442,7 @@ func parseGoEmbed(args string) ([]string, error) {
 // the name, normally "pkg.init", is altered to "pkg.init.0".
 var renameinitgen int
 
-func Renameinit() *types.Sym {
+func renameinit() *types.Sym {
  s := typecheck.LookupNum("init.", renameinitgen)
  renameinitgen++
  return s

src/cmd/compile/internal/noder/object.go

@@ -104,7 +104,7 @@ func (g *irgen) obj(obj types2.Object) *ir.Name {
  var typ *types.Type
  if recv := sig.Recv(); recv == nil {
  if obj.Name() == "init" {
- sym = Renameinit()
+ sym = renameinit()
  } else {
  sym = g.sym(obj)
  }

src/cmd/compile/internal/noder/reader.go

@@ -645,7 +645,7 @@ func (pr *pkgReader) objIdx(idx int, implicits, explicits []*types.Type) ir.Node
 
  case pkgbits.ObjFunc:
  if sym.Name == "init" {
- sym = Renameinit()
+ sym = renameinit()
  }
  name := do(ir.ONAME, true)
  setType(name, r.signature(sym.Pkg, nil))

src/cmd/compile/internal/pkginit/init.go

@@ -7,7 +7,6 @@ package pkginit
 import (
  "cmd/compile/internal/base"
  "cmd/compile/internal/ir"
- "cmd/compile/internal/noder"
  "cmd/compile/internal/objw"
  "cmd/compile/internal/staticinit"
  "cmd/compile/internal/typecheck"
@@ -84,58 +83,6 @@ func Task() *ir.Name {
  }
  deps = append(deps, n.(*ir.Name).Linksym())
  }
- if base.Flag.ASan {
- // Make an initialization function to call runtime.asanregisterglobals to register an
- // array of instrumented global variables when -asan is enabled. An instrumented global
- // variable is described by a structure.
- // See the _asan_global structure declared in src/runtime/asan/asan.go.
- //
- // func init {
- // var globals []_asan_global {...}
- // asanregisterglobals(&globals[0], len(globals))
- // }
- for _, n := range typecheck.Target.Externs {
- if canInstrumentGlobal(n) {
- name := n.Sym().Name
- InstrumentGlobalsMap[name] = n
- InstrumentGlobalsSlice = append(InstrumentGlobalsSlice, n)
- }
- }
- ni := len(InstrumentGlobalsMap)
- if ni != 0 {
- // Make an init._ function.
- base.Pos = base.AutogeneratedPos
- typecheck.DeclContext = ir.PEXTERN
- name := noder.Renameinit()
- fnInit := typecheck.DeclFunc(name, ir.NewFuncType(base.Pos, nil, nil, nil))
-
- // Get an array of intrumented global variables.
- globals := instrumentGlobals(fnInit)
-
- // Call runtime.asanregisterglobals function to poison redzones.
- // runtime.asanregisterglobals(unsafe.Pointer(&globals[0]), ni)
- asanf := typecheck.NewName(ir.Pkgs.Runtime.Lookup("asanregisterglobals"))
- ir.MarkFunc(asanf)
- asanf.SetType(types.NewSignature(types.NoPkg, nil, nil, []*types.Field{
- types.NewField(base.Pos, nil, types.Types[types.TUNSAFEPTR]),
- types.NewField(base.Pos, nil, types.Types[types.TUINTPTR]),
- }, nil))
- asancall := ir.NewCallExpr(base.Pos, ir.OCALL, asanf, nil)
- asancall.Args.Append(typecheck.ConvNop(typecheck.NodAddr(
- ir.NewIndexExpr(base.Pos, globals, ir.NewInt(0))), types.Types[types.TUNSAFEPTR]))
- asancall.Args.Append(typecheck.ConvNop(ir.NewInt(int64(ni)), types.Types[types.TUINTPTR]))
-
- fnInit.Body.Append(asancall)
- typecheck.FinishFuncBody()
- typecheck.Func(fnInit)
- ir.CurFunc = fnInit
- typecheck.Stmts(fnInit.Body)
- ir.CurFunc = nil
-
- typecheck.Target.Decls = append(typecheck.Target.Decls, fnInit)
- typecheck.Target.Inits = append(typecheck.Target.Inits, fnInit)
- }
- }
 
  // Record user init functions.
  for _, fn := range typecheck.Target.Inits {