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-rw-r--r--src/cmd/compile/internal/base/base.go1
-rw-r--r--src/cmd/compile/internal/gc/obj.go17
-rw-r--r--src/cmd/compile/internal/noder/noder.go2
-rw-r--r--src/cmd/compile/internal/noder/object.go2
-rw-r--r--src/cmd/compile/internal/noder/reader.go2
-rw-r--r--src/cmd/compile/internal/pkginit/init.go53
-rw-r--r--src/cmd/compile/internal/pkginit/initAsanGlobals.go241
7 files changed, 313 insertions, 5 deletions
diff --git a/src/cmd/compile/internal/base/base.go b/src/cmd/compile/internal/base/base.go
index 39ce8e66f7..5e1493e275 100644
--- a/src/cmd/compile/internal/base/base.go
+++ b/src/cmd/compile/internal/base/base.go
@@ -70,6 +70,7 @@ var NoInstrumentPkgs = []string{
"runtime/msan",
"runtime/asan",
"internal/cpu",
+ "buildcfg",
}
// Don't insert racefuncenter/racefuncexit into the following packages.
diff --git a/src/cmd/compile/internal/gc/obj.go b/src/cmd/compile/internal/gc/obj.go
index fe8b6e9d45..fea2df85e5 100644
--- a/src/cmd/compile/internal/gc/obj.go
+++ b/src/cmd/compile/internal/gc/obj.go
@@ -9,6 +9,7 @@ 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"
@@ -110,7 +111,6 @@ 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)
@@ -287,7 +287,20 @@ func ggloblnod(nam *ir.Name) {
if nam.Type() != nil && !nam.Type().HasPointers() {
flags |= obj.NOPTR
}
- base.Ctxt.Globl(s, nam.Type().Size(), flags)
+ 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)
+ }
if nam.LibfuzzerExtraCounter() {
s.Type = objabi.SLIBFUZZER_EXTRA_COUNTER
}
diff --git a/src/cmd/compile/internal/noder/noder.go b/src/cmd/compile/internal/noder/noder.go
index 9a42b5afd1..c4c2db5f78 100644
--- a/src/cmd/compile/internal/noder/noder.go
+++ b/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
diff --git a/src/cmd/compile/internal/noder/object.go b/src/cmd/compile/internal/noder/object.go
index e8dbaac161..ee9e0e2680 100644
--- a/src/cmd/compile/internal/noder/object.go
+++ b/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)
}
diff --git a/src/cmd/compile/internal/noder/reader.go b/src/cmd/compile/internal/noder/reader.go
index 1350c22467..10861717f3 100644
--- a/src/cmd/compile/internal/noder/reader.go
+++ b/src/cmd/compile/internal/noder/reader.go
@@ -643,7 +643,7 @@ 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))
diff --git a/src/cmd/compile/internal/pkginit/init.go b/src/cmd/compile/internal/pkginit/init.go
index 32e95bedc2..d94482a962 100644
--- a/src/cmd/compile/internal/pkginit/init.go
+++ b/src/cmd/compile/internal/pkginit/init.go
@@ -7,6 +7,7 @@ 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"
@@ -83,6 +84,58 @@ 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 {
diff --git a/src/cmd/compile/internal/pkginit/initAsanGlobals.go b/src/cmd/compile/internal/pkginit/initAsanGlobals.go
new file mode 100644
index 0000000000..7276791d6e
--- /dev/null
+++ b/src/cmd/compile/internal/pkginit/initAsanGlobals.go
@@ -0,0 +1,241 @@
+// Copyright 2022 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 pkginit
+
+import (
+ "strings"
+
+ "cmd/compile/internal/base"
+ "cmd/compile/internal/ir"
+ "cmd/compile/internal/typecheck"
+ "cmd/compile/internal/types"
+ "cmd/internal/src"
+)
+
+// instrumentGlobals declares a global array of _asan_global structures and initializes it.
+func instrumentGlobals(fn *ir.Func) *ir.Name {
+ asanGlobalStruct, asanLocationStruct, defStringstruct := createtypes()
+ lname := typecheck.Lookup
+ tconv := typecheck.ConvNop
+ // Make a global array of asanGlobalStruct type.
+ // var asanglobals []asanGlobalStruct
+ arraytype := types.NewArray(asanGlobalStruct, int64(len(InstrumentGlobalsMap)))
+ symG := lname(".asanglobals")
+ globals := typecheck.NewName(symG)
+ globals.SetType(arraytype)
+ globals.Class = ir.PEXTERN
+ symG.Def = globals
+ typecheck.Target.Externs = append(typecheck.Target.Externs, globals)
+ // Make a global array of asanLocationStruct type.
+ // var asanL []asanLocationStruct
+ arraytype = types.NewArray(asanLocationStruct, int64(len(InstrumentGlobalsMap)))
+ symL := lname(".asanL")
+ asanlocation := typecheck.NewName(symL)
+ asanlocation.SetType(arraytype)
+ asanlocation.Class = ir.PEXTERN
+ symL.Def = asanlocation
+ typecheck.Target.Externs = append(typecheck.Target.Externs, asanlocation)
+ // Make three global string variables to pass the global name and module name
+ // and the name of the source file that defines it.
+ // var asanName string
+ // var asanModulename string
+ // var asanFilename string
+ symL = lname(".asanName")
+ asanName := typecheck.NewName(symL)
+ asanName.SetType(types.Types[types.TSTRING])
+ asanName.Class = ir.PEXTERN
+ symL.Def = asanName
+ typecheck.Target.Externs = append(typecheck.Target.Externs, asanName)
+
+ symL = lname(".asanModulename")
+ asanModulename := typecheck.NewName(symL)
+ asanModulename.SetType(types.Types[types.TSTRING])
+ asanModulename.Class = ir.PEXTERN
+ symL.Def = asanModulename
+ typecheck.Target.Externs = append(typecheck.Target.Externs, asanModulename)
+
+ symL = lname(".asanFilename")
+ asanFilename := typecheck.NewName(symL)
+ asanFilename.SetType(types.Types[types.TSTRING])
+ asanFilename.Class = ir.PEXTERN
+ symL.Def = asanFilename
+ typecheck.Target.Externs = append(typecheck.Target.Externs, asanFilename)
+
+ var init ir.Nodes
+ var c ir.Node
+ // globals[i].odrIndicator = 0 is the default, no need to set it explicitly here.
+ for i, n := range InstrumentGlobalsSlice {
+ setField := func(f string, val ir.Node, i int) {
+ r := ir.NewAssignStmt(base.Pos, ir.NewSelectorExpr(base.Pos, ir.ODOT,
+ ir.NewIndexExpr(base.Pos, globals, ir.NewInt(int64(i))), lname(f)), val)
+ init.Append(typecheck.Stmt(r))
+ }
+ // globals[i].beg = uintptr(unsafe.Pointer(&n))
+ c = tconv(typecheck.NodAddr(n), types.Types[types.TUNSAFEPTR])
+ c = tconv(c, types.Types[types.TUINTPTR])
+ setField("beg", c, i)
+ // Assign globals[i].size.
+ g := n.(*ir.Name)
+ size := g.Type().Size()
+ c = tconv(ir.NewInt(size), types.Types[types.TUINTPTR])
+ setField("size", c, i)
+ // Assign globals[i].sizeWithRedzone.
+ rzSize := GetRedzoneSizeForGlobal(size)
+ sizeWithRz := rzSize + size
+ c = tconv(ir.NewInt(sizeWithRz), types.Types[types.TUINTPTR])
+ setField("sizeWithRedzone", c, i)
+ // The C string type is terminated by a null charactor "\0", Go should use three-digit
+ // octal "\000" or two-digit hexadecimal "\x00" to create null terminated string.
+ // asanName = symbol's linkname + "\000"
+ // globals[i].name = (*defString)(unsafe.Pointer(&asanName)).data
+ name := g.Linksym().Name
+ init.Append(typecheck.Stmt(ir.NewAssignStmt(base.Pos, asanName, ir.NewString(name+"\000"))))
+ c = tconv(typecheck.NodAddr(asanName), types.Types[types.TUNSAFEPTR])
+ c = tconv(c, types.NewPtr(defStringstruct))
+ c = ir.NewSelectorExpr(base.Pos, ir.ODOT, c, lname("data"))
+ setField("name", c, i)
+
+ // Set the name of package being compiled as a unique identifier of a module.
+ // asanModulename = pkgName + "\000"
+ init.Append(typecheck.Stmt(ir.NewAssignStmt(base.Pos, asanModulename, ir.NewString(types.LocalPkg.Name+"\000"))))
+ c = tconv(typecheck.NodAddr(asanModulename), types.Types[types.TUNSAFEPTR])
+ c = tconv(c, types.NewPtr(defStringstruct))
+ c = ir.NewSelectorExpr(base.Pos, ir.ODOT, c, lname("data"))
+ setField("moduleName", c, i)
+ // Assign asanL[i].filename, asanL[i].line, asanL[i].column
+ // and assign globals[i].location = uintptr(unsafe.Pointer(&asanL[i]))
+ asanLi := ir.NewIndexExpr(base.Pos, asanlocation, ir.NewInt(int64(i)))
+ filename := ir.NewString(base.Ctxt.PosTable.Pos(n.Pos()).Filename() + "\000")
+ init.Append(typecheck.Stmt(ir.NewAssignStmt(base.Pos, asanFilename, filename)))
+ c = tconv(typecheck.NodAddr(asanFilename), types.Types[types.TUNSAFEPTR])
+ c = tconv(c, types.NewPtr(defStringstruct))
+ c = ir.NewSelectorExpr(base.Pos, ir.ODOT, c, lname("data"))
+ init.Append(typecheck.Stmt(ir.NewAssignStmt(base.Pos, ir.NewSelectorExpr(base.Pos, ir.ODOT, asanLi, lname("filename")), c)))
+ line := ir.NewInt(int64(n.Pos().Line()))
+ init.Append(typecheck.Stmt(ir.NewAssignStmt(base.Pos, ir.NewSelectorExpr(base.Pos, ir.ODOT, asanLi, lname("line")), line)))
+ col := ir.NewInt(int64(n.Pos().Col()))
+ init.Append(typecheck.Stmt(ir.NewAssignStmt(base.Pos, ir.NewSelectorExpr(base.Pos, ir.ODOT, asanLi, lname("column")), col)))
+ c = tconv(typecheck.NodAddr(asanLi), types.Types[types.TUNSAFEPTR])
+ c = tconv(c, types.Types[types.TUINTPTR])
+ setField("sourceLocation", c, i)
+ }
+ fn.Body.Append(init...)
+ return globals
+}
+
+// createtypes creates the asanGlobal, asanLocation and defString struct type.
+// Go compiler does not refer to the C types, we represent the struct field
+// by a uintptr, then use type conversion to make copies of the data.
+// E.g., (*defString)(asanGlobal.name).data to C string.
+//
+// Keep in sync with src/runtime/asan/asan.go.
+// type asanGlobal struct {
+// beg uintptr
+// size uintptr
+// size_with_redzone uintptr
+// name uintptr
+// moduleName uintptr
+// hasDynamicInit uintptr
+// sourceLocation uintptr
+// odrIndicator uintptr
+// }
+//
+// type asanLocation struct {
+// filename uintptr
+// line int32
+// column int32
+// }
+//
+// defString is synthesized struct type meant to capture the underlying
+// implementations of string.
+// type defString struct {
+// data uintptr
+// len uintptr
+// }
+
+func createtypes() (*types.Type, *types.Type, *types.Type) {
+ up := types.Types[types.TUINTPTR]
+ i32 := types.Types[types.TINT32]
+ fname := typecheck.Lookup
+ nxp := src.NoXPos
+ nfield := types.NewField
+ asanGlobal := types.NewStruct(types.NoPkg, []*types.Field{
+ nfield(nxp, fname("beg"), up),
+ nfield(nxp, fname("size"), up),
+ nfield(nxp, fname("sizeWithRedzone"), up),
+ nfield(nxp, fname("name"), up),
+ nfield(nxp, fname("moduleName"), up),
+ nfield(nxp, fname("hasDynamicInit"), up),
+ nfield(nxp, fname("sourceLocation"), up),
+ nfield(nxp, fname("odrIndicator"), up),
+ })
+ types.CalcSize(asanGlobal)
+
+ asanLocation := types.NewStruct(types.NoPkg, []*types.Field{
+ nfield(nxp, fname("filename"), up),
+ nfield(nxp, fname("line"), i32),
+ nfield(nxp, fname("column"), i32),
+ })
+ types.CalcSize(asanLocation)
+
+ defString := types.NewStruct(types.NoPkg, []*types.Field{
+ types.NewField(nxp, fname("data"), up),
+ types.NewField(nxp, fname("len"), up),
+ })
+ types.CalcSize(defString)
+
+ return asanGlobal, asanLocation, defString
+}
+
+// Calculate redzone for globals.
+func GetRedzoneSizeForGlobal(size int64) int64 {
+ maxRZ := int64(1 << 18)
+ minRZ := int64(32)
+ redZone := (size / minRZ / 4) * minRZ
+ switch {
+ case redZone > maxRZ:
+ redZone = maxRZ
+ case redZone < minRZ:
+ redZone = minRZ
+ }
+ // Round up to multiple of minRZ.
+ if size%minRZ != 0 {
+ redZone += minRZ - (size % minRZ)
+ }
+ return redZone
+}
+
+// InstrumentGlobalsMap contains only package-local (and unlinknamed from somewhere else)
+// globals.
+// And the key is the object name. For example, in package p, a global foo would be in this
+// map as "foo".
+// Consider range over maps is nondeterministic, make a slice to hold all the values in the
+// InstrumentGlobalsMap and iterate over the InstrumentGlobalsSlice.
+var InstrumentGlobalsMap = make(map[string]ir.Node)
+var InstrumentGlobalsSlice = make([]ir.Node, 0, 0)
+
+func canInstrumentGlobal(g ir.Node) bool {
+ if g.Op() != ir.ONAME {
+ return false
+ }
+ n := g.(*ir.Name)
+ if n.Class == ir.PFUNC {
+ return false
+ }
+ if n.Sym().Pkg != types.LocalPkg {
+ return false
+ }
+ // Do not instrument any _cgo_ related global variables, because they are declared in C code.
+ if strings.Contains(n.Sym().Name, "cgo") {
+ return false
+ }
+
+ // Do not instrument globals that are linknamed, because their home package will do the work.
+ if n.Sym().Linkname != "" {
+ return false
+ }
+
+ return true
+}
generated by cgit v1.3-6-g1900 (git 2.53.0) at 2026-04-17 19:25:42 +0000