// Copyright 2016 Google Inc. All rights reserved. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. package cc import ( "fmt" "io" "sort" "strings" "sync" "android/soong/android" "android/soong/cc/config" ) var ( // Any C flags added by sanitizer which libTooling tools may not // understand also need to be added to ClangLibToolingUnknownCflags in // cc/config/clang.go asanCflags = []string{"-fno-omit-frame-pointer"} asanLdflags = []string{"-Wl,-u,__asan_preinit"} asanLibs = []string{"libasan"} cfiCflags = []string{"-flto", "-fsanitize-cfi-cross-dso", "-fsanitize-blacklist=external/compiler-rt/lib/cfi/cfi_blacklist.txt"} cfiLdflags = []string{"-flto", "-fsanitize-cfi-cross-dso", "-fsanitize=cfi", "-Wl,-plugin-opt,O1"} cfiExportsMapPath = "build/soong/cc/config/cfi_exports.map" cfiStaticLibsMutex sync.Mutex intOverflowCflags = []string{"-fsanitize-blacklist=build/soong/cc/config/integer_overflow_blacklist.txt"} minimalRuntimeFlags = []string{"-fsanitize-minimal-runtime", "-fno-sanitize-trap=integer", "-fno-sanitize-recover=integer"} ) type sanitizerType int func boolPtr(v bool) *bool { if v { return &v } else { return nil } } const ( asan sanitizerType = iota + 1 tsan intOverflow cfi ) func (t sanitizerType) String() string { switch t { case asan: return "asan" case tsan: return "tsan" case intOverflow: return "intOverflow" case cfi: return "cfi" default: panic(fmt.Errorf("unknown sanitizerType %d", t)) } } type SanitizeProperties struct { // enable AddressSanitizer, ThreadSanitizer, or UndefinedBehaviorSanitizer Sanitize struct { Never *bool `android:"arch_variant"` // main sanitizers Address *bool `android:"arch_variant"` Thread *bool `android:"arch_variant"` // local sanitizers Undefined *bool `android:"arch_variant"` All_undefined *bool `android:"arch_variant"` Misc_undefined []string `android:"arch_variant"` Coverage *bool `android:"arch_variant"` Safestack *bool `android:"arch_variant"` Cfi *bool `android:"arch_variant"` Integer_overflow *bool `android:"arch_variant"` // Sanitizers to run in the diagnostic mode (as opposed to the release mode). // Replaces abort() on error with a human-readable error message. // Address and Thread sanitizers always run in diagnostic mode. Diag struct { Undefined *bool `android:"arch_variant"` Cfi *bool `android:"arch_variant"` Integer_overflow *bool `android:"arch_variant"` Misc_undefined []string `android:"arch_variant"` } // value to pass to -fsanitize-recover= Recover []string // value to pass to -fsanitize-blacklist Blacklist *string } `android:"arch_variant"` SanitizerEnabled bool `blueprint:"mutated"` SanitizeDep bool `blueprint:"mutated"` MinimalRuntimeDep bool `blueprint:"mutated"` InSanitizerDir bool `blueprint:"mutated"` } type sanitize struct { Properties SanitizeProperties runtimeLibrary string androidMkRuntimeLibrary string } func init() { android.RegisterMakeVarsProvider(pctx, cfiMakeVarsProvider) } func (sanitize *sanitize) props() []interface{} { return []interface{}{&sanitize.Properties} } func (sanitize *sanitize) begin(ctx BaseModuleContext) { s := &sanitize.Properties.Sanitize // Don't apply sanitizers to NDK code. if ctx.useSdk() { s.Never = BoolPtr(true) } // Never always wins. if Bool(s.Never) { return } var globalSanitizers []string var globalSanitizersDiag []string if ctx.clang() { if ctx.Host() { globalSanitizers = ctx.Config().SanitizeHost() } else { arches := ctx.Config().SanitizeDeviceArch() if len(arches) == 0 || inList(ctx.Arch().ArchType.Name, arches) { globalSanitizers = ctx.Config().SanitizeDevice() globalSanitizersDiag = ctx.Config().SanitizeDeviceDiag() } } } if len(globalSanitizers) > 0 { var found bool if found, globalSanitizers = removeFromList("undefined", globalSanitizers); found && s.All_undefined == nil { s.All_undefined = boolPtr(true) } if found, globalSanitizers = removeFromList("default-ub", globalSanitizers); found && s.Undefined == nil { s.Undefined = boolPtr(true) } if found, globalSanitizers = removeFromList("address", globalSanitizers); found { if s.Address == nil { s.Address = boolPtr(true) } else if *s.Address == false { // Coverage w/o address is an error. If globalSanitizers includes both, and the module // disables address, then disable coverage as well. _, globalSanitizers = removeFromList("coverage", globalSanitizers) } } if found, globalSanitizers = removeFromList("thread", globalSanitizers); found && s.Thread == nil { s.Thread = boolPtr(true) } if found, globalSanitizers = removeFromList("coverage", globalSanitizers); found && s.Coverage == nil { s.Coverage = boolPtr(true) } if found, globalSanitizers = removeFromList("safe-stack", globalSanitizers); found && s.Safestack == nil { s.Safestack = boolPtr(true) } if found, globalSanitizers = removeFromList("cfi", globalSanitizers); found && s.Cfi == nil { if !ctx.Config().CFIDisabledForPath(ctx.ModuleDir()) { s.Cfi = boolPtr(true) } } if found, globalSanitizers = removeFromList("integer_overflow", globalSanitizers); found && s.Integer_overflow == nil { if !ctx.Config().IntegerOverflowDisabledForPath(ctx.ModuleDir()) { s.Integer_overflow = boolPtr(true) } } if len(globalSanitizers) > 0 { ctx.ModuleErrorf("unknown global sanitizer option %s", globalSanitizers[0]) } if found, globalSanitizersDiag = removeFromList("integer_overflow", globalSanitizersDiag); found && s.Diag.Integer_overflow == nil && Bool(s.Integer_overflow) { s.Diag.Integer_overflow = boolPtr(true) } if found, globalSanitizersDiag = removeFromList("cfi", globalSanitizersDiag); found && s.Diag.Cfi == nil && Bool(s.Cfi) { s.Diag.Cfi = boolPtr(true) } if len(globalSanitizersDiag) > 0 { ctx.ModuleErrorf("unknown global sanitizer diagnostics option %s", globalSanitizersDiag[0]) } } // Enable CFI for all components in the include paths if s.Cfi == nil && ctx.Config().CFIEnabledForPath(ctx.ModuleDir()) { s.Cfi = boolPtr(true) if inList("cfi", ctx.Config().SanitizeDeviceDiag()) { s.Diag.Cfi = boolPtr(true) } } // CFI needs gold linker, and mips toolchain does not have one. if !ctx.Config().EnableCFI() || ctx.Arch().ArchType == android.Mips || ctx.Arch().ArchType == android.Mips64 { s.Cfi = nil s.Diag.Cfi = nil } // Also disable CFI for arm32 until b/35157333 is fixed. if ctx.Arch().ArchType == android.Arm { s.Cfi = nil s.Diag.Cfi = nil } // Also disable CFI if ASAN is enabled. if Bool(s.Address) { s.Cfi = nil s.Diag.Cfi = nil } // Also disable CFI for host builds. if ctx.Host() { s.Cfi = nil s.Diag.Cfi = nil } if ctx.staticBinary() { s.Address = nil s.Coverage = nil s.Thread = nil } if Bool(s.All_undefined) { s.Undefined = nil } if !ctx.toolchain().Is64Bit() { // TSAN and SafeStack are not supported on 32-bit architectures s.Thread = nil s.Safestack = nil // TODO(ccross): error for compile_multilib = "32"? } if ctx.Os() != android.Windows && (Bool(s.All_undefined) || Bool(s.Undefined) || Bool(s.Address) || Bool(s.Thread) || Bool(s.Coverage) || Bool(s.Safestack) || Bool(s.Cfi) || Bool(s.Integer_overflow) || len(s.Misc_undefined) > 0) { sanitize.Properties.SanitizerEnabled = true } if Bool(s.Coverage) { if !Bool(s.Address) { ctx.ModuleErrorf(`Use of "coverage" also requires "address"`) } } } func (sanitize *sanitize) deps(ctx BaseModuleContext, deps Deps) Deps { if !sanitize.Properties.SanitizerEnabled { // || c.static() { return deps } if ctx.Device() { if Bool(sanitize.Properties.Sanitize.Address) { deps.StaticLibs = append(deps.StaticLibs, asanLibs...) } } return deps } func (sanitize *sanitize) flags(ctx ModuleContext, flags Flags) Flags { minimalRuntimePath := "${config.ClangAsanLibDir}/" + config.UndefinedBehaviorSanitizerMinimalRuntimeLibrary(ctx.toolchain()) + ".a" if ctx.Device() && sanitize.Properties.MinimalRuntimeDep { flags.LdFlags = append(flags.LdFlags, minimalRuntimePath) } if !sanitize.Properties.SanitizerEnabled { return flags } if !ctx.clang() { ctx.ModuleErrorf("Use of sanitizers requires clang") } var sanitizers []string var diagSanitizers []string if Bool(sanitize.Properties.Sanitize.All_undefined) { sanitizers = append(sanitizers, "undefined") } else { if Bool(sanitize.Properties.Sanitize.Undefined) { sanitizers = append(sanitizers, "bool", "integer-divide-by-zero", "return", "returns-nonnull-attribute", "shift-exponent", "unreachable", "vla-bound", // TODO(danalbert): The following checks currently have compiler performance issues. //"alignment", //"bounds", //"enum", //"float-cast-overflow", //"float-divide-by-zero", //"nonnull-attribute", //"null", //"shift-base", //"signed-integer-overflow", // TODO(danalbert): Fix UB in libc++'s __tree so we can turn this on. // https://llvm.org/PR19302 // http://reviews.llvm.org/D6974 // "object-size", ) } sanitizers = append(sanitizers, sanitize.Properties.Sanitize.Misc_undefined...) } if Bool(sanitize.Properties.Sanitize.Diag.Undefined) { diagSanitizers = append(diagSanitizers, "undefined") } diagSanitizers = append(diagSanitizers, sanitize.Properties.Sanitize.Diag.Misc_undefined...) if Bool(sanitize.Properties.Sanitize.Address) { if ctx.Arch().ArchType == android.Arm { // Frame pointer based unwinder in ASan requires ARM frame setup. // TODO: put in flags? flags.RequiredInstructionSet = "arm" } flags.CFlags = append(flags.CFlags, asanCflags...) flags.LdFlags = append(flags.LdFlags, asanLdflags...) if ctx.Host() { // -nodefaultlibs (provided with libc++) prevents the driver from linking // libraries needed with -fsanitize=address. http://b/18650275 (WAI) flags.LdFlags = append(flags.LdFlags, "-Wl,--no-as-needed") } else { flags.CFlags = append(flags.CFlags, "-mllvm", "-asan-globals=0") flags.DynamicLinker = "/system/bin/linker_asan" if flags.Toolchain.Is64Bit() { flags.DynamicLinker += "64" } } sanitizers = append(sanitizers, "address") diagSanitizers = append(diagSanitizers, "address") } if Bool(sanitize.Properties.Sanitize.Thread) { sanitizers = append(sanitizers, "thread") } if Bool(sanitize.Properties.Sanitize.Coverage) { flags.CFlags = append(flags.CFlags, "-fsanitize-coverage=trace-pc-guard,indirect-calls,trace-cmp") } if Bool(sanitize.Properties.Sanitize.Safestack) { sanitizers = append(sanitizers, "safe-stack") } if Bool(sanitize.Properties.Sanitize.Cfi) { if ctx.Arch().ArchType == android.Arm { // __cfi_check needs to be built as Thumb (see the code in linker_cfi.cpp). LLVM is not set up // to do this on a function basis, so force Thumb on the entire module. flags.RequiredInstructionSet = "thumb" } sanitizers = append(sanitizers, "cfi") flags.CFlags = append(flags.CFlags, cfiCflags...) // Only append the default visibility flag if -fvisibility has not already been set // to hidden. if !inList("-fvisibility=hidden", flags.CFlags) { flags.CFlags = append(flags.CFlags, "-fvisibility=default") } flags.LdFlags = append(flags.LdFlags, cfiLdflags...) if ctx.Device() { // Work around a bug in Clang. The CFI sanitizer requires LTO, and when // LTO is enabled, the Clang driver fails to enable emutls for Android. // See b/72706604 or https://github.com/android-ndk/ndk/issues/498. flags.LdFlags = append(flags.LdFlags, "-Wl,-plugin-opt,-emulated-tls") } flags.ArGoldPlugin = true if Bool(sanitize.Properties.Sanitize.Diag.Cfi) { diagSanitizers = append(diagSanitizers, "cfi") } if ctx.staticBinary() { _, flags.CFlags = removeFromList("-fsanitize-cfi-cross-dso", flags.CFlags) _, flags.LdFlags = removeFromList("-fsanitize-cfi-cross-dso", flags.LdFlags) } } if Bool(sanitize.Properties.Sanitize.Integer_overflow) { if !ctx.static() { sanitizers = append(sanitizers, "unsigned-integer-overflow") sanitizers = append(sanitizers, "signed-integer-overflow") flags.CFlags = append(flags.CFlags, intOverflowCflags...) if Bool(sanitize.Properties.Sanitize.Diag.Integer_overflow) { diagSanitizers = append(diagSanitizers, "unsigned-integer-overflow") diagSanitizers = append(diagSanitizers, "signed-integer-overflow") } } } if len(sanitizers) > 0 { sanitizeArg := "-fsanitize=" + strings.Join(sanitizers, ",") flags.CFlags = append(flags.CFlags, sanitizeArg) if ctx.Host() { flags.CFlags = append(flags.CFlags, "-fno-sanitize-recover=all") flags.LdFlags = append(flags.LdFlags, sanitizeArg) // Host sanitizers only link symbols in the final executable, so // there will always be undefined symbols in intermediate libraries. _, flags.LdFlags = removeFromList("-Wl,--no-undefined", flags.LdFlags) } else { flags.CFlags = append(flags.CFlags, "-fsanitize-trap=all", "-ftrap-function=abort") if enableMinimalRuntime(sanitize) { flags.CFlags = append(flags.CFlags, strings.Join(minimalRuntimeFlags, " ")) flags.libFlags = append([]string{minimalRuntimePath}, flags.libFlags...) } } } if len(diagSanitizers) > 0 { flags.CFlags = append(flags.CFlags, "-fno-sanitize-trap="+strings.Join(diagSanitizers, ",")) } // FIXME: enable RTTI if diag + (cfi or vptr) if sanitize.Properties.Sanitize.Recover != nil { flags.CFlags = append(flags.CFlags, "-fsanitize-recover="+ strings.Join(sanitize.Properties.Sanitize.Recover, ",")) } // Link a runtime library if needed. runtimeLibrary := "" if Bool(sanitize.Properties.Sanitize.Address) { runtimeLibrary = config.AddressSanitizerRuntimeLibrary(ctx.toolchain()) } else if Bool(sanitize.Properties.Sanitize.Thread) { runtimeLibrary = config.ThreadSanitizerRuntimeLibrary(ctx.toolchain()) } else if len(diagSanitizers) > 0 { runtimeLibrary = config.UndefinedBehaviorSanitizerRuntimeLibrary(ctx.toolchain()) } if runtimeLibrary != "" { // ASan runtime library must be the first in the link order. flags.libFlags = append([]string{ "${config.ClangAsanLibDir}/" + runtimeLibrary + ctx.toolchain().ShlibSuffix(), }, flags.libFlags...) sanitize.runtimeLibrary = runtimeLibrary // When linking against VNDK, use the vendor variant of the runtime lib sanitize.androidMkRuntimeLibrary = sanitize.runtimeLibrary if ctx.useVndk() { sanitize.androidMkRuntimeLibrary = sanitize.runtimeLibrary + vendorSuffix } } blacklist := android.OptionalPathForModuleSrc(ctx, sanitize.Properties.Sanitize.Blacklist) if blacklist.Valid() { flags.CFlags = append(flags.CFlags, "-fsanitize-blacklist="+blacklist.String()) flags.CFlagsDeps = append(flags.CFlagsDeps, blacklist.Path()) } return flags } func (sanitize *sanitize) AndroidMk(ctx AndroidMkContext, ret *android.AndroidMkData) { ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) { if sanitize.androidMkRuntimeLibrary != "" { fmt.Fprintln(w, "LOCAL_SHARED_LIBRARIES += "+sanitize.androidMkRuntimeLibrary) } }) // Add a suffix for CFI-enabled static libraries to allow surfacing both to make without a // name conflict. if ret.Class == "STATIC_LIBRARIES" && Bool(sanitize.Properties.Sanitize.Cfi) { ret.SubName += ".cfi" } } func (sanitize *sanitize) inSanitizerDir() bool { return sanitize.Properties.InSanitizerDir } func (sanitize *sanitize) getSanitizerBoolPtr(t sanitizerType) *bool { switch t { case asan: return sanitize.Properties.Sanitize.Address case tsan: return sanitize.Properties.Sanitize.Thread case intOverflow: return sanitize.Properties.Sanitize.Integer_overflow case cfi: return sanitize.Properties.Sanitize.Cfi default: panic(fmt.Errorf("unknown sanitizerType %d", t)) } } func (sanitize *sanitize) isUnsanitizedVariant() bool { return !sanitize.isSanitizerEnabled(asan) && !sanitize.isSanitizerEnabled(tsan) && !sanitize.isSanitizerEnabled(cfi) } func (sanitize *sanitize) SetSanitizer(t sanitizerType, b bool) { switch t { case asan: sanitize.Properties.Sanitize.Address = boolPtr(b) if !b { sanitize.Properties.Sanitize.Coverage = nil } case tsan: sanitize.Properties.Sanitize.Thread = boolPtr(b) case intOverflow: sanitize.Properties.Sanitize.Integer_overflow = boolPtr(b) case cfi: sanitize.Properties.Sanitize.Cfi = boolPtr(b) sanitize.Properties.Sanitize.Diag.Cfi = boolPtr(b) default: panic(fmt.Errorf("unknown sanitizerType %d", t)) } if b { sanitize.Properties.SanitizerEnabled = true } } // Check if the sanitizer is explicitly disabled (as opposed to nil by // virtue of not being set). func (sanitize *sanitize) isSanitizerExplicitlyDisabled(t sanitizerType) bool { if sanitize == nil { return false } sanitizerVal := sanitize.getSanitizerBoolPtr(t) return sanitizerVal != nil && *sanitizerVal == false } // There isn't an analog of the method above (ie:isSanitizerExplicitlyEnabled) // because enabling a sanitizer either directly (via the blueprint) or // indirectly (via a mutator) sets the bool ptr to true, and you can't // distinguish between the cases. It isn't needed though - both cases can be // treated identically. func (sanitize *sanitize) isSanitizerEnabled(t sanitizerType) bool { if sanitize == nil { return false } sanitizerVal := sanitize.getSanitizerBoolPtr(t) return sanitizerVal != nil && *sanitizerVal == true } // Propagate asan requirements down from binaries func sanitizerDepsMutator(t sanitizerType) func(android.TopDownMutatorContext) { return func(mctx android.TopDownMutatorContext) { if c, ok := mctx.Module().(*Module); ok && c.sanitize.isSanitizerEnabled(t) { mctx.VisitDepsDepthFirst(func(module android.Module) { if d, ok := module.(*Module); ok && d.sanitize != nil && !Bool(d.sanitize.Properties.Sanitize.Never) && !d.sanitize.isSanitizerExplicitlyDisabled(t) { if (t == cfi && d.static()) || t != cfi { d.sanitize.Properties.SanitizeDep = true } } }) } } } // Propagate the ubsan minimal runtime dependency when there are integer overflow sanitized static dependencies. func minimalRuntimeDepsMutator() func(android.TopDownMutatorContext) { return func(mctx android.TopDownMutatorContext) { if c, ok := mctx.Module().(*Module); ok && c.sanitize != nil { mctx.VisitDepsDepthFirst(func(module android.Module) { if d, ok := module.(*Module); ok && d.static() && d.sanitize != nil { // If a static dependency will be built with the minimal runtime, // make sure we include the ubsan minimal runtime. if enableMinimalRuntime(d.sanitize) { c.sanitize.Properties.MinimalRuntimeDep = true } } }) } } } // Create sanitized variants for modules that need them func sanitizerMutator(t sanitizerType) func(android.BottomUpMutatorContext) { return func(mctx android.BottomUpMutatorContext) { if c, ok := mctx.Module().(*Module); ok && c.sanitize != nil { if c.isDependencyRoot() && c.sanitize.isSanitizerEnabled(t) { modules := mctx.CreateVariations(t.String()) modules[0].(*Module).sanitize.SetSanitizer(t, true) } else if c.sanitize.isSanitizerEnabled(t) || c.sanitize.Properties.SanitizeDep { // Save original sanitizer status before we assign values to variant // 0 as that overwrites the original. isSanitizerEnabled := c.sanitize.isSanitizerEnabled(t) modules := mctx.CreateVariations("", t.String()) modules[0].(*Module).sanitize.SetSanitizer(t, false) modules[1].(*Module).sanitize.SetSanitizer(t, true) modules[0].(*Module).sanitize.Properties.SanitizeDep = false modules[1].(*Module).sanitize.Properties.SanitizeDep = false // We don't need both variants active for anything but CFI-enabled // target static libraries, so suppress the appropriate variant in // all other cases. if t == cfi { if c.static() { if !mctx.Device() { if isSanitizerEnabled { modules[0].(*Module).Properties.PreventInstall = true modules[0].(*Module).Properties.HideFromMake = true } else { modules[1].(*Module).Properties.PreventInstall = true modules[1].(*Module).Properties.HideFromMake = true } } else { cfiStaticLibs := cfiStaticLibs(mctx.Config()) cfiStaticLibsMutex.Lock() *cfiStaticLibs = append(*cfiStaticLibs, c.Name()) cfiStaticLibsMutex.Unlock() } } else { modules[0].(*Module).Properties.PreventInstall = true modules[0].(*Module).Properties.HideFromMake = true } } else if t == asan { if mctx.Device() { // CFI and ASAN are currently mutually exclusive so disable // CFI if this is an ASAN variant. modules[1].(*Module).sanitize.Properties.InSanitizerDir = true modules[1].(*Module).sanitize.SetSanitizer(cfi, false) } if isSanitizerEnabled { modules[0].(*Module).Properties.PreventInstall = true modules[0].(*Module).Properties.HideFromMake = true } else { modules[1].(*Module).Properties.PreventInstall = true modules[1].(*Module).Properties.HideFromMake = true } } } c.sanitize.Properties.SanitizeDep = false } } } func cfiStaticLibs(config android.Config) *[]string { return config.Once("cfiStaticLibs", func() interface{} { return &[]string{} }).(*[]string) } func enableMinimalRuntime(sanitize *sanitize) bool { if !Bool(sanitize.Properties.Sanitize.Address) && (Bool(sanitize.Properties.Sanitize.Integer_overflow) || len(sanitize.Properties.Sanitize.Misc_undefined) > 0) && !(Bool(sanitize.Properties.Sanitize.Diag.Integer_overflow) || Bool(sanitize.Properties.Sanitize.Diag.Cfi) || len(sanitize.Properties.Sanitize.Diag.Misc_undefined) > 0) { return true } return false } func cfiMakeVarsProvider(ctx android.MakeVarsContext) { cfiStaticLibs := cfiStaticLibs(ctx.Config()) sort.Strings(*cfiStaticLibs) ctx.Strict("SOONG_CFI_STATIC_LIBRARIES", strings.Join(*cfiStaticLibs, " ")) }