Files
swift-mirror/lib/Option/SanitizerOptions.cpp
Cory Benfield 565298620b [Sanitizers] Add Scudo support (#28538)
LLVM ships a hardened memory allocator called Scudo:
https://llvm.org/docs/ScudoHardenedAllocator.html. This allocator
provides additional mitigations against heap-based vulnerabilities, but
retains sufficient performance to be safely run in production
applications.

While ideal Swift applications are obviously written in pure Swift, in
practice most applications contain some amount of code written in
less-safe languages. Additionally, plenty of Swift programs themselves
contain unsafe code, particularly when attempting to implement
high-performance data structures. These sources of unsafety introduce
the risk of memory issues, and having the option to use the Scudo
allocator is a useful defense-in-depth tool.

This patch enables `-sanitize=scudo` as an extra `swiftc` flag. This
sanitizer is only supported on Linux, so no further work is required to
enable it on Windows or Apple platforms. As this "sanitizer" is only a
runtime component, we do not require any wider changes to instrument
code. This is similar to clang's `-fsanitize=scudo` flag.

The Swift driver rejects platforms that don't support Scudo using an
existing mechanism in the Driver that is not part of this patch. This
mechanism is in swift::parseSanitizerArgValues(...)
(lib/Option/SanitizerOptions.cpp). The mechanism determines if a
sanitizer is supported by checking for the existence of the
corresponding sanitizer runtime library in the compiler's resource
directory. The Scudo runtime library currently only exists in the
Linux compiler resource directory. This results in the driver only
allowing Scudo when targeting Linux.
2020-01-26 17:27:14 -08:00

272 lines
9.5 KiB
C++

//===--- SanitizerOptions.cpp - Swift Sanitizer options -------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// \file
// This file implements the parsing of sanitizer arguments.
//
//===----------------------------------------------------------------------===//
#include "swift/Option/SanitizerOptions.h"
#include "swift/Basic/Platform.h"
#include "swift/Basic/OptionSet.h"
#include "swift/AST/DiagnosticEngine.h"
#include "swift/AST/DiagnosticsDriver.h"
#include "swift/AST/DiagnosticsFrontend.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Triple.h"
using namespace swift;
static StringRef toStringRef(const SanitizerKind kind) {
switch (kind) {
#define SANITIZER(_, kind, name, file) \
case SanitizerKind::kind: return #name;
#include "swift/Basic/Sanitizers.def"
}
llvm_unreachable("Unknown sanitizer");
}
static StringRef toFileName(const SanitizerKind kind) {
switch (kind) {
#define SANITIZER(_, kind, name, file) \
case SanitizerKind::kind: return #file;
#include "swift/Basic/Sanitizers.def"
}
llvm_unreachable("Unknown sanitizer");
}
static Optional<SanitizerKind> parse(const char* arg) {
return llvm::StringSwitch<Optional<SanitizerKind>>(arg)
#define SANITIZER(_, kind, name, file) .Case(#name, SanitizerKind::kind)
#include "swift/Basic/Sanitizers.def"
.Default(None);
}
llvm::SanitizerCoverageOptions swift::parseSanitizerCoverageArgValue(
const llvm::opt::Arg *A, const llvm::Triple &Triple,
DiagnosticEngine &Diags, OptionSet<SanitizerKind> sanitizers) {
llvm::SanitizerCoverageOptions opts;
// The coverage names here follow the names used by clang's
// ``-fsanitize-coverage=`` flag.
for (int i = 0, n = A->getNumValues(); i != n; ++i) {
if (opts.CoverageType == llvm::SanitizerCoverageOptions::SCK_None) {
opts.CoverageType =
llvm::StringSwitch<llvm::SanitizerCoverageOptions::Type>(
A->getValue(i))
.Case("func", llvm::SanitizerCoverageOptions::SCK_Function)
.Case("bb", llvm::SanitizerCoverageOptions::SCK_BB)
.Case("edge", llvm::SanitizerCoverageOptions::SCK_Edge)
.Default(llvm::SanitizerCoverageOptions::SCK_None);
if (opts.CoverageType != llvm::SanitizerCoverageOptions::SCK_None)
continue;
}
if (StringRef(A->getValue(i)) == "indirect-calls") {
opts.IndirectCalls = true;
continue;
} else if (StringRef(A->getValue(i)) == "trace-bb") {
opts.TraceBB = true;
continue;
} else if (StringRef(A->getValue(i)) == "trace-cmp") {
opts.TraceCmp = true;
continue;
} else if (StringRef(A->getValue(i)) == "8bit-counters") {
opts.Use8bitCounters = true;
continue;
} else if (StringRef(A->getValue(i)) == "trace-pc") {
opts.TracePC = true;
continue;
} else if (StringRef(A->getValue(i)) == "trace-pc-guard") {
opts.TracePCGuard = true;
continue;
}
// Argument is not supported.
Diags.diagnose(SourceLoc(), diag::error_unsupported_option_argument,
A->getOption().getPrefixedName(), A->getValue(i));
return llvm::SanitizerCoverageOptions();
}
if (opts.CoverageType == llvm::SanitizerCoverageOptions::SCK_None) {
Diags.diagnose(SourceLoc(), diag::error_option_missing_required_argument,
A->getSpelling(), "\"func\", \"bb\", \"edge\"");
return llvm::SanitizerCoverageOptions();
}
// Running the sanitizer coverage pass will add undefined symbols to
// functions in compiler-rt's "sanitizer_common". "sanitizer_common" isn't
// shipped as a separate library we can link with. However those are defined
// in the various sanitizer runtime libraries so we require that we are
// doing a sanitized build so we pick up the required functions during
// linking.
if (opts.CoverageType != llvm::SanitizerCoverageOptions::SCK_None &&
!sanitizers) {
Diags.diagnose(SourceLoc(), diag::error_option_requires_sanitizer,
A->getSpelling());
return llvm::SanitizerCoverageOptions();
}
return opts;
}
OptionSet<SanitizerKind> swift::parseSanitizerArgValues(
const llvm::opt::ArgList &Args,
const llvm::opt::Arg *A,
const llvm::Triple &Triple,
DiagnosticEngine &Diags,
llvm::function_ref<bool(llvm::StringRef, bool)> sanitizerRuntimeLibExists) {
OptionSet<SanitizerKind> sanitizerSet;
// Find the sanitizer kind.
for (const char *arg : A->getValues()) {
Optional<SanitizerKind> optKind = parse(arg);
// Unrecognized sanitizer option
if (!optKind.hasValue()) {
Diags.diagnose(SourceLoc(), diag::error_unsupported_option_argument,
A->getOption().getPrefixedName(), arg);
continue;
}
SanitizerKind kind = optKind.getValue();
// Support is determined by existance of the sanitizer library.
auto fileName = toFileName(kind);
bool isShared = (kind != SanitizerKind::Fuzzer);
bool sanitizerSupported = sanitizerRuntimeLibExists(fileName, isShared);
// TSan is explicitly not supported for 32 bits.
if (kind == SanitizerKind::Thread && !Triple.isArch64Bit())
sanitizerSupported = false;
if (!sanitizerSupported) {
SmallString<128> b;
Diags.diagnose(SourceLoc(), diag::error_unsupported_opt_for_target,
(A->getOption().getPrefixedName() + toStringRef(kind))
.toStringRef(b),
Triple.getTriple());
} else {
sanitizerSet |= kind;
}
}
// Check that we're one of the known supported targets for sanitizers.
if (!(Triple.isOSDarwin() || Triple.isOSLinux() || Triple.isOSWindows())) {
SmallString<128> b;
Diags.diagnose(SourceLoc(), diag::error_unsupported_opt_for_target,
(A->getOption().getPrefixedName() +
StringRef(A->getAsString(Args))).toStringRef(b),
Triple.getTriple());
}
// Address and thread sanitizers can not be enabled concurrently.
if ((sanitizerSet & SanitizerKind::Thread)
&& (sanitizerSet & SanitizerKind::Address)) {
SmallString<128> b1;
SmallString<128> b2;
Diags.diagnose(SourceLoc(), diag::error_argument_not_allowed_with,
(A->getOption().getPrefixedName()
+ toStringRef(SanitizerKind::Address)).toStringRef(b1),
(A->getOption().getPrefixedName()
+ toStringRef(SanitizerKind::Thread)).toStringRef(b2));
}
// Scudo can only be run with ubsan.
if (sanitizerSet & SanitizerKind::Scudo) {
OptionSet<SanitizerKind> allowedSet;
allowedSet |= SanitizerKind::Scudo;
allowedSet |= SanitizerKind::Undefined;
auto forbiddenOptions = sanitizerSet - allowedSet;
if (forbiddenOptions) {
SanitizerKind forbidden;
if (forbiddenOptions & SanitizerKind::Address) {
forbidden = SanitizerKind::Address;
} else if (forbiddenOptions & SanitizerKind::Thread) {
forbidden = SanitizerKind::Thread;
} else {
assert(forbiddenOptions & SanitizerKind::Fuzzer);
forbidden = SanitizerKind::Fuzzer;
}
SmallString<128> b1;
SmallString<128> b2;
Diags.diagnose(SourceLoc(), diag::error_argument_not_allowed_with,
(A->getOption().getPrefixedName()
+ toStringRef(SanitizerKind::Scudo)).toStringRef(b1),
(A->getOption().getPrefixedName()
+ toStringRef(forbidden)).toStringRef(b2));
}
}
return sanitizerSet;
}
OptionSet<SanitizerKind> swift::parseSanitizerRecoverArgValues(
const llvm::opt::Arg *A, const OptionSet<SanitizerKind> &enabledSanitizers,
DiagnosticEngine &Diags, bool emitWarnings) {
OptionSet<SanitizerKind> sanitizerRecoverSet;
// Find the sanitizer kind.
for (const char *arg : A->getValues()) {
Optional<SanitizerKind> optKind = parse(arg);
// Unrecognized sanitizer option
if (!optKind.hasValue()) {
Diags.diagnose(SourceLoc(), diag::error_unsupported_option_argument,
A->getOption().getPrefixedName(), arg);
continue;
}
SanitizerKind kind = optKind.getValue();
// Only support ASan for now.
if (kind != SanitizerKind::Address) {
Diags.diagnose(SourceLoc(), diag::error_unsupported_option_argument,
A->getOption().getPrefixedName(), arg);
continue;
}
// Check that the sanitizer is enabled.
if (!(enabledSanitizers & kind)) {
SmallString<128> b;
if (emitWarnings) {
Diags.diagnose(SourceLoc(),
diag::warning_option_requires_specific_sanitizer,
(A->getOption().getPrefixedName() + toStringRef(kind))
.toStringRef(b),
toStringRef(kind));
}
continue;
}
sanitizerRecoverSet |= kind;
}
return sanitizerRecoverSet;
}
std::string swift::getSanitizerList(const OptionSet<SanitizerKind> &Set) {
std::string list;
#define SANITIZER(_, kind, name, file) \
if (Set & SanitizerKind::kind) list += #name ",";
#include "swift/Basic/Sanitizers.def"
if (!list.empty())
list.pop_back(); // Remove last comma
return list;
}