LLVM 17.0.0git
AddressSanitizer.cpp
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1//===- AddressSanitizer.cpp - memory error detector -----------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file is a part of AddressSanitizer, an address basic correctness
10// checker.
11// Details of the algorithm:
12// https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm
13//
14// FIXME: This sanitizer does not yet handle scalable vectors
15//
16//===----------------------------------------------------------------------===//
17
19#include "llvm/ADT/ArrayRef.h"
20#include "llvm/ADT/DenseMap.h"
24#include "llvm/ADT/Statistic.h"
26#include "llvm/ADT/StringRef.h"
27#include "llvm/ADT/Triple.h"
28#include "llvm/ADT/Twine.h"
36#include "llvm/IR/Argument.h"
37#include "llvm/IR/Attributes.h"
38#include "llvm/IR/BasicBlock.h"
39#include "llvm/IR/Comdat.h"
40#include "llvm/IR/Constant.h"
41#include "llvm/IR/Constants.h"
42#include "llvm/IR/DIBuilder.h"
43#include "llvm/IR/DataLayout.h"
45#include "llvm/IR/DebugLoc.h"
47#include "llvm/IR/Function.h"
48#include "llvm/IR/GlobalAlias.h"
49#include "llvm/IR/GlobalValue.h"
51#include "llvm/IR/IRBuilder.h"
52#include "llvm/IR/InlineAsm.h"
53#include "llvm/IR/InstVisitor.h"
54#include "llvm/IR/InstrTypes.h"
55#include "llvm/IR/Instruction.h"
58#include "llvm/IR/Intrinsics.h"
59#include "llvm/IR/LLVMContext.h"
60#include "llvm/IR/MDBuilder.h"
61#include "llvm/IR/Metadata.h"
62#include "llvm/IR/Module.h"
63#include "llvm/IR/Type.h"
64#include "llvm/IR/Use.h"
65#include "llvm/IR/Value.h"
69#include "llvm/Support/Debug.h"
81#include <algorithm>
82#include <cassert>
83#include <cstddef>
84#include <cstdint>
85#include <iomanip>
86#include <limits>
87#include <sstream>
88#include <string>
89#include <tuple>
90
91using namespace llvm;
92
93#define DEBUG_TYPE "asan"
94
96static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
97static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
99 std::numeric_limits<uint64_t>::max();
100static const uint64_t kSmallX86_64ShadowOffsetBase = 0x7FFFFFFF; // < 2G.
102static const uint64_t kLinuxKasan_ShadowOffset64 = 0xdffffc0000000000;
103static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 44;
104static const uint64_t kSystemZ_ShadowOffset64 = 1ULL << 52;
105static const uint64_t kMIPS_ShadowOffsetN32 = 1ULL << 29;
106static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa0000;
107static const uint64_t kMIPS64_ShadowOffset64 = 1ULL << 37;
108static const uint64_t kAArch64_ShadowOffset64 = 1ULL << 36;
109static const uint64_t kLoongArch64_ShadowOffset64 = 1ULL << 46;
110static const uint64_t kRISCV64_ShadowOffset64 = 0xd55550000;
111static const uint64_t kFreeBSD_ShadowOffset32 = 1ULL << 30;
112static const uint64_t kFreeBSD_ShadowOffset64 = 1ULL << 46;
113static const uint64_t kFreeBSDAArch64_ShadowOffset64 = 1ULL << 47;
114static const uint64_t kFreeBSDKasan_ShadowOffset64 = 0xdffff7c000000000;
115static const uint64_t kNetBSD_ShadowOffset32 = 1ULL << 30;
116static const uint64_t kNetBSD_ShadowOffset64 = 1ULL << 46;
117static const uint64_t kNetBSDKasan_ShadowOffset64 = 0xdfff900000000000;
118static const uint64_t kPS_ShadowOffset64 = 1ULL << 40;
119static const uint64_t kWindowsShadowOffset32 = 3ULL << 28;
121
122// The shadow memory space is dynamically allocated.
124
125static const size_t kMinStackMallocSize = 1 << 6; // 64B
126static const size_t kMaxStackMallocSize = 1 << 16; // 64K
127static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3;
128static const uintptr_t kRetiredStackFrameMagic = 0x45E0360E;
129
130const char kAsanModuleCtorName[] = "asan.module_ctor";
131const char kAsanModuleDtorName[] = "asan.module_dtor";
133// On Emscripten, the system needs more than one priorities for constructors.
135const char kAsanReportErrorTemplate[] = "__asan_report_";
136const char kAsanRegisterGlobalsName[] = "__asan_register_globals";
137const char kAsanUnregisterGlobalsName[] = "__asan_unregister_globals";
138const char kAsanRegisterImageGlobalsName[] = "__asan_register_image_globals";
140 "__asan_unregister_image_globals";
141const char kAsanRegisterElfGlobalsName[] = "__asan_register_elf_globals";
142const char kAsanUnregisterElfGlobalsName[] = "__asan_unregister_elf_globals";
143const char kAsanPoisonGlobalsName[] = "__asan_before_dynamic_init";
144const char kAsanUnpoisonGlobalsName[] = "__asan_after_dynamic_init";
145const char kAsanInitName[] = "__asan_init";
146const char kAsanVersionCheckNamePrefix[] = "__asan_version_mismatch_check_v";
147const char kAsanPtrCmp[] = "__sanitizer_ptr_cmp";
148const char kAsanPtrSub[] = "__sanitizer_ptr_sub";
149const char kAsanHandleNoReturnName[] = "__asan_handle_no_return";
150static const int kMaxAsanStackMallocSizeClass = 10;
151const char kAsanStackMallocNameTemplate[] = "__asan_stack_malloc_";
153 "__asan_stack_malloc_always_";
154const char kAsanStackFreeNameTemplate[] = "__asan_stack_free_";
155const char kAsanGenPrefix[] = "___asan_gen_";
156const char kODRGenPrefix[] = "__odr_asan_gen_";
157const char kSanCovGenPrefix[] = "__sancov_gen_";
158const char kAsanSetShadowPrefix[] = "__asan_set_shadow_";
159const char kAsanPoisonStackMemoryName[] = "__asan_poison_stack_memory";
160const char kAsanUnpoisonStackMemoryName[] = "__asan_unpoison_stack_memory";
161
162// ASan version script has __asan_* wildcard. Triple underscore prevents a
163// linker (gold) warning about attempting to export a local symbol.
164const char kAsanGlobalsRegisteredFlagName[] = "___asan_globals_registered";
165
167 "__asan_option_detect_stack_use_after_return";
168
170 "__asan_shadow_memory_dynamic_address";
171
172const char kAsanAllocaPoison[] = "__asan_alloca_poison";
173const char kAsanAllocasUnpoison[] = "__asan_allocas_unpoison";
174
175const char kAMDGPUAddressSharedName[] = "llvm.amdgcn.is.shared";
176const char kAMDGPUAddressPrivateName[] = "llvm.amdgcn.is.private";
177
178// Accesses sizes are powers of two: 1, 2, 4, 8, 16.
179static const size_t kNumberOfAccessSizes = 5;
180
181static const uint64_t kAllocaRzSize = 32;
182
183// ASanAccessInfo implementation constants.
184constexpr size_t kCompileKernelShift = 0;
185constexpr size_t kCompileKernelMask = 0x1;
186constexpr size_t kAccessSizeIndexShift = 1;
187constexpr size_t kAccessSizeIndexMask = 0xf;
188constexpr size_t kIsWriteShift = 5;
189constexpr size_t kIsWriteMask = 0x1;
190
191// Command-line flags.
192
194 "asan-kernel", cl::desc("Enable KernelAddressSanitizer instrumentation"),
195 cl::Hidden, cl::init(false));
196
198 "asan-recover",
199 cl::desc("Enable recovery mode (continue-after-error)."),
200 cl::Hidden, cl::init(false));
201
203 "asan-guard-against-version-mismatch",
204 cl::desc("Guard against compiler/runtime version mismatch."),
205 cl::Hidden, cl::init(true));
206
207// This flag may need to be replaced with -f[no-]asan-reads.
208static cl::opt<bool> ClInstrumentReads("asan-instrument-reads",
209 cl::desc("instrument read instructions"),
210 cl::Hidden, cl::init(true));
211
213 "asan-instrument-writes", cl::desc("instrument write instructions"),
214 cl::Hidden, cl::init(true));
215
216static cl::opt<bool>
217 ClUseStackSafety("asan-use-stack-safety", cl::Hidden, cl::init(false),
218 cl::Hidden, cl::desc("Use Stack Safety analysis results"),
220
222 "asan-instrument-atomics",
223 cl::desc("instrument atomic instructions (rmw, cmpxchg)"), cl::Hidden,
224 cl::init(true));
225
226static cl::opt<bool>
227 ClInstrumentByval("asan-instrument-byval",
228 cl::desc("instrument byval call arguments"), cl::Hidden,
229 cl::init(true));
230
232 "asan-always-slow-path",
233 cl::desc("use instrumentation with slow path for all accesses"), cl::Hidden,
234 cl::init(false));
235
237 "asan-force-dynamic-shadow",
238 cl::desc("Load shadow address into a local variable for each function"),
239 cl::Hidden, cl::init(false));
240
241static cl::opt<bool>
242 ClWithIfunc("asan-with-ifunc",
243 cl::desc("Access dynamic shadow through an ifunc global on "
244 "platforms that support this"),
245 cl::Hidden, cl::init(true));
246
248 "asan-with-ifunc-suppress-remat",
249 cl::desc("Suppress rematerialization of dynamic shadow address by passing "
250 "it through inline asm in prologue."),
251 cl::Hidden, cl::init(true));
252
253// This flag limits the number of instructions to be instrumented
254// in any given BB. Normally, this should be set to unlimited (INT_MAX),
255// but due to http://llvm.org/bugs/show_bug.cgi?id=12652 we temporary
256// set it to 10000.
258 "asan-max-ins-per-bb", cl::init(10000),
259 cl::desc("maximal number of instructions to instrument in any given BB"),
260 cl::Hidden);
261
262// This flag may need to be replaced with -f[no]asan-stack.
263static cl::opt<bool> ClStack("asan-stack", cl::desc("Handle stack memory"),
264 cl::Hidden, cl::init(true));
266 "asan-max-inline-poisoning-size",
267 cl::desc(
268 "Inline shadow poisoning for blocks up to the given size in bytes."),
269 cl::Hidden, cl::init(64));
270
272 "asan-use-after-return",
273 cl::desc("Sets the mode of detection for stack-use-after-return."),
275 clEnumValN(AsanDetectStackUseAfterReturnMode::Never, "never",
276 "Never detect stack use after return."),
278 AsanDetectStackUseAfterReturnMode::Runtime, "runtime",
279 "Detect stack use after return if "
280 "binary flag 'ASAN_OPTIONS=detect_stack_use_after_return' is set."),
281 clEnumValN(AsanDetectStackUseAfterReturnMode::Always, "always",
282 "Always detect stack use after return.")),
283 cl::Hidden, cl::init(AsanDetectStackUseAfterReturnMode::Runtime));
284
285static cl::opt<bool> ClRedzoneByvalArgs("asan-redzone-byval-args",
286 cl::desc("Create redzones for byval "
287 "arguments (extra copy "
288 "required)"), cl::Hidden,
289 cl::init(true));
290
291static cl::opt<bool> ClUseAfterScope("asan-use-after-scope",
292 cl::desc("Check stack-use-after-scope"),
293 cl::Hidden, cl::init(false));
294
295// This flag may need to be replaced with -f[no]asan-globals.
296static cl::opt<bool> ClGlobals("asan-globals",
297 cl::desc("Handle global objects"), cl::Hidden,
298 cl::init(true));
299
300static cl::opt<bool> ClInitializers("asan-initialization-order",
301 cl::desc("Handle C++ initializer order"),
302 cl::Hidden, cl::init(true));
303
305 "asan-detect-invalid-pointer-pair",
306 cl::desc("Instrument <, <=, >, >=, - with pointer operands"), cl::Hidden,
307 cl::init(false));
308
310 "asan-detect-invalid-pointer-cmp",
311 cl::desc("Instrument <, <=, >, >= with pointer operands"), cl::Hidden,
312 cl::init(false));
313
315 "asan-detect-invalid-pointer-sub",
316 cl::desc("Instrument - operations with pointer operands"), cl::Hidden,
317 cl::init(false));
318
320 "asan-realign-stack",
321 cl::desc("Realign stack to the value of this flag (power of two)"),
322 cl::Hidden, cl::init(32));
323
325 "asan-instrumentation-with-call-threshold",
326 cl::desc(
327 "If the function being instrumented contains more than "
328 "this number of memory accesses, use callbacks instead of "
329 "inline checks (-1 means never use callbacks)."),
330 cl::Hidden, cl::init(7000));
331
333 "asan-memory-access-callback-prefix",
334 cl::desc("Prefix for memory access callbacks"), cl::Hidden,
335 cl::init("__asan_"));
336
338 "asan-kernel-mem-intrinsic-prefix",
339 cl::desc("Use prefix for memory intrinsics in KASAN mode"), cl::Hidden,
340 cl::init(false));
341
342static cl::opt<bool>
343 ClInstrumentDynamicAllocas("asan-instrument-dynamic-allocas",
344 cl::desc("instrument dynamic allocas"),
345 cl::Hidden, cl::init(true));
346
348 "asan-skip-promotable-allocas",
349 cl::desc("Do not instrument promotable allocas"), cl::Hidden,
350 cl::init(true));
351
353 "asan-constructor-kind",
354 cl::desc("Sets the ASan constructor kind"),
355 cl::values(clEnumValN(AsanCtorKind::None, "none", "No constructors"),
356 clEnumValN(AsanCtorKind::Global, "global",
357 "Use global constructors")),
358 cl::init(AsanCtorKind::Global), cl::Hidden);
359// These flags allow to change the shadow mapping.
360// The shadow mapping looks like
361// Shadow = (Mem >> scale) + offset
362
363static cl::opt<int> ClMappingScale("asan-mapping-scale",
364 cl::desc("scale of asan shadow mapping"),
365 cl::Hidden, cl::init(0));
366
368 ClMappingOffset("asan-mapping-offset",
369 cl::desc("offset of asan shadow mapping [EXPERIMENTAL]"),
370 cl::Hidden, cl::init(0));
371
372// Optimization flags. Not user visible, used mostly for testing
373// and benchmarking the tool.
374
375static cl::opt<bool> ClOpt("asan-opt", cl::desc("Optimize instrumentation"),
376 cl::Hidden, cl::init(true));
377
378static cl::opt<bool> ClOptimizeCallbacks("asan-optimize-callbacks",
379 cl::desc("Optimize callbacks"),
380 cl::Hidden, cl::init(false));
381
383 "asan-opt-same-temp", cl::desc("Instrument the same temp just once"),
384 cl::Hidden, cl::init(true));
385
386static cl::opt<bool> ClOptGlobals("asan-opt-globals",
387 cl::desc("Don't instrument scalar globals"),
388 cl::Hidden, cl::init(true));
389
391 "asan-opt-stack", cl::desc("Don't instrument scalar stack variables"),
392 cl::Hidden, cl::init(false));
393
395 "asan-stack-dynamic-alloca",
396 cl::desc("Use dynamic alloca to represent stack variables"), cl::Hidden,
397 cl::init(true));
398
400 "asan-force-experiment",
401 cl::desc("Force optimization experiment (for testing)"), cl::Hidden,
402 cl::init(0));
403
404static cl::opt<bool>
405 ClUsePrivateAlias("asan-use-private-alias",
406 cl::desc("Use private aliases for global variables"),
407 cl::Hidden, cl::init(true));
408
409static cl::opt<bool>
410 ClUseOdrIndicator("asan-use-odr-indicator",
411 cl::desc("Use odr indicators to improve ODR reporting"),
412 cl::Hidden, cl::init(true));
413
414static cl::opt<bool>
415 ClUseGlobalsGC("asan-globals-live-support",
416 cl::desc("Use linker features to support dead "
417 "code stripping of globals"),
418 cl::Hidden, cl::init(true));
419
420// This is on by default even though there is a bug in gold:
421// https://sourceware.org/bugzilla/show_bug.cgi?id=19002
422static cl::opt<bool>
423 ClWithComdat("asan-with-comdat",
424 cl::desc("Place ASan constructors in comdat sections"),
425 cl::Hidden, cl::init(true));
426
428 "asan-destructor-kind",
429 cl::desc("Sets the ASan destructor kind. The default is to use the value "
430 "provided to the pass constructor"),
431 cl::values(clEnumValN(AsanDtorKind::None, "none", "No destructors"),
432 clEnumValN(AsanDtorKind::Global, "global",
433 "Use global destructors")),
434 cl::init(AsanDtorKind::Invalid), cl::Hidden);
435
436// Debug flags.
437
438static cl::opt<int> ClDebug("asan-debug", cl::desc("debug"), cl::Hidden,
439 cl::init(0));
440
441static cl::opt<int> ClDebugStack("asan-debug-stack", cl::desc("debug stack"),
442 cl::Hidden, cl::init(0));
443
445 cl::desc("Debug func"));
446
447static cl::opt<int> ClDebugMin("asan-debug-min", cl::desc("Debug min inst"),
448 cl::Hidden, cl::init(-1));
449
450static cl::opt<int> ClDebugMax("asan-debug-max", cl::desc("Debug max inst"),
451 cl::Hidden, cl::init(-1));
452
453STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
454STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
455STATISTIC(NumOptimizedAccessesToGlobalVar,
456 "Number of optimized accesses to global vars");
457STATISTIC(NumOptimizedAccessesToStackVar,
458 "Number of optimized accesses to stack vars");
459
460namespace {
461
462/// This struct defines the shadow mapping using the rule:
463/// shadow = (mem >> Scale) ADD-or-OR Offset.
464/// If InGlobal is true, then
465/// extern char __asan_shadow[];
466/// shadow = (mem >> Scale) + &__asan_shadow
467struct ShadowMapping {
468 int Scale;
469 uint64_t Offset;
470 bool OrShadowOffset;
471 bool InGlobal;
472};
473
474} // end anonymous namespace
475
476static ShadowMapping getShadowMapping(const Triple &TargetTriple, int LongSize,
477 bool IsKasan) {
478 bool IsAndroid = TargetTriple.isAndroid();
479 bool IsIOS = TargetTriple.isiOS() || TargetTriple.isWatchOS() ||
480 TargetTriple.isDriverKit();
481 bool IsMacOS = TargetTriple.isMacOSX();
482 bool IsFreeBSD = TargetTriple.isOSFreeBSD();
483 bool IsNetBSD = TargetTriple.isOSNetBSD();
484 bool IsPS = TargetTriple.isPS();
485 bool IsLinux = TargetTriple.isOSLinux();
486 bool IsPPC64 = TargetTriple.getArch() == Triple::ppc64 ||
487 TargetTriple.getArch() == Triple::ppc64le;
488 bool IsSystemZ = TargetTriple.getArch() == Triple::systemz;
489 bool IsX86_64 = TargetTriple.getArch() == Triple::x86_64;
490 bool IsMIPSN32ABI = TargetTriple.getEnvironment() == Triple::GNUABIN32;
491 bool IsMIPS32 = TargetTriple.isMIPS32();
492 bool IsMIPS64 = TargetTriple.isMIPS64();
493 bool IsArmOrThumb = TargetTriple.isARM() || TargetTriple.isThumb();
494 bool IsAArch64 = TargetTriple.getArch() == Triple::aarch64;
495 bool IsLoongArch64 = TargetTriple.getArch() == Triple::loongarch64;
496 bool IsRISCV64 = TargetTriple.getArch() == Triple::riscv64;
497 bool IsWindows = TargetTriple.isOSWindows();
498 bool IsFuchsia = TargetTriple.isOSFuchsia();
499 bool IsEmscripten = TargetTriple.isOSEmscripten();
500 bool IsAMDGPU = TargetTriple.isAMDGPU();
501
502 ShadowMapping Mapping;
503
504 Mapping.Scale = kDefaultShadowScale;
505 if (ClMappingScale.getNumOccurrences() > 0) {
506 Mapping.Scale = ClMappingScale;
507 }
508
509 if (LongSize == 32) {
510 if (IsAndroid)
511 Mapping.Offset = kDynamicShadowSentinel;
512 else if (IsMIPSN32ABI)
513 Mapping.Offset = kMIPS_ShadowOffsetN32;
514 else if (IsMIPS32)
515 Mapping.Offset = kMIPS32_ShadowOffset32;
516 else if (IsFreeBSD)
517 Mapping.Offset = kFreeBSD_ShadowOffset32;
518 else if (IsNetBSD)
519 Mapping.Offset = kNetBSD_ShadowOffset32;
520 else if (IsIOS)
521 Mapping.Offset = kDynamicShadowSentinel;
522 else if (IsWindows)
523 Mapping.Offset = kWindowsShadowOffset32;
524 else if (IsEmscripten)
525 Mapping.Offset = kEmscriptenShadowOffset;
526 else
527 Mapping.Offset = kDefaultShadowOffset32;
528 } else { // LongSize == 64
529 // Fuchsia is always PIE, which means that the beginning of the address
530 // space is always available.
531 if (IsFuchsia)
532 Mapping.Offset = 0;
533 else if (IsPPC64)
534 Mapping.Offset = kPPC64_ShadowOffset64;
535 else if (IsSystemZ)
536 Mapping.Offset = kSystemZ_ShadowOffset64;
537 else if (IsFreeBSD && IsAArch64)
538 Mapping.Offset = kFreeBSDAArch64_ShadowOffset64;
539 else if (IsFreeBSD && !IsMIPS64) {
540 if (IsKasan)
541 Mapping.Offset = kFreeBSDKasan_ShadowOffset64;
542 else
543 Mapping.Offset = kFreeBSD_ShadowOffset64;
544 } else if (IsNetBSD) {
545 if (IsKasan)
546 Mapping.Offset = kNetBSDKasan_ShadowOffset64;
547 else
548 Mapping.Offset = kNetBSD_ShadowOffset64;
549 } else if (IsPS)
550 Mapping.Offset = kPS_ShadowOffset64;
551 else if (IsLinux && IsX86_64) {
552 if (IsKasan)
553 Mapping.Offset = kLinuxKasan_ShadowOffset64;
554 else
555 Mapping.Offset = (kSmallX86_64ShadowOffsetBase &
556 (kSmallX86_64ShadowOffsetAlignMask << Mapping.Scale));
557 } else if (IsWindows && IsX86_64) {
558 Mapping.Offset = kWindowsShadowOffset64;
559 } else if (IsMIPS64)
560 Mapping.Offset = kMIPS64_ShadowOffset64;
561 else if (IsIOS)
562 Mapping.Offset = kDynamicShadowSentinel;
563 else if (IsMacOS && IsAArch64)
564 Mapping.Offset = kDynamicShadowSentinel;
565 else if (IsAArch64)
566 Mapping.Offset = kAArch64_ShadowOffset64;
567 else if (IsLoongArch64)
568 Mapping.Offset = kLoongArch64_ShadowOffset64;
569 else if (IsRISCV64)
570 Mapping.Offset = kRISCV64_ShadowOffset64;
571 else if (IsAMDGPU)
572 Mapping.Offset = (kSmallX86_64ShadowOffsetBase &
573 (kSmallX86_64ShadowOffsetAlignMask << Mapping.Scale));
574 else
575 Mapping.Offset = kDefaultShadowOffset64;
576 }
577
579 Mapping.Offset = kDynamicShadowSentinel;
580 }
581
582 if (ClMappingOffset.getNumOccurrences() > 0) {
583 Mapping.Offset = ClMappingOffset;
584 }
585
586 // OR-ing shadow offset if more efficient (at least on x86) if the offset
587 // is a power of two, but on ppc64 and loongarch64 we have to use add since
588 // the shadow offset is not necessarily 1/8-th of the address space. On
589 // SystemZ, we could OR the constant in a single instruction, but it's more
590 // efficient to load it once and use indexed addressing.
591 Mapping.OrShadowOffset = !IsAArch64 && !IsPPC64 && !IsSystemZ && !IsPS &&
592 !IsRISCV64 && !IsLoongArch64 &&
593 !(Mapping.Offset & (Mapping.Offset - 1)) &&
594 Mapping.Offset != kDynamicShadowSentinel;
595 bool IsAndroidWithIfuncSupport =
596 IsAndroid && !TargetTriple.isAndroidVersionLT(21);
597 Mapping.InGlobal = ClWithIfunc && IsAndroidWithIfuncSupport && IsArmOrThumb;
598
599 return Mapping;
600}
601
602namespace llvm {
603void getAddressSanitizerParams(const Triple &TargetTriple, int LongSize,
604 bool IsKasan, uint64_t *ShadowBase,
605 int *MappingScale, bool *OrShadowOffset) {
606 auto Mapping = getShadowMapping(TargetTriple, LongSize, IsKasan);
607 *ShadowBase = Mapping.Offset;
608 *MappingScale = Mapping.Scale;
609 *OrShadowOffset = Mapping.OrShadowOffset;
610}
611
613 : Packed(Packed),
614 AccessSizeIndex((Packed >> kAccessSizeIndexShift) & kAccessSizeIndexMask),
615 IsWrite((Packed >> kIsWriteShift) & kIsWriteMask),
616 CompileKernel((Packed >> kCompileKernelShift) & kCompileKernelMask) {}
617
618ASanAccessInfo::ASanAccessInfo(bool IsWrite, bool CompileKernel,
619 uint8_t AccessSizeIndex)
620 : Packed((IsWrite << kIsWriteShift) +
621 (CompileKernel << kCompileKernelShift) +
622 (AccessSizeIndex << kAccessSizeIndexShift)),
623 AccessSizeIndex(AccessSizeIndex), IsWrite(IsWrite),
624 CompileKernel(CompileKernel) {}
625
626} // namespace llvm
627
628static uint64_t getRedzoneSizeForScale(int MappingScale) {
629 // Redzone used for stack and globals is at least 32 bytes.
630 // For scales 6 and 7, the redzone has to be 64 and 128 bytes respectively.
631 return std::max(32U, 1U << MappingScale);
632}
633
635 if (TargetTriple.isOSEmscripten()) {
637 } else {
639 }
640}
641
642namespace {
643
644/// AddressSanitizer: instrument the code in module to find memory bugs.
645struct AddressSanitizer {
646 AddressSanitizer(Module &M, const StackSafetyGlobalInfo *SSGI,
647 bool CompileKernel = false, bool Recover = false,
648 bool UseAfterScope = false,
649 AsanDetectStackUseAfterReturnMode UseAfterReturn =
650 AsanDetectStackUseAfterReturnMode::Runtime)
651 : CompileKernel(ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan
652 : CompileKernel),
653 Recover(ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover),
654 UseAfterScope(UseAfterScope || ClUseAfterScope),
655 UseAfterReturn(ClUseAfterReturn.getNumOccurrences() ? ClUseAfterReturn
656 : UseAfterReturn),
657 SSGI(SSGI) {
658 C = &(M.getContext());
659 LongSize = M.getDataLayout().getPointerSizeInBits();
660 IntptrTy = Type::getIntNTy(*C, LongSize);
661 Int8PtrTy = Type::getInt8PtrTy(*C);
663 TargetTriple = Triple(M.getTargetTriple());
664
665 Mapping = getShadowMapping(TargetTriple, LongSize, this->CompileKernel);
666
667 assert(this->UseAfterReturn != AsanDetectStackUseAfterReturnMode::Invalid);
668 }
669
670 uint64_t getAllocaSizeInBytes(const AllocaInst &AI) const {
671 uint64_t ArraySize = 1;
672 if (AI.isArrayAllocation()) {
673 const ConstantInt *CI = dyn_cast<ConstantInt>(AI.getArraySize());
674 assert(CI && "non-constant array size");
675 ArraySize = CI->getZExtValue();
676 }
677 Type *Ty = AI.getAllocatedType();
678 uint64_t SizeInBytes =
680 return SizeInBytes * ArraySize;
681 }
682
683 /// Check if we want (and can) handle this alloca.
684 bool isInterestingAlloca(const AllocaInst &AI);
685
686 bool ignoreAccess(Instruction *Inst, Value *Ptr);
687 void getInterestingMemoryOperands(
689
690 void instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
691 InterestingMemoryOperand &O, bool UseCalls,
692 const DataLayout &DL);
693 void instrumentPointerComparisonOrSubtraction(Instruction *I);
694 void instrumentAddress(Instruction *OrigIns, Instruction *InsertBefore,
695 Value *Addr, uint32_t TypeSize, bool IsWrite,
696 Value *SizeArgument, bool UseCalls, uint32_t Exp);
697 Instruction *instrumentAMDGPUAddress(Instruction *OrigIns,
698 Instruction *InsertBefore, Value *Addr,
699 uint32_t TypeSize, bool IsWrite,
700 Value *SizeArgument);
701 void instrumentUnusualSizeOrAlignment(Instruction *I,
702 Instruction *InsertBefore, Value *Addr,
703 uint32_t TypeSize, bool IsWrite,
704 Value *SizeArgument, bool UseCalls,
705 uint32_t Exp);
706 Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
707 Value *ShadowValue, uint32_t TypeSize);
708 Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
709 bool IsWrite, size_t AccessSizeIndex,
710 Value *SizeArgument, uint32_t Exp);
711 void instrumentMemIntrinsic(MemIntrinsic *MI);
712 Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
713 bool suppressInstrumentationSiteForDebug(int &Instrumented);
714 bool instrumentFunction(Function &F, const TargetLibraryInfo *TLI);
715 bool maybeInsertAsanInitAtFunctionEntry(Function &F);
716 bool maybeInsertDynamicShadowAtFunctionEntry(Function &F);
717 void markEscapedLocalAllocas(Function &F);
718
719private:
720 friend struct FunctionStackPoisoner;
721
722 void initializeCallbacks(Module &M, const TargetLibraryInfo *TLI);
723
724 bool LooksLikeCodeInBug11395(Instruction *I);
725 bool GlobalIsLinkerInitialized(GlobalVariable *G);
726 bool isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis, Value *Addr,
727 uint64_t TypeSize) const;
728
729 /// Helper to cleanup per-function state.
730 struct FunctionStateRAII {
731 AddressSanitizer *Pass;
732
733 FunctionStateRAII(AddressSanitizer *Pass) : Pass(Pass) {
734 assert(Pass->ProcessedAllocas.empty() &&
735 "last pass forgot to clear cache");
736 assert(!Pass->LocalDynamicShadow);
737 }
738
739 ~FunctionStateRAII() {
740 Pass->LocalDynamicShadow = nullptr;
741 Pass->ProcessedAllocas.clear();
742 }
743 };
744
745 LLVMContext *C;
746 Triple TargetTriple;
747 int LongSize;
748 bool CompileKernel;
749 bool Recover;
750 bool UseAfterScope;
752 Type *IntptrTy;
753 Type *Int8PtrTy;
754 Type *Int32Ty;
755 ShadowMapping Mapping;
756 FunctionCallee AsanHandleNoReturnFunc;
757 FunctionCallee AsanPtrCmpFunction, AsanPtrSubFunction;
758 Constant *AsanShadowGlobal;
759
760 // These arrays is indexed by AccessIsWrite, Experiment and log2(AccessSize).
761 FunctionCallee AsanErrorCallback[2][2][kNumberOfAccessSizes];
762 FunctionCallee AsanMemoryAccessCallback[2][2][kNumberOfAccessSizes];
763
764 // These arrays is indexed by AccessIsWrite and Experiment.
765 FunctionCallee AsanErrorCallbackSized[2][2];
766 FunctionCallee AsanMemoryAccessCallbackSized[2][2];
767
768 FunctionCallee AsanMemmove, AsanMemcpy, AsanMemset;
769 Value *LocalDynamicShadow = nullptr;
770 const StackSafetyGlobalInfo *SSGI;
771 DenseMap<const AllocaInst *, bool> ProcessedAllocas;
772
773 FunctionCallee AMDGPUAddressShared;
774 FunctionCallee AMDGPUAddressPrivate;
775};
776
777class ModuleAddressSanitizer {
778public:
779 ModuleAddressSanitizer(Module &M, bool CompileKernel = false,
780 bool Recover = false, bool UseGlobalsGC = true,
781 bool UseOdrIndicator = true,
782 AsanDtorKind DestructorKind = AsanDtorKind::Global,
783 AsanCtorKind ConstructorKind = AsanCtorKind::Global)
784 : CompileKernel(ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan
785 : CompileKernel),
786 Recover(ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover),
787 UseGlobalsGC(UseGlobalsGC && ClUseGlobalsGC && !this->CompileKernel),
788 // Enable aliases as they should have no downside with ODR indicators.
789 UsePrivateAlias(ClUsePrivateAlias.getNumOccurrences() > 0
791 : UseOdrIndicator),
792 UseOdrIndicator(ClUseOdrIndicator.getNumOccurrences() > 0
794 : UseOdrIndicator),
795 // Not a typo: ClWithComdat is almost completely pointless without
796 // ClUseGlobalsGC (because then it only works on modules without
797 // globals, which are rare); it is a prerequisite for ClUseGlobalsGC;
798 // and both suffer from gold PR19002 for which UseGlobalsGC constructor
799 // argument is designed as workaround. Therefore, disable both
800 // ClWithComdat and ClUseGlobalsGC unless the frontend says it's ok to
801 // do globals-gc.
802 UseCtorComdat(UseGlobalsGC && ClWithComdat && !this->CompileKernel),
803 DestructorKind(DestructorKind),
804 ConstructorKind(ConstructorKind) {
805 C = &(M.getContext());
806 int LongSize = M.getDataLayout().getPointerSizeInBits();
807 IntptrTy = Type::getIntNTy(*C, LongSize);
808 TargetTriple = Triple(M.getTargetTriple());
809 Mapping = getShadowMapping(TargetTriple, LongSize, this->CompileKernel);
810
811 if (ClOverrideDestructorKind != AsanDtorKind::Invalid)
812 this->DestructorKind = ClOverrideDestructorKind;
813 assert(this->DestructorKind != AsanDtorKind::Invalid);
814 }
815
816 bool instrumentModule(Module &);
817
818private:
819 void initializeCallbacks(Module &M);
820
821 bool InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool *CtorComdat);
822 void InstrumentGlobalsCOFF(IRBuilder<> &IRB, Module &M,
823 ArrayRef<GlobalVariable *> ExtendedGlobals,
824 ArrayRef<Constant *> MetadataInitializers);
825 void InstrumentGlobalsELF(IRBuilder<> &IRB, Module &M,
826 ArrayRef<GlobalVariable *> ExtendedGlobals,
827 ArrayRef<Constant *> MetadataInitializers,
828 const std::string &UniqueModuleId);
829 void InstrumentGlobalsMachO(IRBuilder<> &IRB, Module &M,
830 ArrayRef<GlobalVariable *> ExtendedGlobals,
831 ArrayRef<Constant *> MetadataInitializers);
832 void
833 InstrumentGlobalsWithMetadataArray(IRBuilder<> &IRB, Module &M,
834 ArrayRef<GlobalVariable *> ExtendedGlobals,
835 ArrayRef<Constant *> MetadataInitializers);
836
837 GlobalVariable *CreateMetadataGlobal(Module &M, Constant *Initializer,
838 StringRef OriginalName);
839 void SetComdatForGlobalMetadata(GlobalVariable *G, GlobalVariable *Metadata,
840 StringRef InternalSuffix);
841 Instruction *CreateAsanModuleDtor(Module &M);
842
843 const GlobalVariable *getExcludedAliasedGlobal(const GlobalAlias &GA) const;
844 bool shouldInstrumentGlobal(GlobalVariable *G) const;
845 bool ShouldUseMachOGlobalsSection() const;
846 StringRef getGlobalMetadataSection() const;
847 void poisonOneInitializer(Function &GlobalInit, GlobalValue *ModuleName);
848 void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
849 uint64_t getMinRedzoneSizeForGlobal() const {
850 return getRedzoneSizeForScale(Mapping.Scale);
851 }
852 uint64_t getRedzoneSizeForGlobal(uint64_t SizeInBytes) const;
853 int GetAsanVersion(const Module &M) const;
854
855 bool CompileKernel;
856 bool Recover;
857 bool UseGlobalsGC;
858 bool UsePrivateAlias;
859 bool UseOdrIndicator;
860 bool UseCtorComdat;
861 AsanDtorKind DestructorKind;
862 AsanCtorKind ConstructorKind;
863 Type *IntptrTy;
864 LLVMContext *C;
865 Triple TargetTriple;
866 ShadowMapping Mapping;
867 FunctionCallee AsanPoisonGlobals;
868 FunctionCallee AsanUnpoisonGlobals;
869 FunctionCallee AsanRegisterGlobals;
870 FunctionCallee AsanUnregisterGlobals;
871 FunctionCallee AsanRegisterImageGlobals;
872 FunctionCallee AsanUnregisterImageGlobals;
873 FunctionCallee AsanRegisterElfGlobals;
874 FunctionCallee AsanUnregisterElfGlobals;
875
876 Function *AsanCtorFunction = nullptr;
877 Function *AsanDtorFunction = nullptr;
878};
879
880// Stack poisoning does not play well with exception handling.
881// When an exception is thrown, we essentially bypass the code
882// that unpoisones the stack. This is why the run-time library has
883// to intercept __cxa_throw (as well as longjmp, etc) and unpoison the entire
884// stack in the interceptor. This however does not work inside the
885// actual function which catches the exception. Most likely because the
886// compiler hoists the load of the shadow value somewhere too high.
887// This causes asan to report a non-existing bug on 453.povray.
888// It sounds like an LLVM bug.
889struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
890 Function &F;
891 AddressSanitizer &ASan;
892 DIBuilder DIB;
893 LLVMContext *C;
894 Type *IntptrTy;
895 Type *IntptrPtrTy;
896 ShadowMapping Mapping;
897
899 SmallVector<AllocaInst *, 16> StaticAllocasToMoveUp;
901
902 FunctionCallee AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
903 AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
904 FunctionCallee AsanSetShadowFunc[0x100] = {};
905 FunctionCallee AsanPoisonStackMemoryFunc, AsanUnpoisonStackMemoryFunc;
906 FunctionCallee AsanAllocaPoisonFunc, AsanAllocasUnpoisonFunc;
907
908 // Stores a place and arguments of poisoning/unpoisoning call for alloca.
909 struct AllocaPoisonCall {
910 IntrinsicInst *InsBefore;
911 AllocaInst *AI;
913 bool DoPoison;
914 };
915 SmallVector<AllocaPoisonCall, 8> DynamicAllocaPoisonCallVec;
916 SmallVector<AllocaPoisonCall, 8> StaticAllocaPoisonCallVec;
917 bool HasUntracedLifetimeIntrinsic = false;
918
919 SmallVector<AllocaInst *, 1> DynamicAllocaVec;
920 SmallVector<IntrinsicInst *, 1> StackRestoreVec;
921 AllocaInst *DynamicAllocaLayout = nullptr;
922 IntrinsicInst *LocalEscapeCall = nullptr;
923
924 bool HasInlineAsm = false;
925 bool HasReturnsTwiceCall = false;
926 bool PoisonStack;
927
928 FunctionStackPoisoner(Function &F, AddressSanitizer &ASan)
929 : F(F), ASan(ASan), DIB(*F.getParent(), /*AllowUnresolved*/ false),
930 C(ASan.C), IntptrTy(ASan.IntptrTy),
931 IntptrPtrTy(PointerType::get(IntptrTy, 0)), Mapping(ASan.Mapping),
932 PoisonStack(ClStack &&
933 !Triple(F.getParent()->getTargetTriple()).isAMDGPU()) {}
934
935 bool runOnFunction() {
936 if (!PoisonStack)
937 return false;
938
940 copyArgsPassedByValToAllocas();
941
942 // Collect alloca, ret, lifetime instructions etc.
943 for (BasicBlock *BB : depth_first(&F.getEntryBlock())) visit(*BB);
944
945 if (AllocaVec.empty() && DynamicAllocaVec.empty()) return false;
946
947 initializeCallbacks(*F.getParent());
948
949 if (HasUntracedLifetimeIntrinsic) {
950 // If there are lifetime intrinsics which couldn't be traced back to an
951 // alloca, we may not know exactly when a variable enters scope, and
952 // therefore should "fail safe" by not poisoning them.
953 StaticAllocaPoisonCallVec.clear();
954 DynamicAllocaPoisonCallVec.clear();
955 }
956
957 processDynamicAllocas();
958 processStaticAllocas();
959
960 if (ClDebugStack) {
961 LLVM_DEBUG(dbgs() << F);
962 }
963 return true;
964 }
965
966 // Arguments marked with the "byval" attribute are implicitly copied without
967 // using an alloca instruction. To produce redzones for those arguments, we
968 // copy them a second time into memory allocated with an alloca instruction.
969 void copyArgsPassedByValToAllocas();
970
971 // Finds all Alloca instructions and puts
972 // poisoned red zones around all of them.
973 // Then unpoison everything back before the function returns.
974 void processStaticAllocas();
975 void processDynamicAllocas();
976
977 void createDynamicAllocasInitStorage();
978
979 // ----------------------- Visitors.
980 /// Collect all Ret instructions, or the musttail call instruction if it
981 /// precedes the return instruction.
982 void visitReturnInst(ReturnInst &RI) {
984 RetVec.push_back(CI);
985 else
986 RetVec.push_back(&RI);
987 }
988
989 /// Collect all Resume instructions.
990 void visitResumeInst(ResumeInst &RI) { RetVec.push_back(&RI); }
991
992 /// Collect all CatchReturnInst instructions.
993 void visitCleanupReturnInst(CleanupReturnInst &CRI) { RetVec.push_back(&CRI); }
994
995 void unpoisonDynamicAllocasBeforeInst(Instruction *InstBefore,
996 Value *SavedStack) {
997 IRBuilder<> IRB(InstBefore);
998 Value *DynamicAreaPtr = IRB.CreatePtrToInt(SavedStack, IntptrTy);
999 // When we insert _asan_allocas_unpoison before @llvm.stackrestore, we
1000 // need to adjust extracted SP to compute the address of the most recent
1001 // alloca. We have a special @llvm.get.dynamic.area.offset intrinsic for
1002 // this purpose.
1003 if (!isa<ReturnInst>(InstBefore)) {
1004 Function *DynamicAreaOffsetFunc = Intrinsic::getDeclaration(
1005 InstBefore->getModule(), Intrinsic::get_dynamic_area_offset,
1006 {IntptrTy});
1007
1008 Value *DynamicAreaOffset = IRB.CreateCall(DynamicAreaOffsetFunc, {});
1009
1010 DynamicAreaPtr = IRB.CreateAdd(IRB.CreatePtrToInt(SavedStack, IntptrTy),
1011 DynamicAreaOffset);
1012 }
1013
1014 IRB.CreateCall(
1015 AsanAllocasUnpoisonFunc,
1016 {IRB.CreateLoad(IntptrTy, DynamicAllocaLayout), DynamicAreaPtr});
1017 }
1018
1019 // Unpoison dynamic allocas redzones.
1020 void unpoisonDynamicAllocas() {
1021 for (Instruction *Ret : RetVec)
1022 unpoisonDynamicAllocasBeforeInst(Ret, DynamicAllocaLayout);
1023
1024 for (Instruction *StackRestoreInst : StackRestoreVec)
1025 unpoisonDynamicAllocasBeforeInst(StackRestoreInst,
1026 StackRestoreInst->getOperand(0));
1027 }
1028
1029 // Deploy and poison redzones around dynamic alloca call. To do this, we
1030 // should replace this call with another one with changed parameters and
1031 // replace all its uses with new address, so
1032 // addr = alloca type, old_size, align
1033 // is replaced by
1034 // new_size = (old_size + additional_size) * sizeof(type)
1035 // tmp = alloca i8, new_size, max(align, 32)
1036 // addr = tmp + 32 (first 32 bytes are for the left redzone).
1037 // Additional_size is added to make new memory allocation contain not only
1038 // requested memory, but also left, partial and right redzones.
1039 void handleDynamicAllocaCall(AllocaInst *AI);
1040
1041 /// Collect Alloca instructions we want (and can) handle.
1042 void visitAllocaInst(AllocaInst &AI) {
1043 if (!ASan.isInterestingAlloca(AI)) {
1044 if (AI.isStaticAlloca()) {
1045 // Skip over allocas that are present *before* the first instrumented
1046 // alloca, we don't want to move those around.
1047 if (AllocaVec.empty())
1048 return;
1049
1050 StaticAllocasToMoveUp.push_back(&AI);
1051 }
1052 return;
1053 }
1054
1055 if (!AI.isStaticAlloca())
1056 DynamicAllocaVec.push_back(&AI);
1057 else
1058 AllocaVec.push_back(&AI);
1059 }
1060
1061 /// Collect lifetime intrinsic calls to check for use-after-scope
1062 /// errors.
1065 if (ID == Intrinsic::stackrestore) StackRestoreVec.push_back(&II);
1066 if (ID == Intrinsic::localescape) LocalEscapeCall = &II;
1067 if (!ASan.UseAfterScope)
1068 return;
1069 if (!II.isLifetimeStartOrEnd())
1070 return;
1071 // Found lifetime intrinsic, add ASan instrumentation if necessary.
1072 auto *Size = cast<ConstantInt>(II.getArgOperand(0));
1073 // If size argument is undefined, don't do anything.
1074 if (Size->isMinusOne()) return;
1075 // Check that size doesn't saturate uint64_t and can
1076 // be stored in IntptrTy.
1077 const uint64_t SizeValue = Size->getValue().getLimitedValue();
1078 if (SizeValue == ~0ULL ||
1079 !ConstantInt::isValueValidForType(IntptrTy, SizeValue))
1080 return;
1081 // Find alloca instruction that corresponds to llvm.lifetime argument.
1082 // Currently we can only handle lifetime markers pointing to the
1083 // beginning of the alloca.
1084 AllocaInst *AI = findAllocaForValue(II.getArgOperand(1), true);
1085 if (!AI) {
1086 HasUntracedLifetimeIntrinsic = true;
1087 return;
1088 }
1089 // We're interested only in allocas we can handle.
1090 if (!ASan.isInterestingAlloca(*AI))
1091 return;
1092 bool DoPoison = (ID == Intrinsic::lifetime_end);
1093 AllocaPoisonCall APC = {&II, AI, SizeValue, DoPoison};
1094 if (AI->isStaticAlloca())
1095 StaticAllocaPoisonCallVec.push_back(APC);
1097 DynamicAllocaPoisonCallVec.push_back(APC);
1098 }
1099
1100 void visitCallBase(CallBase &CB) {
1101 if (CallInst *CI = dyn_cast<CallInst>(&CB)) {
1102 HasInlineAsm |= CI->isInlineAsm() && &CB != ASan.LocalDynamicShadow;
1103 HasReturnsTwiceCall |= CI->canReturnTwice();
1104 }
1105 }
1106
1107 // ---------------------- Helpers.
1108 void initializeCallbacks(Module &M);
1109
1110 // Copies bytes from ShadowBytes into shadow memory for indexes where
1111 // ShadowMask is not zero. If ShadowMask[i] is zero, we assume that
1112 // ShadowBytes[i] is constantly zero and doesn't need to be overwritten.
1113 void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1114 IRBuilder<> &IRB, Value *ShadowBase);
1115 void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1116 size_t Begin, size_t End, IRBuilder<> &IRB,
1117 Value *ShadowBase);
1118 void copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
1119 ArrayRef<uint8_t> ShadowBytes, size_t Begin,
1120 size_t End, IRBuilder<> &IRB, Value *ShadowBase);
1121
1122 void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);
1123
1124 Value *createAllocaForLayout(IRBuilder<> &IRB, const ASanStackFrameLayout &L,
1125 bool Dynamic);
1126 PHINode *createPHI(IRBuilder<> &IRB, Value *Cond, Value *ValueIfTrue,
1127 Instruction *ThenTerm, Value *ValueIfFalse);
1128};
1129
1130} // end anonymous namespace
1131
1133 raw_ostream &OS, function_ref<StringRef(StringRef)> MapClassName2PassName) {
1135 OS, MapClassName2PassName);
1136 OS << "<";
1137 if (Options.CompileKernel)
1138 OS << "kernel";
1139 OS << ">";
1140}
1141
1143 const AddressSanitizerOptions &Options, bool UseGlobalGC,
1144 bool UseOdrIndicator, AsanDtorKind DestructorKind,
1145 AsanCtorKind ConstructorKind)
1146 : Options(Options), UseGlobalGC(UseGlobalGC),
1147 UseOdrIndicator(UseOdrIndicator), DestructorKind(DestructorKind),
1148 ConstructorKind(ClConstructorKind) {}
1149
1152 ModuleAddressSanitizer ModuleSanitizer(M, Options.CompileKernel,
1153 Options.Recover, UseGlobalGC,
1154 UseOdrIndicator, DestructorKind,
1155 ConstructorKind);
1156 bool Modified = false;
1157 auto &FAM = MAM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
1158 const StackSafetyGlobalInfo *const SSGI =
1160 for (Function &F : M) {
1161 AddressSanitizer FunctionSanitizer(M, SSGI, Options.CompileKernel,
1162 Options.Recover, Options.UseAfterScope,
1163 Options.UseAfterReturn);
1165 Modified |= FunctionSanitizer.instrumentFunction(F, &TLI);
1166 }
1167 Modified |= ModuleSanitizer.instrumentModule(M);
1168 if (!Modified)
1169 return PreservedAnalyses::all();
1170
1172 // GlobalsAA is considered stateless and does not get invalidated unless
1173 // explicitly invalidated; PreservedAnalyses::none() is not enough. Sanitizers
1174 // make changes that require GlobalsAA to be invalidated.
1175 PA.abandon<GlobalsAA>();
1176 return PA;
1177}
1178
1180 size_t Res = llvm::countr_zero(TypeSize / 8);
1182 return Res;
1183}
1184
1185/// Check if \p G has been created by a trusted compiler pass.
1187 // Do not instrument @llvm.global_ctors, @llvm.used, etc.
1188 if (G->getName().startswith("llvm.") ||
1189 // Do not instrument gcov counter arrays.
1190 G->getName().startswith("__llvm_gcov_ctr") ||
1191 // Do not instrument rtti proxy symbols for function sanitizer.
1192 G->getName().startswith("__llvm_rtti_proxy"))
1193 return true;
1194
1195 // Do not instrument asan globals.
1196 if (G->getName().startswith(kAsanGenPrefix) ||
1197 G->getName().startswith(kSanCovGenPrefix) ||
1198 G->getName().startswith(kODRGenPrefix))
1199 return true;
1200
1201 return false;
1202}
1203
1205 Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
1206 unsigned int AddrSpace = PtrTy->getPointerAddressSpace();
1207 if (AddrSpace == 3 || AddrSpace == 5)
1208 return true;
1209 return false;
1210}
1211
1212Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
1213 // Shadow >> scale
1214 Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
1215 if (Mapping.Offset == 0) return Shadow;
1216 // (Shadow >> scale) | offset
1217 Value *ShadowBase;
1218 if (LocalDynamicShadow)
1219 ShadowBase = LocalDynamicShadow;
1220 else
1221 ShadowBase = ConstantInt::get(IntptrTy, Mapping.Offset);
1222 if (Mapping.OrShadowOffset)
1223 return IRB.CreateOr(Shadow, ShadowBase);
1224 else
1225 return IRB.CreateAdd(Shadow, ShadowBase);
1226}
1227
1228// Instrument memset/memmove/memcpy
1229void AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
1230 IRBuilder<> IRB(MI);
1231 if (isa<MemTransferInst>(MI)) {
1232 IRB.CreateCall(
1233 isa<MemMoveInst>(MI) ? AsanMemmove : AsanMemcpy,
1234 {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1235 IRB.CreatePointerCast(MI->getOperand(1), IRB.getInt8PtrTy()),
1236 IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1237 } else if (isa<MemSetInst>(MI)) {
1238 IRB.CreateCall(
1239 AsanMemset,
1240 {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1241 IRB.CreateIntCast(MI->getOperand(1), IRB.getInt32Ty(), false),
1242 IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1243 }
1244 MI->eraseFromParent();
1245}
1246
1247/// Check if we want (and can) handle this alloca.
1248bool AddressSanitizer::isInterestingAlloca(const AllocaInst &AI) {
1249 auto PreviouslySeenAllocaInfo = ProcessedAllocas.find(&AI);
1250
1251 if (PreviouslySeenAllocaInfo != ProcessedAllocas.end())
1252 return PreviouslySeenAllocaInfo->getSecond();
1253
1254 bool IsInteresting =
1255 (AI.getAllocatedType()->isSized() &&
1256 // alloca() may be called with 0 size, ignore it.
1257 ((!AI.isStaticAlloca()) || getAllocaSizeInBytes(AI) > 0) &&
1258 // We are only interested in allocas not promotable to registers.
1259 // Promotable allocas are common under -O0.
1261 // inalloca allocas are not treated as static, and we don't want
1262 // dynamic alloca instrumentation for them as well.
1263 !AI.isUsedWithInAlloca() &&
1264 // swifterror allocas are register promoted by ISel
1265 !AI.isSwiftError() &&
1266 // safe allocas are not interesting
1267 !(SSGI && SSGI->isSafe(AI)));
1268
1269 ProcessedAllocas[&AI] = IsInteresting;
1270 return IsInteresting;
1271}
1272
1273bool AddressSanitizer::ignoreAccess(Instruction *Inst, Value *Ptr) {
1274 // Instrument accesses from different address spaces only for AMDGPU.
1275 Type *PtrTy = cast<PointerType>(Ptr->getType()->getScalarType());
1276 if (PtrTy->getPointerAddressSpace() != 0 &&
1277 !(TargetTriple.isAMDGPU() && !isUnsupportedAMDGPUAddrspace(Ptr)))
1278 return true;
1279
1280 // Ignore swifterror addresses.
1281 // swifterror memory addresses are mem2reg promoted by instruction
1282 // selection. As such they cannot have regular uses like an instrumentation
1283 // function and it makes no sense to track them as memory.
1284 if (Ptr->isSwiftError())
1285 return true;
1286
1287 // Treat memory accesses to promotable allocas as non-interesting since they
1288 // will not cause memory violations. This greatly speeds up the instrumented
1289 // executable at -O0.
1290 if (auto AI = dyn_cast_or_null<AllocaInst>(Ptr))
1291 if (ClSkipPromotableAllocas && !isInterestingAlloca(*AI))
1292 return true;
1293
1294 if (SSGI != nullptr && SSGI->stackAccessIsSafe(*Inst) &&
1296 return true;
1297
1298 return false;
1299}
1300
1301void AddressSanitizer::getInterestingMemoryOperands(
1303 // Do not instrument the load fetching the dynamic shadow address.
1304 if (LocalDynamicShadow == I)
1305 return;
1306
1307 if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
1308 if (!ClInstrumentReads || ignoreAccess(I, LI->getPointerOperand()))
1309 return;
1310 Interesting.emplace_back(I, LI->getPointerOperandIndex(), false,
1311 LI->getType(), LI->getAlign());
1312 } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
1313 if (!ClInstrumentWrites || ignoreAccess(I, SI->getPointerOperand()))
1314 return;
1315 Interesting.emplace_back(I, SI->getPointerOperandIndex(), true,
1316 SI->getValueOperand()->getType(), SI->getAlign());
1317 } else if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
1318 if (!ClInstrumentAtomics || ignoreAccess(I, RMW->getPointerOperand()))
1319 return;
1320 Interesting.emplace_back(I, RMW->getPointerOperandIndex(), true,
1321 RMW->getValOperand()->getType(), std::nullopt);
1322 } else if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
1323 if (!ClInstrumentAtomics || ignoreAccess(I, XCHG->getPointerOperand()))
1324 return;
1325 Interesting.emplace_back(I, XCHG->getPointerOperandIndex(), true,
1326 XCHG->getCompareOperand()->getType(),
1327 std::nullopt);
1328 } else if (auto CI = dyn_cast<CallInst>(I)) {
1329 if (CI->getIntrinsicID() == Intrinsic::masked_load ||
1330 CI->getIntrinsicID() == Intrinsic::masked_store) {
1331 bool IsWrite = CI->getIntrinsicID() == Intrinsic::masked_store;
1332 // Masked store has an initial operand for the value.
1333 unsigned OpOffset = IsWrite ? 1 : 0;
1334 if (IsWrite ? !ClInstrumentWrites : !ClInstrumentReads)
1335 return;
1336
1337 auto BasePtr = CI->getOperand(OpOffset);
1338 if (ignoreAccess(I, BasePtr))
1339 return;
1340 Type *Ty = IsWrite ? CI->getArgOperand(0)->getType() : CI->getType();
1341 MaybeAlign Alignment = Align(1);
1342 // Otherwise no alignment guarantees. We probably got Undef.
1343 if (auto *Op = dyn_cast<ConstantInt>(CI->getOperand(1 + OpOffset)))
1344 Alignment = Op->getMaybeAlignValue();
1345 Value *Mask = CI->getOperand(2 + OpOffset);
1346 Interesting.emplace_back(I, OpOffset, IsWrite, Ty, Alignment, Mask);
1347 } else {
1348 for (unsigned ArgNo = 0; ArgNo < CI->arg_size(); ArgNo++) {
1349 if (!ClInstrumentByval || !CI->isByValArgument(ArgNo) ||
1350 ignoreAccess(I, CI->getArgOperand(ArgNo)))
1351 continue;
1352 Type *Ty = CI->getParamByValType(ArgNo);
1353 Interesting.emplace_back(I, ArgNo, false, Ty, Align(1));
1354 }
1355 }
1356 }
1357}
1358
1359static bool isPointerOperand(Value *V) {
1360 return V->getType()->isPointerTy() || isa<PtrToIntInst>(V);
1361}
1362
1363// This is a rough heuristic; it may cause both false positives and
1364// false negatives. The proper implementation requires cooperation with
1365// the frontend.
1367 if (ICmpInst *Cmp = dyn_cast<ICmpInst>(I)) {
1368 if (!Cmp->isRelational())
1369 return false;
1370 } else {
1371 return false;
1372 }
1373 return isPointerOperand(I->getOperand(0)) &&
1374 isPointerOperand(I->getOperand(1));
1375}
1376
1377// This is a rough heuristic; it may cause both false positives and
1378// false negatives. The proper implementation requires cooperation with
1379// the frontend.
1381 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(I)) {
1382 if (BO->getOpcode() != Instruction::Sub)
1383 return false;
1384 } else {
1385 return false;
1386 }
1387 return isPointerOperand(I->getOperand(0)) &&
1388 isPointerOperand(I->getOperand(1));
1389}
1390
1391bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
1392 // If a global variable does not have dynamic initialization we don't
1393 // have to instrument it. However, if a global does not have initializer
1394 // at all, we assume it has dynamic initializer (in other TU).
1395 if (!G->hasInitializer())
1396 return false;
1397
1398 if (G->hasSanitizerMetadata() && G->getSanitizerMetadata().IsDynInit)
1399 return false;
1400
1401 return true;
1402}
1403
1404void AddressSanitizer::instrumentPointerComparisonOrSubtraction(
1405 Instruction *I) {
1406 IRBuilder<> IRB(I);
1407 FunctionCallee F = isa<ICmpInst>(I) ? AsanPtrCmpFunction : AsanPtrSubFunction;
1408 Value *Param[2] = {I->getOperand(0), I->getOperand(1)};
1409 for (Value *&i : Param) {
1410 if (i->getType()->isPointerTy())
1411 i = IRB.CreatePointerCast(i, IntptrTy);
1412 }
1413 IRB.CreateCall(F, Param);
1414}
1415
1416static void doInstrumentAddress(AddressSanitizer *Pass, Instruction *I,
1417 Instruction *InsertBefore, Value *Addr,
1418 MaybeAlign Alignment, unsigned Granularity,
1419 uint32_t TypeSize, bool IsWrite,
1420 Value *SizeArgument, bool UseCalls,
1421 uint32_t Exp) {
1422 // Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check
1423 // if the data is properly aligned.
1424 if ((TypeSize == 8 || TypeSize == 16 || TypeSize == 32 || TypeSize == 64 ||
1425 TypeSize == 128) &&
1426 (!Alignment || *Alignment >= Granularity || *Alignment >= TypeSize / 8))
1427 return Pass->instrumentAddress(I, InsertBefore, Addr, TypeSize, IsWrite,
1428 nullptr, UseCalls, Exp);
1429 Pass->instrumentUnusualSizeOrAlignment(I, InsertBefore, Addr, TypeSize,
1430 IsWrite, nullptr, UseCalls, Exp);
1431}
1432
1433static void instrumentMaskedLoadOrStore(AddressSanitizer *Pass,
1434 const DataLayout &DL, Type *IntptrTy,
1435 Value *Mask, Instruction *I,
1436 Value *Addr, MaybeAlign Alignment,
1437 unsigned Granularity, Type *OpType,
1438 bool IsWrite, Value *SizeArgument,
1439 bool UseCalls, uint32_t Exp) {
1440 auto *VTy = cast<FixedVectorType>(OpType);
1441 uint64_t ElemTypeSize = DL.getTypeStoreSizeInBits(VTy->getScalarType());
1442 unsigned Num = VTy->getNumElements();
1443 auto Zero = ConstantInt::get(IntptrTy, 0);
1444 for (unsigned Idx = 0; Idx < Num; ++Idx) {
1445 Value *InstrumentedAddress = nullptr;
1446 Instruction *InsertBefore = I;
1447 if (auto *Vector = dyn_cast<ConstantVector>(Mask)) {
1448 // dyn_cast as we might get UndefValue
1449 if (auto *Masked = dyn_cast<ConstantInt>(Vector->getOperand(Idx))) {
1450 if (Masked->isZero())
1451 // Mask is constant false, so no instrumentation needed.
1452 continue;
1453 // If we have a true or undef value, fall through to doInstrumentAddress
1454 // with InsertBefore == I
1455 }
1456 } else {
1457 IRBuilder<> IRB(I);
1458 Value *MaskElem = IRB.CreateExtractElement(Mask, Idx);
1459 Instruction *ThenTerm = SplitBlockAndInsertIfThen(MaskElem, I, false);
1460 InsertBefore = ThenTerm;
1461 }
1462
1463 IRBuilder<> IRB(InsertBefore);
1464 InstrumentedAddress =
1465 IRB.CreateGEP(VTy, Addr, {Zero, ConstantInt::get(IntptrTy, Idx)});
1466 doInstrumentAddress(Pass, I, InsertBefore, InstrumentedAddress, Alignment,
1467 Granularity, ElemTypeSize, IsWrite, SizeArgument,
1468 UseCalls, Exp);
1469 }
1470}
1471
1472void AddressSanitizer::instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
1473 InterestingMemoryOperand &O, bool UseCalls,
1474 const DataLayout &DL) {
1475 Value *Addr = O.getPtr();
1476
1477 // Optimization experiments.
1478 // The experiments can be used to evaluate potential optimizations that remove
1479 // instrumentation (assess false negatives). Instead of completely removing
1480 // some instrumentation, you set Exp to a non-zero value (mask of optimization
1481 // experiments that want to remove instrumentation of this instruction).
1482 // If Exp is non-zero, this pass will emit special calls into runtime
1483 // (e.g. __asan_report_exp_load1 instead of __asan_report_load1). These calls
1484 // make runtime terminate the program in a special way (with a different
1485 // exit status). Then you run the new compiler on a buggy corpus, collect
1486 // the special terminations (ideally, you don't see them at all -- no false
1487 // negatives) and make the decision on the optimization.
1489
1490 if (ClOpt && ClOptGlobals) {
1491 // If initialization order checking is disabled, a simple access to a
1492 // dynamically initialized global is always valid.
1493 GlobalVariable *G = dyn_cast<GlobalVariable>(getUnderlyingObject(Addr));
1494 if (G && (!ClInitializers || GlobalIsLinkerInitialized(G)) &&
1495 isSafeAccess(ObjSizeVis, Addr, O.TypeSize)) {
1496 NumOptimizedAccessesToGlobalVar++;
1497 return;
1498 }
1499 }
1500
1501 if (ClOpt && ClOptStack) {
1502 // A direct inbounds access to a stack variable is always valid.
1503 if (isa<AllocaInst>(getUnderlyingObject(Addr)) &&
1504 isSafeAccess(ObjSizeVis, Addr, O.TypeSize)) {
1505 NumOptimizedAccessesToStackVar++;
1506 return;
1507 }
1508 }
1509
1510 if (O.IsWrite)
1511 NumInstrumentedWrites++;
1512 else
1513 NumInstrumentedReads++;
1514
1515 unsigned Granularity = 1 << Mapping.Scale;
1516 if (O.MaybeMask) {
1517 instrumentMaskedLoadOrStore(this, DL, IntptrTy, O.MaybeMask, O.getInsn(),
1518 Addr, O.Alignment, Granularity, O.OpType,
1519 O.IsWrite, nullptr, UseCalls, Exp);
1520 } else {
1521 doInstrumentAddress(this, O.getInsn(), O.getInsn(), Addr, O.Alignment,
1522 Granularity, O.TypeSize, O.IsWrite, nullptr, UseCalls,
1523 Exp);
1524 }
1525}
1526
1527Instruction *AddressSanitizer::generateCrashCode(Instruction *InsertBefore,
1528 Value *Addr, bool IsWrite,
1529 size_t AccessSizeIndex,
1530 Value *SizeArgument,
1531 uint32_t Exp) {
1532 IRBuilder<> IRB(InsertBefore);
1533 Value *ExpVal = Exp == 0 ? nullptr : ConstantInt::get(IRB.getInt32Ty(), Exp);
1534 CallInst *Call = nullptr;
1535 if (SizeArgument) {
1536 if (Exp == 0)
1537 Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][0],
1538 {Addr, SizeArgument});
1539 else
1540 Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][1],
1541 {Addr, SizeArgument, ExpVal});
1542 } else {
1543 if (Exp == 0)
1544 Call =
1545 IRB.CreateCall(AsanErrorCallback[IsWrite][0][AccessSizeIndex], Addr);
1546 else
1547 Call = IRB.CreateCall(AsanErrorCallback[IsWrite][1][AccessSizeIndex],
1548 {Addr, ExpVal});
1549 }
1550
1551 Call->setCannotMerge();
1552 return Call;
1553}
1554
1555Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
1556 Value *ShadowValue,
1558 size_t Granularity = static_cast<size_t>(1) << Mapping.Scale;
1559 // Addr & (Granularity - 1)
1560 Value *LastAccessedByte =
1561 IRB.CreateAnd(AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
1562 // (Addr & (Granularity - 1)) + size - 1
1563 if (TypeSize / 8 > 1)
1564 LastAccessedByte = IRB.CreateAdd(
1565 LastAccessedByte, ConstantInt::get(IntptrTy, TypeSize / 8 - 1));
1566 // (uint8_t) ((Addr & (Granularity-1)) + size - 1)
1567 LastAccessedByte =
1568 IRB.CreateIntCast(LastAccessedByte, ShadowValue->getType(), false);
1569 // ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue
1570 return IRB.CreateICmpSGE(LastAccessedByte, ShadowValue);
1571}
1572
1573Instruction *AddressSanitizer::instrumentAMDGPUAddress(
1574 Instruction *OrigIns, Instruction *InsertBefore, Value *Addr,
1575 uint32_t TypeSize, bool IsWrite, Value *SizeArgument) {
1576 // Do not instrument unsupported addrspaces.
1578 return nullptr;
1579 Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
1580 // Follow host instrumentation for global and constant addresses.
1581 if (PtrTy->getPointerAddressSpace() != 0)
1582 return InsertBefore;
1583 // Instrument generic addresses in supported addressspaces.
1584 IRBuilder<> IRB(InsertBefore);
1585 Value *AddrLong = IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy());
1586 Value *IsShared = IRB.CreateCall(AMDGPUAddressShared, {AddrLong});
1587 Value *IsPrivate = IRB.CreateCall(AMDGPUAddressPrivate, {AddrLong});
1588 Value *IsSharedOrPrivate = IRB.CreateOr(IsShared, IsPrivate);
1589 Value *Cmp = IRB.CreateNot(IsSharedOrPrivate);
1590 Value *AddrSpaceZeroLanding =
1591 SplitBlockAndInsertIfThen(Cmp, InsertBefore, false);
1592 InsertBefore = cast<Instruction>(AddrSpaceZeroLanding);
1593 return InsertBefore;
1594}
1595
1596void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
1597 Instruction *InsertBefore, Value *Addr,
1598 uint32_t TypeSize, bool IsWrite,
1599 Value *SizeArgument, bool UseCalls,
1600 uint32_t Exp) {
1601 if (TargetTriple.isAMDGPU()) {
1602 InsertBefore = instrumentAMDGPUAddress(OrigIns, InsertBefore, Addr,
1603 TypeSize, IsWrite, SizeArgument);
1604 if (!InsertBefore)
1605 return;
1606 }
1607
1608 IRBuilder<> IRB(InsertBefore);
1609 size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
1610 const ASanAccessInfo AccessInfo(IsWrite, CompileKernel, AccessSizeIndex);
1611
1612 if (UseCalls && ClOptimizeCallbacks) {
1613 const ASanAccessInfo AccessInfo(IsWrite, CompileKernel, AccessSizeIndex);
1614 Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1615 IRB.CreateCall(
1616 Intrinsic::getDeclaration(M, Intrinsic::asan_check_memaccess),
1617 {IRB.CreatePointerCast(Addr, Int8PtrTy),
1618 ConstantInt::get(Int32Ty, AccessInfo.Packed)});
1619 return;
1620 }
1621
1622 Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1623 if (UseCalls) {
1624 if (Exp == 0)
1625 IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][0][AccessSizeIndex],
1626 AddrLong);
1627 else
1628 IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][1][AccessSizeIndex],
1629 {AddrLong, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1630 return;
1631 }
1632
1633 Type *ShadowTy =
1634 IntegerType::get(*C, std::max(8U, TypeSize >> Mapping.Scale));
1635 Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
1636 Value *ShadowPtr = memToShadow(AddrLong, IRB);
1637 Value *ShadowValue =
1638 IRB.CreateLoad(ShadowTy, IRB.CreateIntToPtr(ShadowPtr, ShadowPtrTy));
1639
1640 Value *Cmp = IRB.CreateIsNotNull(ShadowValue);
1641 size_t Granularity = 1ULL << Mapping.Scale;
1642 Instruction *CrashTerm = nullptr;
1643
1644 if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
1645 // We use branch weights for the slow path check, to indicate that the slow
1646 // path is rarely taken. This seems to be the case for SPEC benchmarks.
1648 Cmp, InsertBefore, false, MDBuilder(*C).createBranchWeights(1, 100000));
1649 assert(cast<BranchInst>(CheckTerm)->isUnconditional());
1650 BasicBlock *NextBB = CheckTerm->getSuccessor(0);
1651 IRB.SetInsertPoint(CheckTerm);
1652 Value *Cmp2 = createSlowPathCmp(IRB, AddrLong, ShadowValue, TypeSize);
1653 if (Recover) {
1654 CrashTerm = SplitBlockAndInsertIfThen(Cmp2, CheckTerm, false);
1655 } else {
1656 BasicBlock *CrashBlock =
1657 BasicBlock::Create(*C, "", NextBB->getParent(), NextBB);
1658 CrashTerm = new UnreachableInst(*C, CrashBlock);
1659 BranchInst *NewTerm = BranchInst::Create(CrashBlock, NextBB, Cmp2);
1660 ReplaceInstWithInst(CheckTerm, NewTerm);
1661 }
1662 } else {
1663 CrashTerm = SplitBlockAndInsertIfThen(Cmp, InsertBefore, !Recover);
1664 }
1665
1666 Instruction *Crash = generateCrashCode(CrashTerm, AddrLong, IsWrite,
1667 AccessSizeIndex, SizeArgument, Exp);
1668 Crash->setDebugLoc(OrigIns->getDebugLoc());
1669}
1670
1671// Instrument unusual size or unusual alignment.
1672// We can not do it with a single check, so we do 1-byte check for the first
1673// and the last bytes. We call __asan_report_*_n(addr, real_size) to be able
1674// to report the actual access size.
1675void AddressSanitizer::instrumentUnusualSizeOrAlignment(
1676 Instruction *I, Instruction *InsertBefore, Value *Addr, uint32_t TypeSize,
1677 bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp) {
1678 IRBuilder<> IRB(InsertBefore);
1679 Value *Size = ConstantInt::get(IntptrTy, TypeSize / 8);
1680 Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1681 if (UseCalls) {
1682 if (Exp == 0)
1683 IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][0],
1684 {AddrLong, Size});
1685 else
1686 IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][1],
1687 {AddrLong, Size, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1688 } else {
1689 Value *LastByte = IRB.CreateIntToPtr(
1690 IRB.CreateAdd(AddrLong, ConstantInt::get(IntptrTy, TypeSize / 8 - 1)),
1691 Addr->getType());
1692 instrumentAddress(I, InsertBefore, Addr, 8, IsWrite, Size, false, Exp);
1693 instrumentAddress(I, InsertBefore, LastByte, 8, IsWrite, Size, false, Exp);
1694 }
1695}
1696
1697void ModuleAddressSanitizer::poisonOneInitializer(Function &GlobalInit,
1699 // Set up the arguments to our poison/unpoison functions.
1700 IRBuilder<> IRB(&GlobalInit.front(),
1701 GlobalInit.front().getFirstInsertionPt());
1702
1703 // Add a call to poison all external globals before the given function starts.
1704 Value *ModuleNameAddr = ConstantExpr::getPointerCast(ModuleName, IntptrTy);
1705 IRB.CreateCall(AsanPoisonGlobals, ModuleNameAddr);
1706
1707 // Add calls to unpoison all globals before each return instruction.
1708 for (auto &BB : GlobalInit)
1709 if (ReturnInst *RI = dyn_cast<ReturnInst>(BB.getTerminator()))
1710 CallInst::Create(AsanUnpoisonGlobals, "", RI);
1711}
1712
1713void ModuleAddressSanitizer::createInitializerPoisonCalls(
1715 GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
1716 if (!GV)
1717 return;
1718
1719 ConstantArray *CA = dyn_cast<ConstantArray>(GV->getInitializer());
1720 if (!CA)
1721 return;
1722
1723 for (Use &OP : CA->operands()) {
1724 if (isa<ConstantAggregateZero>(OP)) continue;
1725 ConstantStruct *CS = cast<ConstantStruct>(OP);
1726
1727 // Must have a function or null ptr.
1728 if (Function *F = dyn_cast<Function>(CS->getOperand(1))) {
1729 if (F->getName() == kAsanModuleCtorName) continue;
1730 auto *Priority = cast<ConstantInt>(CS->getOperand(0));
1731 // Don't instrument CTORs that will run before asan.module_ctor.
1732 if (Priority->getLimitedValue() <= GetCtorAndDtorPriority(TargetTriple))
1733 continue;
1734 poisonOneInitializer(*F, ModuleName);
1735 }
1736 }
1737}
1738
1739const GlobalVariable *
1740ModuleAddressSanitizer::getExcludedAliasedGlobal(const GlobalAlias &GA) const {
1741 // In case this function should be expanded to include rules that do not just
1742 // apply when CompileKernel is true, either guard all existing rules with an
1743 // 'if (CompileKernel) { ... }' or be absolutely sure that all these rules
1744 // should also apply to user space.
1745 assert(CompileKernel && "Only expecting to be called when compiling kernel");
1746
1747 const Constant *C = GA.getAliasee();
1748
1749 // When compiling the kernel, globals that are aliased by symbols prefixed
1750 // by "__" are special and cannot be padded with a redzone.
1751 if (GA.getName().startswith("__"))
1752 return dyn_cast<GlobalVariable>(C->stripPointerCastsAndAliases());
1753
1754 return nullptr;
1755}
1756
1757bool ModuleAddressSanitizer::shouldInstrumentGlobal(GlobalVariable *G) const {
1758 Type *Ty = G->getValueType();
1759 LLVM_DEBUG(dbgs() << "GLOBAL: " << *G << "\n");
1760
1761 if (G->hasSanitizerMetadata() && G->getSanitizerMetadata().NoAddress)
1762 return false;
1763 if (!Ty->isSized()) return false;
1764 if (!G->hasInitializer()) return false;
1765 // Globals in address space 1 and 4 are supported for AMDGPU.
1766 if (G->getAddressSpace() &&
1767 !(TargetTriple.isAMDGPU() && !isUnsupportedAMDGPUAddrspace(G)))
1768 return false;
1769 if (GlobalWasGeneratedByCompiler(G)) return false; // Our own globals.
1770 // Two problems with thread-locals:
1771 // - The address of the main thread's copy can't be computed at link-time.
1772 // - Need to poison all copies, not just the main thread's one.
1773 if (G->isThreadLocal()) return false;
1774 // For now, just ignore this Global if the alignment is large.
1775 if (G->getAlign() && *G->getAlign() > getMinRedzoneSizeForGlobal()) return false;
1776
1777 // For non-COFF targets, only instrument globals known to be defined by this
1778 // TU.
1779 // FIXME: We can instrument comdat globals on ELF if we are using the
1780 // GC-friendly metadata scheme.
1781 if (!TargetTriple.isOSBinFormatCOFF()) {
1782 if (!G->hasExactDefinition() || G->hasComdat())
1783 return false;
1784 } else {
1785 // On COFF, don't instrument non-ODR linkages.
1786 if (G->isInterposable())
1787 return false;
1788 }
1789
1790 // If a comdat is present, it must have a selection kind that implies ODR
1791 // semantics: no duplicates, any, or exact match.
1792 if (Comdat *C = G->getComdat()) {
1793 switch (C->getSelectionKind()) {
1794 case Comdat::Any:
1795 case Comdat::ExactMatch:
1797 break;
1798 case Comdat::Largest:
1799 case Comdat::SameSize:
1800 return false;
1801 }
1802 }
1803
1804 if (G->hasSection()) {
1805 // The kernel uses explicit sections for mostly special global variables
1806 // that we should not instrument. E.g. the kernel may rely on their layout
1807 // without redzones, or remove them at link time ("discard.*"), etc.
1808 if (CompileKernel)
1809 return false;
1810
1811 StringRef Section = G->getSection();
1812
1813 // Globals from llvm.metadata aren't emitted, do not instrument them.
1814 if (Section == "llvm.metadata") return false;
1815 // Do not instrument globals from special LLVM sections.
1816 if (Section.contains("__llvm") || Section.contains("__LLVM"))
1817 return false;
1818
1819 // Do not instrument function pointers to initialization and termination
1820 // routines: dynamic linker will not properly handle redzones.
1821 if (Section.startswith(".preinit_array") ||
1822 Section.startswith(".init_array") ||
1823 Section.startswith(".fini_array")) {
1824 return false;
1825 }
1826
1827 // Do not instrument user-defined sections (with names resembling
1828 // valid C identifiers)
1829 if (TargetTriple.isOSBinFormatELF()) {
1830 if (llvm::all_of(Section,
1831 [](char c) { return llvm::isAlnum(c) || c == '_'; }))
1832 return false;
1833 }
1834
1835 // On COFF, if the section name contains '$', it is highly likely that the
1836 // user is using section sorting to create an array of globals similar to
1837 // the way initialization callbacks are registered in .init_array and
1838 // .CRT$XCU. The ATL also registers things in .ATL$__[azm]. Adding redzones
1839 // to such globals is counterproductive, because the intent is that they
1840 // will form an array, and out-of-bounds accesses are expected.
1841 // See https://github.com/google/sanitizers/issues/305
1842 // and http://msdn.microsoft.com/en-US/en-en/library/bb918180(v=vs.120).aspx
1843 if (TargetTriple.isOSBinFormatCOFF() && Section.contains('$')) {
1844 LLVM_DEBUG(dbgs() << "Ignoring global in sorted section (contains '$'): "
1845 << *G << "\n");
1846 return false;
1847 }
1848
1849 if (TargetTriple.isOSBinFormatMachO()) {
1850 StringRef ParsedSegment, ParsedSection;
1851 unsigned TAA = 0, StubSize = 0;
1852 bool TAAParsed;
1854 Section, ParsedSegment, ParsedSection, TAA, TAAParsed, StubSize));
1855
1856 // Ignore the globals from the __OBJC section. The ObjC runtime assumes
1857 // those conform to /usr/lib/objc/runtime.h, so we can't add redzones to
1858 // them.
1859 if (ParsedSegment == "__OBJC" ||
1860 (ParsedSegment == "__DATA" && ParsedSection.startswith("__objc_"))) {
1861 LLVM_DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G << "\n");
1862 return false;
1863 }
1864 // See https://github.com/google/sanitizers/issues/32
1865 // Constant CFString instances are compiled in the following way:
1866 // -- the string buffer is emitted into
1867 // __TEXT,__cstring,cstring_literals
1868 // -- the constant NSConstantString structure referencing that buffer
1869 // is placed into __DATA,__cfstring
1870 // Therefore there's no point in placing redzones into __DATA,__cfstring.
1871 // Moreover, it causes the linker to crash on OS X 10.7
1872 if (ParsedSegment == "__DATA" && ParsedSection == "__cfstring") {
1873 LLVM_DEBUG(dbgs() << "Ignoring CFString: " << *G << "\n");
1874 return false;
1875 }
1876 // The linker merges the contents of cstring_literals and removes the
1877 // trailing zeroes.
1878 if (ParsedSegment == "__TEXT" && (TAA & MachO::S_CSTRING_LITERALS)) {
1879 LLVM_DEBUG(dbgs() << "Ignoring a cstring literal: " << *G << "\n");
1880 return false;
1881 }
1882 }
1883 }
1884
1885 if (CompileKernel) {
1886 // Globals that prefixed by "__" are special and cannot be padded with a
1887 // redzone.
1888 if (G->getName().startswith("__"))
1889 return false;
1890 }
1891
1892 return true;
1893}
1894
1895// On Mach-O platforms, we emit global metadata in a separate section of the
1896// binary in order to allow the linker to properly dead strip. This is only
1897// supported on recent versions of ld64.
1898bool ModuleAddressSanitizer::ShouldUseMachOGlobalsSection() const {
1899 if (!TargetTriple.isOSBinFormatMachO())
1900 return false;
1901
1902 if (TargetTriple.isMacOSX() && !TargetTriple.isMacOSXVersionLT(10, 11))
1903 return true;
1904 if (TargetTriple.isiOS() /* or tvOS */ && !TargetTriple.isOSVersionLT(9))
1905 return true;
1906 if (TargetTriple.isWatchOS() && !TargetTriple.isOSVersionLT(2))
1907 return true;
1908 if (TargetTriple.isDriverKit())
1909 return true;
1910
1911 return false;
1912}
1913
1914StringRef ModuleAddressSanitizer::getGlobalMetadataSection() const {
1915 switch (TargetTriple.getObjectFormat()) {
1916 case Triple::COFF: return ".ASAN$GL";
1917 case Triple::ELF: return "asan_globals";
1918 case Triple::MachO: return "__DATA,__asan_globals,regular";
1919 case Triple::Wasm:
1920 case Triple::GOFF:
1921 case Triple::SPIRV:
1922 case Triple::XCOFF:
1925 "ModuleAddressSanitizer not implemented for object file format");
1927 break;
1928 }
1929 llvm_unreachable("unsupported object format");
1930}
1931
1932void ModuleAddressSanitizer::initializeCallbacks(Module &M) {
1933 IRBuilder<> IRB(*C);
1934
1935 // Declare our poisoning and unpoisoning functions.
1936 AsanPoisonGlobals =
1937 M.getOrInsertFunction(kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy);
1938 AsanUnpoisonGlobals =
1939 M.getOrInsertFunction(kAsanUnpoisonGlobalsName, IRB.getVoidTy());
1940
1941 // Declare functions that register/unregister globals.
1942 AsanRegisterGlobals = M.getOrInsertFunction(
1943 kAsanRegisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);
1944 AsanUnregisterGlobals = M.getOrInsertFunction(
1945 kAsanUnregisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);
1946
1947 // Declare the functions that find globals in a shared object and then invoke
1948 // the (un)register function on them.
1949 AsanRegisterImageGlobals = M.getOrInsertFunction(
1950 kAsanRegisterImageGlobalsName, IRB.getVoidTy(), IntptrTy);
1951 AsanUnregisterImageGlobals = M.getOrInsertFunction(
1953
1954 AsanRegisterElfGlobals =
1955 M.getOrInsertFunction(kAsanRegisterElfGlobalsName, IRB.getVoidTy(),
1956 IntptrTy, IntptrTy, IntptrTy);
1957 AsanUnregisterElfGlobals =
1958 M.getOrInsertFunction(kAsanUnregisterElfGlobalsName, IRB.getVoidTy(),
1959 IntptrTy, IntptrTy, IntptrTy);
1960}
1961
1962// Put the metadata and the instrumented global in the same group. This ensures
1963// that the metadata is discarded if the instrumented global is discarded.
1964void ModuleAddressSanitizer::SetComdatForGlobalMetadata(
1965 GlobalVariable *G, GlobalVariable *Metadata, StringRef InternalSuffix) {
1966 Module &M = *G->getParent();
1967 Comdat *C = G->getComdat();
1968 if (!C) {
1969 if (!G->hasName()) {
1970 // If G is unnamed, it must be internal. Give it an artificial name
1971 // so we can put it in a comdat.
1972 assert(G->hasLocalLinkage());
1973 G->setName(Twine(kAsanGenPrefix) + "_anon_global");
1974 }
1975
1976 if (!InternalSuffix.empty() && G->hasLocalLinkage()) {
1977 std::string Name = std::string(G->getName());
1978 Name += InternalSuffix;
1979 C = M.getOrInsertComdat(Name);
1980 } else {
1981 C = M.getOrInsertComdat(G->getName());
1982 }
1983
1984 // Make this IMAGE_COMDAT_SELECT_NODUPLICATES on COFF. Also upgrade private
1985 // linkage to internal linkage so that a symbol table entry is emitted. This
1986 // is necessary in order to create the comdat group.
1987 if (TargetTriple.isOSBinFormatCOFF()) {
1988 C->setSelectionKind(Comdat::NoDeduplicate);
1989 if (G->hasPrivateLinkage())
1990 G->setLinkage(GlobalValue::InternalLinkage);
1991 }
1992 G->setComdat(C);
1993 }
1994
1995 assert(G->hasComdat());
1996 Metadata->setComdat(G->getComdat());
1997}
1998
1999// Create a separate metadata global and put it in the appropriate ASan
2000// global registration section.
2002ModuleAddressSanitizer::CreateMetadataGlobal(Module &M, Constant *Initializer,
2003 StringRef OriginalName) {
2004 auto Linkage = TargetTriple.isOSBinFormatMachO()
2008 M, Initializer->getType(), false, Linkage, Initializer,
2009 Twine("__asan_global_") + GlobalValue::dropLLVMManglingEscape(OriginalName));
2010 Metadata->setSection(getGlobalMetadataSection());
2011 return Metadata;
2012}
2013
2014Instruction *ModuleAddressSanitizer::CreateAsanModuleDtor(Module &M) {
2015 AsanDtorFunction = Function::createWithDefaultAttr(
2018 AsanDtorFunction->addFnAttr(Attribute::NoUnwind);
2019 // Ensure Dtor cannot be discarded, even if in a comdat.
2020 appendToUsed(M, {AsanDtorFunction});
2021 BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
2022
2023 return ReturnInst::Create(*C, AsanDtorBB);
2024}
2025
2026void ModuleAddressSanitizer::InstrumentGlobalsCOFF(
2027 IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2028 ArrayRef<Constant *> MetadataInitializers) {
2029 assert(ExtendedGlobals.size() == MetadataInitializers.size());
2030 auto &DL = M.getDataLayout();
2031
2032 SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
2033 for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2034 Constant *Initializer = MetadataInitializers[i];
2035 GlobalVariable *G = ExtendedGlobals[i];
2037 CreateMetadataGlobal(M, Initializer, G->getName());
2038 MDNode *MD = MDNode::get(M.getContext(), ValueAsMetadata::get(G));
2039 Metadata->setMetadata(LLVMContext::MD_associated, MD);
2040 MetadataGlobals[i] = Metadata;
2041
2042 // The MSVC linker always inserts padding when linking incrementally. We
2043 // cope with that by aligning each struct to its size, which must be a power
2044 // of two.
2045 unsigned SizeOfGlobalStruct = DL.getTypeAllocSize(Initializer->getType());
2046 assert(isPowerOf2_32(SizeOfGlobalStruct) &&
2047 "global metadata will not be padded appropriately");
2048 Metadata->setAlignment(assumeAligned(SizeOfGlobalStruct));
2049
2050 SetComdatForGlobalMetadata(G, Metadata, "");
2051 }
2052
2053 // Update llvm.compiler.used, adding the new metadata globals. This is
2054 // needed so that during LTO these variables stay alive.
2055 if (!MetadataGlobals.empty())
2056 appendToCompilerUsed(M, MetadataGlobals);
2057}
2058
2059void ModuleAddressSanitizer::InstrumentGlobalsELF(
2060 IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2061 ArrayRef<Constant *> MetadataInitializers,
2062 const std::string &UniqueModuleId) {
2063 assert(ExtendedGlobals.size() == MetadataInitializers.size());
2064
2065 // Putting globals in a comdat changes the semantic and potentially cause
2066 // false negative odr violations at link time. If odr indicators are used, we
2067 // keep the comdat sections, as link time odr violations will be dectected on
2068 // the odr indicator symbols.
2069 bool UseComdatForGlobalsGC = UseOdrIndicator;
2070
2071 SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
2072 for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2073 GlobalVariable *G = ExtendedGlobals[i];
2075 CreateMetadataGlobal(M, MetadataInitializers[i], G->getName());
2076 MDNode *MD = MDNode::get(M.getContext(), ValueAsMetadata::get(G));
2077 Metadata->setMetadata(LLVMContext::MD_associated, MD);
2078 MetadataGlobals[i] = Metadata;
2079
2080 if (UseComdatForGlobalsGC)
2081 SetComdatForGlobalMetadata(G, Metadata, UniqueModuleId);
2082 }
2083
2084 // Update llvm.compiler.used, adding the new metadata globals. This is
2085 // needed so that during LTO these variables stay alive.
2086 if (!MetadataGlobals.empty())
2087 appendToCompilerUsed(M, MetadataGlobals);
2088
2089 // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
2090 // to look up the loaded image that contains it. Second, we can store in it
2091 // whether registration has already occurred, to prevent duplicate
2092 // registration.
2093 //
2094 // Common linkage ensures that there is only one global per shared library.
2095 GlobalVariable *RegisteredFlag = new GlobalVariable(
2096 M, IntptrTy, false, GlobalVariable::CommonLinkage,
2099
2100 // Create start and stop symbols.
2101 GlobalVariable *StartELFMetadata = new GlobalVariable(
2102 M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
2103 "__start_" + getGlobalMetadataSection());
2105 GlobalVariable *StopELFMetadata = new GlobalVariable(
2106 M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
2107 "__stop_" + getGlobalMetadataSection());
2109
2110 // Create a call to register the globals with the runtime.
2111 if (ConstructorKind == AsanCtorKind::Global)
2112 IRB.CreateCall(AsanRegisterElfGlobals,
2113 {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
2114 IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
2115 IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
2116
2117 // We also need to unregister globals at the end, e.g., when a shared library
2118 // gets closed.
2119 if (DestructorKind != AsanDtorKind::None) {
2120 IRBuilder<> IrbDtor(CreateAsanModuleDtor(M));
2121 IrbDtor.CreateCall(AsanUnregisterElfGlobals,
2122 {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
2123 IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
2124 IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
2125 }
2126}
2127
2128void ModuleAddressSanitizer::InstrumentGlobalsMachO(
2129 IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2130 ArrayRef<Constant *> MetadataInitializers) {
2131 assert(ExtendedGlobals.size() == MetadataInitializers.size());
2132
2133 // On recent Mach-O platforms, use a structure which binds the liveness of
2134 // the global variable to the metadata struct. Keep the list of "Liveness" GV
2135 // created to be added to llvm.compiler.used
2136 StructType *LivenessTy = StructType::get(IntptrTy, IntptrTy);
2137 SmallVector<GlobalValue *, 16> LivenessGlobals(ExtendedGlobals.size());
2138
2139 for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2140 Constant *Initializer = MetadataInitializers[i];
2141 GlobalVariable *G = ExtendedGlobals[i];
2143 CreateMetadataGlobal(M, Initializer, G->getName());
2144
2145 // On recent Mach-O platforms, we emit the global metadata in a way that
2146 // allows the linker to properly strip dead globals.
2147 auto LivenessBinder =
2148 ConstantStruct::get(LivenessTy, Initializer->getAggregateElement(0u),
2150 GlobalVariable *Liveness = new GlobalVariable(
2151 M, LivenessTy, false, GlobalVariable::InternalLinkage, LivenessBinder,
2152 Twine("__asan_binder_") + G->getName());
2153 Liveness->setSection("__DATA,__asan_liveness,regular,live_support");
2154 LivenessGlobals[i] = Liveness;
2155 }
2156
2157 // Update llvm.compiler.used, adding the new liveness globals. This is
2158 // needed so that during LTO these variables stay alive. The alternative
2159 // would be to have the linker handling the LTO symbols, but libLTO
2160 // current API does not expose access to the section for each symbol.
2161 if (!LivenessGlobals.empty())
2162 appendToCompilerUsed(M, LivenessGlobals);
2163
2164 // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
2165 // to look up the loaded image that contains it. Second, we can store in it
2166 // whether registration has already occurred, to prevent duplicate
2167 // registration.
2168 //
2169 // common linkage ensures that there is only one global per shared library.
2170 GlobalVariable *RegisteredFlag = new GlobalVariable(
2171 M, IntptrTy, false, GlobalVariable::CommonLinkage,
2174
2175 if (ConstructorKind == AsanCtorKind::Global)
2176 IRB.CreateCall(AsanRegisterImageGlobals,
2177 {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2178
2179 // We also need to unregister globals at the end, e.g., when a shared library
2180 // gets closed.
2181 if (DestructorKind != AsanDtorKind::None) {
2182 IRBuilder<> IrbDtor(CreateAsanModuleDtor(M));
2183 IrbDtor.CreateCall(AsanUnregisterImageGlobals,
2184 {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2185 }
2186}
2187
2188void ModuleAddressSanitizer::InstrumentGlobalsWithMetadataArray(
2189 IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2190 ArrayRef<Constant *> MetadataInitializers) {
2191 assert(ExtendedGlobals.size() == MetadataInitializers.size());
2192 unsigned N = ExtendedGlobals.size();
2193 assert(N > 0);
2194
2195 // On platforms that don't have a custom metadata section, we emit an array
2196 // of global metadata structures.
2197 ArrayType *ArrayOfGlobalStructTy =
2198 ArrayType::get(MetadataInitializers[0]->getType(), N);
2199 auto AllGlobals = new GlobalVariable(
2200 M, ArrayOfGlobalStructTy, false, GlobalVariable::InternalLinkage,
2201 ConstantArray::get(ArrayOfGlobalStructTy, MetadataInitializers), "");
2202 if (Mapping.Scale > 3)
2203 AllGlobals->setAlignment(Align(1ULL << Mapping.Scale));
2204
2205 if (ConstructorKind == AsanCtorKind::Global)
2206 IRB.CreateCall(AsanRegisterGlobals,
2207 {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2208 ConstantInt::get(IntptrTy, N)});
2209
2210 // We also need to unregister globals at the end, e.g., when a shared library
2211 // gets closed.
2212 if (DestructorKind != AsanDtorKind::None) {
2213 IRBuilder<> IrbDtor(CreateAsanModuleDtor(M));
2214 IrbDtor.CreateCall(AsanUnregisterGlobals,
2215 {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2216 ConstantInt::get(IntptrTy, N)});
2217 }
2218}
2219
2220// This function replaces all global variables with new variables that have
2221// trailing redzones. It also creates a function that poisons
2222// redzones and inserts this function into llvm.global_ctors.
2223// Sets *CtorComdat to true if the global registration code emitted into the
2224// asan constructor is comdat-compatible.
2225bool ModuleAddressSanitizer::InstrumentGlobals(IRBuilder<> &IRB, Module &M,
2226 bool *CtorComdat) {
2227 *CtorComdat = false;
2228
2229 // Build set of globals that are aliased by some GA, where
2230 // getExcludedAliasedGlobal(GA) returns the relevant GlobalVariable.
2231 SmallPtrSet<const GlobalVariable *, 16> AliasedGlobalExclusions;
2232 if (CompileKernel) {
2233 for (auto &GA : M.aliases()) {
2234 if (const GlobalVariable *GV = getExcludedAliasedGlobal(GA))
2235 AliasedGlobalExclusions.insert(GV);
2236 }
2237 }
2238
2239 SmallVector<GlobalVariable *, 16> GlobalsToChange;
2240 for (auto &G : M.globals()) {
2241 if (!AliasedGlobalExclusions.count(&G) && shouldInstrumentGlobal(&G))
2242 GlobalsToChange.push_back(&G);
2243 }
2244
2245 size_t n = GlobalsToChange.size();
2246 if (n == 0) {
2247 *CtorComdat = true;
2248 return false;
2249 }
2250
2251 auto &DL = M.getDataLayout();
2252
2253 // A global is described by a structure
2254 // size_t beg;
2255 // size_t size;
2256 // size_t size_with_redzone;
2257 // const char *name;
2258 // const char *module_name;
2259 // size_t has_dynamic_init;
2260 // size_t padding_for_windows_msvc_incremental_link;
2261 // size_t odr_indicator;
2262 // We initialize an array of such structures and pass it to a run-time call.
2263 StructType *GlobalStructTy =
2264 StructType::get(IntptrTy, IntptrTy, IntptrTy, IntptrTy, IntptrTy,
2265 IntptrTy, IntptrTy, IntptrTy);
2267 SmallVector<Constant *, 16> Initializers(n);
2268
2269 bool HasDynamicallyInitializedGlobals = false;
2270
2271 // We shouldn't merge same module names, as this string serves as unique
2272 // module ID in runtime.
2274 M, M.getModuleIdentifier(), /*AllowMerging*/ false, kAsanGenPrefix);
2275
2276 for (size_t i = 0; i < n; i++) {
2277 GlobalVariable *G = GlobalsToChange[i];
2278
2280 if (G->hasSanitizerMetadata())
2281 MD = G->getSanitizerMetadata();
2282
2283 // The runtime library tries demangling symbol names in the descriptor but
2284 // functionality like __cxa_demangle may be unavailable (e.g.
2285 // -static-libstdc++). So we demangle the symbol names here.
2286 std::string NameForGlobal = G->getName().str();
2289 /*AllowMerging*/ true, kAsanGenPrefix);
2290
2291 Type *Ty = G->getValueType();
2292 const uint64_t SizeInBytes = DL.getTypeAllocSize(Ty);
2293 const uint64_t RightRedzoneSize = getRedzoneSizeForGlobal(SizeInBytes);
2294 Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
2295
2296 StructType *NewTy = StructType::get(Ty, RightRedZoneTy);
2297 Constant *NewInitializer = ConstantStruct::get(
2298 NewTy, G->getInitializer(), Constant::getNullValue(RightRedZoneTy));
2299
2300 // Create a new global variable with enough space for a redzone.
2301 GlobalValue::LinkageTypes Linkage = G->getLinkage();
2302 if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage)
2304 GlobalVariable *NewGlobal = new GlobalVariable(
2305 M, NewTy, G->isConstant(), Linkage, NewInitializer, "", G,
2306 G->getThreadLocalMode(), G->getAddressSpace());
2307 NewGlobal->copyAttributesFrom(G);
2308 NewGlobal->setComdat(G->getComdat());
2309 NewGlobal->setAlignment(Align(getMinRedzoneSizeForGlobal()));
2310 // Don't fold globals with redzones. ODR violation detector and redzone
2311 // poisoning implicitly creates a dependence on the global's address, so it
2312 // is no longer valid for it to be marked unnamed_addr.
2314
2315 // Move null-terminated C strings to "__asan_cstring" section on Darwin.
2316 if (TargetTriple.isOSBinFormatMachO() && !G->hasSection() &&
2317 G->isConstant()) {
2318 auto Seq = dyn_cast<ConstantDataSequential>(G->getInitializer());
2319 if (Seq && Seq->isCString())
2320 NewGlobal->setSection("__TEXT,__asan_cstring,regular");
2321 }
2322
2323 // Transfer the debug info and type metadata. The payload starts at offset
2324 // zero so we can copy the metadata over as is.
2325 NewGlobal->copyMetadata(G, 0);
2326
2327 Value *Indices2[2];
2328 Indices2[0] = IRB.getInt32(0);
2329 Indices2[1] = IRB.getInt32(0);
2330
2331 G->replaceAllUsesWith(
2332 ConstantExpr::getGetElementPtr(NewTy, NewGlobal, Indices2, true));
2333 NewGlobal->takeName(G);
2334 G->eraseFromParent();
2335 NewGlobals[i] = NewGlobal;
2336
2337 Constant *ODRIndicator = ConstantExpr::getNullValue(IRB.getInt8PtrTy());
2338 GlobalValue *InstrumentedGlobal = NewGlobal;
2339
2340 bool CanUsePrivateAliases =
2341 TargetTriple.isOSBinFormatELF() || TargetTriple.isOSBinFormatMachO() ||
2342 TargetTriple.isOSBinFormatWasm();
2343 if (CanUsePrivateAliases && UsePrivateAlias) {
2344 // Create local alias for NewGlobal to avoid crash on ODR between
2345 // instrumented and non-instrumented libraries.
2346 InstrumentedGlobal =
2348 }
2349
2350 // ODR should not happen for local linkage.
2351 if (NewGlobal->hasLocalLinkage()) {
2352 ODRIndicator = ConstantExpr::getIntToPtr(ConstantInt::get(IntptrTy, -1),
2353 IRB.getInt8PtrTy());
2354 } else if (UseOdrIndicator) {
2355 // With local aliases, we need to provide another externally visible
2356 // symbol __odr_asan_XXX to detect ODR violation.
2357 auto *ODRIndicatorSym =
2358 new GlobalVariable(M, IRB.getInt8Ty(), false, Linkage,
2360 kODRGenPrefix + NameForGlobal, nullptr,
2361 NewGlobal->getThreadLocalMode());
2362
2363 // Set meaningful attributes for indicator symbol.
2364 ODRIndicatorSym->setVisibility(NewGlobal->getVisibility());
2365 ODRIndicatorSym->setDLLStorageClass(NewGlobal->getDLLStorageClass());
2366 ODRIndicatorSym->setAlignment(Align(1));
2367 ODRIndicator = ODRIndicatorSym;
2368 }
2369
2370 Constant *Initializer = ConstantStruct::get(
2371 GlobalStructTy,
2372 ConstantExpr::getPointerCast(InstrumentedGlobal, IntptrTy),
2373 ConstantInt::get(IntptrTy, SizeInBytes),
2374 ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
2377 ConstantInt::get(IntptrTy, MD.IsDynInit),
2378 Constant::getNullValue(IntptrTy),
2379 ConstantExpr::getPointerCast(ODRIndicator, IntptrTy));
2380
2381 if (ClInitializers && MD.IsDynInit)
2382 HasDynamicallyInitializedGlobals = true;
2383
2384 LLVM_DEBUG(dbgs() << "NEW GLOBAL: " << *NewGlobal << "\n");
2385
2386 Initializers[i] = Initializer;
2387 }
2388
2389 // Add instrumented globals to llvm.compiler.used list to avoid LTO from
2390 // ConstantMerge'ing them.
2391 SmallVector<GlobalValue *, 16> GlobalsToAddToUsedList;
2392 for (size_t i = 0; i < n; i++) {
2393 GlobalVariable *G = NewGlobals[i];
2394 if (G->getName().empty()) continue;
2395 GlobalsToAddToUsedList.push_back(G);
2396 }
2397 appendToCompilerUsed(M, ArrayRef<GlobalValue *>(GlobalsToAddToUsedList));
2398
2399 std::string ELFUniqueModuleId =
2400 (UseGlobalsGC && TargetTriple.isOSBinFormatELF()) ? getUniqueModuleId(&M)
2401 : "";
2402
2403 if (!ELFUniqueModuleId.empty()) {
2404 InstrumentGlobalsELF(IRB, M, NewGlobals, Initializers, ELFUniqueModuleId);
2405 *CtorComdat = true;
2406 } else if (UseGlobalsGC && TargetTriple.isOSBinFormatCOFF()) {
2407 InstrumentGlobalsCOFF(IRB, M, NewGlobals, Initializers);
2408 } else if (UseGlobalsGC && ShouldUseMachOGlobalsSection()) {
2409 InstrumentGlobalsMachO(IRB, M, NewGlobals, Initializers);
2410 } else {
2411 InstrumentGlobalsWithMetadataArray(IRB, M, NewGlobals, Initializers);
2412 }
2413
2414 // Create calls for poisoning before initializers run and unpoisoning after.
2415 if (HasDynamicallyInitializedGlobals)
2416 createInitializerPoisonCalls(M, ModuleName);
2417
2418 LLVM_DEBUG(dbgs() << M);
2419 return true;
2420}
2421
2423ModuleAddressSanitizer::getRedzoneSizeForGlobal(uint64_t SizeInBytes) const {
2424 constexpr uint64_t kMaxRZ = 1 << 18;
2425 const uint64_t MinRZ = getMinRedzoneSizeForGlobal();
2426
2427 uint64_t RZ = 0;
2428 if (SizeInBytes <= MinRZ / 2) {
2429 // Reduce redzone size for small size objects, e.g. int, char[1]. MinRZ is
2430 // at least 32 bytes, optimize when SizeInBytes is less than or equal to
2431 // half of MinRZ.
2432 RZ = MinRZ - SizeInBytes;
2433 } else {
2434 // Calculate RZ, where MinRZ <= RZ <= MaxRZ, and RZ ~ 1/4 * SizeInBytes.
2435 RZ = std::clamp((SizeInBytes / MinRZ / 4) * MinRZ, MinRZ, kMaxRZ);
2436
2437 // Round up to multiple of MinRZ.
2438 if (SizeInBytes % MinRZ)
2439 RZ += MinRZ - (SizeInBytes % MinRZ);
2440 }
2441
2442 assert((RZ + SizeInBytes) % MinRZ == 0);
2443
2444 return RZ;
2445}
2446
2447int ModuleAddressSanitizer::GetAsanVersion(const Module &M) const {
2448 int LongSize = M.getDataLayout().getPointerSizeInBits();
2449 bool isAndroid = Triple(M.getTargetTriple()).isAndroid();
2450 int Version = 8;
2451 // 32-bit Android is one version ahead because of the switch to dynamic
2452 // shadow.
2453 Version += (LongSize == 32 && isAndroid);
2454 return Version;
2455}
2456
2457bool ModuleAddressSanitizer::instrumentModule(Module &M) {
2458 initializeCallbacks(M);
2459
2460 // Create a module constructor. A destructor is created lazily because not all
2461 // platforms, and not all modules need it.
2462 if (ConstructorKind == AsanCtorKind::Global) {
2463 if (CompileKernel) {
2464 // The kernel always builds with its own runtime, and therefore does not
2465 // need the init and version check calls.
2466 AsanCtorFunction = createSanitizerCtor(M, kAsanModuleCtorName);
2467 } else {
2468 std::string AsanVersion = std::to_string(GetAsanVersion(M));
2469 std::string VersionCheckName =
2471 std::tie(AsanCtorFunction, std::ignore) =
2473 kAsanInitName, /*InitArgTypes=*/{},
2474 /*InitArgs=*/{}, VersionCheckName);
2475 }
2476 }
2477
2478 bool CtorComdat = true;
2479 if (ClGlobals) {
2480 assert(AsanCtorFunction || ConstructorKind == AsanCtorKind::None);
2481 if (AsanCtorFunction) {
2482 IRBuilder<> IRB(AsanCtorFunction->getEntryBlock().getTerminator());
2483 InstrumentGlobals(IRB, M, &CtorComdat);
2484 } else {
2485 IRBuilder<> IRB(*C);
2486 InstrumentGlobals(IRB, M, &CtorComdat);
2487 }
2488 }
2489
2490 const uint64_t Priority = GetCtorAndDtorPriority(TargetTriple);
2491
2492 // Put the constructor and destructor in comdat if both
2493 // (1) global instrumentation is not TU-specific
2494 // (2) target is ELF.
2495 if (UseCtorComdat && TargetTriple.isOSBinFormatELF() && CtorComdat) {
2496 if (AsanCtorFunction) {
2497 AsanCtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleCtorName));
2498 appendToGlobalCtors(M, AsanCtorFunction, Priority, AsanCtorFunction);
2499 }
2500 if (AsanDtorFunction) {
2501 AsanDtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleDtorName));
2502 appendToGlobalDtors(M, AsanDtorFunction, Priority, AsanDtorFunction);
2503 }
2504 } else {
2505 if (AsanCtorFunction)
2506 appendToGlobalCtors(M, AsanCtorFunction, Priority);
2507 if (AsanDtorFunction)
2508 appendToGlobalDtors(M, AsanDtorFunction, Priority);
2509 }
2510
2511 return true;
2512}
2513
2514void AddressSanitizer::initializeCallbacks(Module &M, const TargetLibraryInfo *TLI) {
2515 IRBuilder<> IRB(*C);
2516 // Create __asan_report* callbacks.
2517 // IsWrite, TypeSize and Exp are encoded in the function name.
2518 for (int Exp = 0; Exp < 2; Exp++) {
2519 for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
2520 const std::string TypeStr = AccessIsWrite ? "store" : "load";
2521 const std::string ExpStr = Exp ? "exp_" : "";
2522 const std::string EndingStr = Recover ? "_noabort" : "";
2523
2524 SmallVector<Type *, 3> Args2 = {IntptrTy, IntptrTy};
2525 SmallVector<Type *, 2> Args1{1, IntptrTy};
2526 AttributeList AL2;
2527 AttributeList AL1;
2528 if (Exp) {
2529 Type *ExpType = Type::getInt32Ty(*C);
2530 Args2.push_back(ExpType);
2531 Args1.push_back(ExpType);
2532 if (auto AK = TLI->getExtAttrForI32Param(false)) {
2533 AL2 = AL2.addParamAttribute(*C, 2, AK);
2534 AL1 = AL1.addParamAttribute(*C, 1, AK);
2535 }
2536 }
2537 AsanErrorCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
2538 kAsanReportErrorTemplate + ExpStr + TypeStr + "_n" + EndingStr,
2539 FunctionType::get(IRB.getVoidTy(), Args2, false), AL2);
2540
2541 AsanMemoryAccessCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
2542 ClMemoryAccessCallbackPrefix + ExpStr + TypeStr + "N" + EndingStr,
2543 FunctionType::get(IRB.getVoidTy(), Args2, false), AL2);
2544
2545 for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
2546 AccessSizeIndex++) {
2547 const std::string Suffix = TypeStr + itostr(1ULL << AccessSizeIndex);
2548 AsanErrorCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2549 M.getOrInsertFunction(
2550 kAsanReportErrorTemplate + ExpStr + Suffix + EndingStr,
2551 FunctionType::get(IRB.getVoidTy(), Args1, false), AL1);
2552
2553 AsanMemoryAccessCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2554 M.getOrInsertFunction(
2555 ClMemoryAccessCallbackPrefix + ExpStr + Suffix + EndingStr,
2556 FunctionType::get(IRB.getVoidTy(), Args1, false), AL1);
2557 }
2558 }
2559 }
2560
2561 const std::string MemIntrinCallbackPrefix =
2562 (CompileKernel && !ClKasanMemIntrinCallbackPrefix)
2563 ? std::string("")
2565 AsanMemmove = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memmove",
2566 IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2567 IRB.getInt8PtrTy(), IntptrTy);
2568 AsanMemcpy = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memcpy",
2569 IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2570 IRB.getInt8PtrTy(), IntptrTy);
2571 AsanMemset = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memset",
2572 TLI->getAttrList(C, {1}, /*Signed=*/false),
2573 IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2574 IRB.getInt32Ty(), IntptrTy);
2575
2576 AsanHandleNoReturnFunc =
2577 M.getOrInsertFunction(kAsanHandleNoReturnName, IRB.getVoidTy());
2578
2579 AsanPtrCmpFunction =
2580 M.getOrInsertFunction(kAsanPtrCmp, IRB.getVoidTy(), IntptrTy, IntptrTy);
2581 AsanPtrSubFunction =
2582 M.getOrInsertFunction(kAsanPtrSub, IRB.getVoidTy(), IntptrTy, IntptrTy);
2583 if (Mapping.InGlobal)
2584 AsanShadowGlobal = M.getOrInsertGlobal("__asan_shadow",
2585 ArrayType::get(IRB.getInt8Ty(), 0));
2586
2587 AMDGPUAddressShared = M.getOrInsertFunction(
2589 AMDGPUAddressPrivate = M.getOrInsertFunction(
2591}
2592
2593bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
2594 // For each NSObject descendant having a +load method, this method is invoked
2595 // by the ObjC runtime before any of the static constructors is called.
2596 // Therefore we need to instrument such methods with a call to __asan_init
2597 // at the beginning in order to initialize our runtime before any access to
2598 // the shadow memory.
2599 // We cannot just ignore these methods, because they may call other
2600 // instrumented functions.
2601 if (F.getName().find(" load]") != std::string::npos) {
2602 FunctionCallee AsanInitFunction =
2603 declareSanitizerInitFunction(*F.getParent(), kAsanInitName, {});
2604 IRBuilder<> IRB(&F.front(), F.front().begin());
2605 IRB.CreateCall(AsanInitFunction, {});
2606 return true;
2607 }
2608 return false;
2609}
2610
2611bool AddressSanitizer::maybeInsertDynamicShadowAtFunctionEntry(Function &F) {
2612 // Generate code only when dynamic addressing is needed.
2613 if (Mapping.Offset != kDynamicShadowSentinel)
2614 return false;
2615
2616 IRBuilder<> IRB(&F.front().front());
2617 if (Mapping.InGlobal) {
2619 // An empty inline asm with input reg == output reg.
2620 // An opaque pointer-to-int cast, basically.
2622 FunctionType::get(IntptrTy, {AsanShadowGlobal->getType()}, false),
2623 StringRef(""), StringRef("=r,0"),
2624 /*hasSideEffects=*/false);
2625 LocalDynamicShadow =
2626 IRB.CreateCall(Asm, {AsanShadowGlobal}, ".asan.shadow");
2627 } else {
2628 LocalDynamicShadow =
2629 IRB.CreatePointerCast(AsanShadowGlobal, IntptrTy, ".asan.shadow");
2630 }
2631 } else {
2632 Value *GlobalDynamicAddress = F.getParent()->getOrInsertGlobal(
2634 LocalDynamicShadow = IRB.CreateLoad(IntptrTy, GlobalDynamicAddress);
2635 }
2636 return true;
2637}
2638
2639void AddressSanitizer::markEscapedLocalAllocas(Function &F) {
2640 // Find the one possible call to llvm.localescape and pre-mark allocas passed
2641 // to it as uninteresting. This assumes we haven't started processing allocas
2642 // yet. This check is done up front because iterating the use list in
2643 // isInterestingAlloca would be algorithmically slower.
2644 assert(ProcessedAllocas.empty() && "must process localescape before allocas");
2645
2646 // Try to get the declaration of llvm.localescape. If it's not in the module,
2647 // we can exit early.
2648 if (!F.getParent()->getFunction("llvm.localescape")) return;
2649
2650 // Look for a call to llvm.localescape call in the entry block. It can't be in
2651 // any other block.
2652 for (Instruction &I : F.getEntryBlock()) {
2653 IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I);
2654 if (II && II->getIntrinsicID() == Intrinsic::localescape) {
2655 // We found a call. Mark all the allocas passed in as uninteresting.
2656 for (Value *Arg : II->args()) {
2657 AllocaInst *AI = dyn_cast<AllocaInst>(Arg->stripPointerCasts());
2658 assert(AI && AI->isStaticAlloca() &&
2659 "non-static alloca arg to localescape");
2660 ProcessedAllocas[AI] = false;
2661 }
2662 break;
2663 }
2664 }
2665}
2666
2667bool AddressSanitizer::suppressInstrumentationSiteForDebug(int &Instrumented) {
2668 bool ShouldInstrument =
2669 ClDebugMin < 0 || ClDebugMax < 0 ||
2670 (Instrumented >= ClDebugMin && Instrumented <= ClDebugMax);
2671 Instrumented++;
2672 return !ShouldInstrument;
2673}
2674
2675bool AddressSanitizer::instrumentFunction(Function &F,
2676 const TargetLibraryInfo *TLI) {
2677 if (F.empty())
2678 return false;
2679 if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
2680 if (!ClDebugFunc.empty() && ClDebugFunc == F.getName()) return false;
2681 if (F.getName().startswith("__asan_")) return false;
2682
2683 bool FunctionModified = false;
2684
2685 // If needed, insert __asan_init before checking for SanitizeAddress attr.
2686 // This function needs to be called even if the function body is not
2687 // instrumented.
2688 if (maybeInsertAsanInitAtFunctionEntry(F))
2689 FunctionModified = true;
2690
2691 // Leave if the function doesn't need instrumentation.
2692 if (!F.hasFnAttribute(Attribute::SanitizeAddress)) return FunctionModified;
2693
2694 if (F.hasFnAttribute(Attribute::DisableSanitizerInstrumentation))
2695 return FunctionModified;
2696
2697 LLVM_DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
2698
2699 initializeCallbacks(*F.getParent(), TLI);
2700
2701 FunctionStateRAII CleanupObj(this);
2702
2703 FunctionModified |= maybeInsertDynamicShadowAtFunctionEntry(F);
2704
2705 // We can't instrument allocas used with llvm.localescape. Only static allocas
2706 // can be passed to that intrinsic.
2707 markEscapedLocalAllocas(F);
2708
2709 // We want to instrument every address only once per basic block (unless there
2710 // are calls between uses).
2711 SmallPtrSet<Value *, 16> TempsToInstrument;
2712 SmallVector<InterestingMemoryOperand, 16> OperandsToInstrument;
2713 SmallVector<MemIntrinsic *, 16> IntrinToInstrument;
2714 SmallVector<Instruction *, 8> NoReturnCalls;
2716 SmallVector<Instruction *, 16> PointerComparisonsOrSubtracts;
2717
2718 // Fill the set of memory operations to instrument.
2719 for (auto &BB : F) {
2720 AllBlocks.push_back(&BB);
2721 TempsToInstrument.clear();
2722 int NumInsnsPerBB = 0;
2723 for (auto &Inst : BB) {
2724 if (LooksLikeCodeInBug11395(&Inst)) return false;
2725 // Skip instructions inserted by another instrumentation.
2726 if (Inst.hasMetadata(LLVMContext::MD_nosanitize))
2727 continue;
2728 SmallVector<InterestingMemoryOperand, 1> InterestingOperands;
2729 getInterestingMemoryOperands(&Inst, InterestingOperands);
2730
2731 if (!InterestingOperands.empty()) {
2732 for (auto &Operand : InterestingOperands) {
2733 if (ClOpt && ClOptSameTemp) {
2734 Value *Ptr = Operand.getPtr();
2735 // If we have a mask, skip instrumentation if we've already
2736 // instrumented the full object. But don't add to TempsToInstrument
2737 // because we might get another load/store with a different mask.
2738 if (Operand.MaybeMask) {
2739 if (TempsToInstrument.count(Ptr))
2740 continue; // We've seen this (whole) temp in the current BB.
2741 } else {
2742 if (!TempsToInstrument.insert(Ptr).second)
2743 continue; // We've seen this temp in the current BB.
2744 }
2745 }
2746 OperandsToInstrument.push_back(Operand);
2747 NumInsnsPerBB++;
2748 }
2749 } else if (((ClInvalidPointerPairs || ClInvalidPointerCmp) &&
2753 PointerComparisonsOrSubtracts.push_back(&Inst);
2754 } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(&Inst)) {
2755 // ok, take it.
2756 IntrinToInstrument.push_back(MI);
2757 NumInsnsPerBB++;
2758 } else {
2759 if (auto *CB = dyn_cast<CallBase>(&Inst)) {
2760 // A call inside BB.
2761 TempsToInstrument.clear();
2762 if (CB->doesNotReturn())
2763 NoReturnCalls.push_back(CB);
2764 }
2765 if (CallInst *CI = dyn_cast<CallInst>(&Inst))
2767 }
2768 if (NumInsnsPerBB >= ClMaxInsnsToInstrumentPerBB) break;
2769 }
2770 }
2771
2772 bool UseCalls = (ClInstrumentationWithCallsThreshold >= 0 &&
2773 OperandsToInstrument.size() + IntrinToInstrument.size() >
2775 const DataLayout &DL = F.getParent()->getDataLayout();
2776 ObjectSizeOpts ObjSizeOpts;
2777 ObjSizeOpts.RoundToAlign = true;
2778 ObjectSizeOffsetVisitor ObjSizeVis(DL, TLI, F.getContext(), ObjSizeOpts);
2779
2780 // Instrument.
2781 int NumInstrumented = 0;
2782 for (auto &Operand : OperandsToInstrument) {
2783 if (!suppressInstrumentationSiteForDebug(NumInstrumented))
2784 instrumentMop(ObjSizeVis, Operand, UseCalls,
2785 F.getParent()->getDataLayout());
2786 FunctionModified = true;
2787 }
2788 for (auto *Inst : IntrinToInstrument) {
2789 if (!suppressInstrumentationSiteForDebug(NumInstrumented))
2790 instrumentMemIntrinsic(Inst);
2791 FunctionModified = true;
2792 }
2793
2794 FunctionStackPoisoner FSP(F, *this);
2795 bool ChangedStack = FSP.runOnFunction();
2796
2797 // We must unpoison the stack before NoReturn calls (throw, _exit, etc).
2798 // See e.g. https://github.com/google/sanitizers/issues/37
2799 for (auto *CI : NoReturnCalls) {
2800 IRBuilder<> IRB(CI);
2801 IRB.CreateCall(AsanHandleNoReturnFunc, {});
2802 }
2803
2804 for (auto *Inst : PointerComparisonsOrSubtracts) {
2805 instrumentPointerComparisonOrSubtraction(Inst);
2806 FunctionModified = true;
2807 }
2808
2809 if (ChangedStack || !NoReturnCalls.empty())
2810 FunctionModified = true;
2811
2812 LLVM_DEBUG(dbgs() << "ASAN done instrumenting: " << FunctionModified << " "
2813 << F << "\n");
2814
2815 return FunctionModified;
2816}
2817
2818// Workaround for bug 11395: we don't want to instrument stack in functions
2819// with large assembly blobs (32-bit only), otherwise reg alloc may crash.
2820// FIXME: remove once the bug 11395 is fixed.
2821bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
2822 if (LongSize != 32) return false;
2823 CallInst *CI = dyn_cast<CallInst>(I);
2824 if (!CI || !CI->isInlineAsm()) return false;
2825 if (CI->arg_size() <= 5)
2826 return false;
2827 // We have inline assembly with quite a few arguments.
2828 return true;
2829}
2830
2831void FunctionStackPoisoner::initializeCallbacks(Module &M) {
2832 IRBuilder<> IRB(*C);
2833 if (ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Always ||
2834 ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Runtime) {
2835 const char *MallocNameTemplate =
2836 ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Always
2839 for (int Index = 0; Index <= kMaxAsanStackMallocSizeClass; Index++) {
2840 std::string Suffix = itostr(Index);
2841 AsanStackMallocFunc[Index] = M.getOrInsertFunction(
2842 MallocNameTemplate + Suffix, IntptrTy, IntptrTy);
2843 AsanStackFreeFunc[Index] =
2844 M.getOrInsertFunction(kAsanStackFreeNameTemplate + Suffix,
2845 IRB.getVoidTy(), IntptrTy, IntptrTy);
2846 }
2847 }
2848 if (ASan.UseAfterScope) {
2849 AsanPoisonStackMemoryFunc = M.getOrInsertFunction(
2850 kAsanPoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
2851 AsanUnpoisonStackMemoryFunc = M.getOrInsertFunction(
2852 kAsanUnpoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
2853 }
2854
2855 for (size_t Val : {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0xf1, 0xf2,
2856 0xf3, 0xf5, 0xf8}) {
2857 std::ostringstream Name;
2859 Name << std::setw(2) << std::setfill('0') << std::hex << Val;
2860 AsanSetShadowFunc[Val] =
2861 M.getOrInsertFunction(Name.str(), IRB.getVoidTy(), IntptrTy, IntptrTy);
2862 }
2863
2864 AsanAllocaPoisonFunc = M.getOrInsertFunction(
2865 kAsanAllocaPoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
2866 AsanAllocasUnpoisonFunc = M.getOrInsertFunction(
2867 kAsanAllocasUnpoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
2868}
2869
2870void FunctionStackPoisoner::copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
2871 ArrayRef<uint8_t> ShadowBytes,
2872 size_t Begin, size_t End,
2873 IRBuilder<> &IRB,
2874 Value *ShadowBase) {
2875 if (Begin >= End)
2876 return;
2877
2878 const size_t LargestStoreSizeInBytes =
2879 std::min<size_t>(sizeof(uint64_t), ASan.LongSize / 8);
2880
2881 const bool IsLittleEndian = F.getParent()->getDataLayout().isLittleEndian();
2882
2883 // Poison given range in shadow using larges store size with out leading and
2884 // trailing zeros in ShadowMask. Zeros never change, so they need neither
2885 // poisoning nor up-poisoning. Still we don't mind if some of them get into a
2886 // middle of a store.
2887 for (size_t i = Begin; i < End;) {
2888 if (!ShadowMask[i]) {
2889 assert(!ShadowBytes[i]);
2890 ++i;
2891 continue;
2892 }
2893
2894 size_t StoreSizeInBytes = LargestStoreSizeInBytes;
2895 // Fit store size into the range.
2896 while (StoreSizeInBytes > End - i)
2897 StoreSizeInBytes /= 2;
2898
2899 // Minimize store size by trimming trailing zeros.
2900 for (size_t j = StoreSizeInBytes - 1; j && !ShadowMask[i + j]; --j) {
2901 while (j <= StoreSizeInBytes / 2)
2902 StoreSizeInBytes /= 2;
2903 }
2904
2905 uint64_t Val = 0;
2906 for (size_t j = 0; j < StoreSizeInBytes; j++) {
2907 if (IsLittleEndian)
2908 Val |= (uint64_t)ShadowBytes[i + j] << (8 * j);
2909 else
2910 Val = (Val << 8) | ShadowBytes[i + j];
2911 }
2912
2913 Value *Ptr = IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i));
2914 Value *Poison = IRB.getIntN(StoreSizeInBytes * 8, Val);
2916 Poison, IRB.CreateIntToPtr(Ptr, Poison->getType()->getPointerTo()),
2917 Align(1));
2918
2919 i += StoreSizeInBytes;
2920 }
2921}
2922
2923void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2924 ArrayRef<uint8_t> ShadowBytes,
2925 IRBuilder<> &IRB, Value *ShadowBase) {
2926 copyToShadow(ShadowMask, ShadowBytes, 0, ShadowMask.size(), IRB, ShadowBase);
2927}
2928
2929void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2930 ArrayRef<uint8_t> ShadowBytes,
2931 size_t Begin, size_t End,
2932 IRBuilder<> &IRB, Value *ShadowBase) {
2933 assert(ShadowMask.size() == ShadowBytes.size());
2934 size_t Done = Begin;
2935 for (size_t i = Begin, j = Begin + 1; i < End; i = j++) {
2936 if (!ShadowMask[i]) {
2937 assert(!ShadowBytes[i]);
2938 continue;
2939 }
2940 uint8_t Val = ShadowBytes[i];
2941 if (!AsanSetShadowFunc[Val])
2942 continue;
2943
2944 // Skip same values.
2945 for (; j < End && ShadowMask[j] && Val == ShadowBytes[j]; ++j) {
2946 }
2947
2948 if (j - i >= ClMaxInlinePoisoningSize) {
2949 copyToShadowInline(ShadowMask, ShadowBytes, Done, i, IRB, ShadowBase);
2950 IRB.CreateCall(AsanSetShadowFunc[Val],
2951 {IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i)),
2952 ConstantInt::get(IntptrTy, j - i)});
2953 Done = j;
2954 }
2955 }
2956
2957 copyToShadowInline(ShadowMask, ShadowBytes, Done, End, IRB, ShadowBase);
2958}
2959
2960// Fake stack allocator (asan_fake_stack.h) has 11 size classes
2961// for every power of 2 from kMinStackMallocSize to kMaxAsanStackMallocSizeClass
2962static int StackMallocSizeClass(uint64_t LocalStackSize) {
2963 assert(LocalStackSize <= kMaxStackMallocSize);
2964 uint64_t MaxSize = kMinStackMallocSize;
2965 for (int i = 0;; i++, MaxSize *= 2)
2966 if (LocalStackSize <= MaxSize) return i;
2967 llvm_unreachable("impossible LocalStackSize");
2968}
2969
2970void FunctionStackPoisoner::copyArgsPassedByValToAllocas() {
2971 Instruction *CopyInsertPoint = &F.front().front();
2972 if (CopyInsertPoint == ASan.LocalDynamicShadow) {
2973 // Insert after the dynamic shadow location is determined
2974 CopyInsertPoint = CopyInsertPoint->getNextNode();
2975 assert(CopyInsertPoint);
2976 }
2977 IRBuilder<> IRB(CopyInsertPoint);
2978 const DataLayout &DL = F.getParent()->getDataLayout();
2979 for (Argument &Arg : F.args()) {
2980 if (Arg.hasByValAttr()) {
2981 Type *Ty = Arg.getParamByValType();
2982 const Align Alignment =
2983 DL.getValueOrABITypeAlignment(Arg.getParamAlign(), Ty);
2984
2985 AllocaInst *AI = IRB.CreateAlloca(
2986 Ty, nullptr,
2987 (Arg.hasName() ? Arg.getName() : "Arg" + Twine(Arg.getArgNo())) +
2988 ".byval");
2989 AI->setAlignment(Alignment);
2990 Arg.replaceAllUsesWith(AI);
2991
2992 uint64_t AllocSize = DL.getTypeAllocSize(Ty);
2993 IRB.CreateMemCpy(AI, Alignment, &Arg, Alignment, AllocSize);
2994 }
2995 }
2996}
2997
2998PHINode *FunctionStackPoisoner::createPHI(IRBuilder<> &IRB, Value *Cond,
2999 Value *ValueIfTrue,
3000 Instruction *ThenTerm,
3001 Value *ValueIfFalse) {
3002 PHINode *PHI = IRB.CreatePHI(IntptrTy, 2);
3003 BasicBlock *CondBlock = cast<Instruction>(Cond)->getParent();
3004 PHI->addIncoming(ValueIfFalse, CondBlock);
3005 BasicBlock *ThenBlock = ThenTerm->getParent();
3006 PHI->addIncoming(ValueIfTrue, ThenBlock);
3007 return PHI;
3008}
3009
3010Value *FunctionStackPoisoner::createAllocaForLayout(
3011 IRBuilder<> &IRB, const ASanStackFrameLayout &L, bool Dynamic) {
3012 AllocaInst *Alloca;
3013 if (Dynamic) {
3014 Alloca = IRB.CreateAlloca(IRB.getInt8Ty(),
3016 "MyAlloca");
3017 } else {
3018 Alloca = IRB.CreateAlloca(ArrayType::get(IRB.getInt8Ty(), L.FrameSize),
3019 nullptr, "MyAlloca");
3020 assert(Alloca->isStaticAlloca());
3021 }
3022 assert((ClRealignStack & (ClRealignStack - 1)) == 0);
3023 uint64_t FrameAlignment = std::max(L.FrameAlignment, uint64_t(ClRealignStack));
3024 Alloca->setAlignment(Align(FrameAlignment));
3025 return IRB.CreatePointerCast(Alloca, IntptrTy);
3026}
3027
3028void FunctionStackPoisoner::createDynamicAllocasInitStorage() {
3029 BasicBlock &FirstBB = *F.begin();
3030 IRBuilder<> IRB(dyn_cast<Instruction>(FirstBB.begin()));
3031 DynamicAllocaLayout = IRB.CreateAlloca(IntptrTy, nullptr);
3032 IRB.CreateStore(Constant::getNullValue(IntptrTy), DynamicAllocaLayout);
3033 DynamicAllocaLayout->setAlignment(Align(32));
3034}
3035
3036void FunctionStackPoisoner::processDynamicAllocas() {
3037 if (!ClInstrumentDynamicAllocas || DynamicAllocaVec.empty()) {
3038 assert(DynamicAllocaPoisonCallVec.empty());
3039 return;
3040 }
3041
3042 // Insert poison calls for lifetime intrinsics for dynamic allocas.
3043 for (const auto &APC : DynamicAllocaPoisonCallVec) {
3044 assert(APC.InsBefore);
3045 assert(APC.AI);
3046 assert(ASan.isInterestingAlloca(*APC.AI));
3047 assert(!APC.AI->isStaticAlloca());
3048
3049 IRBuilder<> IRB(APC.InsBefore);
3050 poisonAlloca(APC.AI, APC.Size, IRB, APC.DoPoison);
3051 // Dynamic allocas will be unpoisoned unconditionally below in
3052 // unpoisonDynamicAllocas.
3053 // Flag that we need unpoison static allocas.
3054 }
3055
3056 // Handle dynamic allocas.
3057 createDynamicAllocasInitStorage();
3058 for (auto &AI : DynamicAllocaVec)
3059 handleDynamicAllocaCall(AI);
3060 unpoisonDynamicAllocas();
3061}
3062
3063/// Collect instructions in the entry block after \p InsBefore which initialize
3064/// permanent storage for a function argument. These instructions must remain in
3065/// the entry block so that uninitialized values do not appear in backtraces. An
3066/// added benefit is that this conserves spill slots. This does not move stores
3067/// before instrumented / "interesting" allocas.
3069 AddressSanitizer &ASan, Instruction &InsBefore,
3070 SmallVectorImpl<Instruction *> &InitInsts) {
3071 Instruction *Start = InsBefore.getNextNonDebugInstruction();
3072 for (Instruction *It = Start; It; It = It->getNextNonDebugInstruction()) {
3073 // Argument initialization looks like:
3074 // 1) store <Argument>, <Alloca> OR
3075 // 2) <CastArgument> = cast <Argument> to ...
3076 // store <CastArgument> to <Alloca>
3077 // Do not consider any other kind of instruction.
3078 //
3079 // Note: This covers all known cases, but may not be exhaustive. An
3080 // alternative to pattern-matching stores is to DFS over all Argument uses:
3081 // this might be more general, but is probably much more complicated.
3082 if (isa<AllocaInst>(It) || isa<CastInst>(It))
3083 continue;
3084 if (auto *Store = dyn_cast<StoreInst>(It)) {
3085 // The store destination must be an alloca that isn't interesting for
3086 // ASan to instrument. These are moved up before InsBefore, and they're
3087 // not interesting because allocas for arguments can be mem2reg'd.
3088 auto *Alloca = dyn_cast<AllocaInst>(Store->getPointerOperand());
3089 if (!Alloca || ASan.isInterestingAlloca(*Alloca))
3090 continue;
3091
3092 Value *Val = Store->getValueOperand();
3093 bool IsDirectArgInit = isa<Argument>(Val);
3094 bool IsArgInitViaCast =
3095 isa<CastInst>(Val) &&
3096 isa<Argument>(cast<CastInst>(Val)->getOperand(0)) &&
3097 // Check that the cast appears directly before the store. Otherwise
3098 // moving the cast before InsBefore may break the IR.
3099 Val == It->getPrevNonDebugInstruction();
3100 bool IsArgInit = IsDirectArgInit || IsArgInitViaCast;
3101 if (!IsArgInit)
3102 continue;
3103
3104 if (IsArgInitViaCast)
3105 InitInsts.push_back(cast<Instruction>(Val));
3106 InitInsts.push_back(Store);
3107 continue;
3108 }
3109
3110 // Do not reorder past unknown instructions: argument initialization should
3111 // only involve casts and stores.
3112 return;
3113 }
3114}
3115
3116void FunctionStackPoisoner::processStaticAllocas() {
3117 if (AllocaVec.empty()) {
3118 assert(StaticAllocaPoisonCallVec.empty());
3119 return;
3120 }
3121
3122 int StackMallocIdx = -1;
3123 DebugLoc EntryDebugLocation;
3124 if (auto SP = F.getSubprogram())
3125 EntryDebugLocation =
3126 DILocation::get(SP->getContext(), SP->getScopeLine(), 0, SP);
3127
3128 Instruction *InsBefore = AllocaVec[0];
3129 IRBuilder<> IRB(InsBefore);
3130
3131 // Make sure non-instrumented allocas stay in the entry block. Otherwise,
3132 // debug info is broken, because only entry-block allocas are treated as
3133 // regular stack slots.
3134 auto InsBeforeB = InsBefore->getParent();
3135 assert(InsBeforeB == &F.getEntryBlock());
3136 for (auto *AI : StaticAllocasToMoveUp)
3137 if (AI->getParent() == InsBeforeB)
3138 AI->moveBefore(InsBefore);
3139
3140 // Move stores of arguments into entry-block allocas as well. This prevents
3141 // extra stack slots from being generated (to house the argument values until
3142 // they can be stored into the allocas). This also prevents uninitialized
3143 // values from being shown in backtraces.
3144 SmallVector<Instruction *, 8> ArgInitInsts;
3145 findStoresToUninstrumentedArgAllocas(ASan, *InsBefore, ArgInitInsts);
3146 for (Instruction *ArgInitInst : ArgInitInsts)
3147 ArgInitInst->moveBefore(InsBefore);
3148
3149 // If we have a call to llvm.localescape, keep it in the entry block.
3150 if (LocalEscapeCall) LocalEscapeCall->moveBefore(InsBefore);
3151
3153 SVD.reserve(AllocaVec.size());
3154 for (AllocaInst *AI : AllocaVec) {
3156 ASan.getAllocaSizeInBytes(*AI),
3157 0,
3158 AI->getAlign().value(),
3159 AI,
3160 0,
3161 0};
3162 SVD.push_back(D);
3163 }
3164
3165 // Minimal header size (left redzone) is 4 pointers,
3166 // i.e. 32 bytes on 64-bit platforms and 16 bytes in 32-bit platforms.
3167 uint64_t Granularity = 1ULL << Mapping.Scale;
3168 uint64_t MinHeaderSize = std::max((uint64_t)ASan.LongSize / 2, Granularity);
3169 const ASanStackFrameLayout &L =
3170 ComputeASanStackFrameLayout(SVD, Granularity, MinHeaderSize);
3171
3172 // Build AllocaToSVDMap for ASanStackVariableDescription lookup.
3174 for (auto &Desc : SVD)
3175 AllocaToSVDMap[Desc.AI] = &Desc;
3176
3177 // Update SVD with information from lifetime intrinsics.
3178 for (const auto &APC : StaticAllocaPoisonCallVec) {
3179 assert(APC.InsBefore);
3180 assert(APC.AI);
3181 assert(ASan.isInterestingAlloca(*APC.AI));
3182 assert(APC.AI->isStaticAlloca());
3183
3184 ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
3185 Desc.LifetimeSize = Desc.Size;
3186 if (const DILocation *FnLoc = EntryDebugLocation.get()) {
3187 if (const DILocation *LifetimeLoc = APC.InsBefore->getDebugLoc().get()) {
3188 if (LifetimeLoc->getFile() == FnLoc->getFile())
3189 if (unsigned Line = LifetimeLoc->getLine())
3190 Desc.Line = std::min(Desc.Line ? Desc.Line : Line, Line);
3191 }
3192 }
3193 }
3194
3195 auto DescriptionString = ComputeASanStackFrameDescription(SVD);
3196 LLVM_DEBUG(dbgs() << DescriptionString << " --- " << L.FrameSize << "\n");
3197 uint64_t LocalStackSize = L.FrameSize;
3198 bool DoStackMalloc =
3199 ASan.UseAfterReturn != AsanDetectStackUseAfterReturnMode::Never &&
3200 !ASan.CompileKernel && LocalStackSize <= kMaxStackMallocSize;
3201 bool DoDynamicAlloca = ClDynamicAllocaStack;
3202 // Don't do dynamic alloca or stack malloc if:
3203 // 1) There is inline asm: too often it makes assumptions on which registers
3204 // are available.
3205 // 2) There is a returns_twice call (typically setjmp), which is
3206 // optimization-hostile, and doesn't play well with introduced indirect
3207 // register-relative calculation of local variable addresses.
3208 DoDynamicAlloca &= !HasInlineAsm && !HasReturnsTwiceCall;
3209 DoStackMalloc &= !HasInlineAsm && !HasReturnsTwiceCall;
3210
3211 Value *StaticAlloca =
3212 DoDynamicAlloca ? nullptr : createAllocaForLayout(IRB, L, false);
3213
3214 Value *FakeStack;
3215 Value *LocalStackBase;
3216 Value *LocalStackBaseAlloca;
3217 uint8_t DIExprFlags = DIExpression::ApplyOffset;
3218
3219 if (DoStackMalloc) {
3220 LocalStackBaseAlloca =
3221 IRB.CreateAlloca(IntptrTy, nullptr, "asan_local_stack_base");
3222 if (ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Runtime) {
3223 // void *FakeStack = __asan_option_detect_stack_use_after_return
3224 // ? __asan_stack_malloc_N(LocalStackSize)
3225 // : nullptr;
3226 // void *LocalStackBase = (FakeStack) ? FakeStack :
3227 // alloca(LocalStackSize);
3228 Constant *OptionDetectUseAfterReturn = F.getParent()->getOrInsertGlobal(
3230 Value *UseAfterReturnIsEnabled = IRB.CreateICmpNE(
3231 IRB.CreateLoad(IRB.getInt32Ty(), OptionDetectUseAfterReturn),
3233 Instruction *Term =
3234 SplitBlockAndInsertIfThen(UseAfterReturnIsEnabled, InsBefore, false);
3235 IRBuilder<> IRBIf(Term);
3236 StackMallocIdx = StackMallocSizeClass(LocalStackSize);
3237 assert(StackMallocIdx <= kMaxAsanStackMallocSizeClass);
3238 Value *FakeStackValue =
3239 IRBIf.CreateCall(AsanStackMallocFunc[StackMallocIdx],
3240 ConstantInt::get(IntptrTy, LocalStackSize));
3241 IRB.SetInsertPoint(InsBefore);
3242 FakeStack = createPHI(IRB, UseAfterReturnIsEnabled, FakeStackValue, Term,
3243 ConstantInt::get(IntptrTy, 0));
3244 } else {
3245 // assert(ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode:Always)
3246 // void *FakeStack = __asan_stack_malloc_N(LocalStackSize);
3247 // void *LocalStackBase = (FakeStack) ? FakeStack :
3248 // alloca(LocalStackSize);
3249 StackMallocIdx = StackMallocSizeClass(LocalStackSize);
3250 FakeStack = IRB.CreateCall(AsanStackMallocFunc[StackMallocIdx],
3251 ConstantInt::get(IntptrTy, LocalStackSize));
3252 }
3253 Value *NoFakeStack =
3254 IRB.CreateICmpEQ(FakeStack, Constant::getNullValue(IntptrTy));
3255 Instruction *Term =
3256 SplitBlockAndInsertIfThen(NoFakeStack, InsBefore, false);
3257 IRBuilder<> IRBIf(Term);
3258 Value *AllocaValue =
3259 DoDynamicAlloca ? createAllocaForLayout(IRBIf, L, true) : StaticAlloca;
3260
3261 IRB.SetInsertPoint(InsBefore);
3262 LocalStackBase = createPHI(IRB, NoFakeStack, AllocaValue, Term, FakeStack);
3263 IRB.CreateStore(LocalStackBase, LocalStackBaseAlloca);
3264 DIExprFlags |= DIExpression::DerefBefore;
3265 } else {
3266 // void *FakeStack = nullptr;
3267 // void *LocalStackBase = alloca(LocalStackSize);
3268 FakeStack = ConstantInt::get(IntptrTy, 0);
3269 LocalStackBase =
3270 DoDynamicAlloca ? createAllocaForLayout(IRB, L, true) : StaticAlloca;
3271 LocalStackBaseAlloca = LocalStackBase;
3272 }
3273
3274 // It shouldn't matter whether we pass an `alloca` or a `ptrtoint` as the
3275 // dbg.declare address opereand, but passing a `ptrtoint` seems to confuse
3276 // later passes and can result in dropped variable coverage in debug info.
3277 Value *LocalStackBaseAllocaPtr =
3278 isa<PtrToIntInst>(LocalStackBaseAlloca)
3279 ? cast<PtrToIntInst>(LocalStackBaseAlloca)->getPointerOperand()
3280 : LocalStackBaseAlloca;
3281 assert(isa<AllocaInst>(LocalStackBaseAllocaPtr) &&
3282 "Variable descriptions relative to ASan stack base will be dropped");
3283
3284 // Replace Alloca instructions with base+offset.
3285 for (const auto &Desc : SVD) {
3286 AllocaInst *AI = Desc.AI;
3287 replaceDbgDeclare(AI, LocalStackBaseAllocaPtr, DIB, DIExprFlags,
3288 Desc.Offset);
3289 Value *NewAllocaPtr = IRB.CreateIntToPtr(
3290 IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Desc.Offset)),
3291 AI->getType());
3292 AI->replaceAllUsesWith(NewAllocaPtr);
3293 }
3294
3295 // The left-most redzone has enough space for at least 4 pointers.
3296 // Write the Magic value to redzone[0].
3297 Value *BasePlus0 = IRB.CreateIntToPtr(LocalStackBase, IntptrPtrTy);
3299 BasePlus0);
3300 // Write the frame description constant to redzone[1].
3301 Value *BasePlus1 = IRB.CreateIntToPtr(
3302 IRB.CreateAdd(LocalStackBase,
3303 ConstantInt::get(IntptrTy, ASan.LongSize / 8)),
3304 IntptrPtrTy);
3305 GlobalVariable *StackDescriptionGlobal =
3306 createPrivateGlobalForString(*F.getParent(), DescriptionString,
3307 /*AllowMerging*/ true, kAsanGenPrefix);
3308 Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal, IntptrTy);
3309 IRB.CreateStore(Description, BasePlus1);
3310 // Write the PC to redzone[2].
3311 Value *BasePlus2 = IRB.CreateIntToPtr(
3312 IRB.CreateAdd(LocalStackBase,
3313 ConstantInt::get(IntptrTy, 2 * ASan.LongSize / 8)),
3314 IntptrPtrTy);
3315 IRB.CreateStore(IRB.CreatePointerCast(&F, IntptrTy), BasePlus2);
3316
3317 const auto &ShadowAfterScope = GetShadowBytesAfterScope(SVD, L);
3318
3319 // Poison the stack red zones at the entry.
3320 Value *ShadowBase = ASan.memToShadow(LocalStackBase, IRB);
3321 // As mask we must use most poisoned case: red zones and after scope.
3322 // As bytes we can use either the same or just red zones only.
3323 copyToShadow(ShadowAfterScope, ShadowAfterScope, IRB, ShadowBase);
3324
3325 if (!StaticAllocaPoisonCallVec.empty()) {
3326 const auto &ShadowInScope = GetShadowBytes(SVD, L);
3327
3328 // Poison static allocas near lifetime intrinsics.
3329 for (const auto &APC : StaticAllocaPoisonCallVec) {
3330 const ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
3331 assert(Desc.Offset % L.Granularity == 0);
3332 size_t Begin = Desc.Offset / L.Granularity;
3333 size_t End = Begin + (APC.Size + L.Granularity - 1) / L.Granularity;
3334
3335 IRBuilder<> IRB(APC.InsBefore);
3336 copyToShadow(ShadowAfterScope,
3337 APC.DoPoison ? ShadowAfterScope : ShadowInScope, Begin, End,
3338 IRB, ShadowBase);
3339 }
3340 }
3341
3342 SmallVector<uint8_t, 64> ShadowClean(ShadowAfterScope.size(), 0);
3343 SmallVector<uint8_t, 64> ShadowAfterReturn;
3344
3345 // (Un)poison the stack before all ret instructions.
3346 for (Instruction *Ret : RetVec) {
3347 IRBuilder<> IRBRet(Ret);
3348 // Mark the current frame as retired.
3349 IRBRet.CreateStore(ConstantInt::get(IntptrTy, kRetiredStackFrameMagic),
3350 BasePlus0);
3351 if (DoStackMalloc) {
3352 assert(StackMallocIdx >= 0);
3353 // if FakeStack != 0 // LocalStackBase == FakeStack
3354 // // In use-after-return mode, poison the whole stack frame.
3355 // if StackMallocIdx <= 4
3356 // // For small sizes inline the whole thing:
3357 // memset(ShadowBase, kAsanStackAfterReturnMagic, ShadowSize);
3358 // **SavedFlagPtr(FakeStack) = 0
3359 // else
3360 // __asan_stack_free_N(FakeStack, LocalStackSize)
3361 // else
3362 // <This is not a fake stack; unpoison the redzones>
3363 Value *Cmp =
3364 IRBRet.CreateICmpNE(FakeStack, Constant::getNullValue(IntptrTy));
3365 Instruction *ThenTerm, *ElseTerm;
3366 SplitBlockAndInsertIfThenElse(Cmp, Ret, &ThenTerm, &ElseTerm);
3367
3368 IRBuilder<> IRBPoison(ThenTerm);
3369 if (StackMallocIdx <= 4) {
3370 int ClassSize = kMinStackMallocSize << StackMallocIdx;
3371 ShadowAfterReturn.resize(ClassSize / L.Granularity,
3373 copyToShadow(ShadowAfterReturn, ShadowAfterReturn, IRBPoison,
3374 ShadowBase);
3375 Value *SavedFlagPtrPtr = IRBPoison.CreateAdd(
3376 FakeStack,
3377 ConstantInt::get(IntptrTy, ClassSize - ASan.LongSize / 8));
3378 Value *SavedFlagPtr = IRBPoison.CreateLoad(
3379 IntptrTy, IRBPoison.CreateIntToPtr(SavedFlagPtrPtr, IntptrPtrTy));
3380 IRBPoison.CreateStore(
3381 Constant::getNullValue(IRBPoison.getInt8Ty()),
3382 IRBPoison.CreateIntToPtr(SavedFlagPtr, IRBPoison.getInt8PtrTy()));
3383 } else {
3384 // For larger frames call __asan_stack_free_*.
3385 IRBPoison.CreateCall(
3386 AsanStackFreeFunc[StackMallocIdx],
3387 {FakeStack, ConstantInt::get(IntptrTy, LocalStackSize)});
3388 }
3389
3390 IRBuilder<> IRBElse(ElseTerm);
3391 copyToShadow(ShadowAfterScope, ShadowClean, IRBElse, ShadowBase);
3392 } else {
3393 copyToShadow(ShadowAfterScope, ShadowClean, IRBRet, ShadowBase);
3394 }
3395 }
3396
3397 // We are done. Remove the old unused alloca instructions.
3398 for (auto *AI : AllocaVec)
3399 AI->eraseFromParent();
3400}
3401
3402void FunctionStackPoisoner::poisonAlloca(Value *V, uint64_t Size,
3403 IRBuilder<> &IRB, bool DoPoison) {
3404 // For now just insert the call to ASan runtime.
3405 Value *AddrArg = IRB.CreatePointerCast(V, IntptrTy);
3406 Value *SizeArg = ConstantInt::get(IntptrTy, Size);
3407 IRB.CreateCall(
3408 DoPoison ? AsanPoisonStackMemoryFunc : AsanUnpoisonStackMemoryFunc,
3409 {AddrArg, SizeArg});
3410}
3411
3412// Handling llvm.lifetime intrinsics for a given %alloca:
3413// (1) collect all llvm.lifetime.xxx(%size, %value) describing the alloca.
3414// (2) if %size is constant, poison memory for llvm.lifetime.end (to detect
3415// invalid accesses) and unpoison it for llvm.lifetime.start (the memory
3416// could be poisoned by previous llvm.lifetime.end instruction, as the
3417// variable may go in and out of scope several times, e.g. in loops).
3418// (3) if we poisoned at least one %alloca in a function,
3419// unpoison the whole stack frame at function exit.
3420void FunctionStackPoisoner::handleDynamicAllocaCall(AllocaInst *AI) {
3421 IRBuilder<> IRB(AI);
3422
3423 const Align Alignment = std::max(Align(kAllocaRzSize), AI->getAlign());
3424 const uint64_t AllocaRedzoneMask = kAllocaRzSize - 1;
3425
3426 Value *Zero = Constant::getNullValue(IntptrTy);
3427 Value *AllocaRzSize = ConstantInt::get(IntptrTy, kAllocaRzSize);
3428 Value *AllocaRzMask = ConstantInt::get(IntptrTy, AllocaRedzoneMask);
3429
3430 // Since we need to extend alloca with additional memory to locate
3431 // redzones, and OldSize is number of allocated blocks with
3432 // ElementSize size, get allocated memory size in bytes by
3433 // OldSize * ElementSize.
3434 const unsigned ElementSize =
3435 F.getParent()->getDataLayout().getTypeAllocSize(AI->getAllocatedType());
3436 Value *OldSize =
3437 IRB.CreateMul(IRB.CreateIntCast(AI->getArraySize(), IntptrTy, false),
3438 ConstantInt::get(IntptrTy, ElementSize));
3439
3440 // PartialSize = OldSize % 32
3441 Value *PartialSize = IRB.CreateAnd(OldSize, AllocaRzMask);
3442
3443 // Misalign = kAllocaRzSize - PartialSize;
3444 Value *Misalign = IRB.CreateSub(AllocaRzSize, PartialSize);
3445
3446 // PartialPadding = Misalign != kAllocaRzSize ? Misalign : 0;
3447 Value *Cond = IRB.CreateICmpNE(Misalign, AllocaRzSize);
3448 Value *PartialPadding = IRB.CreateSelect(Cond, Misalign, Zero);
3449
3450 // AdditionalChunkSize = Alignment + PartialPadding + kAllocaRzSize
3451 // Alignment is added to locate left redzone, PartialPadding for possible
3452 // partial redzone and kAllocaRzSize for right redzone respectively.
3453 Value *AdditionalChunkSize = IRB.CreateAdd(
3454 ConstantInt::get(IntptrTy, Alignment.value() + kAllocaRzSize),
3455 PartialPadding);
3456
3457 Value *NewSize = IRB.CreateAdd(OldSize, AdditionalChunkSize);
3458
3459 // Insert new alloca with new NewSize and Alignment params.
3460 AllocaInst *NewAlloca = IRB.CreateAlloca(IRB.getInt8Ty(), NewSize);
3461 NewAlloca->setAlignment(Alignment);
3462
3463 // NewAddress = Address + Alignment
3464 Value *NewAddress =
3465 IRB.CreateAdd(IRB.CreatePtrToInt(NewAlloca, IntptrTy),
3466 ConstantInt::get(IntptrTy, Alignment.value()));
3467
3468 // Insert __asan_alloca_poison call for new created alloca.
3469 IRB.CreateCall(AsanAllocaPoisonFunc, {NewAddress, OldSize});
3470
3471 // Store the last alloca's address to DynamicAllocaLayout. We'll need this
3472 // for unpoisoning stuff.
3473 IRB.CreateStore(IRB.CreatePtrToInt(NewAlloca, IntptrTy), DynamicAllocaLayout);
3474
3475 Value *NewAddressPtr = IRB.CreateIntToPtr(NewAddress, AI->getType());
3476
3477 // Replace all uses of AddessReturnedByAlloca with NewAddressPtr.
3478 AI->replaceAllUsesWith(NewAddressPtr);
3479
3480 // We are done. Erase old alloca from parent.
3481 AI->eraseFromParent();
3482}
3483
3484// isSafeAccess returns true if Addr is always inbounds with respect to its
3485// base object. For example, it is a field access or an array access with
3486// constant inbounds index.
3487bool AddressSanitizer::isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis,
3488 Value *Addr, uint64_t TypeSize) const {
3489 SizeOffsetType SizeOffset = ObjSizeVis.compute(Addr);
3490 if (!ObjSizeVis.bothKnown(SizeOffset)) return false;
3491 uint64_t Size = SizeOffset.first.getZExtValue();
3492 int64_t Offset = SizeOffset.second.getSExtValue();
3493 // Three checks are required to ensure safety:
3494 // . Offset >= 0 (since the offset is given from the base ptr)
3495 // . Size >= Offset (unsigned)
3496 // . Size - Offset >= NeededSize (unsigned)
3497 return Offset >= 0 && Size >= uint64_t(Offset) &&
3498 Size - uint64_t(Offset) >= TypeSize / 8;
3499}
MachineBasicBlock MachineBasicBlock::iterator DebugLoc DL
static cl::opt< bool > ClUseStackSafety("stack-tagging-use-stack-safety", cl::Hidden, cl::init(true), cl::desc("Use Stack Safety analysis results"))
This header is deprecated in favour of llvm/TargetParser/Triple.h.
amdgpu Simplify well known AMD library false FunctionCallee Value * Arg
Rewrite undef for PHI
static void findStoresToUninstrumentedArgAllocas(AddressSanitizer &ASan, Instruction &InsBefore, SmallVectorImpl< Instruction * > &InitInsts)
Collect instructions in the entry block after InsBefore which initialize permanent storage for a func...
static const uint64_t kDefaultShadowScale
constexpr size_t kAccessSizeIndexMask
static size_t TypeSizeToSizeIndex(uint32_t TypeSize)
static cl::opt< int > ClDebugMin("asan-debug-min", cl::desc("Debug min inst"), cl::Hidden, cl::init(-1))
static cl::opt< bool > ClUsePrivateAlias("asan-use-private-alias", cl::desc("Use private aliases for global variables"), cl::Hidden, cl::init(true))
static const uint64_t kPS_ShadowOffset64
static const uint64_t kFreeBSD_ShadowOffset32
constexpr size_t kIsWriteShift
static const uint64_t kSmallX86_64ShadowOffsetAlignMask
static bool isInterestingPointerSubtraction(Instruction *I)
const char kAMDGPUAddressSharedName[]
const char kAsanStackFreeNameTemplate[]
constexpr size_t kCompileKernelMask
static cl::opt< bool > ClForceDynamicShadow("asan-force-dynamic-shadow", cl::desc("Load shadow address into a local variable for each function"), cl::Hidden, cl::init(false))
const char kAsanOptionDetectUseAfterReturn[]
static cl::opt< std::string > ClMemoryAccessCallbackPrefix("asan-memory-access-callback-prefix", cl::desc("Prefix for memory access callbacks"), cl::Hidden, cl::init("__asan_"))
static const uint64_t kRISCV64_ShadowOffset64
static cl::opt< bool > ClInsertVersionCheck("asan-guard-against-version-mismatch", cl::desc("Guard against compiler/runtime version mismatch."), cl::Hidden, cl::init(true))
const char kAsanSetShadowPrefix[]
static cl::opt< AsanDtorKind > ClOverrideDestructorKind("asan-destructor-kind", cl::desc("Sets the ASan destructor kind. The default is to use the value " "provided to the pass constructor"), cl::values(clEnumValN(AsanDtorKind::None, "none", "No destructors"), clEnumValN(AsanDtorKind::Global, "global", "Use global destructors")), cl::init(AsanDtorKind::Invalid), cl::Hidden)
static cl::opt< bool > ClInstrumentWrites("asan-instrument-writes", cl::desc("instrument write instructions"), cl::Hidden, cl::init(true))
const char kAsanPtrCmp[]
static uint64_t GetCtorAndDtorPriority(Triple &TargetTriple)
const char kAsanStackMallocNameTemplate[]
static cl::opt< bool > ClInstrumentByval("asan-instrument-byval", cl::desc("instrument byval call arguments"), cl::Hidden, cl::init(true))
const char kAsanInitName[]
static cl::opt< bool > ClGlobals("asan-globals", cl::desc("Handle global objects"), cl::Hidden, cl::init(true))
static cl::opt< bool > ClRedzoneByvalArgs("asan-redzone-byval-args", cl::desc("Create redzones for byval " "arguments (extra copy " "required)"), cl::Hidden, cl::init(true))
static const uint64_t kWindowsShadowOffset64
static const uint64_t kEmscriptenShadowOffset
const char kAsanGenPrefix[]
constexpr size_t kIsWriteMask
static uint64_t getRedzoneSizeForScale(int MappingScale)
static const uint64_t kDefaultShadowOffset64
static cl::opt< bool > ClOptimizeCallbacks("asan-optimize-callbacks", cl::desc("Optimize callbacks"), cl::Hidden, cl::init(false))
const char kAsanUnregisterGlobalsName[]
static const uint64_t kAsanCtorAndDtorPriority
static cl::opt< bool > ClUseStackSafety("asan-use-stack-safety", cl::Hidden, cl::init(false), cl::Hidden, cl::desc("Use Stack Safety analysis results"), cl::Optional)
const char kAsanUnpoisonGlobalsName[]
static cl::opt< bool > ClWithIfuncSuppressRemat("asan-with-ifunc-suppress-remat", cl::desc("Suppress rematerialization of dynamic shadow address by passing " "it through inline asm in prologue."), cl::Hidden, cl::init(true))
static cl::opt< int > ClDebugStack("asan-debug-stack", cl::desc("debug stack"), cl::Hidden, cl::init(0))
const char kAsanUnregisterElfGlobalsName[]
static bool isUnsupportedAMDGPUAddrspace(Value *Addr)
const char kAsanRegisterImageGlobalsName[]
static cl::opt< bool > ClOpt("asan-opt", cl::desc("Optimize instrumentation"), cl::Hidden, cl::init(true))
static const uint64_t kAllocaRzSize
const char kODRGenPrefix[]
static const uint64_t kSystemZ_ShadowOffset64
static const uint64_t kDefaultShadowOffset32
const char kAsanShadowMemoryDynamicAddress[]
static cl::opt< bool > ClUseOdrIndicator("asan-use-odr-indicator", cl::desc("Use odr indicators to improve ODR reporting"), cl::Hidden, cl::init(true))
static bool GlobalWasGeneratedByCompiler(GlobalVariable *G)
Check if G has been created by a trusted compiler pass.
const char kAsanStackMallocAlwaysNameTemplate[]
static cl::opt< bool > ClInvalidPointerCmp("asan-detect-invalid-pointer-cmp", cl::desc("Instrument <, <=, >, >= with pointer operands"), cl::Hidden, cl::init(false))
static const uint64_t kAsanEmscriptenCtorAndDtorPriority
static cl::opt< int > ClDebugMax("asan-debug-max", cl::desc("Debug max inst"), cl::Hidden, cl::init(-1))
static cl::opt< bool > ClInvalidPointerSub("asan-detect-invalid-pointer-sub", cl::desc("Instrument - operations with pointer operands"), cl::Hidden, cl::init(false))
static bool isPointerOperand(Value *V)
static const uint64_t kFreeBSD_ShadowOffset64
static cl::opt< uint32_t > ClForceExperiment("asan-force-experiment", cl::desc("Force optimization experiment (for testing)"), cl::Hidden, cl::init(0))
const char kSanCovGenPrefix[]
static const uint64_t kFreeBSDKasan_ShadowOffset64
const char kAsanModuleDtorName[]
static const uint64_t kDynamicShadowSentinel
static bool isInterestingPointerComparison(Instruction *I)
static cl::opt< bool > ClStack("asan-stack", cl::desc("Handle stack memory"), cl::Hidden, cl::init(true))
static const uint64_t kMIPS64_ShadowOffset64
static const uint64_t kLinuxKasan_ShadowOffset64
static int StackMallocSizeClass(uint64_t LocalStackSize)
static cl::opt< uint32_t > ClMaxInlinePoisoningSize("asan-max-inline-poisoning-size", cl::desc("Inline shadow poisoning for blocks up to the given size in bytes."), cl::Hidden, cl::init(64))
static cl::opt< bool > ClInstrumentAtomics("asan-instrument-atomics", cl::desc("instrument atomic instructions (rmw, cmpxchg)"), cl::Hidden, cl::init(true))
static cl::opt< bool > ClUseAfterScope("asan-use-after-scope", cl::desc("Check stack-use-after-scope"), cl::Hidden, cl::init(false))
constexpr size_t kAccessSizeIndexShift
static cl::opt< int > ClMappingScale("asan-mapping-scale", cl::desc("scale of asan shadow mapping"), cl::Hidden, cl::init(0))
const char kAsanPoisonStackMemoryName[]
static cl::opt< bool > ClEnableKasan("asan-kernel", cl::desc("Enable KernelAddressSanitizer instrumentation"), cl::Hidden, cl::init(false))
static cl::opt< std::string > ClDebugFunc("asan-debug-func", cl::Hidden, cl::desc("Debug func"))
static cl::opt< bool > ClUseGlobalsGC("asan-globals-live-support", cl::desc("Use linker features to support dead " "code stripping of globals"), cl::Hidden, cl::init(true))
static const size_t kNumberOfAccessSizes
const char kAsanUnpoisonStackMemoryName[]
static const uint64_t kLoongArch64_ShadowOffset64
static void doInstrumentAddress(AddressSanitizer *Pass, Instruction *I, Instruction *InsertBefore, Value *Addr, MaybeAlign Alignment, unsigned Granularity, uint32_t TypeSize, bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp)
const char kAsanRegisterGlobalsName[]
static cl::opt< bool > ClInstrumentDynamicAllocas("asan-instrument-dynamic-allocas", cl::desc("instrument dynamic allocas"), cl::Hidden, cl::init(true))
const char kAsanModuleCtorName[]
const char kAsanGlobalsRegisteredFlagName[]
static const size_t kMaxStackMallocSize
static cl::opt< bool > ClRecover("asan-recover", cl::desc("Enable recovery mode (continue-after-error)."), cl::Hidden, cl::init(false))
static cl::opt< bool > ClOptSameTemp("asan-opt-same-temp", cl::desc("Instrument the same temp just once"), cl::Hidden, cl::init(true))
static cl::opt< bool > ClDynamicAllocaStack("asan-stack-dynamic-alloca", cl::desc("Use dynamic alloca to represent stack variables"), cl::Hidden, cl::init(true))
static cl::opt< bool > ClOptStack("asan-opt-stack", cl::desc("Don't instrument scalar stack variables"), cl::Hidden, cl::init(false))
static const uint64_t kMIPS_ShadowOffsetN32
const char kAsanUnregisterImageGlobalsName[]
static cl::opt< AsanDetectStackUseAfterReturnMode > ClUseAfterReturn("asan-use-after-return", cl::desc("Sets the mode of detection for stack-use-after-return."), cl::values(clEnumValN(AsanDetectStackUseAfterReturnMode::Never, "never", "Never detect stack use after return."), clEnumValN(AsanDetectStackUseAfterReturnMode::Runtime, "runtime", "Detect stack use after return if " "binary flag 'ASAN_OPTIONS=detect_stack_use_after_return' is set."), clEnumValN(AsanDetectStackUseAfterReturnMode::Always, "always", "Always detect stack use after return.")), cl::Hidden, cl::init(AsanDetectStackUseAfterReturnMode::Runtime))
static cl::opt< bool > ClOptGlobals("asan-opt-globals", cl::desc("Don't instrument scalar globals"), cl::Hidden, cl::init(true))
static const uintptr_t kCurrentStackFrameMagic
static cl::opt< int > ClInstrumentationWithCallsThreshold("asan-instrumentation-with-call-threshold", cl::desc("If the function being instrumented contains more than " "this number of memory accesses, use callbacks instead of " "inline checks (-1 means never use callbacks)."), cl::Hidden, cl::init(7000))
static ShadowMapping getShadowMapping(const Triple &TargetTriple, int LongSize, bool IsKasan)
static const uint64_t kPPC64_ShadowOffset64
static cl::opt< AsanCtorKind > ClConstructorKind("asan-constructor-kind", cl::desc("Sets the ASan constructor kind"), cl::values(clEnumValN(AsanCtorKind::None, "none", "No constructors"), clEnumValN(AsanCtorKind::Global, "global", "Use global constructors")), cl::init(AsanCtorKind::Global), cl::Hidden)
static const int kMaxAsanStackMallocSizeClass
static const uint64_t kMIPS32_ShadowOffset32
static cl::opt< bool > ClAlwaysSlowPath("asan-always-slow-path", cl::desc("use instrumentation with slow path for all accesses"), cl::Hidden, cl::init(false))
static const uint64_t kNetBSD_ShadowOffset32
static const uint64_t kFreeBSDAArch64_ShadowOffset64
static const uint64_t kSmallX86_64ShadowOffsetBase
static cl::opt< bool > ClInitializers("asan-initialization-order", cl::desc("Handle C++ initializer order"), cl::Hidden, cl::init(true))
static const uint64_t kNetBSD_ShadowOffset64
const char kAsanPtrSub[]
static cl::opt< unsigned > ClRealignStack("asan-realign-stack", cl::desc("Realign stack to the value of this flag (power of two)"), cl::Hidden, cl::init(32))
static const uint64_t kWindowsShadowOffset32
static cl::opt< bool > ClInstrumentReads("asan-instrument-reads", cl::desc("instrument read instructions"), cl::Hidden, cl::init(true))
const char kAsanAllocaPoison[]
constexpr size_t kCompileKernelShift
static cl::opt< bool > ClWithIfunc("asan-with-ifunc", cl::desc("Access dynamic shadow through an ifunc global on " "platforms that support this"), cl::Hidden, cl::init(true))
static cl::opt< bool > ClKasanMemIntrinCallbackPrefix("asan-kernel-mem-intrinsic-prefix", cl::desc("Use prefix for memory intrinsics in KASAN mode"), cl::Hidden, cl::init(false))
const char kAsanVersionCheckNamePrefix[]
const char kAMDGPUAddressPrivateName[]
static const uint64_t kNetBSDKasan_ShadowOffset64
static void instrumentMaskedLoadOrStore(AddressSanitizer *Pass, const DataLayout &DL, Type *IntptrTy, Value *Mask, Instruction *I, Value *Addr, MaybeAlign Alignment, unsigned Granularity, Type *OpType, bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp)
const char kAsanRegisterElfGlobalsName[]
static cl::opt< uint64_t > ClMappingOffset("asan-mapping-offset", cl::desc("offset of asan shadow mapping [EXPERIMENTAL]"), cl::Hidden, cl::init(0))
const char kAsanReportErrorTemplate[]
static cl::opt< bool > ClWithComdat("asan-with-comdat", cl::desc("Place ASan constructors in comdat sections"), cl::Hidden, cl::init(true))
static cl::opt< bool > ClSkipPromotableAllocas("asan-skip-promotable-allocas", cl::desc("Do not instrument promotable allocas"), cl::Hidden, cl::init(true))
static cl::opt< int > ClMaxInsnsToInstrumentPerBB("asan-max-ins-per-bb", cl::init(10000), cl::desc("maximal number of instructions to instrument in any given BB"), cl::Hidden)
static const uintptr_t kRetiredStackFrameMagic
const char kAsanPoisonGlobalsName[]
const char kAsanHandleNoReturnName[]
static const size_t kMinStackMallocSize
static cl::opt< int > ClDebug("asan-debug", cl::desc("debug"), cl::Hidden, cl::init(0))
const char kAsanAllocasUnpoison[]
static const uint64_t kAArch64_ShadowOffset64
static cl::opt< bool > ClInvalidPointerPairs("asan-detect-invalid-pointer-pair", cl::desc("Instrument <, <=, >, >=, - with pointer operands"), cl::Hidden, cl::init(false))
This file contains the simple types necessary to represent the attributes associated with functions a...
static const Function * getParent(const Value *V)
SmallVector< MachineOperand, 4 > Cond
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
#define clEnumValN(ENUMVAL, FLAGNAME, DESC)
Definition: CommandLine.h:678
This file contains the declarations for the subclasses of Constant, which represent the different fla...
Returns the sub type a function will return at a given Idx Should correspond to the result type of an ExtractValue instruction executed with just that one unsigned Idx
#define LLVM_DEBUG(X)
Definition: Debug.h:101
This file defines the DenseMap class.
This file builds on the ADT/GraphTraits.h file to build generic depth first graph iterator.
uint64_t Addr
std::string Name
uint64_t Size
static bool runOnFunction(Function &F, bool PostInlining)
This is the interface for a simple mod/ref and alias analysis over globals.
IRTranslator LLVM IR MI
static LVOptions Options
Definition: LVOptions.cpp:25
static M68kRelType getType(unsigned Kind, MCSymbolRefExpr::VariantKind &Modifier, bool &IsPCRel)
#define F(x, y, z)
Definition: MD5.cpp:55
#define I(x, y, z)
Definition: MD5.cpp:58
#define G(x, y, z)
Definition: MD5.cpp:56
This file contains the declarations for metadata subclasses.
Module.h This file contains the declarations for the Module class.
IntegerType * Int32Ty
FunctionAnalysisManager FAM
ModuleAnalysisManager MAM
@ SI
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
This file defines the SmallPtrSet class.
This file defines the SmallVector class.
This file defines the 'Statistic' class, which is designed to be an easy way to expose various metric...
#define STATISTIC(VARNAME, DESC)
Definition: Statistic.h:167
This file contains some functions that are useful when dealing with strings.
This defines the Use class.
AddressSanitizerPass(const AddressSanitizerOptions &Options, bool UseGlobalGC=true, bool UseOdrIndicator=true, AsanDtorKind DestructorKind=AsanDtorKind::Global, AsanCtorKind ConstructorKind=AsanCtorKind::Global)
PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM)
void printPipeline(raw_ostream &OS, function_ref< StringRef(StringRef)> MapClassName2PassName)
an instruction to allocate memory on the stack
Definition: Instructions.h:58
bool isSwiftError() const
Return true if this alloca is used as a swifterror argument to a call.
Definition: Instructions.h:150
bool isStaticAlloca() const
Return true if this alloca is in the entry block of the function and is a constant size.
Align getAlign() const
Return the alignment of the memory that is being allocated by the instruction.
Definition: Instructions.h:125
PointerType * getType() const
Overload to return most specific pointer type.
Definition: Instructions.h:100
Type * getAllocatedType() const
Return the type that is being allocated by the instruction.
Definition: Instructions.h:118
bool isUsedWithInAlloca() const
Return true if this alloca is used as an inalloca argument to a call.
Definition: Instructions.h:140
bool isArrayAllocation() const
Return true if there is an allocation size parameter to the allocation instruction that is not 1.
void setAlignment(Align Align)
Definition: Instructions.h:129
const Value * getArraySize() const
Get the number of elements allocated.
Definition: Instructions.h:96
A container for analyses that lazily runs them and caches their results.
Definition: PassManager.h:620
PassT::Result & getResult(IRUnitT &IR, ExtraArgTs... ExtraArgs)
Get the result of an analysis pass for a given IR unit.
Definition: PassManager.h:774
This class represents an incoming formal argument to a Function.
Definition: Argument.h:28
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory),...
Definition: ArrayRef.h:41
size_t size() const
size - Get the array size.
Definition: ArrayRef.h:163
static ArrayType * get(Type *ElementType, uint64_t NumElements)
This static method is the primary way to construct an ArrayType.
Definition: Type.cpp:652
An instruction that atomically checks whether a specified value is in a memory location,...
Definition: Instructions.h:513
an instruction that atomically reads a memory location, combines it with another value,...
Definition: Instructions.h:718
AttributeList addParamAttribute(LLVMContext &C, unsigned ArgNo, Attribute::AttrKind Kind) const
Add an argument attribute to the list.
Definition: Attributes.h:570
LLVM Basic Block Representation.
Definition: BasicBlock.h:56
iterator begin()
Instruction iterator methods.
Definition: BasicBlock.h:314
const_iterator getFirstInsertionPt() const
Returns an iterator to the first instruction in this block that is suitable for inserting a non-PHI i...
Definition: BasicBlock.cpp:245
static BasicBlock * Create(LLVMContext &Context, const Twine &Name="", Function *Parent=nullptr, BasicBlock *InsertBefore=nullptr)
Creates a new BasicBlock.
Definition: BasicBlock.h:105
const Function * getParent() const
Return the enclosing method, or null if none.
Definition: BasicBlock.h:112
const CallInst * getTerminatingMustTailCall() const
Returns the call instruction marked 'musttail' prior to the terminating return instruction of this ba...
Definition: BasicBlock.cpp:150
Conditional or Unconditional Branch instruction.
static BranchInst * Create(BasicBlock *IfTrue, Instruction *InsertBefore=nullptr)
Base class for all callable instructions (InvokeInst and CallInst) Holds everything related to callin...
Definition: InstrTypes.h:1184
bool isInlineAsm() const
Check if this call is an inline asm statement.
Definition: InstrTypes.h:1474
Value * getArgOperand(unsigned i) const
Definition: InstrTypes.h:1351
iterator_range< User::op_iterator > args()
Iteration adapter for range-for loops.
Definition: InstrTypes.h:1342
bool doesNotReturn() const
Determine if the call cannot return.
Definition: InstrTypes.h:1901
unsigned arg_size() const
Definition: InstrTypes.h:1349
This class represents a function call, abstracting a target machine's calling convention.
static CallInst * Create(FunctionType *Ty, Value *F, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
@ Largest
The linker will choose the largest COMDAT.
Definition: Comdat.h:38
@ SameSize
The data referenced by the COMDAT must be the same size.
Definition: Comdat.h:40
@ Any
The linker may choose any COMDAT.
Definition: Comdat.h:36
@ NoDeduplicate
No deduplication is performed.
Definition: Comdat.h:39
@ ExactMatch
The data referenced by the COMDAT must be the same.
Definition: Comdat.h:37
ConstantArray - Constant Array Declarations.
Definition: Constants.h:409
static Constant * get(ArrayType *T, ArrayRef< Constant * > V)
Definition: Constants.cpp:1249
static Constant * getIntToPtr(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:2215
static Constant * getPointerCast(Constant *C, Type *Ty)
Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant expression.
Definition: Constants.cpp:2041
static Constant * getGetElementPtr(Type *Ty, Constant *C, ArrayRef< Constant * > IdxList, bool InBounds=false, std::optional< unsigned > InRangeIndex=std::nullopt, Type *OnlyIfReducedTy=nullptr)
Getelementptr form.
Definition: Constants.h:1245
This is the shared class of boolean and integer constants.
Definition: Constants.h:78
IntegerType * getType() const
getType - Specialize the getType() method to always return an IntegerType, which reduces the amount o...
Definition: Constants.h:172
static bool isValueValidForType(Type *Ty, uint64_t V)
This static method returns true if the type Ty is big enough to represent the value V.
Definition: Constants.cpp:1520
static Constant * get(Type *Ty, uint64_t V, bool IsSigned=false)
If Ty is a vector type, return a Constant with a splat of the given value.
Definition: Constants.cpp:887
uint64_t getZExtValue() const
Return the constant as a 64-bit unsigned integer value after it has been zero extended as appropriate...
Definition: Constants.h:141
static Constant * get(StructType *T, ArrayRef< Constant * > V)
Definition: Constants.cpp:1314
This is an important base class in LLVM.
Definition: Constant.h:41
static Constant * getNullValue(Type *Ty)
Constructor to create a '0' constant of arbitrary type.
Definition: Constants.cpp:356
Constant * getAggregateElement(unsigned Elt) const
For aggregates (struct/array/vector) return the constant that corresponds to the specified element if...
Definition: Constants.cpp:418
Debug location.
A parsed version of the target data layout string in and methods for querying it.
Definition: DataLayout.h:114
TypeSize getTypeAllocSize(Type *Ty) const
Returns the offset in bytes between successive objects of the specified type, including alignment pad...
Definition: DataLayout.h:507
A debug info location.
Definition: DebugLoc.h:33
DILocation * get() const
Get the underlying DILocation.
Definition: DebugLoc.cpp:20
A handy container for a FunctionType+Callee-pointer pair, which can be passed around as a single enti...
Definition: DerivedTypes.h:165
static FunctionType * get(Type *Result, ArrayRef< Type * > Params, bool isVarArg)
This static method is the primary way of constructing a FunctionType.
const BasicBlock & front() const
Definition: Function.h:758
static Function * createWithDefaultAttr(FunctionType *Ty, LinkageTypes Linkage, unsigned AddrSpace, const Twine &N="", Module *M=nullptr)
Creates a function with some attributes recorded in llvm.module.flags applied.
Definition: Function.cpp:332
const Constant * getAliasee() const
Definition: GlobalAlias.h:84
static GlobalAlias * create(Type *Ty, unsigned AddressSpace, LinkageTypes Linkage, const Twine &Name, Constant *Aliasee, Module *Parent)
If a parent module is specified, the alias is automatically inserted into the end of the specified mo...
Definition: Globals.cpp:520
void setAlignment(Align Align)
Sets the alignment attribute of the GlobalObject.
Definition: Globals.cpp:130
void copyMetadata(const GlobalObject *Src, unsigned Offset)
Copy metadata from Src, adjusting offsets by Offset.
Definition: Metadata.cpp:1550
void setComdat(Comdat *C)
Definition: Globals.cpp:198
void setSection(StringRef S)
Change the section for this global.
Definition: Globals.cpp:252
VisibilityTypes getVisibility() const
Definition: GlobalValue.h:244
void setUnnamedAddr(UnnamedAddr Val)
Definition: GlobalValue.h:227
bool hasLocalLinkage() const
Definition: GlobalValue.h:523
static StringRef dropLLVMManglingEscape(StringRef Name)
If the given string begins with the GlobalValue name mangling escape character '\1',...
Definition: GlobalValue.h:562
ThreadLocalMode getThreadLocalMode() const
Definition: GlobalValue.h:267
Module * getParent()
Get the module that this global value is contained inside of...
Definition: GlobalValue.h:652
@ HiddenVisibility
The GV is hidden.
Definition: GlobalValue.h:64
void setVisibility(VisibilityTypes V)
Definition: GlobalValue.h:250
LinkageTypes
An enumeration for the kinds of linkage for global values.
Definition: GlobalValue.h:47
@ PrivateLinkage
Like Internal, but omit from symbol table.
Definition: GlobalValue.h:56
@ CommonLinkage
Tentative definitions.
Definition: GlobalValue.h:58
@ InternalLinkage
Rename collisions when linking (static functions).
Definition: GlobalValue.h:55
@ AvailableExternallyLinkage
Available for inspection, not emission.
Definition: GlobalValue.h:49
@ ExternalWeakLinkage
ExternalWeak linkage description.
Definition: GlobalValue.h:57
DLLStorageClassTypes getDLLStorageClass() const
Definition: GlobalValue.h:271
const Constant * getInitializer() const
getInitializer - Return the initializer for this global variable.
void copyAttributesFrom(const GlobalVariable *Src)
copyAttributesFrom - copy all additional attributes (those not needed to create a GlobalVariable) fro...
Definition: Globals.cpp:495
Analysis pass providing a never-invalidated alias analysis result.
This instruction compares its operands according to the predicate given to the constructor.
AllocaInst * CreateAlloca(Type *Ty, unsigned AddrSpace, Value *ArraySize=nullptr, const Twine &Name="")
Definition: IRBuilder.h:1688
IntegerType * getInt1Ty()
Fetch the type representing a single bit.
Definition: IRBuilder.h:497
Value * CreateExtractElement(Value *Vec, Value *Idx, const Twine &Name="")
Definition: IRBuilder.h:2341
Value * CreatePointerCast(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:2054
Value * CreateICmpSGE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:2150
Value * CreateSelect(Value *C, Value *True, Value *False, const Twine &Name="", Instruction *MDFrom=nullptr)
Definition: IRBuilder.cpp:1126
Value * CreateIntToPtr(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:2003
Value * CreateLShr(Value *LHS, Value *RHS, const Twine &Name="", bool isExact=false)
Definition: IRBuilder.h:1352
IntegerType * getInt32Ty()
Fetch the type representing a 32-bit integer.
Definition: IRBuilder.h:512
BasicBlock * GetInsertBlock() const
Definition: IRBuilder.h:174
IntegerType * getInt64Ty()
Fetch the type representing a 64-bit integer.
Definition: IRBuilder.h:517
Value * CreateICmpNE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:2126
ConstantInt * getInt32(uint32_t C)
Get a constant 32-bit value.
Definition: IRBuilder.h:472
PHINode * CreatePHI(Type *Ty, unsigned NumReservedValues, const Twine &Name="")
Definition: IRBuilder.h:2278
Value * CreateNot(Value *V, const Twine &Name="")
Definition: IRBuilder.h:1664
Value * CreateICmpEQ(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:2122
Value * CreateSub(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1259
ConstantInt * getIntN(unsigned N, uint64_t C)
Get a constant N-bit value, zero extended or truncated from a 64-bit value.
Definition: IRBuilder.h:483
LoadInst * CreateLoad(Type *Ty, Value *Ptr, const char *Name)
Provided to resolve 'CreateLoad(Ty, Ptr, "...")' correctly, instead of converting the string to 'bool...
Definition: IRBuilder.h:1705
PointerType * getInt8PtrTy(unsigned AddrSpace=0)
Fetch the type representing a pointer to an 8-bit integer value.
Definition: IRBuilder.h:560
Value * CreateAnd(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1390
StoreInst * CreateStore(Value *Val, Value *Ptr, bool isVolatile=false)
Definition: IRBuilder.h:1718
Value * CreateAdd(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1242
Value * CreatePtrToInt(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:1998
Value * CreateIsNotNull(Value *Arg, const Twine &Name="")
Return a boolean value testing if Arg != 0.
Definition: IRBuilder.h:2430
Value * CreateOr(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1412
Value * CreateIntCast(Value *V, Type *DestTy, bool isSigned, const Twine &Name="")
Definition: IRBuilder.h:2077
void SetInsertPoint(BasicBlock *TheBB)
This specifies that created instructions should be appended to the end of the specified block.
Definition: IRBuilder.h:180
Type * getVoidTy()
Fetch the type representing void.
Definition: IRBuilder.h:550
StoreInst * CreateAlignedStore(Value *Val, Value *Ptr, MaybeAlign Align, bool isVolatile=false)
Definition: IRBuilder.h:1741
CallInst * CreateCall(FunctionType *FTy, Value *Callee, ArrayRef< Value * > Args=std::nullopt, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:2293
Value * CreateGEP(Type *Ty, Value *Ptr, ArrayRef< Value * > IdxList, const Twine &Name="", bool IsInBounds=false)
Definition: IRBuilder.h:1781
IntegerType * getInt8Ty()
Fetch the type representing an 8-bit integer.
Definition: IRBuilder.h:502
CallInst * CreateMemCpy(Value *Dst, MaybeAlign DstAlign, Value *Src, MaybeAlign SrcAlign, uint64_t Size, bool isVolatile=false, MDNode *TBAATag=nullptr, MDNode *TBAAStructTag=nullptr, MDNode *ScopeTag=nullptr, MDNode *NoAliasTag=nullptr)
Create and insert a memcpy between the specified pointers.
Definition: IRBuilder.h:628
Value * CreateMul(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1276
This provides a uniform API for creating instructions and inserting them into a basic block: either a...
Definition: IRBuilder.h:2550
static InlineAsm * get(FunctionType *Ty, StringRef AsmString, StringRef Constraints, bool hasSideEffects, bool isAlignStack=false, AsmDialect asmDialect=AD_ATT, bool canThrow=false)
InlineAsm::get - Return the specified uniqued inline asm string.
Definition: InlineAsm.cpp:43
An analysis over an "outer" IR unit that provides access to an analysis manager over an "inner" IR un...
Definition: PassManager.h:933
Base class for instruction visitors.
Definition: InstVisitor.h:78
RetTy visitCallBase(CallBase &I)
Definition: InstVisitor.h:267
RetTy visitCleanupReturnInst(CleanupReturnInst &I)
Definition: InstVisitor.h:244
RetTy visitIntrinsicInst(IntrinsicInst &I)
Definition: InstVisitor.h:219
void visit(Iterator Start, Iterator End)
Definition: InstVisitor.h:87
RetTy visitReturnInst(ReturnInst &I)
Definition: InstVisitor.h:226
RetTy visitAllocaInst(AllocaInst &I)
Definition: InstVisitor.h:168
RetTy visitResumeInst(ResumeInst &I)
Definition: InstVisitor.h:238
bool isLifetimeStartOrEnd() const LLVM_READONLY
Return true if the instruction is a llvm.lifetime.start or llvm.lifetime.end marker.
const DebugLoc & getDebugLoc() const
Return the debug location for this node as a DebugLoc.
Definition: Instruction.h:358
const Module * getModule() const
Return the module owning the function this instruction belongs to or nullptr it the function does not...
Definition: Instruction.cpp:70
bool hasMetadata() const
Return true if this instruction has any metadata attached to it.
Definition: Instruction.h:257
const BasicBlock * getParent() const
Definition: Instruction.h:90
BasicBlock * getSuccessor(unsigned Idx) const LLVM_READONLY
Return the specified successor. This instruction must be a terminator.
const Instruction * getNextNonDebugInstruction(bool SkipPseudoOp=false) const
Return a pointer to the next non-debug instruction in the same basic block as 'this',...
SymbolTableList< Instruction >::iterator eraseFromParent()
This method unlinks 'this' from the containing basic block and deletes it.
Definition: Instruction.cpp:82
void setDebugLoc(DebugLoc Loc)
Set the debug location information for this instruction.
Definition: Instruction.h:355
void moveBefore(Instruction *MovePos)
Unlink this instruction from its current basic block and insert it into the basic block that MovePos ...
static IntegerType * get(LLVMContext &C, unsigned NumBits)
This static method is the primary way of constructing an IntegerType.
Definition: Type.cpp:325
A wrapper class for inspecting calls to intrinsic functions.
Definition: IntrinsicInst.h:47
Intrinsic::ID getIntrinsicID() const
Return the intrinsic ID of this intrinsic.
Definition: IntrinsicInst.h:54
This is an important class for using LLVM in a threaded context.
Definition: LLVMContext.h:67
An instruction for reading from memory.
Definition: Instructions.h:177
static Error ParseSectionSpecifier(StringRef Spec, StringRef &Segment, StringRef &Section, unsigned &TAA, bool &TAAParsed, unsigned &StubSize)
Parse the section specifier indicated by "Spec".
MDNode * createBranchWeights(uint32_t TrueWeight, uint32_t FalseWeight)
Return metadata containing two branch weights.
Definition: MDBuilder.cpp:37
Metadata node.
Definition: Metadata.h:943
static MDTuple * get(LLVMContext &Context, ArrayRef< Metadata * > MDs)
Definition: Metadata.h:1399
This is the common base class for memset/memcpy/memmove.
Root of the metadata hierarchy.
Definition: Metadata.h:61
A Module instance is used to store all the information related to an LLVM module.
Definition: Module.h:65
const DataLayout & getDataLayout() const
Get the data layout for the module's target platform.
Definition: Module.cpp:398
Evaluate the size and offset of an object pointed to by a Value* statically.
static bool bothKnown(const SizeOffsetType &SizeOffset)
SizeOffsetType compute(Value *V)
Pass interface - Implemented by all 'passes'.
Definition: Pass.h:91
static PointerType * get(Type *ElementType, unsigned AddressSpace)
This constructs a pointer to an object of the specified type in a numbered address space.
A set of analyses that are preserved following a run of a transformation pass.
Definition: PassManager.h:152
static PreservedAnalyses none()
Convenience factory function for the empty preserved set.
Definition: PassManager.h:155
static PreservedAnalyses all()
Construct a special preserved set that preserves all passes.
Definition: PassManager.h:158
void abandon()
Mark an analysis as abandoned.
Definition: PassManager.h:206
Resume the propagation of an exception.
Return a value (possibly void), from a function.
static ReturnInst * Create(LLVMContext &C, Value *retVal=nullptr, Instruction *InsertBefore=nullptr)
size_type count(ConstPtrType Ptr) const
count - Return 1 if the specified pointer is in the set, 0 otherwise.
Definition: SmallPtrSet.h:383
std::pair< iterator, bool > insert(PtrType Ptr)
Inserts Ptr if and only if there is no element in the container equal to Ptr.
Definition: SmallPtrSet.h:365
SmallPtrSet - This class implements a set which is optimized for holding SmallSize or less elements.
Definition: SmallPtrSet.h:450
bool empty() const
Definition: SmallVector.h:94
size_t size() const
Definition: SmallVector.h:91
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: SmallVector.h:577
reference emplace_back(ArgTypes &&... Args)
Definition: SmallVector.h:941
void reserve(size_type N)
Definition: SmallVector.h:667
void resize(size_type N)
Definition: SmallVector.h:642
void push_back(const T &Elt)
Definition: SmallVector.h:416
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1200
This pass performs the global (interprocedural) stack safety analysis (new pass manager).
bool stackAccessIsSafe(const Instruction &I) const
bool isSafe(const AllocaInst &AI) const
An instruction for storing to memory.
Definition: Instructions.h:301
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:50
constexpr bool empty() const
empty - Check if the string is empty.
Definition: StringRef.h:134
bool startswith(StringRef Prefix) const
Definition: StringRef.h:261
const char * data() const
data - Get a pointer to the start of the string (which may not be null terminated).
Definition: StringRef.h:131
Class to represent struct types.
Definition: DerivedTypes.h:213
static StructType * get(LLVMContext &Context, ArrayRef< Type * > Elements, bool isPacked=false)
This static method is the primary way to create a literal StructType.
Definition: Type.cpp:420
Analysis pass providing the TargetLibraryInfo.
Provides information about what library functions are available for the current target.
AttributeList getAttrList(LLVMContext *C, ArrayRef< unsigned > ArgNos, bool Signed, bool Ret=false, AttributeList AL=AttributeList()) const
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:44
bool isAndroidVersionLT(unsigned Major) const
Definition: Triple.h:726
bool isThumb() const
Tests whether the target is Thumb (little and big endian).
Definition: Triple.h:774
bool isDriverKit() const
Is this an Apple DriverKit triple.
Definition: Triple.h:513
bool isOSNetBSD() const
Definition: Triple.h:536
bool isAndroid() const
Tests whether the target is Android.
Definition: Triple.h:724
bool isMIPS64() const
Tests whether the target is MIPS 64-bit (little and big endian).
Definition: Triple.h:860
@ loongarch64
Definition: Triple.h:62
ArchType getArch() const
Get the parsed architecture type of this triple.
Definition: Triple.h:355
EnvironmentType getEnvironment() const
Get the parsed environment type of this triple.
Definition: Triple.h:372
bool isMIPS32() const
Tests whether the target is MIPS 32-bit (little and big endian).
Definition: Triple.h:855
bool isOSWindows() const
Tests whether the OS is Windows.
Definition: Triple.h:583
@ DXContainer
Definition: Triple.h:283
@ UnknownObjectFormat
Definition: Triple.h:280
bool isARM() const
Tests whether the target is ARM (little and big endian).
Definition: Triple.h:779
bool isOSLinux() const
Tests whether the OS is Linux.
Definition: Triple.h:637
bool isAMDGPU() const
Definition: Triple.h:769
bool isMacOSX() const
Is this a Mac OS X triple.
Definition: Triple.h:485
bool isOSFreeBSD() const
Definition: Triple.h:544
bool isOSEmscripten() const
Tests whether the OS is Emscripten.
Definition: Triple.h:657
bool isWatchOS() const
Is this an Apple watchOS triple.
Definition: Triple.h:504
bool isiOS() const
Is this an iOS triple.
Definition: Triple.h:494
bool isPS() const
Tests whether the target is the PS4 or PS5 platform.
Definition: Triple.h:721
bool isOSFuchsia() const
Definition: Triple.h:548
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
The instances of the Type class are immutable: once they are created, they are never changed.
Definition: Type.h:45
PointerType * getPointerTo(unsigned AddrSpace=0) const
Return a pointer to the current type.
bool isPointerTy() const
True if this is an instance of PointerType.
Definition: Type.h:249
unsigned getPointerAddressSpace() const
Get the address space of this pointer or pointer vector type.
static IntegerType * getIntNTy(LLVMContext &C, unsigned N)
static Type * getVoidTy(LLVMContext &C)
bool isSized(SmallPtrSetImpl< Type * > *Visited=nullptr) const
Return true if it makes sense to take the size of this type.
Definition: Type.h:295
static PointerType * getInt8PtrTy(LLVMContext &C, unsigned AS=0)
static IntegerType * getInt32Ty(LLVMContext &C)
This function has undefined behavior.
A Use represents the edge between a Value definition and its users.
Definition: Use.h:43
op_range operands()
Definition: User.h:242
Value * getOperand(unsigned i) const
Definition: User.h:169
static ValueAsMetadata * get(Value *V)
Definition: Metadata.cpp:392
LLVM Value Representation.
Definition: Value.h:74
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:255
void replaceAllUsesWith(Value *V)
Change all uses of this to point to a new Value.
Definition: Value.cpp:532
StringRef getName() const
Return a constant reference to the value's name.
Definition: Value.cpp:308
void takeName(Value *V)
Transfer the name from V to this value.
Definition: Value.cpp:381
An efficient, type-erasing, non-owning reference to a callable.
NodeTy * getNextNode()
Get the next node, or nullptr for the list tail.
Definition: ilist_node.h:289
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:52
This file contains the declaration of the Comdat class, which represents a single COMDAT in LLVM.
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
constexpr std::underlying_type_t< E > Mask()
Get a bitmask with 1s in all places up to the high-order bit of E's largest value.
Definition: BitmaskEnum.h:80
@ C
The default llvm calling convention, compatible with C.
Definition: CallingConv.h:34
const uint64_t Version
Definition: InstrProf.h:1058
Function * getDeclaration(Module *M, ID id, ArrayRef< Type * > Tys=std::nullopt)
Create or insert an LLVM Function declaration for an intrinsic, and return it.
Definition: Function.cpp:1502
@ S_CSTRING_LITERALS
S_CSTRING_LITERALS - Section with literal C strings.
Definition: MachO.h:131
ValuesClass values(OptsTy... Options)
Helper to build a ValuesClass by forwarding a variable number of arguments as an initializer list to ...
Definition: CommandLine.h:703
initializer< Ty > init(const Ty &Val)
Definition: CommandLine.h:445
uint64_t getAllocaSizeInBytes(const AllocaInst &AI)
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
void ReplaceInstWithInst(BasicBlock *BB, BasicBlock::iterator &BI, Instruction *I)
Replace the instruction specified by BI with the instruction specified by I.
@ Offset
Definition: DWP.cpp:406
bool all_of(R &&range, UnaryPredicate P)
Provide wrappers to std::all_of which take ranges instead of having to pass begin/end explicitly.
Definition: STLExtras.h:1735
SmallVector< uint8_t, 64 > GetShadowBytesAfterScope(const SmallVectorImpl< ASanStackVariableDescription > &Vars, const ASanStackFrameLayout &Layout)
std::string demangle(const std::string &MangledName)
Attempt to demangle a string using different demangling schemes.
Definition: Demangle.cpp:29
std::pair< APInt, APInt > SizeOffsetType
AllocaInst * findAllocaForValue(Value *V, bool OffsetZero=false)
Returns unique alloca where the value comes from, or nullptr.
@ Done
Definition: Threading.h:61
Function * createSanitizerCtor(Module &M, StringRef CtorName)
Creates sanitizer constructor function.
AsanDetectStackUseAfterReturnMode
Mode of ASan detect stack use after return.
@ Always
Always detect stack use after return.
@ Never
Never detect stack use after return.
@ Runtime
Detect stack use after return if not disabled runtime with (ASAN_OPTIONS=detect_stack_use_after_retur...
GlobalVariable * createPrivateGlobalForString(Module &M, StringRef Str, bool AllowMerging, const char *NamePrefix="")
const Value * getUnderlyingObject(const Value *V, unsigned MaxLookup=6)
This method strips off any GEP address adjustments and pointer casts from the specified value,...
void SplitBlockAndInsertIfThenElse(Value *Cond, Instruction *SplitBefore, Instruction **ThenTerm, Instruction **ElseTerm, MDNode *BranchWeights=nullptr, DomTreeUpdater *DTU=nullptr)
SplitBlockAndInsertIfThenElse is similar to SplitBlockAndInsertIfThen, but also creates the ElseBlock...
bool isAllocaPromotable(const AllocaInst *AI)
Return true if this alloca is legal for promotion.
SmallString< 64 > ComputeASanStackFrameDescription(const SmallVectorImpl< ASanStackVariableDescription > &Vars)
SmallVector< uint8_t, 64 > GetShadowBytes(const SmallVectorImpl< ASanStackVariableDescription > &Vars, const ASanStackFrameLayout &Layout)
int countr_zero(T Val)
Count number of 0's from the least significant bit to the most stopping at the first 1.
Definition: bit.h:179
FunctionCallee declareSanitizerInitFunction(Module &M, StringRef InitName, ArrayRef< Type * > InitArgTypes, bool Weak=false)
std::string getUniqueModuleId(Module *M)
Produce a unique identifier for this module by taking the MD5 sum of the names of the module's strong...
constexpr bool isPowerOf2_32(uint32_t Value)
Return true if the argument is a power of two > 0.
Definition: MathExtras.h:288
std::pair< Function *, FunctionCallee > createSanitizerCtorAndInitFunctions(Module &M, StringRef CtorName, StringRef InitName, ArrayRef< Type * > InitArgTypes, ArrayRef< Value * > InitArgs, StringRef VersionCheckName=StringRef(), bool Weak=false)
Creates sanitizer constructor function, and calls sanitizer's init function from it.
decltype(auto) get(const PointerIntPair< PointerTy, IntBits, IntType, PtrTraits, Info > &Pair)
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:163
void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:145
AsanDtorKind
Types of ASan module destructors supported.
@ None
Do not emit any destructors for ASan.
ASanStackFrameLayout ComputeASanStackFrameLayout(SmallVectorImpl< ASanStackVariableDescription > &Vars, uint64_t Granularity, uint64_t MinHeaderSize)
void cantFail(Error Err, const char *Msg=nullptr)
Report a fatal error if Err is a failure value.
Definition: Error.h:745
void appendToCompilerUsed(Module &M, ArrayRef< GlobalValue * > Values)
Adds global values to the llvm.compiler.used list.
static const int kAsanStackUseAfterReturnMagic
@ Dynamic
Denotes mode unknown at compile time.
void appendToGlobalCtors(Module &M, Function *F, int Priority, Constant *Data=nullptr)
Append F to the list of global ctors of module M with the given Priority.
Definition: ModuleUtils.cpp:69
Align assumeAligned(uint64_t Value)
Treats the value 0 as a 1, so Align is always at least 1.
Definition: Alignment.h:111
iterator_range< df_iterator< T > > depth_first(const T &G)
Instruction * SplitBlockAndInsertIfThen(Value *Cond, Instruction *SplitBefore, bool Unreachable, MDNode *BranchWeights, DominatorTree *DT, LoopInfo *LI=nullptr, BasicBlock *ThenBlock=nullptr)
Split the containing block at the specified instruction - everything before SplitBefore stays in the ...
AsanCtorKind
Types of ASan module constructors supported.
void maybeMarkSanitizerLibraryCallNoBuiltin(CallInst *CI, const TargetLibraryInfo *TLI)
Given a CallInst, check if it calls a string function known to CodeGen, and mark it with NoBuiltin if...
Definition: Local.cpp:3394
void appendToUsed(Module &M, ArrayRef< GlobalValue * > Values)
Adds global values to the llvm.used list.
void appendToGlobalDtors(Module &M, Function *F, int Priority, Constant *Data=nullptr)
Same as appendToGlobalCtors(), but for global dtors.
Definition: ModuleUtils.cpp:73
void getAddressSanitizerParams(const Triple &TargetTriple, int LongSize, bool IsKasan, uint64_t *ShadowBase, int *MappingScale, bool *OrShadowOffset)
bool replaceDbgDeclare(Value *Address, Value *NewAddress, DIBuilder &Builder, uint8_t DIExprFlags, int Offset)
Replaces llvm.dbg.declare instruction when the address it describes is replaced with a new value.
Definition: Local.cpp:1767
#define N
#define OP(n)
Definition: regex2.h:73
ASanAccessInfo(int32_t Packed)
AsanDetectStackUseAfterReturnMode UseAfterReturn
This struct is a compact representation of a valid (non-zero power of two) alignment.
Definition: Alignment.h:39
uint64_t value() const
This is a hole in the type system and should not be abused.
Definition: Alignment.h:85
This struct is a compact representation of a valid (power of two) or undefined (0) alignment.
Definition: Alignment.h:117
Various options to control the behavior of getObjectSize.
bool RoundToAlign
Whether to round the result up to the alignment of allocas, byval arguments, and global variables.
A CRTP mix-in to automatically provide informational APIs needed for passes.
Definition: PassManager.h:371