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/Twine.h"
35#include "llvm/IR/Argument.h"
36#include "llvm/IR/Attributes.h"
37#include "llvm/IR/BasicBlock.h"
38#include "llvm/IR/Comdat.h"
39#include "llvm/IR/Constant.h"
40#include "llvm/IR/Constants.h"
41#include "llvm/IR/DIBuilder.h"
42#include "llvm/IR/DataLayout.h"
44#include "llvm/IR/DebugLoc.h"
46#include "llvm/IR/Function.h"
47#include "llvm/IR/GlobalAlias.h"
48#include "llvm/IR/GlobalValue.h"
50#include "llvm/IR/IRBuilder.h"
51#include "llvm/IR/InlineAsm.h"
52#include "llvm/IR/InstVisitor.h"
53#include "llvm/IR/InstrTypes.h"
54#include "llvm/IR/Instruction.h"
57#include "llvm/IR/Intrinsics.h"
58#include "llvm/IR/LLVMContext.h"
59#include "llvm/IR/MDBuilder.h"
60#include "llvm/IR/Metadata.h"
61#include "llvm/IR/Module.h"
62#include "llvm/IR/Type.h"
63#include "llvm/IR/Use.h"
64#include "llvm/IR/Value.h"
68#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 TypeSize getAllocaSizeInBytes(const AllocaInst &AI) const {
671 return *AI.getAllocationSize(AI.getModule()->getDataLayout());
672 }
673
674 /// Check if we want (and can) handle this alloca.
675 bool isInterestingAlloca(const AllocaInst &AI);
676
677 bool ignoreAccess(Instruction *Inst, Value *Ptr);
678 void getInterestingMemoryOperands(
680
681 void instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
682 InterestingMemoryOperand &O, bool UseCalls,
683 const DataLayout &DL);
684 void instrumentPointerComparisonOrSubtraction(Instruction *I);
685 void instrumentAddress(Instruction *OrigIns, Instruction *InsertBefore,
686 Value *Addr, uint32_t TypeStoreSize, bool IsWrite,
687 Value *SizeArgument, bool UseCalls, uint32_t Exp);
688 Instruction *instrumentAMDGPUAddress(Instruction *OrigIns,
689 Instruction *InsertBefore, Value *Addr,
690 uint32_t TypeStoreSize, bool IsWrite,
691 Value *SizeArgument);
692 void instrumentUnusualSizeOrAlignment(Instruction *I,
693 Instruction *InsertBefore, Value *Addr,
694 TypeSize TypeStoreSize, bool IsWrite,
695 Value *SizeArgument, bool UseCalls,
696 uint32_t Exp);
697 Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
698 Value *ShadowValue, uint32_t TypeStoreSize);
699 Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
700 bool IsWrite, size_t AccessSizeIndex,
701 Value *SizeArgument, uint32_t Exp);
702 void instrumentMemIntrinsic(MemIntrinsic *MI);
703 Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
704 bool suppressInstrumentationSiteForDebug(int &Instrumented);
705 bool instrumentFunction(Function &F, const TargetLibraryInfo *TLI);
706 bool maybeInsertAsanInitAtFunctionEntry(Function &F);
707 bool maybeInsertDynamicShadowAtFunctionEntry(Function &F);
708 void markEscapedLocalAllocas(Function &F);
709
710private:
711 friend struct FunctionStackPoisoner;
712
713 void initializeCallbacks(Module &M, const TargetLibraryInfo *TLI);
714
715 bool LooksLikeCodeInBug11395(Instruction *I);
716 bool GlobalIsLinkerInitialized(GlobalVariable *G);
717 bool isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis, Value *Addr,
718 TypeSize TypeStoreSize) const;
719
720 /// Helper to cleanup per-function state.
721 struct FunctionStateRAII {
722 AddressSanitizer *Pass;
723
724 FunctionStateRAII(AddressSanitizer *Pass) : Pass(Pass) {
725 assert(Pass->ProcessedAllocas.empty() &&
726 "last pass forgot to clear cache");
727 assert(!Pass->LocalDynamicShadow);
728 }
729
730 ~FunctionStateRAII() {
731 Pass->LocalDynamicShadow = nullptr;
732 Pass->ProcessedAllocas.clear();
733 }
734 };
735
736 LLVMContext *C;
737 Triple TargetTriple;
738 int LongSize;
739 bool CompileKernel;
740 bool Recover;
741 bool UseAfterScope;
743 Type *IntptrTy;
744 Type *Int8PtrTy;
745 Type *Int32Ty;
746 ShadowMapping Mapping;
747 FunctionCallee AsanHandleNoReturnFunc;
748 FunctionCallee AsanPtrCmpFunction, AsanPtrSubFunction;
749 Constant *AsanShadowGlobal;
750
751 // These arrays is indexed by AccessIsWrite, Experiment and log2(AccessSize).
752 FunctionCallee AsanErrorCallback[2][2][kNumberOfAccessSizes];
753 FunctionCallee AsanMemoryAccessCallback[2][2][kNumberOfAccessSizes];
754
755 // These arrays is indexed by AccessIsWrite and Experiment.
756 FunctionCallee AsanErrorCallbackSized[2][2];
757 FunctionCallee AsanMemoryAccessCallbackSized[2][2];
758
759 FunctionCallee AsanMemmove, AsanMemcpy, AsanMemset;
760 Value *LocalDynamicShadow = nullptr;
761 const StackSafetyGlobalInfo *SSGI;
762 DenseMap<const AllocaInst *, bool> ProcessedAllocas;
763
764 FunctionCallee AMDGPUAddressShared;
765 FunctionCallee AMDGPUAddressPrivate;
766};
767
768class ModuleAddressSanitizer {
769public:
770 ModuleAddressSanitizer(Module &M, bool CompileKernel = false,
771 bool Recover = false, bool UseGlobalsGC = true,
772 bool UseOdrIndicator = true,
773 AsanDtorKind DestructorKind = AsanDtorKind::Global,
774 AsanCtorKind ConstructorKind = AsanCtorKind::Global)
775 : CompileKernel(ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan
776 : CompileKernel),
777 Recover(ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover),
778 UseGlobalsGC(UseGlobalsGC && ClUseGlobalsGC && !this->CompileKernel),
779 // Enable aliases as they should have no downside with ODR indicators.
780 UsePrivateAlias(ClUsePrivateAlias.getNumOccurrences() > 0
782 : UseOdrIndicator),
783 UseOdrIndicator(ClUseOdrIndicator.getNumOccurrences() > 0
785 : UseOdrIndicator),
786 // Not a typo: ClWithComdat is almost completely pointless without
787 // ClUseGlobalsGC (because then it only works on modules without
788 // globals, which are rare); it is a prerequisite for ClUseGlobalsGC;
789 // and both suffer from gold PR19002 for which UseGlobalsGC constructor
790 // argument is designed as workaround. Therefore, disable both
791 // ClWithComdat and ClUseGlobalsGC unless the frontend says it's ok to
792 // do globals-gc.
793 UseCtorComdat(UseGlobalsGC && ClWithComdat && !this->CompileKernel),
794 DestructorKind(DestructorKind),
795 ConstructorKind(ConstructorKind) {
796 C = &(M.getContext());
797 int LongSize = M.getDataLayout().getPointerSizeInBits();
798 IntptrTy = Type::getIntNTy(*C, LongSize);
799 TargetTriple = Triple(M.getTargetTriple());
800 Mapping = getShadowMapping(TargetTriple, LongSize, this->CompileKernel);
801
802 if (ClOverrideDestructorKind != AsanDtorKind::Invalid)
803 this->DestructorKind = ClOverrideDestructorKind;
804 assert(this->DestructorKind != AsanDtorKind::Invalid);
805 }
806
807 bool instrumentModule(Module &);
808
809private:
810 void initializeCallbacks(Module &M);
811
812 bool InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool *CtorComdat);
813 void InstrumentGlobalsCOFF(IRBuilder<> &IRB, Module &M,
814 ArrayRef<GlobalVariable *> ExtendedGlobals,
815 ArrayRef<Constant *> MetadataInitializers);
816 void InstrumentGlobalsELF(IRBuilder<> &IRB, Module &M,
817 ArrayRef<GlobalVariable *> ExtendedGlobals,
818 ArrayRef<Constant *> MetadataInitializers,
819 const std::string &UniqueModuleId);
820 void InstrumentGlobalsMachO(IRBuilder<> &IRB, Module &M,
821 ArrayRef<GlobalVariable *> ExtendedGlobals,
822 ArrayRef<Constant *> MetadataInitializers);
823 void
824 InstrumentGlobalsWithMetadataArray(IRBuilder<> &IRB, Module &M,
825 ArrayRef<GlobalVariable *> ExtendedGlobals,
826 ArrayRef<Constant *> MetadataInitializers);
827
828 GlobalVariable *CreateMetadataGlobal(Module &M, Constant *Initializer,
829 StringRef OriginalName);
830 void SetComdatForGlobalMetadata(GlobalVariable *G, GlobalVariable *Metadata,
831 StringRef InternalSuffix);
832 Instruction *CreateAsanModuleDtor(Module &M);
833
834 const GlobalVariable *getExcludedAliasedGlobal(const GlobalAlias &GA) const;
835 bool shouldInstrumentGlobal(GlobalVariable *G) const;
836 bool ShouldUseMachOGlobalsSection() const;
837 StringRef getGlobalMetadataSection() const;
838 void poisonOneInitializer(Function &GlobalInit, GlobalValue *ModuleName);
839 void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
840 uint64_t getMinRedzoneSizeForGlobal() const {
841 return getRedzoneSizeForScale(Mapping.Scale);
842 }
843 uint64_t getRedzoneSizeForGlobal(uint64_t SizeInBytes) const;
844 int GetAsanVersion(const Module &M) const;
845
846 bool CompileKernel;
847 bool Recover;
848 bool UseGlobalsGC;
849 bool UsePrivateAlias;
850 bool UseOdrIndicator;
851 bool UseCtorComdat;
852 AsanDtorKind DestructorKind;
853 AsanCtorKind ConstructorKind;
854 Type *IntptrTy;
855 LLVMContext *C;
856 Triple TargetTriple;
857 ShadowMapping Mapping;
858 FunctionCallee AsanPoisonGlobals;
859 FunctionCallee AsanUnpoisonGlobals;
860 FunctionCallee AsanRegisterGlobals;
861 FunctionCallee AsanUnregisterGlobals;
862 FunctionCallee AsanRegisterImageGlobals;
863 FunctionCallee AsanUnregisterImageGlobals;
864 FunctionCallee AsanRegisterElfGlobals;
865 FunctionCallee AsanUnregisterElfGlobals;
866
867 Function *AsanCtorFunction = nullptr;
868 Function *AsanDtorFunction = nullptr;
869};
870
871// Stack poisoning does not play well with exception handling.
872// When an exception is thrown, we essentially bypass the code
873// that unpoisones the stack. This is why the run-time library has
874// to intercept __cxa_throw (as well as longjmp, etc) and unpoison the entire
875// stack in the interceptor. This however does not work inside the
876// actual function which catches the exception. Most likely because the
877// compiler hoists the load of the shadow value somewhere too high.
878// This causes asan to report a non-existing bug on 453.povray.
879// It sounds like an LLVM bug.
880struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
881 Function &F;
882 AddressSanitizer &ASan;
883 DIBuilder DIB;
884 LLVMContext *C;
885 Type *IntptrTy;
886 Type *IntptrPtrTy;
887 ShadowMapping Mapping;
888
890 SmallVector<AllocaInst *, 16> StaticAllocasToMoveUp;
892
893 FunctionCallee AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
894 AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
895 FunctionCallee AsanSetShadowFunc[0x100] = {};
896 FunctionCallee AsanPoisonStackMemoryFunc, AsanUnpoisonStackMemoryFunc;
897 FunctionCallee AsanAllocaPoisonFunc, AsanAllocasUnpoisonFunc;
898
899 // Stores a place and arguments of poisoning/unpoisoning call for alloca.
900 struct AllocaPoisonCall {
901 IntrinsicInst *InsBefore;
902 AllocaInst *AI;
904 bool DoPoison;
905 };
906 SmallVector<AllocaPoisonCall, 8> DynamicAllocaPoisonCallVec;
907 SmallVector<AllocaPoisonCall, 8> StaticAllocaPoisonCallVec;
908 bool HasUntracedLifetimeIntrinsic = false;
909
910 SmallVector<AllocaInst *, 1> DynamicAllocaVec;
911 SmallVector<IntrinsicInst *, 1> StackRestoreVec;
912 AllocaInst *DynamicAllocaLayout = nullptr;
913 IntrinsicInst *LocalEscapeCall = nullptr;
914
915 bool HasInlineAsm = false;
916 bool HasReturnsTwiceCall = false;
917 bool PoisonStack;
918
919 FunctionStackPoisoner(Function &F, AddressSanitizer &ASan)
920 : F(F), ASan(ASan), DIB(*F.getParent(), /*AllowUnresolved*/ false),
921 C(ASan.C), IntptrTy(ASan.IntptrTy),
922 IntptrPtrTy(PointerType::get(IntptrTy, 0)), Mapping(ASan.Mapping),
923 PoisonStack(ClStack &&
924 !Triple(F.getParent()->getTargetTriple()).isAMDGPU()) {}
925
926 bool runOnFunction() {
927 if (!PoisonStack)
928 return false;
929
931 copyArgsPassedByValToAllocas();
932
933 // Collect alloca, ret, lifetime instructions etc.
934 for (BasicBlock *BB : depth_first(&F.getEntryBlock())) visit(*BB);
935
936 if (AllocaVec.empty() && DynamicAllocaVec.empty()) return false;
937
938 initializeCallbacks(*F.getParent());
939
940 if (HasUntracedLifetimeIntrinsic) {
941 // If there are lifetime intrinsics which couldn't be traced back to an
942 // alloca, we may not know exactly when a variable enters scope, and
943 // therefore should "fail safe" by not poisoning them.
944 StaticAllocaPoisonCallVec.clear();
945 DynamicAllocaPoisonCallVec.clear();
946 }
947
948 processDynamicAllocas();
949 processStaticAllocas();
950
951 if (ClDebugStack) {
952 LLVM_DEBUG(dbgs() << F);
953 }
954 return true;
955 }
956
957 // Arguments marked with the "byval" attribute are implicitly copied without
958 // using an alloca instruction. To produce redzones for those arguments, we
959 // copy them a second time into memory allocated with an alloca instruction.
960 void copyArgsPassedByValToAllocas();
961
962 // Finds all Alloca instructions and puts
963 // poisoned red zones around all of them.
964 // Then unpoison everything back before the function returns.
965 void processStaticAllocas();
966 void processDynamicAllocas();
967
968 void createDynamicAllocasInitStorage();
969
970 // ----------------------- Visitors.
971 /// Collect all Ret instructions, or the musttail call instruction if it
972 /// precedes the return instruction.
973 void visitReturnInst(ReturnInst &RI) {
975 RetVec.push_back(CI);
976 else
977 RetVec.push_back(&RI);
978 }
979
980 /// Collect all Resume instructions.
981 void visitResumeInst(ResumeInst &RI) { RetVec.push_back(&RI); }
982
983 /// Collect all CatchReturnInst instructions.
984 void visitCleanupReturnInst(CleanupReturnInst &CRI) { RetVec.push_back(&CRI); }
985
986 void unpoisonDynamicAllocasBeforeInst(Instruction *InstBefore,
987 Value *SavedStack) {
988 IRBuilder<> IRB(InstBefore);
989 Value *DynamicAreaPtr = IRB.CreatePtrToInt(SavedStack, IntptrTy);
990 // When we insert _asan_allocas_unpoison before @llvm.stackrestore, we
991 // need to adjust extracted SP to compute the address of the most recent
992 // alloca. We have a special @llvm.get.dynamic.area.offset intrinsic for
993 // this purpose.
994 if (!isa<ReturnInst>(InstBefore)) {
995 Function *DynamicAreaOffsetFunc = Intrinsic::getDeclaration(
996 InstBefore->getModule(), Intrinsic::get_dynamic_area_offset,
997 {IntptrTy});
998
999 Value *DynamicAreaOffset = IRB.CreateCall(DynamicAreaOffsetFunc, {});
1000
1001 DynamicAreaPtr = IRB.CreateAdd(IRB.CreatePtrToInt(SavedStack, IntptrTy),
1002 DynamicAreaOffset);
1003 }
1004
1005 IRB.CreateCall(
1006 AsanAllocasUnpoisonFunc,
1007 {IRB.CreateLoad(IntptrTy, DynamicAllocaLayout), DynamicAreaPtr});
1008 }
1009
1010 // Unpoison dynamic allocas redzones.
1011 void unpoisonDynamicAllocas() {
1012 for (Instruction *Ret : RetVec)
1013 unpoisonDynamicAllocasBeforeInst(Ret, DynamicAllocaLayout);
1014
1015 for (Instruction *StackRestoreInst : StackRestoreVec)
1016 unpoisonDynamicAllocasBeforeInst(StackRestoreInst,
1017 StackRestoreInst->getOperand(0));
1018 }
1019
1020 // Deploy and poison redzones around dynamic alloca call. To do this, we
1021 // should replace this call with another one with changed parameters and
1022 // replace all its uses with new address, so
1023 // addr = alloca type, old_size, align
1024 // is replaced by
1025 // new_size = (old_size + additional_size) * sizeof(type)
1026 // tmp = alloca i8, new_size, max(align, 32)
1027 // addr = tmp + 32 (first 32 bytes are for the left redzone).
1028 // Additional_size is added to make new memory allocation contain not only
1029 // requested memory, but also left, partial and right redzones.
1030 void handleDynamicAllocaCall(AllocaInst *AI);
1031
1032 /// Collect Alloca instructions we want (and can) handle.
1033 void visitAllocaInst(AllocaInst &AI) {
1034 // FIXME: Handle scalable vectors instead of ignoring them.
1035 if (!ASan.isInterestingAlloca(AI) ||
1036 isa<ScalableVectorType>(AI.getAllocatedType())) {
1037 if (AI.isStaticAlloca()) {
1038 // Skip over allocas that are present *before* the first instrumented
1039 // alloca, we don't want to move those around.
1040 if (AllocaVec.empty())
1041 return;
1042
1043 StaticAllocasToMoveUp.push_back(&AI);
1044 }
1045 return;
1046 }
1047
1048 if (!AI.isStaticAlloca())
1049 DynamicAllocaVec.push_back(&AI);
1050 else
1051 AllocaVec.push_back(&AI);
1052 }
1053
1054 /// Collect lifetime intrinsic calls to check for use-after-scope
1055 /// errors.
1058 if (ID == Intrinsic::stackrestore) StackRestoreVec.push_back(&II);
1059 if (ID == Intrinsic::localescape) LocalEscapeCall = &II;
1060 if (!ASan.UseAfterScope)
1061 return;
1062 if (!II.isLifetimeStartOrEnd())
1063 return;
1064 // Found lifetime intrinsic, add ASan instrumentation if necessary.
1065 auto *Size = cast<ConstantInt>(II.getArgOperand(0));
1066 // If size argument is undefined, don't do anything.
1067 if (Size->isMinusOne()) return;
1068 // Check that size doesn't saturate uint64_t and can
1069 // be stored in IntptrTy.
1070 const uint64_t SizeValue = Size->getValue().getLimitedValue();
1071 if (SizeValue == ~0ULL ||
1072 !ConstantInt::isValueValidForType(IntptrTy, SizeValue))
1073 return;
1074 // Find alloca instruction that corresponds to llvm.lifetime argument.
1075 // Currently we can only handle lifetime markers pointing to the
1076 // beginning of the alloca.
1077 AllocaInst *AI = findAllocaForValue(II.getArgOperand(1), true);
1078 if (!AI) {
1079 HasUntracedLifetimeIntrinsic = true;
1080 return;
1081 }
1082 // We're interested only in allocas we can handle.
1083 if (!ASan.isInterestingAlloca(*AI))
1084 return;
1085 bool DoPoison = (ID == Intrinsic::lifetime_end);
1086 AllocaPoisonCall APC = {&II, AI, SizeValue, DoPoison};
1087 if (AI->isStaticAlloca())
1088 StaticAllocaPoisonCallVec.push_back(APC);
1090 DynamicAllocaPoisonCallVec.push_back(APC);
1091 }
1092
1093 void visitCallBase(CallBase &CB) {
1094 if (CallInst *CI = dyn_cast<CallInst>(&CB)) {
1095 HasInlineAsm |= CI->isInlineAsm() && &CB != ASan.LocalDynamicShadow;
1096 HasReturnsTwiceCall |= CI->canReturnTwice();
1097 }
1098 }
1099
1100 // ---------------------- Helpers.
1101 void initializeCallbacks(Module &M);
1102
1103 // Copies bytes from ShadowBytes into shadow memory for indexes where
1104 // ShadowMask is not zero. If ShadowMask[i] is zero, we assume that
1105 // ShadowBytes[i] is constantly zero and doesn't need to be overwritten.
1106 void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1107 IRBuilder<> &IRB, Value *ShadowBase);
1108 void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1109 size_t Begin, size_t End, IRBuilder<> &IRB,
1110 Value *ShadowBase);
1111 void copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
1112 ArrayRef<uint8_t> ShadowBytes, size_t Begin,
1113 size_t End, IRBuilder<> &IRB, Value *ShadowBase);
1114
1115 void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);
1116
1117 Value *createAllocaForLayout(IRBuilder<> &IRB, const ASanStackFrameLayout &L,
1118 bool Dynamic);
1119 PHINode *createPHI(IRBuilder<> &IRB, Value *Cond, Value *ValueIfTrue,
1120 Instruction *ThenTerm, Value *ValueIfFalse);
1121};
1122
1123} // end anonymous namespace
1124
1126 raw_ostream &OS, function_ref<StringRef(StringRef)> MapClassName2PassName) {
1128 OS, MapClassName2PassName);
1129 OS << '<';
1130 if (Options.CompileKernel)
1131 OS << "kernel";
1132 OS << '>';
1133}
1134
1136 const AddressSanitizerOptions &Options, bool UseGlobalGC,
1137 bool UseOdrIndicator, AsanDtorKind DestructorKind,
1138 AsanCtorKind ConstructorKind)
1139 : Options(Options), UseGlobalGC(UseGlobalGC),
1140 UseOdrIndicator(UseOdrIndicator), DestructorKind(DestructorKind),
1141 ConstructorKind(ClConstructorKind) {}
1142
1145 ModuleAddressSanitizer ModuleSanitizer(M, Options.CompileKernel,
1146 Options.Recover, UseGlobalGC,
1147 UseOdrIndicator, DestructorKind,
1148 ConstructorKind);
1149 bool Modified = false;
1150 auto &FAM = MAM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
1151 const StackSafetyGlobalInfo *const SSGI =
1153 for (Function &F : M) {
1154 AddressSanitizer FunctionSanitizer(M, SSGI, Options.CompileKernel,
1155 Options.Recover, Options.UseAfterScope,
1156 Options.UseAfterReturn);
1158 Modified |= FunctionSanitizer.instrumentFunction(F, &TLI);
1159 }
1160 Modified |= ModuleSanitizer.instrumentModule(M);
1161 if (!Modified)
1162 return PreservedAnalyses::all();
1163
1165 // GlobalsAA is considered stateless and does not get invalidated unless
1166 // explicitly invalidated; PreservedAnalyses::none() is not enough. Sanitizers
1167 // make changes that require GlobalsAA to be invalidated.
1168 PA.abandon<GlobalsAA>();
1169 return PA;
1170}
1171
1173 size_t Res = llvm::countr_zero(TypeSize / 8);
1175 return Res;
1176}
1177
1178/// Check if \p G has been created by a trusted compiler pass.
1180 // Do not instrument @llvm.global_ctors, @llvm.used, etc.
1181 if (G->getName().startswith("llvm.") ||
1182 // Do not instrument gcov counter arrays.
1183 G->getName().startswith("__llvm_gcov_ctr") ||
1184 // Do not instrument rtti proxy symbols for function sanitizer.
1185 G->getName().startswith("__llvm_rtti_proxy"))
1186 return true;
1187
1188 // Do not instrument asan globals.
1189 if (G->getName().startswith(kAsanGenPrefix) ||
1190 G->getName().startswith(kSanCovGenPrefix) ||
1191 G->getName().startswith(kODRGenPrefix))
1192 return true;
1193
1194 return false;
1195}
1196
1198 Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
1199 unsigned int AddrSpace = PtrTy->getPointerAddressSpace();
1200 if (AddrSpace == 3 || AddrSpace == 5)
1201 return true;
1202 return false;
1203}
1204
1205Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
1206 // Shadow >> scale
1207 Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
1208 if (Mapping.Offset == 0) return Shadow;
1209 // (Shadow >> scale) | offset
1210 Value *ShadowBase;
1211 if (LocalDynamicShadow)
1212 ShadowBase = LocalDynamicShadow;
1213 else
1214 ShadowBase = ConstantInt::get(IntptrTy, Mapping.Offset);
1215 if (Mapping.OrShadowOffset)
1216 return IRB.CreateOr(Shadow, ShadowBase);
1217 else
1218 return IRB.CreateAdd(Shadow, ShadowBase);
1219}
1220
1221// Instrument memset/memmove/memcpy
1222void AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
1223 IRBuilder<> IRB(MI);
1224 if (isa<MemTransferInst>(MI)) {
1225 IRB.CreateCall(
1226 isa<MemMoveInst>(MI) ? AsanMemmove : AsanMemcpy,
1227 {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1228 IRB.CreatePointerCast(MI->getOperand(1), IRB.getInt8PtrTy()),
1229 IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1230 } else if (isa<MemSetInst>(MI)) {
1231 IRB.CreateCall(
1232 AsanMemset,
1233 {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1234 IRB.CreateIntCast(MI->getOperand(1), IRB.getInt32Ty(), false),
1235 IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1236 }
1237 MI->eraseFromParent();
1238}
1239
1240/// Check if we want (and can) handle this alloca.
1241bool AddressSanitizer::isInterestingAlloca(const AllocaInst &AI) {
1242 auto PreviouslySeenAllocaInfo = ProcessedAllocas.find(&AI);
1243
1244 if (PreviouslySeenAllocaInfo != ProcessedAllocas.end())
1245 return PreviouslySeenAllocaInfo->getSecond();
1246
1247 bool IsInteresting =
1248 (AI.getAllocatedType()->isSized() &&
1249 // alloca() may be called with 0 size, ignore it.
1250 ((!AI.isStaticAlloca()) || !getAllocaSizeInBytes(AI).isZero()) &&
1251 // We are only interested in allocas not promotable to registers.
1252 // Promotable allocas are common under -O0.
1254 // inalloca allocas are not treated as static, and we don't want
1255 // dynamic alloca instrumentation for them as well.
1256 !AI.isUsedWithInAlloca() &&
1257 // swifterror allocas are register promoted by ISel
1258 !AI.isSwiftError() &&
1259 // safe allocas are not interesting
1260 !(SSGI && SSGI->isSafe(AI)));
1261
1262 ProcessedAllocas[&AI] = IsInteresting;
1263 return IsInteresting;
1264}
1265
1266bool AddressSanitizer::ignoreAccess(Instruction *Inst, Value *Ptr) {
1267 // Instrument accesses from different address spaces only for AMDGPU.
1268 Type *PtrTy = cast<PointerType>(Ptr->getType()->getScalarType());
1269 if (PtrTy->getPointerAddressSpace() != 0 &&
1270 !(TargetTriple.isAMDGPU() && !isUnsupportedAMDGPUAddrspace(Ptr)))
1271 return true;
1272
1273 // Ignore swifterror addresses.
1274 // swifterror memory addresses are mem2reg promoted by instruction
1275 // selection. As such they cannot have regular uses like an instrumentation
1276 // function and it makes no sense to track them as memory.
1277 if (Ptr->isSwiftError())
1278 return true;
1279
1280 // Treat memory accesses to promotable allocas as non-interesting since they
1281 // will not cause memory violations. This greatly speeds up the instrumented
1282 // executable at -O0.
1283 if (auto AI = dyn_cast_or_null<AllocaInst>(Ptr))
1284 if (ClSkipPromotableAllocas && !isInterestingAlloca(*AI))
1285 return true;
1286
1287 if (SSGI != nullptr && SSGI->stackAccessIsSafe(*Inst) &&
1289 return true;
1290
1291 return false;
1292}
1293
1294void AddressSanitizer::getInterestingMemoryOperands(
1296 // Do not instrument the load fetching the dynamic shadow address.
1297 if (LocalDynamicShadow == I)
1298 return;
1299
1300 if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
1301 if (!ClInstrumentReads || ignoreAccess(I, LI->getPointerOperand()))
1302 return;
1303 Interesting.emplace_back(I, LI->getPointerOperandIndex(), false,
1304 LI->getType(), LI->getAlign());
1305 } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
1306 if (!ClInstrumentWrites || ignoreAccess(I, SI->getPointerOperand()))
1307 return;
1308 Interesting.emplace_back(I, SI->getPointerOperandIndex(), true,
1309 SI->getValueOperand()->getType(), SI->getAlign());
1310 } else if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
1311 if (!ClInstrumentAtomics || ignoreAccess(I, RMW->getPointerOperand()))
1312 return;
1313 Interesting.emplace_back(I, RMW->getPointerOperandIndex(), true,
1314 RMW->getValOperand()->getType(), std::nullopt);
1315 } else if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
1316 if (!ClInstrumentAtomics || ignoreAccess(I, XCHG->getPointerOperand()))
1317 return;
1318 Interesting.emplace_back(I, XCHG->getPointerOperandIndex(), true,
1319 XCHG->getCompareOperand()->getType(),
1320 std::nullopt);
1321 } else if (auto CI = dyn_cast<CallInst>(I)) {
1322 if (CI->getIntrinsicID() == Intrinsic::masked_load ||
1323 CI->getIntrinsicID() == Intrinsic::masked_store) {
1324 bool IsWrite = CI->getIntrinsicID() == Intrinsic::masked_store;
1325 // Masked store has an initial operand for the value.
1326 unsigned OpOffset = IsWrite ? 1 : 0;
1327 if (IsWrite ? !ClInstrumentWrites : !ClInstrumentReads)
1328 return;
1329
1330 auto BasePtr = CI->getOperand(OpOffset);
1331 if (ignoreAccess(I, BasePtr))
1332 return;
1333 Type *Ty = IsWrite ? CI->getArgOperand(0)->getType() : CI->getType();
1334 MaybeAlign Alignment = Align(1);
1335 // Otherwise no alignment guarantees. We probably got Undef.
1336 if (auto *Op = dyn_cast<ConstantInt>(CI->getOperand(1 + OpOffset)))
1337 Alignment = Op->getMaybeAlignValue();
1338 Value *Mask = CI->getOperand(2 + OpOffset);
1339 Interesting.emplace_back(I, OpOffset, IsWrite, Ty, Alignment, Mask);
1340 } else {
1341 for (unsigned ArgNo = 0; ArgNo < CI->arg_size(); ArgNo++) {
1342 if (!ClInstrumentByval || !CI->isByValArgument(ArgNo) ||
1343 ignoreAccess(I, CI->getArgOperand(ArgNo)))
1344 continue;
1345 Type *Ty = CI->getParamByValType(ArgNo);
1346 Interesting.emplace_back(I, ArgNo, false, Ty, Align(1));
1347 }
1348 }
1349 }
1350}
1351
1352static bool isPointerOperand(Value *V) {
1353 return V->getType()->isPointerTy() || isa<PtrToIntInst>(V);
1354}
1355
1356// This is a rough heuristic; it may cause both false positives and
1357// false negatives. The proper implementation requires cooperation with
1358// the frontend.
1360 if (ICmpInst *Cmp = dyn_cast<ICmpInst>(I)) {
1361 if (!Cmp->isRelational())
1362 return false;
1363 } else {
1364 return false;
1365 }
1366 return isPointerOperand(I->getOperand(0)) &&
1367 isPointerOperand(I->getOperand(1));
1368}
1369
1370// This is a rough heuristic; it may cause both false positives and
1371// false negatives. The proper implementation requires cooperation with
1372// the frontend.
1374 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(I)) {
1375 if (BO->getOpcode() != Instruction::Sub)
1376 return false;
1377 } else {
1378 return false;
1379 }
1380 return isPointerOperand(I->getOperand(0)) &&
1381 isPointerOperand(I->getOperand(1));
1382}
1383
1384bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
1385 // If a global variable does not have dynamic initialization we don't
1386 // have to instrument it. However, if a global does not have initializer
1387 // at all, we assume it has dynamic initializer (in other TU).
1388 if (!G->hasInitializer())
1389 return false;
1390
1391 if (G->hasSanitizerMetadata() && G->getSanitizerMetadata().IsDynInit)
1392 return false;
1393
1394 return true;
1395}
1396
1397void AddressSanitizer::instrumentPointerComparisonOrSubtraction(
1398 Instruction *I) {
1399 IRBuilder<> IRB(I);
1400 FunctionCallee F = isa<ICmpInst>(I) ? AsanPtrCmpFunction : AsanPtrSubFunction;
1401 Value *Param[2] = {I->getOperand(0), I->getOperand(1)};
1402 for (Value *&i : Param) {
1403 if (i->getType()->isPointerTy())
1404 i = IRB.CreatePointerCast(i, IntptrTy);
1405 }
1406 IRB.CreateCall(F, Param);
1407}
1408
1409static void doInstrumentAddress(AddressSanitizer *Pass, Instruction *I,
1410 Instruction *InsertBefore, Value *Addr,
1411 MaybeAlign Alignment, unsigned Granularity,
1412 TypeSize TypeStoreSize, bool IsWrite,
1413 Value *SizeArgument, bool UseCalls,
1414 uint32_t Exp) {
1415 // Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check
1416 // if the data is properly aligned.
1417 if (!TypeStoreSize.isScalable()) {
1418 const auto FixedSize = TypeStoreSize.getFixedValue();
1419 switch (FixedSize) {
1420 case 8:
1421 case 16:
1422 case 32:
1423 case 64:
1424 case 128:
1425 if (!Alignment || *Alignment >= Granularity ||
1426 *Alignment >= FixedSize / 8)
1427 return Pass->instrumentAddress(I, InsertBefore, Addr, FixedSize,
1428 IsWrite, nullptr, UseCalls, Exp);
1429 }
1430 }
1431 Pass->instrumentUnusualSizeOrAlignment(I, InsertBefore, Addr, TypeStoreSize,
1432 IsWrite, nullptr, UseCalls, Exp);
1433}
1434
1435static void instrumentMaskedLoadOrStore(AddressSanitizer *Pass,
1436 const DataLayout &DL, Type *IntptrTy,
1437 Value *Mask, Instruction *I,
1438 Value *Addr, MaybeAlign Alignment,
1439 unsigned Granularity, Type *OpType,
1440 bool IsWrite, Value *SizeArgument,
1441 bool UseCalls, uint32_t Exp) {
1442 auto *VTy = cast<VectorType>(OpType);
1443
1444 TypeSize ElemTypeSize = DL.getTypeStoreSizeInBits(VTy->getScalarType());
1445 auto Zero = ConstantInt::get(IntptrTy, 0);
1446
1447 SplitBlockAndInsertForEachLane(VTy->getElementCount(), IntptrTy, I,
1448 [&](IRBuilderBase &IRB, Value *Index) {
1449 Value *MaskElem = IRB.CreateExtractElement(Mask, Index);
1450 if (auto *MaskElemC = dyn_cast<ConstantInt>(MaskElem)) {
1451 if (MaskElemC->isZero())
1452 // No check
1453 return;
1454 // Unconditional check
1455 } else {
1456 // Conditional check
1457 Instruction *ThenTerm = SplitBlockAndInsertIfThen(MaskElem, &*IRB.GetInsertPoint(), false);
1458 IRB.SetInsertPoint(ThenTerm);
1459 }
1460
1461 Value *InstrumentedAddress = IRB.CreateGEP(VTy, Addr, {Zero, Index});
1462 doInstrumentAddress(Pass, I, &*IRB.GetInsertPoint(), InstrumentedAddress, Alignment,
1463 Granularity, ElemTypeSize, IsWrite, SizeArgument,
1464 UseCalls, Exp);
1465 });
1466}
1467
1468void AddressSanitizer::instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
1469 InterestingMemoryOperand &O, bool UseCalls,
1470 const DataLayout &DL) {
1471 Value *Addr = O.getPtr();
1472
1473 // Optimization experiments.
1474 // The experiments can be used to evaluate potential optimizations that remove
1475 // instrumentation (assess false negatives). Instead of completely removing
1476 // some instrumentation, you set Exp to a non-zero value (mask of optimization
1477 // experiments that want to remove instrumentation of this instruction).
1478 // If Exp is non-zero, this pass will emit special calls into runtime
1479 // (e.g. __asan_report_exp_load1 instead of __asan_report_load1). These calls
1480 // make runtime terminate the program in a special way (with a different
1481 // exit status). Then you run the new compiler on a buggy corpus, collect
1482 // the special terminations (ideally, you don't see them at all -- no false
1483 // negatives) and make the decision on the optimization.
1485
1486 if (ClOpt && ClOptGlobals) {
1487 // If initialization order checking is disabled, a simple access to a
1488 // dynamically initialized global is always valid.
1489 GlobalVariable *G = dyn_cast<GlobalVariable>(getUnderlyingObject(Addr));
1490 if (G && (!ClInitializers || GlobalIsLinkerInitialized(G)) &&
1491 isSafeAccess(ObjSizeVis, Addr, O.TypeStoreSize)) {
1492 NumOptimizedAccessesToGlobalVar++;
1493 return;
1494 }
1495 }
1496
1497 if (ClOpt && ClOptStack) {
1498 // A direct inbounds access to a stack variable is always valid.
1499 if (isa<AllocaInst>(getUnderlyingObject(Addr)) &&
1500 isSafeAccess(ObjSizeVis, Addr, O.TypeStoreSize)) {
1501 NumOptimizedAccessesToStackVar++;
1502 return;
1503 }
1504 }
1505
1506 if (O.IsWrite)
1507 NumInstrumentedWrites++;
1508 else
1509 NumInstrumentedReads++;
1510
1511 unsigned Granularity = 1 << Mapping.Scale;
1512 if (O.MaybeMask) {
1513 instrumentMaskedLoadOrStore(this, DL, IntptrTy, O.MaybeMask, O.getInsn(),
1514 Addr, O.Alignment, Granularity, O.OpType,
1515 O.IsWrite, nullptr, UseCalls, Exp);
1516 } else {
1517 doInstrumentAddress(this, O.getInsn(), O.getInsn(), Addr, O.Alignment,
1518 Granularity, O.TypeStoreSize, O.IsWrite, nullptr, UseCalls,
1519 Exp);
1520 }
1521}
1522
1523Instruction *AddressSanitizer::generateCrashCode(Instruction *InsertBefore,
1524 Value *Addr, bool IsWrite,
1525 size_t AccessSizeIndex,
1526 Value *SizeArgument,
1527 uint32_t Exp) {
1528 IRBuilder<> IRB(InsertBefore);
1529 Value *ExpVal = Exp == 0 ? nullptr : ConstantInt::get(IRB.getInt32Ty(), Exp);
1530 CallInst *Call = nullptr;
1531 if (SizeArgument) {
1532 if (Exp == 0)
1533 Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][0],
1534 {Addr, SizeArgument});
1535 else
1536 Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][1],
1537 {Addr, SizeArgument, ExpVal});
1538 } else {
1539 if (Exp == 0)
1540 Call =
1541 IRB.CreateCall(AsanErrorCallback[IsWrite][0][AccessSizeIndex], Addr);
1542 else
1543 Call = IRB.CreateCall(AsanErrorCallback[IsWrite][1][AccessSizeIndex],
1544 {Addr, ExpVal});
1545 }
1546
1547 Call->setCannotMerge();
1548 return Call;
1549}
1550
1551Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
1552 Value *ShadowValue,
1553 uint32_t TypeStoreSize) {
1554 size_t Granularity = static_cast<size_t>(1) << Mapping.Scale;
1555 // Addr & (Granularity - 1)
1556 Value *LastAccessedByte =
1557 IRB.CreateAnd(AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
1558 // (Addr & (Granularity - 1)) + size - 1
1559 if (TypeStoreSize / 8 > 1)
1560 LastAccessedByte = IRB.CreateAdd(
1561 LastAccessedByte, ConstantInt::get(IntptrTy, TypeStoreSize / 8 - 1));
1562 // (uint8_t) ((Addr & (Granularity-1)) + size - 1)
1563 LastAccessedByte =
1564 IRB.CreateIntCast(LastAccessedByte, ShadowValue->getType(), false);
1565 // ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue
1566 return IRB.CreateICmpSGE(LastAccessedByte, ShadowValue);
1567}
1568
1569Instruction *AddressSanitizer::instrumentAMDGPUAddress(
1570 Instruction *OrigIns, Instruction *InsertBefore, Value *Addr,
1571 uint32_t TypeStoreSize, bool IsWrite, Value *SizeArgument) {
1572 // Do not instrument unsupported addrspaces.
1574 return nullptr;
1575 Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
1576 // Follow host instrumentation for global and constant addresses.
1577 if (PtrTy->getPointerAddressSpace() != 0)
1578 return InsertBefore;
1579 // Instrument generic addresses in supported addressspaces.
1580 IRBuilder<> IRB(InsertBefore);
1581 Value *AddrLong = IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy());
1582 Value *IsShared = IRB.CreateCall(AMDGPUAddressShared, {AddrLong});
1583 Value *IsPrivate = IRB.CreateCall(AMDGPUAddressPrivate, {AddrLong});
1584 Value *IsSharedOrPrivate = IRB.CreateOr(IsShared, IsPrivate);
1585 Value *Cmp = IRB.CreateNot(IsSharedOrPrivate);
1586 Value *AddrSpaceZeroLanding =
1587 SplitBlockAndInsertIfThen(Cmp, InsertBefore, false);
1588 InsertBefore = cast<Instruction>(AddrSpaceZeroLanding);
1589 return InsertBefore;
1590}
1591
1592void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
1593 Instruction *InsertBefore, Value *Addr,
1594 uint32_t TypeStoreSize, bool IsWrite,
1595 Value *SizeArgument, bool UseCalls,
1596 uint32_t Exp) {
1597 if (TargetTriple.isAMDGPU()) {
1598 InsertBefore = instrumentAMDGPUAddress(OrigIns, InsertBefore, Addr,
1599 TypeStoreSize, IsWrite, SizeArgument);
1600 if (!InsertBefore)
1601 return;
1602 }
1603
1604 IRBuilder<> IRB(InsertBefore);
1605 size_t AccessSizeIndex = TypeStoreSizeToSizeIndex(TypeStoreSize);
1606 const ASanAccessInfo AccessInfo(IsWrite, CompileKernel, AccessSizeIndex);
1607
1608 if (UseCalls && ClOptimizeCallbacks) {
1609 const ASanAccessInfo AccessInfo(IsWrite, CompileKernel, AccessSizeIndex);
1610 Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1611 IRB.CreateCall(
1612 Intrinsic::getDeclaration(M, Intrinsic::asan_check_memaccess),
1613 {IRB.CreatePointerCast(Addr, Int8PtrTy),
1614 ConstantInt::get(Int32Ty, AccessInfo.Packed)});
1615 return;
1616 }
1617
1618 Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1619 if (UseCalls) {
1620 if (Exp == 0)
1621 IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][0][AccessSizeIndex],
1622 AddrLong);
1623 else
1624 IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][1][AccessSizeIndex],
1625 {AddrLong, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1626 return;
1627 }
1628
1629 Type *ShadowTy =
1630 IntegerType::get(*C, std::max(8U, TypeStoreSize >> Mapping.Scale));
1631 Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
1632 Value *ShadowPtr = memToShadow(AddrLong, IRB);
1633 Value *ShadowValue =
1634 IRB.CreateLoad(ShadowTy, IRB.CreateIntToPtr(ShadowPtr, ShadowPtrTy));
1635
1636 Value *Cmp = IRB.CreateIsNotNull(ShadowValue);
1637 size_t Granularity = 1ULL << Mapping.Scale;
1638 Instruction *CrashTerm = nullptr;
1639
1640 if (ClAlwaysSlowPath || (TypeStoreSize < 8 * Granularity)) {
1641 // We use branch weights for the slow path check, to indicate that the slow
1642 // path is rarely taken. This seems to be the case for SPEC benchmarks.
1644 Cmp, InsertBefore, false, MDBuilder(*C).createBranchWeights(1, 100000));
1645 assert(cast<BranchInst>(CheckTerm)->isUnconditional());
1646 BasicBlock *NextBB = CheckTerm->getSuccessor(0);
1647 IRB.SetInsertPoint(CheckTerm);
1648 Value *Cmp2 = createSlowPathCmp(IRB, AddrLong, ShadowValue, TypeStoreSize);
1649 if (Recover) {
1650 CrashTerm = SplitBlockAndInsertIfThen(Cmp2, CheckTerm, false);
1651 } else {
1652 BasicBlock *CrashBlock =
1653 BasicBlock::Create(*C, "", NextBB->getParent(), NextBB);
1654 CrashTerm = new UnreachableInst(*C, CrashBlock);
1655 BranchInst *NewTerm = BranchInst::Create(CrashBlock, NextBB, Cmp2);
1656 ReplaceInstWithInst(CheckTerm, NewTerm);
1657 }
1658 } else {
1659 CrashTerm = SplitBlockAndInsertIfThen(Cmp, InsertBefore, !Recover);
1660 }
1661
1662 Instruction *Crash = generateCrashCode(CrashTerm, AddrLong, IsWrite,
1663 AccessSizeIndex, SizeArgument, Exp);
1664 Crash->setDebugLoc(OrigIns->getDebugLoc());
1665}
1666
1667// Instrument unusual size or unusual alignment.
1668// We can not do it with a single check, so we do 1-byte check for the first
1669// and the last bytes. We call __asan_report_*_n(addr, real_size) to be able
1670// to report the actual access size.
1671void AddressSanitizer::instrumentUnusualSizeOrAlignment(
1672 Instruction *I, Instruction *InsertBefore, Value *Addr, TypeSize TypeStoreSize,
1673 bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp) {
1674 IRBuilder<> IRB(InsertBefore);
1675 Value *NumBits = IRB.CreateTypeSize(IntptrTy, TypeStoreSize);
1676 Value *Size = IRB.CreateLShr(NumBits, ConstantInt::get(IntptrTy, 3));
1677
1678 Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1679 if (UseCalls) {
1680 if (Exp == 0)
1681 IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][0],
1682 {AddrLong, Size});
1683 else
1684 IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][1],
1685 {AddrLong, Size, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1686 } else {
1687 Value *SizeMinusOne = IRB.CreateSub(Size, ConstantInt::get(IntptrTy, 1));
1688 Value *LastByte = IRB.CreateIntToPtr(
1689 IRB.CreateAdd(AddrLong, SizeMinusOne),
1690 Addr->getType());
1691 instrumentAddress(I, InsertBefore, Addr, 8, IsWrite, Size, false, Exp);
1692 instrumentAddress(I, InsertBefore, LastByte, 8, IsWrite, Size, false, Exp);
1693 }
1694}
1695
1696void ModuleAddressSanitizer::poisonOneInitializer(Function &GlobalInit,
1698 // Set up the arguments to our poison/unpoison functions.
1699 IRBuilder<> IRB(&GlobalInit.front(),
1700 GlobalInit.front().getFirstInsertionPt());
1701
1702 // Add a call to poison all external globals before the given function starts.
1703 Value *ModuleNameAddr = ConstantExpr::getPointerCast(ModuleName, IntptrTy);
1704 IRB.CreateCall(AsanPoisonGlobals, ModuleNameAddr);
1705
1706 // Add calls to unpoison all globals before each return instruction.
1707 for (auto &BB : GlobalInit)
1708 if (ReturnInst *RI = dyn_cast<ReturnInst>(BB.getTerminator()))
1709 CallInst::Create(AsanUnpoisonGlobals, "", RI);
1710}
1711
1712void ModuleAddressSanitizer::createInitializerPoisonCalls(
1714 GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
1715 if (!GV)
1716 return;
1717
1718 ConstantArray *CA = dyn_cast<ConstantArray>(GV->getInitializer());
1719 if (!CA)
1720 return;
1721
1722 for (Use &OP : CA->operands()) {
1723 if (isa<ConstantAggregateZero>(OP)) continue;
1724 ConstantStruct *CS = cast<ConstantStruct>(OP);
1725
1726 // Must have a function or null ptr.
1727 if (Function *F = dyn_cast<Function>(CS->getOperand(1))) {
1728 if (F->getName() == kAsanModuleCtorName) continue;
1729 auto *Priority = cast<ConstantInt>(CS->getOperand(0));
1730 // Don't instrument CTORs that will run before asan.module_ctor.
1731 if (Priority->getLimitedValue() <= GetCtorAndDtorPriority(TargetTriple))
1732 continue;
1733 poisonOneInitializer(*F, ModuleName);
1734 }
1735 }
1736}
1737
1738const GlobalVariable *
1739ModuleAddressSanitizer::getExcludedAliasedGlobal(const GlobalAlias &GA) const {
1740 // In case this function should be expanded to include rules that do not just
1741 // apply when CompileKernel is true, either guard all existing rules with an
1742 // 'if (CompileKernel) { ... }' or be absolutely sure that all these rules
1743 // should also apply to user space.
1744 assert(CompileKernel && "Only expecting to be called when compiling kernel");
1745
1746 const Constant *C = GA.getAliasee();
1747
1748 // When compiling the kernel, globals that are aliased by symbols prefixed
1749 // by "__" are special and cannot be padded with a redzone.
1750 if (GA.getName().startswith("__"))
1751 return dyn_cast<GlobalVariable>(C->stripPointerCastsAndAliases());
1752
1753 return nullptr;
1754}
1755
1756bool ModuleAddressSanitizer::shouldInstrumentGlobal(GlobalVariable *G) const {
1757 Type *Ty = G->getValueType();
1758 LLVM_DEBUG(dbgs() << "GLOBAL: " << *G << "\n");
1759
1760 if (G->hasSanitizerMetadata() && G->getSanitizerMetadata().NoAddress)
1761 return false;
1762 if (!Ty->isSized()) return false;
1763 if (!G->hasInitializer()) return false;
1764 // Globals in address space 1 and 4 are supported for AMDGPU.
1765 if (G->getAddressSpace() &&
1766 !(TargetTriple.isAMDGPU() && !isUnsupportedAMDGPUAddrspace(G)))
1767 return false;
1768 if (GlobalWasGeneratedByCompiler(G)) return false; // Our own globals.
1769 // Two problems with thread-locals:
1770 // - The address of the main thread's copy can't be computed at link-time.
1771 // - Need to poison all copies, not just the main thread's one.
1772 if (G->isThreadLocal()) return false;
1773 // For now, just ignore this Global if the alignment is large.
1774 if (G->getAlign() && *G->getAlign() > getMinRedzoneSizeForGlobal()) return false;
1775
1776 // For non-COFF targets, only instrument globals known to be defined by this
1777 // TU.
1778 // FIXME: We can instrument comdat globals on ELF if we are using the
1779 // GC-friendly metadata scheme.
1780 if (!TargetTriple.isOSBinFormatCOFF()) {
1781 if (!G->hasExactDefinition() || G->hasComdat())
1782 return false;
1783 } else {
1784 // On COFF, don't instrument non-ODR linkages.
1785 if (G->isInterposable())
1786 return false;
1787 }
1788
1789 // If a comdat is present, it must have a selection kind that implies ODR
1790 // semantics: no duplicates, any, or exact match.
1791 if (Comdat *C = G->getComdat()) {
1792 switch (C->getSelectionKind()) {
1793 case Comdat::Any:
1794 case Comdat::ExactMatch:
1796 break;
1797 case Comdat::Largest:
1798 case Comdat::SameSize:
1799 return false;
1800 }
1801 }
1802
1803 if (G->hasSection()) {
1804 // The kernel uses explicit sections for mostly special global variables
1805 // that we should not instrument. E.g. the kernel may rely on their layout
1806 // without redzones, or remove them at link time ("discard.*"), etc.
1807 if (CompileKernel)
1808 return false;
1809
1810 StringRef Section = G->getSection();
1811
1812 // Globals from llvm.metadata aren't emitted, do not instrument them.
1813 if (Section == "llvm.metadata") return false;
1814 // Do not instrument globals from special LLVM sections.
1815 if (Section.contains("__llvm") || Section.contains("__LLVM"))
1816 return false;
1817
1818 // Do not instrument function pointers to initialization and termination
1819 // routines: dynamic linker will not properly handle redzones.
1820 if (Section.startswith(".preinit_array") ||
1821 Section.startswith(".init_array") ||
1822 Section.startswith(".fini_array")) {
1823 return false;
1824 }
1825
1826 // Do not instrument user-defined sections (with names resembling
1827 // valid C identifiers)
1828 if (TargetTriple.isOSBinFormatELF()) {
1829 if (llvm::all_of(Section,
1830 [](char c) { return llvm::isAlnum(c) || c == '_'; }))
1831 return false;
1832 }
1833
1834 // On COFF, if the section name contains '$', it is highly likely that the
1835 // user is using section sorting to create an array of globals similar to
1836 // the way initialization callbacks are registered in .init_array and
1837 // .CRT$XCU. The ATL also registers things in .ATL$__[azm]. Adding redzones
1838 // to such globals is counterproductive, because the intent is that they
1839 // will form an array, and out-of-bounds accesses are expected.
1840 // See https://github.com/google/sanitizers/issues/305
1841 // and http://msdn.microsoft.com/en-US/en-en/library/bb918180(v=vs.120).aspx
1842 if (TargetTriple.isOSBinFormatCOFF() && Section.contains('$')) {
1843 LLVM_DEBUG(dbgs() << "Ignoring global in sorted section (contains '$'): "
1844 << *G << "\n");
1845 return false;
1846 }
1847
1848 if (TargetTriple.isOSBinFormatMachO()) {
1849 StringRef ParsedSegment, ParsedSection;
1850 unsigned TAA = 0, StubSize = 0;
1851 bool TAAParsed;
1853 Section, ParsedSegment, ParsedSection, TAA, TAAParsed, StubSize));
1854
1855 // Ignore the globals from the __OBJC section. The ObjC runtime assumes
1856 // those conform to /usr/lib/objc/runtime.h, so we can't add redzones to
1857 // them.
1858 if (ParsedSegment == "__OBJC" ||
1859 (ParsedSegment == "__DATA" && ParsedSection.startswith("__objc_"))) {
1860 LLVM_DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G << "\n");
1861 return false;
1862 }
1863 // See https://github.com/google/sanitizers/issues/32
1864 // Constant CFString instances are compiled in the following way:
1865 // -- the string buffer is emitted into
1866 // __TEXT,__cstring,cstring_literals
1867 // -- the constant NSConstantString structure referencing that buffer
1868 // is placed into __DATA,__cfstring
1869 // Therefore there's no point in placing redzones into __DATA,__cfstring.
1870 // Moreover, it causes the linker to crash on OS X 10.7
1871 if (ParsedSegment == "__DATA" && ParsedSection == "__cfstring") {
1872 LLVM_DEBUG(dbgs() << "Ignoring CFString: " << *G << "\n");
1873 return false;
1874 }
1875 // The linker merges the contents of cstring_literals and removes the
1876 // trailing zeroes.
1877 if (ParsedSegment == "__TEXT" && (TAA & MachO::S_CSTRING_LITERALS)) {
1878 LLVM_DEBUG(dbgs() << "Ignoring a cstring literal: " << *G << "\n");
1879 return false;
1880 }
1881 }
1882 }
1883
1884 if (CompileKernel) {
1885 // Globals that prefixed by "__" are special and cannot be padded with a
1886 // redzone.
1887 if (G->getName().startswith("__"))
1888 return false;
1889 }
1890
1891 return true;
1892}
1893
1894// On Mach-O platforms, we emit global metadata in a separate section of the
1895// binary in order to allow the linker to properly dead strip. This is only
1896// supported on recent versions of ld64.
1897bool ModuleAddressSanitizer::ShouldUseMachOGlobalsSection() const {
1898 if (!TargetTriple.isOSBinFormatMachO())
1899 return false;
1900
1901 if (TargetTriple.isMacOSX() && !TargetTriple.isMacOSXVersionLT(10, 11))
1902 return true;
1903 if (TargetTriple.isiOS() /* or tvOS */ && !TargetTriple.isOSVersionLT(9))
1904 return true;
1905 if (TargetTriple.isWatchOS() && !TargetTriple.isOSVersionLT(2))
1906 return true;
1907 if (TargetTriple.isDriverKit())
1908 return true;
1909
1910 return false;
1911}
1912
1913StringRef ModuleAddressSanitizer::getGlobalMetadataSection() const {
1914 switch (TargetTriple.getObjectFormat()) {
1915 case Triple::COFF: return ".ASAN$GL";
1916 case Triple::ELF: return "asan_globals";
1917 case Triple::MachO: return "__DATA,__asan_globals,regular";
1918 case Triple::Wasm:
1919 case Triple::GOFF:
1920 case Triple::SPIRV:
1921 case Triple::XCOFF:
1924 "ModuleAddressSanitizer not implemented for object file format");
1926 break;
1927 }
1928 llvm_unreachable("unsupported object format");
1929}
1930
1931void ModuleAddressSanitizer::initializeCallbacks(Module &M) {
1932 IRBuilder<> IRB(*C);
1933
1934 // Declare our poisoning and unpoisoning functions.
1935 AsanPoisonGlobals =
1936 M.getOrInsertFunction(kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy);
1937 AsanUnpoisonGlobals =
1938 M.getOrInsertFunction(kAsanUnpoisonGlobalsName, IRB.getVoidTy());
1939
1940 // Declare functions that register/unregister globals.
1941 AsanRegisterGlobals = M.getOrInsertFunction(
1942 kAsanRegisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);
1943 AsanUnregisterGlobals = M.getOrInsertFunction(
1944 kAsanUnregisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);
1945
1946 // Declare the functions that find globals in a shared object and then invoke
1947 // the (un)register function on them.
1948 AsanRegisterImageGlobals = M.getOrInsertFunction(
1949 kAsanRegisterImageGlobalsName, IRB.getVoidTy(), IntptrTy);
1950 AsanUnregisterImageGlobals = M.getOrInsertFunction(
1952
1953 AsanRegisterElfGlobals =
1954 M.getOrInsertFunction(kAsanRegisterElfGlobalsName, IRB.getVoidTy(),
1955 IntptrTy, IntptrTy, IntptrTy);
1956 AsanUnregisterElfGlobals =
1957 M.getOrInsertFunction(kAsanUnregisterElfGlobalsName, IRB.getVoidTy(),
1958 IntptrTy, IntptrTy, IntptrTy);
1959}
1960
1961// Put the metadata and the instrumented global in the same group. This ensures
1962// that the metadata is discarded if the instrumented global is discarded.
1963void ModuleAddressSanitizer::SetComdatForGlobalMetadata(
1964 GlobalVariable *G, GlobalVariable *Metadata, StringRef InternalSuffix) {
1965 Module &M = *G->getParent();
1966 Comdat *C = G->getComdat();
1967 if (!C) {
1968 if (!G->hasName()) {
1969 // If G is unnamed, it must be internal. Give it an artificial name
1970 // so we can put it in a comdat.
1971 assert(G->hasLocalLinkage());
1972 G->setName(Twine(kAsanGenPrefix) + "_anon_global");
1973 }
1974
1975 if (!InternalSuffix.empty() && G->hasLocalLinkage()) {
1976 std::string Name = std::string(G->getName());
1977 Name += InternalSuffix;
1978 C = M.getOrInsertComdat(Name);
1979 } else {
1980 C = M.getOrInsertComdat(G->getName());
1981 }
1982
1983 // Make this IMAGE_COMDAT_SELECT_NODUPLICATES on COFF. Also upgrade private
1984 // linkage to internal linkage so that a symbol table entry is emitted. This
1985 // is necessary in order to create the comdat group.
1986 if (TargetTriple.isOSBinFormatCOFF()) {
1987 C->setSelectionKind(Comdat::NoDeduplicate);
1988 if (G->hasPrivateLinkage())
1989 G->setLinkage(GlobalValue::InternalLinkage);
1990 }
1991 G->setComdat(C);
1992 }
1993
1994 assert(G->hasComdat());
1995 Metadata->setComdat(G->getComdat());
1996}
1997
1998// Create a separate metadata global and put it in the appropriate ASan
1999// global registration section.
2001ModuleAddressSanitizer::CreateMetadataGlobal(Module &M, Constant *Initializer,
2002 StringRef OriginalName) {
2003 auto Linkage = TargetTriple.isOSBinFormatMachO()
2007 M, Initializer->getType(), false, Linkage, Initializer,
2008 Twine("__asan_global_") + GlobalValue::dropLLVMManglingEscape(OriginalName));
2009 Metadata->setSection(getGlobalMetadataSection());
2010 return Metadata;
2011}
2012
2013Instruction *ModuleAddressSanitizer::CreateAsanModuleDtor(Module &M) {
2014 AsanDtorFunction = Function::createWithDefaultAttr(
2017 AsanDtorFunction->addFnAttr(Attribute::NoUnwind);
2018 // Ensure Dtor cannot be discarded, even if in a comdat.
2019 appendToUsed(M, {AsanDtorFunction});
2020 BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
2021
2022 return ReturnInst::Create(*C, AsanDtorBB);
2023}
2024
2025void ModuleAddressSanitizer::InstrumentGlobalsCOFF(
2026 IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2027 ArrayRef<Constant *> MetadataInitializers) {
2028 assert(ExtendedGlobals.size() == MetadataInitializers.size());
2029 auto &DL = M.getDataLayout();
2030
2031 SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
2032 for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2033 Constant *Initializer = MetadataInitializers[i];
2034 GlobalVariable *G = ExtendedGlobals[i];
2036 CreateMetadataGlobal(M, Initializer, G->getName());
2037 MDNode *MD = MDNode::get(M.getContext(), ValueAsMetadata::get(G));
2038 Metadata->setMetadata(LLVMContext::MD_associated, MD);
2039 MetadataGlobals[i] = Metadata;
2040
2041 // The MSVC linker always inserts padding when linking incrementally. We
2042 // cope with that by aligning each struct to its size, which must be a power
2043 // of two.
2044 unsigned SizeOfGlobalStruct = DL.getTypeAllocSize(Initializer->getType());
2045 assert(isPowerOf2_32(SizeOfGlobalStruct) &&
2046 "global metadata will not be padded appropriately");
2047 Metadata->setAlignment(assumeAligned(SizeOfGlobalStruct));
2048
2049 SetComdatForGlobalMetadata(G, Metadata, "");
2050 }
2051
2052 // Update llvm.compiler.used, adding the new metadata globals. This is
2053 // needed so that during LTO these variables stay alive.
2054 if (!MetadataGlobals.empty())
2055 appendToCompilerUsed(M, MetadataGlobals);
2056}
2057
2058void ModuleAddressSanitizer::InstrumentGlobalsELF(
2059 IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2060 ArrayRef<Constant *> MetadataInitializers,
2061 const std::string &UniqueModuleId) {
2062 assert(ExtendedGlobals.size() == MetadataInitializers.size());
2063
2064 // Putting globals in a comdat changes the semantic and potentially cause
2065 // false negative odr violations at link time. If odr indicators are used, we
2066 // keep the comdat sections, as link time odr violations will be dectected on
2067 // the odr indicator symbols.
2068 bool UseComdatForGlobalsGC = UseOdrIndicator;
2069
2070 SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
2071 for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2072 GlobalVariable *G = ExtendedGlobals[i];
2074 CreateMetadataGlobal(M, MetadataInitializers[i], G->getName());
2075 MDNode *MD = MDNode::get(M.getContext(), ValueAsMetadata::get(G));
2076 Metadata->setMetadata(LLVMContext::MD_associated, MD);
2077 MetadataGlobals[i] = Metadata;
2078
2079 if (UseComdatForGlobalsGC)
2080 SetComdatForGlobalMetadata(G, Metadata, UniqueModuleId);
2081 }
2082
2083 // Update llvm.compiler.used, adding the new metadata globals. This is
2084 // needed so that during LTO these variables stay alive.
2085 if (!MetadataGlobals.empty())
2086 appendToCompilerUsed(M, MetadataGlobals);
2087
2088 // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
2089 // to look up the loaded image that contains it. Second, we can store in it
2090 // whether registration has already occurred, to prevent duplicate
2091 // registration.
2092 //
2093 // Common linkage ensures that there is only one global per shared library.
2094 GlobalVariable *RegisteredFlag = new GlobalVariable(
2095 M, IntptrTy, false, GlobalVariable::CommonLinkage,
2098
2099 // Create start and stop symbols.
2100 GlobalVariable *StartELFMetadata = new GlobalVariable(
2101 M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
2102 "__start_" + getGlobalMetadataSection());
2104 GlobalVariable *StopELFMetadata = new GlobalVariable(
2105 M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
2106 "__stop_" + getGlobalMetadataSection());
2108
2109 // Create a call to register the globals with the runtime.
2110 if (ConstructorKind == AsanCtorKind::Global)
2111 IRB.CreateCall(AsanRegisterElfGlobals,
2112 {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
2113 IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
2114 IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
2115
2116 // We also need to unregister globals at the end, e.g., when a shared library
2117 // gets closed.
2118 if (DestructorKind != AsanDtorKind::None) {
2119 IRBuilder<> IrbDtor(CreateAsanModuleDtor(M));
2120 IrbDtor.CreateCall(AsanUnregisterElfGlobals,
2121 {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
2122 IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
2123 IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
2124 }
2125}
2126
2127void ModuleAddressSanitizer::InstrumentGlobalsMachO(
2128 IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2129 ArrayRef<Constant *> MetadataInitializers) {
2130 assert(ExtendedGlobals.size() == MetadataInitializers.size());
2131
2132 // On recent Mach-O platforms, use a structure which binds the liveness of
2133 // the global variable to the metadata struct. Keep the list of "Liveness" GV
2134 // created to be added to llvm.compiler.used
2135 StructType *LivenessTy = StructType::get(IntptrTy, IntptrTy);
2136 SmallVector<GlobalValue *, 16> LivenessGlobals(ExtendedGlobals.size());
2137
2138 for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2139 Constant *Initializer = MetadataInitializers[i];
2140 GlobalVariable *G = ExtendedGlobals[i];
2142 CreateMetadataGlobal(M, Initializer, G->getName());
2143
2144 // On recent Mach-O platforms, we emit the global metadata in a way that
2145 // allows the linker to properly strip dead globals.
2146 auto LivenessBinder =
2147 ConstantStruct::get(LivenessTy, Initializer->getAggregateElement(0u),
2149 GlobalVariable *Liveness = new GlobalVariable(
2150 M, LivenessTy, false, GlobalVariable::InternalLinkage, LivenessBinder,
2151 Twine("__asan_binder_") + G->getName());
2152 Liveness->setSection("__DATA,__asan_liveness,regular,live_support");
2153 LivenessGlobals[i] = Liveness;
2154 }
2155
2156 // Update llvm.compiler.used, adding the new liveness globals. This is
2157 // needed so that during LTO these variables stay alive. The alternative
2158 // would be to have the linker handling the LTO symbols, but libLTO
2159 // current API does not expose access to the section for each symbol.
2160 if (!LivenessGlobals.empty())
2161 appendToCompilerUsed(M, LivenessGlobals);
2162
2163 // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
2164 // to look up the loaded image that contains it. Second, we can store in it
2165 // whether registration has already occurred, to prevent duplicate
2166 // registration.
2167 //
2168 // common linkage ensures that there is only one global per shared library.
2169 GlobalVariable *RegisteredFlag = new GlobalVariable(
2170 M, IntptrTy, false, GlobalVariable::CommonLinkage,
2173
2174 if (ConstructorKind == AsanCtorKind::Global)
2175 IRB.CreateCall(AsanRegisterImageGlobals,
2176 {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2177
2178 // We also need to unregister globals at the end, e.g., when a shared library
2179 // gets closed.
2180 if (DestructorKind != AsanDtorKind::None) {
2181 IRBuilder<> IrbDtor(CreateAsanModuleDtor(M));
2182 IrbDtor.CreateCall(AsanUnregisterImageGlobals,
2183 {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2184 }
2185}
2186
2187void ModuleAddressSanitizer::InstrumentGlobalsWithMetadataArray(
2188 IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2189 ArrayRef<Constant *> MetadataInitializers) {
2190 assert(ExtendedGlobals.size() == MetadataInitializers.size());
2191 unsigned N = ExtendedGlobals.size();
2192 assert(N > 0);
2193
2194 // On platforms that don't have a custom metadata section, we emit an array
2195 // of global metadata structures.
2196 ArrayType *ArrayOfGlobalStructTy =
2197 ArrayType::get(MetadataInitializers[0]->getType(), N);
2198 auto AllGlobals = new GlobalVariable(
2199 M, ArrayOfGlobalStructTy, false, GlobalVariable::InternalLinkage,
2200 ConstantArray::get(ArrayOfGlobalStructTy, MetadataInitializers), "");
2201 if (Mapping.Scale > 3)
2202 AllGlobals->setAlignment(Align(1ULL << Mapping.Scale));
2203
2204 if (ConstructorKind == AsanCtorKind::Global)
2205 IRB.CreateCall(AsanRegisterGlobals,
2206 {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2207 ConstantInt::get(IntptrTy, N)});
2208
2209 // We also need to unregister globals at the end, e.g., when a shared library
2210 // gets closed.
2211 if (DestructorKind != AsanDtorKind::None) {
2212 IRBuilder<> IrbDtor(CreateAsanModuleDtor(M));
2213 IrbDtor.CreateCall(AsanUnregisterGlobals,
2214 {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2215 ConstantInt::get(IntptrTy, N)});
2216 }
2217}
2218
2219// This function replaces all global variables with new variables that have
2220// trailing redzones. It also creates a function that poisons
2221// redzones and inserts this function into llvm.global_ctors.
2222// Sets *CtorComdat to true if the global registration code emitted into the
2223// asan constructor is comdat-compatible.
2224bool ModuleAddressSanitizer::InstrumentGlobals(IRBuilder<> &IRB, Module &M,
2225 bool *CtorComdat) {
2226 *CtorComdat = false;
2227
2228 // Build set of globals that are aliased by some GA, where
2229 // getExcludedAliasedGlobal(GA) returns the relevant GlobalVariable.
2230 SmallPtrSet<const GlobalVariable *, 16> AliasedGlobalExclusions;
2231 if (CompileKernel) {
2232 for (auto &GA : M.aliases()) {
2233 if (const GlobalVariable *GV = getExcludedAliasedGlobal(GA))
2234 AliasedGlobalExclusions.insert(GV);
2235 }
2236 }
2237
2238 SmallVector<GlobalVariable *, 16> GlobalsToChange;
2239 for (auto &G : M.globals()) {
2240 if (!AliasedGlobalExclusions.count(&G) && shouldInstrumentGlobal(&G))
2241 GlobalsToChange.push_back(&G);
2242 }
2243
2244 size_t n = GlobalsToChange.size();
2245 if (n == 0) {
2246 *CtorComdat = true;
2247 return false;
2248 }
2249
2250 auto &DL = M.getDataLayout();
2251
2252 // A global is described by a structure
2253 // size_t beg;
2254 // size_t size;
2255 // size_t size_with_redzone;
2256 // const char *name;
2257 // const char *module_name;
2258 // size_t has_dynamic_init;
2259 // size_t padding_for_windows_msvc_incremental_link;
2260 // size_t odr_indicator;
2261 // We initialize an array of such structures and pass it to a run-time call.
2262 StructType *GlobalStructTy =
2263 StructType::get(IntptrTy, IntptrTy, IntptrTy, IntptrTy, IntptrTy,
2264 IntptrTy, IntptrTy, IntptrTy);
2266 SmallVector<Constant *, 16> Initializers(n);
2267
2268 bool HasDynamicallyInitializedGlobals = false;
2269
2270 // We shouldn't merge same module names, as this string serves as unique
2271 // module ID in runtime.
2273 M, M.getModuleIdentifier(), /*AllowMerging*/ false, kAsanGenPrefix);
2274
2275 for (size_t i = 0; i < n; i++) {
2276 GlobalVariable *G = GlobalsToChange[i];
2277
2279 if (G->hasSanitizerMetadata())
2280 MD = G->getSanitizerMetadata();
2281
2282 // The runtime library tries demangling symbol names in the descriptor but
2283 // functionality like __cxa_demangle may be unavailable (e.g.
2284 // -static-libstdc++). So we demangle the symbol names here.
2285 std::string NameForGlobal = G->getName().str();
2288 /*AllowMerging*/ true, kAsanGenPrefix);
2289
2290 Type *Ty = G->getValueType();
2291 const uint64_t SizeInBytes = DL.getTypeAllocSize(Ty);
2292 const uint64_t RightRedzoneSize = getRedzoneSizeForGlobal(SizeInBytes);
2293 Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
2294
2295 StructType *NewTy = StructType::get(Ty, RightRedZoneTy);
2296 Constant *NewInitializer = ConstantStruct::get(
2297 NewTy, G->getInitializer(), Constant::getNullValue(RightRedZoneTy));
2298
2299 // Create a new global variable with enough space for a redzone.
2300 GlobalValue::LinkageTypes Linkage = G->getLinkage();
2301 if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage)
2303 GlobalVariable *NewGlobal = new GlobalVariable(
2304 M, NewTy, G->isConstant(), Linkage, NewInitializer, "", G,
2305 G->getThreadLocalMode(), G->getAddressSpace());
2306 NewGlobal->copyAttributesFrom(G);
2307 NewGlobal->setComdat(G->getComdat());
2308 NewGlobal->setAlignment(Align(getMinRedzoneSizeForGlobal()));
2309 // Don't fold globals with redzones. ODR violation detector and redzone
2310 // poisoning implicitly creates a dependence on the global's address, so it
2311 // is no longer valid for it to be marked unnamed_addr.
2313
2314 // Move null-terminated C strings to "__asan_cstring" section on Darwin.
2315 if (TargetTriple.isOSBinFormatMachO() && !G->hasSection() &&
2316 G->isConstant()) {
2317 auto Seq = dyn_cast<ConstantDataSequential>(G->getInitializer());
2318 if (Seq && Seq->isCString())
2319 NewGlobal->setSection("__TEXT,__asan_cstring,regular");
2320 }
2321
2322 // Transfer the debug info and type metadata. The payload starts at offset
2323 // zero so we can copy the metadata over as is.
2324 NewGlobal->copyMetadata(G, 0);
2325
2326 Value *Indices2[2];
2327 Indices2[0] = IRB.getInt32(0);
2328 Indices2[1] = IRB.getInt32(0);
2329
2330 G->replaceAllUsesWith(
2331 ConstantExpr::getGetElementPtr(NewTy, NewGlobal, Indices2, true));
2332 NewGlobal->takeName(G);
2333 G->eraseFromParent();
2334 NewGlobals[i] = NewGlobal;
2335
2336 Constant *ODRIndicator = ConstantExpr::getNullValue(IRB.getInt8PtrTy());
2337 GlobalValue *InstrumentedGlobal = NewGlobal;
2338
2339 bool CanUsePrivateAliases =
2340 TargetTriple.isOSBinFormatELF() || TargetTriple.isOSBinFormatMachO() ||
2341 TargetTriple.isOSBinFormatWasm();
2342 if (CanUsePrivateAliases && UsePrivateAlias) {
2343 // Create local alias for NewGlobal to avoid crash on ODR between
2344 // instrumented and non-instrumented libraries.
2345 InstrumentedGlobal =
2347 }
2348
2349 // ODR should not happen for local linkage.
2350 if (NewGlobal->hasLocalLinkage()) {
2351 ODRIndicator = ConstantExpr::getIntToPtr(ConstantInt::get(IntptrTy, -1),
2352 IRB.getInt8PtrTy());
2353 } else if (UseOdrIndicator) {
2354 // With local aliases, we need to provide another externally visible
2355 // symbol __odr_asan_XXX to detect ODR violation.
2356 auto *ODRIndicatorSym =
2357 new GlobalVariable(M, IRB.getInt8Ty(), false, Linkage,
2359 kODRGenPrefix + NameForGlobal, nullptr,
2360 NewGlobal->getThreadLocalMode());
2361
2362 // Set meaningful attributes for indicator symbol.
2363 ODRIndicatorSym->setVisibility(NewGlobal->getVisibility());
2364 ODRIndicatorSym->setDLLStorageClass(NewGlobal->getDLLStorageClass());
2365 ODRIndicatorSym->setAlignment(Align(1));
2366 ODRIndicator = ODRIndicatorSym;
2367 }
2368
2369 Constant *Initializer = ConstantStruct::get(
2370 GlobalStructTy,
2371 ConstantExpr::getPointerCast(InstrumentedGlobal, IntptrTy),
2372 ConstantInt::get(IntptrTy, SizeInBytes),
2373 ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
2376 ConstantInt::get(IntptrTy, MD.IsDynInit),
2377 Constant::getNullValue(IntptrTy),
2378 ConstantExpr::getPointerCast(ODRIndicator, IntptrTy));
2379
2380 if (ClInitializers && MD.IsDynInit)
2381 HasDynamicallyInitializedGlobals = true;
2382
2383 LLVM_DEBUG(dbgs() << "NEW GLOBAL: " << *NewGlobal << "\n");
2384
2385 Initializers[i] = Initializer;
2386 }
2387
2388 // Add instrumented globals to llvm.compiler.used list to avoid LTO from
2389 // ConstantMerge'ing them.
2390 SmallVector<GlobalValue *, 16> GlobalsToAddToUsedList;
2391 for (size_t i = 0; i < n; i++) {
2392 GlobalVariable *G = NewGlobals[i];
2393 if (G->getName().empty()) continue;
2394 GlobalsToAddToUsedList.push_back(G);
2395 }
2396 appendToCompilerUsed(M, ArrayRef<GlobalValue *>(GlobalsToAddToUsedList));
2397
2398 std::string ELFUniqueModuleId =
2399 (UseGlobalsGC && TargetTriple.isOSBinFormatELF()) ? getUniqueModuleId(&M)
2400 : "";
2401
2402 if (!ELFUniqueModuleId.empty()) {
2403 InstrumentGlobalsELF(IRB, M, NewGlobals, Initializers, ELFUniqueModuleId);
2404 *CtorComdat = true;
2405 } else if (UseGlobalsGC && TargetTriple.isOSBinFormatCOFF()) {
2406 InstrumentGlobalsCOFF(IRB, M, NewGlobals, Initializers);
2407 } else if (UseGlobalsGC && ShouldUseMachOGlobalsSection()) {
2408 InstrumentGlobalsMachO(IRB, M, NewGlobals, Initializers);
2409 } else {
2410 InstrumentGlobalsWithMetadataArray(IRB, M, NewGlobals, Initializers);
2411 }
2412
2413 // Create calls for poisoning before initializers run and unpoisoning after.
2414 if (HasDynamicallyInitializedGlobals)
2415 createInitializerPoisonCalls(M, ModuleName);
2416
2417 LLVM_DEBUG(dbgs() << M);
2418 return true;
2419}
2420
2422ModuleAddressSanitizer::getRedzoneSizeForGlobal(uint64_t SizeInBytes) const {
2423 constexpr uint64_t kMaxRZ = 1 << 18;
2424 const uint64_t MinRZ = getMinRedzoneSizeForGlobal();
2425
2426 uint64_t RZ = 0;
2427 if (SizeInBytes <= MinRZ / 2) {
2428 // Reduce redzone size for small size objects, e.g. int, char[1]. MinRZ is
2429 // at least 32 bytes, optimize when SizeInBytes is less than or equal to
2430 // half of MinRZ.
2431 RZ = MinRZ - SizeInBytes;
2432 } else {
2433 // Calculate RZ, where MinRZ <= RZ <= MaxRZ, and RZ ~ 1/4 * SizeInBytes.
2434 RZ = std::clamp((SizeInBytes / MinRZ / 4) * MinRZ, MinRZ, kMaxRZ);
2435
2436 // Round up to multiple of MinRZ.
2437 if (SizeInBytes % MinRZ)
2438 RZ += MinRZ - (SizeInBytes % MinRZ);
2439 }
2440
2441 assert((RZ + SizeInBytes) % MinRZ == 0);
2442
2443 return RZ;
2444}
2445
2446int ModuleAddressSanitizer::GetAsanVersion(const Module &M) const {
2447 int LongSize = M.getDataLayout().getPointerSizeInBits();
2448 bool isAndroid = Triple(M.getTargetTriple()).isAndroid();
2449 int Version = 8;
2450 // 32-bit Android is one version ahead because of the switch to dynamic
2451 // shadow.
2452 Version += (LongSize == 32 && isAndroid);
2453 return Version;
2454}
2455
2456bool ModuleAddressSanitizer::instrumentModule(Module &M) {
2457 initializeCallbacks(M);
2458
2459 // Create a module constructor. A destructor is created lazily because not all
2460 // platforms, and not all modules need it.
2461 if (ConstructorKind == AsanCtorKind::Global) {
2462 if (CompileKernel) {
2463 // The kernel always builds with its own runtime, and therefore does not
2464 // need the init and version check calls.
2465 AsanCtorFunction = createSanitizerCtor(M, kAsanModuleCtorName);
2466 } else {
2467 std::string AsanVersion = std::to_string(GetAsanVersion(M));
2468 std::string VersionCheckName =
2470 std::tie(AsanCtorFunction, std::ignore) =
2472 kAsanInitName, /*InitArgTypes=*/{},
2473 /*InitArgs=*/{}, VersionCheckName);
2474 }
2475 }
2476
2477 bool CtorComdat = true;
2478 if (ClGlobals) {
2479 assert(AsanCtorFunction || ConstructorKind == AsanCtorKind::None);
2480 if (AsanCtorFunction) {
2481 IRBuilder<> IRB(AsanCtorFunction->getEntryBlock().getTerminator());
2482 InstrumentGlobals(IRB, M, &CtorComdat);
2483 } else {
2484 IRBuilder<> IRB(*C);
2485 InstrumentGlobals(IRB, M, &CtorComdat);
2486 }
2487 }
2488
2489 const uint64_t Priority = GetCtorAndDtorPriority(TargetTriple);
2490
2491 // Put the constructor and destructor in comdat if both
2492 // (1) global instrumentation is not TU-specific
2493 // (2) target is ELF.
2494 if (UseCtorComdat && TargetTriple.isOSBinFormatELF() && CtorComdat) {
2495 if (AsanCtorFunction) {
2496 AsanCtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleCtorName));
2497 appendToGlobalCtors(M, AsanCtorFunction, Priority, AsanCtorFunction);
2498 }
2499 if (AsanDtorFunction) {
2500 AsanDtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleDtorName));
2501 appendToGlobalDtors(M, AsanDtorFunction, Priority, AsanDtorFunction);
2502 }
2503 } else {
2504 if (AsanCtorFunction)
2505 appendToGlobalCtors(M, AsanCtorFunction, Priority);
2506 if (AsanDtorFunction)
2507 appendToGlobalDtors(M, AsanDtorFunction, Priority);
2508 }
2509
2510 return true;
2511}
2512
2513void AddressSanitizer::initializeCallbacks(Module &M, const TargetLibraryInfo *TLI) {
2514 IRBuilder<> IRB(*C);
2515 // Create __asan_report* callbacks.
2516 // IsWrite, TypeSize and Exp are encoded in the function name.
2517 for (int Exp = 0; Exp < 2; Exp++) {
2518 for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
2519 const std::string TypeStr = AccessIsWrite ? "store" : "load";
2520 const std::string ExpStr = Exp ? "exp_" : "";
2521 const std::string EndingStr = Recover ? "_noabort" : "";
2522
2523 SmallVector<Type *, 3> Args2 = {IntptrTy, IntptrTy};
2524 SmallVector<Type *, 2> Args1{1, IntptrTy};
2525 AttributeList AL2;
2526 AttributeList AL1;
2527 if (Exp) {
2528 Type *ExpType = Type::getInt32Ty(*C);
2529 Args2.push_back(ExpType);
2530 Args1.push_back(ExpType);
2531 if (auto AK = TLI->getExtAttrForI32Param(false)) {
2532 AL2 = AL2.addParamAttribute(*C, 2, AK);
2533 AL1 = AL1.addParamAttribute(*C, 1, AK);
2534 }
2535 }
2536 AsanErrorCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
2537 kAsanReportErrorTemplate + ExpStr + TypeStr + "_n" + EndingStr,
2538 FunctionType::get(IRB.getVoidTy(), Args2, false), AL2);
2539
2540 AsanMemoryAccessCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
2541 ClMemoryAccessCallbackPrefix + ExpStr + TypeStr + "N" + EndingStr,
2542 FunctionType::get(IRB.getVoidTy(), Args2, false), AL2);
2543
2544 for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
2545 AccessSizeIndex++) {
2546 const std::string Suffix = TypeStr + itostr(1ULL << AccessSizeIndex);
2547 AsanErrorCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2548 M.getOrInsertFunction(
2549 kAsanReportErrorTemplate + ExpStr + Suffix + EndingStr,
2550 FunctionType::get(IRB.getVoidTy(), Args1, false), AL1);
2551
2552 AsanMemoryAccessCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2553 M.getOrInsertFunction(
2554 ClMemoryAccessCallbackPrefix + ExpStr + Suffix + EndingStr,
2555 FunctionType::get(IRB.getVoidTy(), Args1, false), AL1);
2556 }
2557 }
2558 }
2559
2560 const std::string MemIntrinCallbackPrefix =
2561 (CompileKernel && !ClKasanMemIntrinCallbackPrefix)
2562 ? std::string("")
2564 AsanMemmove = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memmove",
2565 IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2566 IRB.getInt8PtrTy(), IntptrTy);
2567 AsanMemcpy = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memcpy",
2568 IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2569 IRB.getInt8PtrTy(), IntptrTy);
2570 AsanMemset = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memset",
2571 TLI->getAttrList(C, {1}, /*Signed=*/false),
2572 IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2573 IRB.getInt32Ty(), IntptrTy);
2574
2575 AsanHandleNoReturnFunc =
2576 M.getOrInsertFunction(kAsanHandleNoReturnName, IRB.getVoidTy());
2577
2578 AsanPtrCmpFunction =
2579 M.getOrInsertFunction(kAsanPtrCmp, IRB.getVoidTy(), IntptrTy, IntptrTy);
2580 AsanPtrSubFunction =
2581 M.getOrInsertFunction(kAsanPtrSub, IRB.getVoidTy(), IntptrTy, IntptrTy);
2582 if (Mapping.InGlobal)
2583 AsanShadowGlobal = M.getOrInsertGlobal("__asan_shadow",
2584 ArrayType::get(IRB.getInt8Ty(), 0));
2585
2586 AMDGPUAddressShared = M.getOrInsertFunction(
2588 AMDGPUAddressPrivate = M.getOrInsertFunction(
2590}
2591
2592bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
2593 // For each NSObject descendant having a +load method, this method is invoked
2594 // by the ObjC runtime before any of the static constructors is called.
2595 // Therefore we need to instrument such methods with a call to __asan_init
2596 // at the beginning in order to initialize our runtime before any access to
2597 // the shadow memory.
2598 // We cannot just ignore these methods, because they may call other
2599 // instrumented functions.
2600 if (F.getName().find(" load]") != std::string::npos) {
2601 FunctionCallee AsanInitFunction =
2602 declareSanitizerInitFunction(*F.getParent(), kAsanInitName, {});
2603 IRBuilder<> IRB(&F.front(), F.front().begin());
2604 IRB.CreateCall(AsanInitFunction, {});
2605 return true;
2606 }
2607 return false;
2608}
2609
2610bool AddressSanitizer::maybeInsertDynamicShadowAtFunctionEntry(Function &F) {
2611 // Generate code only when dynamic addressing is needed.
2612 if (Mapping.Offset != kDynamicShadowSentinel)
2613 return false;
2614
2615 IRBuilder<> IRB(&F.front().front());
2616 if (Mapping.InGlobal) {
2618 // An empty inline asm with input reg == output reg.
2619 // An opaque pointer-to-int cast, basically.
2621 FunctionType::get(IntptrTy, {AsanShadowGlobal->getType()}, false),
2622 StringRef(""), StringRef("=r,0"),
2623 /*hasSideEffects=*/false);
2624 LocalDynamicShadow =
2625 IRB.CreateCall(Asm, {AsanShadowGlobal}, ".asan.shadow");
2626 } else {
2627 LocalDynamicShadow =
2628 IRB.CreatePointerCast(AsanShadowGlobal, IntptrTy, ".asan.shadow");
2629 }
2630 } else {
2631 Value *GlobalDynamicAddress = F.getParent()->getOrInsertGlobal(
2633 LocalDynamicShadow = IRB.CreateLoad(IntptrTy, GlobalDynamicAddress);
2634 }
2635 return true;
2636}
2637
2638void AddressSanitizer::markEscapedLocalAllocas(Function &F) {
2639 // Find the one possible call to llvm.localescape and pre-mark allocas passed
2640 // to it as uninteresting. This assumes we haven't started processing allocas
2641 // yet. This check is done up front because iterating the use list in
2642 // isInterestingAlloca would be algorithmically slower.
2643 assert(ProcessedAllocas.empty() && "must process localescape before allocas");
2644
2645 // Try to get the declaration of llvm.localescape. If it's not in the module,
2646 // we can exit early.
2647 if (!F.getParent()->getFunction("llvm.localescape")) return;
2648
2649 // Look for a call to llvm.localescape call in the entry block. It can't be in
2650 // any other block.
2651 for (Instruction &I : F.getEntryBlock()) {
2652 IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I);
2653 if (II && II->getIntrinsicID() == Intrinsic::localescape) {
2654 // We found a call. Mark all the allocas passed in as uninteresting.
2655 for (Value *Arg : II->args()) {
2656 AllocaInst *AI = dyn_cast<AllocaInst>(Arg->stripPointerCasts());
2657 assert(AI && AI->isStaticAlloca() &&
2658 "non-static alloca arg to localescape");
2659 ProcessedAllocas[AI] = false;
2660 }
2661 break;
2662 }
2663 }
2664}
2665
2666bool AddressSanitizer::suppressInstrumentationSiteForDebug(int &Instrumented) {
2667 bool ShouldInstrument =
2668 ClDebugMin < 0 || ClDebugMax < 0 ||
2669 (Instrumented >= ClDebugMin && Instrumented <= ClDebugMax);
2670 Instrumented++;
2671 return !ShouldInstrument;
2672}
2673
2674bool AddressSanitizer::instrumentFunction(Function &F,
2675 const TargetLibraryInfo *TLI) {
2676 if (F.empty())
2677 return false;
2678 if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
2679 if (!ClDebugFunc.empty() && ClDebugFunc == F.getName()) return false;
2680 if (F.getName().startswith("__asan_")) return false;
2681
2682 bool FunctionModified = false;
2683
2684 // If needed, insert __asan_init before checking for SanitizeAddress attr.
2685 // This function needs to be called even if the function body is not
2686 // instrumented.
2687 if (maybeInsertAsanInitAtFunctionEntry(F))
2688 FunctionModified = true;
2689
2690 // Leave if the function doesn't need instrumentation.
2691 if (!F.hasFnAttribute(Attribute::SanitizeAddress)) return FunctionModified;
2692
2693 if (F.hasFnAttribute(Attribute::DisableSanitizerInstrumentation))
2694 return FunctionModified;
2695
2696 LLVM_DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
2697
2698 initializeCallbacks(*F.getParent(), TLI);
2699
2700 FunctionStateRAII CleanupObj(this);
2701
2702 FunctionModified |= maybeInsertDynamicShadowAtFunctionEntry(F);
2703
2704 // We can't instrument allocas used with llvm.localescape. Only static allocas
2705 // can be passed to that intrinsic.
2706 markEscapedLocalAllocas(F);
2707
2708 // We want to instrument every address only once per basic block (unless there
2709 // are calls between uses).
2710 SmallPtrSet<Value *, 16> TempsToInstrument;
2711 SmallVector<InterestingMemoryOperand, 16> OperandsToInstrument;
2712 SmallVector<MemIntrinsic *, 16> IntrinToInstrument;
2713 SmallVector<Instruction *, 8> NoReturnCalls;
2715 SmallVector<Instruction *, 16> PointerComparisonsOrSubtracts;
2716
2717 // Fill the set of memory operations to instrument.
2718 for (auto &BB : F) {
2719 AllBlocks.push_back(&BB);
2720 TempsToInstrument.clear();
2721 int NumInsnsPerBB = 0;
2722 for (auto &Inst : BB) {
2723 if (LooksLikeCodeInBug11395(&Inst)) return false;
2724 // Skip instructions inserted by another instrumentation.
2725 if (Inst.hasMetadata(LLVMContext::MD_nosanitize))
2726 continue;
2727 SmallVector<InterestingMemoryOperand, 1> InterestingOperands;
2728 getInterestingMemoryOperands(&Inst, InterestingOperands);
2729
2730 if (!InterestingOperands.empty()) {
2731 for (auto &Operand : InterestingOperands) {
2732 if (ClOpt && ClOptSameTemp) {
2733 Value *Ptr = Operand.getPtr();
2734 // If we have a mask, skip instrumentation if we've already
2735 // instrumented the full object. But don't add to TempsToInstrument
2736 // because we might get another load/store with a different mask.
2737 if (Operand.MaybeMask) {
2738 if (TempsToInstrument.count(Ptr))
2739 continue; // We've seen this (whole) temp in the current BB.
2740 } else {
2741 if (!TempsToInstrument.insert(Ptr).second)
2742 continue; // We've seen this temp in the current BB.
2743 }
2744 }
2745 OperandsToInstrument.push_back(Operand);
2746 NumInsnsPerBB++;
2747 }
2748 } else if (((ClInvalidPointerPairs || ClInvalidPointerCmp) &&
2752 PointerComparisonsOrSubtracts.push_back(&Inst);
2753 } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(&Inst)) {
2754 // ok, take it.
2755 IntrinToInstrument.push_back(MI);
2756 NumInsnsPerBB++;
2757 } else {
2758 if (auto *CB = dyn_cast<CallBase>(&Inst)) {
2759 // A call inside BB.
2760 TempsToInstrument.clear();
2761 if (CB->doesNotReturn())
2762 NoReturnCalls.push_back(CB);
2763 }
2764 if (CallInst *CI = dyn_cast<CallInst>(&Inst))
2766 }
2767 if (NumInsnsPerBB >= ClMaxInsnsToInstrumentPerBB) break;
2768 }
2769 }
2770
2771 bool UseCalls = (ClInstrumentationWithCallsThreshold >= 0 &&
2772 OperandsToInstrument.size() + IntrinToInstrument.size() >
2774 const DataLayout &DL = F.getParent()->getDataLayout();
2775 ObjectSizeOpts ObjSizeOpts;
2776 ObjSizeOpts.RoundToAlign = true;
2777 ObjectSizeOffsetVisitor ObjSizeVis(DL, TLI, F.getContext(), ObjSizeOpts);
2778
2779 // Instrument.
2780 int NumInstrumented = 0;
2781 for (auto &Operand : OperandsToInstrument) {
2782 if (!suppressInstrumentationSiteForDebug(NumInstrumented))
2783 instrumentMop(ObjSizeVis, Operand, UseCalls,
2784 F.getParent()->getDataLayout());
2785 FunctionModified = true;
2786 }
2787 for (auto *Inst : IntrinToInstrument) {
2788 if (!suppressInstrumentationSiteForDebug(NumInstrumented))
2789 instrumentMemIntrinsic(Inst);
2790 FunctionModified = true;
2791 }
2792
2793 FunctionStackPoisoner FSP(F, *this);
2794 bool ChangedStack = FSP.runOnFunction();
2795
2796 // We must unpoison the stack before NoReturn calls (throw, _exit, etc).
2797 // See e.g. https://github.com/google/sanitizers/issues/37
2798 for (auto *CI : NoReturnCalls) {
2799 IRBuilder<> IRB(CI);
2800 IRB.CreateCall(AsanHandleNoReturnFunc, {});
2801 }
2802
2803 for (auto *Inst : PointerComparisonsOrSubtracts) {
2804 instrumentPointerComparisonOrSubtraction(Inst);
2805 FunctionModified = true;
2806 }
2807
2808 if (ChangedStack || !NoReturnCalls.empty())
2809 FunctionModified = true;
2810
2811 LLVM_DEBUG(dbgs() << "ASAN done instrumenting: " << FunctionModified << " "
2812 << F << "\n");
2813
2814 return FunctionModified;
2815}
2816
2817// Workaround for bug 11395: we don't want to instrument stack in functions
2818// with large assembly blobs (32-bit only), otherwise reg alloc may crash.
2819// FIXME: remove once the bug 11395 is fixed.
2820bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
2821 if (LongSize != 32) return false;
2822 CallInst *CI = dyn_cast<CallInst>(I);
2823 if (!CI || !CI->isInlineAsm()) return false;
2824 if (CI->arg_size() <= 5)
2825 return false;
2826 // We have inline assembly with quite a few arguments.
2827 return true;
2828}
2829
2830void FunctionStackPoisoner::initializeCallbacks(Module &M) {
2831 IRBuilder<> IRB(*C);
2832 if (ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Always ||
2833 ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Runtime) {
2834 const char *MallocNameTemplate =
2835 ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Always
2838 for (int Index = 0; Index <= kMaxAsanStackMallocSizeClass; Index++) {
2839 std::string Suffix = itostr(Index);
2840 AsanStackMallocFunc[Index] = M.getOrInsertFunction(
2841 MallocNameTemplate + Suffix, IntptrTy, IntptrTy);
2842 AsanStackFreeFunc[Index] =
2843 M.getOrInsertFunction(kAsanStackFreeNameTemplate + Suffix,
2844 IRB.getVoidTy(), IntptrTy, IntptrTy);
2845 }
2846 }
2847 if (ASan.UseAfterScope) {
2848 AsanPoisonStackMemoryFunc = M.getOrInsertFunction(
2849 kAsanPoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
2850 AsanUnpoisonStackMemoryFunc = M.getOrInsertFunction(
2851 kAsanUnpoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
2852 }
2853
2854 for (size_t Val : {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0xf1, 0xf2,
2855 0xf3, 0xf5, 0xf8}) {
2856 std::ostringstream Name;
2858 Name << std::setw(2) << std::setfill('0') << std::hex << Val;
2859 AsanSetShadowFunc[Val] =
2860 M.getOrInsertFunction(Name.str(), IRB.getVoidTy(), IntptrTy, IntptrTy);
2861 }
2862
2863 AsanAllocaPoisonFunc = M.getOrInsertFunction(
2864 kAsanAllocaPoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
2865 AsanAllocasUnpoisonFunc = M.getOrInsertFunction(
2866 kAsanAllocasUnpoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
2867}
2868
2869void FunctionStackPoisoner::copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
2870 ArrayRef<uint8_t> ShadowBytes,
2871 size_t Begin, size_t End,
2872 IRBuilder<> &IRB,
2873 Value *ShadowBase) {
2874 if (Begin >= End)
2875 return;
2876
2877 const size_t LargestStoreSizeInBytes =
2878 std::min<size_t>(sizeof(uint64_t), ASan.LongSize / 8);
2879
2880 const bool IsLittleEndian = F.getParent()->getDataLayout().isLittleEndian();
2881
2882 // Poison given range in shadow using larges store size with out leading and
2883 // trailing zeros in ShadowMask. Zeros never change, so they need neither
2884 // poisoning nor up-poisoning. Still we don't mind if some of them get into a
2885 // middle of a store.
2886 for (size_t i = Begin; i < End;) {
2887 if (!ShadowMask[i]) {
2888 assert(!ShadowBytes[i]);
2889 ++i;
2890 continue;
2891 }
2892
2893 size_t StoreSizeInBytes = LargestStoreSizeInBytes;
2894 // Fit store size into the range.
2895 while (StoreSizeInBytes > End - i)
2896 StoreSizeInBytes /= 2;
2897
2898 // Minimize store size by trimming trailing zeros.
2899 for (size_t j = StoreSizeInBytes - 1; j && !ShadowMask[i + j]; --j) {
2900 while (j <= StoreSizeInBytes / 2)
2901 StoreSizeInBytes /= 2;
2902 }
2903
2904 uint64_t Val = 0;
2905 for (size_t j = 0; j < StoreSizeInBytes; j++) {
2906 if (IsLittleEndian)
2907 Val |= (uint64_t)ShadowBytes[i + j] << (8 * j);
2908 else
2909 Val = (Val << 8) | ShadowBytes[i + j];
2910 }
2911
2912 Value *Ptr = IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i));
2913 Value *Poison = IRB.getIntN(StoreSizeInBytes * 8, Val);
2915 Poison, IRB.CreateIntToPtr(Ptr, Poison->getType()->getPointerTo()),
2916 Align(1));
2917
2918 i += StoreSizeInBytes;
2919 }
2920}
2921
2922void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2923 ArrayRef<uint8_t> ShadowBytes,
2924 IRBuilder<> &IRB, Value *ShadowBase) {
2925 copyToShadow(ShadowMask, ShadowBytes, 0, ShadowMask.size(), IRB, ShadowBase);
2926}
2927
2928void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
2929 ArrayRef<uint8_t> ShadowBytes,
2930 size_t Begin, size_t End,
2931 IRBuilder<> &IRB, Value *ShadowBase) {
2932 assert(ShadowMask.size() == ShadowBytes.size());
2933 size_t Done = Begin;
2934 for (size_t i = Begin, j = Begin + 1; i < End; i = j++) {
2935 if (!ShadowMask[i]) {
2936 assert(!ShadowBytes[i]);
2937 continue;
2938 }
2939 uint8_t Val = ShadowBytes[i];
2940 if (!AsanSetShadowFunc[Val])
2941 continue;
2942
2943 // Skip same values.
2944 for (; j < End && ShadowMask[j] && Val == ShadowBytes[j]; ++j) {
2945 }
2946
2947 if (j - i >= ClMaxInlinePoisoningSize) {
2948 copyToShadowInline(ShadowMask, ShadowBytes, Done, i, IRB, ShadowBase);
2949 IRB.CreateCall(AsanSetShadowFunc[Val],
2950 {IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i)),
2951 ConstantInt::get(IntptrTy, j - i)});
2952 Done = j;
2953 }
2954 }
2955
2956 copyToShadowInline(ShadowMask, ShadowBytes, Done, End, IRB, ShadowBase);
2957}
2958
2959// Fake stack allocator (asan_fake_stack.h) has 11 size classes
2960// for every power of 2 from kMinStackMallocSize to kMaxAsanStackMallocSizeClass
2961static int StackMallocSizeClass(uint64_t LocalStackSize) {
2962 assert(LocalStackSize <= kMaxStackMallocSize);
2963 uint64_t MaxSize = kMinStackMallocSize;
2964 for (int i = 0;; i++, MaxSize *= 2)
2965 if (LocalStackSize <= MaxSize) return i;
2966 llvm_unreachable("impossible LocalStackSize");
2967}
2968
2969void FunctionStackPoisoner::copyArgsPassedByValToAllocas() {
2970 Instruction *CopyInsertPoint = &F.front().front();
2971 if (CopyInsertPoint == ASan.LocalDynamicShadow) {
2972 // Insert after the dynamic shadow location is determined
2973 CopyInsertPoint = CopyInsertPoint->getNextNode();
2974 assert(CopyInsertPoint);
2975 }
2976 IRBuilder<> IRB(CopyInsertPoint);
2977 const DataLayout &DL = F.getParent()->getDataLayout();
2978 for (Argument &Arg : F.args()) {
2979 if (Arg.hasByValAttr()) {
2980 Type *Ty = Arg.getParamByValType();
2981 const Align Alignment =
2982 DL.getValueOrABITypeAlignment(Arg.getParamAlign(), Ty);
2983
2984 AllocaInst *AI = IRB.CreateAlloca(
2985 Ty, nullptr,
2986 (Arg.hasName() ? Arg.getName() : "Arg" + Twine(Arg.getArgNo())) +
2987 ".byval");
2988 AI->setAlignment(Alignment);
2989 Arg.replaceAllUsesWith(AI);
2990
2991 uint64_t AllocSize = DL.getTypeAllocSize(Ty);
2992 IRB.CreateMemCpy(AI, Alignment, &Arg, Alignment, AllocSize);
2993 }
2994 }
2995}
2996
2997PHINode *FunctionStackPoisoner::createPHI(IRBuilder<> &IRB, Value *Cond,
2998 Value *ValueIfTrue,
2999 Instruction *ThenTerm,
3000 Value *ValueIfFalse) {
3001 PHINode *PHI = IRB.CreatePHI(IntptrTy, 2);
3002 BasicBlock *CondBlock = cast<Instruction>(Cond)->getParent();
3003 PHI->addIncoming(ValueIfFalse, CondBlock);
3004 BasicBlock *ThenBlock = ThenTerm->getParent();
3005 PHI->addIncoming(ValueIfTrue, ThenBlock);
3006 return PHI;
3007}
3008
3009Value *FunctionStackPoisoner::createAllocaForLayout(
3010 IRBuilder<> &IRB, const ASanStackFrameLayout &L, bool Dynamic) {
3011 AllocaInst *Alloca;
3012 if (Dynamic) {
3013 Alloca = IRB.CreateAlloca(IRB.getInt8Ty(),
3014 ConstantInt::get(IRB.getInt64Ty(), L.FrameSize),
3015 "MyAlloca");
3016 } else {
3017 Alloca = IRB.CreateAlloca(ArrayType::get(IRB.getInt8Ty(), L.FrameSize),
3018 nullptr, "MyAlloca");
3019 assert(Alloca->isStaticAlloca());
3020 }
3021 assert((ClRealignStack & (ClRealignStack - 1)) == 0);
3022 uint64_t FrameAlignment = std::max(L.FrameAlignment, uint64_t(ClRealignStack));
3023 Alloca->setAlignment(Align(FrameAlignment));
3024 return IRB.CreatePointerCast(Alloca, IntptrTy);
3025}
3026
3027void FunctionStackPoisoner::createDynamicAllocasInitStorage() {
3028 BasicBlock &FirstBB = *F.begin();
3029 IRBuilder<> IRB(dyn_cast<Instruction>(FirstBB.begin()));
3030 DynamicAllocaLayout = IRB.CreateAlloca(IntptrTy, nullptr);
3031 IRB.CreateStore(Constant::getNullValue(IntptrTy), DynamicAllocaLayout);
3032 DynamicAllocaLayout->setAlignment(Align(32));
3033}
3034
3035void FunctionStackPoisoner::processDynamicAllocas() {
3036 if (!ClInstrumentDynamicAllocas || DynamicAllocaVec.empty()) {
3037 assert(DynamicAllocaPoisonCallVec.empty());
3038 return;
3039 }
3040
3041 // Insert poison calls for lifetime intrinsics for dynamic allocas.
3042 for (const auto &APC : DynamicAllocaPoisonCallVec) {
3043 assert(APC.InsBefore);
3044 assert(APC.AI);
3045 assert(ASan.isInterestingAlloca(*APC.AI));
3046 assert(!APC.AI->isStaticAlloca());
3047
3048 IRBuilder<> IRB(APC.InsBefore);
3049 poisonAlloca(APC.AI, APC.Size, IRB, APC.DoPoison);
3050 // Dynamic allocas will be unpoisoned unconditionally below in
3051 // unpoisonDynamicAllocas.
3052 // Flag that we need unpoison static allocas.
3053 }
3054
3055 // Handle dynamic allocas.
3056 createDynamicAllocasInitStorage();
3057 for (auto &AI : DynamicAllocaVec)
3058 handleDynamicAllocaCall(AI);
3059 unpoisonDynamicAllocas();
3060}
3061
3062/// Collect instructions in the entry block after \p InsBefore which initialize
3063/// permanent storage for a function argument. These instructions must remain in
3064/// the entry block so that uninitialized values do not appear in backtraces. An
3065/// added benefit is that this conserves spill slots. This does not move stores
3066/// before instrumented / "interesting" allocas.
3068 AddressSanitizer &ASan, Instruction &InsBefore,
3069 SmallVectorImpl<Instruction *> &InitInsts) {
3070 Instruction *Start = InsBefore.getNextNonDebugInstruction();
3071 for (Instruction *It = Start; It; It = It->getNextNonDebugInstruction()) {
3072 // Argument initialization looks like:
3073 // 1) store <Argument>, <Alloca> OR
3074 // 2) <CastArgument> = cast <Argument> to ...
3075 // store <CastArgument> to <Alloca>
3076 // Do not consider any other kind of instruction.
3077 //
3078 // Note: This covers all known cases, but may not be exhaustive. An
3079 // alternative to pattern-matching stores is to DFS over all Argument uses:
3080 // this might be more general, but is probably much more complicated.
3081 if (isa<AllocaInst>(It) || isa<CastInst>(It))
3082 continue;
3083 if (auto *Store = dyn_cast<StoreInst>(It)) {
3084 // The store destination must be an alloca that isn't interesting for
3085 // ASan to instrument. These are moved up before InsBefore, and they're
3086 // not interesting because allocas for arguments can be mem2reg'd.
3087 auto *Alloca = dyn_cast<AllocaInst>(Store->getPointerOperand());
3088 if (!Alloca || ASan.isInterestingAlloca(*Alloca))
3089 continue;
3090
3091 Value *Val = Store->getValueOperand();
3092 bool IsDirectArgInit = isa<Argument>(Val);
3093 bool IsArgInitViaCast =
3094 isa<CastInst>(Val) &&
3095 isa<Argument>(cast<CastInst>(Val)->getOperand(0)) &&
3096 // Check that the cast appears directly before the store. Otherwise
3097 // moving the cast before InsBefore may break the IR.
3098 Val == It->getPrevNonDebugInstruction();
3099 bool IsArgInit = IsDirectArgInit || IsArgInitViaCast;
3100 if (!IsArgInit)
3101 continue;
3102
3103 if (IsArgInitViaCast)
3104 InitInsts.push_back(cast<Instruction>(Val));
3105 InitInsts.push_back(Store);
3106 continue;
3107 }
3108
3109 // Do not reorder past unknown instructions: argument initialization should
3110 // only involve casts and stores.
3111 return;
3112 }
3113}
3114
3115void FunctionStackPoisoner::processStaticAllocas() {
3116 if (AllocaVec.empty()) {
3117 assert(StaticAllocaPoisonCallVec.empty());
3118 return;
3119 }
3120
3121 int StackMallocIdx = -1;
3122 DebugLoc EntryDebugLocation;
3123 if (auto SP = F.getSubprogram())
3124 EntryDebugLocation =
3125 DILocation::get(SP->getContext(), SP->getScopeLine(), 0, SP);
3126
3127 Instruction *InsBefore = AllocaVec[0];
3128 IRBuilder<> IRB(InsBefore);
3129
3130 // Make sure non-instrumented allocas stay in the entry block. Otherwise,
3131 // debug info is broken, because only entry-block allocas are treated as
3132 // regular stack slots.
3133 auto InsBeforeB = InsBefore->getParent();
3134 assert(InsBeforeB == &F.getEntryBlock());
3135 for (auto *AI : StaticAllocasToMoveUp)
3136 if (AI->getParent() == InsBeforeB)
3137 AI->moveBefore(InsBefore);
3138
3139 // Move stores of arguments into entry-block allocas as well. This prevents
3140 // extra stack slots from being generated (to house the argument values until
3141 // they can be stored into the allocas). This also prevents uninitialized
3142 // values from being shown in backtraces.
3143 SmallVector<Instruction *, 8> ArgInitInsts;
3144 findStoresToUninstrumentedArgAllocas(ASan, *InsBefore, ArgInitInsts);
3145 for (Instruction *ArgInitInst : ArgInitInsts)
3146 ArgInitInst->moveBefore(InsBefore);
3147
3148 // If we have a call to llvm.localescape, keep it in the entry block.
3149 if (LocalEscapeCall) LocalEscapeCall->moveBefore(InsBefore);
3150
3152 SVD.reserve(AllocaVec.size());
3153 for (AllocaInst *AI : AllocaVec) {
3155 ASan.getAllocaSizeInBytes(*AI),
3156 0,
3157 AI->getAlign().value(),
3158 AI,
3159 0,
3160 0};
3161 SVD.push_back(D);
3162 }
3163
3164 // Minimal header size (left redzone) is 4 pointers,
3165 // i.e. 32 bytes on 64-bit platforms and 16 bytes in 32-bit platforms.
3166 uint64_t Granularity = 1ULL << Mapping.Scale;
3167 uint64_t MinHeaderSize = std::max((uint64_t)ASan.LongSize / 2, Granularity);
3168 const ASanStackFrameLayout &L =
3169 ComputeASanStackFrameLayout(SVD, Granularity, MinHeaderSize);
3170
3171 // Build AllocaToSVDMap for ASanStackVariableDescription lookup.
3173 for (auto &Desc : SVD)
3174 AllocaToSVDMap[Desc.AI] = &Desc;
3175
3176 // Update SVD with information from lifetime intrinsics.
3177 for (const auto &APC : StaticAllocaPoisonCallVec) {
3178 assert(APC.InsBefore);
3179 assert(APC.AI);
3180 assert(ASan.isInterestingAlloca(*APC.AI));
3181 assert(APC.AI->isStaticAlloca());
3182
3183 ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
3184 Desc.LifetimeSize = Desc.Size;
3185 if (const DILocation *FnLoc = EntryDebugLocation.get()) {
3186 if (const DILocation *LifetimeLoc = APC.InsBefore->getDebugLoc().get()) {
3187 if (LifetimeLoc->getFile() == FnLoc->getFile())
3188 if (unsigned Line = LifetimeLoc->getLine())
3189 Desc.Line = std::min(Desc.Line ? Desc.Line : Line, Line);
3190 }
3191 }
3192 }
3193
3194 auto DescriptionString = ComputeASanStackFrameDescription(SVD);
3195 LLVM_DEBUG(dbgs() << DescriptionString << " --- " << L.FrameSize << "\n");
3196 uint64_t LocalStackSize = L.FrameSize;
3197 bool DoStackMalloc =
3198 ASan.UseAfterReturn != AsanDetectStackUseAfterReturnMode::Never &&
3199 !ASan.CompileKernel && LocalStackSize <= kMaxStackMallocSize;
3200 bool DoDynamicAlloca = ClDynamicAllocaStack;
3201 // Don't do dynamic alloca or stack malloc if:
3202 // 1) There is inline asm: too often it makes assumptions on which registers
3203 // are available.
3204 // 2) There is a returns_twice call (typically setjmp), which is
3205 // optimization-hostile, and doesn't play well with introduced indirect
3206 // register-relative calculation of local variable addresses.
3207 DoDynamicAlloca &= !HasInlineAsm && !HasReturnsTwiceCall;
3208 DoStackMalloc &= !HasInlineAsm && !HasReturnsTwiceCall;
3209
3210 Value *StaticAlloca =
3211 DoDynamicAlloca ? nullptr : createAllocaForLayout(IRB, L, false);
3212
3213 Value *FakeStack;
3214 Value *LocalStackBase;
3215 Value *LocalStackBaseAlloca;
3216 uint8_t DIExprFlags = DIExpression::ApplyOffset;
3217
3218 if (DoStackMalloc) {
3219 LocalStackBaseAlloca =
3220 IRB.CreateAlloca(IntptrTy, nullptr, "asan_local_stack_base");
3221 if (ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Runtime) {
3222 // void *FakeStack = __asan_option_detect_stack_use_after_return
3223 // ? __asan_stack_malloc_N(LocalStackSize)
3224 // : nullptr;
3225 // void *LocalStackBase = (FakeStack) ? FakeStack :
3226 // alloca(LocalStackSize);
3227 Constant *OptionDetectUseAfterReturn = F.getParent()->getOrInsertGlobal(
3229 Value *UseAfterReturnIsEnabled = IRB.CreateICmpNE(
3230 IRB.CreateLoad(IRB.getInt32Ty(), OptionDetectUseAfterReturn),
3232 Instruction *Term =
3233 SplitBlockAndInsertIfThen(UseAfterReturnIsEnabled, InsBefore, false);
3234 IRBuilder<> IRBIf(Term);
3235 StackMallocIdx = StackMallocSizeClass(LocalStackSize);
3236 assert(StackMallocIdx <= kMaxAsanStackMallocSizeClass);
3237 Value *FakeStackValue =
3238 IRBIf.CreateCall(AsanStackMallocFunc[StackMallocIdx],
3239 ConstantInt::get(IntptrTy, LocalStackSize));
3240 IRB.SetInsertPoint(InsBefore);
3241 FakeStack = createPHI(IRB, UseAfterReturnIsEnabled, FakeStackValue, Term,
3242 ConstantInt::get(IntptrTy, 0));
3243 } else {
3244 // assert(ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode:Always)
3245 // void *FakeStack = __asan_stack_malloc_N(LocalStackSize);
3246 // void *LocalStackBase = (FakeStack) ? FakeStack :
3247 // alloca(LocalStackSize);
3248 StackMallocIdx = StackMallocSizeClass(LocalStackSize);
3249 FakeStack = IRB.CreateCall(AsanStackMallocFunc[StackMallocIdx],
3250 ConstantInt::get(IntptrTy, LocalStackSize));
3251 }
3252 Value *NoFakeStack =
3253 IRB.CreateICmpEQ(FakeStack, Constant::getNullValue(IntptrTy));
3254 Instruction *Term =
3255 SplitBlockAndInsertIfThen(NoFakeStack, InsBefore, false);
3256 IRBuilder<> IRBIf(Term);
3257 Value *AllocaValue =
3258 DoDynamicAlloca ? createAllocaForLayout(IRBIf, L, true) : StaticAlloca;
3259
3260 IRB.SetInsertPoint(InsBefore);
3261 LocalStackBase = createPHI(IRB, NoFakeStack, AllocaValue, Term, FakeStack);
3262 IRB.CreateStore(LocalStackBase, LocalStackBaseAlloca);
3263 DIExprFlags |= DIExpression::DerefBefore;
3264 } else {
3265 // void *FakeStack = nullptr;
3266 // void *LocalStackBase = alloca(LocalStackSize);
3267 FakeStack = ConstantInt::get(IntptrTy, 0);
3268 LocalStackBase =
3269 DoDynamicAlloca ? createAllocaForLayout(IRB, L, true) : StaticAlloca;
3270 LocalStackBaseAlloca = LocalStackBase;
3271 }
3272
3273 // It shouldn't matter whether we pass an `alloca` or a `ptrtoint` as the
3274 // dbg.declare address opereand, but passing a `ptrtoint` seems to confuse
3275 // later passes and can result in dropped variable coverage in debug info.
3276 Value *LocalStackBaseAllocaPtr =
3277 isa<PtrToIntInst>(LocalStackBaseAlloca)
3278 ? cast<PtrToIntInst>(LocalStackBaseAlloca)->getPointerOperand()
3279 : LocalStackBaseAlloca;
3280 assert(isa<AllocaInst>(LocalStackBaseAllocaPtr) &&
3281 "Variable descriptions relative to ASan stack base will be dropped");
3282
3283 // Replace Alloca instructions with base+offset.
3284 for (const auto &Desc : SVD) {
3285 AllocaInst *AI = Desc.AI;
3286 replaceDbgDeclare(AI, LocalStackBaseAllocaPtr, DIB, DIExprFlags,
3287 Desc.Offset);
3288 Value *NewAllocaPtr = IRB.CreateIntToPtr(
3289 IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Desc.Offset)),
3290 AI->getType());
3291 AI->replaceAllUsesWith(NewAllocaPtr);
3292 }
3293
3294 // The left-most redzone has enough space for at least 4 pointers.
3295 // Write the Magic value to redzone[0].
3296 Value *BasePlus0 = IRB.CreateIntToPtr(LocalStackBase, IntptrPtrTy);
3298 BasePlus0);
3299 // Write the frame description constant to redzone[1].
3300 Value *BasePlus1 = IRB.CreateIntToPtr(
3301 IRB.CreateAdd(LocalStackBase,
3302 ConstantInt::get(IntptrTy, ASan.LongSize / 8)),
3303 IntptrPtrTy);
3304 GlobalVariable *StackDescriptionGlobal =
3305 createPrivateGlobalForString(*F.getParent(), DescriptionString,
3306 /*AllowMerging*/ true, kAsanGenPrefix);
3307 Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal, IntptrTy);
3308 IRB.CreateStore(Description, BasePlus1);
3309 // Write the PC to redzone[2].
3310 Value *BasePlus2 = IRB.CreateIntToPtr(
3311 IRB.CreateAdd(LocalStackBase,
3312 ConstantInt::get(IntptrTy, 2 * ASan.LongSize / 8)),
3313 IntptrPtrTy);
3314 IRB.CreateStore(IRB.CreatePointerCast(&F, IntptrTy), BasePlus2);
3315
3316 const auto &ShadowAfterScope = GetShadowBytesAfterScope(SVD, L);
3317
3318 // Poison the stack red zones at the entry.
3319 Value *ShadowBase = ASan.memToShadow(LocalStackBase, IRB);
3320 // As mask we must use most poisoned case: red zones and after scope.
3321 // As bytes we can use either the same or just red zones only.
3322 copyToShadow(ShadowAfterScope, ShadowAfterScope, IRB, ShadowBase);
3323
3324 if (!StaticAllocaPoisonCallVec.empty()) {
3325 const auto &ShadowInScope = GetShadowBytes(SVD, L);
3326
3327 // Poison static allocas near lifetime intrinsics.
3328 for (const auto &APC : StaticAllocaPoisonCallVec) {
3329 const ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
3330 assert(Desc.Offset % L.Granularity == 0);
3331 size_t Begin = Desc.Offset / L.Granularity;
3332 size_t End = Begin + (APC.Size + L.Granularity - 1) / L.Granularity;
3333
3334 IRBuilder<> IRB(APC.InsBefore);
3335 copyToShadow(ShadowAfterScope,
3336 APC.DoPoison ? ShadowAfterScope : ShadowInScope, Begin, End,
3337 IRB, ShadowBase);
3338 }
3339 }
3340
3341 SmallVector<uint8_t, 64> ShadowClean(ShadowAfterScope.size(), 0);
3342 SmallVector<uint8_t, 64> ShadowAfterReturn;
3343
3344 // (Un)poison the stack before all ret instructions.
3345 for (Instruction *Ret : RetVec) {
3346 IRBuilder<> IRBRet(Ret);
3347 // Mark the current frame as retired.
3348 IRBRet.CreateStore(ConstantInt::get(IntptrTy, kRetiredStackFrameMagic),
3349 BasePlus0);
3350 if (DoStackMalloc) {
3351 assert(StackMallocIdx >= 0);
3352 // if FakeStack != 0 // LocalStackBase == FakeStack
3353 // // In use-after-return mode, poison the whole stack frame.
3354 // if StackMallocIdx <= 4
3355 // // For small sizes inline the whole thing:
3356 // memset(ShadowBase, kAsanStackAfterReturnMagic, ShadowSize);
3357 // **SavedFlagPtr(FakeStack) = 0
3358 // else
3359 // __asan_stack_free_N(FakeStack, LocalStackSize)
3360 // else
3361 // <This is not a fake stack; unpoison the redzones>
3362 Value *Cmp =
3363 IRBRet.CreateICmpNE(FakeStack, Constant::getNullValue(IntptrTy));
3364 Instruction *ThenTerm, *ElseTerm;
3365 SplitBlockAndInsertIfThenElse(Cmp, Ret, &ThenTerm, &ElseTerm);
3366
3367 IRBuilder<> IRBPoison(ThenTerm);
3368 if (StackMallocIdx <= 4) {
3369 int ClassSize = kMinStackMallocSize << StackMallocIdx;
3370 ShadowAfterReturn.resize(ClassSize / L.Granularity,
3372 copyToShadow(ShadowAfterReturn, ShadowAfterReturn, IRBPoison,
3373 ShadowBase);
3374 Value *SavedFlagPtrPtr = IRBPoison.CreateAdd(
3375 FakeStack,
3376 ConstantInt::get(IntptrTy, ClassSize - ASan.LongSize / 8));
3377 Value *SavedFlagPtr = IRBPoison.CreateLoad(
3378 IntptrTy, IRBPoison.CreateIntToPtr(SavedFlagPtrPtr, IntptrPtrTy));
3379 IRBPoison.CreateStore(
3380 Constant::getNullValue(IRBPoison.getInt8Ty()),
3381 IRBPoison.CreateIntToPtr(SavedFlagPtr, IRBPoison.getInt8PtrTy()));
3382 } else {
3383 // For larger frames call __asan_stack_free_*.
3384 IRBPoison.CreateCall(
3385 AsanStackFreeFunc[StackMallocIdx],
3386 {FakeStack, ConstantInt::get(IntptrTy, LocalStackSize)});
3387 }
3388
3389 IRBuilder<> IRBElse(ElseTerm);
3390 copyToShadow(ShadowAfterScope, ShadowClean, IRBElse, ShadowBase);
3391 } else {
3392 copyToShadow(ShadowAfterScope, ShadowClean, IRBRet, ShadowBase);
3393 }
3394 }
3395
3396 // We are done. Remove the old unused alloca instructions.
3397 for (auto *AI : AllocaVec)
3398 AI->eraseFromParent();
3399}
3400
3401void FunctionStackPoisoner::poisonAlloca(Value *V, uint64_t Size,
3402 IRBuilder<> &IRB, bool DoPoison) {
3403 // For now just insert the call to ASan runtime.
3404 Value *AddrArg = IRB.CreatePointerCast(V, IntptrTy);
3405 Value *SizeArg = ConstantInt::get(IntptrTy, Size);
3406 IRB.CreateCall(
3407 DoPoison ? AsanPoisonStackMemoryFunc : AsanUnpoisonStackMemoryFunc,
3408 {AddrArg, SizeArg});
3409}
3410
3411// Handling llvm.lifetime intrinsics for a given %alloca:
3412// (1) collect all llvm.lifetime.xxx(%size, %value) describing the alloca.
3413// (2) if %size is constant, poison memory for llvm.lifetime.end (to detect
3414// invalid accesses) and unpoison it for llvm.lifetime.start (the memory
3415// could be poisoned by previous llvm.lifetime.end instruction, as the
3416// variable may go in and out of scope several times, e.g. in loops).
3417// (3) if we poisoned at least one %alloca in a function,
3418// unpoison the whole stack frame at function exit.
3419void FunctionStackPoisoner::handleDynamicAllocaCall(AllocaInst *AI) {
3420 IRBuilder<> IRB(AI);
3421
3422 const Align Alignment = std::max(Align(kAllocaRzSize), AI->getAlign());
3423 const uint64_t AllocaRedzoneMask = kAllocaRzSize - 1;
3424
3425 Value *Zero = Constant::getNullValue(IntptrTy);
3426 Value *AllocaRzSize = ConstantInt::get(IntptrTy, kAllocaRzSize);
3427 Value *AllocaRzMask = ConstantInt::get(IntptrTy, AllocaRedzoneMask);
3428
3429 // Since we need to extend alloca with additional memory to locate
3430 // redzones, and OldSize is number of allocated blocks with
3431 // ElementSize size, get allocated memory size in bytes by
3432 // OldSize * ElementSize.
3433 const unsigned ElementSize =
3434 F.getParent()->getDataLayout().getTypeAllocSize(AI->getAllocatedType());
3435 Value *OldSize =
3436 IRB.CreateMul(IRB.CreateIntCast(AI->getArraySize(), IntptrTy, false),
3437 ConstantInt::get(IntptrTy, ElementSize));
3438
3439 // PartialSize = OldSize % 32
3440 Value *PartialSize = IRB.CreateAnd(OldSize, AllocaRzMask);
3441
3442 // Misalign = kAllocaRzSize - PartialSize;
3443 Value *Misalign = IRB.CreateSub(AllocaRzSize, PartialSize);
3444
3445 // PartialPadding = Misalign != kAllocaRzSize ? Misalign : 0;
3446 Value *Cond = IRB.CreateICmpNE(Misalign, AllocaRzSize);
3447 Value *PartialPadding = IRB.CreateSelect(Cond, Misalign, Zero);
3448
3449 // AdditionalChunkSize = Alignment + PartialPadding + kAllocaRzSize
3450 // Alignment is added to locate left redzone, PartialPadding for possible
3451 // partial redzone and kAllocaRzSize for right redzone respectively.
3452 Value *AdditionalChunkSize = IRB.CreateAdd(
3453 ConstantInt::get(IntptrTy, Alignment.value() + kAllocaRzSize),
3454 PartialPadding);
3455
3456 Value *NewSize = IRB.CreateAdd(OldSize, AdditionalChunkSize);
3457
3458 // Insert new alloca with new NewSize and Alignment params.
3459 AllocaInst *NewAlloca = IRB.CreateAlloca(IRB.getInt8Ty(), NewSize);
3460 NewAlloca->setAlignment(Alignment);
3461
3462 // NewAddress = Address + Alignment
3463 Value *NewAddress =
3464 IRB.CreateAdd(IRB.CreatePtrToInt(NewAlloca, IntptrTy),
3465 ConstantInt::get(IntptrTy, Alignment.value()));
3466
3467 // Insert __asan_alloca_poison call for new created alloca.
3468 IRB.CreateCall(AsanAllocaPoisonFunc, {NewAddress, OldSize});
3469
3470 // Store the last alloca's address to DynamicAllocaLayout. We'll need this
3471 // for unpoisoning stuff.
3472 IRB.CreateStore(IRB.CreatePtrToInt(NewAlloca, IntptrTy), DynamicAllocaLayout);
3473
3474 Value *NewAddressPtr = IRB.CreateIntToPtr(NewAddress, AI->getType());
3475
3476 // Replace all uses of AddessReturnedByAlloca with NewAddressPtr.
3477 AI->replaceAllUsesWith(NewAddressPtr);
3478
3479 // We are done. Erase old alloca from parent.
3480 AI->eraseFromParent();
3481}
3482
3483// isSafeAccess returns true if Addr is always inbounds with respect to its
3484// base object. For example, it is a field access or an array access with
3485// constant inbounds index.
3486bool AddressSanitizer::isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis,
3487 Value *Addr, TypeSize TypeStoreSize) const {
3488 if (TypeStoreSize.isScalable())
3489 // TODO: We can use vscale_range to convert a scalable value to an
3490 // upper bound on the access size.
3491 return false;
3492 SizeOffsetType SizeOffset = ObjSizeVis.compute(Addr);
3493 if (!ObjSizeVis.bothKnown(SizeOffset)) return false;
3494 uint64_t Size = SizeOffset.first.getZExtValue();
3495 int64_t Offset = SizeOffset.second.getSExtValue();
3496 // Three checks are required to ensure safety:
3497 // . Offset >= 0 (since the offset is given from the base ptr)
3498 // . Size >= Offset (unsigned)
3499 // . Size - Offset >= NeededSize (unsigned)
3500 return Offset >= 0 && Size >= uint64_t(Offset) &&
3501 Size - uint64_t(Offset) >= TypeStoreSize / 8;
3502}
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"))
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 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 void doInstrumentAddress(AddressSanitizer *Pass, Instruction *I, Instruction *InsertBefore, Value *Addr, MaybeAlign Alignment, unsigned Granularity, TypeSize TypeStoreSize, bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp)
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
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))
static size_t TypeStoreSizeToSizeIndex(uint32_t TypeSize)
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...
#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
#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())
raw_pwrite_stream & OS
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.
static SymbolRef::Type getType(const Symbol *Sym)
Definition: TapiFile.cpp:40
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
std::optional< TypeSize > getAllocationSize(const DataLayout &DL) const
Get allocation size in bytes.
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:658
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:576
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:1186
bool isInlineAsm() const
Check if this call is an inline asm statement.
Definition: InstrTypes.h:1476
Value * getArgOperand(unsigned i) const
Definition: InstrTypes.h:1353
iterator_range< User::op_iterator > args()
Iteration adapter for range-for loops.
Definition: InstrTypes.h:1344
bool doesNotReturn() const
Determine if the call cannot return.
Definition: InstrTypes.h:1911
unsigned arg_size() const
Definition: InstrTypes.h:1351
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:1250
static Constant * getIntToPtr(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:2214
static Constant * getPointerCast(Constant *C, Type *Ty)
Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant expression.
Definition: Constants.cpp:2040
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:1228
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:1519
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:888
static Constant * get(StructType *T, ArrayRef< Constant * > V)
Definition: Constants.cpp:1315
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:110
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:763
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:336
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.
Common base class shared among various IRBuilders.
Definition: IRBuilder.h:94
AllocaInst * CreateAlloca(Type *Ty, unsigned AddrSpace, Value *ArraySize=nullptr, const Twine &Name="")
Definition: IRBuilder.h:1696
IntegerType * getInt1Ty()
Fetch the type representing a single bit.
Definition: IRBuilder.h:497
Value * CreatePointerCast(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:2062
Value * CreateICmpSGE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:2158
Value * CreateSelect(Value *C, Value *True, Value *False, const Twine &Name="", Instruction *MDFrom=nullptr)
Definition: IRBuilder.cpp:1136
BasicBlock::iterator GetInsertPoint() const
Definition: IRBuilder.h:175
Value * CreateIntToPtr(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:2011
Value * CreateTypeSize(Type *DstType, TypeSize Size)
Create an expression which evaluates to the number of units in Size at runtime.
Definition: IRBuilder.cpp:115
Value * CreateLShr(Value *LHS, Value *RHS, const Twine &Name="", bool isExact=false)
Definition: IRBuilder.h:1360
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:2134
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:2286
Value * CreateNot(Value *V, const Twine &Name="")
Definition: IRBuilder.h:1672
Value * CreateICmpEQ(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:2130
Value * CreateSub(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1267
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:1713
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:1398
StoreInst * CreateStore(Value *Val, Value *Ptr, bool isVolatile=false)
Definition: IRBuilder.h:1726
Value * CreateAdd(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1250
Value * CreatePtrToInt(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:2006
Value * CreateIsNotNull(Value *Arg, const Twine &Name="")
Return a boolean value testing if Arg != 0.
Definition: IRBuilder.h:2438
Value * CreateOr(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1420
Value * CreateIntCast(Value *V, Type *DestTy, bool isSigned, const Twine &Name="")
Definition: IRBuilder.h:2085
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:1749
CallInst * CreateCall(FunctionType *FTy, Value *Callee, ArrayRef< Value * > Args=std::nullopt, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:2301
Value * CreateGEP(Type *Ty, Value *Ptr, ArrayRef< Value * > IdxList, const Twine &Name="", bool IsInBounds=false)
Definition: IRBuilder.h:1789
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:1284
This provides a uniform API for creating instructions and inserting them into a basic block: either a...
Definition: IRBuilder.h:2558
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:331
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:426
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:727
bool isThumb() const
Tests whether the target is Thumb (little and big endian).
Definition: Triple.h:784
bool isDriverKit() const
Is this an Apple DriverKit triple.
Definition: Triple.h:514
bool isOSNetBSD() const
Definition: Triple.h:537
bool isAndroid() const
Tests whether the target is Android.
Definition: Triple.h:725
bool isMIPS64() const
Tests whether the target is MIPS 64-bit (little and big endian).
Definition: Triple.h:871
@ loongarch64
Definition: Triple.h:62
ArchType getArch() const
Get the parsed architecture type of this triple.
Definition: Triple.h:356
EnvironmentType getEnvironment() const
Get the parsed environment type of this triple.
Definition: Triple.h:373
bool isMIPS32() const
Tests whether the target is MIPS 32-bit (little and big endian).
Definition: Triple.h:866
bool isOSWindows() const
Tests whether the OS is Windows.
Definition: Triple.h:584
@ DXContainer
Definition: Triple.h:284
@ UnknownObjectFormat
Definition: Triple.h:281
bool isARM() const
Tests whether the target is ARM (little and big endian).
Definition: Triple.h:789
bool isOSLinux() const
Tests whether the OS is Linux.
Definition: Triple.h:638
bool isAMDGPU() const
Definition: Triple.h:779
bool isMacOSX() const
Is this a Mac OS X triple.
Definition: Triple.h:486
bool isOSFreeBSD() const
Definition: Triple.h:545
bool isOSEmscripten() const
Tests whether the OS is Emscripten.
Definition: Triple.h:658
bool isWatchOS() const
Is this an Apple watchOS triple.
Definition: Triple.h:505
bool isiOS() const
Is this an iOS triple.
Definition: Triple.h:495
bool isPS() const
Tests whether the target is the PS4 or PS5 platform.
Definition: Triple.h:722
bool isOSFuchsia() const
Definition: Triple.h:549
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.
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:304
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
constexpr ScalarTy getFixedValue() const
Definition: TypeSize.h:182
constexpr bool isScalable() const
Returns whether the quantity is scaled by a runtime quantity (vscale).
Definition: TypeSize.h:166
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:119
@ 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:1506
@ 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:1782
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:292
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)
void SplitBlockAndInsertForEachLane(ElementCount EC, Type *IndexTy, Instruction *InsertBefore, std::function< void(IRBuilderBase &, Value *)> Func)
Utility function for performing a given action on each lane of a vector with EC elements.
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:3398
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:1770
#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