LLVM 18.0.0git
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.isLoongArch64();
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 DL = &M.getDataLayout();
660 LongSize = M.getDataLayout().getPointerSizeInBits();
661 IntptrTy = Type::getIntNTy(*C, LongSize);
662 Int8PtrTy = Type::getInt8PtrTy(*C);
664 TargetTriple = Triple(M.getTargetTriple());
665
666 Mapping = getShadowMapping(TargetTriple, LongSize, this->CompileKernel);
667
668 assert(this->UseAfterReturn != AsanDetectStackUseAfterReturnMode::Invalid);
669 }
670
671 TypeSize getAllocaSizeInBytes(const AllocaInst &AI) const {
672 return *AI.getAllocationSize(AI.getModule()->getDataLayout());
673 }
674
675 /// Check if we want (and can) handle this alloca.
676 bool isInterestingAlloca(const AllocaInst &AI);
677
678 bool ignoreAccess(Instruction *Inst, Value *Ptr);
679 void getInterestingMemoryOperands(
681
682 void instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
683 InterestingMemoryOperand &O, bool UseCalls,
684 const DataLayout &DL);
685 void instrumentPointerComparisonOrSubtraction(Instruction *I);
686 void instrumentAddress(Instruction *OrigIns, Instruction *InsertBefore,
687 Value *Addr, MaybeAlign Alignment,
688 uint32_t TypeStoreSize, bool IsWrite,
689 Value *SizeArgument, bool UseCalls, uint32_t Exp);
690 Instruction *instrumentAMDGPUAddress(Instruction *OrigIns,
691 Instruction *InsertBefore, Value *Addr,
692 uint32_t TypeStoreSize, bool IsWrite,
693 Value *SizeArgument);
694 void instrumentUnusualSizeOrAlignment(Instruction *I,
695 Instruction *InsertBefore, Value *Addr,
696 TypeSize TypeStoreSize, bool IsWrite,
697 Value *SizeArgument, bool UseCalls,
698 uint32_t Exp);
699 void instrumentMaskedLoadOrStore(AddressSanitizer *Pass, const DataLayout &DL,
700 Type *IntptrTy, Value *Mask, Value *EVL,
701 Value *Stride, Instruction *I, Value *Addr,
702 MaybeAlign Alignment, unsigned Granularity,
703 Type *OpType, bool IsWrite,
704 Value *SizeArgument, bool UseCalls,
705 uint32_t Exp);
706 Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
707 Value *ShadowValue, uint32_t TypeStoreSize);
708 Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
709 bool IsWrite, size_t AccessSizeIndex,
710 Value *SizeArgument, uint32_t Exp);
711 void instrumentMemIntrinsic(MemIntrinsic *MI);
712 Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
713 bool suppressInstrumentationSiteForDebug(int &Instrumented);
714 bool instrumentFunction(Function &F, const TargetLibraryInfo *TLI);
715 bool maybeInsertAsanInitAtFunctionEntry(Function &F);
716 bool maybeInsertDynamicShadowAtFunctionEntry(Function &F);
717 void markEscapedLocalAllocas(Function &F);
718
719private:
720 friend struct FunctionStackPoisoner;
721
722 void initializeCallbacks(Module &M, const TargetLibraryInfo *TLI);
723
724 bool LooksLikeCodeInBug11395(Instruction *I);
725 bool GlobalIsLinkerInitialized(GlobalVariable *G);
726 bool isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis, Value *Addr,
727 TypeSize TypeStoreSize) const;
728
729 /// Helper to cleanup per-function state.
730 struct FunctionStateRAII {
731 AddressSanitizer *Pass;
732
733 FunctionStateRAII(AddressSanitizer *Pass) : Pass(Pass) {
734 assert(Pass->ProcessedAllocas.empty() &&
735 "last pass forgot to clear cache");
736 assert(!Pass->LocalDynamicShadow);
737 }
738
739 ~FunctionStateRAII() {
740 Pass->LocalDynamicShadow = nullptr;
741 Pass->ProcessedAllocas.clear();
742 }
743 };
744
745 LLVMContext *C;
746 const DataLayout *DL;
747 Triple TargetTriple;
748 int LongSize;
749 bool CompileKernel;
750 bool Recover;
751 bool UseAfterScope;
753 Type *IntptrTy;
754 Type *Int8PtrTy;
755 Type *Int32Ty;
756 ShadowMapping Mapping;
757 FunctionCallee AsanHandleNoReturnFunc;
758 FunctionCallee AsanPtrCmpFunction, AsanPtrSubFunction;
759 Constant *AsanShadowGlobal;
760
761 // These arrays is indexed by AccessIsWrite, Experiment and log2(AccessSize).
762 FunctionCallee AsanErrorCallback[2][2][kNumberOfAccessSizes];
763 FunctionCallee AsanMemoryAccessCallback[2][2][kNumberOfAccessSizes];
764
765 // These arrays is indexed by AccessIsWrite and Experiment.
766 FunctionCallee AsanErrorCallbackSized[2][2];
767 FunctionCallee AsanMemoryAccessCallbackSized[2][2];
768
769 FunctionCallee AsanMemmove, AsanMemcpy, AsanMemset;
770 Value *LocalDynamicShadow = nullptr;
771 const StackSafetyGlobalInfo *SSGI;
772 DenseMap<const AllocaInst *, bool> ProcessedAllocas;
773
774 FunctionCallee AMDGPUAddressShared;
775 FunctionCallee AMDGPUAddressPrivate;
776};
777
778class ModuleAddressSanitizer {
779public:
780 ModuleAddressSanitizer(Module &M, bool CompileKernel = false,
781 bool Recover = false, bool UseGlobalsGC = true,
782 bool UseOdrIndicator = true,
783 AsanDtorKind DestructorKind = AsanDtorKind::Global,
784 AsanCtorKind ConstructorKind = AsanCtorKind::Global)
785 : CompileKernel(ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan
786 : CompileKernel),
787 Recover(ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover),
788 UseGlobalsGC(UseGlobalsGC && ClUseGlobalsGC && !this->CompileKernel),
789 // Enable aliases as they should have no downside with ODR indicators.
790 UsePrivateAlias(ClUsePrivateAlias.getNumOccurrences() > 0
792 : UseOdrIndicator),
793 UseOdrIndicator(ClUseOdrIndicator.getNumOccurrences() > 0
795 : UseOdrIndicator),
796 // Not a typo: ClWithComdat is almost completely pointless without
797 // ClUseGlobalsGC (because then it only works on modules without
798 // globals, which are rare); it is a prerequisite for ClUseGlobalsGC;
799 // and both suffer from gold PR19002 for which UseGlobalsGC constructor
800 // argument is designed as workaround. Therefore, disable both
801 // ClWithComdat and ClUseGlobalsGC unless the frontend says it's ok to
802 // do globals-gc.
803 UseCtorComdat(UseGlobalsGC && ClWithComdat && !this->CompileKernel),
804 DestructorKind(DestructorKind),
805 ConstructorKind(ConstructorKind) {
806 C = &(M.getContext());
807 int LongSize = M.getDataLayout().getPointerSizeInBits();
808 IntptrTy = Type::getIntNTy(*C, LongSize);
809 TargetTriple = Triple(M.getTargetTriple());
810 Mapping = getShadowMapping(TargetTriple, LongSize, this->CompileKernel);
811
812 if (ClOverrideDestructorKind != AsanDtorKind::Invalid)
813 this->DestructorKind = ClOverrideDestructorKind;
814 assert(this->DestructorKind != AsanDtorKind::Invalid);
815 }
816
817 bool instrumentModule(Module &);
818
819private:
820 void initializeCallbacks(Module &M);
821
822 bool InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool *CtorComdat);
823 void InstrumentGlobalsCOFF(IRBuilder<> &IRB, Module &M,
824 ArrayRef<GlobalVariable *> ExtendedGlobals,
825 ArrayRef<Constant *> MetadataInitializers);
826 void InstrumentGlobalsELF(IRBuilder<> &IRB, Module &M,
827 ArrayRef<GlobalVariable *> ExtendedGlobals,
828 ArrayRef<Constant *> MetadataInitializers,
829 const std::string &UniqueModuleId);
830 void InstrumentGlobalsMachO(IRBuilder<> &IRB, Module &M,
831 ArrayRef<GlobalVariable *> ExtendedGlobals,
832 ArrayRef<Constant *> MetadataInitializers);
833 void
834 InstrumentGlobalsWithMetadataArray(IRBuilder<> &IRB, Module &M,
835 ArrayRef<GlobalVariable *> ExtendedGlobals,
836 ArrayRef<Constant *> MetadataInitializers);
837
838 GlobalVariable *CreateMetadataGlobal(Module &M, Constant *Initializer,
839 StringRef OriginalName);
840 void SetComdatForGlobalMetadata(GlobalVariable *G, GlobalVariable *Metadata,
841 StringRef InternalSuffix);
842 Instruction *CreateAsanModuleDtor(Module &M);
843
844 const GlobalVariable *getExcludedAliasedGlobal(const GlobalAlias &GA) const;
845 bool shouldInstrumentGlobal(GlobalVariable *G) const;
846 bool ShouldUseMachOGlobalsSection() const;
847 StringRef getGlobalMetadataSection() const;
848 void poisonOneInitializer(Function &GlobalInit, GlobalValue *ModuleName);
849 void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
850 uint64_t getMinRedzoneSizeForGlobal() const {
851 return getRedzoneSizeForScale(Mapping.Scale);
852 }
853 uint64_t getRedzoneSizeForGlobal(uint64_t SizeInBytes) const;
854 int GetAsanVersion(const Module &M) const;
855
856 bool CompileKernel;
857 bool Recover;
858 bool UseGlobalsGC;
859 bool UsePrivateAlias;
860 bool UseOdrIndicator;
861 bool UseCtorComdat;
862 AsanDtorKind DestructorKind;
863 AsanCtorKind ConstructorKind;
864 Type *IntptrTy;
865 LLVMContext *C;
866 Triple TargetTriple;
867 ShadowMapping Mapping;
868 FunctionCallee AsanPoisonGlobals;
869 FunctionCallee AsanUnpoisonGlobals;
870 FunctionCallee AsanRegisterGlobals;
871 FunctionCallee AsanUnregisterGlobals;
872 FunctionCallee AsanRegisterImageGlobals;
873 FunctionCallee AsanUnregisterImageGlobals;
874 FunctionCallee AsanRegisterElfGlobals;
875 FunctionCallee AsanUnregisterElfGlobals;
876
877 Function *AsanCtorFunction = nullptr;
878 Function *AsanDtorFunction = nullptr;
879};
880
881// Stack poisoning does not play well with exception handling.
882// When an exception is thrown, we essentially bypass the code
883// that unpoisones the stack. This is why the run-time library has
884// to intercept __cxa_throw (as well as longjmp, etc) and unpoison the entire
885// stack in the interceptor. This however does not work inside the
886// actual function which catches the exception. Most likely because the
887// compiler hoists the load of the shadow value somewhere too high.
888// This causes asan to report a non-existing bug on 453.povray.
889// It sounds like an LLVM bug.
890struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
891 Function &F;
892 AddressSanitizer &ASan;
893 DIBuilder DIB;
894 LLVMContext *C;
895 Type *IntptrTy;
896 Type *IntptrPtrTy;
897 ShadowMapping Mapping;
898
900 SmallVector<AllocaInst *, 16> StaticAllocasToMoveUp;
902
903 FunctionCallee AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
904 AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
905 FunctionCallee AsanSetShadowFunc[0x100] = {};
906 FunctionCallee AsanPoisonStackMemoryFunc, AsanUnpoisonStackMemoryFunc;
907 FunctionCallee AsanAllocaPoisonFunc, AsanAllocasUnpoisonFunc;
908
909 // Stores a place and arguments of poisoning/unpoisoning call for alloca.
910 struct AllocaPoisonCall {
911 IntrinsicInst *InsBefore;
912 AllocaInst *AI;
914 bool DoPoison;
915 };
916 SmallVector<AllocaPoisonCall, 8> DynamicAllocaPoisonCallVec;
917 SmallVector<AllocaPoisonCall, 8> StaticAllocaPoisonCallVec;
918 bool HasUntracedLifetimeIntrinsic = false;
919
920 SmallVector<AllocaInst *, 1> DynamicAllocaVec;
921 SmallVector<IntrinsicInst *, 1> StackRestoreVec;
922 AllocaInst *DynamicAllocaLayout = nullptr;
923 IntrinsicInst *LocalEscapeCall = nullptr;
924
925 bool HasInlineAsm = false;
926 bool HasReturnsTwiceCall = false;
927 bool PoisonStack;
928
929 FunctionStackPoisoner(Function &F, AddressSanitizer &ASan)
930 : F(F), ASan(ASan), DIB(*F.getParent(), /*AllowUnresolved*/ false),
931 C(ASan.C), IntptrTy(ASan.IntptrTy),
932 IntptrPtrTy(PointerType::get(IntptrTy, 0)), Mapping(ASan.Mapping),
933 PoisonStack(ClStack &&
934 !Triple(F.getParent()->getTargetTriple()).isAMDGPU()) {}
935
936 bool runOnFunction() {
937 if (!PoisonStack)
938 return false;
939
941 copyArgsPassedByValToAllocas();
942
943 // Collect alloca, ret, lifetime instructions etc.
944 for (BasicBlock *BB : depth_first(&F.getEntryBlock())) visit(*BB);
945
946 if (AllocaVec.empty() && DynamicAllocaVec.empty()) return false;
947
948 initializeCallbacks(*F.getParent());
949
950 if (HasUntracedLifetimeIntrinsic) {
951 // If there are lifetime intrinsics which couldn't be traced back to an
952 // alloca, we may not know exactly when a variable enters scope, and
953 // therefore should "fail safe" by not poisoning them.
954 StaticAllocaPoisonCallVec.clear();
955 DynamicAllocaPoisonCallVec.clear();
956 }
957
958 processDynamicAllocas();
959 processStaticAllocas();
960
961 if (ClDebugStack) {
962 LLVM_DEBUG(dbgs() << F);
963 }
964 return true;
965 }
966
967 // Arguments marked with the "byval" attribute are implicitly copied without
968 // using an alloca instruction. To produce redzones for those arguments, we
969 // copy them a second time into memory allocated with an alloca instruction.
970 void copyArgsPassedByValToAllocas();
971
972 // Finds all Alloca instructions and puts
973 // poisoned red zones around all of them.
974 // Then unpoison everything back before the function returns.
975 void processStaticAllocas();
976 void processDynamicAllocas();
977
978 void createDynamicAllocasInitStorage();
979
980 // ----------------------- Visitors.
981 /// Collect all Ret instructions, or the musttail call instruction if it
982 /// precedes the return instruction.
983 void visitReturnInst(ReturnInst &RI) {
985 RetVec.push_back(CI);
986 else
987 RetVec.push_back(&RI);
988 }
989
990 /// Collect all Resume instructions.
991 void visitResumeInst(ResumeInst &RI) { RetVec.push_back(&RI); }
992
993 /// Collect all CatchReturnInst instructions.
994 void visitCleanupReturnInst(CleanupReturnInst &CRI) { RetVec.push_back(&CRI); }
995
996 void unpoisonDynamicAllocasBeforeInst(Instruction *InstBefore,
997 Value *SavedStack) {
998 IRBuilder<> IRB(InstBefore);
999 Value *DynamicAreaPtr = IRB.CreatePtrToInt(SavedStack, IntptrTy);
1000 // When we insert _asan_allocas_unpoison before @llvm.stackrestore, we
1001 // need to adjust extracted SP to compute the address of the most recent
1002 // alloca. We have a special @llvm.get.dynamic.area.offset intrinsic for
1003 // this purpose.
1004 if (!isa<ReturnInst>(InstBefore)) {
1005 Function *DynamicAreaOffsetFunc = Intrinsic::getDeclaration(
1006 InstBefore->getModule(), Intrinsic::get_dynamic_area_offset,
1007 {IntptrTy});
1008
1009 Value *DynamicAreaOffset = IRB.CreateCall(DynamicAreaOffsetFunc, {});
1010
1011 DynamicAreaPtr = IRB.CreateAdd(IRB.CreatePtrToInt(SavedStack, IntptrTy),
1012 DynamicAreaOffset);
1013 }
1014
1015 IRB.CreateCall(
1016 AsanAllocasUnpoisonFunc,
1017 {IRB.CreateLoad(IntptrTy, DynamicAllocaLayout), DynamicAreaPtr});
1018 }
1019
1020 // Unpoison dynamic allocas redzones.
1021 void unpoisonDynamicAllocas() {
1022 for (Instruction *Ret : RetVec)
1023 unpoisonDynamicAllocasBeforeInst(Ret, DynamicAllocaLayout);
1024
1025 for (Instruction *StackRestoreInst : StackRestoreVec)
1026 unpoisonDynamicAllocasBeforeInst(StackRestoreInst,
1027 StackRestoreInst->getOperand(0));
1028 }
1029
1030 // Deploy and poison redzones around dynamic alloca call. To do this, we
1031 // should replace this call with another one with changed parameters and
1032 // replace all its uses with new address, so
1033 // addr = alloca type, old_size, align
1034 // is replaced by
1035 // new_size = (old_size + additional_size) * sizeof(type)
1036 // tmp = alloca i8, new_size, max(align, 32)
1037 // addr = tmp + 32 (first 32 bytes are for the left redzone).
1038 // Additional_size is added to make new memory allocation contain not only
1039 // requested memory, but also left, partial and right redzones.
1040 void handleDynamicAllocaCall(AllocaInst *AI);
1041
1042 /// Collect Alloca instructions we want (and can) handle.
1043 void visitAllocaInst(AllocaInst &AI) {
1044 // FIXME: Handle scalable vectors instead of ignoring them.
1045 if (!ASan.isInterestingAlloca(AI) ||
1046 isa<ScalableVectorType>(AI.getAllocatedType())) {
1047 if (AI.isStaticAlloca()) {
1048 // Skip over allocas that are present *before* the first instrumented
1049 // alloca, we don't want to move those around.
1050 if (AllocaVec.empty())
1051 return;
1052
1053 StaticAllocasToMoveUp.push_back(&AI);
1054 }
1055 return;
1056 }
1057
1058 if (!AI.isStaticAlloca())
1059 DynamicAllocaVec.push_back(&AI);
1060 else
1061 AllocaVec.push_back(&AI);
1062 }
1063
1064 /// Collect lifetime intrinsic calls to check for use-after-scope
1065 /// errors.
1068 if (ID == Intrinsic::stackrestore) StackRestoreVec.push_back(&II);
1069 if (ID == Intrinsic::localescape) LocalEscapeCall = &II;
1070 if (!ASan.UseAfterScope)
1071 return;
1072 if (!II.isLifetimeStartOrEnd())
1073 return;
1074 // Found lifetime intrinsic, add ASan instrumentation if necessary.
1075 auto *Size = cast<ConstantInt>(II.getArgOperand(0));
1076 // If size argument is undefined, don't do anything.
1077 if (Size->isMinusOne()) return;
1078 // Check that size doesn't saturate uint64_t and can
1079 // be stored in IntptrTy.
1080 const uint64_t SizeValue = Size->getValue().getLimitedValue();
1081 if (SizeValue == ~0ULL ||
1082 !ConstantInt::isValueValidForType(IntptrTy, SizeValue))
1083 return;
1084 // Find alloca instruction that corresponds to llvm.lifetime argument.
1085 // Currently we can only handle lifetime markers pointing to the
1086 // beginning of the alloca.
1087 AllocaInst *AI = findAllocaForValue(II.getArgOperand(1), true);
1088 if (!AI) {
1089 HasUntracedLifetimeIntrinsic = true;
1090 return;
1091 }
1092 // We're interested only in allocas we can handle.
1093 if (!ASan.isInterestingAlloca(*AI))
1094 return;
1095 bool DoPoison = (ID == Intrinsic::lifetime_end);
1096 AllocaPoisonCall APC = {&II, AI, SizeValue, DoPoison};
1097 if (AI->isStaticAlloca())
1098 StaticAllocaPoisonCallVec.push_back(APC);
1100 DynamicAllocaPoisonCallVec.push_back(APC);
1101 }
1102
1103 void visitCallBase(CallBase &CB) {
1104 if (CallInst *CI = dyn_cast<CallInst>(&CB)) {
1105 HasInlineAsm |= CI->isInlineAsm() && &CB != ASan.LocalDynamicShadow;
1106 HasReturnsTwiceCall |= CI->canReturnTwice();
1107 }
1108 }
1109
1110 // ---------------------- Helpers.
1111 void initializeCallbacks(Module &M);
1112
1113 // Copies bytes from ShadowBytes into shadow memory for indexes where
1114 // ShadowMask is not zero. If ShadowMask[i] is zero, we assume that
1115 // ShadowBytes[i] is constantly zero and doesn't need to be overwritten.
1116 void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1117 IRBuilder<> &IRB, Value *ShadowBase);
1118 void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
1119 size_t Begin, size_t End, IRBuilder<> &IRB,
1120 Value *ShadowBase);
1121 void copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
1122 ArrayRef<uint8_t> ShadowBytes, size_t Begin,
1123 size_t End, IRBuilder<> &IRB, Value *ShadowBase);
1124
1125 void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);
1126
1127 Value *createAllocaForLayout(IRBuilder<> &IRB, const ASanStackFrameLayout &L,
1128 bool Dynamic);
1129 PHINode *createPHI(IRBuilder<> &IRB, Value *Cond, Value *ValueIfTrue,
1130 Instruction *ThenTerm, Value *ValueIfFalse);
1131};
1132
1133} // end anonymous namespace
1134
1136 raw_ostream &OS, function_ref<StringRef(StringRef)> MapClassName2PassName) {
1138 OS, MapClassName2PassName);
1139 OS << '<';
1140 if (Options.CompileKernel)
1141 OS << "kernel";
1142 OS << '>';
1143}
1144
1146 const AddressSanitizerOptions &Options, bool UseGlobalGC,
1147 bool UseOdrIndicator, AsanDtorKind DestructorKind,
1148 AsanCtorKind ConstructorKind)
1149 : Options(Options), UseGlobalGC(UseGlobalGC),
1150 UseOdrIndicator(UseOdrIndicator), DestructorKind(DestructorKind),
1151 ConstructorKind(ClConstructorKind) {}
1152
1155 ModuleAddressSanitizer ModuleSanitizer(M, Options.CompileKernel,
1156 Options.Recover, UseGlobalGC,
1157 UseOdrIndicator, DestructorKind,
1158 ConstructorKind);
1159 bool Modified = false;
1160 auto &FAM = MAM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
1161 const StackSafetyGlobalInfo *const SSGI =
1163 for (Function &F : M) {
1164 AddressSanitizer FunctionSanitizer(M, SSGI, Options.CompileKernel,
1165 Options.Recover, Options.UseAfterScope,
1166 Options.UseAfterReturn);
1168 Modified |= FunctionSanitizer.instrumentFunction(F, &TLI);
1169 }
1170 Modified |= ModuleSanitizer.instrumentModule(M);
1171 if (!Modified)
1172 return PreservedAnalyses::all();
1173
1175 // GlobalsAA is considered stateless and does not get invalidated unless
1176 // explicitly invalidated; PreservedAnalyses::none() is not enough. Sanitizers
1177 // make changes that require GlobalsAA to be invalidated.
1178 PA.abandon<GlobalsAA>();
1179 return PA;
1180}
1181
1183 size_t Res = llvm::countr_zero(TypeSize / 8);
1185 return Res;
1186}
1187
1188/// Check if \p G has been created by a trusted compiler pass.
1190 // Do not instrument @llvm.global_ctors, @llvm.used, etc.
1191 if (G->getName().startswith("llvm.") ||
1192 // Do not instrument gcov counter arrays.
1193 G->getName().startswith("__llvm_gcov_ctr") ||
1194 // Do not instrument rtti proxy symbols for function sanitizer.
1195 G->getName().startswith("__llvm_rtti_proxy"))
1196 return true;
1197
1198 // Do not instrument asan globals.
1199 if (G->getName().startswith(kAsanGenPrefix) ||
1200 G->getName().startswith(kSanCovGenPrefix) ||
1201 G->getName().startswith(kODRGenPrefix))
1202 return true;
1203
1204 return false;
1205}
1206
1208 Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
1209 unsigned int AddrSpace = PtrTy->getPointerAddressSpace();
1210 if (AddrSpace == 3 || AddrSpace == 5)
1211 return true;
1212 return false;
1213}
1214
1215Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
1216 // Shadow >> scale
1217 Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
1218 if (Mapping.Offset == 0) return Shadow;
1219 // (Shadow >> scale) | offset
1220 Value *ShadowBase;
1221 if (LocalDynamicShadow)
1222 ShadowBase = LocalDynamicShadow;
1223 else
1224 ShadowBase = ConstantInt::get(IntptrTy, Mapping.Offset);
1225 if (Mapping.OrShadowOffset)
1226 return IRB.CreateOr(Shadow, ShadowBase);
1227 else
1228 return IRB.CreateAdd(Shadow, ShadowBase);
1229}
1230
1231// Instrument memset/memmove/memcpy
1232void AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
1234 if (isa<MemTransferInst>(MI)) {
1235 IRB.CreateCall(
1236 isa<MemMoveInst>(MI) ? AsanMemmove : AsanMemcpy,
1237 {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1238 IRB.CreatePointerCast(MI->getOperand(1), IRB.getInt8PtrTy()),
1239 IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1240 } else if (isa<MemSetInst>(MI)) {
1241 IRB.CreateCall(
1242 AsanMemset,
1243 {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
1244 IRB.CreateIntCast(MI->getOperand(1), IRB.getInt32Ty(), false),
1245 IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
1246 }
1247 MI->eraseFromParent();
1248}
1249
1250/// Check if we want (and can) handle this alloca.
1251bool AddressSanitizer::isInterestingAlloca(const AllocaInst &AI) {
1252 auto PreviouslySeenAllocaInfo = ProcessedAllocas.find(&AI);
1253
1254 if (PreviouslySeenAllocaInfo != ProcessedAllocas.end())
1255 return PreviouslySeenAllocaInfo->getSecond();
1256
1257 bool IsInteresting =
1258 (AI.getAllocatedType()->isSized() &&
1259 // alloca() may be called with 0 size, ignore it.
1260 ((!AI.isStaticAlloca()) || !getAllocaSizeInBytes(AI).isZero()) &&
1261 // We are only interested in allocas not promotable to registers.
1262 // Promotable allocas are common under -O0.
1264 // inalloca allocas are not treated as static, and we don't want
1265 // dynamic alloca instrumentation for them as well.
1266 !AI.isUsedWithInAlloca() &&
1267 // swifterror allocas are register promoted by ISel
1268 !AI.isSwiftError() &&
1269 // safe allocas are not interesting
1270 !(SSGI && SSGI->isSafe(AI)));
1271
1272 ProcessedAllocas[&AI] = IsInteresting;
1273 return IsInteresting;
1274}
1275
1276bool AddressSanitizer::ignoreAccess(Instruction *Inst, Value *Ptr) {
1277 // Instrument accesses from different address spaces only for AMDGPU.
1278 Type *PtrTy = cast<PointerType>(Ptr->getType()->getScalarType());
1279 if (PtrTy->getPointerAddressSpace() != 0 &&
1280 !(TargetTriple.isAMDGPU() && !isUnsupportedAMDGPUAddrspace(Ptr)))
1281 return true;
1282
1283 // Ignore swifterror addresses.
1284 // swifterror memory addresses are mem2reg promoted by instruction
1285 // selection. As such they cannot have regular uses like an instrumentation
1286 // function and it makes no sense to track them as memory.
1287 if (Ptr->isSwiftError())
1288 return true;
1289
1290 // Treat memory accesses to promotable allocas as non-interesting since they
1291 // will not cause memory violations. This greatly speeds up the instrumented
1292 // executable at -O0.
1293 if (auto AI = dyn_cast_or_null<AllocaInst>(Ptr))
1294 if (ClSkipPromotableAllocas && !isInterestingAlloca(*AI))
1295 return true;
1296
1297 if (SSGI != nullptr && SSGI->stackAccessIsSafe(*Inst) &&
1299 return true;
1300
1301 return false;
1302}
1303
1304void AddressSanitizer::getInterestingMemoryOperands(
1306 // Do not instrument the load fetching the dynamic shadow address.
1307 if (LocalDynamicShadow == I)
1308 return;
1309
1310 if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
1311 if (!ClInstrumentReads || ignoreAccess(I, LI->getPointerOperand()))
1312 return;
1313 Interesting.emplace_back(I, LI->getPointerOperandIndex(), false,
1314 LI->getType(), LI->getAlign());
1315 } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
1316 if (!ClInstrumentWrites || ignoreAccess(I, SI->getPointerOperand()))
1317 return;
1318 Interesting.emplace_back(I, SI->getPointerOperandIndex(), true,
1319 SI->getValueOperand()->getType(), SI->getAlign());
1320 } else if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
1321 if (!ClInstrumentAtomics || ignoreAccess(I, RMW->getPointerOperand()))
1322 return;
1323 Interesting.emplace_back(I, RMW->getPointerOperandIndex(), true,
1324 RMW->getValOperand()->getType(), std::nullopt);
1325 } else if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
1326 if (!ClInstrumentAtomics || ignoreAccess(I, XCHG->getPointerOperand()))
1327 return;
1328 Interesting.emplace_back(I, XCHG->getPointerOperandIndex(), true,
1329 XCHG->getCompareOperand()->getType(),
1330 std::nullopt);
1331 } else if (auto CI = dyn_cast<CallInst>(I)) {
1332 switch (CI->getIntrinsicID()) {
1333 case Intrinsic::masked_load:
1334 case Intrinsic::masked_store:
1335 case Intrinsic::masked_gather:
1336 case Intrinsic::masked_scatter: {
1337 bool IsWrite = CI->getType()->isVoidTy();
1338 // Masked store has an initial operand for the value.
1339 unsigned OpOffset = IsWrite ? 1 : 0;
1340 if (IsWrite ? !ClInstrumentWrites : !ClInstrumentReads)
1341 return;
1342
1343 auto BasePtr = CI->getOperand(OpOffset);
1344 if (ignoreAccess(I, BasePtr))
1345 return;
1346 Type *Ty = IsWrite ? CI->getArgOperand(0)->getType() : CI->getType();
1347 MaybeAlign Alignment = Align(1);
1348 // Otherwise no alignment guarantees. We probably got Undef.
1349 if (auto *Op = dyn_cast<ConstantInt>(CI->getOperand(1 + OpOffset)))
1350 Alignment = Op->getMaybeAlignValue();
1351 Value *Mask = CI->getOperand(2 + OpOffset);
1352 Interesting.emplace_back(I, OpOffset, IsWrite, Ty, Alignment, Mask);
1353 break;
1354 }
1355 case Intrinsic::masked_expandload:
1356 case Intrinsic::masked_compressstore: {
1357 bool IsWrite = CI->getIntrinsicID() == Intrinsic::masked_compressstore;
1358 unsigned OpOffset = IsWrite ? 1 : 0;
1359 if (IsWrite ? !ClInstrumentWrites : !ClInstrumentReads)
1360 return;
1361 auto BasePtr = CI->getOperand(OpOffset);
1362 if (ignoreAccess(I, BasePtr))
1363 return;
1364 MaybeAlign Alignment = BasePtr->getPointerAlignment(*DL);
1365 Type *Ty = IsWrite ? CI->getArgOperand(0)->getType() : CI->getType();
1366
1367 IRBuilder IB(I);
1368 Value *Mask = CI->getOperand(1 + OpOffset);
1369 // Use the popcount of Mask as the effective vector length.
1370 Type *ExtTy = VectorType::get(IntptrTy, cast<VectorType>(Ty));
1371 Value *ExtMask = IB.CreateZExt(Mask, ExtTy);
1372 Value *EVL = IB.CreateAddReduce(ExtMask);
1373 Value *TrueMask = ConstantInt::get(Mask->getType(), 1);
1374 Interesting.emplace_back(I, OpOffset, IsWrite, Ty, Alignment, TrueMask,
1375 EVL);
1376 break;
1377 }
1378 case Intrinsic::vp_load:
1379 case Intrinsic::vp_store:
1380 case Intrinsic::experimental_vp_strided_load:
1381 case Intrinsic::experimental_vp_strided_store: {
1382 auto *VPI = cast<VPIntrinsic>(CI);
1383 unsigned IID = CI->getIntrinsicID();
1384 bool IsWrite = CI->getType()->isVoidTy();
1385 if (IsWrite ? !ClInstrumentWrites : !ClInstrumentReads)
1386 return;
1387 unsigned PtrOpNo = *VPI->getMemoryPointerParamPos(IID);
1388 Type *Ty = IsWrite ? CI->getArgOperand(0)->getType() : CI->getType();
1389 MaybeAlign Alignment = VPI->getOperand(PtrOpNo)->getPointerAlignment(*DL);
1390 Value *Stride = nullptr;
1391 if (IID == Intrinsic::experimental_vp_strided_store ||
1392 IID == Intrinsic::experimental_vp_strided_load) {
1393 Stride = VPI->getOperand(PtrOpNo + 1);
1394 // Use the pointer alignment as the element alignment if the stride is a
1395 // mutiple of the pointer alignment. Otherwise, the element alignment
1396 // should be Align(1).
1397 unsigned PointerAlign = Alignment.valueOrOne().value();
1398 if (!isa<ConstantInt>(Stride) ||
1399 cast<ConstantInt>(Stride)->getZExtValue() % PointerAlign != 0)
1400 Alignment = Align(1);
1401 }
1402 Interesting.emplace_back(I, PtrOpNo, IsWrite, Ty, Alignment,
1403 VPI->getMaskParam(), VPI->getVectorLengthParam(),
1404 Stride);
1405 break;
1406 }
1407 case Intrinsic::vp_gather:
1408 case Intrinsic::vp_scatter: {
1409 auto *VPI = cast<VPIntrinsic>(CI);
1410 unsigned IID = CI->getIntrinsicID();
1411 bool IsWrite = IID == Intrinsic::vp_scatter;
1412 if (IsWrite ? !ClInstrumentWrites : !ClInstrumentReads)
1413 return;
1414 unsigned PtrOpNo = *VPI->getMemoryPointerParamPos(IID);
1415 Type *Ty = IsWrite ? CI->getArgOperand(0)->getType() : CI->getType();
1416 MaybeAlign Alignment = VPI->getPointerAlignment();
1417 Interesting.emplace_back(I, PtrOpNo, IsWrite, Ty, Alignment,
1418 VPI->getMaskParam(),
1419 VPI->getVectorLengthParam());
1420 break;
1421 }
1422 default:
1423 for (unsigned ArgNo = 0; ArgNo < CI->arg_size(); ArgNo++) {
1424 if (!ClInstrumentByval || !CI->isByValArgument(ArgNo) ||
1425 ignoreAccess(I, CI->getArgOperand(ArgNo)))
1426 continue;
1427 Type *Ty = CI->getParamByValType(ArgNo);
1428 Interesting.emplace_back(I, ArgNo, false, Ty, Align(1));
1429 }
1430 }
1431 }
1432}
1433
1434static bool isPointerOperand(Value *V) {
1435 return V->getType()->isPointerTy() || isa<PtrToIntInst>(V);
1436}
1437
1438// This is a rough heuristic; it may cause both false positives and
1439// false negatives. The proper implementation requires cooperation with
1440// the frontend.
1442 if (ICmpInst *Cmp = dyn_cast<ICmpInst>(I)) {
1443 if (!Cmp->isRelational())
1444 return false;
1445 } else {
1446 return false;
1447 }
1448 return isPointerOperand(I->getOperand(0)) &&
1449 isPointerOperand(I->getOperand(1));
1450}
1451
1452// This is a rough heuristic; it may cause both false positives and
1453// false negatives. The proper implementation requires cooperation with
1454// the frontend.
1456 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(I)) {
1457 if (BO->getOpcode() != Instruction::Sub)
1458 return false;
1459 } else {
1460 return false;
1461 }
1462 return isPointerOperand(I->getOperand(0)) &&
1463 isPointerOperand(I->getOperand(1));
1464}
1465
1466bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
1467 // If a global variable does not have dynamic initialization we don't
1468 // have to instrument it. However, if a global does not have initializer
1469 // at all, we assume it has dynamic initializer (in other TU).
1470 if (!G->hasInitializer())
1471 return false;
1472
1473 if (G->hasSanitizerMetadata() && G->getSanitizerMetadata().IsDynInit)
1474 return false;
1475
1476 return true;
1477}
1478
1479void AddressSanitizer::instrumentPointerComparisonOrSubtraction(
1480 Instruction *I) {
1481 IRBuilder<> IRB(I);
1482 FunctionCallee F = isa<ICmpInst>(I) ? AsanPtrCmpFunction : AsanPtrSubFunction;
1483 Value *Param[2] = {I->getOperand(0), I->getOperand(1)};
1484 for (Value *&i : Param) {
1485 if (i->getType()->isPointerTy())
1486 i = IRB.CreatePointerCast(i, IntptrTy);
1487 }
1488 IRB.CreateCall(F, Param);
1489}
1490
1491static void doInstrumentAddress(AddressSanitizer *Pass, Instruction *I,
1492 Instruction *InsertBefore, Value *Addr,
1493 MaybeAlign Alignment, unsigned Granularity,
1494 TypeSize TypeStoreSize, bool IsWrite,
1495 Value *SizeArgument, bool UseCalls,
1496 uint32_t Exp) {
1497 // Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check
1498 // if the data is properly aligned.
1499 if (!TypeStoreSize.isScalable()) {
1500 const auto FixedSize = TypeStoreSize.getFixedValue();
1501 switch (FixedSize) {
1502 case 8:
1503 case 16:
1504 case 32:
1505 case 64:
1506 case 128:
1507 if (!Alignment || *Alignment >= Granularity ||
1508 *Alignment >= FixedSize / 8)
1509 return Pass->instrumentAddress(I, InsertBefore, Addr, Alignment,
1510 FixedSize, IsWrite, nullptr, UseCalls,
1511 Exp);
1512 }
1513 }
1514 Pass->instrumentUnusualSizeOrAlignment(I, InsertBefore, Addr, TypeStoreSize,
1515 IsWrite, nullptr, UseCalls, Exp);
1516}
1517
1518void AddressSanitizer::instrumentMaskedLoadOrStore(
1519 AddressSanitizer *Pass, const DataLayout &DL, Type *IntptrTy, Value *Mask,
1520 Value *EVL, Value *Stride, Instruction *I, Value *Addr,
1521 MaybeAlign Alignment, unsigned Granularity, Type *OpType, bool IsWrite,
1522 Value *SizeArgument, bool UseCalls, uint32_t Exp) {
1523 auto *VTy = cast<VectorType>(OpType);
1524 TypeSize ElemTypeSize = DL.getTypeStoreSizeInBits(VTy->getScalarType());
1525 auto Zero = ConstantInt::get(IntptrTy, 0);
1526
1527 IRBuilder IB(I);
1528 Instruction *LoopInsertBefore = I;
1529 if (EVL) {
1530 // The end argument of SplitBlockAndInsertForLane is assumed bigger
1531 // than zero, so we should check whether EVL is zero here.
1532 Type *EVLType = EVL->getType();
1533 Value *IsEVLZero = IB.CreateICmpNE(EVL, ConstantInt::get(EVLType, 0));
1534 LoopInsertBefore = SplitBlockAndInsertIfThen(IsEVLZero, I, false);
1535 IB.SetInsertPoint(LoopInsertBefore);
1536 // Cast EVL to IntptrTy.
1537 EVL = IB.CreateZExtOrTrunc(EVL, IntptrTy);
1538 // To avoid undefined behavior for extracting with out of range index, use
1539 // the minimum of evl and element count as trip count.
1540 Value *EC = IB.CreateElementCount(IntptrTy, VTy->getElementCount());
1541 EVL = IB.CreateBinaryIntrinsic(Intrinsic::umin, EVL, EC);
1542 } else {
1543 EVL = IB.CreateElementCount(IntptrTy, VTy->getElementCount());
1544 }
1545
1546 // Cast Stride to IntptrTy.
1547 if (Stride)
1548 Stride = IB.CreateZExtOrTrunc(Stride, IntptrTy);
1549
1550 SplitBlockAndInsertForEachLane(EVL, LoopInsertBefore,
1551 [&](IRBuilderBase &IRB, Value *Index) {
1552 Value *MaskElem = IRB.CreateExtractElement(Mask, Index);
1553 if (auto *MaskElemC = dyn_cast<ConstantInt>(MaskElem)) {
1554 if (MaskElemC->isZero())
1555 // No check
1556 return;
1557 // Unconditional check
1558 } else {
1559 // Conditional check
1561 MaskElem, &*IRB.GetInsertPoint(), false);
1562 IRB.SetInsertPoint(ThenTerm);
1563 }
1564
1565 Value *InstrumentedAddress;
1566 if (isa<VectorType>(Addr->getType())) {
1567 assert(
1568 cast<VectorType>(Addr->getType())->getElementType()->isPointerTy() &&
1569 "Expected vector of pointer.");
1570 InstrumentedAddress = IRB.CreateExtractElement(Addr, Index);
1571 } else if (Stride) {
1572 Index = IRB.CreateMul(Index, Stride);
1574 InstrumentedAddress = IRB.CreateGEP(Type::getInt8Ty(*C), Addr, {Index});
1575 } else {
1576 InstrumentedAddress = IRB.CreateGEP(VTy, Addr, {Zero, Index});
1577 }
1579 InstrumentedAddress, Alignment, Granularity,
1580 ElemTypeSize, IsWrite, SizeArgument, UseCalls, Exp);
1581 });
1582}
1583
1584void AddressSanitizer::instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
1585 InterestingMemoryOperand &O, bool UseCalls,
1586 const DataLayout &DL) {
1587 Value *Addr = O.getPtr();
1588
1589 // Optimization experiments.
1590 // The experiments can be used to evaluate potential optimizations that remove
1591 // instrumentation (assess false negatives). Instead of completely removing
1592 // some instrumentation, you set Exp to a non-zero value (mask of optimization
1593 // experiments that want to remove instrumentation of this instruction).
1594 // If Exp is non-zero, this pass will emit special calls into runtime
1595 // (e.g. __asan_report_exp_load1 instead of __asan_report_load1). These calls
1596 // make runtime terminate the program in a special way (with a different
1597 // exit status). Then you run the new compiler on a buggy corpus, collect
1598 // the special terminations (ideally, you don't see them at all -- no false
1599 // negatives) and make the decision on the optimization.
1601
1602 if (ClOpt && ClOptGlobals) {
1603 // If initialization order checking is disabled, a simple access to a
1604 // dynamically initialized global is always valid.
1605 GlobalVariable *G = dyn_cast<GlobalVariable>(getUnderlyingObject(Addr));
1606 if (G && (!ClInitializers || GlobalIsLinkerInitialized(G)) &&
1607 isSafeAccess(ObjSizeVis, Addr, O.TypeStoreSize)) {
1608 NumOptimizedAccessesToGlobalVar++;
1609 return;
1610 }
1611 }
1612
1613 if (ClOpt && ClOptStack) {
1614 // A direct inbounds access to a stack variable is always valid.
1615 if (isa<AllocaInst>(getUnderlyingObject(Addr)) &&
1616 isSafeAccess(ObjSizeVis, Addr, O.TypeStoreSize)) {
1617 NumOptimizedAccessesToStackVar++;
1618 return;
1619 }
1620 }
1621
1622 if (O.IsWrite)
1623 NumInstrumentedWrites++;
1624 else
1625 NumInstrumentedReads++;
1626
1627 unsigned Granularity = 1 << Mapping.Scale;
1628 if (O.MaybeMask) {
1629 instrumentMaskedLoadOrStore(this, DL, IntptrTy, O.MaybeMask, O.MaybeEVL,
1630 O.MaybeStride, O.getInsn(), Addr, O.Alignment,
1631 Granularity, O.OpType, O.IsWrite, nullptr,
1632 UseCalls, Exp);
1633 } else {
1634 doInstrumentAddress(this, O.getInsn(), O.getInsn(), Addr, O.Alignment,
1635 Granularity, O.TypeStoreSize, O.IsWrite, nullptr, UseCalls,
1636 Exp);
1637 }
1638}
1639
1640Instruction *AddressSanitizer::generateCrashCode(Instruction *InsertBefore,
1641 Value *Addr, bool IsWrite,
1642 size_t AccessSizeIndex,
1643 Value *SizeArgument,
1644 uint32_t Exp) {
1645 InstrumentationIRBuilder IRB(InsertBefore);
1646 Value *ExpVal = Exp == 0 ? nullptr : ConstantInt::get(IRB.getInt32Ty(), Exp);
1647 CallInst *Call = nullptr;
1648 if (SizeArgument) {
1649 if (Exp == 0)
1650 Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][0],
1651 {Addr, SizeArgument});
1652 else
1653 Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][1],
1654 {Addr, SizeArgument, ExpVal});
1655 } else {
1656 if (Exp == 0)
1657 Call =
1658 IRB.CreateCall(AsanErrorCallback[IsWrite][0][AccessSizeIndex], Addr);
1659 else
1660 Call = IRB.CreateCall(AsanErrorCallback[IsWrite][1][AccessSizeIndex],
1661 {Addr, ExpVal});
1662 }
1663
1664 Call->setCannotMerge();
1665 return Call;
1666}
1667
1668Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
1669 Value *ShadowValue,
1670 uint32_t TypeStoreSize) {
1671 size_t Granularity = static_cast<size_t>(1) << Mapping.Scale;
1672 // Addr & (Granularity - 1)
1673 Value *LastAccessedByte =
1674 IRB.CreateAnd(AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
1675 // (Addr & (Granularity - 1)) + size - 1
1676 if (TypeStoreSize / 8 > 1)
1677 LastAccessedByte = IRB.CreateAdd(
1678 LastAccessedByte, ConstantInt::get(IntptrTy, TypeStoreSize / 8 - 1));
1679 // (uint8_t) ((Addr & (Granularity-1)) + size - 1)
1680 LastAccessedByte =
1681 IRB.CreateIntCast(LastAccessedByte, ShadowValue->getType(), false);
1682 // ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue
1683 return IRB.CreateICmpSGE(LastAccessedByte, ShadowValue);
1684}
1685
1686Instruction *AddressSanitizer::instrumentAMDGPUAddress(
1687 Instruction *OrigIns, Instruction *InsertBefore, Value *Addr,
1688 uint32_t TypeStoreSize, bool IsWrite, Value *SizeArgument) {
1689 // Do not instrument unsupported addrspaces.
1691 return nullptr;
1692 Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
1693 // Follow host instrumentation for global and constant addresses.
1694 if (PtrTy->getPointerAddressSpace() != 0)
1695 return InsertBefore;
1696 // Instrument generic addresses in supported addressspaces.
1697 IRBuilder<> IRB(InsertBefore);
1698 Value *AddrLong = IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy());
1699 Value *IsShared = IRB.CreateCall(AMDGPUAddressShared, {AddrLong});
1700 Value *IsPrivate = IRB.CreateCall(AMDGPUAddressPrivate, {AddrLong});
1701 Value *IsSharedOrPrivate = IRB.CreateOr(IsShared, IsPrivate);
1702 Value *Cmp = IRB.CreateNot(IsSharedOrPrivate);
1703 Value *AddrSpaceZeroLanding =
1704 SplitBlockAndInsertIfThen(Cmp, InsertBefore, false);
1705 InsertBefore = cast<Instruction>(AddrSpaceZeroLanding);
1706 return InsertBefore;
1707}
1708
1709void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
1710 Instruction *InsertBefore, Value *Addr,
1711 MaybeAlign Alignment,
1712 uint32_t TypeStoreSize, bool IsWrite,
1713 Value *SizeArgument, bool UseCalls,
1714 uint32_t Exp) {
1715 if (TargetTriple.isAMDGPU()) {
1716 InsertBefore = instrumentAMDGPUAddress(OrigIns, InsertBefore, Addr,
1717 TypeStoreSize, IsWrite, SizeArgument);
1718 if (!InsertBefore)
1719 return;
1720 }
1721
1722 InstrumentationIRBuilder IRB(InsertBefore);
1723 size_t AccessSizeIndex = TypeStoreSizeToSizeIndex(TypeStoreSize);
1724 const ASanAccessInfo AccessInfo(IsWrite, CompileKernel, AccessSizeIndex);
1725
1726 if (UseCalls && ClOptimizeCallbacks) {
1727 const ASanAccessInfo AccessInfo(IsWrite, CompileKernel, AccessSizeIndex);
1728 Module *M = IRB.GetInsertBlock()->getParent()->getParent();
1729 IRB.CreateCall(
1730 Intrinsic::getDeclaration(M, Intrinsic::asan_check_memaccess),
1731 {IRB.CreatePointerCast(Addr, Int8PtrTy),
1732 ConstantInt::get(Int32Ty, AccessInfo.Packed)});
1733 return;
1734 }
1735
1736 Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1737 if (UseCalls) {
1738 if (Exp == 0)
1739 IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][0][AccessSizeIndex],
1740 AddrLong);
1741 else
1742 IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][1][AccessSizeIndex],
1743 {AddrLong, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1744 return;
1745 }
1746
1747 Type *ShadowTy =
1748 IntegerType::get(*C, std::max(8U, TypeStoreSize >> Mapping.Scale));
1749 Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
1750 Value *ShadowPtr = memToShadow(AddrLong, IRB);
1751 const uint64_t ShadowAlign =
1752 std::max<uint64_t>(Alignment.valueOrOne().value() >> Mapping.Scale, 1);
1753 Value *ShadowValue = IRB.CreateAlignedLoad(
1754 ShadowTy, IRB.CreateIntToPtr(ShadowPtr, ShadowPtrTy), Align(ShadowAlign));
1755
1756 Value *Cmp = IRB.CreateIsNotNull(ShadowValue);
1757 size_t Granularity = 1ULL << Mapping.Scale;
1758 Instruction *CrashTerm = nullptr;
1759
1760 if (ClAlwaysSlowPath || (TypeStoreSize < 8 * Granularity)) {
1761 // We use branch weights for the slow path check, to indicate that the slow
1762 // path is rarely taken. This seems to be the case for SPEC benchmarks.
1764 Cmp, InsertBefore, false, MDBuilder(*C).createBranchWeights(1, 100000));
1765 assert(cast<BranchInst>(CheckTerm)->isUnconditional());
1766 BasicBlock *NextBB = CheckTerm->getSuccessor(0);
1767 IRB.SetInsertPoint(CheckTerm);
1768 Value *Cmp2 = createSlowPathCmp(IRB, AddrLong, ShadowValue, TypeStoreSize);
1769 if (Recover) {
1770 CrashTerm = SplitBlockAndInsertIfThen(Cmp2, CheckTerm, false);
1771 } else {
1772 BasicBlock *CrashBlock =
1773 BasicBlock::Create(*C, "", NextBB->getParent(), NextBB);
1774 CrashTerm = new UnreachableInst(*C, CrashBlock);
1775 BranchInst *NewTerm = BranchInst::Create(CrashBlock, NextBB, Cmp2);
1776 ReplaceInstWithInst(CheckTerm, NewTerm);
1777 }
1778 } else {
1779 CrashTerm = SplitBlockAndInsertIfThen(Cmp, InsertBefore, !Recover);
1780 }
1781
1782 Instruction *Crash = generateCrashCode(CrashTerm, AddrLong, IsWrite,
1783 AccessSizeIndex, SizeArgument, Exp);
1784 if (OrigIns->getDebugLoc())
1785 Crash->setDebugLoc(OrigIns->getDebugLoc());
1786}
1787
1788// Instrument unusual size or unusual alignment.
1789// We can not do it with a single check, so we do 1-byte check for the first
1790// and the last bytes. We call __asan_report_*_n(addr, real_size) to be able
1791// to report the actual access size.
1792void AddressSanitizer::instrumentUnusualSizeOrAlignment(
1793 Instruction *I, Instruction *InsertBefore, Value *Addr, TypeSize TypeStoreSize,
1794 bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp) {
1795 InstrumentationIRBuilder IRB(InsertBefore);
1796 Value *NumBits = IRB.CreateTypeSize(IntptrTy, TypeStoreSize);
1797 Value *Size = IRB.CreateLShr(NumBits, ConstantInt::get(IntptrTy, 3));
1798
1799 Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
1800 if (UseCalls) {
1801 if (Exp == 0)
1802 IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][0],
1803 {AddrLong, Size});
1804 else
1805 IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][1],
1806 {AddrLong, Size, ConstantInt::get(IRB.getInt32Ty(), Exp)});
1807 } else {
1808 Value *SizeMinusOne = IRB.CreateSub(Size, ConstantInt::get(IntptrTy, 1));
1809 Value *LastByte = IRB.CreateIntToPtr(
1810 IRB.CreateAdd(AddrLong, SizeMinusOne),
1811 Addr->getType());
1812 instrumentAddress(I, InsertBefore, Addr, {}, 8, IsWrite, Size, false, Exp);
1813 instrumentAddress(I, InsertBefore, LastByte, {}, 8, IsWrite, Size, false,
1814 Exp);
1815 }
1816}
1817
1818void ModuleAddressSanitizer::poisonOneInitializer(Function &GlobalInit,
1820 // Set up the arguments to our poison/unpoison functions.
1821 IRBuilder<> IRB(&GlobalInit.front(),
1822 GlobalInit.front().getFirstInsertionPt());
1823
1824 // Add a call to poison all external globals before the given function starts.
1825 Value *ModuleNameAddr = ConstantExpr::getPointerCast(ModuleName, IntptrTy);
1826 IRB.CreateCall(AsanPoisonGlobals, ModuleNameAddr);
1827
1828 // Add calls to unpoison all globals before each return instruction.
1829 for (auto &BB : GlobalInit)
1830 if (ReturnInst *RI = dyn_cast<ReturnInst>(BB.getTerminator()))
1831 CallInst::Create(AsanUnpoisonGlobals, "", RI);
1832}
1833
1834void ModuleAddressSanitizer::createInitializerPoisonCalls(
1836 GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
1837 if (!GV)
1838 return;
1839
1840 ConstantArray *CA = dyn_cast<ConstantArray>(GV->getInitializer());
1841 if (!CA)
1842 return;
1843
1844 for (Use &OP : CA->operands()) {
1845 if (isa<ConstantAggregateZero>(OP)) continue;
1846 ConstantStruct *CS = cast<ConstantStruct>(OP);
1847
1848 // Must have a function or null ptr.
1849 if (Function *F = dyn_cast<Function>(CS->getOperand(1))) {
1850 if (F->getName() == kAsanModuleCtorName) continue;
1851 auto *Priority = cast<ConstantInt>(CS->getOperand(0));
1852 // Don't instrument CTORs that will run before asan.module_ctor.
1853 if (Priority->getLimitedValue() <= GetCtorAndDtorPriority(TargetTriple))
1854 continue;
1855 poisonOneInitializer(*F, ModuleName);
1856 }
1857 }
1858}
1859
1860const GlobalVariable *
1861ModuleAddressSanitizer::getExcludedAliasedGlobal(const GlobalAlias &GA) const {
1862 // In case this function should be expanded to include rules that do not just
1863 // apply when CompileKernel is true, either guard all existing rules with an
1864 // 'if (CompileKernel) { ... }' or be absolutely sure that all these rules
1865 // should also apply to user space.
1866 assert(CompileKernel && "Only expecting to be called when compiling kernel");
1867
1868 const Constant *C = GA.getAliasee();
1869
1870 // When compiling the kernel, globals that are aliased by symbols prefixed
1871 // by "__" are special and cannot be padded with a redzone.
1872 if (GA.getName().startswith("__"))
1873 return dyn_cast<GlobalVariable>(C->stripPointerCastsAndAliases());
1874
1875 return nullptr;
1876}
1877
1878bool ModuleAddressSanitizer::shouldInstrumentGlobal(GlobalVariable *G) const {
1879 Type *Ty = G->getValueType();
1880 LLVM_DEBUG(dbgs() << "GLOBAL: " << *G << "\n");
1881
1882 if (G->hasSanitizerMetadata() && G->getSanitizerMetadata().NoAddress)
1883 return false;
1884 if (!Ty->isSized()) return false;
1885 if (!G->hasInitializer()) return false;
1886 // Globals in address space 1 and 4 are supported for AMDGPU.
1887 if (G->getAddressSpace() &&
1888 !(TargetTriple.isAMDGPU() && !isUnsupportedAMDGPUAddrspace(G)))
1889 return false;
1890 if (GlobalWasGeneratedByCompiler(G)) return false; // Our own globals.
1891 // Two problems with thread-locals:
1892 // - The address of the main thread's copy can't be computed at link-time.
1893 // - Need to poison all copies, not just the main thread's one.
1894 if (G->isThreadLocal()) return false;
1895 // For now, just ignore this Global if the alignment is large.
1896 if (G->getAlign() && *G->getAlign() > getMinRedzoneSizeForGlobal()) return false;
1897
1898 // For non-COFF targets, only instrument globals known to be defined by this
1899 // TU.
1900 // FIXME: We can instrument comdat globals on ELF if we are using the
1901 // GC-friendly metadata scheme.
1902 if (!TargetTriple.isOSBinFormatCOFF()) {
1903 if (!G->hasExactDefinition() || G->hasComdat())
1904 return false;
1905 } else {
1906 // On COFF, don't instrument non-ODR linkages.
1907 if (G->isInterposable())
1908 return false;
1909 }
1910
1911 // If a comdat is present, it must have a selection kind that implies ODR
1912 // semantics: no duplicates, any, or exact match.
1913 if (Comdat *C = G->getComdat()) {
1914 switch (C->getSelectionKind()) {
1915 case Comdat::Any:
1916 case Comdat::ExactMatch:
1918 break;
1919 case Comdat::Largest:
1920 case Comdat::SameSize:
1921 return false;
1922 }
1923 }
1924
1925 if (G->hasSection()) {
1926 // The kernel uses explicit sections for mostly special global variables
1927 // that we should not instrument. E.g. the kernel may rely on their layout
1928 // without redzones, or remove them at link time ("discard.*"), etc.
1929 if (CompileKernel)
1930 return false;
1931
1932 StringRef Section = G->getSection();
1933
1934 // Globals from llvm.metadata aren't emitted, do not instrument them.
1935 if (Section == "llvm.metadata") return false;
1936 // Do not instrument globals from special LLVM sections.
1937 if (Section.contains("__llvm") || Section.contains("__LLVM"))
1938 return false;
1939
1940 // Do not instrument function pointers to initialization and termination
1941 // routines: dynamic linker will not properly handle redzones.
1942 if (Section.startswith(".preinit_array") ||
1943 Section.startswith(".init_array") ||
1944 Section.startswith(".fini_array")) {
1945 return false;
1946 }
1947
1948 // Do not instrument user-defined sections (with names resembling
1949 // valid C identifiers)
1950 if (TargetTriple.isOSBinFormatELF()) {
1951 if (llvm::all_of(Section,
1952 [](char c) { return llvm::isAlnum(c) || c == '_'; }))
1953 return false;
1954 }
1955
1956 // On COFF, if the section name contains '$', it is highly likely that the
1957 // user is using section sorting to create an array of globals similar to
1958 // the way initialization callbacks are registered in .init_array and
1959 // .CRT$XCU. The ATL also registers things in .ATL$__[azm]. Adding redzones
1960 // to such globals is counterproductive, because the intent is that they
1961 // will form an array, and out-of-bounds accesses are expected.
1962 // See https://github.com/google/sanitizers/issues/305
1963 // and http://msdn.microsoft.com/en-US/en-en/library/bb918180(v=vs.120).aspx
1964 if (TargetTriple.isOSBinFormatCOFF() && Section.contains('$')) {
1965 LLVM_DEBUG(dbgs() << "Ignoring global in sorted section (contains '$'): "
1966 << *G << "\n");
1967 return false;
1968 }
1969
1970 if (TargetTriple.isOSBinFormatMachO()) {
1971 StringRef ParsedSegment, ParsedSection;
1972 unsigned TAA = 0, StubSize = 0;
1973 bool TAAParsed;
1975 Section, ParsedSegment, ParsedSection, TAA, TAAParsed, StubSize));
1976
1977 // Ignore the globals from the __OBJC section. The ObjC runtime assumes
1978 // those conform to /usr/lib/objc/runtime.h, so we can't add redzones to
1979 // them.
1980 if (ParsedSegment == "__OBJC" ||
1981 (ParsedSegment == "__DATA" && ParsedSection.startswith("__objc_"))) {
1982 LLVM_DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G << "\n");
1983 return false;
1984 }
1985 // See https://github.com/google/sanitizers/issues/32
1986 // Constant CFString instances are compiled in the following way:
1987 // -- the string buffer is emitted into
1988 // __TEXT,__cstring,cstring_literals
1989 // -- the constant NSConstantString structure referencing that buffer
1990 // is placed into __DATA,__cfstring
1991 // Therefore there's no point in placing redzones into __DATA,__cfstring.
1992 // Moreover, it causes the linker to crash on OS X 10.7
1993 if (ParsedSegment == "__DATA" && ParsedSection == "__cfstring") {
1994 LLVM_DEBUG(dbgs() << "Ignoring CFString: " << *G << "\n");
1995 return false;
1996 }
1997 // The linker merges the contents of cstring_literals and removes the
1998 // trailing zeroes.
1999 if (ParsedSegment == "__TEXT" && (TAA & MachO::S_CSTRING_LITERALS)) {
2000 LLVM_DEBUG(dbgs() << "Ignoring a cstring literal: " << *G << "\n");
2001 return false;
2002 }
2003 }
2004 }
2005
2006 if (CompileKernel) {
2007 // Globals that prefixed by "__" are special and cannot be padded with a
2008 // redzone.
2009 if (G->getName().startswith("__"))
2010 return false;
2011 }
2012
2013 return true;
2014}
2015
2016// On Mach-O platforms, we emit global metadata in a separate section of the
2017// binary in order to allow the linker to properly dead strip. This is only
2018// supported on recent versions of ld64.
2019bool ModuleAddressSanitizer::ShouldUseMachOGlobalsSection() const {
2020 if (!TargetTriple.isOSBinFormatMachO())
2021 return false;
2022
2023 if (TargetTriple.isMacOSX() && !TargetTriple.isMacOSXVersionLT(10, 11))
2024 return true;
2025 if (TargetTriple.isiOS() /* or tvOS */ && !TargetTriple.isOSVersionLT(9))
2026 return true;
2027 if (TargetTriple.isWatchOS() && !TargetTriple.isOSVersionLT(2))
2028 return true;
2029 if (TargetTriple.isDriverKit())
2030 return true;
2031
2032 return false;
2033}
2034
2035StringRef ModuleAddressSanitizer::getGlobalMetadataSection() const {
2036 switch (TargetTriple.getObjectFormat()) {
2037 case Triple::COFF: return ".ASAN$GL";
2038 case Triple::ELF: return "asan_globals";
2039 case Triple::MachO: return "__DATA,__asan_globals,regular";
2040 case Triple::Wasm:
2041 case Triple::GOFF:
2042 case Triple::SPIRV:
2043 case Triple::XCOFF:
2046 "ModuleAddressSanitizer not implemented for object file format");
2048 break;
2049 }
2050 llvm_unreachable("unsupported object format");
2051}
2052
2053void ModuleAddressSanitizer::initializeCallbacks(Module &M) {
2054 IRBuilder<> IRB(*C);
2055
2056 // Declare our poisoning and unpoisoning functions.
2057 AsanPoisonGlobals =
2058 M.getOrInsertFunction(kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy);
2059 AsanUnpoisonGlobals =
2060 M.getOrInsertFunction(kAsanUnpoisonGlobalsName, IRB.getVoidTy());
2061
2062 // Declare functions that register/unregister globals.
2063 AsanRegisterGlobals = M.getOrInsertFunction(
2064 kAsanRegisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);
2065 AsanUnregisterGlobals = M.getOrInsertFunction(
2066 kAsanUnregisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);
2067
2068 // Declare the functions that find globals in a shared object and then invoke
2069 // the (un)register function on them.
2070 AsanRegisterImageGlobals = M.getOrInsertFunction(
2071 kAsanRegisterImageGlobalsName, IRB.getVoidTy(), IntptrTy);
2072 AsanUnregisterImageGlobals = M.getOrInsertFunction(
2074
2075 AsanRegisterElfGlobals =
2076 M.getOrInsertFunction(kAsanRegisterElfGlobalsName, IRB.getVoidTy(),
2077 IntptrTy, IntptrTy, IntptrTy);
2078 AsanUnregisterElfGlobals =
2079 M.getOrInsertFunction(kAsanUnregisterElfGlobalsName, IRB.getVoidTy(),
2080 IntptrTy, IntptrTy, IntptrTy);
2081}
2082
2083// Put the metadata and the instrumented global in the same group. This ensures
2084// that the metadata is discarded if the instrumented global is discarded.
2085void ModuleAddressSanitizer::SetComdatForGlobalMetadata(
2086 GlobalVariable *G, GlobalVariable *Metadata, StringRef InternalSuffix) {
2087 Module &M = *G->getParent();
2088 Comdat *C = G->getComdat();
2089 if (!C) {
2090 if (!G->hasName()) {
2091 // If G is unnamed, it must be internal. Give it an artificial name
2092 // so we can put it in a comdat.
2093 assert(G->hasLocalLinkage());
2094 G->setName(Twine(kAsanGenPrefix) + "_anon_global");
2095 }
2096
2097 if (!InternalSuffix.empty() && G->hasLocalLinkage()) {
2098 std::string Name = std::string(G->getName());
2099 Name += InternalSuffix;
2100 C = M.getOrInsertComdat(Name);
2101 } else {
2102 C = M.getOrInsertComdat(G->getName());
2103 }
2104
2105 // Make this IMAGE_COMDAT_SELECT_NODUPLICATES on COFF. Also upgrade private
2106 // linkage to internal linkage so that a symbol table entry is emitted. This
2107 // is necessary in order to create the comdat group.
2108 if (TargetTriple.isOSBinFormatCOFF()) {
2109 C->setSelectionKind(Comdat::NoDeduplicate);
2110 if (G->hasPrivateLinkage())
2111 G->setLinkage(GlobalValue::InternalLinkage);
2112 }
2113 G->setComdat(C);
2114 }
2115
2116 assert(G->hasComdat());
2117 Metadata->setComdat(G->getComdat());
2118}
2119
2120// Create a separate metadata global and put it in the appropriate ASan
2121// global registration section.
2123ModuleAddressSanitizer::CreateMetadataGlobal(Module &M, Constant *Initializer,
2124 StringRef OriginalName) {
2125 auto Linkage = TargetTriple.isOSBinFormatMachO()
2129 M, Initializer->getType(), false, Linkage, Initializer,
2130 Twine("__asan_global_") + GlobalValue::dropLLVMManglingEscape(OriginalName));
2131 Metadata->setSection(getGlobalMetadataSection());
2132 return Metadata;
2133}
2134
2135Instruction *ModuleAddressSanitizer::CreateAsanModuleDtor(Module &M) {
2136 AsanDtorFunction = Function::createWithDefaultAttr(
2139 AsanDtorFunction->addFnAttr(Attribute::NoUnwind);
2140 // Ensure Dtor cannot be discarded, even if in a comdat.
2141 appendToUsed(M, {AsanDtorFunction});
2142 BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
2143
2144 return ReturnInst::Create(*C, AsanDtorBB);
2145}
2146
2147void ModuleAddressSanitizer::InstrumentGlobalsCOFF(
2148 IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2149 ArrayRef<Constant *> MetadataInitializers) {
2150 assert(ExtendedGlobals.size() == MetadataInitializers.size());
2151 auto &DL = M.getDataLayout();
2152
2153 SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
2154 for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2155 Constant *Initializer = MetadataInitializers[i];
2156 GlobalVariable *G = ExtendedGlobals[i];
2158 CreateMetadataGlobal(M, Initializer, G->getName());
2159 MDNode *MD = MDNode::get(M.getContext(), ValueAsMetadata::get(G));
2160 Metadata->setMetadata(LLVMContext::MD_associated, MD);
2161 MetadataGlobals[i] = Metadata;
2162
2163 // The MSVC linker always inserts padding when linking incrementally. We
2164 // cope with that by aligning each struct to its size, which must be a power
2165 // of two.
2166 unsigned SizeOfGlobalStruct = DL.getTypeAllocSize(Initializer->getType());
2167 assert(isPowerOf2_32(SizeOfGlobalStruct) &&
2168 "global metadata will not be padded appropriately");
2169 Metadata->setAlignment(assumeAligned(SizeOfGlobalStruct));
2170
2171 SetComdatForGlobalMetadata(G, Metadata, "");
2172 }
2173
2174 // Update llvm.compiler.used, adding the new metadata globals. This is
2175 // needed so that during LTO these variables stay alive.
2176 if (!MetadataGlobals.empty())
2177 appendToCompilerUsed(M, MetadataGlobals);
2178}
2179
2180void ModuleAddressSanitizer::InstrumentGlobalsELF(
2181 IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2182 ArrayRef<Constant *> MetadataInitializers,
2183 const std::string &UniqueModuleId) {
2184 assert(ExtendedGlobals.size() == MetadataInitializers.size());
2185
2186 // Putting globals in a comdat changes the semantic and potentially cause
2187 // false negative odr violations at link time. If odr indicators are used, we
2188 // keep the comdat sections, as link time odr violations will be dectected on
2189 // the odr indicator symbols.
2190 bool UseComdatForGlobalsGC = UseOdrIndicator;
2191
2192 SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
2193 for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2194 GlobalVariable *G = ExtendedGlobals[i];
2196 CreateMetadataGlobal(M, MetadataInitializers[i], G->getName());
2197 MDNode *MD = MDNode::get(M.getContext(), ValueAsMetadata::get(G));
2198 Metadata->setMetadata(LLVMContext::MD_associated, MD);
2199 MetadataGlobals[i] = Metadata;
2200
2201 if (UseComdatForGlobalsGC)
2202 SetComdatForGlobalMetadata(G, Metadata, UniqueModuleId);
2203 }
2204
2205 // Update llvm.compiler.used, adding the new metadata globals. This is
2206 // needed so that during LTO these variables stay alive.
2207 if (!MetadataGlobals.empty())
2208 appendToCompilerUsed(M, MetadataGlobals);
2209
2210 // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
2211 // to look up the loaded image that contains it. Second, we can store in it
2212 // whether registration has already occurred, to prevent duplicate
2213 // registration.
2214 //
2215 // Common linkage ensures that there is only one global per shared library.
2216 GlobalVariable *RegisteredFlag = new GlobalVariable(
2217 M, IntptrTy, false, GlobalVariable::CommonLinkage,
2220
2221 // Create start and stop symbols.
2222 GlobalVariable *StartELFMetadata = new GlobalVariable(
2223 M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
2224 "__start_" + getGlobalMetadataSection());
2226 GlobalVariable *StopELFMetadata = new GlobalVariable(
2227 M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
2228 "__stop_" + getGlobalMetadataSection());
2230
2231 // Create a call to register the globals with the runtime.
2232 if (ConstructorKind == AsanCtorKind::Global)
2233 IRB.CreateCall(AsanRegisterElfGlobals,
2234 {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
2235 IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
2236 IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
2237
2238 // We also need to unregister globals at the end, e.g., when a shared library
2239 // gets closed.
2240 if (DestructorKind != AsanDtorKind::None) {
2241 IRBuilder<> IrbDtor(CreateAsanModuleDtor(M));
2242 IrbDtor.CreateCall(AsanUnregisterElfGlobals,
2243 {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
2244 IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
2245 IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
2246 }
2247}
2248
2249void ModuleAddressSanitizer::InstrumentGlobalsMachO(
2250 IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2251 ArrayRef<Constant *> MetadataInitializers) {
2252 assert(ExtendedGlobals.size() == MetadataInitializers.size());
2253
2254 // On recent Mach-O platforms, use a structure which binds the liveness of
2255 // the global variable to the metadata struct. Keep the list of "Liveness" GV
2256 // created to be added to llvm.compiler.used
2257 StructType *LivenessTy = StructType::get(IntptrTy, IntptrTy);
2258 SmallVector<GlobalValue *, 16> LivenessGlobals(ExtendedGlobals.size());
2259
2260 for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
2261 Constant *Initializer = MetadataInitializers[i];
2262 GlobalVariable *G = ExtendedGlobals[i];
2264 CreateMetadataGlobal(M, Initializer, G->getName());
2265
2266 // On recent Mach-O platforms, we emit the global metadata in a way that
2267 // allows the linker to properly strip dead globals.
2268 auto LivenessBinder =
2269 ConstantStruct::get(LivenessTy, Initializer->getAggregateElement(0u),
2271 GlobalVariable *Liveness = new GlobalVariable(
2272 M, LivenessTy, false, GlobalVariable::InternalLinkage, LivenessBinder,
2273 Twine("__asan_binder_") + G->getName());
2274 Liveness->setSection("__DATA,__asan_liveness,regular,live_support");
2275 LivenessGlobals[i] = Liveness;
2276 }
2277
2278 // Update llvm.compiler.used, adding the new liveness globals. This is
2279 // needed so that during LTO these variables stay alive. The alternative
2280 // would be to have the linker handling the LTO symbols, but libLTO
2281 // current API does not expose access to the section for each symbol.
2282 if (!LivenessGlobals.empty())
2283 appendToCompilerUsed(M, LivenessGlobals);
2284
2285 // RegisteredFlag serves two purposes. First, we can pass it to dladdr()
2286 // to look up the loaded image that contains it. Second, we can store in it
2287 // whether registration has already occurred, to prevent duplicate
2288 // registration.
2289 //
2290 // common linkage ensures that there is only one global per shared library.
2291 GlobalVariable *RegisteredFlag = new GlobalVariable(
2292 M, IntptrTy, false, GlobalVariable::CommonLinkage,
2295
2296 if (ConstructorKind == AsanCtorKind::Global)
2297 IRB.CreateCall(AsanRegisterImageGlobals,
2298 {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2299
2300 // We also need to unregister globals at the end, e.g., when a shared library
2301 // gets closed.
2302 if (DestructorKind != AsanDtorKind::None) {
2303 IRBuilder<> IrbDtor(CreateAsanModuleDtor(M));
2304 IrbDtor.CreateCall(AsanUnregisterImageGlobals,
2305 {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
2306 }
2307}
2308
2309void ModuleAddressSanitizer::InstrumentGlobalsWithMetadataArray(
2310 IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
2311 ArrayRef<Constant *> MetadataInitializers) {
2312 assert(ExtendedGlobals.size() == MetadataInitializers.size());
2313 unsigned N = ExtendedGlobals.size();
2314 assert(N > 0);
2315
2316 // On platforms that don't have a custom metadata section, we emit an array
2317 // of global metadata structures.
2318 ArrayType *ArrayOfGlobalStructTy =
2319 ArrayType::get(MetadataInitializers[0]->getType(), N);
2320 auto AllGlobals = new GlobalVariable(
2321 M, ArrayOfGlobalStructTy, false, GlobalVariable::InternalLinkage,
2322 ConstantArray::get(ArrayOfGlobalStructTy, MetadataInitializers), "");
2323 if (Mapping.Scale > 3)
2324 AllGlobals->setAlignment(Align(1ULL << Mapping.Scale));
2325
2326 if (ConstructorKind == AsanCtorKind::Global)
2327 IRB.CreateCall(AsanRegisterGlobals,
2328 {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2329 ConstantInt::get(IntptrTy, N)});
2330
2331 // We also need to unregister globals at the end, e.g., when a shared library
2332 // gets closed.
2333 if (DestructorKind != AsanDtorKind::None) {
2334 IRBuilder<> IrbDtor(CreateAsanModuleDtor(M));
2335 IrbDtor.CreateCall(AsanUnregisterGlobals,
2336 {IRB.CreatePointerCast(AllGlobals, IntptrTy),
2337 ConstantInt::get(IntptrTy, N)});
2338 }
2339}
2340
2341// This function replaces all global variables with new variables that have
2342// trailing redzones. It also creates a function that poisons
2343// redzones and inserts this function into llvm.global_ctors.
2344// Sets *CtorComdat to true if the global registration code emitted into the
2345// asan constructor is comdat-compatible.
2346bool ModuleAddressSanitizer::InstrumentGlobals(IRBuilder<> &IRB, Module &M,
2347 bool *CtorComdat) {
2348 *CtorComdat = false;
2349
2350 // Build set of globals that are aliased by some GA, where
2351 // getExcludedAliasedGlobal(GA) returns the relevant GlobalVariable.
2352 SmallPtrSet<const GlobalVariable *, 16> AliasedGlobalExclusions;
2353 if (CompileKernel) {
2354 for (auto &GA : M.aliases()) {
2355 if (const GlobalVariable *GV = getExcludedAliasedGlobal(GA))
2356 AliasedGlobalExclusions.insert(GV);
2357 }
2358 }
2359
2360 SmallVector<GlobalVariable *, 16> GlobalsToChange;
2361 for (auto &G : M.globals()) {
2362 if (!AliasedGlobalExclusions.count(&G) && shouldInstrumentGlobal(&G))
2363 GlobalsToChange.push_back(&G);
2364 }
2365
2366 size_t n = GlobalsToChange.size();
2367 if (n == 0) {
2368 *CtorComdat = true;
2369 return false;
2370 }
2371
2372 auto &DL = M.getDataLayout();
2373
2374 // A global is described by a structure
2375 // size_t beg;
2376 // size_t size;
2377 // size_t size_with_redzone;
2378 // const char *name;
2379 // const char *module_name;
2380 // size_t has_dynamic_init;
2381 // size_t padding_for_windows_msvc_incremental_link;
2382 // size_t odr_indicator;
2383 // We initialize an array of such structures and pass it to a run-time call.
2384 StructType *GlobalStructTy =
2385 StructType::get(IntptrTy, IntptrTy, IntptrTy, IntptrTy, IntptrTy,
2386 IntptrTy, IntptrTy, IntptrTy);
2388 SmallVector<Constant *, 16> Initializers(n);
2389
2390 bool HasDynamicallyInitializedGlobals = false;
2391
2392 // We shouldn't merge same module names, as this string serves as unique
2393 // module ID in runtime.
2395 M, M.getModuleIdentifier(), /*AllowMerging*/ false, kAsanGenPrefix);
2396
2397 for (size_t i = 0; i < n; i++) {
2398 GlobalVariable *G = GlobalsToChange[i];
2399
2401 if (G->hasSanitizerMetadata())
2402 MD = G->getSanitizerMetadata();
2403
2404 // The runtime library tries demangling symbol names in the descriptor but
2405 // functionality like __cxa_demangle may be unavailable (e.g.
2406 // -static-libstdc++). So we demangle the symbol names here.
2407 std::string NameForGlobal = G->getName().str();
2410 /*AllowMerging*/ true, kAsanGenPrefix);
2411
2412 Type *Ty = G->getValueType();
2413 const uint64_t SizeInBytes = DL.getTypeAllocSize(Ty);
2414 const uint64_t RightRedzoneSize = getRedzoneSizeForGlobal(SizeInBytes);
2415 Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
2416
2417 StructType *NewTy = StructType::get(Ty, RightRedZoneTy);
2418 Constant *NewInitializer = ConstantStruct::get(
2419 NewTy, G->getInitializer(), Constant::getNullValue(RightRedZoneTy));
2420
2421 // Create a new global variable with enough space for a redzone.
2422 GlobalValue::LinkageTypes Linkage = G->getLinkage();
2423 if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage)
2425 GlobalVariable *NewGlobal = new GlobalVariable(
2426 M, NewTy, G->isConstant(), Linkage, NewInitializer, "", G,
2427 G->getThreadLocalMode(), G->getAddressSpace());
2428 NewGlobal->copyAttributesFrom(G);
2429 NewGlobal->setComdat(G->getComdat());
2430 NewGlobal->setAlignment(Align(getMinRedzoneSizeForGlobal()));
2431 // Don't fold globals with redzones. ODR violation detector and redzone
2432 // poisoning implicitly creates a dependence on the global's address, so it
2433 // is no longer valid for it to be marked unnamed_addr.
2435
2436 // Move null-terminated C strings to "__asan_cstring" section on Darwin.
2437 if (TargetTriple.isOSBinFormatMachO() && !G->hasSection() &&
2438 G->isConstant()) {
2439 auto Seq = dyn_cast<ConstantDataSequential>(G->getInitializer());
2440 if (Seq && Seq->isCString())
2441 NewGlobal->setSection("__TEXT,__asan_cstring,regular");
2442 }
2443
2444 // Transfer the debug info and type metadata. The payload starts at offset
2445 // zero so we can copy the metadata over as is.
2446 NewGlobal->copyMetadata(G, 0);
2447
2448 Value *Indices2[2];
2449 Indices2[0] = IRB.getInt32(0);
2450 Indices2[1] = IRB.getInt32(0);
2451
2452 G->replaceAllUsesWith(
2453 ConstantExpr::getGetElementPtr(NewTy, NewGlobal, Indices2, true));
2454 NewGlobal->takeName(G);
2455 G->eraseFromParent();
2456 NewGlobals[i] = NewGlobal;
2457
2458 Constant *ODRIndicator = ConstantExpr::getNullValue(IRB.getInt8PtrTy());
2459 GlobalValue *InstrumentedGlobal = NewGlobal;
2460
2461 bool CanUsePrivateAliases =
2462 TargetTriple.isOSBinFormatELF() || TargetTriple.isOSBinFormatMachO() ||
2463 TargetTriple.isOSBinFormatWasm();
2464 if (CanUsePrivateAliases && UsePrivateAlias) {
2465 // Create local alias for NewGlobal to avoid crash on ODR between
2466 // instrumented and non-instrumented libraries.
2467 InstrumentedGlobal =
2469 }
2470
2471 // ODR should not happen for local linkage.
2472 if (NewGlobal->hasLocalLinkage()) {
2473 ODRIndicator = ConstantExpr::getIntToPtr(ConstantInt::get(IntptrTy, -1),
2474 IRB.getInt8PtrTy());
2475 } else if (UseOdrIndicator) {
2476 // With local aliases, we need to provide another externally visible
2477 // symbol __odr_asan_XXX to detect ODR violation.
2478 auto *ODRIndicatorSym =
2479 new GlobalVariable(M, IRB.getInt8Ty(), false, Linkage,
2481 kODRGenPrefix + NameForGlobal, nullptr,
2482 NewGlobal->getThreadLocalMode());
2483
2484 // Set meaningful attributes for indicator symbol.
2485 ODRIndicatorSym->setVisibility(NewGlobal->getVisibility());
2486 ODRIndicatorSym->setDLLStorageClass(NewGlobal->getDLLStorageClass());
2487 ODRIndicatorSym->setAlignment(Align(1));
2488 ODRIndicator = ODRIndicatorSym;
2489 }
2490
2491 Constant *Initializer = ConstantStruct::get(
2492 GlobalStructTy,
2493 ConstantExpr::getPointerCast(InstrumentedGlobal, IntptrTy),
2494 ConstantInt::get(IntptrTy, SizeInBytes),
2495 ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
2498 ConstantInt::get(IntptrTy, MD.IsDynInit),
2499 Constant::getNullValue(IntptrTy),
2500 ConstantExpr::getPointerCast(ODRIndicator, IntptrTy));
2501
2502 if (ClInitializers && MD.IsDynInit)
2503 HasDynamicallyInitializedGlobals = true;
2504
2505 LLVM_DEBUG(dbgs() << "NEW GLOBAL: " << *NewGlobal << "\n");
2506
2507 Initializers[i] = Initializer;
2508 }
2509
2510 // Add instrumented globals to llvm.compiler.used list to avoid LTO from
2511 // ConstantMerge'ing them.
2512 SmallVector<GlobalValue *, 16> GlobalsToAddToUsedList;
2513 for (size_t i = 0; i < n; i++) {
2514 GlobalVariable *G = NewGlobals[i];
2515 if (G->getName().empty()) continue;
2516 GlobalsToAddToUsedList.push_back(G);
2517 }
2518 appendToCompilerUsed(M, ArrayRef<GlobalValue *>(GlobalsToAddToUsedList));
2519
2520 std::string ELFUniqueModuleId =
2521 (UseGlobalsGC && TargetTriple.isOSBinFormatELF()) ? getUniqueModuleId(&M)
2522 : "";
2523
2524 if (!ELFUniqueModuleId.empty()) {
2525 InstrumentGlobalsELF(IRB, M, NewGlobals, Initializers, ELFUniqueModuleId);
2526 *CtorComdat = true;
2527 } else if (UseGlobalsGC && TargetTriple.isOSBinFormatCOFF()) {
2528 InstrumentGlobalsCOFF(IRB, M, NewGlobals, Initializers);
2529 } else if (UseGlobalsGC && ShouldUseMachOGlobalsSection()) {
2530 InstrumentGlobalsMachO(IRB, M, NewGlobals, Initializers);
2531 } else {
2532 InstrumentGlobalsWithMetadataArray(IRB, M, NewGlobals, Initializers);
2533 }
2534
2535 // Create calls for poisoning before initializers run and unpoisoning after.
2536 if (HasDynamicallyInitializedGlobals)
2537 createInitializerPoisonCalls(M, ModuleName);
2538
2539 LLVM_DEBUG(dbgs() << M);
2540 return true;
2541}
2542
2544ModuleAddressSanitizer::getRedzoneSizeForGlobal(uint64_t SizeInBytes) const {
2545 constexpr uint64_t kMaxRZ = 1 << 18;
2546 const uint64_t MinRZ = getMinRedzoneSizeForGlobal();
2547
2548 uint64_t RZ = 0;
2549 if (SizeInBytes <= MinRZ / 2) {
2550 // Reduce redzone size for small size objects, e.g. int, char[1]. MinRZ is
2551 // at least 32 bytes, optimize when SizeInBytes is less than or equal to
2552 // half of MinRZ.
2553 RZ = MinRZ - SizeInBytes;
2554 } else {
2555 // Calculate RZ, where MinRZ <= RZ <= MaxRZ, and RZ ~ 1/4 * SizeInBytes.
2556 RZ = std::clamp((SizeInBytes / MinRZ / 4) * MinRZ, MinRZ, kMaxRZ);
2557
2558 // Round up to multiple of MinRZ.
2559 if (SizeInBytes % MinRZ)
2560 RZ += MinRZ - (SizeInBytes % MinRZ);
2561 }
2562
2563 assert((RZ + SizeInBytes) % MinRZ == 0);
2564
2565 return RZ;
2566}
2567
2568int ModuleAddressSanitizer::GetAsanVersion(const Module &M) const {
2569 int LongSize = M.getDataLayout().getPointerSizeInBits();
2570 bool isAndroid = Triple(M.getTargetTriple()).isAndroid();
2571 int Version = 8;
2572 // 32-bit Android is one version ahead because of the switch to dynamic
2573 // shadow.
2574 Version += (LongSize == 32 && isAndroid);
2575 return Version;
2576}
2577
2578bool ModuleAddressSanitizer::instrumentModule(Module &M) {
2579 initializeCallbacks(M);
2580
2581 // Create a module constructor. A destructor is created lazily because not all
2582 // platforms, and not all modules need it.
2583 if (ConstructorKind == AsanCtorKind::Global) {
2584 if (CompileKernel) {
2585 // The kernel always builds with its own runtime, and therefore does not
2586 // need the init and version check calls.
2587 AsanCtorFunction = createSanitizerCtor(M, kAsanModuleCtorName);
2588 } else {
2589 std::string AsanVersion = std::to_string(GetAsanVersion(M));
2590 std::string VersionCheckName =
2592 std::tie(AsanCtorFunction, std::ignore) =
2594 kAsanInitName, /*InitArgTypes=*/{},
2595 /*InitArgs=*/{}, VersionCheckName);
2596 }
2597 }
2598
2599 bool CtorComdat = true;
2600 if (ClGlobals) {
2601 assert(AsanCtorFunction || ConstructorKind == AsanCtorKind::None);
2602 if (AsanCtorFunction) {
2603 IRBuilder<> IRB(AsanCtorFunction->getEntryBlock().getTerminator());
2604 InstrumentGlobals(IRB, M, &CtorComdat);
2605 } else {
2606 IRBuilder<> IRB(*C);
2607 InstrumentGlobals(IRB, M, &CtorComdat);
2608 }
2609 }
2610
2611 const uint64_t Priority = GetCtorAndDtorPriority(TargetTriple);
2612
2613 // Put the constructor and destructor in comdat if both
2614 // (1) global instrumentation is not TU-specific
2615 // (2) target is ELF.
2616 if (UseCtorComdat && TargetTriple.isOSBinFormatELF() && CtorComdat) {
2617 if (AsanCtorFunction) {
2618 AsanCtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleCtorName));
2619 appendToGlobalCtors(M, AsanCtorFunction, Priority, AsanCtorFunction);
2620 }
2621 if (AsanDtorFunction) {
2622 AsanDtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleDtorName));
2623 appendToGlobalDtors(M, AsanDtorFunction, Priority, AsanDtorFunction);
2624 }
2625 } else {
2626 if (AsanCtorFunction)
2627 appendToGlobalCtors(M, AsanCtorFunction, Priority);
2628 if (AsanDtorFunction)
2629 appendToGlobalDtors(M, AsanDtorFunction, Priority);
2630 }
2631
2632 return true;
2633}
2634
2635void AddressSanitizer::initializeCallbacks(Module &M, const TargetLibraryInfo *TLI) {
2636 IRBuilder<> IRB(*C);
2637 // Create __asan_report* callbacks.
2638 // IsWrite, TypeSize and Exp are encoded in the function name.
2639 for (int Exp = 0; Exp < 2; Exp++) {
2640 for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
2641 const std::string TypeStr = AccessIsWrite ? "store" : "load";
2642 const std::string ExpStr = Exp ? "exp_" : "";
2643 const std::string EndingStr = Recover ? "_noabort" : "";
2644
2645 SmallVector<Type *, 3> Args2 = {IntptrTy, IntptrTy};
2646 SmallVector<Type *, 2> Args1{1, IntptrTy};
2647 AttributeList AL2;
2648 AttributeList AL1;
2649 if (Exp) {
2650 Type *ExpType = Type::getInt32Ty(*C);
2651 Args2.push_back(ExpType);
2652 Args1.push_back(ExpType);
2653 if (auto AK = TLI->getExtAttrForI32Param(false)) {
2654 AL2 = AL2.addParamAttribute(*C, 2, AK);
2655 AL1 = AL1.addParamAttribute(*C, 1, AK);
2656 }
2657 }
2658 AsanErrorCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
2659 kAsanReportErrorTemplate + ExpStr + TypeStr + "_n" + EndingStr,
2660 FunctionType::get(IRB.getVoidTy(), Args2, false), AL2);
2661
2662 AsanMemoryAccessCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
2663 ClMemoryAccessCallbackPrefix + ExpStr + TypeStr + "N" + EndingStr,
2664 FunctionType::get(IRB.getVoidTy(), Args2, false), AL2);
2665
2666 for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
2667 AccessSizeIndex++) {
2668 const std::string Suffix = TypeStr + itostr(1ULL << AccessSizeIndex);
2669 AsanErrorCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2670 M.getOrInsertFunction(
2671 kAsanReportErrorTemplate + ExpStr + Suffix + EndingStr,
2672 FunctionType::get(IRB.getVoidTy(), Args1, false), AL1);
2673
2674 AsanMemoryAccessCallback[AccessIsWrite][Exp][AccessSizeIndex] =
2675 M.getOrInsertFunction(
2676 ClMemoryAccessCallbackPrefix + ExpStr + Suffix + EndingStr,
2677 FunctionType::get(IRB.getVoidTy(), Args1, false), AL1);
2678 }
2679 }
2680 }
2681
2682 const std::string MemIntrinCallbackPrefix =
2683 (CompileKernel && !ClKasanMemIntrinCallbackPrefix)
2684 ? std::string("")
2686 AsanMemmove = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memmove",
2687 IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2688 IRB.getInt8PtrTy(), IntptrTy);
2689 AsanMemcpy = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memcpy",
2690 IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2691 IRB.getInt8PtrTy(), IntptrTy);
2692 AsanMemset = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memset",
2693 TLI->getAttrList(C, {1}, /*Signed=*/false),
2694 IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
2695 IRB.getInt32Ty(), IntptrTy);
2696
2697 AsanHandleNoReturnFunc =
2698 M.getOrInsertFunction(kAsanHandleNoReturnName, IRB.getVoidTy());
2699
2700 AsanPtrCmpFunction =
2701 M.getOrInsertFunction(kAsanPtrCmp, IRB.getVoidTy(), IntptrTy, IntptrTy);
2702 AsanPtrSubFunction =
2703 M.getOrInsertFunction(kAsanPtrSub, IRB.getVoidTy(), IntptrTy, IntptrTy);
2704 if (Mapping.InGlobal)
2705 AsanShadowGlobal = M.getOrInsertGlobal("__asan_shadow",
2706 ArrayType::get(IRB.getInt8Ty(), 0));
2707
2708 AMDGPUAddressShared = M.getOrInsertFunction(
2710 AMDGPUAddressPrivate = M.getOrInsertFunction(
2712}
2713
2714bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
2715 // For each NSObject descendant having a +load method, this method is invoked
2716 // by the ObjC runtime before any of the static constructors is called.
2717 // Therefore we need to instrument such methods with a call to __asan_init
2718 // at the beginning in order to initialize our runtime before any access to
2719 // the shadow memory.
2720 // We cannot just ignore these methods, because they may call other
2721 // instrumented functions.
2722 if (F.getName().find(" load]") != std::string::npos) {
2723 FunctionCallee AsanInitFunction =
2724 declareSanitizerInitFunction(*F.getParent(), kAsanInitName, {});
2725 IRBuilder<> IRB(&F.front(), F.front().begin());
2726 IRB.CreateCall(AsanInitFunction, {});
2727 return true;
2728 }
2729 return false;
2730}
2731
2732bool AddressSanitizer::maybeInsertDynamicShadowAtFunctionEntry(Function &F) {
2733 // Generate code only when dynamic addressing is needed.
2734 if (Mapping.Offset != kDynamicShadowSentinel)
2735 return false;
2736
2737 IRBuilder<> IRB(&F.front().front());
2738 if (Mapping.InGlobal) {
2740 // An empty inline asm with input reg == output reg.
2741 // An opaque pointer-to-int cast, basically.
2743 FunctionType::get(IntptrTy, {AsanShadowGlobal->getType()}, false),
2744 StringRef(""), StringRef("=r,0"),
2745 /*hasSideEffects=*/false);
2746 LocalDynamicShadow =
2747 IRB.CreateCall(Asm, {AsanShadowGlobal}, ".asan.shadow");
2748 } else {
2749 LocalDynamicShadow =
2750 IRB.CreatePointerCast(AsanShadowGlobal, IntptrTy, ".asan.shadow");
2751 }
2752 } else {
2753 Value *GlobalDynamicAddress = F.getParent()->getOrInsertGlobal(
2755 LocalDynamicShadow = IRB.CreateLoad(IntptrTy, GlobalDynamicAddress);
2756 }
2757 return true;
2758}
2759
2760void AddressSanitizer::markEscapedLocalAllocas(Function &F) {
2761 // Find the one possible call to llvm.localescape and pre-mark allocas passed
2762 // to it as uninteresting. This assumes we haven't started processing allocas
2763 // yet. This check is done up front because iterating the use list in
2764 // isInterestingAlloca would be algorithmically slower.
2765 assert(ProcessedAllocas.empty() && "must process localescape before allocas");
2766
2767 // Try to get the declaration of llvm.localescape. If it's not in the module,
2768 // we can exit early.
2769 if (!F.getParent()->getFunction("llvm.localescape")) return;
2770
2771 // Look for a call to llvm.localescape call in the entry block. It can't be in
2772 // any other block.
2773 for (Instruction &I : F.getEntryBlock()) {
2774 IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I);
2775 if (II && II->getIntrinsicID() == Intrinsic::localescape) {
2776 // We found a call. Mark all the allocas passed in as uninteresting.
2777 for (Value *Arg : II->args()) {
2778 AllocaInst *AI = dyn_cast<AllocaInst>(Arg->stripPointerCasts());
2779 assert(AI && AI->isStaticAlloca() &&
2780 "non-static alloca arg to localescape");
2781 ProcessedAllocas[AI] = false;
2782 }
2783 break;
2784 }
2785 }
2786}
2787
2788bool AddressSanitizer::suppressInstrumentationSiteForDebug(int &Instrumented) {
2789 bool ShouldInstrument =
2790 ClDebugMin < 0 || ClDebugMax < 0 ||
2791 (Instrumented >= ClDebugMin && Instrumented <= ClDebugMax);
2792 Instrumented++;
2793 return !ShouldInstrument;
2794}
2795
2796bool AddressSanitizer::instrumentFunction(Function &F,
2797 const TargetLibraryInfo *TLI) {
2798 if (F.empty())
2799 return false;
2800 if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
2801 if (!ClDebugFunc.empty() && ClDebugFunc == F.getName()) return false;
2802 if (F.getName().startswith("__asan_")) return false;
2803
2804 bool FunctionModified = false;
2805
2806 // If needed, insert __asan_init before checking for SanitizeAddress attr.
2807 // This function needs to be called even if the function body is not
2808 // instrumented.
2809 if (maybeInsertAsanInitAtFunctionEntry(F))
2810 FunctionModified = true;
2811
2812 // Leave if the function doesn't need instrumentation.
2813 if (!F.hasFnAttribute(Attribute::SanitizeAddress)) return FunctionModified;
2814
2815 if (F.hasFnAttribute(Attribute::DisableSanitizerInstrumentation))
2816 return FunctionModified;
2817
2818 LLVM_DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n");
2819
2820 initializeCallbacks(*F.getParent(), TLI);
2821
2822 FunctionStateRAII CleanupObj(this);
2823
2824 FunctionModified |= maybeInsertDynamicShadowAtFunctionEntry(F);
2825
2826 // We can't instrument allocas used with llvm.localescape. Only static allocas
2827 // can be passed to that intrinsic.
2828 markEscapedLocalAllocas(F);
2829
2830 // We want to instrument every address only once per basic block (unless there
2831 // are calls between uses).
2832 SmallPtrSet<Value *, 16> TempsToInstrument;
2833 SmallVector<InterestingMemoryOperand, 16> OperandsToInstrument;
2834 SmallVector<MemIntrinsic *, 16> IntrinToInstrument;
2835 SmallVector<Instruction *, 8> NoReturnCalls;
2837 SmallVector<Instruction *, 16> PointerComparisonsOrSubtracts;
2838
2839 // Fill the set of memory operations to instrument.
2840 for (auto &BB : F) {
2841 AllBlocks.push_back(&BB);
2842 TempsToInstrument.clear();
2843 int NumInsnsPerBB = 0;
2844 for (auto &Inst : BB) {
2845 if (LooksLikeCodeInBug11395(&Inst)) return false;
2846 // Skip instructions inserted by another instrumentation.
2847 if (Inst.hasMetadata(LLVMContext::MD_nosanitize))
2848 continue;
2849 SmallVector<InterestingMemoryOperand, 1> InterestingOperands;
2850 getInterestingMemoryOperands(&Inst, InterestingOperands);
2851
2852 if (!InterestingOperands.empty()) {
2853 for (auto &Operand : InterestingOperands) {
2854 if (ClOpt && ClOptSameTemp) {
2855 Value *Ptr = Operand.getPtr();
2856 // If we have a mask, skip instrumentation if we've already
2857 // instrumented the full object. But don't add to TempsToInstrument
2858 // because we might get another load/store with a different mask.
2859 if (Operand.MaybeMask) {
2860 if (TempsToInstrument.count(Ptr))
2861 continue; // We've seen this (whole) temp in the current BB.
2862 } else {
2863 if (!TempsToInstrument.insert(Ptr).second)
2864 continue; // We've seen this temp in the current BB.
2865 }
2866 }
2867 OperandsToInstrument.push_back(Operand);
2868 NumInsnsPerBB++;
2869 }
2870 } else if (((ClInvalidPointerPairs || ClInvalidPointerCmp) &&
2874 PointerComparisonsOrSubtracts.push_back(&Inst);
2875 } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(&Inst)) {
2876 // ok, take it.
2877 IntrinToInstrument.push_back(MI);
2878 NumInsnsPerBB++;
2879 } else {
2880 if (auto *CB = dyn_cast<CallBase>(&Inst)) {
2881 // A call inside BB.
2882 TempsToInstrument.clear();
2883 if (CB->doesNotReturn())
2884 NoReturnCalls.push_back(CB);
2885 }
2886 if (CallInst *CI = dyn_cast<CallInst>(&Inst))
2888 }
2889 if (NumInsnsPerBB >= ClMaxInsnsToInstrumentPerBB) break;
2890 }
2891 }
2892
2893 bool UseCalls = (ClInstrumentationWithCallsThreshold >= 0 &&
2894 OperandsToInstrument.size() + IntrinToInstrument.size() >
2896 const DataLayout &DL = F.getParent()->getDataLayout();
2897 ObjectSizeOpts ObjSizeOpts;
2898 ObjSizeOpts.RoundToAlign = true;
2899 ObjectSizeOffsetVisitor ObjSizeVis(DL, TLI, F.getContext(), ObjSizeOpts);
2900
2901 // Instrument.
2902 int NumInstrumented = 0;
2903 for (auto &Operand : OperandsToInstrument) {
2904 if (!suppressInstrumentationSiteForDebug(NumInstrumented))
2905 instrumentMop(ObjSizeVis, Operand, UseCalls,
2906 F.getParent()->getDataLayout());
2907 FunctionModified = true;
2908 }
2909 for (auto *Inst : IntrinToInstrument) {
2910 if (!suppressInstrumentationSiteForDebug(NumInstrumented))
2911 instrumentMemIntrinsic(Inst);
2912 FunctionModified = true;
2913 }
2914
2915 FunctionStackPoisoner FSP(F, *this);
2916 bool ChangedStack = FSP.runOnFunction();
2917
2918 // We must unpoison the stack before NoReturn calls (throw, _exit, etc).
2919 // See e.g. https://github.com/google/sanitizers/issues/37
2920 for (auto *CI : NoReturnCalls) {
2921 IRBuilder<> IRB(CI);
2922 IRB.CreateCall(AsanHandleNoReturnFunc, {});
2923 }
2924
2925 for (auto *Inst : PointerComparisonsOrSubtracts) {
2926 instrumentPointerComparisonOrSubtraction(Inst);
2927 FunctionModified = true;
2928 }
2929
2930 if (ChangedStack || !NoReturnCalls.empty())
2931 FunctionModified = true;
2932
2933 LLVM_DEBUG(dbgs() << "ASAN done instrumenting: " << FunctionModified << " "
2934 << F << "\n");
2935
2936 return FunctionModified;
2937}
2938
2939// Workaround for bug 11395: we don't want to instrument stack in functions
2940// with large assembly blobs (32-bit only), otherwise reg alloc may crash.
2941// FIXME: remove once the bug 11395 is fixed.
2942bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
2943 if (LongSize != 32) return false;
2944 CallInst *CI = dyn_cast<CallInst>(I);
2945 if (!CI || !CI->isInlineAsm()) return false;
2946 if (CI->arg_size() <= 5)
2947 return false;
2948 // We have inline assembly with quite a few arguments.
2949 return true;
2950}
2951
2952void FunctionStackPoisoner::initializeCallbacks(Module &M) {
2953 IRBuilder<> IRB(*C);
2954 if (ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Always ||
2955 ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Runtime) {
2956 const char *MallocNameTemplate =
2957 ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Always
2960 for (int Index = 0; Index <= kMaxAsanStackMallocSizeClass; Index++) {
2961 std::string Suffix = itostr(Index);
2962 AsanStackMallocFunc[Index] = M.getOrInsertFunction(
2963 MallocNameTemplate + Suffix, IntptrTy, IntptrTy);
2964 AsanStackFreeFunc[Index] =
2965 M.getOrInsertFunction(kAsanStackFreeNameTemplate + Suffix,
2966 IRB.getVoidTy(), IntptrTy, IntptrTy);
2967 }
2968 }
2969 if (ASan.UseAfterScope) {
2970 AsanPoisonStackMemoryFunc = M.getOrInsertFunction(
2971 kAsanPoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
2972 AsanUnpoisonStackMemoryFunc = M.getOrInsertFunction(
2973 kAsanUnpoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
2974 }
2975
2976 for (size_t Val : {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0xf1, 0xf2,
2977 0xf3, 0xf5, 0xf8}) {
2978 std::ostringstream Name;
2980 Name << std::setw(2) << std::setfill('0') << std::hex << Val;
2981 AsanSetShadowFunc[Val] =
2982 M.getOrInsertFunction(Name.str(), IRB.getVoidTy(), IntptrTy, IntptrTy);
2983 }
2984
2985 AsanAllocaPoisonFunc = M.getOrInsertFunction(
2986 kAsanAllocaPoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
2987 AsanAllocasUnpoisonFunc = M.getOrInsertFunction(
2988 kAsanAllocasUnpoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
2989}
2990
2991void FunctionStackPoisoner::copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
2992 ArrayRef<uint8_t> ShadowBytes,
2993 size_t Begin, size_t End,
2994 IRBuilder<> &IRB,
2995 Value *ShadowBase) {
2996 if (Begin >= End)
2997 return;
2998
2999 const size_t LargestStoreSizeInBytes =
3000 std::min<size_t>(sizeof(uint64_t), ASan.LongSize / 8);
3001
3002 const bool IsLittleEndian = F.getParent()->getDataLayout().isLittleEndian();
3003
3004 // Poison given range in shadow using larges store size with out leading and
3005 // trailing zeros in ShadowMask. Zeros never change, so they need neither
3006 // poisoning nor up-poisoning. Still we don't mind if some of them get into a
3007 // middle of a store.
3008 for (size_t i = Begin; i < End;) {
3009 if (!ShadowMask[i]) {
3010 assert(!ShadowBytes[i]);
3011 ++i;
3012 continue;
3013 }
3014
3015 size_t StoreSizeInBytes = LargestStoreSizeInBytes;
3016 // Fit store size into the range.
3017 while (StoreSizeInBytes > End - i)
3018 StoreSizeInBytes /= 2;
3019
3020 // Minimize store size by trimming trailing zeros.
3021 for (size_t j = StoreSizeInBytes - 1; j && !ShadowMask[i + j]; --j) {
3022 while (j <= StoreSizeInBytes / 2)
3023 StoreSizeInBytes /= 2;
3024 }
3025
3026 uint64_t Val = 0;
3027 for (size_t j = 0; j < StoreSizeInBytes; j++) {
3028 if (IsLittleEndian)
3029 Val |= (uint64_t)ShadowBytes[i + j] << (8 * j);
3030 else
3031 Val = (Val << 8) | ShadowBytes[i + j];
3032 }
3033
3034 Value *Ptr = IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i));
3035 Value *Poison = IRB.getIntN(StoreSizeInBytes * 8, Val);
3037 Poison, IRB.CreateIntToPtr(Ptr, Poison->getType()->getPointerTo()),
3038 Align(1));
3039
3040 i += StoreSizeInBytes;
3041 }
3042}
3043
3044void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
3045 ArrayRef<uint8_t> ShadowBytes,
3046 IRBuilder<> &IRB, Value *ShadowBase) {
3047 copyToShadow(ShadowMask, ShadowBytes, 0, ShadowMask.size(), IRB, ShadowBase);
3048}
3049
3050void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
3051 ArrayRef<uint8_t> ShadowBytes,
3052 size_t Begin, size_t End,
3053 IRBuilder<> &IRB, Value *ShadowBase) {
3054 assert(ShadowMask.size() == ShadowBytes.size());
3055 size_t Done = Begin;
3056 for (size_t i = Begin, j = Begin + 1; i < End; i = j++) {
3057 if (!ShadowMask[i]) {
3058 assert(!ShadowBytes[i]);
3059 continue;
3060 }
3061 uint8_t Val = ShadowBytes[i];
3062 if (!AsanSetShadowFunc[Val])
3063 continue;
3064
3065 // Skip same values.
3066 for (; j < End && ShadowMask[j] && Val == ShadowBytes[j]; ++j) {
3067 }
3068
3069 if (j - i >= ClMaxInlinePoisoningSize) {
3070 copyToShadowInline(ShadowMask, ShadowBytes, Done, i, IRB, ShadowBase);
3071 IRB.CreateCall(AsanSetShadowFunc[Val],
3072 {IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i)),
3073 ConstantInt::get(IntptrTy, j - i)});
3074 Done = j;
3075 }
3076 }
3077
3078 copyToShadowInline(ShadowMask, ShadowBytes, Done, End, IRB, ShadowBase);
3079}
3080
3081// Fake stack allocator (asan_fake_stack.h) has 11 size classes
3082// for every power of 2 from kMinStackMallocSize to kMaxAsanStackMallocSizeClass
3083static int StackMallocSizeClass(uint64_t LocalStackSize) {
3084 assert(LocalStackSize <= kMaxStackMallocSize);
3085 uint64_t MaxSize = kMinStackMallocSize;
3086 for (int i = 0;; i++, MaxSize *= 2)
3087 if (LocalStackSize <= MaxSize) return i;
3088 llvm_unreachable("impossible LocalStackSize");
3089}
3090
3091void FunctionStackPoisoner::copyArgsPassedByValToAllocas() {
3092 Instruction *CopyInsertPoint = &F.front().front();
3093 if (CopyInsertPoint == ASan.LocalDynamicShadow) {
3094 // Insert after the dynamic shadow location is determined
3095 CopyInsertPoint = CopyInsertPoint->getNextNode();
3096 assert(CopyInsertPoint);
3097 }
3098 IRBuilder<> IRB(CopyInsertPoint);
3099 const DataLayout &DL = F.getParent()->getDataLayout();
3100 for (Argument &Arg : F.args()) {
3101 if (Arg.hasByValAttr()) {
3102 Type *Ty = Arg.getParamByValType();
3103 const Align Alignment =
3104 DL.getValueOrABITypeAlignment(Arg.getParamAlign(), Ty);
3105
3106 AllocaInst *AI = IRB.CreateAlloca(
3107 Ty, nullptr,
3108 (Arg.hasName() ? Arg.getName() : "Arg" + Twine(Arg.getArgNo())) +
3109 ".byval");
3110 AI->setAlignment(Alignment);
3111 Arg.replaceAllUsesWith(AI);
3112
3113 uint64_t AllocSize = DL.getTypeAllocSize(Ty);
3114 IRB.CreateMemCpy(AI, Alignment, &Arg, Alignment, AllocSize);
3115 }
3116 }
3117}
3118
3119PHINode *FunctionStackPoisoner::createPHI(IRBuilder<> &IRB, Value *Cond,
3120 Value *ValueIfTrue,
3121 Instruction *ThenTerm,
3122 Value *ValueIfFalse) {
3123 PHINode *PHI = IRB.CreatePHI(IntptrTy, 2);
3124 BasicBlock *CondBlock = cast<Instruction>(Cond)->getParent();
3125 PHI->addIncoming(ValueIfFalse, CondBlock);
3126 BasicBlock *ThenBlock = ThenTerm->getParent();
3127 PHI->addIncoming(ValueIfTrue, ThenBlock);
3128 return PHI;
3129}
3130
3131Value *FunctionStackPoisoner::createAllocaForLayout(
3132 IRBuilder<> &IRB, const ASanStackFrameLayout &L, bool Dynamic) {
3133 AllocaInst *Alloca;
3134 if (Dynamic) {
3135 Alloca = IRB.CreateAlloca(IRB.getInt8Ty(),
3136 ConstantInt::get(IRB.getInt64Ty(), L.FrameSize),
3137 "MyAlloca");
3138 } else {
3139 Alloca = IRB.CreateAlloca(ArrayType::get(IRB.getInt8Ty(), L.FrameSize),
3140 nullptr, "MyAlloca");
3141 assert(Alloca->isStaticAlloca());
3142 }
3143 assert((ClRealignStack & (ClRealignStack - 1)) == 0);
3144 uint64_t FrameAlignment = std::max(L.FrameAlignment, uint64_t(ClRealignStack));
3145 Alloca->setAlignment(Align(FrameAlignment));
3146 return IRB.CreatePointerCast(Alloca, IntptrTy);
3147}
3148
3149void FunctionStackPoisoner::createDynamicAllocasInitStorage() {
3150 BasicBlock &FirstBB = *F.begin();
3151 IRBuilder<> IRB(dyn_cast<Instruction>(FirstBB.begin()));
3152 DynamicAllocaLayout = IRB.CreateAlloca(IntptrTy, nullptr);
3153 IRB.CreateStore(Constant::getNullValue(IntptrTy), DynamicAllocaLayout);
3154 DynamicAllocaLayout->setAlignment(Align(32));
3155}
3156
3157void FunctionStackPoisoner::processDynamicAllocas() {
3158 if (!ClInstrumentDynamicAllocas || DynamicAllocaVec.empty()) {
3159 assert(DynamicAllocaPoisonCallVec.empty());
3160 return;
3161 }
3162
3163 // Insert poison calls for lifetime intrinsics for dynamic allocas.
3164 for (const auto &APC : DynamicAllocaPoisonCallVec) {
3165 assert(APC.InsBefore);
3166 assert(APC.AI);
3167 assert(ASan.isInterestingAlloca(*APC.AI));
3168 assert(!APC.AI->isStaticAlloca());
3169
3170 IRBuilder<> IRB(APC.InsBefore);
3171 poisonAlloca(APC.AI, APC.Size, IRB, APC.DoPoison);
3172 // Dynamic allocas will be unpoisoned unconditionally below in
3173 // unpoisonDynamicAllocas.
3174 // Flag that we need unpoison static allocas.
3175 }
3176
3177 // Handle dynamic allocas.
3178 createDynamicAllocasInitStorage();
3179 for (auto &AI : DynamicAllocaVec)
3180 handleDynamicAllocaCall(AI);
3181 unpoisonDynamicAllocas();
3182}
3183
3184/// Collect instructions in the entry block after \p InsBefore which initialize
3185/// permanent storage for a function argument. These instructions must remain in
3186/// the entry block so that uninitialized values do not appear in backtraces. An
3187/// added benefit is that this conserves spill slots. This does not move stores
3188/// before instrumented / "interesting" allocas.
3190 AddressSanitizer &ASan, Instruction &InsBefore,
3191 SmallVectorImpl<Instruction *> &InitInsts) {
3192 Instruction *Start = InsBefore.getNextNonDebugInstruction();
3193 for (Instruction *It = Start; It; It = It->getNextNonDebugInstruction()) {
3194 // Argument initialization looks like:
3195 // 1) store <Argument>, <Alloca> OR
3196 // 2) <CastArgument> = cast <Argument> to ...
3197 // store <CastArgument> to <Alloca>
3198 // Do not consider any other kind of instruction.
3199 //
3200 // Note: This covers all known cases, but may not be exhaustive. An
3201 // alternative to pattern-matching stores is to DFS over all Argument uses:
3202 // this might be more general, but is probably much more complicated.
3203 if (isa<AllocaInst>(It) || isa<CastInst>(It))
3204 continue;
3205 if (auto *Store = dyn_cast<StoreInst>(It)) {
3206 // The store destination must be an alloca that isn't interesting for
3207 // ASan to instrument. These are moved up before InsBefore, and they're
3208 // not interesting because allocas for arguments can be mem2reg'd.
3209 auto *Alloca = dyn_cast<AllocaInst>(Store->getPointerOperand());
3210 if (!Alloca || ASan.isInterestingAlloca(*Alloca))
3211 continue;
3212
3213 Value *Val = Store->getValueOperand();
3214 bool IsDirectArgInit = isa<Argument>(Val);
3215 bool IsArgInitViaCast =
3216 isa<CastInst>(Val) &&
3217 isa<Argument>(cast<CastInst>(Val)->getOperand(0)) &&
3218 // Check that the cast appears directly before the store. Otherwise
3219 // moving the cast before InsBefore may break the IR.
3220 Val == It->getPrevNonDebugInstruction();
3221 bool IsArgInit = IsDirectArgInit || IsArgInitViaCast;
3222 if (!IsArgInit)
3223 continue;
3224
3225 if (IsArgInitViaCast)
3226 InitInsts.push_back(cast<Instruction>(Val));
3227 InitInsts.push_back(Store);
3228 continue;
3229 }
3230
3231 // Do not reorder past unknown instructions: argument initialization should
3232 // only involve casts and stores.
3233 return;
3234 }
3235}
3236
3237void FunctionStackPoisoner::processStaticAllocas() {
3238 if (AllocaVec.empty()) {
3239 assert(StaticAllocaPoisonCallVec.empty());
3240 return;
3241 }
3242
3243 int StackMallocIdx = -1;
3244 DebugLoc EntryDebugLocation;
3245 if (auto SP = F.getSubprogram())
3246 EntryDebugLocation =
3247 DILocation::get(SP->getContext(), SP->getScopeLine(), 0, SP);
3248
3249 Instruction *InsBefore = AllocaVec[0];
3250 IRBuilder<> IRB(InsBefore);
3251
3252 // Make sure non-instrumented allocas stay in the entry block. Otherwise,
3253 // debug info is broken, because only entry-block allocas are treated as
3254 // regular stack slots.
3255 auto InsBeforeB = InsBefore->getParent();
3256 assert(InsBeforeB == &F.getEntryBlock());
3257 for (auto *AI : StaticAllocasToMoveUp)
3258 if (AI->getParent() == InsBeforeB)
3259 AI->moveBefore(InsBefore);
3260
3261 // Move stores of arguments into entry-block allocas as well. This prevents
3262 // extra stack slots from being generated (to house the argument values until
3263 // they can be stored into the allocas). This also prevents uninitialized
3264 // values from being shown in backtraces.
3265 SmallVector<Instruction *, 8> ArgInitInsts;
3266 findStoresToUninstrumentedArgAllocas(ASan, *InsBefore, ArgInitInsts);
3267 for (Instruction *ArgInitInst : ArgInitInsts)
3268 ArgInitInst->moveBefore(InsBefore);
3269
3270 // If we have a call to llvm.localescape, keep it in the entry block.
3271 if (LocalEscapeCall) LocalEscapeCall->moveBefore(InsBefore);
3272
3274 SVD.reserve(AllocaVec.size());
3275 for (AllocaInst *AI : AllocaVec) {
3277 ASan.getAllocaSizeInBytes(*AI),
3278 0,
3279 AI->getAlign().value(),
3280 AI,
3281 0,
3282 0};
3283 SVD.push_back(D);
3284 }
3285
3286 // Minimal header size (left redzone) is 4 pointers,
3287 // i.e. 32 bytes on 64-bit platforms and 16 bytes in 32-bit platforms.
3288 uint64_t Granularity = 1ULL << Mapping.Scale;
3289 uint64_t MinHeaderSize = std::max((uint64_t)ASan.LongSize / 2, Granularity);
3290 const ASanStackFrameLayout &L =
3291 ComputeASanStackFrameLayout(SVD, Granularity, MinHeaderSize);
3292
3293 // Build AllocaToSVDMap for ASanStackVariableDescription lookup.
3295 for (auto &Desc : SVD)
3296 AllocaToSVDMap[Desc.AI] = &Desc;
3297
3298 // Update SVD with information from lifetime intrinsics.
3299 for (const auto &APC : StaticAllocaPoisonCallVec) {
3300 assert(APC.InsBefore);
3301 assert(APC.AI);
3302 assert(ASan.isInterestingAlloca(*APC.AI));
3303 assert(APC.AI->isStaticAlloca());
3304
3305 ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
3306 Desc.LifetimeSize = Desc.Size;
3307 if (const DILocation *FnLoc = EntryDebugLocation.get()) {
3308 if (const DILocation *LifetimeLoc = APC.InsBefore->getDebugLoc().get()) {
3309 if (LifetimeLoc->getFile() == FnLoc->getFile())
3310 if (unsigned Line = LifetimeLoc->getLine())
3311 Desc.Line = std::min(Desc.Line ? Desc.Line : Line, Line);
3312 }
3313 }
3314 }
3315
3316 auto DescriptionString = ComputeASanStackFrameDescription(SVD);
3317 LLVM_DEBUG(dbgs() << DescriptionString << " --- " << L.FrameSize << "\n");
3318 uint64_t LocalStackSize = L.FrameSize;
3319 bool DoStackMalloc =
3320 ASan.UseAfterReturn != AsanDetectStackUseAfterReturnMode::Never &&
3321 !ASan.CompileKernel && LocalStackSize <= kMaxStackMallocSize;
3322 bool DoDynamicAlloca = ClDynamicAllocaStack;
3323 // Don't do dynamic alloca or stack malloc if:
3324 // 1) There is inline asm: too often it makes assumptions on which registers
3325 // are available.
3326 // 2) There is a returns_twice call (typically setjmp), which is
3327 // optimization-hostile, and doesn't play well with introduced indirect
3328 // register-relative calculation of local variable addresses.
3329 DoDynamicAlloca &= !HasInlineAsm && !HasReturnsTwiceCall;
3330 DoStackMalloc &= !HasInlineAsm && !HasReturnsTwiceCall;
3331
3332 Value *StaticAlloca =
3333 DoDynamicAlloca ? nullptr : createAllocaForLayout(IRB, L, false);
3334
3335 Value *FakeStack;
3336 Value *LocalStackBase;
3337 Value *LocalStackBaseAlloca;
3338 uint8_t DIExprFlags = DIExpression::ApplyOffset;
3339
3340 if (DoStackMalloc) {
3341 LocalStackBaseAlloca =
3342 IRB.CreateAlloca(IntptrTy, nullptr, "asan_local_stack_base");
3343 if (ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Runtime) {
3344 // void *FakeStack = __asan_option_detect_stack_use_after_return
3345 // ? __asan_stack_malloc_N(LocalStackSize)
3346 // : nullptr;
3347 // void *LocalStackBase = (FakeStack) ? FakeStack :
3348 // alloca(LocalStackSize);
3349 Constant *OptionDetectUseAfterReturn = F.getParent()->getOrInsertGlobal(
3351 Value *UseAfterReturnIsEnabled = IRB.CreateICmpNE(
3352 IRB.CreateLoad(IRB.getInt32Ty(), OptionDetectUseAfterReturn),
3354 Instruction *Term =
3355 SplitBlockAndInsertIfThen(UseAfterReturnIsEnabled, InsBefore, false);
3356 IRBuilder<> IRBIf(Term);
3357 StackMallocIdx = StackMallocSizeClass(LocalStackSize);
3358 assert(StackMallocIdx <= kMaxAsanStackMallocSizeClass);
3359 Value *FakeStackValue =
3360 IRBIf.CreateCall(AsanStackMallocFunc[StackMallocIdx],
3361 ConstantInt::get(IntptrTy, LocalStackSize));
3362 IRB.SetInsertPoint(InsBefore);
3363 FakeStack = createPHI(IRB, UseAfterReturnIsEnabled, FakeStackValue, Term,
3364 ConstantInt::get(IntptrTy, 0));
3365 } else {
3366 // assert(ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode:Always)
3367 // void *FakeStack = __asan_stack_malloc_N(LocalStackSize);
3368 // void *LocalStackBase = (FakeStack) ? FakeStack :
3369 // alloca(LocalStackSize);
3370 StackMallocIdx = StackMallocSizeClass(LocalStackSize);
3371 FakeStack = IRB.CreateCall(AsanStackMallocFunc[StackMallocIdx],
3372 ConstantInt::get(IntptrTy, LocalStackSize));
3373 }
3374 Value *NoFakeStack =
3375 IRB.CreateICmpEQ(FakeStack, Constant::getNullValue(IntptrTy));
3376 Instruction *Term =
3377 SplitBlockAndInsertIfThen(NoFakeStack, InsBefore, false);
3378 IRBuilder<> IRBIf(Term);
3379 Value *AllocaValue =
3380 DoDynamicAlloca ? createAllocaForLayout(IRBIf, L, true) : StaticAlloca;
3381
3382 IRB.SetInsertPoint(InsBefore);
3383 LocalStackBase = createPHI(IRB, NoFakeStack, AllocaValue, Term, FakeStack);
3384 IRB.CreateStore(LocalStackBase, LocalStackBaseAlloca);
3385 DIExprFlags |= DIExpression::DerefBefore;
3386 } else {
3387 // void *FakeStack = nullptr;
3388 // void *LocalStackBase = alloca(LocalStackSize);
3389 FakeStack = ConstantInt::get(IntptrTy, 0);
3390 LocalStackBase =
3391 DoDynamicAlloca ? createAllocaForLayout(IRB, L, true) : StaticAlloca;
3392 LocalStackBaseAlloca = LocalStackBase;
3393 }
3394
3395 // It shouldn't matter whether we pass an `alloca` or a `ptrtoint` as the
3396 // dbg.declare address opereand, but passing a `ptrtoint` seems to confuse
3397 // later passes and can result in dropped variable coverage in debug info.
3398 Value *LocalStackBaseAllocaPtr =
3399 isa<PtrToIntInst>(LocalStackBaseAlloca)
3400 ? cast<PtrToIntInst>(LocalStackBaseAlloca)->getPointerOperand()
3401 : LocalStackBaseAlloca;
3402 assert(isa<AllocaInst>(LocalStackBaseAllocaPtr) &&
3403 "Variable descriptions relative to ASan stack base will be dropped");
3404
3405 // Replace Alloca instructions with base+offset.
3406 for (const auto &Desc : SVD) {
3407 AllocaInst *AI = Desc.AI;
3408 replaceDbgDeclare(AI, LocalStackBaseAllocaPtr, DIB, DIExprFlags,
3409 Desc.Offset);
3410 Value *NewAllocaPtr = IRB.CreateIntToPtr(
3411 IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Desc.Offset)),
3412 AI->getType());
3413 AI->replaceAllUsesWith(NewAllocaPtr);
3414 }
3415
3416 // The left-most redzone has enough space for at least 4 pointers.
3417 // Write the Magic value to redzone[0].
3418 Value *BasePlus0 = IRB.CreateIntToPtr(LocalStackBase, IntptrPtrTy);
3420 BasePlus0);
3421 // Write the frame description constant to redzone[1].
3422 Value *BasePlus1 = IRB.CreateIntToPtr(
3423 IRB.CreateAdd(LocalStackBase,
3424 ConstantInt::get(IntptrTy, ASan.LongSize / 8)),
3425 IntptrPtrTy);
3426 GlobalVariable *StackDescriptionGlobal =
3427 createPrivateGlobalForString(*F.getParent(), DescriptionString,
3428 /*AllowMerging*/ true, kAsanGenPrefix);
3429 Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal, IntptrTy);
3430 IRB.CreateStore(Description, BasePlus1);
3431 // Write the PC to redzone[2].
3432 Value *BasePlus2 = IRB.CreateIntToPtr(
3433 IRB.CreateAdd(LocalStackBase,
3434 ConstantInt::get(IntptrTy, 2 * ASan.LongSize / 8)),
3435 IntptrPtrTy);
3436 IRB.CreateStore(IRB.CreatePointerCast(&F, IntptrTy), BasePlus2);
3437
3438 const auto &ShadowAfterScope = GetShadowBytesAfterScope(SVD, L);
3439
3440 // Poison the stack red zones at the entry.
3441 Value *ShadowBase = ASan.memToShadow(LocalStackBase, IRB);
3442 // As mask we must use most poisoned case: red zones and after scope.
3443 // As bytes we can use either the same or just red zones only.
3444 copyToShadow(ShadowAfterScope, ShadowAfterScope, IRB, ShadowBase);
3445
3446 if (!StaticAllocaPoisonCallVec.empty()) {
3447 const auto &ShadowInScope = GetShadowBytes(SVD, L);
3448
3449 // Poison static allocas near lifetime intrinsics.
3450 for (const auto &APC : StaticAllocaPoisonCallVec) {
3451 const ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
3452 assert(Desc.Offset % L.Granularity == 0);
3453 size_t Begin = Desc.Offset / L.Granularity;
3454 size_t End = Begin + (APC.Size + L.Granularity - 1) / L.Granularity;
3455
3456 IRBuilder<> IRB(APC.InsBefore);
3457 copyToShadow(ShadowAfterScope,
3458 APC.DoPoison ? ShadowAfterScope : ShadowInScope, Begin, End,
3459 IRB, ShadowBase);
3460 }
3461 }
3462
3463 SmallVector<uint8_t, 64> ShadowClean(ShadowAfterScope.size(), 0);
3464 SmallVector<uint8_t, 64> ShadowAfterReturn;
3465
3466 // (Un)poison the stack before all ret instructions.
3467 for (Instruction *Ret : RetVec) {
3468 IRBuilder<> IRBRet(Ret);
3469 // Mark the current frame as retired.
3470 IRBRet.CreateStore(ConstantInt::get(IntptrTy, kRetiredStackFrameMagic),
3471 BasePlus0);
3472 if (DoStackMalloc) {
3473 assert(StackMallocIdx >= 0);
3474 // if FakeStack != 0 // LocalStackBase == FakeStack
3475 // // In use-after-return mode, poison the whole stack frame.
3476 // if StackMallocIdx <= 4
3477 // // For small sizes inline the whole thing:
3478 // memset(ShadowBase, kAsanStackAfterReturnMagic, ShadowSize);
3479 // **SavedFlagPtr(FakeStack) = 0
3480 // else
3481 // __asan_stack_free_N(FakeStack, LocalStackSize)
3482 // else
3483 // <This is not a fake stack; unpoison the redzones>
3484 Value *Cmp =
3485 IRBRet.CreateICmpNE(FakeStack, Constant::getNullValue(IntptrTy));
3486 Instruction *ThenTerm, *ElseTerm;
3487 SplitBlockAndInsertIfThenElse(Cmp, Ret, &ThenTerm, &ElseTerm);
3488
3489 IRBuilder<> IRBPoison(ThenTerm);
3490 if (StackMallocIdx <= 4) {
3491 int ClassSize = kMinStackMallocSize << StackMallocIdx;
3492 ShadowAfterReturn.resize(ClassSize / L.Granularity,
3494 copyToShadow(ShadowAfterReturn, ShadowAfterReturn, IRBPoison,
3495 ShadowBase);
3496 Value *SavedFlagPtrPtr = IRBPoison.CreateAdd(
3497 FakeStack,
3498 ConstantInt::get(IntptrTy, ClassSize - ASan.LongSize / 8));
3499 Value *SavedFlagPtr = IRBPoison.CreateLoad(
3500 IntptrTy, IRBPoison.CreateIntToPtr(SavedFlagPtrPtr, IntptrPtrTy));
3501 IRBPoison.CreateStore(
3502 Constant::getNullValue(IRBPoison.getInt8Ty()),
3503 IRBPoison.CreateIntToPtr(SavedFlagPtr, IRBPoison.getInt8PtrTy()));
3504 } else {
3505 // For larger frames call __asan_stack_free_*.
3506 IRBPoison.CreateCall(
3507 AsanStackFreeFunc[StackMallocIdx],
3508 {FakeStack, ConstantInt::get(IntptrTy, LocalStackSize)});
3509 }
3510
3511 IRBuilder<> IRBElse(ElseTerm);
3512 copyToShadow(ShadowAfterScope, ShadowClean, IRBElse, ShadowBase);
3513 } else {
3514 copyToShadow(ShadowAfterScope, ShadowClean, IRBRet, ShadowBase);
3515 }
3516 }
3517
3518 // We are done. Remove the old unused alloca instructions.
3519 for (auto *AI : AllocaVec)
3520 AI->eraseFromParent();
3521}
3522
3523void FunctionStackPoisoner::poisonAlloca(Value *V, uint64_t Size,
3524 IRBuilder<> &IRB, bool DoPoison) {
3525 // For now just insert the call to ASan runtime.
3526 Value *AddrArg = IRB.CreatePointerCast(V, IntptrTy);
3527 Value *SizeArg = ConstantInt::get(IntptrTy, Size);
3528 IRB.CreateCall(
3529 DoPoison ? AsanPoisonStackMemoryFunc : AsanUnpoisonStackMemoryFunc,
3530 {AddrArg, SizeArg});
3531}
3532
3533// Handling llvm.lifetime intrinsics for a given %alloca:
3534// (1) collect all llvm.lifetime.xxx(%size, %value) describing the alloca.
3535// (2) if %size is constant, poison memory for llvm.lifetime.end (to detect
3536// invalid accesses) and unpoison it for llvm.lifetime.start (the memory
3537// could be poisoned by previous llvm.lifetime.end instruction, as the
3538// variable may go in and out of scope several times, e.g. in loops).
3539// (3) if we poisoned at least one %alloca in a function,
3540// unpoison the whole stack frame at function exit.
3541void FunctionStackPoisoner::handleDynamicAllocaCall(AllocaInst *AI) {
3542 IRBuilder<> IRB(AI);
3543
3544 const Align Alignment = std::max(Align(kAllocaRzSize), AI->getAlign());
3545 const uint64_t AllocaRedzoneMask = kAllocaRzSize - 1;
3546
3547 Value *Zero = Constant::getNullValue(IntptrTy);
3548 Value *AllocaRzSize = ConstantInt::get(IntptrTy, kAllocaRzSize);
3549 Value *AllocaRzMask = ConstantInt::get(IntptrTy, AllocaRedzoneMask);
3550
3551 // Since we need to extend alloca with additional memory to locate
3552 // redzones, and OldSize is number of allocated blocks with
3553 // ElementSize size, get allocated memory size in bytes by
3554 // OldSize * ElementSize.
3555 const unsigned ElementSize =
3556 F.getParent()->getDataLayout().getTypeAllocSize(AI->getAllocatedType());
3557 Value *OldSize =
3558 IRB.CreateMul(IRB.CreateIntCast(AI->getArraySize(), IntptrTy, false),
3559 ConstantInt::get(IntptrTy, ElementSize));
3560
3561 // PartialSize = OldSize % 32
3562 Value *PartialSize = IRB.CreateAnd(OldSize, AllocaRzMask);
3563
3564 // Misalign = kAllocaRzSize - PartialSize;
3565 Value *Misalign = IRB.CreateSub(AllocaRzSize, PartialSize);
3566
3567 // PartialPadding = Misalign != kAllocaRzSize ? Misalign : 0;
3568 Value *Cond = IRB.CreateICmpNE(Misalign, AllocaRzSize);
3569 Value *PartialPadding = IRB.CreateSelect(Cond, Misalign, Zero);
3570
3571 // AdditionalChunkSize = Alignment + PartialPadding + kAllocaRzSize
3572 // Alignment is added to locate left redzone, PartialPadding for possible
3573 // partial redzone and kAllocaRzSize for right redzone respectively.
3574 Value *AdditionalChunkSize = IRB.CreateAdd(
3575 ConstantInt::get(IntptrTy, Alignment.value() + kAllocaRzSize),
3576 PartialPadding);
3577
3578 Value *NewSize = IRB.CreateAdd(OldSize, AdditionalChunkSize);
3579
3580 // Insert new alloca with new NewSize and Alignment params.
3581 AllocaInst *NewAlloca = IRB.CreateAlloca(IRB.getInt8Ty(), NewSize);
3582 NewAlloca->setAlignment(Alignment);
3583
3584 // NewAddress = Address + Alignment
3585 Value *NewAddress =
3586 IRB.CreateAdd(IRB.CreatePtrToInt(NewAlloca, IntptrTy),
3587 ConstantInt::get(IntptrTy, Alignment.value()));
3588
3589 // Insert __asan_alloca_poison call for new created alloca.
3590 IRB.CreateCall(AsanAllocaPoisonFunc, {NewAddress, OldSize});
3591
3592 // Store the last alloca's address to DynamicAllocaLayout. We'll need this
3593 // for unpoisoning stuff.
3594 IRB.CreateStore(IRB.CreatePtrToInt(NewAlloca, IntptrTy), DynamicAllocaLayout);
3595
3596 Value *NewAddressPtr = IRB.CreateIntToPtr(NewAddress, AI->getType());
3597
3598 // Replace all uses of AddessReturnedByAlloca with NewAddressPtr.
3599 AI->replaceAllUsesWith(NewAddressPtr);
3600
3601 // We are done. Erase old alloca from parent.
3602 AI->eraseFromParent();
3603}
3604
3605// isSafeAccess returns true if Addr is always inbounds with respect to its
3606// base object. For example, it is a field access or an array access with
3607// constant inbounds index.
3608bool AddressSanitizer::isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis,
3609 Value *Addr, TypeSize TypeStoreSize) const {
3610 if (TypeStoreSize.isScalable())
3611 // TODO: We can use vscale_range to convert a scalable value to an
3612 // upper bound on the access size.
3613 return false;
3614 SizeOffsetType SizeOffset = ObjSizeVis.compute(Addr);
3615 if (!ObjSizeVis.bothKnown(SizeOffset)) return false;
3616 uint64_t Size = SizeOffset.first.getZExtValue();
3617 int64_t Offset = SizeOffset.second.getSExtValue();
3618 // Three checks are required to ensure safety:
3619 // . Offset >= 0 (since the offset is given from the base ptr)
3620 // . Size >= Offset (unsigned)
3621 // . Size - Offset >= NeededSize (unsigned)
3622 return Offset >= 0 && Size >= uint64_t(Offset) &&
3623 Size - uint64_t(Offset) >= TypeStoreSize / 8;
3624}
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"))
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
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)
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
#define clEnumValN(ENUMVAL, FLAGNAME, DESC)
Definition: CommandLine.h:680
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
bool End
Definition: ELF_riscv.cpp:469
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
const SmallVectorImpl< MachineOperand > & Cond
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:165
static ArrayType * get(Type *ElementType, uint64_t NumElements)
This static method is the primary way to construct an ArrayType.
Definition: Type.cpp:648
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:573
LLVM Basic Block Representation.
Definition: BasicBlock.h:56
iterator begin()
Instruction iterator methods.
Definition: BasicBlock.h:335
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:257
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:149
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:1190
bool isInlineAsm() const
Check if this call is an inline asm statement.
Definition: InstrTypes.h:1479
Value * getArgOperand(unsigned i) const
Definition: InstrTypes.h:1357
iterator_range< User::op_iterator > args()
Iteration adapter for range-for loops.
Definition: InstrTypes.h:1348
bool doesNotReturn() const
Determine if the call cannot return.
Definition: InstrTypes.h:1919
unsigned arg_size() const
Definition: InstrTypes.h:1355
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:408
static Constant * get(ArrayType *T, ArrayRef< Constant * > V)
Definition: Constants.cpp:1235
static Constant * getIntToPtr(Constant *C, Type *Ty, bool OnlyIfReduced=false)
Definition: Constants.cpp:2199
static Constant * getPointerCast(Constant *C, Type *Ty)
Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant expression.
Definition: Constants.cpp:2025
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:1225
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:1504
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:1300
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.
This class represents an Operation in the Expression.
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:770
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:337
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:506
void setAlignment(Align Align)
Sets the alignment attribute of the GlobalObject.
Definition: Globals.cpp:128
void copyMetadata(const GlobalObject *Src, unsigned Offset)
Copy metadata from Src, adjusting offsets by Offset.
Definition: Metadata.cpp:1652
void setComdat(Comdat *C)
Definition: Globals.cpp:196
void setSection(StringRef S)
Change the section for this global.
Definition: Globals.cpp:250
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:481
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:1769
IntegerType * getInt1Ty()
Fetch the type representing a single bit.
Definition: IRBuilder.h:497
Value * CreateExtractElement(Value *Vec, Value *Idx, const Twine &Name="")
Definition: IRBuilder.h:2422
LoadInst * CreateAlignedLoad(Type *Ty, Value *Ptr, MaybeAlign Align, const char *Name)
Definition: IRBuilder.h:1803
Value * CreatePointerCast(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:2135
Value * CreateICmpSGE(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:2231
Value * CreateSelect(Value *C, Value *True, Value *False, const Twine &Name="", Instruction *MDFrom=nullptr)
Definition: IRBuilder.cpp:1119
BasicBlock::iterator GetInsertPoint() const
Definition: IRBuilder.h:175
Value * CreateIntToPtr(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:2084
Value * CreateTypeSize(Type *DstType, TypeSize Size)
Create an expression which evaluates to the number of units in Size at runtime.
Definition: IRBuilder.cpp:104
Value * CreateLShr(Value *LHS, Value *RHS, const Twine &Name="", bool isExact=false)
Definition: IRBuilder.h:1428
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:2207
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:2359
Value * CreateNot(Value *V, const Twine &Name="")
Definition: IRBuilder.h:1745
Value * CreateICmpEQ(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:2203
Value * CreateSub(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1335
Value * CreateBitCast(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:2089
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:1786
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:1466
StoreInst * CreateStore(Value *Val, Value *Ptr, bool isVolatile=false)
Definition: IRBuilder.h:1799
Value * CreateAdd(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1318
Value * CreatePtrToInt(Value *V, Type *DestTy, const Twine &Name="")
Definition: IRBuilder.h:2079
Value * CreateIsNotNull(Value *Arg, const Twine &Name="")
Return a boolean value testing if Arg != 0.
Definition: IRBuilder.h:2511
Value * CreateOr(Value *LHS, Value *RHS, const Twine &Name="")
Definition: IRBuilder.h:1488
Value * CreateIntCast(Value *V, Type *DestTy, bool isSigned, const Twine &Name="")
Definition: IRBuilder.h:2158
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:1822
CallInst * CreateCall(FunctionType *FTy, Value *Callee, ArrayRef< Value * > Args=std::nullopt, const Twine &Name="", MDNode *FPMathTag=nullptr)
Definition: IRBuilder.h:2374
Value * CreateGEP(Type *Ty, Value *Ptr, ArrayRef< Value * > IdxList, const Twine &Name="", bool IsInBounds=false)
Definition: IRBuilder.h:1862
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:650
Value * CreateMul(Value *LHS, Value *RHS, const Twine &Name="", bool HasNUW=false, bool HasNSW=false)
Definition: IRBuilder.h:1352
This provides a uniform API for creating instructions and inserting them into a basic block: either a...
Definition: IRBuilder.h:2628
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:392
const Module * getModule() const
Return the module owning the function this instruction belongs to or nullptr it the function does not...
Definition: Instruction.cpp:71
bool hasMetadata() const
Return true if this instruction has any metadata attached to it.
Definition: Instruction.h:284
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:83
void setDebugLoc(DebugLoc Loc)
Set the debug location information for this instruction.
Definition: Instruction.h:389
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:279
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:950
static MDTuple * get(LLVMContext &Context, ArrayRef< Metadata * > MDs)
Definition: Metadata.h:1416
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.h:254
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:94
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:384
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:366
SmallPtrSet - This class implements a set which is optimized for holding SmallSize or less elements.
Definition: SmallPtrSet.h:451
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:374
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:806
bool isDriverKit() const
Is this an Apple DriverKit triple.
Definition: Triple.h:513
bool isOSNetBSD() const
Definition: Triple.h:536
bool isAndroid() const
Tests whether the target is Android.
Definition: Triple.h:725
bool isMIPS64() const
Tests whether the target is MIPS 64-bit (little and big endian).
Definition: Triple.h:897
ArchType getArch() const
Get the parsed architecture type of this triple.
Definition: Triple.h:355
bool isLoongArch64() const
Tests whether the target is 64-bit LoongArch.
Definition: Triple.h:886
EnvironmentType getEnvironment() const
Get the parsed environment type of this triple.
Definition: Triple.h:372
bool isMIPS32() const
Tests whether the target is MIPS 32-bit (little and big endian).
Definition: Triple.h:892
bool isOSWindows() const
Tests whether the OS is Windows.
Definition: Triple.h:584
@ DXContainer
Definition: Triple.h:283
@ UnknownObjectFormat
Definition: Triple.h:280
bool isARM() const
Tests whether the target is ARM (little and big endian).
Definition: Triple.h:811
bool isOSLinux() const
Tests whether the OS is Linux.
Definition: Triple.h:638
bool isAMDGPU() const
Definition: Triple.h:801
bool isMacOSX() const
Is this a Mac OS X triple.
Definition: Triple.h:485
bool isOSFreeBSD() const
Definition: Triple.h:544
bool isOSEmscripten() const
Tests whether the OS is Emscripten.
Definition: Triple.h:658
bool isWatchOS() const
Is this an Apple watchOS triple.
Definition: Triple.h:504
bool isiOS() const
Is this an iOS triple.
Definition: Triple.h:494
bool isPS() const
Tests whether the target is the PS4 or PS5 platform.
Definition: Triple.h:722
bool isOSFuchsia() const
Definition: Triple.h:548
Twine - A lightweight data structure for efficiently representing the concatenation of temporary valu...
Definition: Twine.h:81
The instances of the Type class are immutable: once they are created, they are never changed.
Definition: Type.h:45
PointerType * getPointerTo(unsigned AddrSpace=0) const
Return a pointer to the current type.
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:302
static IntegerType * getInt8Ty(LLVMContext &C)
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:394
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:535
StringRef getName() const
Return a constant reference to the value's name.
Definition: Value.cpp:309
void takeName(Value *V)
Transfer the name from V to this value.
Definition: Value.cpp:384
static VectorType * get(Type *ElementType, ElementCount EC)
This static method is the primary way to construct an VectorType.
Definition: Type.cpp:677
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:1021
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:1422
@ 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:705
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:440
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:1727
SmallVector< uint8_t, 64 > GetShadowBytesAfterScope(const SmallVectorImpl< ASanStackVariableDescription > &Vars, const ASanStackFrameLayout &Layout)
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,...
Op::Description Desc
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:264
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 SplitBlockAndInsertIfThenElse(Value *Cond, BasicBlock::iterator SplitBefore, Instruction **ThenTerm, Instruction **ElseTerm, MDNode *BranchWeights=nullptr, DomTreeUpdater *DTU=nullptr, LoopInfo *LI=nullptr)
SplitBlockAndInsertIfThenElse is similar to SplitBlockAndInsertIfThen, but also creates the ElseBlock...
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:156
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:749
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.