Bug Summary

File:lib/Transforms/Instrumentation/MemorySanitizer.cpp
Warning:line 2421, column 23
1st function call argument is an uninitialized value

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name MemorySanitizer.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-config-compatibility-mode=true -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn348900/build-llvm/lib/Transforms/Instrumentation -I /build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation -I /build/llvm-toolchain-snapshot-8~svn348900/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn348900/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-command-line-argument -Wno-unknown-warning-option -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn348900/build-llvm/lib/Transforms/Instrumentation -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-12-12-042652-12204-1 -x c++ /build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp -faddrsig
1//===- MemorySanitizer.cpp - detector of uninitialized reads --------------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10/// \file
11/// This file is a part of MemorySanitizer, a detector of uninitialized
12/// reads.
13///
14/// The algorithm of the tool is similar to Memcheck
15/// (http://goo.gl/QKbem). We associate a few shadow bits with every
16/// byte of the application memory, poison the shadow of the malloc-ed
17/// or alloca-ed memory, load the shadow bits on every memory read,
18/// propagate the shadow bits through some of the arithmetic
19/// instruction (including MOV), store the shadow bits on every memory
20/// write, report a bug on some other instructions (e.g. JMP) if the
21/// associated shadow is poisoned.
22///
23/// But there are differences too. The first and the major one:
24/// compiler instrumentation instead of binary instrumentation. This
25/// gives us much better register allocation, possible compiler
26/// optimizations and a fast start-up. But this brings the major issue
27/// as well: msan needs to see all program events, including system
28/// calls and reads/writes in system libraries, so we either need to
29/// compile *everything* with msan or use a binary translation
30/// component (e.g. DynamoRIO) to instrument pre-built libraries.
31/// Another difference from Memcheck is that we use 8 shadow bits per
32/// byte of application memory and use a direct shadow mapping. This
33/// greatly simplifies the instrumentation code and avoids races on
34/// shadow updates (Memcheck is single-threaded so races are not a
35/// concern there. Memcheck uses 2 shadow bits per byte with a slow
36/// path storage that uses 8 bits per byte).
37///
38/// The default value of shadow is 0, which means "clean" (not poisoned).
39///
40/// Every module initializer should call __msan_init to ensure that the
41/// shadow memory is ready. On error, __msan_warning is called. Since
42/// parameters and return values may be passed via registers, we have a
43/// specialized thread-local shadow for return values
44/// (__msan_retval_tls) and parameters (__msan_param_tls).
45///
46/// Origin tracking.
47///
48/// MemorySanitizer can track origins (allocation points) of all uninitialized
49/// values. This behavior is controlled with a flag (msan-track-origins) and is
50/// disabled by default.
51///
52/// Origins are 4-byte values created and interpreted by the runtime library.
53/// They are stored in a second shadow mapping, one 4-byte value for 4 bytes
54/// of application memory. Propagation of origins is basically a bunch of
55/// "select" instructions that pick the origin of a dirty argument, if an
56/// instruction has one.
57///
58/// Every 4 aligned, consecutive bytes of application memory have one origin
59/// value associated with them. If these bytes contain uninitialized data
60/// coming from 2 different allocations, the last store wins. Because of this,
61/// MemorySanitizer reports can show unrelated origins, but this is unlikely in
62/// practice.
63///
64/// Origins are meaningless for fully initialized values, so MemorySanitizer
65/// avoids storing origin to memory when a fully initialized value is stored.
66/// This way it avoids needless overwritting origin of the 4-byte region on
67/// a short (i.e. 1 byte) clean store, and it is also good for performance.
68///
69/// Atomic handling.
70///
71/// Ideally, every atomic store of application value should update the
72/// corresponding shadow location in an atomic way. Unfortunately, atomic store
73/// of two disjoint locations can not be done without severe slowdown.
74///
75/// Therefore, we implement an approximation that may err on the safe side.
76/// In this implementation, every atomically accessed location in the program
77/// may only change from (partially) uninitialized to fully initialized, but
78/// not the other way around. We load the shadow _after_ the application load,
79/// and we store the shadow _before_ the app store. Also, we always store clean
80/// shadow (if the application store is atomic). This way, if the store-load
81/// pair constitutes a happens-before arc, shadow store and load are correctly
82/// ordered such that the load will get either the value that was stored, or
83/// some later value (which is always clean).
84///
85/// This does not work very well with Compare-And-Swap (CAS) and
86/// Read-Modify-Write (RMW) operations. To follow the above logic, CAS and RMW
87/// must store the new shadow before the app operation, and load the shadow
88/// after the app operation. Computers don't work this way. Current
89/// implementation ignores the load aspect of CAS/RMW, always returning a clean
90/// value. It implements the store part as a simple atomic store by storing a
91/// clean shadow.
92///
93/// Instrumenting inline assembly.
94///
95/// For inline assembly code LLVM has little idea about which memory locations
96/// become initialized depending on the arguments. It can be possible to figure
97/// out which arguments are meant to point to inputs and outputs, but the
98/// actual semantics can be only visible at runtime. In the Linux kernel it's
99/// also possible that the arguments only indicate the offset for a base taken
100/// from a segment register, so it's dangerous to treat any asm() arguments as
101/// pointers. We take a conservative approach generating calls to
102/// __msan_instrument_asm_load(ptr, size) and
103/// __msan_instrument_asm_store(ptr, size)
104/// , which defer the memory checking/unpoisoning to the runtime library.
105/// The latter can perform more complex address checks to figure out whether
106/// it's safe to touch the shadow memory.
107/// Like with atomic operations, we call __msan_instrument_asm_store() before
108/// the assembly call, so that changes to the shadow memory will be seen by
109/// other threads together with main memory initialization.
110///
111/// KernelMemorySanitizer (KMSAN) implementation.
112///
113/// The major differences between KMSAN and MSan instrumentation are:
114/// - KMSAN always tracks the origins and implies msan-keep-going=true;
115/// - KMSAN allocates shadow and origin memory for each page separately, so
116/// there are no explicit accesses to shadow and origin in the
117/// instrumentation.
118/// Shadow and origin values for a particular X-byte memory location
119/// (X=1,2,4,8) are accessed through pointers obtained via the
120/// __msan_metadata_ptr_for_load_X(ptr)
121/// __msan_metadata_ptr_for_store_X(ptr)
122/// functions. The corresponding functions check that the X-byte accesses
123/// are possible and returns the pointers to shadow and origin memory.
124/// Arbitrary sized accesses are handled with:
125/// __msan_metadata_ptr_for_load_n(ptr, size)
126/// __msan_metadata_ptr_for_store_n(ptr, size);
127/// - TLS variables are stored in a single per-task struct. A call to a
128/// function __msan_get_context_state() returning a pointer to that struct
129/// is inserted into every instrumented function before the entry block;
130/// - __msan_warning() takes a 32-bit origin parameter;
131/// - local variables are poisoned with __msan_poison_alloca() upon function
132/// entry and unpoisoned with __msan_unpoison_alloca() before leaving the
133/// function;
134/// - the pass doesn't declare any global variables or add global constructors
135/// to the translation unit.
136///
137/// Also, KMSAN currently ignores uninitialized memory passed into inline asm
138/// calls, making sure we're on the safe side wrt. possible false positives.
139///
140/// KernelMemorySanitizer only supports X86_64 at the moment.
141///
142//===----------------------------------------------------------------------===//
143
144#include "llvm/ADT/APInt.h"
145#include "llvm/ADT/ArrayRef.h"
146#include "llvm/ADT/DepthFirstIterator.h"
147#include "llvm/ADT/SmallString.h"
148#include "llvm/ADT/SmallVector.h"
149#include "llvm/ADT/StringExtras.h"
150#include "llvm/ADT/StringRef.h"
151#include "llvm/ADT/Triple.h"
152#include "llvm/Analysis/TargetLibraryInfo.h"
153#include "llvm/Transforms/Utils/Local.h"
154#include "llvm/IR/Argument.h"
155#include "llvm/IR/Attributes.h"
156#include "llvm/IR/BasicBlock.h"
157#include "llvm/IR/CallSite.h"
158#include "llvm/IR/CallingConv.h"
159#include "llvm/IR/Constant.h"
160#include "llvm/IR/Constants.h"
161#include "llvm/IR/DataLayout.h"
162#include "llvm/IR/DerivedTypes.h"
163#include "llvm/IR/Function.h"
164#include "llvm/IR/GlobalValue.h"
165#include "llvm/IR/GlobalVariable.h"
166#include "llvm/IR/IRBuilder.h"
167#include "llvm/IR/InlineAsm.h"
168#include "llvm/IR/InstVisitor.h"
169#include "llvm/IR/InstrTypes.h"
170#include "llvm/IR/Instruction.h"
171#include "llvm/IR/Instructions.h"
172#include "llvm/IR/IntrinsicInst.h"
173#include "llvm/IR/Intrinsics.h"
174#include "llvm/IR/LLVMContext.h"
175#include "llvm/IR/MDBuilder.h"
176#include "llvm/IR/Module.h"
177#include "llvm/IR/Type.h"
178#include "llvm/IR/Value.h"
179#include "llvm/IR/ValueMap.h"
180#include "llvm/Pass.h"
181#include "llvm/Support/AtomicOrdering.h"
182#include "llvm/Support/Casting.h"
183#include "llvm/Support/CommandLine.h"
184#include "llvm/Support/Compiler.h"
185#include "llvm/Support/Debug.h"
186#include "llvm/Support/ErrorHandling.h"
187#include "llvm/Support/MathExtras.h"
188#include "llvm/Support/raw_ostream.h"
189#include "llvm/Transforms/Instrumentation.h"
190#include "llvm/Transforms/Utils/BasicBlockUtils.h"
191#include "llvm/Transforms/Utils/ModuleUtils.h"
192#include <algorithm>
193#include <cassert>
194#include <cstddef>
195#include <cstdint>
196#include <memory>
197#include <string>
198#include <tuple>
199
200using namespace llvm;
201
202#define DEBUG_TYPE"msan" "msan"
203
204static const unsigned kOriginSize = 4;
205static const unsigned kMinOriginAlignment = 4;
206static const unsigned kShadowTLSAlignment = 8;
207
208// These constants must be kept in sync with the ones in msan.h.
209static const unsigned kParamTLSSize = 800;
210static const unsigned kRetvalTLSSize = 800;
211
212// Accesses sizes are powers of two: 1, 2, 4, 8.
213static const size_t kNumberOfAccessSizes = 4;
214
215/// Track origins of uninitialized values.
216///
217/// Adds a section to MemorySanitizer report that points to the allocation
218/// (stack or heap) the uninitialized bits came from originally.
219static cl::opt<int> ClTrackOrigins("msan-track-origins",
220 cl::desc("Track origins (allocation sites) of poisoned memory"),
221 cl::Hidden, cl::init(0));
222
223static cl::opt<bool> ClKeepGoing("msan-keep-going",
224 cl::desc("keep going after reporting a UMR"),
225 cl::Hidden, cl::init(false));
226
227static cl::opt<bool> ClPoisonStack("msan-poison-stack",
228 cl::desc("poison uninitialized stack variables"),
229 cl::Hidden, cl::init(true));
230
231static cl::opt<bool> ClPoisonStackWithCall("msan-poison-stack-with-call",
232 cl::desc("poison uninitialized stack variables with a call"),
233 cl::Hidden, cl::init(false));
234
235static cl::opt<int> ClPoisonStackPattern("msan-poison-stack-pattern",
236 cl::desc("poison uninitialized stack variables with the given pattern"),
237 cl::Hidden, cl::init(0xff));
238
239static cl::opt<bool> ClPoisonUndef("msan-poison-undef",
240 cl::desc("poison undef temps"),
241 cl::Hidden, cl::init(true));
242
243static cl::opt<bool> ClHandleICmp("msan-handle-icmp",
244 cl::desc("propagate shadow through ICmpEQ and ICmpNE"),
245 cl::Hidden, cl::init(true));
246
247static cl::opt<bool> ClHandleICmpExact("msan-handle-icmp-exact",
248 cl::desc("exact handling of relational integer ICmp"),
249 cl::Hidden, cl::init(false));
250
251// When compiling the Linux kernel, we sometimes see false positives related to
252// MSan being unable to understand that inline assembly calls may initialize
253// local variables.
254// This flag makes the compiler conservatively unpoison every memory location
255// passed into an assembly call. Note that this may cause false positives.
256// Because it's impossible to figure out the array sizes, we can only unpoison
257// the first sizeof(type) bytes for each type* pointer.
258// The instrumentation is only enabled in KMSAN builds, and only if
259// -msan-handle-asm-conservative is on. This is done because we may want to
260// quickly disable assembly instrumentation when it breaks.
261static cl::opt<bool> ClHandleAsmConservative(
262 "msan-handle-asm-conservative",
263 cl::desc("conservative handling of inline assembly"), cl::Hidden,
264 cl::init(true));
265
266// This flag controls whether we check the shadow of the address
267// operand of load or store. Such bugs are very rare, since load from
268// a garbage address typically results in SEGV, but still happen
269// (e.g. only lower bits of address are garbage, or the access happens
270// early at program startup where malloc-ed memory is more likely to
271// be zeroed. As of 2012-08-28 this flag adds 20% slowdown.
272static cl::opt<bool> ClCheckAccessAddress("msan-check-access-address",
273 cl::desc("report accesses through a pointer which has poisoned shadow"),
274 cl::Hidden, cl::init(true));
275
276static cl::opt<bool> ClDumpStrictInstructions("msan-dump-strict-instructions",
277 cl::desc("print out instructions with default strict semantics"),
278 cl::Hidden, cl::init(false));
279
280static cl::opt<int> ClInstrumentationWithCallThreshold(
281 "msan-instrumentation-with-call-threshold",
282 cl::desc(
283 "If the function being instrumented requires more than "
284 "this number of checks and origin stores, use callbacks instead of "
285 "inline checks (-1 means never use callbacks)."),
286 cl::Hidden, cl::init(3500));
287
288static cl::opt<bool>
289 ClEnableKmsan("msan-kernel",
290 cl::desc("Enable KernelMemorySanitizer instrumentation"),
291 cl::Hidden, cl::init(false));
292
293// This is an experiment to enable handling of cases where shadow is a non-zero
294// compile-time constant. For some unexplainable reason they were silently
295// ignored in the instrumentation.
296static cl::opt<bool> ClCheckConstantShadow("msan-check-constant-shadow",
297 cl::desc("Insert checks for constant shadow values"),
298 cl::Hidden, cl::init(false));
299
300// This is off by default because of a bug in gold:
301// https://sourceware.org/bugzilla/show_bug.cgi?id=19002
302static cl::opt<bool> ClWithComdat("msan-with-comdat",
303 cl::desc("Place MSan constructors in comdat sections"),
304 cl::Hidden, cl::init(false));
305
306// These options allow to specify custom memory map parameters
307// See MemoryMapParams for details.
308static cl::opt<unsigned long long> ClAndMask("msan-and-mask",
309 cl::desc("Define custom MSan AndMask"),
310 cl::Hidden, cl::init(0));
311
312static cl::opt<unsigned long long> ClXorMask("msan-xor-mask",
313 cl::desc("Define custom MSan XorMask"),
314 cl::Hidden, cl::init(0));
315
316static cl::opt<unsigned long long> ClShadowBase("msan-shadow-base",
317 cl::desc("Define custom MSan ShadowBase"),
318 cl::Hidden, cl::init(0));
319
320static cl::opt<unsigned long long> ClOriginBase("msan-origin-base",
321 cl::desc("Define custom MSan OriginBase"),
322 cl::Hidden, cl::init(0));
323
324static const char *const kMsanModuleCtorName = "msan.module_ctor";
325static const char *const kMsanInitName = "__msan_init";
326
327namespace {
328
329// Memory map parameters used in application-to-shadow address calculation.
330// Offset = (Addr & ~AndMask) ^ XorMask
331// Shadow = ShadowBase + Offset
332// Origin = OriginBase + Offset
333struct MemoryMapParams {
334 uint64_t AndMask;
335 uint64_t XorMask;
336 uint64_t ShadowBase;
337 uint64_t OriginBase;
338};
339
340struct PlatformMemoryMapParams {
341 const MemoryMapParams *bits32;
342 const MemoryMapParams *bits64;
343};
344
345} // end anonymous namespace
346
347// i386 Linux
348static const MemoryMapParams Linux_I386_MemoryMapParams = {
349 0x000080000000, // AndMask
350 0, // XorMask (not used)
351 0, // ShadowBase (not used)
352 0x000040000000, // OriginBase
353};
354
355// x86_64 Linux
356static const MemoryMapParams Linux_X86_64_MemoryMapParams = {
357#ifdef MSAN_LINUX_X86_64_OLD_MAPPING
358 0x400000000000, // AndMask
359 0, // XorMask (not used)
360 0, // ShadowBase (not used)
361 0x200000000000, // OriginBase
362#else
363 0, // AndMask (not used)
364 0x500000000000, // XorMask
365 0, // ShadowBase (not used)
366 0x100000000000, // OriginBase
367#endif
368};
369
370// mips64 Linux
371static const MemoryMapParams Linux_MIPS64_MemoryMapParams = {
372 0, // AndMask (not used)
373 0x008000000000, // XorMask
374 0, // ShadowBase (not used)
375 0x002000000000, // OriginBase
376};
377
378// ppc64 Linux
379static const MemoryMapParams Linux_PowerPC64_MemoryMapParams = {
380 0xE00000000000, // AndMask
381 0x100000000000, // XorMask
382 0x080000000000, // ShadowBase
383 0x1C0000000000, // OriginBase
384};
385
386// aarch64 Linux
387static const MemoryMapParams Linux_AArch64_MemoryMapParams = {
388 0, // AndMask (not used)
389 0x06000000000, // XorMask
390 0, // ShadowBase (not used)
391 0x01000000000, // OriginBase
392};
393
394// i386 FreeBSD
395static const MemoryMapParams FreeBSD_I386_MemoryMapParams = {
396 0x000180000000, // AndMask
397 0x000040000000, // XorMask
398 0x000020000000, // ShadowBase
399 0x000700000000, // OriginBase
400};
401
402// x86_64 FreeBSD
403static const MemoryMapParams FreeBSD_X86_64_MemoryMapParams = {
404 0xc00000000000, // AndMask
405 0x200000000000, // XorMask
406 0x100000000000, // ShadowBase
407 0x380000000000, // OriginBase
408};
409
410// x86_64 NetBSD
411static const MemoryMapParams NetBSD_X86_64_MemoryMapParams = {
412 0, // AndMask
413 0x500000000000, // XorMask
414 0, // ShadowBase
415 0x100000000000, // OriginBase
416};
417
418static const PlatformMemoryMapParams Linux_X86_MemoryMapParams = {
419 &Linux_I386_MemoryMapParams,
420 &Linux_X86_64_MemoryMapParams,
421};
422
423static const PlatformMemoryMapParams Linux_MIPS_MemoryMapParams = {
424 nullptr,
425 &Linux_MIPS64_MemoryMapParams,
426};
427
428static const PlatformMemoryMapParams Linux_PowerPC_MemoryMapParams = {
429 nullptr,
430 &Linux_PowerPC64_MemoryMapParams,
431};
432
433static const PlatformMemoryMapParams Linux_ARM_MemoryMapParams = {
434 nullptr,
435 &Linux_AArch64_MemoryMapParams,
436};
437
438static const PlatformMemoryMapParams FreeBSD_X86_MemoryMapParams = {
439 &FreeBSD_I386_MemoryMapParams,
440 &FreeBSD_X86_64_MemoryMapParams,
441};
442
443static const PlatformMemoryMapParams NetBSD_X86_MemoryMapParams = {
444 nullptr,
445 &NetBSD_X86_64_MemoryMapParams,
446};
447
448namespace {
449
450/// An instrumentation pass implementing detection of uninitialized
451/// reads.
452///
453/// MemorySanitizer: instrument the code in module to find
454/// uninitialized reads.
455class MemorySanitizer : public FunctionPass {
456public:
457 // Pass identification, replacement for typeid.
458 static char ID;
459
460 MemorySanitizer(int TrackOrigins = 0, bool Recover = false,
461 bool EnableKmsan = false)
462 : FunctionPass(ID) {
463 this->CompileKernel =
464 ClEnableKmsan.getNumOccurrences() > 0 ? ClEnableKmsan : EnableKmsan;
465 if (ClTrackOrigins.getNumOccurrences() > 0)
466 this->TrackOrigins = ClTrackOrigins;
467 else
468 this->TrackOrigins = this->CompileKernel ? 2 : TrackOrigins;
469 this->Recover = ClKeepGoing.getNumOccurrences() > 0
470 ? ClKeepGoing
471 : (this->CompileKernel | Recover);
472 }
473 StringRef getPassName() const override { return "MemorySanitizer"; }
474
475 void getAnalysisUsage(AnalysisUsage &AU) const override {
476 AU.addRequired<TargetLibraryInfoWrapperPass>();
477 }
478
479 bool runOnFunction(Function &F) override;
480 bool doInitialization(Module &M) override;
481
482private:
483 friend struct MemorySanitizerVisitor;
484 friend struct VarArgAMD64Helper;
485 friend struct VarArgMIPS64Helper;
486 friend struct VarArgAArch64Helper;
487 friend struct VarArgPowerPC64Helper;
488
489 void initializeCallbacks(Module &M);
490 void createKernelApi(Module &M);
491 void createUserspaceApi(Module &M);
492
493 /// True if we're compiling the Linux kernel.
494 bool CompileKernel;
495
496 /// Track origins (allocation points) of uninitialized values.
497 int TrackOrigins;
498 bool Recover;
499
500 LLVMContext *C;
501 Type *IntptrTy;
502 Type *OriginTy;
503
504 // XxxTLS variables represent the per-thread state in MSan and per-task state
505 // in KMSAN.
506 // For the userspace these point to thread-local globals. In the kernel land
507 // they point to the members of a per-task struct obtained via a call to
508 // __msan_get_context_state().
509
510 /// Thread-local shadow storage for function parameters.
511 Value *ParamTLS;
512
513 /// Thread-local origin storage for function parameters.
514 Value *ParamOriginTLS;
515
516 /// Thread-local shadow storage for function return value.
517 Value *RetvalTLS;
518
519 /// Thread-local origin storage for function return value.
520 Value *RetvalOriginTLS;
521
522 /// Thread-local shadow storage for in-register va_arg function
523 /// parameters (x86_64-specific).
524 Value *VAArgTLS;
525
526 /// Thread-local shadow storage for in-register va_arg function
527 /// parameters (x86_64-specific).
528 Value *VAArgOriginTLS;
529
530 /// Thread-local shadow storage for va_arg overflow area
531 /// (x86_64-specific).
532 Value *VAArgOverflowSizeTLS;
533
534 /// Thread-local space used to pass origin value to the UMR reporting
535 /// function.
536 Value *OriginTLS;
537
538 /// Are the instrumentation callbacks set up?
539 bool CallbacksInitialized = false;
540
541 /// The run-time callback to print a warning.
542 Value *WarningFn;
543
544 // These arrays are indexed by log2(AccessSize).
545 Value *MaybeWarningFn[kNumberOfAccessSizes];
546 Value *MaybeStoreOriginFn[kNumberOfAccessSizes];
547
548 /// Run-time helper that generates a new origin value for a stack
549 /// allocation.
550 Value *MsanSetAllocaOrigin4Fn;
551
552 /// Run-time helper that poisons stack on function entry.
553 Value *MsanPoisonStackFn;
554
555 /// Run-time helper that records a store (or any event) of an
556 /// uninitialized value and returns an updated origin id encoding this info.
557 Value *MsanChainOriginFn;
558
559 /// MSan runtime replacements for memmove, memcpy and memset.
560 Value *MemmoveFn, *MemcpyFn, *MemsetFn;
561
562 /// KMSAN callback for task-local function argument shadow.
563 Value *MsanGetContextStateFn;
564
565 /// Functions for poisoning/unpoisoning local variables
566 Value *MsanPoisonAllocaFn, *MsanUnpoisonAllocaFn;
567
568 /// Each of the MsanMetadataPtrXxx functions returns a pair of shadow/origin
569 /// pointers.
570 Value *MsanMetadataPtrForLoadN, *MsanMetadataPtrForStoreN;
571 Value *MsanMetadataPtrForLoad_1_8[4];
572 Value *MsanMetadataPtrForStore_1_8[4];
573 Value *MsanInstrumentAsmStoreFn, *MsanInstrumentAsmLoadFn;
574
575 /// Helper to choose between different MsanMetadataPtrXxx().
576 Value *getKmsanShadowOriginAccessFn(bool isStore, int size);
577
578 /// Memory map parameters used in application-to-shadow calculation.
579 const MemoryMapParams *MapParams;
580
581 /// Custom memory map parameters used when -msan-shadow-base or
582 // -msan-origin-base is provided.
583 MemoryMapParams CustomMapParams;
584
585 MDNode *ColdCallWeights;
586
587 /// Branch weights for origin store.
588 MDNode *OriginStoreWeights;
589
590 /// An empty volatile inline asm that prevents callback merge.
591 InlineAsm *EmptyAsm;
592
593 Function *MsanCtorFunction;
594};
595
596} // end anonymous namespace
597
598char MemorySanitizer::ID = 0;
599
600INITIALIZE_PASS_BEGIN(static void *initializeMemorySanitizerPassOnce(PassRegistry &
Registry) {
601 MemorySanitizer, "msan",static void *initializeMemorySanitizerPassOnce(PassRegistry &
Registry) {
602 "MemorySanitizer: detects uninitialized reads.", false, false)static void *initializeMemorySanitizerPassOnce(PassRegistry &
Registry) {
603INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)initializeTargetLibraryInfoWrapperPassPass(Registry);
604INITIALIZE_PASS_END(PassInfo *PI = new PassInfo( "MemorySanitizer: detects uninitialized reads."
, "msan", &MemorySanitizer::ID, PassInfo::NormalCtor_t(callDefaultCtor
<MemorySanitizer>), false, false); Registry.registerPass
(*PI, true); return PI; } static llvm::once_flag InitializeMemorySanitizerPassFlag
; void llvm::initializeMemorySanitizerPass(PassRegistry &
Registry) { llvm::call_once(InitializeMemorySanitizerPassFlag
, initializeMemorySanitizerPassOnce, std::ref(Registry)); }
605 MemorySanitizer, "msan",PassInfo *PI = new PassInfo( "MemorySanitizer: detects uninitialized reads."
, "msan", &MemorySanitizer::ID, PassInfo::NormalCtor_t(callDefaultCtor
<MemorySanitizer>), false, false); Registry.registerPass
(*PI, true); return PI; } static llvm::once_flag InitializeMemorySanitizerPassFlag
; void llvm::initializeMemorySanitizerPass(PassRegistry &
Registry) { llvm::call_once(InitializeMemorySanitizerPassFlag
, initializeMemorySanitizerPassOnce, std::ref(Registry)); }
606 "MemorySanitizer: detects uninitialized reads.", false, false)PassInfo *PI = new PassInfo( "MemorySanitizer: detects uninitialized reads."
, "msan", &MemorySanitizer::ID, PassInfo::NormalCtor_t(callDefaultCtor
<MemorySanitizer>), false, false); Registry.registerPass
(*PI, true); return PI; } static llvm::once_flag InitializeMemorySanitizerPassFlag
; void llvm::initializeMemorySanitizerPass(PassRegistry &
Registry) { llvm::call_once(InitializeMemorySanitizerPassFlag
, initializeMemorySanitizerPassOnce, std::ref(Registry)); }
607
608FunctionPass *llvm::createMemorySanitizerPass(int TrackOrigins, bool Recover,
609 bool CompileKernel) {
610 return new MemorySanitizer(TrackOrigins, Recover, CompileKernel);
611}
612
613/// Create a non-const global initialized with the given string.
614///
615/// Creates a writable global for Str so that we can pass it to the
616/// run-time lib. Runtime uses first 4 bytes of the string to store the
617/// frame ID, so the string needs to be mutable.
618static GlobalVariable *createPrivateNonConstGlobalForString(Module &M,
619 StringRef Str) {
620 Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
621 return new GlobalVariable(M, StrConst->getType(), /*isConstant=*/false,
622 GlobalValue::PrivateLinkage, StrConst, "");
623}
624
625/// Create KMSAN API callbacks.
626void MemorySanitizer::createKernelApi(Module &M) {
627 IRBuilder<> IRB(*C);
628
629 // These will be initialized in insertKmsanPrologue().
630 RetvalTLS = nullptr;
631 RetvalOriginTLS = nullptr;
632 ParamTLS = nullptr;
633 ParamOriginTLS = nullptr;
634 VAArgTLS = nullptr;
635 VAArgOriginTLS = nullptr;
636 VAArgOverflowSizeTLS = nullptr;
637 // OriginTLS is unused in the kernel.
638 OriginTLS = nullptr;
639
640 // __msan_warning() in the kernel takes an origin.
641 WarningFn = M.getOrInsertFunction("__msan_warning", IRB.getVoidTy(),
642 IRB.getInt32Ty());
643 // Requests the per-task context state (kmsan_context_state*) from the
644 // runtime library.
645 MsanGetContextStateFn = M.getOrInsertFunction(
646 "__msan_get_context_state",
647 PointerType::get(
648 StructType::get(ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8),
649 ArrayType::get(IRB.getInt64Ty(), kRetvalTLSSize / 8),
650 ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8),
651 ArrayType::get(IRB.getInt64Ty(),
652 kParamTLSSize / 8), /* va_arg_origin */
653 IRB.getInt64Ty(),
654 ArrayType::get(OriginTy, kParamTLSSize / 4), OriginTy,
655 OriginTy),
656 0));
657
658 Type *RetTy = StructType::get(PointerType::get(IRB.getInt8Ty(), 0),
659 PointerType::get(IRB.getInt32Ty(), 0));
660
661 for (int ind = 0, size = 1; ind < 4; ind++, size <<= 1) {
662 std::string name_load =
663 "__msan_metadata_ptr_for_load_" + std::to_string(size);
664 std::string name_store =
665 "__msan_metadata_ptr_for_store_" + std::to_string(size);
666 MsanMetadataPtrForLoad_1_8[ind] = M.getOrInsertFunction(
667 name_load, RetTy, PointerType::get(IRB.getInt8Ty(), 0));
668 MsanMetadataPtrForStore_1_8[ind] = M.getOrInsertFunction(
669 name_store, RetTy, PointerType::get(IRB.getInt8Ty(), 0));
670 }
671
672 MsanMetadataPtrForLoadN = M.getOrInsertFunction(
673 "__msan_metadata_ptr_for_load_n", RetTy,
674 PointerType::get(IRB.getInt8Ty(), 0), IRB.getInt64Ty());
675 MsanMetadataPtrForStoreN = M.getOrInsertFunction(
676 "__msan_metadata_ptr_for_store_n", RetTy,
677 PointerType::get(IRB.getInt8Ty(), 0), IRB.getInt64Ty());
678
679 // Functions for poisoning and unpoisoning memory.
680 MsanPoisonAllocaFn =
681 M.getOrInsertFunction("__msan_poison_alloca", IRB.getVoidTy(),
682 IRB.getInt8PtrTy(), IntptrTy, IRB.getInt8PtrTy());
683 MsanUnpoisonAllocaFn = M.getOrInsertFunction(
684 "__msan_unpoison_alloca", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy);
685}
686
687/// Insert declarations for userspace-specific functions and globals.
688void MemorySanitizer::createUserspaceApi(Module &M) {
689 IRBuilder<> IRB(*C);
690 // Create the callback.
691 // FIXME: this function should have "Cold" calling conv,
692 // which is not yet implemented.
693 StringRef WarningFnName = Recover ? "__msan_warning"
694 : "__msan_warning_noreturn";
695 WarningFn = M.getOrInsertFunction(WarningFnName, IRB.getVoidTy());
696
697 // Create the global TLS variables.
698 RetvalTLS = new GlobalVariable(
699 M, ArrayType::get(IRB.getInt64Ty(), kRetvalTLSSize / 8), false,
700 GlobalVariable::ExternalLinkage, nullptr, "__msan_retval_tls", nullptr,
701 GlobalVariable::InitialExecTLSModel);
702
703 RetvalOriginTLS = new GlobalVariable(
704 M, OriginTy, false, GlobalVariable::ExternalLinkage, nullptr,
705 "__msan_retval_origin_tls", nullptr, GlobalVariable::InitialExecTLSModel);
706
707 ParamTLS = new GlobalVariable(
708 M, ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8), false,
709 GlobalVariable::ExternalLinkage, nullptr, "__msan_param_tls", nullptr,
710 GlobalVariable::InitialExecTLSModel);
711
712 ParamOriginTLS = new GlobalVariable(
713 M, ArrayType::get(OriginTy, kParamTLSSize / 4), false,
714 GlobalVariable::ExternalLinkage, nullptr, "__msan_param_origin_tls",
715 nullptr, GlobalVariable::InitialExecTLSModel);
716
717 VAArgTLS = new GlobalVariable(
718 M, ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8), false,
719 GlobalVariable::ExternalLinkage, nullptr, "__msan_va_arg_tls", nullptr,
720 GlobalVariable::InitialExecTLSModel);
721
722 VAArgOriginTLS = new GlobalVariable(
723 M, ArrayType::get(OriginTy, kParamTLSSize / 4), false,
724 GlobalVariable::ExternalLinkage, nullptr, "__msan_va_arg_origin_tls",
725 nullptr, GlobalVariable::InitialExecTLSModel);
726
727 VAArgOverflowSizeTLS = new GlobalVariable(
728 M, IRB.getInt64Ty(), false, GlobalVariable::ExternalLinkage, nullptr,
729 "__msan_va_arg_overflow_size_tls", nullptr,
730 GlobalVariable::InitialExecTLSModel);
731 OriginTLS = new GlobalVariable(
732 M, IRB.getInt32Ty(), false, GlobalVariable::ExternalLinkage, nullptr,
733 "__msan_origin_tls", nullptr, GlobalVariable::InitialExecTLSModel);
734
735 for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
736 AccessSizeIndex++) {
737 unsigned AccessSize = 1 << AccessSizeIndex;
738 std::string FunctionName = "__msan_maybe_warning_" + itostr(AccessSize);
739 MaybeWarningFn[AccessSizeIndex] = M.getOrInsertFunction(
740 FunctionName, IRB.getVoidTy(), IRB.getIntNTy(AccessSize * 8),
741 IRB.getInt32Ty());
742
743 FunctionName = "__msan_maybe_store_origin_" + itostr(AccessSize);
744 MaybeStoreOriginFn[AccessSizeIndex] = M.getOrInsertFunction(
745 FunctionName, IRB.getVoidTy(), IRB.getIntNTy(AccessSize * 8),
746 IRB.getInt8PtrTy(), IRB.getInt32Ty());
747 }
748
749 MsanSetAllocaOrigin4Fn = M.getOrInsertFunction(
750 "__msan_set_alloca_origin4", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy,
751 IRB.getInt8PtrTy(), IntptrTy);
752 MsanPoisonStackFn =
753 M.getOrInsertFunction("__msan_poison_stack", IRB.getVoidTy(),
754 IRB.getInt8PtrTy(), IntptrTy);
755}
756
757/// Insert extern declaration of runtime-provided functions and globals.
758void MemorySanitizer::initializeCallbacks(Module &M) {
759 // Only do this once.
760 if (CallbacksInitialized)
761 return;
762
763 IRBuilder<> IRB(*C);
764 // Initialize callbacks that are common for kernel and userspace
765 // instrumentation.
766 MsanChainOriginFn = M.getOrInsertFunction(
767 "__msan_chain_origin", IRB.getInt32Ty(), IRB.getInt32Ty());
768 MemmoveFn = M.getOrInsertFunction(
769 "__msan_memmove", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
770 IRB.getInt8PtrTy(), IntptrTy);
771 MemcpyFn = M.getOrInsertFunction(
772 "__msan_memcpy", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
773 IntptrTy);
774 MemsetFn = M.getOrInsertFunction(
775 "__msan_memset", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IRB.getInt32Ty(),
776 IntptrTy);
777 // We insert an empty inline asm after __msan_report* to avoid callback merge.
778 EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
779 StringRef(""), StringRef(""),
780 /*hasSideEffects=*/true);
781
782 MsanInstrumentAsmLoadFn =
783 M.getOrInsertFunction("__msan_instrument_asm_load", IRB.getVoidTy(),
784 PointerType::get(IRB.getInt8Ty(), 0), IntptrTy);
785 MsanInstrumentAsmStoreFn =
786 M.getOrInsertFunction("__msan_instrument_asm_store", IRB.getVoidTy(),
787 PointerType::get(IRB.getInt8Ty(), 0), IntptrTy);
788
789 if (CompileKernel) {
790 createKernelApi(M);
791 } else {
792 createUserspaceApi(M);
793 }
794 CallbacksInitialized = true;
795}
796
797Value *MemorySanitizer::getKmsanShadowOriginAccessFn(bool isStore, int size) {
798 Value **Fns =
799 isStore ? MsanMetadataPtrForStore_1_8 : MsanMetadataPtrForLoad_1_8;
800 switch (size) {
801 case 1:
802 return Fns[0];
803 case 2:
804 return Fns[1];
805 case 4:
806 return Fns[2];
807 case 8:
808 return Fns[3];
809 default:
810 return nullptr;
811 }
812}
813
814/// Module-level initialization.
815///
816/// inserts a call to __msan_init to the module's constructor list.
817bool MemorySanitizer::doInitialization(Module &M) {
818 auto &DL = M.getDataLayout();
819
820 bool ShadowPassed = ClShadowBase.getNumOccurrences() > 0;
821 bool OriginPassed = ClOriginBase.getNumOccurrences() > 0;
822 // Check the overrides first
823 if (ShadowPassed || OriginPassed) {
824 CustomMapParams.AndMask = ClAndMask;
825 CustomMapParams.XorMask = ClXorMask;
826 CustomMapParams.ShadowBase = ClShadowBase;
827 CustomMapParams.OriginBase = ClOriginBase;
828 MapParams = &CustomMapParams;
829 } else {
830 Triple TargetTriple(M.getTargetTriple());
831 switch (TargetTriple.getOS()) {
832 case Triple::FreeBSD:
833 switch (TargetTriple.getArch()) {
834 case Triple::x86_64:
835 MapParams = FreeBSD_X86_MemoryMapParams.bits64;
836 break;
837 case Triple::x86:
838 MapParams = FreeBSD_X86_MemoryMapParams.bits32;
839 break;
840 default:
841 report_fatal_error("unsupported architecture");
842 }
843 break;
844 case Triple::NetBSD:
845 switch (TargetTriple.getArch()) {
846 case Triple::x86_64:
847 MapParams = NetBSD_X86_MemoryMapParams.bits64;
848 break;
849 default:
850 report_fatal_error("unsupported architecture");
851 }
852 break;
853 case Triple::Linux:
854 switch (TargetTriple.getArch()) {
855 case Triple::x86_64:
856 MapParams = Linux_X86_MemoryMapParams.bits64;
857 break;
858 case Triple::x86:
859 MapParams = Linux_X86_MemoryMapParams.bits32;
860 break;
861 case Triple::mips64:
862 case Triple::mips64el:
863 MapParams = Linux_MIPS_MemoryMapParams.bits64;
864 break;
865 case Triple::ppc64:
866 case Triple::ppc64le:
867 MapParams = Linux_PowerPC_MemoryMapParams.bits64;
868 break;
869 case Triple::aarch64:
870 case Triple::aarch64_be:
871 MapParams = Linux_ARM_MemoryMapParams.bits64;
872 break;
873 default:
874 report_fatal_error("unsupported architecture");
875 }
876 break;
877 default:
878 report_fatal_error("unsupported operating system");
879 }
880 }
881
882 C = &(M.getContext());
883 IRBuilder<> IRB(*C);
884 IntptrTy = IRB.getIntPtrTy(DL);
885 OriginTy = IRB.getInt32Ty();
886
887 ColdCallWeights = MDBuilder(*C).createBranchWeights(1, 1000);
888 OriginStoreWeights = MDBuilder(*C).createBranchWeights(1, 1000);
889
890 if (!CompileKernel) {
891 std::tie(MsanCtorFunction, std::ignore) =
892 createSanitizerCtorAndInitFunctions(M, kMsanModuleCtorName,
893 kMsanInitName,
894 /*InitArgTypes=*/{},
895 /*InitArgs=*/{});
896 if (ClWithComdat) {
897 Comdat *MsanCtorComdat = M.getOrInsertComdat(kMsanModuleCtorName);
898 MsanCtorFunction->setComdat(MsanCtorComdat);
899 appendToGlobalCtors(M, MsanCtorFunction, 0, MsanCtorFunction);
900 } else {
901 appendToGlobalCtors(M, MsanCtorFunction, 0);
902 }
903
904 if (TrackOrigins)
905 new GlobalVariable(M, IRB.getInt32Ty(), true, GlobalValue::WeakODRLinkage,
906 IRB.getInt32(TrackOrigins), "__msan_track_origins");
907
908 if (Recover)
909 new GlobalVariable(M, IRB.getInt32Ty(), true, GlobalValue::WeakODRLinkage,
910 IRB.getInt32(Recover), "__msan_keep_going");
911 }
912 return true;
913}
914
915namespace {
916
917/// A helper class that handles instrumentation of VarArg
918/// functions on a particular platform.
919///
920/// Implementations are expected to insert the instrumentation
921/// necessary to propagate argument shadow through VarArg function
922/// calls. Visit* methods are called during an InstVisitor pass over
923/// the function, and should avoid creating new basic blocks. A new
924/// instance of this class is created for each instrumented function.
925struct VarArgHelper {
926 virtual ~VarArgHelper() = default;
927
928 /// Visit a CallSite.
929 virtual void visitCallSite(CallSite &CS, IRBuilder<> &IRB) = 0;
930
931 /// Visit a va_start call.
932 virtual void visitVAStartInst(VAStartInst &I) = 0;
933
934 /// Visit a va_copy call.
935 virtual void visitVACopyInst(VACopyInst &I) = 0;
936
937 /// Finalize function instrumentation.
938 ///
939 /// This method is called after visiting all interesting (see above)
940 /// instructions in a function.
941 virtual void finalizeInstrumentation() = 0;
942};
943
944struct MemorySanitizerVisitor;
945
946} // end anonymous namespace
947
948static VarArgHelper *CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
949 MemorySanitizerVisitor &Visitor);
950
951static unsigned TypeSizeToSizeIndex(unsigned TypeSize) {
952 if (TypeSize <= 8) return 0;
953 return Log2_32_Ceil((TypeSize + 7) / 8);
954}
955
956namespace {
957
958/// This class does all the work for a given function. Store and Load
959/// instructions store and load corresponding shadow and origin
960/// values. Most instructions propagate shadow from arguments to their
961/// return values. Certain instructions (most importantly, BranchInst)
962/// test their argument shadow and print reports (with a runtime call) if it's
963/// non-zero.
964struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
965 Function &F;
966 MemorySanitizer &MS;
967 SmallVector<PHINode *, 16> ShadowPHINodes, OriginPHINodes;
968 ValueMap<Value*, Value*> ShadowMap, OriginMap;
969 std::unique_ptr<VarArgHelper> VAHelper;
970 const TargetLibraryInfo *TLI;
971 BasicBlock *ActualFnStart;
972
973 // The following flags disable parts of MSan instrumentation based on
974 // blacklist contents and command-line options.
975 bool InsertChecks;
976 bool PropagateShadow;
977 bool PoisonStack;
978 bool PoisonUndef;
979 bool CheckReturnValue;
980
981 struct ShadowOriginAndInsertPoint {
982 Value *Shadow;
983 Value *Origin;
984 Instruction *OrigIns;
985
986 ShadowOriginAndInsertPoint(Value *S, Value *O, Instruction *I)
987 : Shadow(S), Origin(O), OrigIns(I) {}
988 };
989 SmallVector<ShadowOriginAndInsertPoint, 16> InstrumentationList;
990 SmallVector<StoreInst *, 16> StoreList;
991
992 MemorySanitizerVisitor(Function &F, MemorySanitizer &MS)
993 : F(F), MS(MS), VAHelper(CreateVarArgHelper(F, MS, *this)) {
994 bool SanitizeFunction = F.hasFnAttribute(Attribute::SanitizeMemory);
995 InsertChecks = SanitizeFunction;
996 PropagateShadow = SanitizeFunction;
997 PoisonStack = SanitizeFunction && ClPoisonStack;
998 PoisonUndef = SanitizeFunction && ClPoisonUndef;
999 // FIXME: Consider using SpecialCaseList to specify a list of functions that
1000 // must always return fully initialized values. For now, we hardcode "main".
1001 CheckReturnValue = SanitizeFunction && (F.getName() == "main");
1002 TLI = &MS.getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
1003
1004 MS.initializeCallbacks(*F.getParent());
1005 if (MS.CompileKernel)
1006 ActualFnStart = insertKmsanPrologue(F);
1007 else
1008 ActualFnStart = &F.getEntryBlock();
1009
1010 LLVM_DEBUG(if (!InsertChecks) dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { if (!InsertChecks) dbgs() << "MemorySanitizer is not inserting checks into '"
<< F.getName() << "'\n"; } } while (false)
1011 << "MemorySanitizer is not inserting checks into '"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { if (!InsertChecks) dbgs() << "MemorySanitizer is not inserting checks into '"
<< F.getName() << "'\n"; } } while (false)
1012 << F.getName() << "'\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { if (!InsertChecks) dbgs() << "MemorySanitizer is not inserting checks into '"
<< F.getName() << "'\n"; } } while (false)
;
1013 }
1014
1015 Value *updateOrigin(Value *V, IRBuilder<> &IRB) {
1016 if (MS.TrackOrigins <= 1) return V;
1017 return IRB.CreateCall(MS.MsanChainOriginFn, V);
1018 }
1019
1020 Value *originToIntptr(IRBuilder<> &IRB, Value *Origin) {
1021 const DataLayout &DL = F.getParent()->getDataLayout();
1022 unsigned IntptrSize = DL.getTypeStoreSize(MS.IntptrTy);
1023 if (IntptrSize == kOriginSize) return Origin;
1024 assert(IntptrSize == kOriginSize * 2)((IntptrSize == kOriginSize * 2) ? static_cast<void> (0
) : __assert_fail ("IntptrSize == kOriginSize * 2", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1024, __PRETTY_FUNCTION__))
;
1025 Origin = IRB.CreateIntCast(Origin, MS.IntptrTy, /* isSigned */ false);
1026 return IRB.CreateOr(Origin, IRB.CreateShl(Origin, kOriginSize * 8));
1027 }
1028
1029 /// Fill memory range with the given origin value.
1030 void paintOrigin(IRBuilder<> &IRB, Value *Origin, Value *OriginPtr,
1031 unsigned Size, unsigned Alignment) {
1032 const DataLayout &DL = F.getParent()->getDataLayout();
1033 unsigned IntptrAlignment = DL.getABITypeAlignment(MS.IntptrTy);
1034 unsigned IntptrSize = DL.getTypeStoreSize(MS.IntptrTy);
1035 assert(IntptrAlignment >= kMinOriginAlignment)((IntptrAlignment >= kMinOriginAlignment) ? static_cast<
void> (0) : __assert_fail ("IntptrAlignment >= kMinOriginAlignment"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1035, __PRETTY_FUNCTION__))
;
1036 assert(IntptrSize >= kOriginSize)((IntptrSize >= kOriginSize) ? static_cast<void> (0)
: __assert_fail ("IntptrSize >= kOriginSize", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1036, __PRETTY_FUNCTION__))
;
1037
1038 unsigned Ofs = 0;
1039 unsigned CurrentAlignment = Alignment;
1040 if (Alignment >= IntptrAlignment && IntptrSize > kOriginSize) {
1041 Value *IntptrOrigin = originToIntptr(IRB, Origin);
1042 Value *IntptrOriginPtr =
1043 IRB.CreatePointerCast(OriginPtr, PointerType::get(MS.IntptrTy, 0));
1044 for (unsigned i = 0; i < Size / IntptrSize; ++i) {
1045 Value *Ptr = i ? IRB.CreateConstGEP1_32(MS.IntptrTy, IntptrOriginPtr, i)
1046 : IntptrOriginPtr;
1047 IRB.CreateAlignedStore(IntptrOrigin, Ptr, CurrentAlignment);
1048 Ofs += IntptrSize / kOriginSize;
1049 CurrentAlignment = IntptrAlignment;
1050 }
1051 }
1052
1053 for (unsigned i = Ofs; i < (Size + kOriginSize - 1) / kOriginSize; ++i) {
1054 Value *GEP =
1055 i ? IRB.CreateConstGEP1_32(nullptr, OriginPtr, i) : OriginPtr;
1056 IRB.CreateAlignedStore(Origin, GEP, CurrentAlignment);
1057 CurrentAlignment = kMinOriginAlignment;
1058 }
1059 }
1060
1061 void storeOrigin(IRBuilder<> &IRB, Value *Addr, Value *Shadow, Value *Origin,
1062 Value *OriginPtr, unsigned Alignment, bool AsCall) {
1063 const DataLayout &DL = F.getParent()->getDataLayout();
1064 unsigned OriginAlignment = std::max(kMinOriginAlignment, Alignment);
1065 unsigned StoreSize = DL.getTypeStoreSize(Shadow->getType());
1066 if (Shadow->getType()->isAggregateType()) {
1067 paintOrigin(IRB, updateOrigin(Origin, IRB), OriginPtr, StoreSize,
1068 OriginAlignment);
1069 } else {
1070 Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
1071 Constant *ConstantShadow = dyn_cast_or_null<Constant>(ConvertedShadow);
1072 if (ConstantShadow) {
1073 if (ClCheckConstantShadow && !ConstantShadow->isZeroValue())
1074 paintOrigin(IRB, updateOrigin(Origin, IRB), OriginPtr, StoreSize,
1075 OriginAlignment);
1076 return;
1077 }
1078
1079 unsigned TypeSizeInBits =
1080 DL.getTypeSizeInBits(ConvertedShadow->getType());
1081 unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits);
1082 if (AsCall && SizeIndex < kNumberOfAccessSizes && !MS.CompileKernel) {
1083 Value *Fn = MS.MaybeStoreOriginFn[SizeIndex];
1084 Value *ConvertedShadow2 = IRB.CreateZExt(
1085 ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex)));
1086 IRB.CreateCall(Fn, {ConvertedShadow2,
1087 IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()),
1088 Origin});
1089 } else {
1090 Value *Cmp = IRB.CreateICmpNE(
1091 ConvertedShadow, getCleanShadow(ConvertedShadow), "_mscmp");
1092 Instruction *CheckTerm = SplitBlockAndInsertIfThen(
1093 Cmp, &*IRB.GetInsertPoint(), false, MS.OriginStoreWeights);
1094 IRBuilder<> IRBNew(CheckTerm);
1095 paintOrigin(IRBNew, updateOrigin(Origin, IRBNew), OriginPtr, StoreSize,
1096 OriginAlignment);
1097 }
1098 }
1099 }
1100
1101 void materializeStores(bool InstrumentWithCalls) {
1102 for (StoreInst *SI : StoreList) {
1103 IRBuilder<> IRB(SI);
1104 Value *Val = SI->getValueOperand();
1105 Value *Addr = SI->getPointerOperand();
1106 Value *Shadow = SI->isAtomic() ? getCleanShadow(Val) : getShadow(Val);
1107 Value *ShadowPtr, *OriginPtr;
1108 Type *ShadowTy = Shadow->getType();
1109 unsigned Alignment = SI->getAlignment();
1110 unsigned OriginAlignment = std::max(kMinOriginAlignment, Alignment);
1111 std::tie(ShadowPtr, OriginPtr) =
1112 getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ true);
1113
1114 StoreInst *NewSI = IRB.CreateAlignedStore(Shadow, ShadowPtr, Alignment);
1115 LLVM_DEBUG(dbgs() << " STORE: " << *NewSI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " STORE: " << *NewSI <<
"\n"; } } while (false)
;
1116 (void)NewSI;
1117
1118 if (SI->isAtomic())
1119 SI->setOrdering(addReleaseOrdering(SI->getOrdering()));
1120
1121 if (MS.TrackOrigins && !SI->isAtomic())
1122 storeOrigin(IRB, Addr, Shadow, getOrigin(Val), OriginPtr,
1123 OriginAlignment, InstrumentWithCalls);
1124 }
1125 }
1126
1127 /// Helper function to insert a warning at IRB's current insert point.
1128 void insertWarningFn(IRBuilder<> &IRB, Value *Origin) {
1129 if (!Origin)
1130 Origin = (Value *)IRB.getInt32(0);
1131 if (MS.CompileKernel) {
1132 IRB.CreateCall(MS.WarningFn, Origin);
1133 } else {
1134 if (MS.TrackOrigins) {
1135 IRB.CreateStore(Origin, MS.OriginTLS);
1136 }
1137 IRB.CreateCall(MS.WarningFn, {});
1138 }
1139 IRB.CreateCall(MS.EmptyAsm, {});
1140 // FIXME: Insert UnreachableInst if !MS.Recover?
1141 // This may invalidate some of the following checks and needs to be done
1142 // at the very end.
1143 }
1144
1145 void materializeOneCheck(Instruction *OrigIns, Value *Shadow, Value *Origin,
1146 bool AsCall) {
1147 IRBuilder<> IRB(OrigIns);
1148 LLVM_DEBUG(dbgs() << " SHAD0 : " << *Shadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " SHAD0 : " << *Shadow <<
"\n"; } } while (false)
;
1149 Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB);
1150 LLVM_DEBUG(dbgs() << " SHAD1 : " << *ConvertedShadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " SHAD1 : " << *ConvertedShadow
<< "\n"; } } while (false)
;
1151
1152 Constant *ConstantShadow = dyn_cast_or_null<Constant>(ConvertedShadow);
1153 if (ConstantShadow) {
1154 if (ClCheckConstantShadow && !ConstantShadow->isZeroValue()) {
1155 insertWarningFn(IRB, Origin);
1156 }
1157 return;
1158 }
1159
1160 const DataLayout &DL = OrigIns->getModule()->getDataLayout();
1161
1162 unsigned TypeSizeInBits = DL.getTypeSizeInBits(ConvertedShadow->getType());
1163 unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits);
1164 if (AsCall && SizeIndex < kNumberOfAccessSizes && !MS.CompileKernel) {
1165 Value *Fn = MS.MaybeWarningFn[SizeIndex];
1166 Value *ConvertedShadow2 =
1167 IRB.CreateZExt(ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex)));
1168 IRB.CreateCall(Fn, {ConvertedShadow2, MS.TrackOrigins && Origin
1169 ? Origin
1170 : (Value *)IRB.getInt32(0)});
1171 } else {
1172 Value *Cmp = IRB.CreateICmpNE(ConvertedShadow,
1173 getCleanShadow(ConvertedShadow), "_mscmp");
1174 Instruction *CheckTerm = SplitBlockAndInsertIfThen(
1175 Cmp, OrigIns,
1176 /* Unreachable */ !MS.Recover, MS.ColdCallWeights);
1177
1178 IRB.SetInsertPoint(CheckTerm);
1179 insertWarningFn(IRB, Origin);
1180 LLVM_DEBUG(dbgs() << " CHECK: " << *Cmp << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " CHECK: " << *Cmp <<
"\n"; } } while (false)
;
1181 }
1182 }
1183
1184 void materializeChecks(bool InstrumentWithCalls) {
1185 for (const auto &ShadowData : InstrumentationList) {
1186 Instruction *OrigIns = ShadowData.OrigIns;
1187 Value *Shadow = ShadowData.Shadow;
1188 Value *Origin = ShadowData.Origin;
1189 materializeOneCheck(OrigIns, Shadow, Origin, InstrumentWithCalls);
1190 }
1191 LLVM_DEBUG(dbgs() << "DONE:\n" << F)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << "DONE:\n" << F; } } while (
false)
;
1192 }
1193
1194 BasicBlock *insertKmsanPrologue(Function &F) {
1195 BasicBlock *ret =
1196 SplitBlock(&F.getEntryBlock(), F.getEntryBlock().getFirstNonPHI());
1197 IRBuilder<> IRB(F.getEntryBlock().getFirstNonPHI());
1198 Value *ContextState = IRB.CreateCall(MS.MsanGetContextStateFn, {});
1199 Constant *Zero = IRB.getInt32(0);
1200 MS.ParamTLS =
1201 IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(0)}, "param_shadow");
1202 MS.RetvalTLS =
1203 IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(1)}, "retval_shadow");
1204 MS.VAArgTLS =
1205 IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(2)}, "va_arg_shadow");
1206 MS.VAArgOriginTLS =
1207 IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(3)}, "va_arg_origin");
1208 MS.VAArgOverflowSizeTLS = IRB.CreateGEP(
1209 ContextState, {Zero, IRB.getInt32(4)}, "va_arg_overflow_size");
1210 MS.ParamOriginTLS =
1211 IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(5)}, "param_origin");
1212 MS.RetvalOriginTLS =
1213 IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(6)}, "retval_origin");
1214 return ret;
1215 }
1216
1217 /// Add MemorySanitizer instrumentation to a function.
1218 bool runOnFunction() {
1219 // In the presence of unreachable blocks, we may see Phi nodes with
1220 // incoming nodes from such blocks. Since InstVisitor skips unreachable
1221 // blocks, such nodes will not have any shadow value associated with them.
1222 // It's easier to remove unreachable blocks than deal with missing shadow.
1223 removeUnreachableBlocks(F);
1224
1225 // Iterate all BBs in depth-first order and create shadow instructions
1226 // for all instructions (where applicable).
1227 // For PHI nodes we create dummy shadow PHIs which will be finalized later.
1228 for (BasicBlock *BB : depth_first(ActualFnStart))
1229 visit(*BB);
1230
1231 // Finalize PHI nodes.
1232 for (PHINode *PN : ShadowPHINodes) {
1233 PHINode *PNS = cast<PHINode>(getShadow(PN));
1234 PHINode *PNO = MS.TrackOrigins ? cast<PHINode>(getOrigin(PN)) : nullptr;
1235 size_t NumValues = PN->getNumIncomingValues();
1236 for (size_t v = 0; v < NumValues; v++) {
1237 PNS->addIncoming(getShadow(PN, v), PN->getIncomingBlock(v));
1238 if (PNO) PNO->addIncoming(getOrigin(PN, v), PN->getIncomingBlock(v));
1239 }
1240 }
1241
1242 VAHelper->finalizeInstrumentation();
1243
1244 bool InstrumentWithCalls = ClInstrumentationWithCallThreshold >= 0 &&
1245 InstrumentationList.size() + StoreList.size() >
1246 (unsigned)ClInstrumentationWithCallThreshold;
1247
1248 // Insert shadow value checks.
1249 materializeChecks(InstrumentWithCalls);
1250
1251 // Delayed instrumentation of StoreInst.
1252 // This may not add new address checks.
1253 materializeStores(InstrumentWithCalls);
1254
1255 return true;
1256 }
1257
1258 /// Compute the shadow type that corresponds to a given Value.
1259 Type *getShadowTy(Value *V) {
1260 return getShadowTy(V->getType());
1261 }
1262
1263 /// Compute the shadow type that corresponds to a given Type.
1264 Type *getShadowTy(Type *OrigTy) {
1265 if (!OrigTy->isSized()) {
1266 return nullptr;
1267 }
1268 // For integer type, shadow is the same as the original type.
1269 // This may return weird-sized types like i1.
1270 if (IntegerType *IT = dyn_cast<IntegerType>(OrigTy))
1271 return IT;
1272 const DataLayout &DL = F.getParent()->getDataLayout();
1273 if (VectorType *VT = dyn_cast<VectorType>(OrigTy)) {
1274 uint32_t EltSize = DL.getTypeSizeInBits(VT->getElementType());
1275 return VectorType::get(IntegerType::get(*MS.C, EltSize),
1276 VT->getNumElements());
1277 }
1278 if (ArrayType *AT = dyn_cast<ArrayType>(OrigTy)) {
1279 return ArrayType::get(getShadowTy(AT->getElementType()),
1280 AT->getNumElements());
1281 }
1282 if (StructType *ST = dyn_cast<StructType>(OrigTy)) {
1283 SmallVector<Type*, 4> Elements;
1284 for (unsigned i = 0, n = ST->getNumElements(); i < n; i++)
1285 Elements.push_back(getShadowTy(ST->getElementType(i)));
1286 StructType *Res = StructType::get(*MS.C, Elements, ST->isPacked());
1287 LLVM_DEBUG(dbgs() << "getShadowTy: " << *ST << " ===> " << *Res << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << "getShadowTy: " << *ST <<
" ===> " << *Res << "\n"; } } while (false)
;
1288 return Res;
1289 }
1290 uint32_t TypeSize = DL.getTypeSizeInBits(OrigTy);
1291 return IntegerType::get(*MS.C, TypeSize);
1292 }
1293
1294 /// Flatten a vector type.
1295 Type *getShadowTyNoVec(Type *ty) {
1296 if (VectorType *vt = dyn_cast<VectorType>(ty))
1297 return IntegerType::get(*MS.C, vt->getBitWidth());
1298 return ty;
1299 }
1300
1301 /// Convert a shadow value to it's flattened variant.
1302 Value *convertToShadowTyNoVec(Value *V, IRBuilder<> &IRB) {
1303 Type *Ty = V->getType();
1304 Type *NoVecTy = getShadowTyNoVec(Ty);
1305 if (Ty == NoVecTy) return V;
1306 return IRB.CreateBitCast(V, NoVecTy);
1307 }
1308
1309 /// Compute the integer shadow offset that corresponds to a given
1310 /// application address.
1311 ///
1312 /// Offset = (Addr & ~AndMask) ^ XorMask
1313 Value *getShadowPtrOffset(Value *Addr, IRBuilder<> &IRB) {
1314 Value *OffsetLong = IRB.CreatePointerCast(Addr, MS.IntptrTy);
1315
1316 uint64_t AndMask = MS.MapParams->AndMask;
1317 if (AndMask)
1318 OffsetLong =
1319 IRB.CreateAnd(OffsetLong, ConstantInt::get(MS.IntptrTy, ~AndMask));
1320
1321 uint64_t XorMask = MS.MapParams->XorMask;
1322 if (XorMask)
1323 OffsetLong =
1324 IRB.CreateXor(OffsetLong, ConstantInt::get(MS.IntptrTy, XorMask));
1325 return OffsetLong;
1326 }
1327
1328 /// Compute the shadow and origin addresses corresponding to a given
1329 /// application address.
1330 ///
1331 /// Shadow = ShadowBase + Offset
1332 /// Origin = (OriginBase + Offset) & ~3ULL
1333 std::pair<Value *, Value *> getShadowOriginPtrUserspace(Value *Addr,
1334 IRBuilder<> &IRB,
1335 Type *ShadowTy,
1336 unsigned Alignment) {
1337 Value *ShadowOffset = getShadowPtrOffset(Addr, IRB);
1338 Value *ShadowLong = ShadowOffset;
1339 uint64_t ShadowBase = MS.MapParams->ShadowBase;
1340 if (ShadowBase != 0) {
1341 ShadowLong =
1342 IRB.CreateAdd(ShadowLong,
1343 ConstantInt::get(MS.IntptrTy, ShadowBase));
1344 }
1345 Value *ShadowPtr =
1346 IRB.CreateIntToPtr(ShadowLong, PointerType::get(ShadowTy, 0));
1347 Value *OriginPtr = nullptr;
1348 if (MS.TrackOrigins) {
1349 Value *OriginLong = ShadowOffset;
1350 uint64_t OriginBase = MS.MapParams->OriginBase;
1351 if (OriginBase != 0)
1352 OriginLong = IRB.CreateAdd(OriginLong,
1353 ConstantInt::get(MS.IntptrTy, OriginBase));
1354 if (Alignment < kMinOriginAlignment) {
1355 uint64_t Mask = kMinOriginAlignment - 1;
1356 OriginLong =
1357 IRB.CreateAnd(OriginLong, ConstantInt::get(MS.IntptrTy, ~Mask));
1358 }
1359 OriginPtr =
1360 IRB.CreateIntToPtr(OriginLong, PointerType::get(IRB.getInt32Ty(), 0));
1361 }
1362 return std::make_pair(ShadowPtr, OriginPtr);
1363 }
1364
1365 std::pair<Value *, Value *>
1366 getShadowOriginPtrKernel(Value *Addr, IRBuilder<> &IRB, Type *ShadowTy,
1367 unsigned Alignment, bool isStore) {
1368 Value *ShadowOriginPtrs;
1369 const DataLayout &DL = F.getParent()->getDataLayout();
1370 int Size = DL.getTypeStoreSize(ShadowTy);
1371
1372 Value *Getter = MS.getKmsanShadowOriginAccessFn(isStore, Size);
1373 Value *AddrCast =
1374 IRB.CreatePointerCast(Addr, PointerType::get(IRB.getInt8Ty(), 0));
1375 if (Getter) {
1376 ShadowOriginPtrs = IRB.CreateCall(Getter, AddrCast);
1377 } else {
1378 Value *SizeVal = ConstantInt::get(MS.IntptrTy, Size);
1379 ShadowOriginPtrs = IRB.CreateCall(isStore ? MS.MsanMetadataPtrForStoreN
1380 : MS.MsanMetadataPtrForLoadN,
1381 {AddrCast, SizeVal});
1382 }
1383 Value *ShadowPtr = IRB.CreateExtractValue(ShadowOriginPtrs, 0);
1384 ShadowPtr = IRB.CreatePointerCast(ShadowPtr, PointerType::get(ShadowTy, 0));
1385 Value *OriginPtr = IRB.CreateExtractValue(ShadowOriginPtrs, 1);
1386
1387 return std::make_pair(ShadowPtr, OriginPtr);
1388 }
1389
1390 std::pair<Value *, Value *> getShadowOriginPtr(Value *Addr, IRBuilder<> &IRB,
1391 Type *ShadowTy,
1392 unsigned Alignment,
1393 bool isStore) {
1394 std::pair<Value *, Value *> ret;
1395 if (MS.CompileKernel)
1396 ret = getShadowOriginPtrKernel(Addr, IRB, ShadowTy, Alignment, isStore);
1397 else
1398 ret = getShadowOriginPtrUserspace(Addr, IRB, ShadowTy, Alignment);
1399 return ret;
1400 }
1401
1402 /// Compute the shadow address for a given function argument.
1403 ///
1404 /// Shadow = ParamTLS+ArgOffset.
1405 Value *getShadowPtrForArgument(Value *A, IRBuilder<> &IRB,
1406 int ArgOffset) {
1407 Value *Base = IRB.CreatePointerCast(MS.ParamTLS, MS.IntptrTy);
1408 if (ArgOffset)
1409 Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
1410 return IRB.CreateIntToPtr(Base, PointerType::get(getShadowTy(A), 0),
1411 "_msarg");
1412 }
1413
1414 /// Compute the origin address for a given function argument.
1415 Value *getOriginPtrForArgument(Value *A, IRBuilder<> &IRB,
1416 int ArgOffset) {
1417 if (!MS.TrackOrigins)
1418 return nullptr;
1419 Value *Base = IRB.CreatePointerCast(MS.ParamOriginTLS, MS.IntptrTy);
1420 if (ArgOffset)
1421 Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
1422 return IRB.CreateIntToPtr(Base, PointerType::get(MS.OriginTy, 0),
1423 "_msarg_o");
1424 }
1425
1426 /// Compute the shadow address for a retval.
1427 Value *getShadowPtrForRetval(Value *A, IRBuilder<> &IRB) {
1428 return IRB.CreatePointerCast(MS.RetvalTLS,
1429 PointerType::get(getShadowTy(A), 0),
1430 "_msret");
1431 }
1432
1433 /// Compute the origin address for a retval.
1434 Value *getOriginPtrForRetval(IRBuilder<> &IRB) {
1435 // We keep a single origin for the entire retval. Might be too optimistic.
1436 return MS.RetvalOriginTLS;
1437 }
1438
1439 /// Set SV to be the shadow value for V.
1440 void setShadow(Value *V, Value *SV) {
1441 assert(!ShadowMap.count(V) && "Values may only have one shadow")((!ShadowMap.count(V) && "Values may only have one shadow"
) ? static_cast<void> (0) : __assert_fail ("!ShadowMap.count(V) && \"Values may only have one shadow\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1441, __PRETTY_FUNCTION__))
;
1442 ShadowMap[V] = PropagateShadow ? SV : getCleanShadow(V);
1443 }
1444
1445 /// Set Origin to be the origin value for V.
1446 void setOrigin(Value *V, Value *Origin) {
1447 if (!MS.TrackOrigins) return;
1448 assert(!OriginMap.count(V) && "Values may only have one origin")((!OriginMap.count(V) && "Values may only have one origin"
) ? static_cast<void> (0) : __assert_fail ("!OriginMap.count(V) && \"Values may only have one origin\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1448, __PRETTY_FUNCTION__))
;
1449 LLVM_DEBUG(dbgs() << "ORIGIN: " << *V << " ==> " << *Origin << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << "ORIGIN: " << *V << " ==> "
<< *Origin << "\n"; } } while (false)
;
1450 OriginMap[V] = Origin;
1451 }
1452
1453 Constant *getCleanShadow(Type *OrigTy) {
1454 Type *ShadowTy = getShadowTy(OrigTy);
1455 if (!ShadowTy)
1456 return nullptr;
1457 return Constant::getNullValue(ShadowTy);
1458 }
1459
1460 /// Create a clean shadow value for a given value.
1461 ///
1462 /// Clean shadow (all zeroes) means all bits of the value are defined
1463 /// (initialized).
1464 Constant *getCleanShadow(Value *V) {
1465 return getCleanShadow(V->getType());
1466 }
1467
1468 /// Create a dirty shadow of a given shadow type.
1469 Constant *getPoisonedShadow(Type *ShadowTy) {
1470 assert(ShadowTy)((ShadowTy) ? static_cast<void> (0) : __assert_fail ("ShadowTy"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1470, __PRETTY_FUNCTION__))
;
1471 if (isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy))
1472 return Constant::getAllOnesValue(ShadowTy);
1473 if (ArrayType *AT = dyn_cast<ArrayType>(ShadowTy)) {
1474 SmallVector<Constant *, 4> Vals(AT->getNumElements(),
1475 getPoisonedShadow(AT->getElementType()));
1476 return ConstantArray::get(AT, Vals);
1477 }
1478 if (StructType *ST = dyn_cast<StructType>(ShadowTy)) {
1479 SmallVector<Constant *, 4> Vals;
1480 for (unsigned i = 0, n = ST->getNumElements(); i < n; i++)
1481 Vals.push_back(getPoisonedShadow(ST->getElementType(i)));
1482 return ConstantStruct::get(ST, Vals);
1483 }
1484 llvm_unreachable("Unexpected shadow type")::llvm::llvm_unreachable_internal("Unexpected shadow type", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1484)
;
1485 }
1486
1487 /// Create a dirty shadow for a given value.
1488 Constant *getPoisonedShadow(Value *V) {
1489 Type *ShadowTy = getShadowTy(V);
1490 if (!ShadowTy)
1491 return nullptr;
1492 return getPoisonedShadow(ShadowTy);
1493 }
1494
1495 /// Create a clean (zero) origin.
1496 Value *getCleanOrigin() {
1497 return Constant::getNullValue(MS.OriginTy);
1498 }
1499
1500 /// Get the shadow value for a given Value.
1501 ///
1502 /// This function either returns the value set earlier with setShadow,
1503 /// or extracts if from ParamTLS (for function arguments).
1504 Value *getShadow(Value *V) {
1505 if (!PropagateShadow) return getCleanShadow(V);
1506 if (Instruction *I = dyn_cast<Instruction>(V)) {
1507 if (I->getMetadata("nosanitize"))
1508 return getCleanShadow(V);
1509 // For instructions the shadow is already stored in the map.
1510 Value *Shadow = ShadowMap[V];
1511 if (!Shadow) {
1512 LLVM_DEBUG(dbgs() << "No shadow: " << *V << "\n" << *(I->getParent()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << "No shadow: " << *V <<
"\n" << *(I->getParent()); } } while (false)
;
1513 (void)I;
1514 assert(Shadow && "No shadow for a value")((Shadow && "No shadow for a value") ? static_cast<
void> (0) : __assert_fail ("Shadow && \"No shadow for a value\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1514, __PRETTY_FUNCTION__))
;
1515 }
1516 return Shadow;
1517 }
1518 if (UndefValue *U = dyn_cast<UndefValue>(V)) {
1519 Value *AllOnes = PoisonUndef ? getPoisonedShadow(V) : getCleanShadow(V);
1520 LLVM_DEBUG(dbgs() << "Undef: " << *U << " ==> " << *AllOnes << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << "Undef: " << *U << " ==> "
<< *AllOnes << "\n"; } } while (false)
;
1521 (void)U;
1522 return AllOnes;
1523 }
1524 if (Argument *A = dyn_cast<Argument>(V)) {
1525 // For arguments we compute the shadow on demand and store it in the map.
1526 Value **ShadowPtr = &ShadowMap[V];
1527 if (*ShadowPtr)
1528 return *ShadowPtr;
1529 Function *F = A->getParent();
1530 IRBuilder<> EntryIRB(ActualFnStart->getFirstNonPHI());
1531 unsigned ArgOffset = 0;
1532 const DataLayout &DL = F->getParent()->getDataLayout();
1533 for (auto &FArg : F->args()) {
1534 if (!FArg.getType()->isSized()) {
1535 LLVM_DEBUG(dbgs() << "Arg is not sized\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << "Arg is not sized\n"; } } while (
false)
;
1536 continue;
1537 }
1538 unsigned Size =
1539 FArg.hasByValAttr()
1540 ? DL.getTypeAllocSize(FArg.getType()->getPointerElementType())
1541 : DL.getTypeAllocSize(FArg.getType());
1542 if (A == &FArg) {
1543 bool Overflow = ArgOffset + Size > kParamTLSSize;
1544 Value *Base = getShadowPtrForArgument(&FArg, EntryIRB, ArgOffset);
1545 if (FArg.hasByValAttr()) {
1546 // ByVal pointer itself has clean shadow. We copy the actual
1547 // argument shadow to the underlying memory.
1548 // Figure out maximal valid memcpy alignment.
1549 unsigned ArgAlign = FArg.getParamAlignment();
1550 if (ArgAlign == 0) {
1551 Type *EltType = A->getType()->getPointerElementType();
1552 ArgAlign = DL.getABITypeAlignment(EltType);
1553 }
1554 Value *CpShadowPtr =
1555 getShadowOriginPtr(V, EntryIRB, EntryIRB.getInt8Ty(), ArgAlign,
1556 /*isStore*/ true)
1557 .first;
1558 // TODO(glider): need to copy origins.
1559 if (Overflow) {
1560 // ParamTLS overflow.
1561 EntryIRB.CreateMemSet(
1562 CpShadowPtr, Constant::getNullValue(EntryIRB.getInt8Ty()),
1563 Size, ArgAlign);
1564 } else {
1565 unsigned CopyAlign = std::min(ArgAlign, kShadowTLSAlignment);
1566 Value *Cpy = EntryIRB.CreateMemCpy(CpShadowPtr, CopyAlign, Base,
1567 CopyAlign, Size);
1568 LLVM_DEBUG(dbgs() << " ByValCpy: " << *Cpy << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " ByValCpy: " << *Cpy <<
"\n"; } } while (false)
;
1569 (void)Cpy;
1570 }
1571 *ShadowPtr = getCleanShadow(V);
1572 } else {
1573 if (Overflow) {
1574 // ParamTLS overflow.
1575 *ShadowPtr = getCleanShadow(V);
1576 } else {
1577 *ShadowPtr =
1578 EntryIRB.CreateAlignedLoad(Base, kShadowTLSAlignment);
1579 }
1580 }
1581 LLVM_DEBUG(dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " ARG: " << FArg <<
" ==> " << **ShadowPtr << "\n"; } } while (false
)
1582 << " ARG: " << FArg << " ==> " << **ShadowPtr << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " ARG: " << FArg <<
" ==> " << **ShadowPtr << "\n"; } } while (false
)
;
1583 if (MS.TrackOrigins && !Overflow) {
1584 Value *OriginPtr =
1585 getOriginPtrForArgument(&FArg, EntryIRB, ArgOffset);
1586 setOrigin(A, EntryIRB.CreateLoad(OriginPtr));
1587 } else {
1588 setOrigin(A, getCleanOrigin());
1589 }
1590 }
1591 ArgOffset += alignTo(Size, kShadowTLSAlignment);
1592 }
1593 assert(*ShadowPtr && "Could not find shadow for an argument")((*ShadowPtr && "Could not find shadow for an argument"
) ? static_cast<void> (0) : __assert_fail ("*ShadowPtr && \"Could not find shadow for an argument\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1593, __PRETTY_FUNCTION__))
;
1594 return *ShadowPtr;
1595 }
1596 // For everything else the shadow is zero.
1597 return getCleanShadow(V);
1598 }
1599
1600 /// Get the shadow for i-th argument of the instruction I.
1601 Value *getShadow(Instruction *I, int i) {
1602 return getShadow(I->getOperand(i));
1603 }
1604
1605 /// Get the origin for a value.
1606 Value *getOrigin(Value *V) {
1607 if (!MS.TrackOrigins) return nullptr;
1608 if (!PropagateShadow) return getCleanOrigin();
1609 if (isa<Constant>(V)) return getCleanOrigin();
1610 assert((isa<Instruction>(V) || isa<Argument>(V)) &&(((isa<Instruction>(V) || isa<Argument>(V)) &&
"Unexpected value type in getOrigin()") ? static_cast<void
> (0) : __assert_fail ("(isa<Instruction>(V) || isa<Argument>(V)) && \"Unexpected value type in getOrigin()\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1611, __PRETTY_FUNCTION__))
1611 "Unexpected value type in getOrigin()")(((isa<Instruction>(V) || isa<Argument>(V)) &&
"Unexpected value type in getOrigin()") ? static_cast<void
> (0) : __assert_fail ("(isa<Instruction>(V) || isa<Argument>(V)) && \"Unexpected value type in getOrigin()\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1611, __PRETTY_FUNCTION__))
;
1612 if (Instruction *I = dyn_cast<Instruction>(V)) {
1613 if (I->getMetadata("nosanitize"))
1614 return getCleanOrigin();
1615 }
1616 Value *Origin = OriginMap[V];
1617 assert(Origin && "Missing origin")((Origin && "Missing origin") ? static_cast<void>
(0) : __assert_fail ("Origin && \"Missing origin\"",
"/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1617, __PRETTY_FUNCTION__))
;
1618 return Origin;
1619 }
1620
1621 /// Get the origin for i-th argument of the instruction I.
1622 Value *getOrigin(Instruction *I, int i) {
1623 return getOrigin(I->getOperand(i));
1624 }
1625
1626 /// Remember the place where a shadow check should be inserted.
1627 ///
1628 /// This location will be later instrumented with a check that will print a
1629 /// UMR warning in runtime if the shadow value is not 0.
1630 void insertShadowCheck(Value *Shadow, Value *Origin, Instruction *OrigIns) {
1631 assert(Shadow)((Shadow) ? static_cast<void> (0) : __assert_fail ("Shadow"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1631, __PRETTY_FUNCTION__))
;
1632 if (!InsertChecks) return;
1633#ifndef NDEBUG
1634 Type *ShadowTy = Shadow->getType();
1635 assert((isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy)) &&(((isa<IntegerType>(ShadowTy) || isa<VectorType>(
ShadowTy)) && "Can only insert checks for integer and vector shadow types"
) ? static_cast<void> (0) : __assert_fail ("(isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy)) && \"Can only insert checks for integer and vector shadow types\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1636, __PRETTY_FUNCTION__))
1636 "Can only insert checks for integer and vector shadow types")(((isa<IntegerType>(ShadowTy) || isa<VectorType>(
ShadowTy)) && "Can only insert checks for integer and vector shadow types"
) ? static_cast<void> (0) : __assert_fail ("(isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy)) && \"Can only insert checks for integer and vector shadow types\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1636, __PRETTY_FUNCTION__))
;
1637#endif
1638 InstrumentationList.push_back(
1639 ShadowOriginAndInsertPoint(Shadow, Origin, OrigIns));
1640 }
1641
1642 /// Remember the place where a shadow check should be inserted.
1643 ///
1644 /// This location will be later instrumented with a check that will print a
1645 /// UMR warning in runtime if the value is not fully defined.
1646 void insertShadowCheck(Value *Val, Instruction *OrigIns) {
1647 assert(Val)((Val) ? static_cast<void> (0) : __assert_fail ("Val", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1647, __PRETTY_FUNCTION__))
;
1648 Value *Shadow, *Origin;
1649 if (ClCheckConstantShadow) {
1650 Shadow = getShadow(Val);
1651 if (!Shadow) return;
1652 Origin = getOrigin(Val);
1653 } else {
1654 Shadow = dyn_cast_or_null<Instruction>(getShadow(Val));
1655 if (!Shadow) return;
1656 Origin = dyn_cast_or_null<Instruction>(getOrigin(Val));
1657 }
1658 insertShadowCheck(Shadow, Origin, OrigIns);
1659 }
1660
1661 AtomicOrdering addReleaseOrdering(AtomicOrdering a) {
1662 switch (a) {
1663 case AtomicOrdering::NotAtomic:
1664 return AtomicOrdering::NotAtomic;
1665 case AtomicOrdering::Unordered:
1666 case AtomicOrdering::Monotonic:
1667 case AtomicOrdering::Release:
1668 return AtomicOrdering::Release;
1669 case AtomicOrdering::Acquire:
1670 case AtomicOrdering::AcquireRelease:
1671 return AtomicOrdering::AcquireRelease;
1672 case AtomicOrdering::SequentiallyConsistent:
1673 return AtomicOrdering::SequentiallyConsistent;
1674 }
1675 llvm_unreachable("Unknown ordering")::llvm::llvm_unreachable_internal("Unknown ordering", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1675)
;
1676 }
1677
1678 AtomicOrdering addAcquireOrdering(AtomicOrdering a) {
1679 switch (a) {
1680 case AtomicOrdering::NotAtomic:
1681 return AtomicOrdering::NotAtomic;
1682 case AtomicOrdering::Unordered:
1683 case AtomicOrdering::Monotonic:
1684 case AtomicOrdering::Acquire:
1685 return AtomicOrdering::Acquire;
1686 case AtomicOrdering::Release:
1687 case AtomicOrdering::AcquireRelease:
1688 return AtomicOrdering::AcquireRelease;
1689 case AtomicOrdering::SequentiallyConsistent:
1690 return AtomicOrdering::SequentiallyConsistent;
1691 }
1692 llvm_unreachable("Unknown ordering")::llvm::llvm_unreachable_internal("Unknown ordering", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1692)
;
1693 }
1694
1695 // ------------------- Visitors.
1696 using InstVisitor<MemorySanitizerVisitor>::visit;
1697 void visit(Instruction &I) {
1698 if (!I.getMetadata("nosanitize"))
1699 InstVisitor<MemorySanitizerVisitor>::visit(I);
1700 }
1701
1702 /// Instrument LoadInst
1703 ///
1704 /// Loads the corresponding shadow and (optionally) origin.
1705 /// Optionally, checks that the load address is fully defined.
1706 void visitLoadInst(LoadInst &I) {
1707 assert(I.getType()->isSized() && "Load type must have size")((I.getType()->isSized() && "Load type must have size"
) ? static_cast<void> (0) : __assert_fail ("I.getType()->isSized() && \"Load type must have size\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1707, __PRETTY_FUNCTION__))
;
1708 assert(!I.getMetadata("nosanitize"))((!I.getMetadata("nosanitize")) ? static_cast<void> (0)
: __assert_fail ("!I.getMetadata(\"nosanitize\")", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1708, __PRETTY_FUNCTION__))
;
1709 IRBuilder<> IRB(I.getNextNode());
1710 Type *ShadowTy = getShadowTy(&I);
1711 Value *Addr = I.getPointerOperand();
1712 Value *ShadowPtr, *OriginPtr;
1713 unsigned Alignment = I.getAlignment();
1714 if (PropagateShadow) {
1715 std::tie(ShadowPtr, OriginPtr) =
1716 getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ false);
1717 setShadow(&I, IRB.CreateAlignedLoad(ShadowPtr, Alignment, "_msld"));
1718 } else {
1719 setShadow(&I, getCleanShadow(&I));
1720 }
1721
1722 if (ClCheckAccessAddress)
1723 insertShadowCheck(I.getPointerOperand(), &I);
1724
1725 if (I.isAtomic())
1726 I.setOrdering(addAcquireOrdering(I.getOrdering()));
1727
1728 if (MS.TrackOrigins) {
1729 if (PropagateShadow) {
1730 unsigned OriginAlignment = std::max(kMinOriginAlignment, Alignment);
1731 setOrigin(&I, IRB.CreateAlignedLoad(OriginPtr, OriginAlignment));
1732 } else {
1733 setOrigin(&I, getCleanOrigin());
1734 }
1735 }
1736 }
1737
1738 /// Instrument StoreInst
1739 ///
1740 /// Stores the corresponding shadow and (optionally) origin.
1741 /// Optionally, checks that the store address is fully defined.
1742 void visitStoreInst(StoreInst &I) {
1743 StoreList.push_back(&I);
1744 if (ClCheckAccessAddress)
1745 insertShadowCheck(I.getPointerOperand(), &I);
1746 }
1747
1748 void handleCASOrRMW(Instruction &I) {
1749 assert(isa<AtomicRMWInst>(I) || isa<AtomicCmpXchgInst>(I))((isa<AtomicRMWInst>(I) || isa<AtomicCmpXchgInst>
(I)) ? static_cast<void> (0) : __assert_fail ("isa<AtomicRMWInst>(I) || isa<AtomicCmpXchgInst>(I)"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1749, __PRETTY_FUNCTION__))
;
1750
1751 IRBuilder<> IRB(&I);
1752 Value *Addr = I.getOperand(0);
1753 Value *ShadowPtr = getShadowOriginPtr(Addr, IRB, I.getType(),
1754 /*Alignment*/ 1, /*isStore*/ true)
1755 .first;
1756
1757 if (ClCheckAccessAddress)
1758 insertShadowCheck(Addr, &I);
1759
1760 // Only test the conditional argument of cmpxchg instruction.
1761 // The other argument can potentially be uninitialized, but we can not
1762 // detect this situation reliably without possible false positives.
1763 if (isa<AtomicCmpXchgInst>(I))
1764 insertShadowCheck(I.getOperand(1), &I);
1765
1766 IRB.CreateStore(getCleanShadow(&I), ShadowPtr);
1767
1768 setShadow(&I, getCleanShadow(&I));
1769 setOrigin(&I, getCleanOrigin());
1770 }
1771
1772 void visitAtomicRMWInst(AtomicRMWInst &I) {
1773 handleCASOrRMW(I);
1774 I.setOrdering(addReleaseOrdering(I.getOrdering()));
1775 }
1776
1777 void visitAtomicCmpXchgInst(AtomicCmpXchgInst &I) {
1778 handleCASOrRMW(I);
1779 I.setSuccessOrdering(addReleaseOrdering(I.getSuccessOrdering()));
1780 }
1781
1782 // Vector manipulation.
1783 void visitExtractElementInst(ExtractElementInst &I) {
1784 insertShadowCheck(I.getOperand(1), &I);
1785 IRBuilder<> IRB(&I);
1786 setShadow(&I, IRB.CreateExtractElement(getShadow(&I, 0), I.getOperand(1),
1787 "_msprop"));
1788 setOrigin(&I, getOrigin(&I, 0));
1789 }
1790
1791 void visitInsertElementInst(InsertElementInst &I) {
1792 insertShadowCheck(I.getOperand(2), &I);
1793 IRBuilder<> IRB(&I);
1794 setShadow(&I, IRB.CreateInsertElement(getShadow(&I, 0), getShadow(&I, 1),
1795 I.getOperand(2), "_msprop"));
1796 setOriginForNaryOp(I);
1797 }
1798
1799 void visitShuffleVectorInst(ShuffleVectorInst &I) {
1800 insertShadowCheck(I.getOperand(2), &I);
1801 IRBuilder<> IRB(&I);
1802 setShadow(&I, IRB.CreateShuffleVector(getShadow(&I, 0), getShadow(&I, 1),
1803 I.getOperand(2), "_msprop"));
1804 setOriginForNaryOp(I);
1805 }
1806
1807 // Casts.
1808 void visitSExtInst(SExtInst &I) {
1809 IRBuilder<> IRB(&I);
1810 setShadow(&I, IRB.CreateSExt(getShadow(&I, 0), I.getType(), "_msprop"));
1811 setOrigin(&I, getOrigin(&I, 0));
1812 }
1813
1814 void visitZExtInst(ZExtInst &I) {
1815 IRBuilder<> IRB(&I);
1816 setShadow(&I, IRB.CreateZExt(getShadow(&I, 0), I.getType(), "_msprop"));
1817 setOrigin(&I, getOrigin(&I, 0));
1818 }
1819
1820 void visitTruncInst(TruncInst &I) {
1821 IRBuilder<> IRB(&I);
1822 setShadow(&I, IRB.CreateTrunc(getShadow(&I, 0), I.getType(), "_msprop"));
1823 setOrigin(&I, getOrigin(&I, 0));
1824 }
1825
1826 void visitBitCastInst(BitCastInst &I) {
1827 // Special case: if this is the bitcast (there is exactly 1 allowed) between
1828 // a musttail call and a ret, don't instrument. New instructions are not
1829 // allowed after a musttail call.
1830 if (auto *CI = dyn_cast<CallInst>(I.getOperand(0)))
1831 if (CI->isMustTailCall())
1832 return;
1833 IRBuilder<> IRB(&I);
1834 setShadow(&I, IRB.CreateBitCast(getShadow(&I, 0), getShadowTy(&I)));
1835 setOrigin(&I, getOrigin(&I, 0));
1836 }
1837
1838 void visitPtrToIntInst(PtrToIntInst &I) {
1839 IRBuilder<> IRB(&I);
1840 setShadow(&I, IRB.CreateIntCast(getShadow(&I, 0), getShadowTy(&I), false,
1841 "_msprop_ptrtoint"));
1842 setOrigin(&I, getOrigin(&I, 0));
1843 }
1844
1845 void visitIntToPtrInst(IntToPtrInst &I) {
1846 IRBuilder<> IRB(&I);
1847 setShadow(&I, IRB.CreateIntCast(getShadow(&I, 0), getShadowTy(&I), false,
1848 "_msprop_inttoptr"));
1849 setOrigin(&I, getOrigin(&I, 0));
1850 }
1851
1852 void visitFPToSIInst(CastInst& I) { handleShadowOr(I); }
1853 void visitFPToUIInst(CastInst& I) { handleShadowOr(I); }
1854 void visitSIToFPInst(CastInst& I) { handleShadowOr(I); }
1855 void visitUIToFPInst(CastInst& I) { handleShadowOr(I); }
1856 void visitFPExtInst(CastInst& I) { handleShadowOr(I); }
1857 void visitFPTruncInst(CastInst& I) { handleShadowOr(I); }
1858
1859 /// Propagate shadow for bitwise AND.
1860 ///
1861 /// This code is exact, i.e. if, for example, a bit in the left argument
1862 /// is defined and 0, then neither the value not definedness of the
1863 /// corresponding bit in B don't affect the resulting shadow.
1864 void visitAnd(BinaryOperator &I) {
1865 IRBuilder<> IRB(&I);
1866 // "And" of 0 and a poisoned value results in unpoisoned value.
1867 // 1&1 => 1; 0&1 => 0; p&1 => p;
1868 // 1&0 => 0; 0&0 => 0; p&0 => 0;
1869 // 1&p => p; 0&p => 0; p&p => p;
1870 // S = (S1 & S2) | (V1 & S2) | (S1 & V2)
1871 Value *S1 = getShadow(&I, 0);
1872 Value *S2 = getShadow(&I, 1);
1873 Value *V1 = I.getOperand(0);
1874 Value *V2 = I.getOperand(1);
1875 if (V1->getType() != S1->getType()) {
1876 V1 = IRB.CreateIntCast(V1, S1->getType(), false);
1877 V2 = IRB.CreateIntCast(V2, S2->getType(), false);
1878 }
1879 Value *S1S2 = IRB.CreateAnd(S1, S2);
1880 Value *V1S2 = IRB.CreateAnd(V1, S2);
1881 Value *S1V2 = IRB.CreateAnd(S1, V2);
1882 setShadow(&I, IRB.CreateOr(S1S2, IRB.CreateOr(V1S2, S1V2)));
1883 setOriginForNaryOp(I);
1884 }
1885
1886 void visitOr(BinaryOperator &I) {
1887 IRBuilder<> IRB(&I);
1888 // "Or" of 1 and a poisoned value results in unpoisoned value.
1889 // 1|1 => 1; 0|1 => 1; p|1 => 1;
1890 // 1|0 => 1; 0|0 => 0; p|0 => p;
1891 // 1|p => 1; 0|p => p; p|p => p;
1892 // S = (S1 & S2) | (~V1 & S2) | (S1 & ~V2)
1893 Value *S1 = getShadow(&I, 0);
1894 Value *S2 = getShadow(&I, 1);
1895 Value *V1 = IRB.CreateNot(I.getOperand(0));
1896 Value *V2 = IRB.CreateNot(I.getOperand(1));
1897 if (V1->getType() != S1->getType()) {
1898 V1 = IRB.CreateIntCast(V1, S1->getType(), false);
1899 V2 = IRB.CreateIntCast(V2, S2->getType(), false);
1900 }
1901 Value *S1S2 = IRB.CreateAnd(S1, S2);
1902 Value *V1S2 = IRB.CreateAnd(V1, S2);
1903 Value *S1V2 = IRB.CreateAnd(S1, V2);
1904 setShadow(&I, IRB.CreateOr(S1S2, IRB.CreateOr(V1S2, S1V2)));
1905 setOriginForNaryOp(I);
1906 }
1907
1908 /// Default propagation of shadow and/or origin.
1909 ///
1910 /// This class implements the general case of shadow propagation, used in all
1911 /// cases where we don't know and/or don't care about what the operation
1912 /// actually does. It converts all input shadow values to a common type
1913 /// (extending or truncating as necessary), and bitwise OR's them.
1914 ///
1915 /// This is much cheaper than inserting checks (i.e. requiring inputs to be
1916 /// fully initialized), and less prone to false positives.
1917 ///
1918 /// This class also implements the general case of origin propagation. For a
1919 /// Nary operation, result origin is set to the origin of an argument that is
1920 /// not entirely initialized. If there is more than one such arguments, the
1921 /// rightmost of them is picked. It does not matter which one is picked if all
1922 /// arguments are initialized.
1923 template <bool CombineShadow>
1924 class Combiner {
1925 Value *Shadow = nullptr;
1926 Value *Origin = nullptr;
1927 IRBuilder<> &IRB;
1928 MemorySanitizerVisitor *MSV;
1929
1930 public:
1931 Combiner(MemorySanitizerVisitor *MSV, IRBuilder<> &IRB)
1932 : IRB(IRB), MSV(MSV) {}
1933
1934 /// Add a pair of shadow and origin values to the mix.
1935 Combiner &Add(Value *OpShadow, Value *OpOrigin) {
1936 if (CombineShadow) {
1937 assert(OpShadow)((OpShadow) ? static_cast<void> (0) : __assert_fail ("OpShadow"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1937, __PRETTY_FUNCTION__))
;
1938 if (!Shadow)
1939 Shadow = OpShadow;
1940 else {
1941 OpShadow = MSV->CreateShadowCast(IRB, OpShadow, Shadow->getType());
1942 Shadow = IRB.CreateOr(Shadow, OpShadow, "_msprop");
1943 }
1944 }
1945
1946 if (MSV->MS.TrackOrigins) {
1947 assert(OpOrigin)((OpOrigin) ? static_cast<void> (0) : __assert_fail ("OpOrigin"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1947, __PRETTY_FUNCTION__))
;
1948 if (!Origin) {
1949 Origin = OpOrigin;
1950 } else {
1951 Constant *ConstOrigin = dyn_cast<Constant>(OpOrigin);
1952 // No point in adding something that might result in 0 origin value.
1953 if (!ConstOrigin || !ConstOrigin->isNullValue()) {
1954 Value *FlatShadow = MSV->convertToShadowTyNoVec(OpShadow, IRB);
1955 Value *Cond =
1956 IRB.CreateICmpNE(FlatShadow, MSV->getCleanShadow(FlatShadow));
1957 Origin = IRB.CreateSelect(Cond, OpOrigin, Origin);
1958 }
1959 }
1960 }
1961 return *this;
1962 }
1963
1964 /// Add an application value to the mix.
1965 Combiner &Add(Value *V) {
1966 Value *OpShadow = MSV->getShadow(V);
1967 Value *OpOrigin = MSV->MS.TrackOrigins ? MSV->getOrigin(V) : nullptr;
1968 return Add(OpShadow, OpOrigin);
1969 }
1970
1971 /// Set the current combined values as the given instruction's shadow
1972 /// and origin.
1973 void Done(Instruction *I) {
1974 if (CombineShadow) {
1975 assert(Shadow)((Shadow) ? static_cast<void> (0) : __assert_fail ("Shadow"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1975, __PRETTY_FUNCTION__))
;
1976 Shadow = MSV->CreateShadowCast(IRB, Shadow, MSV->getShadowTy(I));
1977 MSV->setShadow(I, Shadow);
1978 }
1979 if (MSV->MS.TrackOrigins) {
1980 assert(Origin)((Origin) ? static_cast<void> (0) : __assert_fail ("Origin"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 1980, __PRETTY_FUNCTION__))
;
1981 MSV->setOrigin(I, Origin);
1982 }
1983 }
1984 };
1985
1986 using ShadowAndOriginCombiner = Combiner<true>;
1987 using OriginCombiner = Combiner<false>;
1988
1989 /// Propagate origin for arbitrary operation.
1990 void setOriginForNaryOp(Instruction &I) {
1991 if (!MS.TrackOrigins) return;
1992 IRBuilder<> IRB(&I);
1993 OriginCombiner OC(this, IRB);
1994 for (Instruction::op_iterator OI = I.op_begin(); OI != I.op_end(); ++OI)
1995 OC.Add(OI->get());
1996 OC.Done(&I);
1997 }
1998
1999 size_t VectorOrPrimitiveTypeSizeInBits(Type *Ty) {
2000 assert(!(Ty->isVectorTy() && Ty->getScalarType()->isPointerTy()) &&((!(Ty->isVectorTy() && Ty->getScalarType()->
isPointerTy()) && "Vector of pointers is not a valid shadow type"
) ? static_cast<void> (0) : __assert_fail ("!(Ty->isVectorTy() && Ty->getScalarType()->isPointerTy()) && \"Vector of pointers is not a valid shadow type\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2001, __PRETTY_FUNCTION__))
2001 "Vector of pointers is not a valid shadow type")((!(Ty->isVectorTy() && Ty->getScalarType()->
isPointerTy()) && "Vector of pointers is not a valid shadow type"
) ? static_cast<void> (0) : __assert_fail ("!(Ty->isVectorTy() && Ty->getScalarType()->isPointerTy()) && \"Vector of pointers is not a valid shadow type\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2001, __PRETTY_FUNCTION__))
;
2002 return Ty->isVectorTy() ?
2003 Ty->getVectorNumElements() * Ty->getScalarSizeInBits() :
2004 Ty->getPrimitiveSizeInBits();
2005 }
2006
2007 /// Cast between two shadow types, extending or truncating as
2008 /// necessary.
2009 Value *CreateShadowCast(IRBuilder<> &IRB, Value *V, Type *dstTy,
2010 bool Signed = false) {
2011 Type *srcTy = V->getType();
2012 size_t srcSizeInBits = VectorOrPrimitiveTypeSizeInBits(srcTy);
2013 size_t dstSizeInBits = VectorOrPrimitiveTypeSizeInBits(dstTy);
2014 if (srcSizeInBits > 1 && dstSizeInBits == 1)
2015 return IRB.CreateICmpNE(V, getCleanShadow(V));
2016
2017 if (dstTy->isIntegerTy() && srcTy->isIntegerTy())
2018 return IRB.CreateIntCast(V, dstTy, Signed);
2019 if (dstTy->isVectorTy() && srcTy->isVectorTy() &&
2020 dstTy->getVectorNumElements() == srcTy->getVectorNumElements())
2021 return IRB.CreateIntCast(V, dstTy, Signed);
2022 Value *V1 = IRB.CreateBitCast(V, Type::getIntNTy(*MS.C, srcSizeInBits));
2023 Value *V2 =
2024 IRB.CreateIntCast(V1, Type::getIntNTy(*MS.C, dstSizeInBits), Signed);
2025 return IRB.CreateBitCast(V2, dstTy);
2026 // TODO: handle struct types.
2027 }
2028
2029 /// Cast an application value to the type of its own shadow.
2030 Value *CreateAppToShadowCast(IRBuilder<> &IRB, Value *V) {
2031 Type *ShadowTy = getShadowTy(V);
2032 if (V->getType() == ShadowTy)
2033 return V;
2034 if (V->getType()->isPtrOrPtrVectorTy())
2035 return IRB.CreatePtrToInt(V, ShadowTy);
2036 else
2037 return IRB.CreateBitCast(V, ShadowTy);
2038 }
2039
2040 /// Propagate shadow for arbitrary operation.
2041 void handleShadowOr(Instruction &I) {
2042 IRBuilder<> IRB(&I);
2043 ShadowAndOriginCombiner SC(this, IRB);
2044 for (Instruction::op_iterator OI = I.op_begin(); OI != I.op_end(); ++OI)
2045 SC.Add(OI->get());
2046 SC.Done(&I);
2047 }
2048
2049 // Handle multiplication by constant.
2050 //
2051 // Handle a special case of multiplication by constant that may have one or
2052 // more zeros in the lower bits. This makes corresponding number of lower bits
2053 // of the result zero as well. We model it by shifting the other operand
2054 // shadow left by the required number of bits. Effectively, we transform
2055 // (X * (A * 2**B)) to ((X << B) * A) and instrument (X << B) as (Sx << B).
2056 // We use multiplication by 2**N instead of shift to cover the case of
2057 // multiplication by 0, which may occur in some elements of a vector operand.
2058 void handleMulByConstant(BinaryOperator &I, Constant *ConstArg,
2059 Value *OtherArg) {
2060 Constant *ShadowMul;
2061 Type *Ty = ConstArg->getType();
2062 if (Ty->isVectorTy()) {
2063 unsigned NumElements = Ty->getVectorNumElements();
2064 Type *EltTy = Ty->getSequentialElementType();
2065 SmallVector<Constant *, 16> Elements;
2066 for (unsigned Idx = 0; Idx < NumElements; ++Idx) {
2067 if (ConstantInt *Elt =
2068 dyn_cast<ConstantInt>(ConstArg->getAggregateElement(Idx))) {
2069 const APInt &V = Elt->getValue();
2070 APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros();
2071 Elements.push_back(ConstantInt::get(EltTy, V2));
2072 } else {
2073 Elements.push_back(ConstantInt::get(EltTy, 1));
2074 }
2075 }
2076 ShadowMul = ConstantVector::get(Elements);
2077 } else {
2078 if (ConstantInt *Elt = dyn_cast<ConstantInt>(ConstArg)) {
2079 const APInt &V = Elt->getValue();
2080 APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros();
2081 ShadowMul = ConstantInt::get(Ty, V2);
2082 } else {
2083 ShadowMul = ConstantInt::get(Ty, 1);
2084 }
2085 }
2086
2087 IRBuilder<> IRB(&I);
2088 setShadow(&I,
2089 IRB.CreateMul(getShadow(OtherArg), ShadowMul, "msprop_mul_cst"));
2090 setOrigin(&I, getOrigin(OtherArg));
2091 }
2092
2093 void visitMul(BinaryOperator &I) {
2094 Constant *constOp0 = dyn_cast<Constant>(I.getOperand(0));
2095 Constant *constOp1 = dyn_cast<Constant>(I.getOperand(1));
2096 if (constOp0 && !constOp1)
2097 handleMulByConstant(I, constOp0, I.getOperand(1));
2098 else if (constOp1 && !constOp0)
2099 handleMulByConstant(I, constOp1, I.getOperand(0));
2100 else
2101 handleShadowOr(I);
2102 }
2103
2104 void visitFAdd(BinaryOperator &I) { handleShadowOr(I); }
2105 void visitFSub(BinaryOperator &I) { handleShadowOr(I); }
2106 void visitFMul(BinaryOperator &I) { handleShadowOr(I); }
2107 void visitAdd(BinaryOperator &I) { handleShadowOr(I); }
2108 void visitSub(BinaryOperator &I) { handleShadowOr(I); }
2109 void visitXor(BinaryOperator &I) { handleShadowOr(I); }
2110
2111 void handleIntegerDiv(Instruction &I) {
2112 IRBuilder<> IRB(&I);
2113 // Strict on the second argument.
2114 insertShadowCheck(I.getOperand(1), &I);
2115 setShadow(&I, getShadow(&I, 0));
2116 setOrigin(&I, getOrigin(&I, 0));
2117 }
2118
2119 void visitUDiv(BinaryOperator &I) { handleIntegerDiv(I); }
2120 void visitSDiv(BinaryOperator &I) { handleIntegerDiv(I); }
2121 void visitURem(BinaryOperator &I) { handleIntegerDiv(I); }
2122 void visitSRem(BinaryOperator &I) { handleIntegerDiv(I); }
2123
2124 // Floating point division is side-effect free. We can not require that the
2125 // divisor is fully initialized and must propagate shadow. See PR37523.
2126 void visitFDiv(BinaryOperator &I) { handleShadowOr(I); }
2127 void visitFRem(BinaryOperator &I) { handleShadowOr(I); }
2128
2129 /// Instrument == and != comparisons.
2130 ///
2131 /// Sometimes the comparison result is known even if some of the bits of the
2132 /// arguments are not.
2133 void handleEqualityComparison(ICmpInst &I) {
2134 IRBuilder<> IRB(&I);
2135 Value *A = I.getOperand(0);
2136 Value *B = I.getOperand(1);
2137 Value *Sa = getShadow(A);
2138 Value *Sb = getShadow(B);
2139
2140 // Get rid of pointers and vectors of pointers.
2141 // For ints (and vectors of ints), types of A and Sa match,
2142 // and this is a no-op.
2143 A = IRB.CreatePointerCast(A, Sa->getType());
2144 B = IRB.CreatePointerCast(B, Sb->getType());
2145
2146 // A == B <==> (C = A^B) == 0
2147 // A != B <==> (C = A^B) != 0
2148 // Sc = Sa | Sb
2149 Value *C = IRB.CreateXor(A, B);
2150 Value *Sc = IRB.CreateOr(Sa, Sb);
2151 // Now dealing with i = (C == 0) comparison (or C != 0, does not matter now)
2152 // Result is defined if one of the following is true
2153 // * there is a defined 1 bit in C
2154 // * C is fully defined
2155 // Si = !(C & ~Sc) && Sc
2156 Value *Zero = Constant::getNullValue(Sc->getType());
2157 Value *MinusOne = Constant::getAllOnesValue(Sc->getType());
2158 Value *Si =
2159 IRB.CreateAnd(IRB.CreateICmpNE(Sc, Zero),
2160 IRB.CreateICmpEQ(
2161 IRB.CreateAnd(IRB.CreateXor(Sc, MinusOne), C), Zero));
2162 Si->setName("_msprop_icmp");
2163 setShadow(&I, Si);
2164 setOriginForNaryOp(I);
2165 }
2166
2167 /// Build the lowest possible value of V, taking into account V's
2168 /// uninitialized bits.
2169 Value *getLowestPossibleValue(IRBuilder<> &IRB, Value *A, Value *Sa,
2170 bool isSigned) {
2171 if (isSigned) {
2172 // Split shadow into sign bit and other bits.
2173 Value *SaOtherBits = IRB.CreateLShr(IRB.CreateShl(Sa, 1), 1);
2174 Value *SaSignBit = IRB.CreateXor(Sa, SaOtherBits);
2175 // Maximise the undefined shadow bit, minimize other undefined bits.
2176 return
2177 IRB.CreateOr(IRB.CreateAnd(A, IRB.CreateNot(SaOtherBits)), SaSignBit);
2178 } else {
2179 // Minimize undefined bits.
2180 return IRB.CreateAnd(A, IRB.CreateNot(Sa));
2181 }
2182 }
2183
2184 /// Build the highest possible value of V, taking into account V's
2185 /// uninitialized bits.
2186 Value *getHighestPossibleValue(IRBuilder<> &IRB, Value *A, Value *Sa,
2187 bool isSigned) {
2188 if (isSigned) {
2189 // Split shadow into sign bit and other bits.
2190 Value *SaOtherBits = IRB.CreateLShr(IRB.CreateShl(Sa, 1), 1);
2191 Value *SaSignBit = IRB.CreateXor(Sa, SaOtherBits);
2192 // Minimise the undefined shadow bit, maximise other undefined bits.
2193 return
2194 IRB.CreateOr(IRB.CreateAnd(A, IRB.CreateNot(SaSignBit)), SaOtherBits);
2195 } else {
2196 // Maximize undefined bits.
2197 return IRB.CreateOr(A, Sa);
2198 }
2199 }
2200
2201 /// Instrument relational comparisons.
2202 ///
2203 /// This function does exact shadow propagation for all relational
2204 /// comparisons of integers, pointers and vectors of those.
2205 /// FIXME: output seems suboptimal when one of the operands is a constant
2206 void handleRelationalComparisonExact(ICmpInst &I) {
2207 IRBuilder<> IRB(&I);
2208 Value *A = I.getOperand(0);
2209 Value *B = I.getOperand(1);
2210 Value *Sa = getShadow(A);
2211 Value *Sb = getShadow(B);
2212
2213 // Get rid of pointers and vectors of pointers.
2214 // For ints (and vectors of ints), types of A and Sa match,
2215 // and this is a no-op.
2216 A = IRB.CreatePointerCast(A, Sa->getType());
2217 B = IRB.CreatePointerCast(B, Sb->getType());
2218
2219 // Let [a0, a1] be the interval of possible values of A, taking into account
2220 // its undefined bits. Let [b0, b1] be the interval of possible values of B.
2221 // Then (A cmp B) is defined iff (a0 cmp b1) == (a1 cmp b0).
2222 bool IsSigned = I.isSigned();
2223 Value *S1 = IRB.CreateICmp(I.getPredicate(),
2224 getLowestPossibleValue(IRB, A, Sa, IsSigned),
2225 getHighestPossibleValue(IRB, B, Sb, IsSigned));
2226 Value *S2 = IRB.CreateICmp(I.getPredicate(),
2227 getHighestPossibleValue(IRB, A, Sa, IsSigned),
2228 getLowestPossibleValue(IRB, B, Sb, IsSigned));
2229 Value *Si = IRB.CreateXor(S1, S2);
2230 setShadow(&I, Si);
2231 setOriginForNaryOp(I);
2232 }
2233
2234 /// Instrument signed relational comparisons.
2235 ///
2236 /// Handle sign bit tests: x<0, x>=0, x<=-1, x>-1 by propagating the highest
2237 /// bit of the shadow. Everything else is delegated to handleShadowOr().
2238 void handleSignedRelationalComparison(ICmpInst &I) {
2239 Constant *constOp;
2240 Value *op = nullptr;
2241 CmpInst::Predicate pre;
2242 if ((constOp = dyn_cast<Constant>(I.getOperand(1)))) {
2243 op = I.getOperand(0);
2244 pre = I.getPredicate();
2245 } else if ((constOp = dyn_cast<Constant>(I.getOperand(0)))) {
2246 op = I.getOperand(1);
2247 pre = I.getSwappedPredicate();
2248 } else {
2249 handleShadowOr(I);
2250 return;
2251 }
2252
2253 if ((constOp->isNullValue() &&
2254 (pre == CmpInst::ICMP_SLT || pre == CmpInst::ICMP_SGE)) ||
2255 (constOp->isAllOnesValue() &&
2256 (pre == CmpInst::ICMP_SGT || pre == CmpInst::ICMP_SLE))) {
2257 IRBuilder<> IRB(&I);
2258 Value *Shadow = IRB.CreateICmpSLT(getShadow(op), getCleanShadow(op),
2259 "_msprop_icmp_s");
2260 setShadow(&I, Shadow);
2261 setOrigin(&I, getOrigin(op));
2262 } else {
2263 handleShadowOr(I);
2264 }
2265 }
2266
2267 void visitICmpInst(ICmpInst &I) {
2268 if (!ClHandleICmp) {
2269 handleShadowOr(I);
2270 return;
2271 }
2272 if (I.isEquality()) {
2273 handleEqualityComparison(I);
2274 return;
2275 }
2276
2277 assert(I.isRelational())((I.isRelational()) ? static_cast<void> (0) : __assert_fail
("I.isRelational()", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2277, __PRETTY_FUNCTION__))
;
2278 if (ClHandleICmpExact) {
2279 handleRelationalComparisonExact(I);
2280 return;
2281 }
2282 if (I.isSigned()) {
2283 handleSignedRelationalComparison(I);
2284 return;
2285 }
2286
2287 assert(I.isUnsigned())((I.isUnsigned()) ? static_cast<void> (0) : __assert_fail
("I.isUnsigned()", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2287, __PRETTY_FUNCTION__))
;
2288 if ((isa<Constant>(I.getOperand(0)) || isa<Constant>(I.getOperand(1)))) {
2289 handleRelationalComparisonExact(I);
2290 return;
2291 }
2292
2293 handleShadowOr(I);
2294 }
2295
2296 void visitFCmpInst(FCmpInst &I) {
2297 handleShadowOr(I);
2298 }
2299
2300 void handleShift(BinaryOperator &I) {
2301 IRBuilder<> IRB(&I);
2302 // If any of the S2 bits are poisoned, the whole thing is poisoned.
2303 // Otherwise perform the same shift on S1.
2304 Value *S1 = getShadow(&I, 0);
2305 Value *S2 = getShadow(&I, 1);
2306 Value *S2Conv = IRB.CreateSExt(IRB.CreateICmpNE(S2, getCleanShadow(S2)),
2307 S2->getType());
2308 Value *V2 = I.getOperand(1);
2309 Value *Shift = IRB.CreateBinOp(I.getOpcode(), S1, V2);
2310 setShadow(&I, IRB.CreateOr(Shift, S2Conv));
2311 setOriginForNaryOp(I);
2312 }
2313
2314 void visitShl(BinaryOperator &I) { handleShift(I); }
2315 void visitAShr(BinaryOperator &I) { handleShift(I); }
2316 void visitLShr(BinaryOperator &I) { handleShift(I); }
2317
2318 /// Instrument llvm.memmove
2319 ///
2320 /// At this point we don't know if llvm.memmove will be inlined or not.
2321 /// If we don't instrument it and it gets inlined,
2322 /// our interceptor will not kick in and we will lose the memmove.
2323 /// If we instrument the call here, but it does not get inlined,
2324 /// we will memove the shadow twice: which is bad in case
2325 /// of overlapping regions. So, we simply lower the intrinsic to a call.
2326 ///
2327 /// Similar situation exists for memcpy and memset.
2328 void visitMemMoveInst(MemMoveInst &I) {
2329 IRBuilder<> IRB(&I);
2330 IRB.CreateCall(
2331 MS.MemmoveFn,
2332 {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()),
2333 IRB.CreatePointerCast(I.getArgOperand(1), IRB.getInt8PtrTy()),
2334 IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)});
2335 I.eraseFromParent();
2336 }
2337
2338 // Similar to memmove: avoid copying shadow twice.
2339 // This is somewhat unfortunate as it may slowdown small constant memcpys.
2340 // FIXME: consider doing manual inline for small constant sizes and proper
2341 // alignment.
2342 void visitMemCpyInst(MemCpyInst &I) {
2343 IRBuilder<> IRB(&I);
2344 IRB.CreateCall(
2345 MS.MemcpyFn,
2346 {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()),
2347 IRB.CreatePointerCast(I.getArgOperand(1), IRB.getInt8PtrTy()),
2348 IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)});
2349 I.eraseFromParent();
2350 }
2351
2352 // Same as memcpy.
2353 void visitMemSetInst(MemSetInst &I) {
2354 IRBuilder<> IRB(&I);
2355 IRB.CreateCall(
2356 MS.MemsetFn,
2357 {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()),
2358 IRB.CreateIntCast(I.getArgOperand(1), IRB.getInt32Ty(), false),
2359 IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)});
2360 I.eraseFromParent();
2361 }
2362
2363 void visitVAStartInst(VAStartInst &I) {
2364 VAHelper->visitVAStartInst(I);
2365 }
2366
2367 void visitVACopyInst(VACopyInst &I) {
2368 VAHelper->visitVACopyInst(I);
2369 }
2370
2371 /// Handle vector store-like intrinsics.
2372 ///
2373 /// Instrument intrinsics that look like a simple SIMD store: writes memory,
2374 /// has 1 pointer argument and 1 vector argument, returns void.
2375 bool handleVectorStoreIntrinsic(IntrinsicInst &I) {
2376 IRBuilder<> IRB(&I);
2377 Value* Addr = I.getArgOperand(0);
2378 Value *Shadow = getShadow(&I, 1);
2379 Value *ShadowPtr, *OriginPtr;
2380
2381 // We don't know the pointer alignment (could be unaligned SSE store!).
2382 // Have to assume to worst case.
2383 std::tie(ShadowPtr, OriginPtr) = getShadowOriginPtr(
2384 Addr, IRB, Shadow->getType(), /*Alignment*/ 1, /*isStore*/ true);
2385 IRB.CreateAlignedStore(Shadow, ShadowPtr, 1);
2386
2387 if (ClCheckAccessAddress)
2388 insertShadowCheck(Addr, &I);
2389
2390 // FIXME: factor out common code from materializeStores
2391 if (MS.TrackOrigins) IRB.CreateStore(getOrigin(&I, 1), OriginPtr);
2392 return true;
2393 }
2394
2395 /// Handle vector load-like intrinsics.
2396 ///
2397 /// Instrument intrinsics that look like a simple SIMD load: reads memory,
2398 /// has 1 pointer argument, returns a vector.
2399 bool handleVectorLoadIntrinsic(IntrinsicInst &I) {
2400 IRBuilder<> IRB(&I);
2401 Value *Addr = I.getArgOperand(0);
2402
2403 Type *ShadowTy = getShadowTy(&I);
2404 Value *ShadowPtr, *OriginPtr;
10
'OriginPtr' declared without an initial value
2405 if (PropagateShadow) {
11
Assuming the condition is false
12
Taking false branch
2406 // We don't know the pointer alignment (could be unaligned SSE load!).
2407 // Have to assume to worst case.
2408 unsigned Alignment = 1;
2409 std::tie(ShadowPtr, OriginPtr) =
2410 getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ false);
2411 setShadow(&I, IRB.CreateAlignedLoad(ShadowPtr, Alignment, "_msld"));
2412 } else {
2413 setShadow(&I, getCleanShadow(&I));
2414 }
2415
2416 if (ClCheckAccessAddress)
13
Assuming the condition is false
14
Taking false branch
2417 insertShadowCheck(Addr, &I);
2418
2419 if (MS.TrackOrigins) {
15
Assuming the condition is true
16
Taking true branch
2420 if (PropagateShadow)
17
Assuming the condition is true
18
Taking true branch
2421 setOrigin(&I, IRB.CreateLoad(OriginPtr));
19
1st function call argument is an uninitialized value
2422 else
2423 setOrigin(&I, getCleanOrigin());
2424 }
2425 return true;
2426 }
2427
2428 /// Handle (SIMD arithmetic)-like intrinsics.
2429 ///
2430 /// Instrument intrinsics with any number of arguments of the same type,
2431 /// equal to the return type. The type should be simple (no aggregates or
2432 /// pointers; vectors are fine).
2433 /// Caller guarantees that this intrinsic does not access memory.
2434 bool maybeHandleSimpleNomemIntrinsic(IntrinsicInst &I) {
2435 Type *RetTy = I.getType();
2436 if (!(RetTy->isIntOrIntVectorTy() ||
2437 RetTy->isFPOrFPVectorTy() ||
2438 RetTy->isX86_MMXTy()))
2439 return false;
2440
2441 unsigned NumArgOperands = I.getNumArgOperands();
2442
2443 for (unsigned i = 0; i < NumArgOperands; ++i) {
2444 Type *Ty = I.getArgOperand(i)->getType();
2445 if (Ty != RetTy)
2446 return false;
2447 }
2448
2449 IRBuilder<> IRB(&I);
2450 ShadowAndOriginCombiner SC(this, IRB);
2451 for (unsigned i = 0; i < NumArgOperands; ++i)
2452 SC.Add(I.getArgOperand(i));
2453 SC.Done(&I);
2454
2455 return true;
2456 }
2457
2458 /// Heuristically instrument unknown intrinsics.
2459 ///
2460 /// The main purpose of this code is to do something reasonable with all
2461 /// random intrinsics we might encounter, most importantly - SIMD intrinsics.
2462 /// We recognize several classes of intrinsics by their argument types and
2463 /// ModRefBehaviour and apply special intrumentation when we are reasonably
2464 /// sure that we know what the intrinsic does.
2465 ///
2466 /// We special-case intrinsics where this approach fails. See llvm.bswap
2467 /// handling as an example of that.
2468 bool handleUnknownIntrinsic(IntrinsicInst &I) {
2469 unsigned NumArgOperands = I.getNumArgOperands();
2470 if (NumArgOperands == 0)
3
Assuming 'NumArgOperands' is not equal to 0
4
Taking false branch
2471 return false;
2472
2473 if (NumArgOperands == 2 &&
5
Assuming 'NumArgOperands' is not equal to 2
2474 I.getArgOperand(0)->getType()->isPointerTy() &&
2475 I.getArgOperand(1)->getType()->isVectorTy() &&
2476 I.getType()->isVoidTy() &&
2477 !I.onlyReadsMemory()) {
2478 // This looks like a vector store.
2479 return handleVectorStoreIntrinsic(I);
2480 }
2481
2482 if (NumArgOperands == 1 &&
6
Assuming 'NumArgOperands' is equal to 1
8
Taking true branch
2483 I.getArgOperand(0)->getType()->isPointerTy() &&
2484 I.getType()->isVectorTy() &&
2485 I.onlyReadsMemory()) {
7
Assuming the condition is true
2486 // This looks like a vector load.
2487 return handleVectorLoadIntrinsic(I);
9
Calling 'MemorySanitizerVisitor::handleVectorLoadIntrinsic'
2488 }
2489
2490 if (I.doesNotAccessMemory())
2491 if (maybeHandleSimpleNomemIntrinsic(I))
2492 return true;
2493
2494 // FIXME: detect and handle SSE maskstore/maskload
2495 return false;
2496 }
2497
2498 void handleBswap(IntrinsicInst &I) {
2499 IRBuilder<> IRB(&I);
2500 Value *Op = I.getArgOperand(0);
2501 Type *OpType = Op->getType();
2502 Function *BswapFunc = Intrinsic::getDeclaration(
2503 F.getParent(), Intrinsic::bswap, makeArrayRef(&OpType, 1));
2504 setShadow(&I, IRB.CreateCall(BswapFunc, getShadow(Op)));
2505 setOrigin(&I, getOrigin(Op));
2506 }
2507
2508 // Instrument vector convert instrinsic.
2509 //
2510 // This function instruments intrinsics like cvtsi2ss:
2511 // %Out = int_xxx_cvtyyy(%ConvertOp)
2512 // or
2513 // %Out = int_xxx_cvtyyy(%CopyOp, %ConvertOp)
2514 // Intrinsic converts \p NumUsedElements elements of \p ConvertOp to the same
2515 // number \p Out elements, and (if has 2 arguments) copies the rest of the
2516 // elements from \p CopyOp.
2517 // In most cases conversion involves floating-point value which may trigger a
2518 // hardware exception when not fully initialized. For this reason we require
2519 // \p ConvertOp[0:NumUsedElements] to be fully initialized and trap otherwise.
2520 // We copy the shadow of \p CopyOp[NumUsedElements:] to \p
2521 // Out[NumUsedElements:]. This means that intrinsics without \p CopyOp always
2522 // return a fully initialized value.
2523 void handleVectorConvertIntrinsic(IntrinsicInst &I, int NumUsedElements) {
2524 IRBuilder<> IRB(&I);
2525 Value *CopyOp, *ConvertOp;
2526
2527 switch (I.getNumArgOperands()) {
2528 case 3:
2529 assert(isa<ConstantInt>(I.getArgOperand(2)) && "Invalid rounding mode")((isa<ConstantInt>(I.getArgOperand(2)) && "Invalid rounding mode"
) ? static_cast<void> (0) : __assert_fail ("isa<ConstantInt>(I.getArgOperand(2)) && \"Invalid rounding mode\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2529, __PRETTY_FUNCTION__))
;
2530 LLVM_FALLTHROUGH[[clang::fallthrough]];
2531 case 2:
2532 CopyOp = I.getArgOperand(0);
2533 ConvertOp = I.getArgOperand(1);
2534 break;
2535 case 1:
2536 ConvertOp = I.getArgOperand(0);
2537 CopyOp = nullptr;
2538 break;
2539 default:
2540 llvm_unreachable("Cvt intrinsic with unsupported number of arguments.")::llvm::llvm_unreachable_internal("Cvt intrinsic with unsupported number of arguments."
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2540)
;
2541 }
2542
2543 // The first *NumUsedElements* elements of ConvertOp are converted to the
2544 // same number of output elements. The rest of the output is copied from
2545 // CopyOp, or (if not available) filled with zeroes.
2546 // Combine shadow for elements of ConvertOp that are used in this operation,
2547 // and insert a check.
2548 // FIXME: consider propagating shadow of ConvertOp, at least in the case of
2549 // int->any conversion.
2550 Value *ConvertShadow = getShadow(ConvertOp);
2551 Value *AggShadow = nullptr;
2552 if (ConvertOp->getType()->isVectorTy()) {
2553 AggShadow = IRB.CreateExtractElement(
2554 ConvertShadow, ConstantInt::get(IRB.getInt32Ty(), 0));
2555 for (int i = 1; i < NumUsedElements; ++i) {
2556 Value *MoreShadow = IRB.CreateExtractElement(
2557 ConvertShadow, ConstantInt::get(IRB.getInt32Ty(), i));
2558 AggShadow = IRB.CreateOr(AggShadow, MoreShadow);
2559 }
2560 } else {
2561 AggShadow = ConvertShadow;
2562 }
2563 assert(AggShadow->getType()->isIntegerTy())((AggShadow->getType()->isIntegerTy()) ? static_cast<
void> (0) : __assert_fail ("AggShadow->getType()->isIntegerTy()"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2563, __PRETTY_FUNCTION__))
;
2564 insertShadowCheck(AggShadow, getOrigin(ConvertOp), &I);
2565
2566 // Build result shadow by zero-filling parts of CopyOp shadow that come from
2567 // ConvertOp.
2568 if (CopyOp) {
2569 assert(CopyOp->getType() == I.getType())((CopyOp->getType() == I.getType()) ? static_cast<void>
(0) : __assert_fail ("CopyOp->getType() == I.getType()", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2569, __PRETTY_FUNCTION__))
;
2570 assert(CopyOp->getType()->isVectorTy())((CopyOp->getType()->isVectorTy()) ? static_cast<void
> (0) : __assert_fail ("CopyOp->getType()->isVectorTy()"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2570, __PRETTY_FUNCTION__))
;
2571 Value *ResultShadow = getShadow(CopyOp);
2572 Type *EltTy = ResultShadow->getType()->getVectorElementType();
2573 for (int i = 0; i < NumUsedElements; ++i) {
2574 ResultShadow = IRB.CreateInsertElement(
2575 ResultShadow, ConstantInt::getNullValue(EltTy),
2576 ConstantInt::get(IRB.getInt32Ty(), i));
2577 }
2578 setShadow(&I, ResultShadow);
2579 setOrigin(&I, getOrigin(CopyOp));
2580 } else {
2581 setShadow(&I, getCleanShadow(&I));
2582 setOrigin(&I, getCleanOrigin());
2583 }
2584 }
2585
2586 // Given a scalar or vector, extract lower 64 bits (or less), and return all
2587 // zeroes if it is zero, and all ones otherwise.
2588 Value *Lower64ShadowExtend(IRBuilder<> &IRB, Value *S, Type *T) {
2589 if (S->getType()->isVectorTy())
2590 S = CreateShadowCast(IRB, S, IRB.getInt64Ty(), /* Signed */ true);
2591 assert(S->getType()->getPrimitiveSizeInBits() <= 64)((S->getType()->getPrimitiveSizeInBits() <= 64) ? static_cast
<void> (0) : __assert_fail ("S->getType()->getPrimitiveSizeInBits() <= 64"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2591, __PRETTY_FUNCTION__))
;
2592 Value *S2 = IRB.CreateICmpNE(S, getCleanShadow(S));
2593 return CreateShadowCast(IRB, S2, T, /* Signed */ true);
2594 }
2595
2596 // Given a vector, extract its first element, and return all
2597 // zeroes if it is zero, and all ones otherwise.
2598 Value *LowerElementShadowExtend(IRBuilder<> &IRB, Value *S, Type *T) {
2599 Value *S1 = IRB.CreateExtractElement(S, (uint64_t)0);
2600 Value *S2 = IRB.CreateICmpNE(S1, getCleanShadow(S1));
2601 return CreateShadowCast(IRB, S2, T, /* Signed */ true);
2602 }
2603
2604 Value *VariableShadowExtend(IRBuilder<> &IRB, Value *S) {
2605 Type *T = S->getType();
2606 assert(T->isVectorTy())((T->isVectorTy()) ? static_cast<void> (0) : __assert_fail
("T->isVectorTy()", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2606, __PRETTY_FUNCTION__))
;
2607 Value *S2 = IRB.CreateICmpNE(S, getCleanShadow(S));
2608 return IRB.CreateSExt(S2, T);
2609 }
2610
2611 // Instrument vector shift instrinsic.
2612 //
2613 // This function instruments intrinsics like int_x86_avx2_psll_w.
2614 // Intrinsic shifts %In by %ShiftSize bits.
2615 // %ShiftSize may be a vector. In that case the lower 64 bits determine shift
2616 // size, and the rest is ignored. Behavior is defined even if shift size is
2617 // greater than register (or field) width.
2618 void handleVectorShiftIntrinsic(IntrinsicInst &I, bool Variable) {
2619 assert(I.getNumArgOperands() == 2)((I.getNumArgOperands() == 2) ? static_cast<void> (0) :
__assert_fail ("I.getNumArgOperands() == 2", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2619, __PRETTY_FUNCTION__))
;
2620 IRBuilder<> IRB(&I);
2621 // If any of the S2 bits are poisoned, the whole thing is poisoned.
2622 // Otherwise perform the same shift on S1.
2623 Value *S1 = getShadow(&I, 0);
2624 Value *S2 = getShadow(&I, 1);
2625 Value *S2Conv = Variable ? VariableShadowExtend(IRB, S2)
2626 : Lower64ShadowExtend(IRB, S2, getShadowTy(&I));
2627 Value *V1 = I.getOperand(0);
2628 Value *V2 = I.getOperand(1);
2629 Value *Shift = IRB.CreateCall(I.getCalledValue(),
2630 {IRB.CreateBitCast(S1, V1->getType()), V2});
2631 Shift = IRB.CreateBitCast(Shift, getShadowTy(&I));
2632 setShadow(&I, IRB.CreateOr(Shift, S2Conv));
2633 setOriginForNaryOp(I);
2634 }
2635
2636 // Get an X86_MMX-sized vector type.
2637 Type *getMMXVectorTy(unsigned EltSizeInBits) {
2638 const unsigned X86_MMXSizeInBits = 64;
2639 return VectorType::get(IntegerType::get(*MS.C, EltSizeInBits),
2640 X86_MMXSizeInBits / EltSizeInBits);
2641 }
2642
2643 // Returns a signed counterpart for an (un)signed-saturate-and-pack
2644 // intrinsic.
2645 Intrinsic::ID getSignedPackIntrinsic(Intrinsic::ID id) {
2646 switch (id) {
2647 case Intrinsic::x86_sse2_packsswb_128:
2648 case Intrinsic::x86_sse2_packuswb_128:
2649 return Intrinsic::x86_sse2_packsswb_128;
2650
2651 case Intrinsic::x86_sse2_packssdw_128:
2652 case Intrinsic::x86_sse41_packusdw:
2653 return Intrinsic::x86_sse2_packssdw_128;
2654
2655 case Intrinsic::x86_avx2_packsswb:
2656 case Intrinsic::x86_avx2_packuswb:
2657 return Intrinsic::x86_avx2_packsswb;
2658
2659 case Intrinsic::x86_avx2_packssdw:
2660 case Intrinsic::x86_avx2_packusdw:
2661 return Intrinsic::x86_avx2_packssdw;
2662
2663 case Intrinsic::x86_mmx_packsswb:
2664 case Intrinsic::x86_mmx_packuswb:
2665 return Intrinsic::x86_mmx_packsswb;
2666
2667 case Intrinsic::x86_mmx_packssdw:
2668 return Intrinsic::x86_mmx_packssdw;
2669 default:
2670 llvm_unreachable("unexpected intrinsic id")::llvm::llvm_unreachable_internal("unexpected intrinsic id", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2670)
;
2671 }
2672 }
2673
2674 // Instrument vector pack instrinsic.
2675 //
2676 // This function instruments intrinsics like x86_mmx_packsswb, that
2677 // packs elements of 2 input vectors into half as many bits with saturation.
2678 // Shadow is propagated with the signed variant of the same intrinsic applied
2679 // to sext(Sa != zeroinitializer), sext(Sb != zeroinitializer).
2680 // EltSizeInBits is used only for x86mmx arguments.
2681 void handleVectorPackIntrinsic(IntrinsicInst &I, unsigned EltSizeInBits = 0) {
2682 assert(I.getNumArgOperands() == 2)((I.getNumArgOperands() == 2) ? static_cast<void> (0) :
__assert_fail ("I.getNumArgOperands() == 2", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2682, __PRETTY_FUNCTION__))
;
2683 bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy();
2684 IRBuilder<> IRB(&I);
2685 Value *S1 = getShadow(&I, 0);
2686 Value *S2 = getShadow(&I, 1);
2687 assert(isX86_MMX || S1->getType()->isVectorTy())((isX86_MMX || S1->getType()->isVectorTy()) ? static_cast
<void> (0) : __assert_fail ("isX86_MMX || S1->getType()->isVectorTy()"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 2687, __PRETTY_FUNCTION__))
;
2688
2689 // SExt and ICmpNE below must apply to individual elements of input vectors.
2690 // In case of x86mmx arguments, cast them to appropriate vector types and
2691 // back.
2692 Type *T = isX86_MMX ? getMMXVectorTy(EltSizeInBits) : S1->getType();
2693 if (isX86_MMX) {
2694 S1 = IRB.CreateBitCast(S1, T);
2695 S2 = IRB.CreateBitCast(S2, T);
2696 }
2697 Value *S1_ext = IRB.CreateSExt(
2698 IRB.CreateICmpNE(S1, Constant::getNullValue(T)), T);
2699 Value *S2_ext = IRB.CreateSExt(
2700 IRB.CreateICmpNE(S2, Constant::getNullValue(T)), T);
2701 if (isX86_MMX) {
2702 Type *X86_MMXTy = Type::getX86_MMXTy(*MS.C);
2703 S1_ext = IRB.CreateBitCast(S1_ext, X86_MMXTy);
2704 S2_ext = IRB.CreateBitCast(S2_ext, X86_MMXTy);
2705 }
2706
2707 Function *ShadowFn = Intrinsic::getDeclaration(
2708 F.getParent(), getSignedPackIntrinsic(I.getIntrinsicID()));
2709
2710 Value *S =
2711 IRB.CreateCall(ShadowFn, {S1_ext, S2_ext}, "_msprop_vector_pack");
2712 if (isX86_MMX) S = IRB.CreateBitCast(S, getShadowTy(&I));
2713 setShadow(&I, S);
2714 setOriginForNaryOp(I);
2715 }
2716
2717 // Instrument sum-of-absolute-differencies intrinsic.
2718 void handleVectorSadIntrinsic(IntrinsicInst &I) {
2719 const unsigned SignificantBitsPerResultElement = 16;
2720 bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy();
2721 Type *ResTy = isX86_MMX ? IntegerType::get(*MS.C, 64) : I.getType();
2722 unsigned ZeroBitsPerResultElement =
2723 ResTy->getScalarSizeInBits() - SignificantBitsPerResultElement;
2724
2725 IRBuilder<> IRB(&I);
2726 Value *S = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
2727 S = IRB.CreateBitCast(S, ResTy);
2728 S = IRB.CreateSExt(IRB.CreateICmpNE(S, Constant::getNullValue(ResTy)),
2729 ResTy);
2730 S = IRB.CreateLShr(S, ZeroBitsPerResultElement);
2731 S = IRB.CreateBitCast(S, getShadowTy(&I));
2732 setShadow(&I, S);
2733 setOriginForNaryOp(I);
2734 }
2735
2736 // Instrument multiply-add intrinsic.
2737 void handleVectorPmaddIntrinsic(IntrinsicInst &I,
2738 unsigned EltSizeInBits = 0) {
2739 bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy();
2740 Type *ResTy = isX86_MMX ? getMMXVectorTy(EltSizeInBits * 2) : I.getType();
2741 IRBuilder<> IRB(&I);
2742 Value *S = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
2743 S = IRB.CreateBitCast(S, ResTy);
2744 S = IRB.CreateSExt(IRB.CreateICmpNE(S, Constant::getNullValue(ResTy)),
2745 ResTy);
2746 S = IRB.CreateBitCast(S, getShadowTy(&I));
2747 setShadow(&I, S);
2748 setOriginForNaryOp(I);
2749 }
2750
2751 // Instrument compare-packed intrinsic.
2752 // Basically, an or followed by sext(icmp ne 0) to end up with all-zeros or
2753 // all-ones shadow.
2754 void handleVectorComparePackedIntrinsic(IntrinsicInst &I) {
2755 IRBuilder<> IRB(&I);
2756 Type *ResTy = getShadowTy(&I);
2757 Value *S0 = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
2758 Value *S = IRB.CreateSExt(
2759 IRB.CreateICmpNE(S0, Constant::getNullValue(ResTy)), ResTy);
2760 setShadow(&I, S);
2761 setOriginForNaryOp(I);
2762 }
2763
2764 // Instrument compare-scalar intrinsic.
2765 // This handles both cmp* intrinsics which return the result in the first
2766 // element of a vector, and comi* which return the result as i32.
2767 void handleVectorCompareScalarIntrinsic(IntrinsicInst &I) {
2768 IRBuilder<> IRB(&I);
2769 Value *S0 = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1));
2770 Value *S = LowerElementShadowExtend(IRB, S0, getShadowTy(&I));
2771 setShadow(&I, S);
2772 setOriginForNaryOp(I);
2773 }
2774
2775 void handleStmxcsr(IntrinsicInst &I) {
2776 IRBuilder<> IRB(&I);
2777 Value* Addr = I.getArgOperand(0);
2778 Type *Ty = IRB.getInt32Ty();
2779 Value *ShadowPtr =
2780 getShadowOriginPtr(Addr, IRB, Ty, /*Alignment*/ 1, /*isStore*/ true)
2781 .first;
2782
2783 IRB.CreateStore(getCleanShadow(Ty),
2784 IRB.CreatePointerCast(ShadowPtr, Ty->getPointerTo()));
2785
2786 if (ClCheckAccessAddress)
2787 insertShadowCheck(Addr, &I);
2788 }
2789
2790 void handleLdmxcsr(IntrinsicInst &I) {
2791 if (!InsertChecks) return;
2792
2793 IRBuilder<> IRB(&I);
2794 Value *Addr = I.getArgOperand(0);
2795 Type *Ty = IRB.getInt32Ty();
2796 unsigned Alignment = 1;
2797 Value *ShadowPtr, *OriginPtr;
2798 std::tie(ShadowPtr, OriginPtr) =
2799 getShadowOriginPtr(Addr, IRB, Ty, Alignment, /*isStore*/ false);
2800
2801 if (ClCheckAccessAddress)
2802 insertShadowCheck(Addr, &I);
2803
2804 Value *Shadow = IRB.CreateAlignedLoad(ShadowPtr, Alignment, "_ldmxcsr");
2805 Value *Origin =
2806 MS.TrackOrigins ? IRB.CreateLoad(OriginPtr) : getCleanOrigin();
2807 insertShadowCheck(Shadow, Origin, &I);
2808 }
2809
2810 void handleMaskedStore(IntrinsicInst &I) {
2811 IRBuilder<> IRB(&I);
2812 Value *V = I.getArgOperand(0);
2813 Value *Addr = I.getArgOperand(1);
2814 unsigned Align = cast<ConstantInt>(I.getArgOperand(2))->getZExtValue();
2815 Value *Mask = I.getArgOperand(3);
2816 Value *Shadow = getShadow(V);
2817
2818 Value *ShadowPtr;
2819 Value *OriginPtr;
2820 std::tie(ShadowPtr, OriginPtr) = getShadowOriginPtr(
2821 Addr, IRB, Shadow->getType(), Align, /*isStore*/ true);
2822
2823 if (ClCheckAccessAddress) {
2824 insertShadowCheck(Addr, &I);
2825 // Uninitialized mask is kind of like uninitialized address, but not as
2826 // scary.
2827 insertShadowCheck(Mask, &I);
2828 }
2829
2830 IRB.CreateMaskedStore(Shadow, ShadowPtr, Align, Mask);
2831
2832 if (MS.TrackOrigins) {
2833 auto &DL = F.getParent()->getDataLayout();
2834 paintOrigin(IRB, getOrigin(V), OriginPtr,
2835 DL.getTypeStoreSize(Shadow->getType()),
2836 std::max(Align, kMinOriginAlignment));
2837 }
2838 }
2839
2840 bool handleMaskedLoad(IntrinsicInst &I) {
2841 IRBuilder<> IRB(&I);
2842 Value *Addr = I.getArgOperand(0);
2843 unsigned Align = cast<ConstantInt>(I.getArgOperand(1))->getZExtValue();
2844 Value *Mask = I.getArgOperand(2);
2845 Value *PassThru = I.getArgOperand(3);
2846
2847 Type *ShadowTy = getShadowTy(&I);
2848 Value *ShadowPtr, *OriginPtr;
2849 if (PropagateShadow) {
2850 std::tie(ShadowPtr, OriginPtr) =
2851 getShadowOriginPtr(Addr, IRB, ShadowTy, Align, /*isStore*/ false);
2852 setShadow(&I, IRB.CreateMaskedLoad(ShadowPtr, Align, Mask,
2853 getShadow(PassThru), "_msmaskedld"));
2854 } else {
2855 setShadow(&I, getCleanShadow(&I));
2856 }
2857
2858 if (ClCheckAccessAddress) {
2859 insertShadowCheck(Addr, &I);
2860 insertShadowCheck(Mask, &I);
2861 }
2862
2863 if (MS.TrackOrigins) {
2864 if (PropagateShadow) {
2865 // Choose between PassThru's and the loaded value's origins.
2866 Value *MaskedPassThruShadow = IRB.CreateAnd(
2867 getShadow(PassThru), IRB.CreateSExt(IRB.CreateNeg(Mask), ShadowTy));
2868
2869 Value *Acc = IRB.CreateExtractElement(
2870 MaskedPassThruShadow, ConstantInt::get(IRB.getInt32Ty(), 0));
2871 for (int i = 1, N = PassThru->getType()->getVectorNumElements(); i < N;
2872 ++i) {
2873 Value *More = IRB.CreateExtractElement(
2874 MaskedPassThruShadow, ConstantInt::get(IRB.getInt32Ty(), i));
2875 Acc = IRB.CreateOr(Acc, More);
2876 }
2877
2878 Value *Origin = IRB.CreateSelect(
2879 IRB.CreateICmpNE(Acc, Constant::getNullValue(Acc->getType())),
2880 getOrigin(PassThru), IRB.CreateLoad(OriginPtr));
2881
2882 setOrigin(&I, Origin);
2883 } else {
2884 setOrigin(&I, getCleanOrigin());
2885 }
2886 }
2887 return true;
2888 }
2889
2890
2891 void visitIntrinsicInst(IntrinsicInst &I) {
2892 switch (I.getIntrinsicID()) {
1
Control jumps to the 'default' case at line 3106
2893 case Intrinsic::bswap:
2894 handleBswap(I);
2895 break;
2896 case Intrinsic::masked_store:
2897 handleMaskedStore(I);
2898 break;
2899 case Intrinsic::masked_load:
2900 handleMaskedLoad(I);
2901 break;
2902 case Intrinsic::x86_sse_stmxcsr:
2903 handleStmxcsr(I);
2904 break;
2905 case Intrinsic::x86_sse_ldmxcsr:
2906 handleLdmxcsr(I);
2907 break;
2908 case Intrinsic::x86_avx512_vcvtsd2usi64:
2909 case Intrinsic::x86_avx512_vcvtsd2usi32:
2910 case Intrinsic::x86_avx512_vcvtss2usi64:
2911 case Intrinsic::x86_avx512_vcvtss2usi32:
2912 case Intrinsic::x86_avx512_cvttss2usi64:
2913 case Intrinsic::x86_avx512_cvttss2usi:
2914 case Intrinsic::x86_avx512_cvttsd2usi64:
2915 case Intrinsic::x86_avx512_cvttsd2usi:
2916 case Intrinsic::x86_avx512_cvtusi2ss:
2917 case Intrinsic::x86_avx512_cvtusi642sd:
2918 case Intrinsic::x86_avx512_cvtusi642ss:
2919 case Intrinsic::x86_sse2_cvtsd2si64:
2920 case Intrinsic::x86_sse2_cvtsd2si:
2921 case Intrinsic::x86_sse2_cvtsd2ss:
2922 case Intrinsic::x86_sse2_cvttsd2si64:
2923 case Intrinsic::x86_sse2_cvttsd2si:
2924 case Intrinsic::x86_sse_cvtss2si64:
2925 case Intrinsic::x86_sse_cvtss2si:
2926 case Intrinsic::x86_sse_cvttss2si64:
2927 case Intrinsic::x86_sse_cvttss2si:
2928 handleVectorConvertIntrinsic(I, 1);
2929 break;
2930 case Intrinsic::x86_sse_cvtps2pi:
2931 case Intrinsic::x86_sse_cvttps2pi:
2932 handleVectorConvertIntrinsic(I, 2);
2933 break;
2934
2935 case Intrinsic::x86_avx512_psll_w_512:
2936 case Intrinsic::x86_avx512_psll_d_512:
2937 case Intrinsic::x86_avx512_psll_q_512:
2938 case Intrinsic::x86_avx512_pslli_w_512:
2939 case Intrinsic::x86_avx512_pslli_d_512:
2940 case Intrinsic::x86_avx512_pslli_q_512:
2941 case Intrinsic::x86_avx512_psrl_w_512:
2942 case Intrinsic::x86_avx512_psrl_d_512:
2943 case Intrinsic::x86_avx512_psrl_q_512:
2944 case Intrinsic::x86_avx512_psra_w_512:
2945 case Intrinsic::x86_avx512_psra_d_512:
2946 case Intrinsic::x86_avx512_psra_q_512:
2947 case Intrinsic::x86_avx512_psrli_w_512:
2948 case Intrinsic::x86_avx512_psrli_d_512:
2949 case Intrinsic::x86_avx512_psrli_q_512:
2950 case Intrinsic::x86_avx512_psrai_w_512:
2951 case Intrinsic::x86_avx512_psrai_d_512:
2952 case Intrinsic::x86_avx512_psrai_q_512:
2953 case Intrinsic::x86_avx512_psra_q_256:
2954 case Intrinsic::x86_avx512_psra_q_128:
2955 case Intrinsic::x86_avx512_psrai_q_256:
2956 case Intrinsic::x86_avx512_psrai_q_128:
2957 case Intrinsic::x86_avx2_psll_w:
2958 case Intrinsic::x86_avx2_psll_d:
2959 case Intrinsic::x86_avx2_psll_q:
2960 case Intrinsic::x86_avx2_pslli_w:
2961 case Intrinsic::x86_avx2_pslli_d:
2962 case Intrinsic::x86_avx2_pslli_q:
2963 case Intrinsic::x86_avx2_psrl_w:
2964 case Intrinsic::x86_avx2_psrl_d:
2965 case Intrinsic::x86_avx2_psrl_q:
2966 case Intrinsic::x86_avx2_psra_w:
2967 case Intrinsic::x86_avx2_psra_d:
2968 case Intrinsic::x86_avx2_psrli_w:
2969 case Intrinsic::x86_avx2_psrli_d:
2970 case Intrinsic::x86_avx2_psrli_q:
2971 case Intrinsic::x86_avx2_psrai_w:
2972 case Intrinsic::x86_avx2_psrai_d:
2973 case Intrinsic::x86_sse2_psll_w:
2974 case Intrinsic::x86_sse2_psll_d:
2975 case Intrinsic::x86_sse2_psll_q:
2976 case Intrinsic::x86_sse2_pslli_w:
2977 case Intrinsic::x86_sse2_pslli_d:
2978 case Intrinsic::x86_sse2_pslli_q:
2979 case Intrinsic::x86_sse2_psrl_w:
2980 case Intrinsic::x86_sse2_psrl_d:
2981 case Intrinsic::x86_sse2_psrl_q:
2982 case Intrinsic::x86_sse2_psra_w:
2983 case Intrinsic::x86_sse2_psra_d:
2984 case Intrinsic::x86_sse2_psrli_w:
2985 case Intrinsic::x86_sse2_psrli_d:
2986 case Intrinsic::x86_sse2_psrli_q:
2987 case Intrinsic::x86_sse2_psrai_w:
2988 case Intrinsic::x86_sse2_psrai_d:
2989 case Intrinsic::x86_mmx_psll_w:
2990 case Intrinsic::x86_mmx_psll_d:
2991 case Intrinsic::x86_mmx_psll_q:
2992 case Intrinsic::x86_mmx_pslli_w:
2993 case Intrinsic::x86_mmx_pslli_d:
2994 case Intrinsic::x86_mmx_pslli_q:
2995 case Intrinsic::x86_mmx_psrl_w:
2996 case Intrinsic::x86_mmx_psrl_d:
2997 case Intrinsic::x86_mmx_psrl_q:
2998 case Intrinsic::x86_mmx_psra_w:
2999 case Intrinsic::x86_mmx_psra_d:
3000 case Intrinsic::x86_mmx_psrli_w:
3001 case Intrinsic::x86_mmx_psrli_d:
3002 case Intrinsic::x86_mmx_psrli_q:
3003 case Intrinsic::x86_mmx_psrai_w:
3004 case Intrinsic::x86_mmx_psrai_d:
3005 handleVectorShiftIntrinsic(I, /* Variable */ false);
3006 break;
3007 case Intrinsic::x86_avx2_psllv_d:
3008 case Intrinsic::x86_avx2_psllv_d_256:
3009 case Intrinsic::x86_avx512_psllv_d_512:
3010 case Intrinsic::x86_avx2_psllv_q:
3011 case Intrinsic::x86_avx2_psllv_q_256:
3012 case Intrinsic::x86_avx512_psllv_q_512:
3013 case Intrinsic::x86_avx2_psrlv_d:
3014 case Intrinsic::x86_avx2_psrlv_d_256:
3015 case Intrinsic::x86_avx512_psrlv_d_512:
3016 case Intrinsic::x86_avx2_psrlv_q:
3017 case Intrinsic::x86_avx2_psrlv_q_256:
3018 case Intrinsic::x86_avx512_psrlv_q_512:
3019 case Intrinsic::x86_avx2_psrav_d:
3020 case Intrinsic::x86_avx2_psrav_d_256:
3021 case Intrinsic::x86_avx512_psrav_d_512:
3022 case Intrinsic::x86_avx512_psrav_q_128:
3023 case Intrinsic::x86_avx512_psrav_q_256:
3024 case Intrinsic::x86_avx512_psrav_q_512:
3025 handleVectorShiftIntrinsic(I, /* Variable */ true);
3026 break;
3027
3028 case Intrinsic::x86_sse2_packsswb_128:
3029 case Intrinsic::x86_sse2_packssdw_128:
3030 case Intrinsic::x86_sse2_packuswb_128:
3031 case Intrinsic::x86_sse41_packusdw:
3032 case Intrinsic::x86_avx2_packsswb:
3033 case Intrinsic::x86_avx2_packssdw:
3034 case Intrinsic::x86_avx2_packuswb:
3035 case Intrinsic::x86_avx2_packusdw:
3036 handleVectorPackIntrinsic(I);
3037 break;
3038
3039 case Intrinsic::x86_mmx_packsswb:
3040 case Intrinsic::x86_mmx_packuswb:
3041 handleVectorPackIntrinsic(I, 16);
3042 break;
3043
3044 case Intrinsic::x86_mmx_packssdw:
3045 handleVectorPackIntrinsic(I, 32);
3046 break;
3047
3048 case Intrinsic::x86_mmx_psad_bw:
3049 case Intrinsic::x86_sse2_psad_bw:
3050 case Intrinsic::x86_avx2_psad_bw:
3051 handleVectorSadIntrinsic(I);
3052 break;
3053
3054 case Intrinsic::x86_sse2_pmadd_wd:
3055 case Intrinsic::x86_avx2_pmadd_wd:
3056 case Intrinsic::x86_ssse3_pmadd_ub_sw_128:
3057 case Intrinsic::x86_avx2_pmadd_ub_sw:
3058 handleVectorPmaddIntrinsic(I);
3059 break;
3060
3061 case Intrinsic::x86_ssse3_pmadd_ub_sw:
3062 handleVectorPmaddIntrinsic(I, 8);
3063 break;
3064
3065 case Intrinsic::x86_mmx_pmadd_wd:
3066 handleVectorPmaddIntrinsic(I, 16);
3067 break;
3068
3069 case Intrinsic::x86_sse_cmp_ss:
3070 case Intrinsic::x86_sse2_cmp_sd:
3071 case Intrinsic::x86_sse_comieq_ss:
3072 case Intrinsic::x86_sse_comilt_ss:
3073 case Intrinsic::x86_sse_comile_ss:
3074 case Intrinsic::x86_sse_comigt_ss:
3075 case Intrinsic::x86_sse_comige_ss:
3076 case Intrinsic::x86_sse_comineq_ss:
3077 case Intrinsic::x86_sse_ucomieq_ss:
3078 case Intrinsic::x86_sse_ucomilt_ss:
3079 case Intrinsic::x86_sse_ucomile_ss:
3080 case Intrinsic::x86_sse_ucomigt_ss:
3081 case Intrinsic::x86_sse_ucomige_ss:
3082 case Intrinsic::x86_sse_ucomineq_ss:
3083 case Intrinsic::x86_sse2_comieq_sd:
3084 case Intrinsic::x86_sse2_comilt_sd:
3085 case Intrinsic::x86_sse2_comile_sd:
3086 case Intrinsic::x86_sse2_comigt_sd:
3087 case Intrinsic::x86_sse2_comige_sd:
3088 case Intrinsic::x86_sse2_comineq_sd:
3089 case Intrinsic::x86_sse2_ucomieq_sd:
3090 case Intrinsic::x86_sse2_ucomilt_sd:
3091 case Intrinsic::x86_sse2_ucomile_sd:
3092 case Intrinsic::x86_sse2_ucomigt_sd:
3093 case Intrinsic::x86_sse2_ucomige_sd:
3094 case Intrinsic::x86_sse2_ucomineq_sd:
3095 handleVectorCompareScalarIntrinsic(I);
3096 break;
3097
3098 case Intrinsic::x86_sse_cmp_ps:
3099 case Intrinsic::x86_sse2_cmp_pd:
3100 // FIXME: For x86_avx_cmp_pd_256 and x86_avx_cmp_ps_256 this function
3101 // generates reasonably looking IR that fails in the backend with "Do not
3102 // know how to split the result of this operator!".
3103 handleVectorComparePackedIntrinsic(I);
3104 break;
3105
3106 default:
3107 if (!handleUnknownIntrinsic(I))
2
Calling 'MemorySanitizerVisitor::handleUnknownIntrinsic'
3108 visitInstruction(I);
3109 break;
3110 }
3111 }
3112
3113 void visitCallSite(CallSite CS) {
3114 Instruction &I = *CS.getInstruction();
3115 assert(!I.getMetadata("nosanitize"))((!I.getMetadata("nosanitize")) ? static_cast<void> (0)
: __assert_fail ("!I.getMetadata(\"nosanitize\")", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3115, __PRETTY_FUNCTION__))
;
3116 assert((CS.isCall() || CS.isInvoke()) && "Unknown type of CallSite")(((CS.isCall() || CS.isInvoke()) && "Unknown type of CallSite"
) ? static_cast<void> (0) : __assert_fail ("(CS.isCall() || CS.isInvoke()) && \"Unknown type of CallSite\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3116, __PRETTY_FUNCTION__))
;
3117 if (CS.isCall()) {
3118 CallInst *Call = cast<CallInst>(&I);
3119
3120 // For inline asm, do the usual thing: check argument shadow and mark all
3121 // outputs as clean. Note that any side effects of the inline asm that are
3122 // not immediately visible in its constraints are not handled.
3123 if (Call->isInlineAsm()) {
3124 if (ClHandleAsmConservative && MS.CompileKernel)
3125 visitAsmInstruction(I);
3126 else
3127 visitInstruction(I);
3128 return;
3129 }
3130
3131 assert(!isa<IntrinsicInst>(&I) && "intrinsics are handled elsewhere")((!isa<IntrinsicInst>(&I) && "intrinsics are handled elsewhere"
) ? static_cast<void> (0) : __assert_fail ("!isa<IntrinsicInst>(&I) && \"intrinsics are handled elsewhere\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3131, __PRETTY_FUNCTION__))
;
3132
3133 // We are going to insert code that relies on the fact that the callee
3134 // will become a non-readonly function after it is instrumented by us. To
3135 // prevent this code from being optimized out, mark that function
3136 // non-readonly in advance.
3137 if (Function *Func = Call->getCalledFunction()) {
3138 // Clear out readonly/readnone attributes.
3139 AttrBuilder B;
3140 B.addAttribute(Attribute::ReadOnly)
3141 .addAttribute(Attribute::ReadNone);
3142 Func->removeAttributes(AttributeList::FunctionIndex, B);
3143 }
3144
3145 maybeMarkSanitizerLibraryCallNoBuiltin(Call, TLI);
3146 }
3147 IRBuilder<> IRB(&I);
3148
3149 unsigned ArgOffset = 0;
3150 LLVM_DEBUG(dbgs() << " CallSite: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " CallSite: " << I <<
"\n"; } } while (false)
;
3151 for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
3152 ArgIt != End; ++ArgIt) {
3153 Value *A = *ArgIt;
3154 unsigned i = ArgIt - CS.arg_begin();
3155 if (!A->getType()->isSized()) {
3156 LLVM_DEBUG(dbgs() << "Arg " << i << " is not sized: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << "Arg " << i << " is not sized: "
<< I << "\n"; } } while (false)
;
3157 continue;
3158 }
3159 unsigned Size = 0;
3160 Value *Store = nullptr;
3161 // Compute the Shadow for arg even if it is ByVal, because
3162 // in that case getShadow() will copy the actual arg shadow to
3163 // __msan_param_tls.
3164 Value *ArgShadow = getShadow(A);
3165 Value *ArgShadowBase = getShadowPtrForArgument(A, IRB, ArgOffset);
3166 LLVM_DEBUG(dbgs() << " Arg#" << i << ": " << *Ado { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " Arg#" << i << ": "
<< *A << " Shadow: " << *ArgShadow <<
"\n"; } } while (false)
3167 << " Shadow: " << *ArgShadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " Arg#" << i << ": "
<< *A << " Shadow: " << *ArgShadow <<
"\n"; } } while (false)
;
3168 bool ArgIsInitialized = false;
3169 const DataLayout &DL = F.getParent()->getDataLayout();
3170 if (CS.paramHasAttr(i, Attribute::ByVal)) {
3171 assert(A->getType()->isPointerTy() &&((A->getType()->isPointerTy() && "ByVal argument is not a pointer!"
) ? static_cast<void> (0) : __assert_fail ("A->getType()->isPointerTy() && \"ByVal argument is not a pointer!\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3172, __PRETTY_FUNCTION__))
3172 "ByVal argument is not a pointer!")((A->getType()->isPointerTy() && "ByVal argument is not a pointer!"
) ? static_cast<void> (0) : __assert_fail ("A->getType()->isPointerTy() && \"ByVal argument is not a pointer!\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3172, __PRETTY_FUNCTION__))
;
3173 Size = DL.getTypeAllocSize(A->getType()->getPointerElementType());
3174 if (ArgOffset + Size > kParamTLSSize) break;
3175 unsigned ParamAlignment = CS.getParamAlignment(i);
3176 unsigned Alignment = std::min(ParamAlignment, kShadowTLSAlignment);
3177 Value *AShadowPtr =
3178 getShadowOriginPtr(A, IRB, IRB.getInt8Ty(), Alignment,
3179 /*isStore*/ false)
3180 .first;
3181
3182 Store = IRB.CreateMemCpy(ArgShadowBase, Alignment, AShadowPtr,
3183 Alignment, Size);
3184 // TODO(glider): need to copy origins.
3185 } else {
3186 Size = DL.getTypeAllocSize(A->getType());
3187 if (ArgOffset + Size > kParamTLSSize) break;
3188 Store = IRB.CreateAlignedStore(ArgShadow, ArgShadowBase,
3189 kShadowTLSAlignment);
3190 Constant *Cst = dyn_cast<Constant>(ArgShadow);
3191 if (Cst && Cst->isNullValue()) ArgIsInitialized = true;
3192 }
3193 if (MS.TrackOrigins && !ArgIsInitialized)
3194 IRB.CreateStore(getOrigin(A),
3195 getOriginPtrForArgument(A, IRB, ArgOffset));
3196 (void)Store;
3197 assert(Size != 0 && Store != nullptr)((Size != 0 && Store != nullptr) ? static_cast<void
> (0) : __assert_fail ("Size != 0 && Store != nullptr"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3197, __PRETTY_FUNCTION__))
;
3198 LLVM_DEBUG(dbgs() << " Param:" << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " Param:" << *Store <<
"\n"; } } while (false)
;
3199 ArgOffset += alignTo(Size, 8);
3200 }
3201 LLVM_DEBUG(dbgs() << " done with call args\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " done with call args\n"; } } while
(false)
;
3202
3203 FunctionType *FT =
3204 cast<FunctionType>(CS.getCalledValue()->getType()->getContainedType(0));
3205 if (FT->isVarArg()) {
3206 VAHelper->visitCallSite(CS, IRB);
3207 }
3208
3209 // Now, get the shadow for the RetVal.
3210 if (!I.getType()->isSized()) return;
3211 // Don't emit the epilogue for musttail call returns.
3212 if (CS.isCall() && cast<CallInst>(&I)->isMustTailCall()) return;
3213 IRBuilder<> IRBBefore(&I);
3214 // Until we have full dynamic coverage, make sure the retval shadow is 0.
3215 Value *Base = getShadowPtrForRetval(&I, IRBBefore);
3216 IRBBefore.CreateAlignedStore(getCleanShadow(&I), Base, kShadowTLSAlignment);
3217 BasicBlock::iterator NextInsn;
3218 if (CS.isCall()) {
3219 NextInsn = ++I.getIterator();
3220 assert(NextInsn != I.getParent()->end())((NextInsn != I.getParent()->end()) ? static_cast<void>
(0) : __assert_fail ("NextInsn != I.getParent()->end()", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3220, __PRETTY_FUNCTION__))
;
3221 } else {
3222 BasicBlock *NormalDest = cast<InvokeInst>(&I)->getNormalDest();
3223 if (!NormalDest->getSinglePredecessor()) {
3224 // FIXME: this case is tricky, so we are just conservative here.
3225 // Perhaps we need to split the edge between this BB and NormalDest,
3226 // but a naive attempt to use SplitEdge leads to a crash.
3227 setShadow(&I, getCleanShadow(&I));
3228 setOrigin(&I, getCleanOrigin());
3229 return;
3230 }
3231 // FIXME: NextInsn is likely in a basic block that has not been visited yet.
3232 // Anything inserted there will be instrumented by MSan later!
3233 NextInsn = NormalDest->getFirstInsertionPt();
3234 assert(NextInsn != NormalDest->end() &&((NextInsn != NormalDest->end() && "Could not find insertion point for retval shadow load"
) ? static_cast<void> (0) : __assert_fail ("NextInsn != NormalDest->end() && \"Could not find insertion point for retval shadow load\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3235, __PRETTY_FUNCTION__))
3235 "Could not find insertion point for retval shadow load")((NextInsn != NormalDest->end() && "Could not find insertion point for retval shadow load"
) ? static_cast<void> (0) : __assert_fail ("NextInsn != NormalDest->end() && \"Could not find insertion point for retval shadow load\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3235, __PRETTY_FUNCTION__))
;
3236 }
3237 IRBuilder<> IRBAfter(&*NextInsn);
3238 Value *RetvalShadow =
3239 IRBAfter.CreateAlignedLoad(getShadowPtrForRetval(&I, IRBAfter),
3240 kShadowTLSAlignment, "_msret");
3241 setShadow(&I, RetvalShadow);
3242 if (MS.TrackOrigins)
3243 setOrigin(&I, IRBAfter.CreateLoad(getOriginPtrForRetval(IRBAfter)));
3244 }
3245
3246 bool isAMustTailRetVal(Value *RetVal) {
3247 if (auto *I = dyn_cast<BitCastInst>(RetVal)) {
3248 RetVal = I->getOperand(0);
3249 }
3250 if (auto *I = dyn_cast<CallInst>(RetVal)) {
3251 return I->isMustTailCall();
3252 }
3253 return false;
3254 }
3255
3256 void visitReturnInst(ReturnInst &I) {
3257 IRBuilder<> IRB(&I);
3258 Value *RetVal = I.getReturnValue();
3259 if (!RetVal) return;
3260 // Don't emit the epilogue for musttail call returns.
3261 if (isAMustTailRetVal(RetVal)) return;
3262 Value *ShadowPtr = getShadowPtrForRetval(RetVal, IRB);
3263 if (CheckReturnValue) {
3264 insertShadowCheck(RetVal, &I);
3265 Value *Shadow = getCleanShadow(RetVal);
3266 IRB.CreateAlignedStore(Shadow, ShadowPtr, kShadowTLSAlignment);
3267 } else {
3268 Value *Shadow = getShadow(RetVal);
3269 IRB.CreateAlignedStore(Shadow, ShadowPtr, kShadowTLSAlignment);
3270 if (MS.TrackOrigins)
3271 IRB.CreateStore(getOrigin(RetVal), getOriginPtrForRetval(IRB));
3272 }
3273 }
3274
3275 void visitPHINode(PHINode &I) {
3276 IRBuilder<> IRB(&I);
3277 if (!PropagateShadow) {
3278 setShadow(&I, getCleanShadow(&I));
3279 setOrigin(&I, getCleanOrigin());
3280 return;
3281 }
3282
3283 ShadowPHINodes.push_back(&I);
3284 setShadow(&I, IRB.CreatePHI(getShadowTy(&I), I.getNumIncomingValues(),
3285 "_msphi_s"));
3286 if (MS.TrackOrigins)
3287 setOrigin(&I, IRB.CreatePHI(MS.OriginTy, I.getNumIncomingValues(),
3288 "_msphi_o"));
3289 }
3290
3291 Value *getLocalVarDescription(AllocaInst &I) {
3292 SmallString<2048> StackDescriptionStorage;
3293 raw_svector_ostream StackDescription(StackDescriptionStorage);
3294 // We create a string with a description of the stack allocation and
3295 // pass it into __msan_set_alloca_origin.
3296 // It will be printed by the run-time if stack-originated UMR is found.
3297 // The first 4 bytes of the string are set to '----' and will be replaced
3298 // by __msan_va_arg_overflow_size_tls at the first call.
3299 StackDescription << "----" << I.getName() << "@" << F.getName();
3300 return createPrivateNonConstGlobalForString(*F.getParent(),
3301 StackDescription.str());
3302 }
3303
3304 void instrumentAllocaUserspace(AllocaInst &I, IRBuilder<> &IRB, Value *Len) {
3305 if (PoisonStack && ClPoisonStackWithCall) {
3306 IRB.CreateCall(MS.MsanPoisonStackFn,
3307 {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len});
3308 } else {
3309 Value *ShadowBase, *OriginBase;
3310 std::tie(ShadowBase, OriginBase) =
3311 getShadowOriginPtr(&I, IRB, IRB.getInt8Ty(), 1, /*isStore*/ true);
3312
3313 Value *PoisonValue = IRB.getInt8(PoisonStack ? ClPoisonStackPattern : 0);
3314 IRB.CreateMemSet(ShadowBase, PoisonValue, Len, I.getAlignment());
3315 }
3316
3317 if (PoisonStack && MS.TrackOrigins) {
3318 Value *Descr = getLocalVarDescription(I);
3319 IRB.CreateCall(MS.MsanSetAllocaOrigin4Fn,
3320 {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len,
3321 IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy()),
3322 IRB.CreatePointerCast(&F, MS.IntptrTy)});
3323 }
3324 }
3325
3326 void instrumentAllocaKmsan(AllocaInst &I, IRBuilder<> &IRB, Value *Len) {
3327 Value *Descr = getLocalVarDescription(I);
3328 if (PoisonStack) {
3329 IRB.CreateCall(MS.MsanPoisonAllocaFn,
3330 {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len,
3331 IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy())});
3332 } else {
3333 IRB.CreateCall(MS.MsanUnpoisonAllocaFn,
3334 {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len});
3335 }
3336 }
3337
3338 void visitAllocaInst(AllocaInst &I) {
3339 setShadow(&I, getCleanShadow(&I));
3340 setOrigin(&I, getCleanOrigin());
3341 IRBuilder<> IRB(I.getNextNode());
3342 const DataLayout &DL = F.getParent()->getDataLayout();
3343 uint64_t TypeSize = DL.getTypeAllocSize(I.getAllocatedType());
3344 Value *Len = ConstantInt::get(MS.IntptrTy, TypeSize);
3345 if (I.isArrayAllocation())
3346 Len = IRB.CreateMul(Len, I.getArraySize());
3347
3348 if (MS.CompileKernel)
3349 instrumentAllocaKmsan(I, IRB, Len);
3350 else
3351 instrumentAllocaUserspace(I, IRB, Len);
3352 }
3353
3354 void visitSelectInst(SelectInst& I) {
3355 IRBuilder<> IRB(&I);
3356 // a = select b, c, d
3357 Value *B = I.getCondition();
3358 Value *C = I.getTrueValue();
3359 Value *D = I.getFalseValue();
3360 Value *Sb = getShadow(B);
3361 Value *Sc = getShadow(C);
3362 Value *Sd = getShadow(D);
3363
3364 // Result shadow if condition shadow is 0.
3365 Value *Sa0 = IRB.CreateSelect(B, Sc, Sd);
3366 Value *Sa1;
3367 if (I.getType()->isAggregateType()) {
3368 // To avoid "sign extending" i1 to an arbitrary aggregate type, we just do
3369 // an extra "select". This results in much more compact IR.
3370 // Sa = select Sb, poisoned, (select b, Sc, Sd)
3371 Sa1 = getPoisonedShadow(getShadowTy(I.getType()));
3372 } else {
3373 // Sa = select Sb, [ (c^d) | Sc | Sd ], [ b ? Sc : Sd ]
3374 // If Sb (condition is poisoned), look for bits in c and d that are equal
3375 // and both unpoisoned.
3376 // If !Sb (condition is unpoisoned), simply pick one of Sc and Sd.
3377
3378 // Cast arguments to shadow-compatible type.
3379 C = CreateAppToShadowCast(IRB, C);
3380 D = CreateAppToShadowCast(IRB, D);
3381
3382 // Result shadow if condition shadow is 1.
3383 Sa1 = IRB.CreateOr(IRB.CreateXor(C, D), IRB.CreateOr(Sc, Sd));
3384 }
3385 Value *Sa = IRB.CreateSelect(Sb, Sa1, Sa0, "_msprop_select");
3386 setShadow(&I, Sa);
3387 if (MS.TrackOrigins) {
3388 // Origins are always i32, so any vector conditions must be flattened.
3389 // FIXME: consider tracking vector origins for app vectors?
3390 if (B->getType()->isVectorTy()) {
3391 Type *FlatTy = getShadowTyNoVec(B->getType());
3392 B = IRB.CreateICmpNE(IRB.CreateBitCast(B, FlatTy),
3393 ConstantInt::getNullValue(FlatTy));
3394 Sb = IRB.CreateICmpNE(IRB.CreateBitCast(Sb, FlatTy),
3395 ConstantInt::getNullValue(FlatTy));
3396 }
3397 // a = select b, c, d
3398 // Oa = Sb ? Ob : (b ? Oc : Od)
3399 setOrigin(
3400 &I, IRB.CreateSelect(Sb, getOrigin(I.getCondition()),
3401 IRB.CreateSelect(B, getOrigin(I.getTrueValue()),
3402 getOrigin(I.getFalseValue()))));
3403 }
3404 }
3405
3406 void visitLandingPadInst(LandingPadInst &I) {
3407 // Do nothing.
3408 // See https://github.com/google/sanitizers/issues/504
3409 setShadow(&I, getCleanShadow(&I));
3410 setOrigin(&I, getCleanOrigin());
3411 }
3412
3413 void visitCatchSwitchInst(CatchSwitchInst &I) {
3414 setShadow(&I, getCleanShadow(&I));
3415 setOrigin(&I, getCleanOrigin());
3416 }
3417
3418 void visitFuncletPadInst(FuncletPadInst &I) {
3419 setShadow(&I, getCleanShadow(&I));
3420 setOrigin(&I, getCleanOrigin());
3421 }
3422
3423 void visitGetElementPtrInst(GetElementPtrInst &I) {
3424 handleShadowOr(I);
3425 }
3426
3427 void visitExtractValueInst(ExtractValueInst &I) {
3428 IRBuilder<> IRB(&I);
3429 Value *Agg = I.getAggregateOperand();
3430 LLVM_DEBUG(dbgs() << "ExtractValue: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << "ExtractValue: " << I <<
"\n"; } } while (false)
;
3431 Value *AggShadow = getShadow(Agg);
3432 LLVM_DEBUG(dbgs() << " AggShadow: " << *AggShadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " AggShadow: " << *AggShadow
<< "\n"; } } while (false)
;
3433 Value *ResShadow = IRB.CreateExtractValue(AggShadow, I.getIndices());
3434 LLVM_DEBUG(dbgs() << " ResShadow: " << *ResShadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " ResShadow: " << *ResShadow
<< "\n"; } } while (false)
;
3435 setShadow(&I, ResShadow);
3436 setOriginForNaryOp(I);
3437 }
3438
3439 void visitInsertValueInst(InsertValueInst &I) {
3440 IRBuilder<> IRB(&I);
3441 LLVM_DEBUG(dbgs() << "InsertValue: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << "InsertValue: " << I <<
"\n"; } } while (false)
;
3442 Value *AggShadow = getShadow(I.getAggregateOperand());
3443 Value *InsShadow = getShadow(I.getInsertedValueOperand());
3444 LLVM_DEBUG(dbgs() << " AggShadow: " << *AggShadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " AggShadow: " << *AggShadow
<< "\n"; } } while (false)
;
3445 LLVM_DEBUG(dbgs() << " InsShadow: " << *InsShadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " InsShadow: " << *InsShadow
<< "\n"; } } while (false)
;
3446 Value *Res = IRB.CreateInsertValue(AggShadow, InsShadow, I.getIndices());
3447 LLVM_DEBUG(dbgs() << " Res: " << *Res << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << " Res: " << *Res <<
"\n"; } } while (false)
;
3448 setShadow(&I, Res);
3449 setOriginForNaryOp(I);
3450 }
3451
3452 void dumpInst(Instruction &I) {
3453 if (CallInst *CI = dyn_cast<CallInst>(&I)) {
3454 errs() << "ZZZ call " << CI->getCalledFunction()->getName() << "\n";
3455 } else {
3456 errs() << "ZZZ " << I.getOpcodeName() << "\n";
3457 }
3458 errs() << "QQQ " << I << "\n";
3459 }
3460
3461 void visitResumeInst(ResumeInst &I) {
3462 LLVM_DEBUG(dbgs() << "Resume: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << "Resume: " << I << "\n"
; } } while (false)
;
3463 // Nothing to do here.
3464 }
3465
3466 void visitCleanupReturnInst(CleanupReturnInst &CRI) {
3467 LLVM_DEBUG(dbgs() << "CleanupReturn: " << CRI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << "CleanupReturn: " << CRI <<
"\n"; } } while (false)
;
3468 // Nothing to do here.
3469 }
3470
3471 void visitCatchReturnInst(CatchReturnInst &CRI) {
3472 LLVM_DEBUG(dbgs() << "CatchReturn: " << CRI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << "CatchReturn: " << CRI <<
"\n"; } } while (false)
;
3473 // Nothing to do here.
3474 }
3475
3476 void instrumentAsmArgument(Value *Operand, Instruction &I, IRBuilder<> &IRB,
3477 const DataLayout &DL, bool isOutput) {
3478 // For each assembly argument, we check its value for being initialized.
3479 // If the argument is a pointer, we assume it points to a single element
3480 // of the corresponding type (or to a 8-byte word, if the type is unsized).
3481 // Each such pointer is instrumented with a call to the runtime library.
3482 Type *OpType = Operand->getType();
3483 // Check the operand value itself.
3484 insertShadowCheck(Operand, &I);
3485 if (!OpType->isPointerTy()) {
3486 assert(!isOutput)((!isOutput) ? static_cast<void> (0) : __assert_fail ("!isOutput"
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3486, __PRETTY_FUNCTION__))
;
3487 return;
3488 }
3489 Value *Hook =
3490 isOutput ? MS.MsanInstrumentAsmStoreFn : MS.MsanInstrumentAsmLoadFn;
3491 Type *ElType = OpType->getPointerElementType();
3492 if (!ElType->isSized())
3493 return;
3494 int Size = DL.getTypeStoreSize(ElType);
3495 Value *Ptr = IRB.CreatePointerCast(Operand, IRB.getInt8PtrTy());
3496 Value *SizeVal = ConstantInt::get(MS.IntptrTy, Size);
3497 IRB.CreateCall(Hook, {Ptr, SizeVal});
3498 }
3499
3500 /// Get the number of output arguments returned by pointers.
3501 int getNumOutputArgs(InlineAsm *IA, CallInst *CI) {
3502 int NumRetOutputs = 0;
3503 int NumOutputs = 0;
3504 Type *RetTy = dyn_cast<Value>(CI)->getType();
3505 if (!RetTy->isVoidTy()) {
3506 // Register outputs are returned via the CallInst return value.
3507 StructType *ST = dyn_cast_or_null<StructType>(RetTy);
3508 if (ST)
3509 NumRetOutputs = ST->getNumElements();
3510 else
3511 NumRetOutputs = 1;
3512 }
3513 InlineAsm::ConstraintInfoVector Constraints = IA->ParseConstraints();
3514 for (size_t i = 0, n = Constraints.size(); i < n; i++) {
3515 InlineAsm::ConstraintInfo Info = Constraints[i];
3516 switch (Info.Type) {
3517 case InlineAsm::isOutput:
3518 NumOutputs++;
3519 break;
3520 default:
3521 break;
3522 }
3523 }
3524 return NumOutputs - NumRetOutputs;
3525 }
3526
3527 void visitAsmInstruction(Instruction &I) {
3528 // Conservative inline assembly handling: check for poisoned shadow of
3529 // asm() arguments, then unpoison the result and all the memory locations
3530 // pointed to by those arguments.
3531 // An inline asm() statement in C++ contains lists of input and output
3532 // arguments used by the assembly code. These are mapped to operands of the
3533 // CallInst as follows:
3534 // - nR register outputs ("=r) are returned by value in a single structure
3535 // (SSA value of the CallInst);
3536 // - nO other outputs ("=m" and others) are returned by pointer as first
3537 // nO operands of the CallInst;
3538 // - nI inputs ("r", "m" and others) are passed to CallInst as the
3539 // remaining nI operands.
3540 // The total number of asm() arguments in the source is nR+nO+nI, and the
3541 // corresponding CallInst has nO+nI+1 operands (the last operand is the
3542 // function to be called).
3543 const DataLayout &DL = F.getParent()->getDataLayout();
3544 CallInst *CI = dyn_cast<CallInst>(&I);
3545 IRBuilder<> IRB(&I);
3546 InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue());
3547 int OutputArgs = getNumOutputArgs(IA, CI);
3548 // The last operand of a CallInst is the function itself.
3549 int NumOperands = CI->getNumOperands() - 1;
3550
3551 // Check input arguments. Doing so before unpoisoning output arguments, so
3552 // that we won't overwrite uninit values before checking them.
3553 for (int i = OutputArgs; i < NumOperands; i++) {
3554 Value *Operand = CI->getOperand(i);
3555 instrumentAsmArgument(Operand, I, IRB, DL, /*isOutput*/ false);
3556 }
3557 // Unpoison output arguments. This must happen before the actual InlineAsm
3558 // call, so that the shadow for memory published in the asm() statement
3559 // remains valid.
3560 for (int i = 0; i < OutputArgs; i++) {
3561 Value *Operand = CI->getOperand(i);
3562 instrumentAsmArgument(Operand, I, IRB, DL, /*isOutput*/ true);
3563 }
3564
3565 setShadow(&I, getCleanShadow(&I));
3566 setOrigin(&I, getCleanOrigin());
3567 }
3568
3569 void visitInstruction(Instruction &I) {
3570 // Everything else: stop propagating and check for poisoned shadow.
3571 if (ClDumpStrictInstructions)
3572 dumpInst(I);
3573 LLVM_DEBUG(dbgs() << "DEFAULT: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("msan")) { dbgs() << "DEFAULT: " << I << "\n"
; } } while (false)
;
3574 for (size_t i = 0, n = I.getNumOperands(); i < n; i++) {
3575 Value *Operand = I.getOperand(i);
3576 if (Operand->getType()->isSized())
3577 insertShadowCheck(Operand, &I);
3578 }
3579 setShadow(&I, getCleanShadow(&I));
3580 setOrigin(&I, getCleanOrigin());
3581 }
3582};
3583
3584/// AMD64-specific implementation of VarArgHelper.
3585struct VarArgAMD64Helper : public VarArgHelper {
3586 // An unfortunate workaround for asymmetric lowering of va_arg stuff.
3587 // See a comment in visitCallSite for more details.
3588 static const unsigned AMD64GpEndOffset = 48; // AMD64 ABI Draft 0.99.6 p3.5.7
3589 static const unsigned AMD64FpEndOffsetSSE = 176;
3590 // If SSE is disabled, fp_offset in va_list is zero.
3591 static const unsigned AMD64FpEndOffsetNoSSE = AMD64GpEndOffset;
3592
3593 unsigned AMD64FpEndOffset;
3594 Function &F;
3595 MemorySanitizer &MS;
3596 MemorySanitizerVisitor &MSV;
3597 Value *VAArgTLSCopy = nullptr;
3598 Value *VAArgTLSOriginCopy = nullptr;
3599 Value *VAArgOverflowSize = nullptr;
3600
3601 SmallVector<CallInst*, 16> VAStartInstrumentationList;
3602
3603 enum ArgKind { AK_GeneralPurpose, AK_FloatingPoint, AK_Memory };
3604
3605 VarArgAMD64Helper(Function &F, MemorySanitizer &MS,
3606 MemorySanitizerVisitor &MSV)
3607 : F(F), MS(MS), MSV(MSV) {
3608 AMD64FpEndOffset = AMD64FpEndOffsetSSE;
3609 for (const auto &Attr : F.getAttributes().getFnAttributes()) {
3610 if (Attr.isStringAttribute() &&
3611 (Attr.getKindAsString() == "target-features")) {
3612 if (Attr.getValueAsString().contains("-sse"))
3613 AMD64FpEndOffset = AMD64FpEndOffsetNoSSE;
3614 break;
3615 }
3616 }
3617 }
3618
3619 ArgKind classifyArgument(Value* arg) {
3620 // A very rough approximation of X86_64 argument classification rules.
3621 Type *T = arg->getType();
3622 if (T->isFPOrFPVectorTy() || T->isX86_MMXTy())
3623 return AK_FloatingPoint;
3624 if (T->isIntegerTy() && T->getPrimitiveSizeInBits() <= 64)
3625 return AK_GeneralPurpose;
3626 if (T->isPointerTy())
3627 return AK_GeneralPurpose;
3628 return AK_Memory;
3629 }
3630
3631 // For VarArg functions, store the argument shadow in an ABI-specific format
3632 // that corresponds to va_list layout.
3633 // We do this because Clang lowers va_arg in the frontend, and this pass
3634 // only sees the low level code that deals with va_list internals.
3635 // A much easier alternative (provided that Clang emits va_arg instructions)
3636 // would have been to associate each live instance of va_list with a copy of
3637 // MSanParamTLS, and extract shadow on va_arg() call in the argument list
3638 // order.
3639 void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {
3640 unsigned GpOffset = 0;
3641 unsigned FpOffset = AMD64GpEndOffset;
3642 unsigned OverflowOffset = AMD64FpEndOffset;
3643 const DataLayout &DL = F.getParent()->getDataLayout();
3644 for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
3645 ArgIt != End; ++ArgIt) {
3646 Value *A = *ArgIt;
3647 unsigned ArgNo = CS.getArgumentNo(ArgIt);
3648 bool IsFixed = ArgNo < CS.getFunctionType()->getNumParams();
3649 bool IsByVal = CS.paramHasAttr(ArgNo, Attribute::ByVal);
3650 if (IsByVal) {
3651 // ByVal arguments always go to the overflow area.
3652 // Fixed arguments passed through the overflow area will be stepped
3653 // over by va_start, so don't count them towards the offset.
3654 if (IsFixed)
3655 continue;
3656 assert(A->getType()->isPointerTy())((A->getType()->isPointerTy()) ? static_cast<void>
(0) : __assert_fail ("A->getType()->isPointerTy()", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3656, __PRETTY_FUNCTION__))
;
3657 Type *RealTy = A->getType()->getPointerElementType();
3658 uint64_t ArgSize = DL.getTypeAllocSize(RealTy);
3659 Value *ShadowBase = getShadowPtrForVAArgument(
3660 RealTy, IRB, OverflowOffset, alignTo(ArgSize, 8));
3661 Value *OriginBase = nullptr;
3662 if (MS.TrackOrigins)
3663 OriginBase = getOriginPtrForVAArgument(RealTy, IRB, OverflowOffset);
3664 OverflowOffset += alignTo(ArgSize, 8);
3665 if (!ShadowBase)
3666 continue;
3667 Value *ShadowPtr, *OriginPtr;
3668 std::tie(ShadowPtr, OriginPtr) =
3669 MSV.getShadowOriginPtr(A, IRB, IRB.getInt8Ty(), kShadowTLSAlignment,
3670 /*isStore*/ false);
3671
3672 IRB.CreateMemCpy(ShadowBase, kShadowTLSAlignment, ShadowPtr,
3673 kShadowTLSAlignment, ArgSize);
3674 if (MS.TrackOrigins)
3675 IRB.CreateMemCpy(OriginBase, kShadowTLSAlignment, OriginPtr,
3676 kShadowTLSAlignment, ArgSize);
3677 } else {
3678 ArgKind AK = classifyArgument(A);
3679 if (AK == AK_GeneralPurpose && GpOffset >= AMD64GpEndOffset)
3680 AK = AK_Memory;
3681 if (AK == AK_FloatingPoint && FpOffset >= AMD64FpEndOffset)
3682 AK = AK_Memory;
3683 Value *ShadowBase, *OriginBase = nullptr;
3684 switch (AK) {
3685 case AK_GeneralPurpose:
3686 ShadowBase =
3687 getShadowPtrForVAArgument(A->getType(), IRB, GpOffset, 8);
3688 if (MS.TrackOrigins)
3689 OriginBase =
3690 getOriginPtrForVAArgument(A->getType(), IRB, GpOffset);
3691 GpOffset += 8;
3692 break;
3693 case AK_FloatingPoint:
3694 ShadowBase =
3695 getShadowPtrForVAArgument(A->getType(), IRB, FpOffset, 16);
3696 if (MS.TrackOrigins)
3697 OriginBase =
3698 getOriginPtrForVAArgument(A->getType(), IRB, FpOffset);
3699 FpOffset += 16;
3700 break;
3701 case AK_Memory:
3702 if (IsFixed)
3703 continue;
3704 uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
3705 ShadowBase =
3706 getShadowPtrForVAArgument(A->getType(), IRB, OverflowOffset, 8);
3707 if (MS.TrackOrigins)
3708 OriginBase =
3709 getOriginPtrForVAArgument(A->getType(), IRB, OverflowOffset);
3710 OverflowOffset += alignTo(ArgSize, 8);
3711 }
3712 // Take fixed arguments into account for GpOffset and FpOffset,
3713 // but don't actually store shadows for them.
3714 // TODO(glider): don't call get*PtrForVAArgument() for them.
3715 if (IsFixed)
3716 continue;
3717 if (!ShadowBase)
3718 continue;
3719 Value *Shadow = MSV.getShadow(A);
3720 IRB.CreateAlignedStore(Shadow, ShadowBase, kShadowTLSAlignment);
3721 if (MS.TrackOrigins) {
3722 Value *Origin = MSV.getOrigin(A);
3723 unsigned StoreSize = DL.getTypeStoreSize(Shadow->getType());
3724 MSV.paintOrigin(IRB, Origin, OriginBase, StoreSize,
3725 std::max(kShadowTLSAlignment, kMinOriginAlignment));
3726 }
3727 }
3728 }
3729 Constant *OverflowSize =
3730 ConstantInt::get(IRB.getInt64Ty(), OverflowOffset - AMD64FpEndOffset);
3731 IRB.CreateStore(OverflowSize, MS.VAArgOverflowSizeTLS);
3732 }
3733
3734 /// Compute the shadow address for a given va_arg.
3735 Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB,
3736 unsigned ArgOffset, unsigned ArgSize) {
3737 // Make sure we don't overflow __msan_va_arg_tls.
3738 if (ArgOffset + ArgSize > kParamTLSSize)
3739 return nullptr;
3740 Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy);
3741 Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
3742 return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0),
3743 "_msarg_va_s");
3744 }
3745
3746 /// Compute the origin address for a given va_arg.
3747 Value *getOriginPtrForVAArgument(Type *Ty, IRBuilder<> &IRB, int ArgOffset) {
3748 Value *Base = IRB.CreatePointerCast(MS.VAArgOriginTLS, MS.IntptrTy);
3749 // getOriginPtrForVAArgument() is always called after
3750 // getShadowPtrForVAArgument(), so __msan_va_arg_origin_tls can never
3751 // overflow.
3752 Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
3753 return IRB.CreateIntToPtr(Base, PointerType::get(MS.OriginTy, 0),
3754 "_msarg_va_o");
3755 }
3756
3757 void unpoisonVAListTagForInst(IntrinsicInst &I) {
3758 IRBuilder<> IRB(&I);
3759 Value *VAListTag = I.getArgOperand(0);
3760 Value *ShadowPtr, *OriginPtr;
3761 unsigned Alignment = 8;
3762 std::tie(ShadowPtr, OriginPtr) =
3763 MSV.getShadowOriginPtr(VAListTag, IRB, IRB.getInt8Ty(), Alignment,
3764 /*isStore*/ true);
3765
3766 // Unpoison the whole __va_list_tag.
3767 // FIXME: magic ABI constants.
3768 IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
3769 /* size */ 24, Alignment, false);
3770 // We shouldn't need to zero out the origins, as they're only checked for
3771 // nonzero shadow.
3772 }
3773
3774 void visitVAStartInst(VAStartInst &I) override {
3775 if (F.getCallingConv() == CallingConv::Win64)
3776 return;
3777 VAStartInstrumentationList.push_back(&I);
3778 unpoisonVAListTagForInst(I);
3779 }
3780
3781 void visitVACopyInst(VACopyInst &I) override {
3782 if (F.getCallingConv() == CallingConv::Win64) return;
3783 unpoisonVAListTagForInst(I);
3784 }
3785
3786 void finalizeInstrumentation() override {
3787 assert(!VAArgOverflowSize && !VAArgTLSCopy &&((!VAArgOverflowSize && !VAArgTLSCopy && "finalizeInstrumentation called twice"
) ? static_cast<void> (0) : __assert_fail ("!VAArgOverflowSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3788, __PRETTY_FUNCTION__))
3788 "finalizeInstrumentation called twice")((!VAArgOverflowSize && !VAArgTLSCopy && "finalizeInstrumentation called twice"
) ? static_cast<void> (0) : __assert_fail ("!VAArgOverflowSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3788, __PRETTY_FUNCTION__))
;
3789 if (!VAStartInstrumentationList.empty()) {
3790 // If there is a va_start in this function, make a backup copy of
3791 // va_arg_tls somewhere in the function entry block.
3792 IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI());
3793 VAArgOverflowSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS);
3794 Value *CopySize =
3795 IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, AMD64FpEndOffset),
3796 VAArgOverflowSize);
3797 VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
3798 IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize);
3799 if (MS.TrackOrigins) {
3800 VAArgTLSOriginCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
3801 IRB.CreateMemCpy(VAArgTLSOriginCopy, 8, MS.VAArgOriginTLS, 8, CopySize);
3802 }
3803 }
3804
3805 // Instrument va_start.
3806 // Copy va_list shadow from the backup copy of the TLS contents.
3807 for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) {
3808 CallInst *OrigInst = VAStartInstrumentationList[i];
3809 IRBuilder<> IRB(OrigInst->getNextNode());
3810 Value *VAListTag = OrigInst->getArgOperand(0);
3811
3812 Value *RegSaveAreaPtrPtr = IRB.CreateIntToPtr(
3813 IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
3814 ConstantInt::get(MS.IntptrTy, 16)),
3815 PointerType::get(Type::getInt64PtrTy(*MS.C), 0));
3816 Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr);
3817 Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr;
3818 unsigned Alignment = 16;
3819 std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) =
3820 MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(),
3821 Alignment, /*isStore*/ true);
3822 IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment,
3823 AMD64FpEndOffset);
3824 if (MS.TrackOrigins)
3825 IRB.CreateMemCpy(RegSaveAreaOriginPtr, Alignment, VAArgTLSOriginCopy,
3826 Alignment, AMD64FpEndOffset);
3827 Value *OverflowArgAreaPtrPtr = IRB.CreateIntToPtr(
3828 IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
3829 ConstantInt::get(MS.IntptrTy, 8)),
3830 PointerType::get(Type::getInt64PtrTy(*MS.C), 0));
3831 Value *OverflowArgAreaPtr = IRB.CreateLoad(OverflowArgAreaPtrPtr);
3832 Value *OverflowArgAreaShadowPtr, *OverflowArgAreaOriginPtr;
3833 std::tie(OverflowArgAreaShadowPtr, OverflowArgAreaOriginPtr) =
3834 MSV.getShadowOriginPtr(OverflowArgAreaPtr, IRB, IRB.getInt8Ty(),
3835 Alignment, /*isStore*/ true);
3836 Value *SrcPtr = IRB.CreateConstGEP1_32(IRB.getInt8Ty(), VAArgTLSCopy,
3837 AMD64FpEndOffset);
3838 IRB.CreateMemCpy(OverflowArgAreaShadowPtr, Alignment, SrcPtr, Alignment,
3839 VAArgOverflowSize);
3840 if (MS.TrackOrigins) {
3841 SrcPtr = IRB.CreateConstGEP1_32(IRB.getInt8Ty(), VAArgTLSOriginCopy,
3842 AMD64FpEndOffset);
3843 IRB.CreateMemCpy(OverflowArgAreaOriginPtr, Alignment, SrcPtr, Alignment,
3844 VAArgOverflowSize);
3845 }
3846 }
3847 }
3848};
3849
3850/// MIPS64-specific implementation of VarArgHelper.
3851struct VarArgMIPS64Helper : public VarArgHelper {
3852 Function &F;
3853 MemorySanitizer &MS;
3854 MemorySanitizerVisitor &MSV;
3855 Value *VAArgTLSCopy = nullptr;
3856 Value *VAArgSize = nullptr;
3857
3858 SmallVector<CallInst*, 16> VAStartInstrumentationList;
3859
3860 VarArgMIPS64Helper(Function &F, MemorySanitizer &MS,
3861 MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {}
3862
3863 void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {
3864 unsigned VAArgOffset = 0;
3865 const DataLayout &DL = F.getParent()->getDataLayout();
3866 for (CallSite::arg_iterator ArgIt = CS.arg_begin() +
3867 CS.getFunctionType()->getNumParams(), End = CS.arg_end();
3868 ArgIt != End; ++ArgIt) {
3869 Triple TargetTriple(F.getParent()->getTargetTriple());
3870 Value *A = *ArgIt;
3871 Value *Base;
3872 uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
3873 if (TargetTriple.getArch() == Triple::mips64) {
3874 // Adjusting the shadow for argument with size < 8 to match the placement
3875 // of bits in big endian system
3876 if (ArgSize < 8)
3877 VAArgOffset += (8 - ArgSize);
3878 }
3879 Base = getShadowPtrForVAArgument(A->getType(), IRB, VAArgOffset, ArgSize);
3880 VAArgOffset += ArgSize;
3881 VAArgOffset = alignTo(VAArgOffset, 8);
3882 if (!Base)
3883 continue;
3884 IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment);
3885 }
3886
3887 Constant *TotalVAArgSize = ConstantInt::get(IRB.getInt64Ty(), VAArgOffset);
3888 // Here using VAArgOverflowSizeTLS as VAArgSizeTLS to avoid creation of
3889 // a new class member i.e. it is the total size of all VarArgs.
3890 IRB.CreateStore(TotalVAArgSize, MS.VAArgOverflowSizeTLS);
3891 }
3892
3893 /// Compute the shadow address for a given va_arg.
3894 Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB,
3895 unsigned ArgOffset, unsigned ArgSize) {
3896 // Make sure we don't overflow __msan_va_arg_tls.
3897 if (ArgOffset + ArgSize > kParamTLSSize)
3898 return nullptr;
3899 Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy);
3900 Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
3901 return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0),
3902 "_msarg");
3903 }
3904
3905 void visitVAStartInst(VAStartInst &I) override {
3906 IRBuilder<> IRB(&I);
3907 VAStartInstrumentationList.push_back(&I);
3908 Value *VAListTag = I.getArgOperand(0);
3909 Value *ShadowPtr, *OriginPtr;
3910 unsigned Alignment = 8;
3911 std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
3912 VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
3913 IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
3914 /* size */ 8, Alignment, false);
3915 }
3916
3917 void visitVACopyInst(VACopyInst &I) override {
3918 IRBuilder<> IRB(&I);
3919 VAStartInstrumentationList.push_back(&I);
3920 Value *VAListTag = I.getArgOperand(0);
3921 Value *ShadowPtr, *OriginPtr;
3922 unsigned Alignment = 8;
3923 std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
3924 VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
3925 IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
3926 /* size */ 8, Alignment, false);
3927 }
3928
3929 void finalizeInstrumentation() override {
3930 assert(!VAArgSize && !VAArgTLSCopy &&((!VAArgSize && !VAArgTLSCopy && "finalizeInstrumentation called twice"
) ? static_cast<void> (0) : __assert_fail ("!VAArgSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3931, __PRETTY_FUNCTION__))
3931 "finalizeInstrumentation called twice")((!VAArgSize && !VAArgTLSCopy && "finalizeInstrumentation called twice"
) ? static_cast<void> (0) : __assert_fail ("!VAArgSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 3931, __PRETTY_FUNCTION__))
;
3932 IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI());
3933 VAArgSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS);
3934 Value *CopySize = IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, 0),
3935 VAArgSize);
3936
3937 if (!VAStartInstrumentationList.empty()) {
3938 // If there is a va_start in this function, make a backup copy of
3939 // va_arg_tls somewhere in the function entry block.
3940 VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
3941 IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize);
3942 }
3943
3944 // Instrument va_start.
3945 // Copy va_list shadow from the backup copy of the TLS contents.
3946 for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) {
3947 CallInst *OrigInst = VAStartInstrumentationList[i];
3948 IRBuilder<> IRB(OrigInst->getNextNode());
3949 Value *VAListTag = OrigInst->getArgOperand(0);
3950 Value *RegSaveAreaPtrPtr =
3951 IRB.CreateIntToPtr(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
3952 PointerType::get(Type::getInt64PtrTy(*MS.C), 0));
3953 Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr);
3954 Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr;
3955 unsigned Alignment = 8;
3956 std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) =
3957 MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(),
3958 Alignment, /*isStore*/ true);
3959 IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment,
3960 CopySize);
3961 }
3962 }
3963};
3964
3965/// AArch64-specific implementation of VarArgHelper.
3966struct VarArgAArch64Helper : public VarArgHelper {
3967 static const unsigned kAArch64GrArgSize = 64;
3968 static const unsigned kAArch64VrArgSize = 128;
3969
3970 static const unsigned AArch64GrBegOffset = 0;
3971 static const unsigned AArch64GrEndOffset = kAArch64GrArgSize;
3972 // Make VR space aligned to 16 bytes.
3973 static const unsigned AArch64VrBegOffset = AArch64GrEndOffset;
3974 static const unsigned AArch64VrEndOffset = AArch64VrBegOffset
3975 + kAArch64VrArgSize;
3976 static const unsigned AArch64VAEndOffset = AArch64VrEndOffset;
3977
3978 Function &F;
3979 MemorySanitizer &MS;
3980 MemorySanitizerVisitor &MSV;
3981 Value *VAArgTLSCopy = nullptr;
3982 Value *VAArgOverflowSize = nullptr;
3983
3984 SmallVector<CallInst*, 16> VAStartInstrumentationList;
3985
3986 enum ArgKind { AK_GeneralPurpose, AK_FloatingPoint, AK_Memory };
3987
3988 VarArgAArch64Helper(Function &F, MemorySanitizer &MS,
3989 MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {}
3990
3991 ArgKind classifyArgument(Value* arg) {
3992 Type *T = arg->getType();
3993 if (T->isFPOrFPVectorTy())
3994 return AK_FloatingPoint;
3995 if ((T->isIntegerTy() && T->getPrimitiveSizeInBits() <= 64)
3996 || (T->isPointerTy()))
3997 return AK_GeneralPurpose;
3998 return AK_Memory;
3999 }
4000
4001 // The instrumentation stores the argument shadow in a non ABI-specific
4002 // format because it does not know which argument is named (since Clang,
4003 // like x86_64 case, lowers the va_args in the frontend and this pass only
4004 // sees the low level code that deals with va_list internals).
4005 // The first seven GR registers are saved in the first 56 bytes of the
4006 // va_arg tls arra, followers by the first 8 FP/SIMD registers, and then
4007 // the remaining arguments.
4008 // Using constant offset within the va_arg TLS array allows fast copy
4009 // in the finalize instrumentation.
4010 void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {
4011 unsigned GrOffset = AArch64GrBegOffset;
4012 unsigned VrOffset = AArch64VrBegOffset;
4013 unsigned OverflowOffset = AArch64VAEndOffset;
4014
4015 const DataLayout &DL = F.getParent()->getDataLayout();
4016 for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
4017 ArgIt != End; ++ArgIt) {
4018 Value *A = *ArgIt;
4019 unsigned ArgNo = CS.getArgumentNo(ArgIt);
4020 bool IsFixed = ArgNo < CS.getFunctionType()->getNumParams();
4021 ArgKind AK = classifyArgument(A);
4022 if (AK == AK_GeneralPurpose && GrOffset >= AArch64GrEndOffset)
4023 AK = AK_Memory;
4024 if (AK == AK_FloatingPoint && VrOffset >= AArch64VrEndOffset)
4025 AK = AK_Memory;
4026 Value *Base;
4027 switch (AK) {
4028 case AK_GeneralPurpose:
4029 Base = getShadowPtrForVAArgument(A->getType(), IRB, GrOffset, 8);
4030 GrOffset += 8;
4031 break;
4032 case AK_FloatingPoint:
4033 Base = getShadowPtrForVAArgument(A->getType(), IRB, VrOffset, 8);
4034 VrOffset += 16;
4035 break;
4036 case AK_Memory:
4037 // Don't count fixed arguments in the overflow area - va_start will
4038 // skip right over them.
4039 if (IsFixed)
4040 continue;
4041 uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
4042 Base = getShadowPtrForVAArgument(A->getType(), IRB, OverflowOffset,
4043 alignTo(ArgSize, 8));
4044 OverflowOffset += alignTo(ArgSize, 8);
4045 break;
4046 }
4047 // Count Gp/Vr fixed arguments to their respective offsets, but don't
4048 // bother to actually store a shadow.
4049 if (IsFixed)
4050 continue;
4051 if (!Base)
4052 continue;
4053 IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment);
4054 }
4055 Constant *OverflowSize =
4056 ConstantInt::get(IRB.getInt64Ty(), OverflowOffset - AArch64VAEndOffset);
4057 IRB.CreateStore(OverflowSize, MS.VAArgOverflowSizeTLS);
4058 }
4059
4060 /// Compute the shadow address for a given va_arg.
4061 Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB,
4062 unsigned ArgOffset, unsigned ArgSize) {
4063 // Make sure we don't overflow __msan_va_arg_tls.
4064 if (ArgOffset + ArgSize > kParamTLSSize)
4065 return nullptr;
4066 Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy);
4067 Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
4068 return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0),
4069 "_msarg");
4070 }
4071
4072 void visitVAStartInst(VAStartInst &I) override {
4073 IRBuilder<> IRB(&I);
4074 VAStartInstrumentationList.push_back(&I);
4075 Value *VAListTag = I.getArgOperand(0);
4076 Value *ShadowPtr, *OriginPtr;
4077 unsigned Alignment = 8;
4078 std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
4079 VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
4080 IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
4081 /* size */ 32, Alignment, false);
4082 }
4083
4084 void visitVACopyInst(VACopyInst &I) override {
4085 IRBuilder<> IRB(&I);
4086 VAStartInstrumentationList.push_back(&I);
4087 Value *VAListTag = I.getArgOperand(0);
4088 Value *ShadowPtr, *OriginPtr;
4089 unsigned Alignment = 8;
4090 std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
4091 VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
4092 IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
4093 /* size */ 32, Alignment, false);
4094 }
4095
4096 // Retrieve a va_list field of 'void*' size.
4097 Value* getVAField64(IRBuilder<> &IRB, Value *VAListTag, int offset) {
4098 Value *SaveAreaPtrPtr =
4099 IRB.CreateIntToPtr(
4100 IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
4101 ConstantInt::get(MS.IntptrTy, offset)),
4102 Type::getInt64PtrTy(*MS.C));
4103 return IRB.CreateLoad(SaveAreaPtrPtr);
4104 }
4105
4106 // Retrieve a va_list field of 'int' size.
4107 Value* getVAField32(IRBuilder<> &IRB, Value *VAListTag, int offset) {
4108 Value *SaveAreaPtr =
4109 IRB.CreateIntToPtr(
4110 IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
4111 ConstantInt::get(MS.IntptrTy, offset)),
4112 Type::getInt32PtrTy(*MS.C));
4113 Value *SaveArea32 = IRB.CreateLoad(SaveAreaPtr);
4114 return IRB.CreateSExt(SaveArea32, MS.IntptrTy);
4115 }
4116
4117 void finalizeInstrumentation() override {
4118 assert(!VAArgOverflowSize && !VAArgTLSCopy &&((!VAArgOverflowSize && !VAArgTLSCopy && "finalizeInstrumentation called twice"
) ? static_cast<void> (0) : __assert_fail ("!VAArgOverflowSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 4119, __PRETTY_FUNCTION__))
4119 "finalizeInstrumentation called twice")((!VAArgOverflowSize && !VAArgTLSCopy && "finalizeInstrumentation called twice"
) ? static_cast<void> (0) : __assert_fail ("!VAArgOverflowSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 4119, __PRETTY_FUNCTION__))
;
4120 if (!VAStartInstrumentationList.empty()) {
4121 // If there is a va_start in this function, make a backup copy of
4122 // va_arg_tls somewhere in the function entry block.
4123 IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI());
4124 VAArgOverflowSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS);
4125 Value *CopySize =
4126 IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, AArch64VAEndOffset),
4127 VAArgOverflowSize);
4128 VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
4129 IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize);
4130 }
4131
4132 Value *GrArgSize = ConstantInt::get(MS.IntptrTy, kAArch64GrArgSize);
4133 Value *VrArgSize = ConstantInt::get(MS.IntptrTy, kAArch64VrArgSize);
4134
4135 // Instrument va_start, copy va_list shadow from the backup copy of
4136 // the TLS contents.
4137 for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) {
4138 CallInst *OrigInst = VAStartInstrumentationList[i];
4139 IRBuilder<> IRB(OrigInst->getNextNode());
4140
4141 Value *VAListTag = OrigInst->getArgOperand(0);
4142
4143 // The variadic ABI for AArch64 creates two areas to save the incoming
4144 // argument registers (one for 64-bit general register xn-x7 and another
4145 // for 128-bit FP/SIMD vn-v7).
4146 // We need then to propagate the shadow arguments on both regions
4147 // 'va::__gr_top + va::__gr_offs' and 'va::__vr_top + va::__vr_offs'.
4148 // The remaning arguments are saved on shadow for 'va::stack'.
4149 // One caveat is it requires only to propagate the non-named arguments,
4150 // however on the call site instrumentation 'all' the arguments are
4151 // saved. So to copy the shadow values from the va_arg TLS array
4152 // we need to adjust the offset for both GR and VR fields based on
4153 // the __{gr,vr}_offs value (since they are stores based on incoming
4154 // named arguments).
4155
4156 // Read the stack pointer from the va_list.
4157 Value *StackSaveAreaPtr = getVAField64(IRB, VAListTag, 0);
4158
4159 // Read both the __gr_top and __gr_off and add them up.
4160 Value *GrTopSaveAreaPtr = getVAField64(IRB, VAListTag, 8);
4161 Value *GrOffSaveArea = getVAField32(IRB, VAListTag, 24);
4162
4163 Value *GrRegSaveAreaPtr = IRB.CreateAdd(GrTopSaveAreaPtr, GrOffSaveArea);
4164
4165 // Read both the __vr_top and __vr_off and add them up.
4166 Value *VrTopSaveAreaPtr = getVAField64(IRB, VAListTag, 16);
4167 Value *VrOffSaveArea = getVAField32(IRB, VAListTag, 28);
4168
4169 Value *VrRegSaveAreaPtr = IRB.CreateAdd(VrTopSaveAreaPtr, VrOffSaveArea);
4170
4171 // It does not know how many named arguments is being used and, on the
4172 // callsite all the arguments were saved. Since __gr_off is defined as
4173 // '0 - ((8 - named_gr) * 8)', the idea is to just propagate the variadic
4174 // argument by ignoring the bytes of shadow from named arguments.
4175 Value *GrRegSaveAreaShadowPtrOff =
4176 IRB.CreateAdd(GrArgSize, GrOffSaveArea);
4177
4178 Value *GrRegSaveAreaShadowPtr =
4179 MSV.getShadowOriginPtr(GrRegSaveAreaPtr, IRB, IRB.getInt8Ty(),
4180 /*Alignment*/ 8, /*isStore*/ true)
4181 .first;
4182
4183 Value *GrSrcPtr = IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy,
4184 GrRegSaveAreaShadowPtrOff);
4185 Value *GrCopySize = IRB.CreateSub(GrArgSize, GrRegSaveAreaShadowPtrOff);
4186
4187 IRB.CreateMemCpy(GrRegSaveAreaShadowPtr, 8, GrSrcPtr, 8, GrCopySize);
4188
4189 // Again, but for FP/SIMD values.
4190 Value *VrRegSaveAreaShadowPtrOff =
4191 IRB.CreateAdd(VrArgSize, VrOffSaveArea);
4192
4193 Value *VrRegSaveAreaShadowPtr =
4194 MSV.getShadowOriginPtr(VrRegSaveAreaPtr, IRB, IRB.getInt8Ty(),
4195 /*Alignment*/ 8, /*isStore*/ true)
4196 .first;
4197
4198 Value *VrSrcPtr = IRB.CreateInBoundsGEP(
4199 IRB.getInt8Ty(),
4200 IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy,
4201 IRB.getInt32(AArch64VrBegOffset)),
4202 VrRegSaveAreaShadowPtrOff);
4203 Value *VrCopySize = IRB.CreateSub(VrArgSize, VrRegSaveAreaShadowPtrOff);
4204
4205 IRB.CreateMemCpy(VrRegSaveAreaShadowPtr, 8, VrSrcPtr, 8, VrCopySize);
4206
4207 // And finally for remaining arguments.
4208 Value *StackSaveAreaShadowPtr =
4209 MSV.getShadowOriginPtr(StackSaveAreaPtr, IRB, IRB.getInt8Ty(),
4210 /*Alignment*/ 16, /*isStore*/ true)
4211 .first;
4212
4213 Value *StackSrcPtr =
4214 IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy,
4215 IRB.getInt32(AArch64VAEndOffset));
4216
4217 IRB.CreateMemCpy(StackSaveAreaShadowPtr, 16, StackSrcPtr, 16,
4218 VAArgOverflowSize);
4219 }
4220 }
4221};
4222
4223/// PowerPC64-specific implementation of VarArgHelper.
4224struct VarArgPowerPC64Helper : public VarArgHelper {
4225 Function &F;
4226 MemorySanitizer &MS;
4227 MemorySanitizerVisitor &MSV;
4228 Value *VAArgTLSCopy = nullptr;
4229 Value *VAArgSize = nullptr;
4230
4231 SmallVector<CallInst*, 16> VAStartInstrumentationList;
4232
4233 VarArgPowerPC64Helper(Function &F, MemorySanitizer &MS,
4234 MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {}
4235
4236 void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {
4237 // For PowerPC, we need to deal with alignment of stack arguments -
4238 // they are mostly aligned to 8 bytes, but vectors and i128 arrays
4239 // are aligned to 16 bytes, byvals can be aligned to 8 or 16 bytes,
4240 // and QPX vectors are aligned to 32 bytes. For that reason, we
4241 // compute current offset from stack pointer (which is always properly
4242 // aligned), and offset for the first vararg, then subtract them.
4243 unsigned VAArgBase;
4244 Triple TargetTriple(F.getParent()->getTargetTriple());
4245 // Parameter save area starts at 48 bytes from frame pointer for ABIv1,
4246 // and 32 bytes for ABIv2. This is usually determined by target
4247 // endianness, but in theory could be overriden by function attribute.
4248 // For simplicity, we ignore it here (it'd only matter for QPX vectors).
4249 if (TargetTriple.getArch() == Triple::ppc64)
4250 VAArgBase = 48;
4251 else
4252 VAArgBase = 32;
4253 unsigned VAArgOffset = VAArgBase;
4254 const DataLayout &DL = F.getParent()->getDataLayout();
4255 for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end();
4256 ArgIt != End; ++ArgIt) {
4257 Value *A = *ArgIt;
4258 unsigned ArgNo = CS.getArgumentNo(ArgIt);
4259 bool IsFixed = ArgNo < CS.getFunctionType()->getNumParams();
4260 bool IsByVal = CS.paramHasAttr(ArgNo, Attribute::ByVal);
4261 if (IsByVal) {
4262 assert(A->getType()->isPointerTy())((A->getType()->isPointerTy()) ? static_cast<void>
(0) : __assert_fail ("A->getType()->isPointerTy()", "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 4262, __PRETTY_FUNCTION__))
;
4263 Type *RealTy = A->getType()->getPointerElementType();
4264 uint64_t ArgSize = DL.getTypeAllocSize(RealTy);
4265 uint64_t ArgAlign = CS.getParamAlignment(ArgNo);
4266 if (ArgAlign < 8)
4267 ArgAlign = 8;
4268 VAArgOffset = alignTo(VAArgOffset, ArgAlign);
4269 if (!IsFixed) {
4270 Value *Base = getShadowPtrForVAArgument(
4271 RealTy, IRB, VAArgOffset - VAArgBase, ArgSize);
4272 if (Base) {
4273 Value *AShadowPtr, *AOriginPtr;
4274 std::tie(AShadowPtr, AOriginPtr) =
4275 MSV.getShadowOriginPtr(A, IRB, IRB.getInt8Ty(),
4276 kShadowTLSAlignment, /*isStore*/ false);
4277
4278 IRB.CreateMemCpy(Base, kShadowTLSAlignment, AShadowPtr,
4279 kShadowTLSAlignment, ArgSize);
4280 }
4281 }
4282 VAArgOffset += alignTo(ArgSize, 8);
4283 } else {
4284 Value *Base;
4285 uint64_t ArgSize = DL.getTypeAllocSize(A->getType());
4286 uint64_t ArgAlign = 8;
4287 if (A->getType()->isArrayTy()) {
4288 // Arrays are aligned to element size, except for long double
4289 // arrays, which are aligned to 8 bytes.
4290 Type *ElementTy = A->getType()->getArrayElementType();
4291 if (!ElementTy->isPPC_FP128Ty())
4292 ArgAlign = DL.getTypeAllocSize(ElementTy);
4293 } else if (A->getType()->isVectorTy()) {
4294 // Vectors are naturally aligned.
4295 ArgAlign = DL.getTypeAllocSize(A->getType());
4296 }
4297 if (ArgAlign < 8)
4298 ArgAlign = 8;
4299 VAArgOffset = alignTo(VAArgOffset, ArgAlign);
4300 if (DL.isBigEndian()) {
4301 // Adjusting the shadow for argument with size < 8 to match the placement
4302 // of bits in big endian system
4303 if (ArgSize < 8)
4304 VAArgOffset += (8 - ArgSize);
4305 }
4306 if (!IsFixed) {
4307 Base = getShadowPtrForVAArgument(A->getType(), IRB,
4308 VAArgOffset - VAArgBase, ArgSize);
4309 if (Base)
4310 IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment);
4311 }
4312 VAArgOffset += ArgSize;
4313 VAArgOffset = alignTo(VAArgOffset, 8);
4314 }
4315 if (IsFixed)
4316 VAArgBase = VAArgOffset;
4317 }
4318
4319 Constant *TotalVAArgSize = ConstantInt::get(IRB.getInt64Ty(),
4320 VAArgOffset - VAArgBase);
4321 // Here using VAArgOverflowSizeTLS as VAArgSizeTLS to avoid creation of
4322 // a new class member i.e. it is the total size of all VarArgs.
4323 IRB.CreateStore(TotalVAArgSize, MS.VAArgOverflowSizeTLS);
4324 }
4325
4326 /// Compute the shadow address for a given va_arg.
4327 Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB,
4328 unsigned ArgOffset, unsigned ArgSize) {
4329 // Make sure we don't overflow __msan_va_arg_tls.
4330 if (ArgOffset + ArgSize > kParamTLSSize)
4331 return nullptr;
4332 Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy);
4333 Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset));
4334 return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0),
4335 "_msarg");
4336 }
4337
4338 void visitVAStartInst(VAStartInst &I) override {
4339 IRBuilder<> IRB(&I);
4340 VAStartInstrumentationList.push_back(&I);
4341 Value *VAListTag = I.getArgOperand(0);
4342 Value *ShadowPtr, *OriginPtr;
4343 unsigned Alignment = 8;
4344 std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
4345 VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
4346 IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
4347 /* size */ 8, Alignment, false);
4348 }
4349
4350 void visitVACopyInst(VACopyInst &I) override {
4351 IRBuilder<> IRB(&I);
4352 Value *VAListTag = I.getArgOperand(0);
4353 Value *ShadowPtr, *OriginPtr;
4354 unsigned Alignment = 8;
4355 std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr(
4356 VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true);
4357 // Unpoison the whole __va_list_tag.
4358 // FIXME: magic ABI constants.
4359 IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()),
4360 /* size */ 8, Alignment, false);
4361 }
4362
4363 void finalizeInstrumentation() override {
4364 assert(!VAArgSize && !VAArgTLSCopy &&((!VAArgSize && !VAArgTLSCopy && "finalizeInstrumentation called twice"
) ? static_cast<void> (0) : __assert_fail ("!VAArgSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 4365, __PRETTY_FUNCTION__))
4365 "finalizeInstrumentation called twice")((!VAArgSize && !VAArgTLSCopy && "finalizeInstrumentation called twice"
) ? static_cast<void> (0) : __assert_fail ("!VAArgSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\""
, "/build/llvm-toolchain-snapshot-8~svn348900/lib/Transforms/Instrumentation/MemorySanitizer.cpp"
, 4365, __PRETTY_FUNCTION__))
;
4366 IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI());
4367 VAArgSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS);
4368 Value *CopySize = IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, 0),
4369 VAArgSize);
4370
4371 if (!VAStartInstrumentationList.empty()) {
4372 // If there is a va_start in this function, make a backup copy of
4373 // va_arg_tls somewhere in the function entry block.
4374 VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize);
4375 IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize);
4376 }
4377
4378 // Instrument va_start.
4379 // Copy va_list shadow from the backup copy of the TLS contents.
4380 for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) {
4381 CallInst *OrigInst = VAStartInstrumentationList[i];
4382 IRBuilder<> IRB(OrigInst->getNextNode());
4383 Value *VAListTag = OrigInst->getArgOperand(0);
4384 Value *RegSaveAreaPtrPtr =
4385 IRB.CreateIntToPtr(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy),
4386 PointerType::get(Type::getInt64PtrTy(*MS.C), 0));
4387 Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr);
4388 Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr;
4389 unsigned Alignment = 8;
4390 std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) =
4391 MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(),
4392 Alignment, /*isStore*/ true);
4393 IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment,
4394 CopySize);
4395 }
4396 }
4397};
4398
4399/// A no-op implementation of VarArgHelper.
4400struct VarArgNoOpHelper : public VarArgHelper {
4401 VarArgNoOpHelper(Function &F, MemorySanitizer &MS,
4402 MemorySanitizerVisitor &MSV) {}
4403
4404 void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {}
4405
4406 void visitVAStartInst(VAStartInst &I) override {}
4407
4408 void visitVACopyInst(VACopyInst &I) override {}
4409
4410 void finalizeInstrumentation() override {}
4411};
4412
4413} // end anonymous namespace
4414
4415static VarArgHelper *CreateVarArgHelper(Function &Func, MemorySanitizer &Msan,
4416 MemorySanitizerVisitor &Visitor) {
4417 // VarArg handling is only implemented on AMD64. False positives are possible
4418 // on other platforms.
4419 Triple TargetTriple(Func.getParent()->getTargetTriple());
4420 if (TargetTriple.getArch() == Triple::x86_64)
4421 return new VarArgAMD64Helper(Func, Msan, Visitor);
4422 else if (TargetTriple.isMIPS64())
4423 return new VarArgMIPS64Helper(Func, Msan, Visitor);
4424 else if (TargetTriple.getArch() == Triple::aarch64)
4425 return new VarArgAArch64Helper(Func, Msan, Visitor);
4426 else if (TargetTriple.getArch() == Triple::ppc64 ||
4427 TargetTriple.getArch() == Triple::ppc64le)
4428 return new VarArgPowerPC64Helper(Func, Msan, Visitor);
4429 else
4430 return new VarArgNoOpHelper(Func, Msan, Visitor);
4431}
4432
4433bool MemorySanitizer::runOnFunction(Function &F) {
4434 if (!CompileKernel && (&F == MsanCtorFunction))
4435 return false;
4436 MemorySanitizerVisitor Visitor(F, *this);
4437
4438 // Clear out readonly/readnone attributes.
4439 AttrBuilder B;
4440 B.addAttribute(Attribute::ReadOnly)
4441 .addAttribute(Attribute::ReadNone);
4442 F.removeAttributes(AttributeList::FunctionIndex, B);
4443
4444 return Visitor.runOnFunction();
4445}