File: | src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp |
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1 | //===- MemorySanitizer.cpp - detector of uninitialized reads --------------===// | |||
2 | // | |||
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | |||
4 | // See https://llvm.org/LICENSE.txt for license information. | |||
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |||
6 | // | |||
7 | //===----------------------------------------------------------------------===// | |||
8 | // | |||
9 | /// \file | |||
10 | /// This file is a part of MemorySanitizer, a detector of uninitialized | |||
11 | /// reads. | |||
12 | /// | |||
13 | /// The algorithm of the tool is similar to Memcheck | |||
14 | /// (http://goo.gl/QKbem). We associate a few shadow bits with every | |||
15 | /// byte of the application memory, poison the shadow of the malloc-ed | |||
16 | /// or alloca-ed memory, load the shadow bits on every memory read, | |||
17 | /// propagate the shadow bits through some of the arithmetic | |||
18 | /// instruction (including MOV), store the shadow bits on every memory | |||
19 | /// write, report a bug on some other instructions (e.g. JMP) if the | |||
20 | /// associated shadow is poisoned. | |||
21 | /// | |||
22 | /// But there are differences too. The first and the major one: | |||
23 | /// compiler instrumentation instead of binary instrumentation. This | |||
24 | /// gives us much better register allocation, possible compiler | |||
25 | /// optimizations and a fast start-up. But this brings the major issue | |||
26 | /// as well: msan needs to see all program events, including system | |||
27 | /// calls and reads/writes in system libraries, so we either need to | |||
28 | /// compile *everything* with msan or use a binary translation | |||
29 | /// component (e.g. DynamoRIO) to instrument pre-built libraries. | |||
30 | /// Another difference from Memcheck is that we use 8 shadow bits per | |||
31 | /// byte of application memory and use a direct shadow mapping. This | |||
32 | /// greatly simplifies the instrumentation code and avoids races on | |||
33 | /// shadow updates (Memcheck is single-threaded so races are not a | |||
34 | /// concern there. Memcheck uses 2 shadow bits per byte with a slow | |||
35 | /// path storage that uses 8 bits per byte). | |||
36 | /// | |||
37 | /// The default value of shadow is 0, which means "clean" (not poisoned). | |||
38 | /// | |||
39 | /// Every module initializer should call __msan_init to ensure that the | |||
40 | /// shadow memory is ready. On error, __msan_warning is called. Since | |||
41 | /// parameters and return values may be passed via registers, we have a | |||
42 | /// specialized thread-local shadow for return values | |||
43 | /// (__msan_retval_tls) and parameters (__msan_param_tls). | |||
44 | /// | |||
45 | /// Origin tracking. | |||
46 | /// | |||
47 | /// MemorySanitizer can track origins (allocation points) of all uninitialized | |||
48 | /// values. This behavior is controlled with a flag (msan-track-origins) and is | |||
49 | /// disabled by default. | |||
50 | /// | |||
51 | /// Origins are 4-byte values created and interpreted by the runtime library. | |||
52 | /// They are stored in a second shadow mapping, one 4-byte value for 4 bytes | |||
53 | /// of application memory. Propagation of origins is basically a bunch of | |||
54 | /// "select" instructions that pick the origin of a dirty argument, if an | |||
55 | /// instruction has one. | |||
56 | /// | |||
57 | /// Every 4 aligned, consecutive bytes of application memory have one origin | |||
58 | /// value associated with them. If these bytes contain uninitialized data | |||
59 | /// coming from 2 different allocations, the last store wins. Because of this, | |||
60 | /// MemorySanitizer reports can show unrelated origins, but this is unlikely in | |||
61 | /// practice. | |||
62 | /// | |||
63 | /// Origins are meaningless for fully initialized values, so MemorySanitizer | |||
64 | /// avoids storing origin to memory when a fully initialized value is stored. | |||
65 | /// This way it avoids needless overwriting origin of the 4-byte region on | |||
66 | /// a short (i.e. 1 byte) clean store, and it is also good for performance. | |||
67 | /// | |||
68 | /// Atomic handling. | |||
69 | /// | |||
70 | /// Ideally, every atomic store of application value should update the | |||
71 | /// corresponding shadow location in an atomic way. Unfortunately, atomic store | |||
72 | /// of two disjoint locations can not be done without severe slowdown. | |||
73 | /// | |||
74 | /// Therefore, we implement an approximation that may err on the safe side. | |||
75 | /// In this implementation, every atomically accessed location in the program | |||
76 | /// may only change from (partially) uninitialized to fully initialized, but | |||
77 | /// not the other way around. We load the shadow _after_ the application load, | |||
78 | /// and we store the shadow _before_ the app store. Also, we always store clean | |||
79 | /// shadow (if the application store is atomic). This way, if the store-load | |||
80 | /// pair constitutes a happens-before arc, shadow store and load are correctly | |||
81 | /// ordered such that the load will get either the value that was stored, or | |||
82 | /// some later value (which is always clean). | |||
83 | /// | |||
84 | /// This does not work very well with Compare-And-Swap (CAS) and | |||
85 | /// Read-Modify-Write (RMW) operations. To follow the above logic, CAS and RMW | |||
86 | /// must store the new shadow before the app operation, and load the shadow | |||
87 | /// after the app operation. Computers don't work this way. Current | |||
88 | /// implementation ignores the load aspect of CAS/RMW, always returning a clean | |||
89 | /// value. It implements the store part as a simple atomic store by storing a | |||
90 | /// clean shadow. | |||
91 | /// | |||
92 | /// Instrumenting inline assembly. | |||
93 | /// | |||
94 | /// For inline assembly code LLVM has little idea about which memory locations | |||
95 | /// become initialized depending on the arguments. It can be possible to figure | |||
96 | /// out which arguments are meant to point to inputs and outputs, but the | |||
97 | /// actual semantics can be only visible at runtime. In the Linux kernel it's | |||
98 | /// also possible that the arguments only indicate the offset for a base taken | |||
99 | /// from a segment register, so it's dangerous to treat any asm() arguments as | |||
100 | /// pointers. We take a conservative approach generating calls to | |||
101 | /// __msan_instrument_asm_store(ptr, size) | |||
102 | /// , which defer the memory unpoisoning to the runtime library. | |||
103 | /// The latter can perform more complex address checks to figure out whether | |||
104 | /// it's safe to touch the shadow memory. | |||
105 | /// Like with atomic operations, we call __msan_instrument_asm_store() before | |||
106 | /// the assembly call, so that changes to the shadow memory will be seen by | |||
107 | /// other threads together with main memory initialization. | |||
108 | /// | |||
109 | /// KernelMemorySanitizer (KMSAN) implementation. | |||
110 | /// | |||
111 | /// The major differences between KMSAN and MSan instrumentation are: | |||
112 | /// - KMSAN always tracks the origins and implies msan-keep-going=true; | |||
113 | /// - KMSAN allocates shadow and origin memory for each page separately, so | |||
114 | /// there are no explicit accesses to shadow and origin in the | |||
115 | /// instrumentation. | |||
116 | /// Shadow and origin values for a particular X-byte memory location | |||
117 | /// (X=1,2,4,8) are accessed through pointers obtained via the | |||
118 | /// __msan_metadata_ptr_for_load_X(ptr) | |||
119 | /// __msan_metadata_ptr_for_store_X(ptr) | |||
120 | /// functions. The corresponding functions check that the X-byte accesses | |||
121 | /// are possible and returns the pointers to shadow and origin memory. | |||
122 | /// Arbitrary sized accesses are handled with: | |||
123 | /// __msan_metadata_ptr_for_load_n(ptr, size) | |||
124 | /// __msan_metadata_ptr_for_store_n(ptr, size); | |||
125 | /// - TLS variables are stored in a single per-task struct. A call to a | |||
126 | /// function __msan_get_context_state() returning a pointer to that struct | |||
127 | /// is inserted into every instrumented function before the entry block; | |||
128 | /// - __msan_warning() takes a 32-bit origin parameter; | |||
129 | /// - local variables are poisoned with __msan_poison_alloca() upon function | |||
130 | /// entry and unpoisoned with __msan_unpoison_alloca() before leaving the | |||
131 | /// function; | |||
132 | /// - the pass doesn't declare any global variables or add global constructors | |||
133 | /// to the translation unit. | |||
134 | /// | |||
135 | /// Also, KMSAN currently ignores uninitialized memory passed into inline asm | |||
136 | /// calls, making sure we're on the safe side wrt. possible false positives. | |||
137 | /// | |||
138 | /// KernelMemorySanitizer only supports X86_64 at the moment. | |||
139 | /// | |||
140 | // | |||
141 | // FIXME: This sanitizer does not yet handle scalable vectors | |||
142 | // | |||
143 | //===----------------------------------------------------------------------===// | |||
144 | ||||
145 | #include "llvm/Transforms/Instrumentation/MemorySanitizer.h" | |||
146 | #include "llvm/ADT/APInt.h" | |||
147 | #include "llvm/ADT/ArrayRef.h" | |||
148 | #include "llvm/ADT/DepthFirstIterator.h" | |||
149 | #include "llvm/ADT/SmallSet.h" | |||
150 | #include "llvm/ADT/SmallString.h" | |||
151 | #include "llvm/ADT/SmallVector.h" | |||
152 | #include "llvm/ADT/StringExtras.h" | |||
153 | #include "llvm/ADT/StringRef.h" | |||
154 | #include "llvm/ADT/Triple.h" | |||
155 | #include "llvm/Analysis/TargetLibraryInfo.h" | |||
156 | #include "llvm/Analysis/ValueTracking.h" | |||
157 | #include "llvm/IR/Argument.h" | |||
158 | #include "llvm/IR/Attributes.h" | |||
159 | #include "llvm/IR/BasicBlock.h" | |||
160 | #include "llvm/IR/CallingConv.h" | |||
161 | #include "llvm/IR/Constant.h" | |||
162 | #include "llvm/IR/Constants.h" | |||
163 | #include "llvm/IR/DataLayout.h" | |||
164 | #include "llvm/IR/DerivedTypes.h" | |||
165 | #include "llvm/IR/Function.h" | |||
166 | #include "llvm/IR/GlobalValue.h" | |||
167 | #include "llvm/IR/GlobalVariable.h" | |||
168 | #include "llvm/IR/IRBuilder.h" | |||
169 | #include "llvm/IR/InlineAsm.h" | |||
170 | #include "llvm/IR/InstVisitor.h" | |||
171 | #include "llvm/IR/InstrTypes.h" | |||
172 | #include "llvm/IR/Instruction.h" | |||
173 | #include "llvm/IR/Instructions.h" | |||
174 | #include "llvm/IR/IntrinsicInst.h" | |||
175 | #include "llvm/IR/Intrinsics.h" | |||
176 | #include "llvm/IR/IntrinsicsX86.h" | |||
177 | #include "llvm/IR/LLVMContext.h" | |||
178 | #include "llvm/IR/MDBuilder.h" | |||
179 | #include "llvm/IR/Module.h" | |||
180 | #include "llvm/IR/Type.h" | |||
181 | #include "llvm/IR/Value.h" | |||
182 | #include "llvm/IR/ValueMap.h" | |||
183 | #include "llvm/InitializePasses.h" | |||
184 | #include "llvm/Pass.h" | |||
185 | #include "llvm/Support/AtomicOrdering.h" | |||
186 | #include "llvm/Support/Casting.h" | |||
187 | #include "llvm/Support/CommandLine.h" | |||
188 | #include "llvm/Support/Compiler.h" | |||
189 | #include "llvm/Support/Debug.h" | |||
190 | #include "llvm/Support/ErrorHandling.h" | |||
191 | #include "llvm/Support/MathExtras.h" | |||
192 | #include "llvm/Support/raw_ostream.h" | |||
193 | #include "llvm/Transforms/Instrumentation.h" | |||
194 | #include "llvm/Transforms/Utils/BasicBlockUtils.h" | |||
195 | #include "llvm/Transforms/Utils/Local.h" | |||
196 | #include "llvm/Transforms/Utils/ModuleUtils.h" | |||
197 | #include <algorithm> | |||
198 | #include <cassert> | |||
199 | #include <cstddef> | |||
200 | #include <cstdint> | |||
201 | #include <memory> | |||
202 | #include <string> | |||
203 | #include <tuple> | |||
204 | ||||
205 | using namespace llvm; | |||
206 | ||||
207 | #define DEBUG_TYPE"msan" "msan" | |||
208 | ||||
209 | static const unsigned kOriginSize = 4; | |||
210 | static const Align kMinOriginAlignment = Align(4); | |||
211 | static const Align kShadowTLSAlignment = Align(8); | |||
212 | ||||
213 | // These constants must be kept in sync with the ones in msan.h. | |||
214 | static const unsigned kParamTLSSize = 800; | |||
215 | static const unsigned kRetvalTLSSize = 800; | |||
216 | ||||
217 | // Accesses sizes are powers of two: 1, 2, 4, 8. | |||
218 | static const size_t kNumberOfAccessSizes = 4; | |||
219 | ||||
220 | /// Track origins of uninitialized values. | |||
221 | /// | |||
222 | /// Adds a section to MemorySanitizer report that points to the allocation | |||
223 | /// (stack or heap) the uninitialized bits came from originally. | |||
224 | static cl::opt<int> ClTrackOrigins("msan-track-origins", | |||
225 | cl::desc("Track origins (allocation sites) of poisoned memory"), | |||
226 | cl::Hidden, cl::init(0)); | |||
227 | ||||
228 | static cl::opt<bool> ClKeepGoing("msan-keep-going", | |||
229 | cl::desc("keep going after reporting a UMR"), | |||
230 | cl::Hidden, cl::init(false)); | |||
231 | ||||
232 | static cl::opt<bool> ClPoisonStack("msan-poison-stack", | |||
233 | cl::desc("poison uninitialized stack variables"), | |||
234 | cl::Hidden, cl::init(true)); | |||
235 | ||||
236 | static cl::opt<bool> ClPoisonStackWithCall("msan-poison-stack-with-call", | |||
237 | cl::desc("poison uninitialized stack variables with a call"), | |||
238 | cl::Hidden, cl::init(false)); | |||
239 | ||||
240 | static cl::opt<int> ClPoisonStackPattern("msan-poison-stack-pattern", | |||
241 | cl::desc("poison uninitialized stack variables with the given pattern"), | |||
242 | cl::Hidden, cl::init(0xff)); | |||
243 | ||||
244 | static cl::opt<bool> ClPoisonUndef("msan-poison-undef", | |||
245 | cl::desc("poison undef temps"), | |||
246 | cl::Hidden, cl::init(true)); | |||
247 | ||||
248 | static cl::opt<bool> ClHandleICmp("msan-handle-icmp", | |||
249 | cl::desc("propagate shadow through ICmpEQ and ICmpNE"), | |||
250 | cl::Hidden, cl::init(true)); | |||
251 | ||||
252 | static cl::opt<bool> ClHandleICmpExact("msan-handle-icmp-exact", | |||
253 | cl::desc("exact handling of relational integer ICmp"), | |||
254 | cl::Hidden, cl::init(false)); | |||
255 | ||||
256 | static cl::opt<bool> ClHandleLifetimeIntrinsics( | |||
257 | "msan-handle-lifetime-intrinsics", | |||
258 | cl::desc( | |||
259 | "when possible, poison scoped variables at the beginning of the scope " | |||
260 | "(slower, but more precise)"), | |||
261 | cl::Hidden, cl::init(true)); | |||
262 | ||||
263 | // When compiling the Linux kernel, we sometimes see false positives related to | |||
264 | // MSan being unable to understand that inline assembly calls may initialize | |||
265 | // local variables. | |||
266 | // This flag makes the compiler conservatively unpoison every memory location | |||
267 | // passed into an assembly call. Note that this may cause false positives. | |||
268 | // Because it's impossible to figure out the array sizes, we can only unpoison | |||
269 | // the first sizeof(type) bytes for each type* pointer. | |||
270 | // The instrumentation is only enabled in KMSAN builds, and only if | |||
271 | // -msan-handle-asm-conservative is on. This is done because we may want to | |||
272 | // quickly disable assembly instrumentation when it breaks. | |||
273 | static cl::opt<bool> ClHandleAsmConservative( | |||
274 | "msan-handle-asm-conservative", | |||
275 | cl::desc("conservative handling of inline assembly"), cl::Hidden, | |||
276 | cl::init(true)); | |||
277 | ||||
278 | // This flag controls whether we check the shadow of the address | |||
279 | // operand of load or store. Such bugs are very rare, since load from | |||
280 | // a garbage address typically results in SEGV, but still happen | |||
281 | // (e.g. only lower bits of address are garbage, or the access happens | |||
282 | // early at program startup where malloc-ed memory is more likely to | |||
283 | // be zeroed. As of 2012-08-28 this flag adds 20% slowdown. | |||
284 | static cl::opt<bool> ClCheckAccessAddress("msan-check-access-address", | |||
285 | cl::desc("report accesses through a pointer which has poisoned shadow"), | |||
286 | cl::Hidden, cl::init(true)); | |||
287 | ||||
288 | static cl::opt<bool> ClEagerChecks( | |||
289 | "msan-eager-checks", | |||
290 | cl::desc("check arguments and return values at function call boundaries"), | |||
291 | cl::Hidden, cl::init(false)); | |||
292 | ||||
293 | static cl::opt<bool> ClDumpStrictInstructions("msan-dump-strict-instructions", | |||
294 | cl::desc("print out instructions with default strict semantics"), | |||
295 | cl::Hidden, cl::init(false)); | |||
296 | ||||
297 | static cl::opt<int> ClInstrumentationWithCallThreshold( | |||
298 | "msan-instrumentation-with-call-threshold", | |||
299 | cl::desc( | |||
300 | "If the function being instrumented requires more than " | |||
301 | "this number of checks and origin stores, use callbacks instead of " | |||
302 | "inline checks (-1 means never use callbacks)."), | |||
303 | cl::Hidden, cl::init(3500)); | |||
304 | ||||
305 | static cl::opt<bool> | |||
306 | ClEnableKmsan("msan-kernel", | |||
307 | cl::desc("Enable KernelMemorySanitizer instrumentation"), | |||
308 | cl::Hidden, cl::init(false)); | |||
309 | ||||
310 | // This is an experiment to enable handling of cases where shadow is a non-zero | |||
311 | // compile-time constant. For some unexplainable reason they were silently | |||
312 | // ignored in the instrumentation. | |||
313 | static cl::opt<bool> ClCheckConstantShadow("msan-check-constant-shadow", | |||
314 | cl::desc("Insert checks for constant shadow values"), | |||
315 | cl::Hidden, cl::init(false)); | |||
316 | ||||
317 | // This is off by default because of a bug in gold: | |||
318 | // https://sourceware.org/bugzilla/show_bug.cgi?id=19002 | |||
319 | static cl::opt<bool> ClWithComdat("msan-with-comdat", | |||
320 | cl::desc("Place MSan constructors in comdat sections"), | |||
321 | cl::Hidden, cl::init(false)); | |||
322 | ||||
323 | // These options allow to specify custom memory map parameters | |||
324 | // See MemoryMapParams for details. | |||
325 | static cl::opt<uint64_t> ClAndMask("msan-and-mask", | |||
326 | cl::desc("Define custom MSan AndMask"), | |||
327 | cl::Hidden, cl::init(0)); | |||
328 | ||||
329 | static cl::opt<uint64_t> ClXorMask("msan-xor-mask", | |||
330 | cl::desc("Define custom MSan XorMask"), | |||
331 | cl::Hidden, cl::init(0)); | |||
332 | ||||
333 | static cl::opt<uint64_t> ClShadowBase("msan-shadow-base", | |||
334 | cl::desc("Define custom MSan ShadowBase"), | |||
335 | cl::Hidden, cl::init(0)); | |||
336 | ||||
337 | static cl::opt<uint64_t> ClOriginBase("msan-origin-base", | |||
338 | cl::desc("Define custom MSan OriginBase"), | |||
339 | cl::Hidden, cl::init(0)); | |||
340 | ||||
341 | const char kMsanModuleCtorName[] = "msan.module_ctor"; | |||
342 | const char kMsanInitName[] = "__msan_init"; | |||
343 | ||||
344 | namespace { | |||
345 | ||||
346 | // Memory map parameters used in application-to-shadow address calculation. | |||
347 | // Offset = (Addr & ~AndMask) ^ XorMask | |||
348 | // Shadow = ShadowBase + Offset | |||
349 | // Origin = OriginBase + Offset | |||
350 | struct MemoryMapParams { | |||
351 | uint64_t AndMask; | |||
352 | uint64_t XorMask; | |||
353 | uint64_t ShadowBase; | |||
354 | uint64_t OriginBase; | |||
355 | }; | |||
356 | ||||
357 | struct PlatformMemoryMapParams { | |||
358 | const MemoryMapParams *bits32; | |||
359 | const MemoryMapParams *bits64; | |||
360 | }; | |||
361 | ||||
362 | } // end anonymous namespace | |||
363 | ||||
364 | // i386 Linux | |||
365 | static const MemoryMapParams Linux_I386_MemoryMapParams = { | |||
366 | 0x000080000000, // AndMask | |||
367 | 0, // XorMask (not used) | |||
368 | 0, // ShadowBase (not used) | |||
369 | 0x000040000000, // OriginBase | |||
370 | }; | |||
371 | ||||
372 | // x86_64 Linux | |||
373 | static const MemoryMapParams Linux_X86_64_MemoryMapParams = { | |||
374 | #ifdef MSAN_LINUX_X86_64_OLD_MAPPING | |||
375 | 0x400000000000, // AndMask | |||
376 | 0, // XorMask (not used) | |||
377 | 0, // ShadowBase (not used) | |||
378 | 0x200000000000, // OriginBase | |||
379 | #else | |||
380 | 0, // AndMask (not used) | |||
381 | 0x500000000000, // XorMask | |||
382 | 0, // ShadowBase (not used) | |||
383 | 0x100000000000, // OriginBase | |||
384 | #endif | |||
385 | }; | |||
386 | ||||
387 | // mips64 Linux | |||
388 | static const MemoryMapParams Linux_MIPS64_MemoryMapParams = { | |||
389 | 0, // AndMask (not used) | |||
390 | 0x008000000000, // XorMask | |||
391 | 0, // ShadowBase (not used) | |||
392 | 0x002000000000, // OriginBase | |||
393 | }; | |||
394 | ||||
395 | // ppc64 Linux | |||
396 | static const MemoryMapParams Linux_PowerPC64_MemoryMapParams = { | |||
397 | 0xE00000000000, // AndMask | |||
398 | 0x100000000000, // XorMask | |||
399 | 0x080000000000, // ShadowBase | |||
400 | 0x1C0000000000, // OriginBase | |||
401 | }; | |||
402 | ||||
403 | // s390x Linux | |||
404 | static const MemoryMapParams Linux_S390X_MemoryMapParams = { | |||
405 | 0xC00000000000, // AndMask | |||
406 | 0, // XorMask (not used) | |||
407 | 0x080000000000, // ShadowBase | |||
408 | 0x1C0000000000, // OriginBase | |||
409 | }; | |||
410 | ||||
411 | // aarch64 Linux | |||
412 | static const MemoryMapParams Linux_AArch64_MemoryMapParams = { | |||
413 | 0, // AndMask (not used) | |||
414 | 0x06000000000, // XorMask | |||
415 | 0, // ShadowBase (not used) | |||
416 | 0x01000000000, // OriginBase | |||
417 | }; | |||
418 | ||||
419 | // i386 FreeBSD | |||
420 | static const MemoryMapParams FreeBSD_I386_MemoryMapParams = { | |||
421 | 0x000180000000, // AndMask | |||
422 | 0x000040000000, // XorMask | |||
423 | 0x000020000000, // ShadowBase | |||
424 | 0x000700000000, // OriginBase | |||
425 | }; | |||
426 | ||||
427 | // x86_64 FreeBSD | |||
428 | static const MemoryMapParams FreeBSD_X86_64_MemoryMapParams = { | |||
429 | 0xc00000000000, // AndMask | |||
430 | 0x200000000000, // XorMask | |||
431 | 0x100000000000, // ShadowBase | |||
432 | 0x380000000000, // OriginBase | |||
433 | }; | |||
434 | ||||
435 | // x86_64 NetBSD | |||
436 | static const MemoryMapParams NetBSD_X86_64_MemoryMapParams = { | |||
437 | 0, // AndMask | |||
438 | 0x500000000000, // XorMask | |||
439 | 0, // ShadowBase | |||
440 | 0x100000000000, // OriginBase | |||
441 | }; | |||
442 | ||||
443 | static const PlatformMemoryMapParams Linux_X86_MemoryMapParams = { | |||
444 | &Linux_I386_MemoryMapParams, | |||
445 | &Linux_X86_64_MemoryMapParams, | |||
446 | }; | |||
447 | ||||
448 | static const PlatformMemoryMapParams Linux_MIPS_MemoryMapParams = { | |||
449 | nullptr, | |||
450 | &Linux_MIPS64_MemoryMapParams, | |||
451 | }; | |||
452 | ||||
453 | static const PlatformMemoryMapParams Linux_PowerPC_MemoryMapParams = { | |||
454 | nullptr, | |||
455 | &Linux_PowerPC64_MemoryMapParams, | |||
456 | }; | |||
457 | ||||
458 | static const PlatformMemoryMapParams Linux_S390_MemoryMapParams = { | |||
459 | nullptr, | |||
460 | &Linux_S390X_MemoryMapParams, | |||
461 | }; | |||
462 | ||||
463 | static const PlatformMemoryMapParams Linux_ARM_MemoryMapParams = { | |||
464 | nullptr, | |||
465 | &Linux_AArch64_MemoryMapParams, | |||
466 | }; | |||
467 | ||||
468 | static const PlatformMemoryMapParams FreeBSD_X86_MemoryMapParams = { | |||
469 | &FreeBSD_I386_MemoryMapParams, | |||
470 | &FreeBSD_X86_64_MemoryMapParams, | |||
471 | }; | |||
472 | ||||
473 | static const PlatformMemoryMapParams NetBSD_X86_MemoryMapParams = { | |||
474 | nullptr, | |||
475 | &NetBSD_X86_64_MemoryMapParams, | |||
476 | }; | |||
477 | ||||
478 | namespace { | |||
479 | ||||
480 | /// Instrument functions of a module to detect uninitialized reads. | |||
481 | /// | |||
482 | /// Instantiating MemorySanitizer inserts the msan runtime library API function | |||
483 | /// declarations into the module if they don't exist already. Instantiating | |||
484 | /// ensures the __msan_init function is in the list of global constructors for | |||
485 | /// the module. | |||
486 | class MemorySanitizer { | |||
487 | public: | |||
488 | MemorySanitizer(Module &M, MemorySanitizerOptions Options) | |||
489 | : CompileKernel(Options.Kernel), TrackOrigins(Options.TrackOrigins), | |||
490 | Recover(Options.Recover) { | |||
491 | initializeModule(M); | |||
492 | } | |||
493 | ||||
494 | // MSan cannot be moved or copied because of MapParams. | |||
495 | MemorySanitizer(MemorySanitizer &&) = delete; | |||
496 | MemorySanitizer &operator=(MemorySanitizer &&) = delete; | |||
497 | MemorySanitizer(const MemorySanitizer &) = delete; | |||
498 | MemorySanitizer &operator=(const MemorySanitizer &) = delete; | |||
499 | ||||
500 | bool sanitizeFunction(Function &F, TargetLibraryInfo &TLI); | |||
501 | ||||
502 | private: | |||
503 | friend struct MemorySanitizerVisitor; | |||
504 | friend struct VarArgAMD64Helper; | |||
505 | friend struct VarArgMIPS64Helper; | |||
506 | friend struct VarArgAArch64Helper; | |||
507 | friend struct VarArgPowerPC64Helper; | |||
508 | friend struct VarArgSystemZHelper; | |||
509 | ||||
510 | void initializeModule(Module &M); | |||
511 | void initializeCallbacks(Module &M); | |||
512 | void createKernelApi(Module &M); | |||
513 | void createUserspaceApi(Module &M); | |||
514 | ||||
515 | /// True if we're compiling the Linux kernel. | |||
516 | bool CompileKernel; | |||
517 | /// Track origins (allocation points) of uninitialized values. | |||
518 | int TrackOrigins; | |||
519 | bool Recover; | |||
520 | ||||
521 | LLVMContext *C; | |||
522 | Type *IntptrTy; | |||
523 | Type *OriginTy; | |||
524 | ||||
525 | // XxxTLS variables represent the per-thread state in MSan and per-task state | |||
526 | // in KMSAN. | |||
527 | // For the userspace these point to thread-local globals. In the kernel land | |||
528 | // they point to the members of a per-task struct obtained via a call to | |||
529 | // __msan_get_context_state(). | |||
530 | ||||
531 | /// Thread-local shadow storage for function parameters. | |||
532 | Value *ParamTLS; | |||
533 | ||||
534 | /// Thread-local origin storage for function parameters. | |||
535 | Value *ParamOriginTLS; | |||
536 | ||||
537 | /// Thread-local shadow storage for function return value. | |||
538 | Value *RetvalTLS; | |||
539 | ||||
540 | /// Thread-local origin storage for function return value. | |||
541 | Value *RetvalOriginTLS; | |||
542 | ||||
543 | /// Thread-local shadow storage for in-register va_arg function | |||
544 | /// parameters (x86_64-specific). | |||
545 | Value *VAArgTLS; | |||
546 | ||||
547 | /// Thread-local shadow storage for in-register va_arg function | |||
548 | /// parameters (x86_64-specific). | |||
549 | Value *VAArgOriginTLS; | |||
550 | ||||
551 | /// Thread-local shadow storage for va_arg overflow area | |||
552 | /// (x86_64-specific). | |||
553 | Value *VAArgOverflowSizeTLS; | |||
554 | ||||
555 | /// Are the instrumentation callbacks set up? | |||
556 | bool CallbacksInitialized = false; | |||
557 | ||||
558 | /// The run-time callback to print a warning. | |||
559 | FunctionCallee WarningFn; | |||
560 | ||||
561 | // These arrays are indexed by log2(AccessSize). | |||
562 | FunctionCallee MaybeWarningFn[kNumberOfAccessSizes]; | |||
563 | FunctionCallee MaybeStoreOriginFn[kNumberOfAccessSizes]; | |||
564 | ||||
565 | /// Run-time helper that generates a new origin value for a stack | |||
566 | /// allocation. | |||
567 | FunctionCallee MsanSetAllocaOrigin4Fn; | |||
568 | ||||
569 | /// Run-time helper that poisons stack on function entry. | |||
570 | FunctionCallee MsanPoisonStackFn; | |||
571 | ||||
572 | /// Run-time helper that records a store (or any event) of an | |||
573 | /// uninitialized value and returns an updated origin id encoding this info. | |||
574 | FunctionCallee MsanChainOriginFn; | |||
575 | ||||
576 | /// Run-time helper that paints an origin over a region. | |||
577 | FunctionCallee MsanSetOriginFn; | |||
578 | ||||
579 | /// MSan runtime replacements for memmove, memcpy and memset. | |||
580 | FunctionCallee MemmoveFn, MemcpyFn, MemsetFn; | |||
581 | ||||
582 | /// KMSAN callback for task-local function argument shadow. | |||
583 | StructType *MsanContextStateTy; | |||
584 | FunctionCallee MsanGetContextStateFn; | |||
585 | ||||
586 | /// Functions for poisoning/unpoisoning local variables | |||
587 | FunctionCallee MsanPoisonAllocaFn, MsanUnpoisonAllocaFn; | |||
588 | ||||
589 | /// Each of the MsanMetadataPtrXxx functions returns a pair of shadow/origin | |||
590 | /// pointers. | |||
591 | FunctionCallee MsanMetadataPtrForLoadN, MsanMetadataPtrForStoreN; | |||
592 | FunctionCallee MsanMetadataPtrForLoad_1_8[4]; | |||
593 | FunctionCallee MsanMetadataPtrForStore_1_8[4]; | |||
594 | FunctionCallee MsanInstrumentAsmStoreFn; | |||
595 | ||||
596 | /// Helper to choose between different MsanMetadataPtrXxx(). | |||
597 | FunctionCallee getKmsanShadowOriginAccessFn(bool isStore, int size); | |||
598 | ||||
599 | /// Memory map parameters used in application-to-shadow calculation. | |||
600 | const MemoryMapParams *MapParams; | |||
601 | ||||
602 | /// Custom memory map parameters used when -msan-shadow-base or | |||
603 | // -msan-origin-base is provided. | |||
604 | MemoryMapParams CustomMapParams; | |||
605 | ||||
606 | MDNode *ColdCallWeights; | |||
607 | ||||
608 | /// Branch weights for origin store. | |||
609 | MDNode *OriginStoreWeights; | |||
610 | }; | |||
611 | ||||
612 | void insertModuleCtor(Module &M) { | |||
613 | getOrCreateSanitizerCtorAndInitFunctions( | |||
614 | M, kMsanModuleCtorName, kMsanInitName, | |||
615 | /*InitArgTypes=*/{}, | |||
616 | /*InitArgs=*/{}, | |||
617 | // This callback is invoked when the functions are created the first | |||
618 | // time. Hook them into the global ctors list in that case: | |||
619 | [&](Function *Ctor, FunctionCallee) { | |||
620 | if (!ClWithComdat) { | |||
621 | appendToGlobalCtors(M, Ctor, 0); | |||
622 | return; | |||
623 | } | |||
624 | Comdat *MsanCtorComdat = M.getOrInsertComdat(kMsanModuleCtorName); | |||
625 | Ctor->setComdat(MsanCtorComdat); | |||
626 | appendToGlobalCtors(M, Ctor, 0, Ctor); | |||
627 | }); | |||
628 | } | |||
629 | ||||
630 | /// A legacy function pass for msan instrumentation. | |||
631 | /// | |||
632 | /// Instruments functions to detect uninitialized reads. | |||
633 | struct MemorySanitizerLegacyPass : public FunctionPass { | |||
634 | // Pass identification, replacement for typeid. | |||
635 | static char ID; | |||
636 | ||||
637 | MemorySanitizerLegacyPass(MemorySanitizerOptions Options = {}) | |||
638 | : FunctionPass(ID), Options(Options) { | |||
639 | initializeMemorySanitizerLegacyPassPass(*PassRegistry::getPassRegistry()); | |||
640 | } | |||
641 | StringRef getPassName() const override { return "MemorySanitizerLegacyPass"; } | |||
642 | ||||
643 | void getAnalysisUsage(AnalysisUsage &AU) const override { | |||
644 | AU.addRequired<TargetLibraryInfoWrapperPass>(); | |||
645 | } | |||
646 | ||||
647 | bool runOnFunction(Function &F) override { | |||
648 | return MSan->sanitizeFunction( | |||
649 | F, getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F)); | |||
650 | } | |||
651 | bool doInitialization(Module &M) override; | |||
652 | ||||
653 | Optional<MemorySanitizer> MSan; | |||
654 | MemorySanitizerOptions Options; | |||
655 | }; | |||
656 | ||||
657 | template <class T> T getOptOrDefault(const cl::opt<T> &Opt, T Default) { | |||
658 | return (Opt.getNumOccurrences() > 0) ? Opt : Default; | |||
659 | } | |||
660 | ||||
661 | } // end anonymous namespace | |||
662 | ||||
663 | MemorySanitizerOptions::MemorySanitizerOptions(int TO, bool R, bool K) | |||
664 | : Kernel(getOptOrDefault(ClEnableKmsan, K)), | |||
665 | TrackOrigins(getOptOrDefault(ClTrackOrigins, Kernel ? 2 : TO)), | |||
666 | Recover(getOptOrDefault(ClKeepGoing, Kernel || R)) {} | |||
667 | ||||
668 | PreservedAnalyses MemorySanitizerPass::run(Function &F, | |||
669 | FunctionAnalysisManager &FAM) { | |||
670 | MemorySanitizer Msan(*F.getParent(), Options); | |||
671 | if (Msan.sanitizeFunction(F, FAM.getResult<TargetLibraryAnalysis>(F))) | |||
672 | return PreservedAnalyses::none(); | |||
673 | return PreservedAnalyses::all(); | |||
674 | } | |||
675 | ||||
676 | PreservedAnalyses MemorySanitizerPass::run(Module &M, | |||
677 | ModuleAnalysisManager &AM) { | |||
678 | if (Options.Kernel) | |||
679 | return PreservedAnalyses::all(); | |||
680 | insertModuleCtor(M); | |||
681 | return PreservedAnalyses::none(); | |||
682 | } | |||
683 | ||||
684 | char MemorySanitizerLegacyPass::ID = 0; | |||
685 | ||||
686 | INITIALIZE_PASS_BEGIN(MemorySanitizerLegacyPass, "msan",static void *initializeMemorySanitizerLegacyPassPassOnce(PassRegistry &Registry) { | |||
687 | "MemorySanitizer: detects uninitialized reads.", false,static void *initializeMemorySanitizerLegacyPassPassOnce(PassRegistry &Registry) { | |||
688 | false)static void *initializeMemorySanitizerLegacyPassPassOnce(PassRegistry &Registry) { | |||
689 | INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)initializeTargetLibraryInfoWrapperPassPass(Registry); | |||
690 | INITIALIZE_PASS_END(MemorySanitizerLegacyPass, "msan",PassInfo *PI = new PassInfo( "MemorySanitizer: detects uninitialized reads." , "msan", &MemorySanitizerLegacyPass::ID, PassInfo::NormalCtor_t (callDefaultCtor<MemorySanitizerLegacyPass>), false, false ); Registry.registerPass(*PI, true); return PI; } static llvm ::once_flag InitializeMemorySanitizerLegacyPassPassFlag; void llvm::initializeMemorySanitizerLegacyPassPass(PassRegistry & Registry) { llvm::call_once(InitializeMemorySanitizerLegacyPassPassFlag , initializeMemorySanitizerLegacyPassPassOnce, std::ref(Registry )); } | |||
691 | "MemorySanitizer: detects uninitialized reads.", false,PassInfo *PI = new PassInfo( "MemorySanitizer: detects uninitialized reads." , "msan", &MemorySanitizerLegacyPass::ID, PassInfo::NormalCtor_t (callDefaultCtor<MemorySanitizerLegacyPass>), false, false ); Registry.registerPass(*PI, true); return PI; } static llvm ::once_flag InitializeMemorySanitizerLegacyPassPassFlag; void llvm::initializeMemorySanitizerLegacyPassPass(PassRegistry & Registry) { llvm::call_once(InitializeMemorySanitizerLegacyPassPassFlag , initializeMemorySanitizerLegacyPassPassOnce, std::ref(Registry )); } | |||
692 | false)PassInfo *PI = new PassInfo( "MemorySanitizer: detects uninitialized reads." , "msan", &MemorySanitizerLegacyPass::ID, PassInfo::NormalCtor_t (callDefaultCtor<MemorySanitizerLegacyPass>), false, false ); Registry.registerPass(*PI, true); return PI; } static llvm ::once_flag InitializeMemorySanitizerLegacyPassPassFlag; void llvm::initializeMemorySanitizerLegacyPassPass(PassRegistry & Registry) { llvm::call_once(InitializeMemorySanitizerLegacyPassPassFlag , initializeMemorySanitizerLegacyPassPassOnce, std::ref(Registry )); } | |||
693 | ||||
694 | FunctionPass * | |||
695 | llvm::createMemorySanitizerLegacyPassPass(MemorySanitizerOptions Options) { | |||
696 | return new MemorySanitizerLegacyPass(Options); | |||
697 | } | |||
698 | ||||
699 | /// Create a non-const global initialized with the given string. | |||
700 | /// | |||
701 | /// Creates a writable global for Str so that we can pass it to the | |||
702 | /// run-time lib. Runtime uses first 4 bytes of the string to store the | |||
703 | /// frame ID, so the string needs to be mutable. | |||
704 | static GlobalVariable *createPrivateNonConstGlobalForString(Module &M, | |||
705 | StringRef Str) { | |||
706 | Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str); | |||
707 | return new GlobalVariable(M, StrConst->getType(), /*isConstant=*/false, | |||
708 | GlobalValue::PrivateLinkage, StrConst, ""); | |||
709 | } | |||
710 | ||||
711 | /// Create KMSAN API callbacks. | |||
712 | void MemorySanitizer::createKernelApi(Module &M) { | |||
713 | IRBuilder<> IRB(*C); | |||
714 | ||||
715 | // These will be initialized in insertKmsanPrologue(). | |||
716 | RetvalTLS = nullptr; | |||
717 | RetvalOriginTLS = nullptr; | |||
718 | ParamTLS = nullptr; | |||
719 | ParamOriginTLS = nullptr; | |||
720 | VAArgTLS = nullptr; | |||
721 | VAArgOriginTLS = nullptr; | |||
722 | VAArgOverflowSizeTLS = nullptr; | |||
723 | ||||
724 | WarningFn = M.getOrInsertFunction("__msan_warning", IRB.getVoidTy(), | |||
725 | IRB.getInt32Ty()); | |||
726 | // Requests the per-task context state (kmsan_context_state*) from the | |||
727 | // runtime library. | |||
728 | MsanContextStateTy = StructType::get( | |||
729 | ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8), | |||
730 | ArrayType::get(IRB.getInt64Ty(), kRetvalTLSSize / 8), | |||
731 | ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8), | |||
732 | ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8), /* va_arg_origin */ | |||
733 | IRB.getInt64Ty(), ArrayType::get(OriginTy, kParamTLSSize / 4), OriginTy, | |||
734 | OriginTy); | |||
735 | MsanGetContextStateFn = M.getOrInsertFunction( | |||
736 | "__msan_get_context_state", PointerType::get(MsanContextStateTy, 0)); | |||
737 | ||||
738 | Type *RetTy = StructType::get(PointerType::get(IRB.getInt8Ty(), 0), | |||
739 | PointerType::get(IRB.getInt32Ty(), 0)); | |||
740 | ||||
741 | for (int ind = 0, size = 1; ind < 4; ind++, size <<= 1) { | |||
742 | std::string name_load = | |||
743 | "__msan_metadata_ptr_for_load_" + std::to_string(size); | |||
744 | std::string name_store = | |||
745 | "__msan_metadata_ptr_for_store_" + std::to_string(size); | |||
746 | MsanMetadataPtrForLoad_1_8[ind] = M.getOrInsertFunction( | |||
747 | name_load, RetTy, PointerType::get(IRB.getInt8Ty(), 0)); | |||
748 | MsanMetadataPtrForStore_1_8[ind] = M.getOrInsertFunction( | |||
749 | name_store, RetTy, PointerType::get(IRB.getInt8Ty(), 0)); | |||
750 | } | |||
751 | ||||
752 | MsanMetadataPtrForLoadN = M.getOrInsertFunction( | |||
753 | "__msan_metadata_ptr_for_load_n", RetTy, | |||
754 | PointerType::get(IRB.getInt8Ty(), 0), IRB.getInt64Ty()); | |||
755 | MsanMetadataPtrForStoreN = M.getOrInsertFunction( | |||
756 | "__msan_metadata_ptr_for_store_n", RetTy, | |||
757 | PointerType::get(IRB.getInt8Ty(), 0), IRB.getInt64Ty()); | |||
758 | ||||
759 | // Functions for poisoning and unpoisoning memory. | |||
760 | MsanPoisonAllocaFn = | |||
761 | M.getOrInsertFunction("__msan_poison_alloca", IRB.getVoidTy(), | |||
762 | IRB.getInt8PtrTy(), IntptrTy, IRB.getInt8PtrTy()); | |||
763 | MsanUnpoisonAllocaFn = M.getOrInsertFunction( | |||
764 | "__msan_unpoison_alloca", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy); | |||
765 | } | |||
766 | ||||
767 | static Constant *getOrInsertGlobal(Module &M, StringRef Name, Type *Ty) { | |||
768 | return M.getOrInsertGlobal(Name, Ty, [&] { | |||
769 | return new GlobalVariable(M, Ty, false, GlobalVariable::ExternalLinkage, | |||
770 | nullptr, Name, nullptr, | |||
771 | GlobalVariable::InitialExecTLSModel); | |||
772 | }); | |||
773 | } | |||
774 | ||||
775 | /// Insert declarations for userspace-specific functions and globals. | |||
776 | void MemorySanitizer::createUserspaceApi(Module &M) { | |||
777 | IRBuilder<> IRB(*C); | |||
778 | ||||
779 | // Create the callback. | |||
780 | // FIXME: this function should have "Cold" calling conv, | |||
781 | // which is not yet implemented. | |||
782 | StringRef WarningFnName = Recover ? "__msan_warning_with_origin" | |||
783 | : "__msan_warning_with_origin_noreturn"; | |||
784 | WarningFn = | |||
785 | M.getOrInsertFunction(WarningFnName, IRB.getVoidTy(), IRB.getInt32Ty()); | |||
786 | ||||
787 | // Create the global TLS variables. | |||
788 | RetvalTLS = | |||
789 | getOrInsertGlobal(M, "__msan_retval_tls", | |||
790 | ArrayType::get(IRB.getInt64Ty(), kRetvalTLSSize / 8)); | |||
791 | ||||
792 | RetvalOriginTLS = getOrInsertGlobal(M, "__msan_retval_origin_tls", OriginTy); | |||
793 | ||||
794 | ParamTLS = | |||
795 | getOrInsertGlobal(M, "__msan_param_tls", | |||
796 | ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8)); | |||
797 | ||||
798 | ParamOriginTLS = | |||
799 | getOrInsertGlobal(M, "__msan_param_origin_tls", | |||
800 | ArrayType::get(OriginTy, kParamTLSSize / 4)); | |||
801 | ||||
802 | VAArgTLS = | |||
803 | getOrInsertGlobal(M, "__msan_va_arg_tls", | |||
804 | ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8)); | |||
805 | ||||
806 | VAArgOriginTLS = | |||
807 | getOrInsertGlobal(M, "__msan_va_arg_origin_tls", | |||
808 | ArrayType::get(OriginTy, kParamTLSSize / 4)); | |||
809 | ||||
810 | VAArgOverflowSizeTLS = | |||
811 | getOrInsertGlobal(M, "__msan_va_arg_overflow_size_tls", IRB.getInt64Ty()); | |||
812 | ||||
813 | for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes; | |||
814 | AccessSizeIndex++) { | |||
815 | unsigned AccessSize = 1 << AccessSizeIndex; | |||
816 | std::string FunctionName = "__msan_maybe_warning_" + itostr(AccessSize); | |||
817 | SmallVector<std::pair<unsigned, Attribute>, 2> MaybeWarningFnAttrs; | |||
818 | MaybeWarningFnAttrs.push_back(std::make_pair( | |||
819 | AttributeList::FirstArgIndex, Attribute::get(*C, Attribute::ZExt))); | |||
820 | MaybeWarningFnAttrs.push_back(std::make_pair( | |||
821 | AttributeList::FirstArgIndex + 1, Attribute::get(*C, Attribute::ZExt))); | |||
822 | MaybeWarningFn[AccessSizeIndex] = M.getOrInsertFunction( | |||
823 | FunctionName, AttributeList::get(*C, MaybeWarningFnAttrs), | |||
824 | IRB.getVoidTy(), IRB.getIntNTy(AccessSize * 8), IRB.getInt32Ty()); | |||
825 | ||||
826 | FunctionName = "__msan_maybe_store_origin_" + itostr(AccessSize); | |||
827 | SmallVector<std::pair<unsigned, Attribute>, 2> MaybeStoreOriginFnAttrs; | |||
828 | MaybeStoreOriginFnAttrs.push_back(std::make_pair( | |||
829 | AttributeList::FirstArgIndex, Attribute::get(*C, Attribute::ZExt))); | |||
830 | MaybeStoreOriginFnAttrs.push_back(std::make_pair( | |||
831 | AttributeList::FirstArgIndex + 2, Attribute::get(*C, Attribute::ZExt))); | |||
832 | MaybeStoreOriginFn[AccessSizeIndex] = M.getOrInsertFunction( | |||
833 | FunctionName, AttributeList::get(*C, MaybeStoreOriginFnAttrs), | |||
834 | IRB.getVoidTy(), IRB.getIntNTy(AccessSize * 8), IRB.getInt8PtrTy(), | |||
835 | IRB.getInt32Ty()); | |||
836 | } | |||
837 | ||||
838 | MsanSetAllocaOrigin4Fn = M.getOrInsertFunction( | |||
839 | "__msan_set_alloca_origin4", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy, | |||
840 | IRB.getInt8PtrTy(), IntptrTy); | |||
841 | MsanPoisonStackFn = | |||
842 | M.getOrInsertFunction("__msan_poison_stack", IRB.getVoidTy(), | |||
843 | IRB.getInt8PtrTy(), IntptrTy); | |||
844 | } | |||
845 | ||||
846 | /// Insert extern declaration of runtime-provided functions and globals. | |||
847 | void MemorySanitizer::initializeCallbacks(Module &M) { | |||
848 | // Only do this once. | |||
849 | if (CallbacksInitialized) | |||
850 | return; | |||
851 | ||||
852 | IRBuilder<> IRB(*C); | |||
853 | // Initialize callbacks that are common for kernel and userspace | |||
854 | // instrumentation. | |||
855 | MsanChainOriginFn = M.getOrInsertFunction( | |||
856 | "__msan_chain_origin", IRB.getInt32Ty(), IRB.getInt32Ty()); | |||
857 | MsanSetOriginFn = | |||
858 | M.getOrInsertFunction("__msan_set_origin", IRB.getVoidTy(), | |||
859 | IRB.getInt8PtrTy(), IntptrTy, IRB.getInt32Ty()); | |||
860 | MemmoveFn = M.getOrInsertFunction( | |||
861 | "__msan_memmove", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), | |||
862 | IRB.getInt8PtrTy(), IntptrTy); | |||
863 | MemcpyFn = M.getOrInsertFunction( | |||
864 | "__msan_memcpy", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), | |||
865 | IntptrTy); | |||
866 | MemsetFn = M.getOrInsertFunction( | |||
867 | "__msan_memset", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IRB.getInt32Ty(), | |||
868 | IntptrTy); | |||
869 | ||||
870 | MsanInstrumentAsmStoreFn = | |||
871 | M.getOrInsertFunction("__msan_instrument_asm_store", IRB.getVoidTy(), | |||
872 | PointerType::get(IRB.getInt8Ty(), 0), IntptrTy); | |||
873 | ||||
874 | if (CompileKernel) { | |||
875 | createKernelApi(M); | |||
876 | } else { | |||
877 | createUserspaceApi(M); | |||
878 | } | |||
879 | CallbacksInitialized = true; | |||
880 | } | |||
881 | ||||
882 | FunctionCallee MemorySanitizer::getKmsanShadowOriginAccessFn(bool isStore, | |||
883 | int size) { | |||
884 | FunctionCallee *Fns = | |||
885 | isStore ? MsanMetadataPtrForStore_1_8 : MsanMetadataPtrForLoad_1_8; | |||
886 | switch (size) { | |||
887 | case 1: | |||
888 | return Fns[0]; | |||
889 | case 2: | |||
890 | return Fns[1]; | |||
891 | case 4: | |||
892 | return Fns[2]; | |||
893 | case 8: | |||
894 | return Fns[3]; | |||
895 | default: | |||
896 | return nullptr; | |||
897 | } | |||
898 | } | |||
899 | ||||
900 | /// Module-level initialization. | |||
901 | /// | |||
902 | /// inserts a call to __msan_init to the module's constructor list. | |||
903 | void MemorySanitizer::initializeModule(Module &M) { | |||
904 | auto &DL = M.getDataLayout(); | |||
905 | ||||
906 | bool ShadowPassed = ClShadowBase.getNumOccurrences() > 0; | |||
907 | bool OriginPassed = ClOriginBase.getNumOccurrences() > 0; | |||
908 | // Check the overrides first | |||
909 | if (ShadowPassed || OriginPassed) { | |||
910 | CustomMapParams.AndMask = ClAndMask; | |||
911 | CustomMapParams.XorMask = ClXorMask; | |||
912 | CustomMapParams.ShadowBase = ClShadowBase; | |||
913 | CustomMapParams.OriginBase = ClOriginBase; | |||
914 | MapParams = &CustomMapParams; | |||
915 | } else { | |||
916 | Triple TargetTriple(M.getTargetTriple()); | |||
917 | switch (TargetTriple.getOS()) { | |||
918 | case Triple::FreeBSD: | |||
919 | switch (TargetTriple.getArch()) { | |||
920 | case Triple::x86_64: | |||
921 | MapParams = FreeBSD_X86_MemoryMapParams.bits64; | |||
922 | break; | |||
923 | case Triple::x86: | |||
924 | MapParams = FreeBSD_X86_MemoryMapParams.bits32; | |||
925 | break; | |||
926 | default: | |||
927 | report_fatal_error("unsupported architecture"); | |||
928 | } | |||
929 | break; | |||
930 | case Triple::NetBSD: | |||
931 | switch (TargetTriple.getArch()) { | |||
932 | case Triple::x86_64: | |||
933 | MapParams = NetBSD_X86_MemoryMapParams.bits64; | |||
934 | break; | |||
935 | default: | |||
936 | report_fatal_error("unsupported architecture"); | |||
937 | } | |||
938 | break; | |||
939 | case Triple::Linux: | |||
940 | switch (TargetTriple.getArch()) { | |||
941 | case Triple::x86_64: | |||
942 | MapParams = Linux_X86_MemoryMapParams.bits64; | |||
943 | break; | |||
944 | case Triple::x86: | |||
945 | MapParams = Linux_X86_MemoryMapParams.bits32; | |||
946 | break; | |||
947 | case Triple::mips64: | |||
948 | case Triple::mips64el: | |||
949 | MapParams = Linux_MIPS_MemoryMapParams.bits64; | |||
950 | break; | |||
951 | case Triple::ppc64: | |||
952 | case Triple::ppc64le: | |||
953 | MapParams = Linux_PowerPC_MemoryMapParams.bits64; | |||
954 | break; | |||
955 | case Triple::systemz: | |||
956 | MapParams = Linux_S390_MemoryMapParams.bits64; | |||
957 | break; | |||
958 | case Triple::aarch64: | |||
959 | case Triple::aarch64_be: | |||
960 | MapParams = Linux_ARM_MemoryMapParams.bits64; | |||
961 | break; | |||
962 | default: | |||
963 | report_fatal_error("unsupported architecture"); | |||
964 | } | |||
965 | break; | |||
966 | default: | |||
967 | report_fatal_error("unsupported operating system"); | |||
968 | } | |||
969 | } | |||
970 | ||||
971 | C = &(M.getContext()); | |||
972 | IRBuilder<> IRB(*C); | |||
973 | IntptrTy = IRB.getIntPtrTy(DL); | |||
974 | OriginTy = IRB.getInt32Ty(); | |||
975 | ||||
976 | ColdCallWeights = MDBuilder(*C).createBranchWeights(1, 1000); | |||
977 | OriginStoreWeights = MDBuilder(*C).createBranchWeights(1, 1000); | |||
978 | ||||
979 | if (!CompileKernel) { | |||
980 | if (TrackOrigins) | |||
981 | M.getOrInsertGlobal("__msan_track_origins", IRB.getInt32Ty(), [&] { | |||
982 | return new GlobalVariable( | |||
983 | M, IRB.getInt32Ty(), true, GlobalValue::WeakODRLinkage, | |||
984 | IRB.getInt32(TrackOrigins), "__msan_track_origins"); | |||
985 | }); | |||
986 | ||||
987 | if (Recover) | |||
988 | M.getOrInsertGlobal("__msan_keep_going", IRB.getInt32Ty(), [&] { | |||
989 | return new GlobalVariable(M, IRB.getInt32Ty(), true, | |||
990 | GlobalValue::WeakODRLinkage, | |||
991 | IRB.getInt32(Recover), "__msan_keep_going"); | |||
992 | }); | |||
993 | } | |||
994 | } | |||
995 | ||||
996 | bool MemorySanitizerLegacyPass::doInitialization(Module &M) { | |||
997 | if (!Options.Kernel) | |||
998 | insertModuleCtor(M); | |||
999 | MSan.emplace(M, Options); | |||
1000 | return true; | |||
1001 | } | |||
1002 | ||||
1003 | namespace { | |||
1004 | ||||
1005 | /// A helper class that handles instrumentation of VarArg | |||
1006 | /// functions on a particular platform. | |||
1007 | /// | |||
1008 | /// Implementations are expected to insert the instrumentation | |||
1009 | /// necessary to propagate argument shadow through VarArg function | |||
1010 | /// calls. Visit* methods are called during an InstVisitor pass over | |||
1011 | /// the function, and should avoid creating new basic blocks. A new | |||
1012 | /// instance of this class is created for each instrumented function. | |||
1013 | struct VarArgHelper { | |||
1014 | virtual ~VarArgHelper() = default; | |||
1015 | ||||
1016 | /// Visit a CallBase. | |||
1017 | virtual void visitCallBase(CallBase &CB, IRBuilder<> &IRB) = 0; | |||
1018 | ||||
1019 | /// Visit a va_start call. | |||
1020 | virtual void visitVAStartInst(VAStartInst &I) = 0; | |||
1021 | ||||
1022 | /// Visit a va_copy call. | |||
1023 | virtual void visitVACopyInst(VACopyInst &I) = 0; | |||
1024 | ||||
1025 | /// Finalize function instrumentation. | |||
1026 | /// | |||
1027 | /// This method is called after visiting all interesting (see above) | |||
1028 | /// instructions in a function. | |||
1029 | virtual void finalizeInstrumentation() = 0; | |||
1030 | }; | |||
1031 | ||||
1032 | struct MemorySanitizerVisitor; | |||
1033 | ||||
1034 | } // end anonymous namespace | |||
1035 | ||||
1036 | static VarArgHelper *CreateVarArgHelper(Function &Func, MemorySanitizer &Msan, | |||
1037 | MemorySanitizerVisitor &Visitor); | |||
1038 | ||||
1039 | static unsigned TypeSizeToSizeIndex(unsigned TypeSize) { | |||
1040 | if (TypeSize <= 8) return 0; | |||
1041 | return Log2_32_Ceil((TypeSize + 7) / 8); | |||
1042 | } | |||
1043 | ||||
1044 | namespace { | |||
1045 | ||||
1046 | /// This class does all the work for a given function. Store and Load | |||
1047 | /// instructions store and load corresponding shadow and origin | |||
1048 | /// values. Most instructions propagate shadow from arguments to their | |||
1049 | /// return values. Certain instructions (most importantly, BranchInst) | |||
1050 | /// test their argument shadow and print reports (with a runtime call) if it's | |||
1051 | /// non-zero. | |||
1052 | struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> { | |||
1053 | Function &F; | |||
1054 | MemorySanitizer &MS; | |||
1055 | SmallVector<PHINode *, 16> ShadowPHINodes, OriginPHINodes; | |||
1056 | ValueMap<Value*, Value*> ShadowMap, OriginMap; | |||
1057 | std::unique_ptr<VarArgHelper> VAHelper; | |||
1058 | const TargetLibraryInfo *TLI; | |||
1059 | Instruction *FnPrologueEnd; | |||
1060 | ||||
1061 | // The following flags disable parts of MSan instrumentation based on | |||
1062 | // exclusion list contents and command-line options. | |||
1063 | bool InsertChecks; | |||
1064 | bool PropagateShadow; | |||
1065 | bool PoisonStack; | |||
1066 | bool PoisonUndef; | |||
1067 | ||||
1068 | struct ShadowOriginAndInsertPoint { | |||
1069 | Value *Shadow; | |||
1070 | Value *Origin; | |||
1071 | Instruction *OrigIns; | |||
1072 | ||||
1073 | ShadowOriginAndInsertPoint(Value *S, Value *O, Instruction *I) | |||
1074 | : Shadow(S), Origin(O), OrigIns(I) {} | |||
1075 | }; | |||
1076 | SmallVector<ShadowOriginAndInsertPoint, 16> InstrumentationList; | |||
1077 | bool InstrumentLifetimeStart = ClHandleLifetimeIntrinsics; | |||
1078 | SmallSet<AllocaInst *, 16> AllocaSet; | |||
1079 | SmallVector<std::pair<IntrinsicInst *, AllocaInst *>, 16> LifetimeStartList; | |||
1080 | SmallVector<StoreInst *, 16> StoreList; | |||
1081 | ||||
1082 | MemorySanitizerVisitor(Function &F, MemorySanitizer &MS, | |||
1083 | const TargetLibraryInfo &TLI) | |||
1084 | : F(F), MS(MS), VAHelper(CreateVarArgHelper(F, MS, *this)), TLI(&TLI) { | |||
1085 | bool SanitizeFunction = F.hasFnAttribute(Attribute::SanitizeMemory); | |||
1086 | InsertChecks = SanitizeFunction; | |||
1087 | PropagateShadow = SanitizeFunction; | |||
1088 | PoisonStack = SanitizeFunction && ClPoisonStack; | |||
1089 | PoisonUndef = SanitizeFunction && ClPoisonUndef; | |||
1090 | ||||
1091 | // In the presence of unreachable blocks, we may see Phi nodes with | |||
1092 | // incoming nodes from such blocks. Since InstVisitor skips unreachable | |||
1093 | // blocks, such nodes will not have any shadow value associated with them. | |||
1094 | // It's easier to remove unreachable blocks than deal with missing shadow. | |||
1095 | removeUnreachableBlocks(F); | |||
1096 | ||||
1097 | MS.initializeCallbacks(*F.getParent()); | |||
1098 | FnPrologueEnd = IRBuilder<>(F.getEntryBlock().getFirstNonPHI()) | |||
1099 | .CreateIntrinsic(Intrinsic::donothing, {}, {}); | |||
1100 | ||||
1101 | if (MS.CompileKernel) { | |||
1102 | IRBuilder<> IRB(FnPrologueEnd); | |||
1103 | insertKmsanPrologue(IRB); | |||
1104 | } | |||
1105 | ||||
1106 | LLVM_DEBUG(if (!InsertChecks) dbgs()do { } while (false) | |||
1107 | << "MemorySanitizer is not inserting checks into '"do { } while (false) | |||
1108 | << F.getName() << "'\n")do { } while (false); | |||
1109 | } | |||
1110 | ||||
1111 | bool isInPrologue(Instruction &I) { | |||
1112 | return I.getParent() == FnPrologueEnd->getParent() && | |||
1113 | (&I == FnPrologueEnd || I.comesBefore(FnPrologueEnd)); | |||
1114 | } | |||
1115 | ||||
1116 | Value *updateOrigin(Value *V, IRBuilder<> &IRB) { | |||
1117 | if (MS.TrackOrigins <= 1) return V; | |||
1118 | return IRB.CreateCall(MS.MsanChainOriginFn, V); | |||
1119 | } | |||
1120 | ||||
1121 | Value *originToIntptr(IRBuilder<> &IRB, Value *Origin) { | |||
1122 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
1123 | unsigned IntptrSize = DL.getTypeStoreSize(MS.IntptrTy); | |||
1124 | if (IntptrSize == kOriginSize) return Origin; | |||
1125 | assert(IntptrSize == kOriginSize * 2)((void)0); | |||
1126 | Origin = IRB.CreateIntCast(Origin, MS.IntptrTy, /* isSigned */ false); | |||
1127 | return IRB.CreateOr(Origin, IRB.CreateShl(Origin, kOriginSize * 8)); | |||
1128 | } | |||
1129 | ||||
1130 | /// Fill memory range with the given origin value. | |||
1131 | void paintOrigin(IRBuilder<> &IRB, Value *Origin, Value *OriginPtr, | |||
1132 | unsigned Size, Align Alignment) { | |||
1133 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
1134 | const Align IntptrAlignment = DL.getABITypeAlign(MS.IntptrTy); | |||
1135 | unsigned IntptrSize = DL.getTypeStoreSize(MS.IntptrTy); | |||
1136 | assert(IntptrAlignment >= kMinOriginAlignment)((void)0); | |||
1137 | assert(IntptrSize >= kOriginSize)((void)0); | |||
1138 | ||||
1139 | unsigned Ofs = 0; | |||
1140 | Align CurrentAlignment = Alignment; | |||
1141 | if (Alignment >= IntptrAlignment && IntptrSize > kOriginSize) { | |||
1142 | Value *IntptrOrigin = originToIntptr(IRB, Origin); | |||
1143 | Value *IntptrOriginPtr = | |||
1144 | IRB.CreatePointerCast(OriginPtr, PointerType::get(MS.IntptrTy, 0)); | |||
1145 | for (unsigned i = 0; i < Size / IntptrSize; ++i) { | |||
1146 | Value *Ptr = i ? IRB.CreateConstGEP1_32(MS.IntptrTy, IntptrOriginPtr, i) | |||
1147 | : IntptrOriginPtr; | |||
1148 | IRB.CreateAlignedStore(IntptrOrigin, Ptr, CurrentAlignment); | |||
1149 | Ofs += IntptrSize / kOriginSize; | |||
1150 | CurrentAlignment = IntptrAlignment; | |||
1151 | } | |||
1152 | } | |||
1153 | ||||
1154 | for (unsigned i = Ofs; i < (Size + kOriginSize - 1) / kOriginSize; ++i) { | |||
1155 | Value *GEP = | |||
1156 | i ? IRB.CreateConstGEP1_32(MS.OriginTy, OriginPtr, i) : OriginPtr; | |||
1157 | IRB.CreateAlignedStore(Origin, GEP, CurrentAlignment); | |||
1158 | CurrentAlignment = kMinOriginAlignment; | |||
1159 | } | |||
1160 | } | |||
1161 | ||||
1162 | void storeOrigin(IRBuilder<> &IRB, Value *Addr, Value *Shadow, Value *Origin, | |||
1163 | Value *OriginPtr, Align Alignment, bool AsCall) { | |||
1164 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
1165 | const Align OriginAlignment = std::max(kMinOriginAlignment, Alignment); | |||
1166 | unsigned StoreSize = DL.getTypeStoreSize(Shadow->getType()); | |||
1167 | Value *ConvertedShadow = convertShadowToScalar(Shadow, IRB); | |||
1168 | if (auto *ConstantShadow = dyn_cast<Constant>(ConvertedShadow)) { | |||
1169 | if (ClCheckConstantShadow && !ConstantShadow->isZeroValue()) | |||
1170 | paintOrigin(IRB, updateOrigin(Origin, IRB), OriginPtr, StoreSize, | |||
1171 | OriginAlignment); | |||
1172 | return; | |||
1173 | } | |||
1174 | ||||
1175 | unsigned TypeSizeInBits = DL.getTypeSizeInBits(ConvertedShadow->getType()); | |||
1176 | unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits); | |||
1177 | if (AsCall && SizeIndex < kNumberOfAccessSizes && !MS.CompileKernel) { | |||
1178 | FunctionCallee Fn = MS.MaybeStoreOriginFn[SizeIndex]; | |||
1179 | Value *ConvertedShadow2 = | |||
1180 | IRB.CreateZExt(ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex))); | |||
1181 | CallBase *CB = IRB.CreateCall( | |||
1182 | Fn, {ConvertedShadow2, | |||
1183 | IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()), Origin}); | |||
1184 | CB->addParamAttr(0, Attribute::ZExt); | |||
1185 | CB->addParamAttr(2, Attribute::ZExt); | |||
1186 | } else { | |||
1187 | Value *Cmp = convertToBool(ConvertedShadow, IRB, "_mscmp"); | |||
1188 | Instruction *CheckTerm = SplitBlockAndInsertIfThen( | |||
1189 | Cmp, &*IRB.GetInsertPoint(), false, MS.OriginStoreWeights); | |||
1190 | IRBuilder<> IRBNew(CheckTerm); | |||
1191 | paintOrigin(IRBNew, updateOrigin(Origin, IRBNew), OriginPtr, StoreSize, | |||
1192 | OriginAlignment); | |||
1193 | } | |||
1194 | } | |||
1195 | ||||
1196 | void materializeStores(bool InstrumentWithCalls) { | |||
1197 | for (StoreInst *SI : StoreList) { | |||
1198 | IRBuilder<> IRB(SI); | |||
1199 | Value *Val = SI->getValueOperand(); | |||
1200 | Value *Addr = SI->getPointerOperand(); | |||
1201 | Value *Shadow = SI->isAtomic() ? getCleanShadow(Val) : getShadow(Val); | |||
1202 | Value *ShadowPtr, *OriginPtr; | |||
1203 | Type *ShadowTy = Shadow->getType(); | |||
1204 | const Align Alignment = assumeAligned(SI->getAlignment()); | |||
1205 | const Align OriginAlignment = std::max(kMinOriginAlignment, Alignment); | |||
1206 | std::tie(ShadowPtr, OriginPtr) = | |||
1207 | getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ true); | |||
1208 | ||||
1209 | StoreInst *NewSI = IRB.CreateAlignedStore(Shadow, ShadowPtr, Alignment); | |||
1210 | LLVM_DEBUG(dbgs() << " STORE: " << *NewSI << "\n")do { } while (false); | |||
1211 | (void)NewSI; | |||
1212 | ||||
1213 | if (SI->isAtomic()) | |||
1214 | SI->setOrdering(addReleaseOrdering(SI->getOrdering())); | |||
1215 | ||||
1216 | if (MS.TrackOrigins && !SI->isAtomic()) | |||
1217 | storeOrigin(IRB, Addr, Shadow, getOrigin(Val), OriginPtr, | |||
1218 | OriginAlignment, InstrumentWithCalls); | |||
1219 | } | |||
1220 | } | |||
1221 | ||||
1222 | /// Helper function to insert a warning at IRB's current insert point. | |||
1223 | void insertWarningFn(IRBuilder<> &IRB, Value *Origin) { | |||
1224 | if (!Origin) | |||
1225 | Origin = (Value *)IRB.getInt32(0); | |||
1226 | assert(Origin->getType()->isIntegerTy())((void)0); | |||
1227 | IRB.CreateCall(MS.WarningFn, Origin)->setCannotMerge(); | |||
1228 | // FIXME: Insert UnreachableInst if !MS.Recover? | |||
1229 | // This may invalidate some of the following checks and needs to be done | |||
1230 | // at the very end. | |||
1231 | } | |||
1232 | ||||
1233 | void materializeOneCheck(Instruction *OrigIns, Value *Shadow, Value *Origin, | |||
1234 | bool AsCall) { | |||
1235 | IRBuilder<> IRB(OrigIns); | |||
1236 | LLVM_DEBUG(dbgs() << " SHAD0 : " << *Shadow << "\n")do { } while (false); | |||
1237 | Value *ConvertedShadow = convertShadowToScalar(Shadow, IRB); | |||
1238 | LLVM_DEBUG(dbgs() << " SHAD1 : " << *ConvertedShadow << "\n")do { } while (false); | |||
1239 | ||||
1240 | if (auto *ConstantShadow = dyn_cast<Constant>(ConvertedShadow)) { | |||
1241 | if (ClCheckConstantShadow && !ConstantShadow->isZeroValue()) { | |||
1242 | insertWarningFn(IRB, Origin); | |||
1243 | } | |||
1244 | return; | |||
1245 | } | |||
1246 | ||||
1247 | const DataLayout &DL = OrigIns->getModule()->getDataLayout(); | |||
1248 | ||||
1249 | unsigned TypeSizeInBits = DL.getTypeSizeInBits(ConvertedShadow->getType()); | |||
1250 | unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits); | |||
1251 | if (AsCall && SizeIndex < kNumberOfAccessSizes && !MS.CompileKernel) { | |||
1252 | FunctionCallee Fn = MS.MaybeWarningFn[SizeIndex]; | |||
1253 | Value *ConvertedShadow2 = | |||
1254 | IRB.CreateZExt(ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex))); | |||
1255 | CallBase *CB = IRB.CreateCall( | |||
1256 | Fn, {ConvertedShadow2, | |||
1257 | MS.TrackOrigins && Origin ? Origin : (Value *)IRB.getInt32(0)}); | |||
1258 | CB->addParamAttr(0, Attribute::ZExt); | |||
1259 | CB->addParamAttr(1, Attribute::ZExt); | |||
1260 | } else { | |||
1261 | Value *Cmp = convertToBool(ConvertedShadow, IRB, "_mscmp"); | |||
1262 | Instruction *CheckTerm = SplitBlockAndInsertIfThen( | |||
1263 | Cmp, OrigIns, | |||
1264 | /* Unreachable */ !MS.Recover, MS.ColdCallWeights); | |||
1265 | ||||
1266 | IRB.SetInsertPoint(CheckTerm); | |||
1267 | insertWarningFn(IRB, Origin); | |||
1268 | LLVM_DEBUG(dbgs() << " CHECK: " << *Cmp << "\n")do { } while (false); | |||
1269 | } | |||
1270 | } | |||
1271 | ||||
1272 | void materializeChecks(bool InstrumentWithCalls) { | |||
1273 | for (const auto &ShadowData : InstrumentationList) { | |||
1274 | Instruction *OrigIns = ShadowData.OrigIns; | |||
1275 | Value *Shadow = ShadowData.Shadow; | |||
1276 | Value *Origin = ShadowData.Origin; | |||
1277 | materializeOneCheck(OrigIns, Shadow, Origin, InstrumentWithCalls); | |||
1278 | } | |||
1279 | LLVM_DEBUG(dbgs() << "DONE:\n" << F)do { } while (false); | |||
1280 | } | |||
1281 | ||||
1282 | // Returns the last instruction in the new prologue | |||
1283 | void insertKmsanPrologue(IRBuilder<> &IRB) { | |||
1284 | Value *ContextState = IRB.CreateCall(MS.MsanGetContextStateFn, {}); | |||
1285 | Constant *Zero = IRB.getInt32(0); | |||
1286 | MS.ParamTLS = IRB.CreateGEP(MS.MsanContextStateTy, ContextState, | |||
1287 | {Zero, IRB.getInt32(0)}, "param_shadow"); | |||
1288 | MS.RetvalTLS = IRB.CreateGEP(MS.MsanContextStateTy, ContextState, | |||
1289 | {Zero, IRB.getInt32(1)}, "retval_shadow"); | |||
1290 | MS.VAArgTLS = IRB.CreateGEP(MS.MsanContextStateTy, ContextState, | |||
1291 | {Zero, IRB.getInt32(2)}, "va_arg_shadow"); | |||
1292 | MS.VAArgOriginTLS = IRB.CreateGEP(MS.MsanContextStateTy, ContextState, | |||
1293 | {Zero, IRB.getInt32(3)}, "va_arg_origin"); | |||
1294 | MS.VAArgOverflowSizeTLS = | |||
1295 | IRB.CreateGEP(MS.MsanContextStateTy, ContextState, | |||
1296 | {Zero, IRB.getInt32(4)}, "va_arg_overflow_size"); | |||
1297 | MS.ParamOriginTLS = IRB.CreateGEP(MS.MsanContextStateTy, ContextState, | |||
1298 | {Zero, IRB.getInt32(5)}, "param_origin"); | |||
1299 | MS.RetvalOriginTLS = | |||
1300 | IRB.CreateGEP(MS.MsanContextStateTy, ContextState, | |||
1301 | {Zero, IRB.getInt32(6)}, "retval_origin"); | |||
1302 | } | |||
1303 | ||||
1304 | /// Add MemorySanitizer instrumentation to a function. | |||
1305 | bool runOnFunction() { | |||
1306 | // Iterate all BBs in depth-first order and create shadow instructions | |||
1307 | // for all instructions (where applicable). | |||
1308 | // For PHI nodes we create dummy shadow PHIs which will be finalized later. | |||
1309 | for (BasicBlock *BB : depth_first(FnPrologueEnd->getParent())) | |||
1310 | visit(*BB); | |||
1311 | ||||
1312 | // Finalize PHI nodes. | |||
1313 | for (PHINode *PN : ShadowPHINodes) { | |||
1314 | PHINode *PNS = cast<PHINode>(getShadow(PN)); | |||
1315 | PHINode *PNO = MS.TrackOrigins ? cast<PHINode>(getOrigin(PN)) : nullptr; | |||
1316 | size_t NumValues = PN->getNumIncomingValues(); | |||
1317 | for (size_t v = 0; v < NumValues; v++) { | |||
1318 | PNS->addIncoming(getShadow(PN, v), PN->getIncomingBlock(v)); | |||
1319 | if (PNO) PNO->addIncoming(getOrigin(PN, v), PN->getIncomingBlock(v)); | |||
1320 | } | |||
1321 | } | |||
1322 | ||||
1323 | VAHelper->finalizeInstrumentation(); | |||
1324 | ||||
1325 | // Poison llvm.lifetime.start intrinsics, if we haven't fallen back to | |||
1326 | // instrumenting only allocas. | |||
1327 | if (InstrumentLifetimeStart) { | |||
1328 | for (auto Item : LifetimeStartList) { | |||
1329 | instrumentAlloca(*Item.second, Item.first); | |||
1330 | AllocaSet.erase(Item.second); | |||
1331 | } | |||
1332 | } | |||
1333 | // Poison the allocas for which we didn't instrument the corresponding | |||
1334 | // lifetime intrinsics. | |||
1335 | for (AllocaInst *AI : AllocaSet) | |||
1336 | instrumentAlloca(*AI); | |||
1337 | ||||
1338 | bool InstrumentWithCalls = ClInstrumentationWithCallThreshold >= 0 && | |||
1339 | InstrumentationList.size() + StoreList.size() > | |||
1340 | (unsigned)ClInstrumentationWithCallThreshold; | |||
1341 | ||||
1342 | // Insert shadow value checks. | |||
1343 | materializeChecks(InstrumentWithCalls); | |||
1344 | ||||
1345 | // Delayed instrumentation of StoreInst. | |||
1346 | // This may not add new address checks. | |||
1347 | materializeStores(InstrumentWithCalls); | |||
1348 | ||||
1349 | return true; | |||
1350 | } | |||
1351 | ||||
1352 | /// Compute the shadow type that corresponds to a given Value. | |||
1353 | Type *getShadowTy(Value *V) { | |||
1354 | return getShadowTy(V->getType()); | |||
1355 | } | |||
1356 | ||||
1357 | /// Compute the shadow type that corresponds to a given Type. | |||
1358 | Type *getShadowTy(Type *OrigTy) { | |||
1359 | if (!OrigTy->isSized()) { | |||
1360 | return nullptr; | |||
1361 | } | |||
1362 | // For integer type, shadow is the same as the original type. | |||
1363 | // This may return weird-sized types like i1. | |||
1364 | if (IntegerType *IT = dyn_cast<IntegerType>(OrigTy)) | |||
1365 | return IT; | |||
1366 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
1367 | if (VectorType *VT = dyn_cast<VectorType>(OrigTy)) { | |||
1368 | uint32_t EltSize = DL.getTypeSizeInBits(VT->getElementType()); | |||
1369 | return FixedVectorType::get(IntegerType::get(*MS.C, EltSize), | |||
1370 | cast<FixedVectorType>(VT)->getNumElements()); | |||
1371 | } | |||
1372 | if (ArrayType *AT = dyn_cast<ArrayType>(OrigTy)) { | |||
1373 | return ArrayType::get(getShadowTy(AT->getElementType()), | |||
1374 | AT->getNumElements()); | |||
1375 | } | |||
1376 | if (StructType *ST = dyn_cast<StructType>(OrigTy)) { | |||
1377 | SmallVector<Type*, 4> Elements; | |||
1378 | for (unsigned i = 0, n = ST->getNumElements(); i < n; i++) | |||
1379 | Elements.push_back(getShadowTy(ST->getElementType(i))); | |||
1380 | StructType *Res = StructType::get(*MS.C, Elements, ST->isPacked()); | |||
1381 | LLVM_DEBUG(dbgs() << "getShadowTy: " << *ST << " ===> " << *Res << "\n")do { } while (false); | |||
1382 | return Res; | |||
1383 | } | |||
1384 | uint32_t TypeSize = DL.getTypeSizeInBits(OrigTy); | |||
1385 | return IntegerType::get(*MS.C, TypeSize); | |||
1386 | } | |||
1387 | ||||
1388 | /// Flatten a vector type. | |||
1389 | Type *getShadowTyNoVec(Type *ty) { | |||
1390 | if (VectorType *vt = dyn_cast<VectorType>(ty)) | |||
1391 | return IntegerType::get(*MS.C, | |||
1392 | vt->getPrimitiveSizeInBits().getFixedSize()); | |||
1393 | return ty; | |||
1394 | } | |||
1395 | ||||
1396 | /// Extract combined shadow of struct elements as a bool | |||
1397 | Value *collapseStructShadow(StructType *Struct, Value *Shadow, | |||
1398 | IRBuilder<> &IRB) { | |||
1399 | Value *FalseVal = IRB.getIntN(/* width */ 1, /* value */ 0); | |||
1400 | Value *Aggregator = FalseVal; | |||
1401 | ||||
1402 | for (unsigned Idx = 0; Idx < Struct->getNumElements(); Idx++) { | |||
1403 | // Combine by ORing together each element's bool shadow | |||
1404 | Value *ShadowItem = IRB.CreateExtractValue(Shadow, Idx); | |||
1405 | Value *ShadowInner = convertShadowToScalar(ShadowItem, IRB); | |||
1406 | Value *ShadowBool = convertToBool(ShadowInner, IRB); | |||
1407 | ||||
1408 | if (Aggregator != FalseVal) | |||
1409 | Aggregator = IRB.CreateOr(Aggregator, ShadowBool); | |||
1410 | else | |||
1411 | Aggregator = ShadowBool; | |||
1412 | } | |||
1413 | ||||
1414 | return Aggregator; | |||
1415 | } | |||
1416 | ||||
1417 | // Extract combined shadow of array elements | |||
1418 | Value *collapseArrayShadow(ArrayType *Array, Value *Shadow, | |||
1419 | IRBuilder<> &IRB) { | |||
1420 | if (!Array->getNumElements()) | |||
1421 | return IRB.getIntN(/* width */ 1, /* value */ 0); | |||
1422 | ||||
1423 | Value *FirstItem = IRB.CreateExtractValue(Shadow, 0); | |||
1424 | Value *Aggregator = convertShadowToScalar(FirstItem, IRB); | |||
1425 | ||||
1426 | for (unsigned Idx = 1; Idx < Array->getNumElements(); Idx++) { | |||
1427 | Value *ShadowItem = IRB.CreateExtractValue(Shadow, Idx); | |||
1428 | Value *ShadowInner = convertShadowToScalar(ShadowItem, IRB); | |||
1429 | Aggregator = IRB.CreateOr(Aggregator, ShadowInner); | |||
1430 | } | |||
1431 | return Aggregator; | |||
1432 | } | |||
1433 | ||||
1434 | /// Convert a shadow value to it's flattened variant. The resulting | |||
1435 | /// shadow may not necessarily have the same bit width as the input | |||
1436 | /// value, but it will always be comparable to zero. | |||
1437 | Value *convertShadowToScalar(Value *V, IRBuilder<> &IRB) { | |||
1438 | if (StructType *Struct = dyn_cast<StructType>(V->getType())) | |||
1439 | return collapseStructShadow(Struct, V, IRB); | |||
1440 | if (ArrayType *Array = dyn_cast<ArrayType>(V->getType())) | |||
1441 | return collapseArrayShadow(Array, V, IRB); | |||
1442 | Type *Ty = V->getType(); | |||
1443 | Type *NoVecTy = getShadowTyNoVec(Ty); | |||
1444 | if (Ty == NoVecTy) return V; | |||
1445 | return IRB.CreateBitCast(V, NoVecTy); | |||
1446 | } | |||
1447 | ||||
1448 | // Convert a scalar value to an i1 by comparing with 0 | |||
1449 | Value *convertToBool(Value *V, IRBuilder<> &IRB, const Twine &name = "") { | |||
1450 | Type *VTy = V->getType(); | |||
1451 | assert(VTy->isIntegerTy())((void)0); | |||
1452 | if (VTy->getIntegerBitWidth() == 1) | |||
1453 | // Just converting a bool to a bool, so do nothing. | |||
1454 | return V; | |||
1455 | return IRB.CreateICmpNE(V, ConstantInt::get(VTy, 0), name); | |||
1456 | } | |||
1457 | ||||
1458 | /// Compute the integer shadow offset that corresponds to a given | |||
1459 | /// application address. | |||
1460 | /// | |||
1461 | /// Offset = (Addr & ~AndMask) ^ XorMask | |||
1462 | Value *getShadowPtrOffset(Value *Addr, IRBuilder<> &IRB) { | |||
1463 | Value *OffsetLong = IRB.CreatePointerCast(Addr, MS.IntptrTy); | |||
1464 | ||||
1465 | uint64_t AndMask = MS.MapParams->AndMask; | |||
1466 | if (AndMask) | |||
1467 | OffsetLong = | |||
1468 | IRB.CreateAnd(OffsetLong, ConstantInt::get(MS.IntptrTy, ~AndMask)); | |||
1469 | ||||
1470 | uint64_t XorMask = MS.MapParams->XorMask; | |||
1471 | if (XorMask) | |||
1472 | OffsetLong = | |||
1473 | IRB.CreateXor(OffsetLong, ConstantInt::get(MS.IntptrTy, XorMask)); | |||
1474 | return OffsetLong; | |||
1475 | } | |||
1476 | ||||
1477 | /// Compute the shadow and origin addresses corresponding to a given | |||
1478 | /// application address. | |||
1479 | /// | |||
1480 | /// Shadow = ShadowBase + Offset | |||
1481 | /// Origin = (OriginBase + Offset) & ~3ULL | |||
1482 | std::pair<Value *, Value *> | |||
1483 | getShadowOriginPtrUserspace(Value *Addr, IRBuilder<> &IRB, Type *ShadowTy, | |||
1484 | MaybeAlign Alignment) { | |||
1485 | Value *ShadowOffset = getShadowPtrOffset(Addr, IRB); | |||
1486 | Value *ShadowLong = ShadowOffset; | |||
1487 | uint64_t ShadowBase = MS.MapParams->ShadowBase; | |||
1488 | if (ShadowBase != 0) { | |||
1489 | ShadowLong = | |||
1490 | IRB.CreateAdd(ShadowLong, | |||
1491 | ConstantInt::get(MS.IntptrTy, ShadowBase)); | |||
1492 | } | |||
1493 | Value *ShadowPtr = | |||
1494 | IRB.CreateIntToPtr(ShadowLong, PointerType::get(ShadowTy, 0)); | |||
1495 | Value *OriginPtr = nullptr; | |||
1496 | if (MS.TrackOrigins) { | |||
1497 | Value *OriginLong = ShadowOffset; | |||
1498 | uint64_t OriginBase = MS.MapParams->OriginBase; | |||
1499 | if (OriginBase != 0) | |||
1500 | OriginLong = IRB.CreateAdd(OriginLong, | |||
1501 | ConstantInt::get(MS.IntptrTy, OriginBase)); | |||
1502 | if (!Alignment || *Alignment < kMinOriginAlignment) { | |||
1503 | uint64_t Mask = kMinOriginAlignment.value() - 1; | |||
1504 | OriginLong = | |||
1505 | IRB.CreateAnd(OriginLong, ConstantInt::get(MS.IntptrTy, ~Mask)); | |||
1506 | } | |||
1507 | OriginPtr = | |||
1508 | IRB.CreateIntToPtr(OriginLong, PointerType::get(MS.OriginTy, 0)); | |||
1509 | } | |||
1510 | return std::make_pair(ShadowPtr, OriginPtr); | |||
1511 | } | |||
1512 | ||||
1513 | std::pair<Value *, Value *> getShadowOriginPtrKernel(Value *Addr, | |||
1514 | IRBuilder<> &IRB, | |||
1515 | Type *ShadowTy, | |||
1516 | bool isStore) { | |||
1517 | Value *ShadowOriginPtrs; | |||
1518 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
1519 | int Size = DL.getTypeStoreSize(ShadowTy); | |||
1520 | ||||
1521 | FunctionCallee Getter = MS.getKmsanShadowOriginAccessFn(isStore, Size); | |||
1522 | Value *AddrCast = | |||
1523 | IRB.CreatePointerCast(Addr, PointerType::get(IRB.getInt8Ty(), 0)); | |||
1524 | if (Getter) { | |||
1525 | ShadowOriginPtrs = IRB.CreateCall(Getter, AddrCast); | |||
1526 | } else { | |||
1527 | Value *SizeVal = ConstantInt::get(MS.IntptrTy, Size); | |||
1528 | ShadowOriginPtrs = IRB.CreateCall(isStore ? MS.MsanMetadataPtrForStoreN | |||
1529 | : MS.MsanMetadataPtrForLoadN, | |||
1530 | {AddrCast, SizeVal}); | |||
1531 | } | |||
1532 | Value *ShadowPtr = IRB.CreateExtractValue(ShadowOriginPtrs, 0); | |||
1533 | ShadowPtr = IRB.CreatePointerCast(ShadowPtr, PointerType::get(ShadowTy, 0)); | |||
1534 | Value *OriginPtr = IRB.CreateExtractValue(ShadowOriginPtrs, 1); | |||
1535 | ||||
1536 | return std::make_pair(ShadowPtr, OriginPtr); | |||
1537 | } | |||
1538 | ||||
1539 | std::pair<Value *, Value *> getShadowOriginPtr(Value *Addr, IRBuilder<> &IRB, | |||
1540 | Type *ShadowTy, | |||
1541 | MaybeAlign Alignment, | |||
1542 | bool isStore) { | |||
1543 | if (MS.CompileKernel) | |||
1544 | return getShadowOriginPtrKernel(Addr, IRB, ShadowTy, isStore); | |||
1545 | return getShadowOriginPtrUserspace(Addr, IRB, ShadowTy, Alignment); | |||
1546 | } | |||
1547 | ||||
1548 | /// Compute the shadow address for a given function argument. | |||
1549 | /// | |||
1550 | /// Shadow = ParamTLS+ArgOffset. | |||
1551 | Value *getShadowPtrForArgument(Value *A, IRBuilder<> &IRB, | |||
1552 | int ArgOffset) { | |||
1553 | Value *Base = IRB.CreatePointerCast(MS.ParamTLS, MS.IntptrTy); | |||
1554 | if (ArgOffset) | |||
1555 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
1556 | return IRB.CreateIntToPtr(Base, PointerType::get(getShadowTy(A), 0), | |||
1557 | "_msarg"); | |||
1558 | } | |||
1559 | ||||
1560 | /// Compute the origin address for a given function argument. | |||
1561 | Value *getOriginPtrForArgument(Value *A, IRBuilder<> &IRB, | |||
1562 | int ArgOffset) { | |||
1563 | if (!MS.TrackOrigins) | |||
1564 | return nullptr; | |||
1565 | Value *Base = IRB.CreatePointerCast(MS.ParamOriginTLS, MS.IntptrTy); | |||
1566 | if (ArgOffset) | |||
1567 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
1568 | return IRB.CreateIntToPtr(Base, PointerType::get(MS.OriginTy, 0), | |||
1569 | "_msarg_o"); | |||
1570 | } | |||
1571 | ||||
1572 | /// Compute the shadow address for a retval. | |||
1573 | Value *getShadowPtrForRetval(Value *A, IRBuilder<> &IRB) { | |||
1574 | return IRB.CreatePointerCast(MS.RetvalTLS, | |||
1575 | PointerType::get(getShadowTy(A), 0), | |||
1576 | "_msret"); | |||
1577 | } | |||
1578 | ||||
1579 | /// Compute the origin address for a retval. | |||
1580 | Value *getOriginPtrForRetval(IRBuilder<> &IRB) { | |||
1581 | // We keep a single origin for the entire retval. Might be too optimistic. | |||
1582 | return MS.RetvalOriginTLS; | |||
1583 | } | |||
1584 | ||||
1585 | /// Set SV to be the shadow value for V. | |||
1586 | void setShadow(Value *V, Value *SV) { | |||
1587 | assert(!ShadowMap.count(V) && "Values may only have one shadow")((void)0); | |||
1588 | ShadowMap[V] = PropagateShadow ? SV : getCleanShadow(V); | |||
1589 | } | |||
1590 | ||||
1591 | /// Set Origin to be the origin value for V. | |||
1592 | void setOrigin(Value *V, Value *Origin) { | |||
1593 | if (!MS.TrackOrigins) return; | |||
1594 | assert(!OriginMap.count(V) && "Values may only have one origin")((void)0); | |||
1595 | LLVM_DEBUG(dbgs() << "ORIGIN: " << *V << " ==> " << *Origin << "\n")do { } while (false); | |||
1596 | OriginMap[V] = Origin; | |||
1597 | } | |||
1598 | ||||
1599 | Constant *getCleanShadow(Type *OrigTy) { | |||
1600 | Type *ShadowTy = getShadowTy(OrigTy); | |||
1601 | if (!ShadowTy) | |||
1602 | return nullptr; | |||
1603 | return Constant::getNullValue(ShadowTy); | |||
1604 | } | |||
1605 | ||||
1606 | /// Create a clean shadow value for a given value. | |||
1607 | /// | |||
1608 | /// Clean shadow (all zeroes) means all bits of the value are defined | |||
1609 | /// (initialized). | |||
1610 | Constant *getCleanShadow(Value *V) { | |||
1611 | return getCleanShadow(V->getType()); | |||
1612 | } | |||
1613 | ||||
1614 | /// Create a dirty shadow of a given shadow type. | |||
1615 | Constant *getPoisonedShadow(Type *ShadowTy) { | |||
1616 | assert(ShadowTy)((void)0); | |||
1617 | if (isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy)) | |||
1618 | return Constant::getAllOnesValue(ShadowTy); | |||
1619 | if (ArrayType *AT = dyn_cast<ArrayType>(ShadowTy)) { | |||
1620 | SmallVector<Constant *, 4> Vals(AT->getNumElements(), | |||
1621 | getPoisonedShadow(AT->getElementType())); | |||
1622 | return ConstantArray::get(AT, Vals); | |||
1623 | } | |||
1624 | if (StructType *ST = dyn_cast<StructType>(ShadowTy)) { | |||
1625 | SmallVector<Constant *, 4> Vals; | |||
1626 | for (unsigned i = 0, n = ST->getNumElements(); i < n; i++) | |||
1627 | Vals.push_back(getPoisonedShadow(ST->getElementType(i))); | |||
1628 | return ConstantStruct::get(ST, Vals); | |||
1629 | } | |||
1630 | llvm_unreachable("Unexpected shadow type")__builtin_unreachable(); | |||
1631 | } | |||
1632 | ||||
1633 | /// Create a dirty shadow for a given value. | |||
1634 | Constant *getPoisonedShadow(Value *V) { | |||
1635 | Type *ShadowTy = getShadowTy(V); | |||
1636 | if (!ShadowTy) | |||
1637 | return nullptr; | |||
1638 | return getPoisonedShadow(ShadowTy); | |||
1639 | } | |||
1640 | ||||
1641 | /// Create a clean (zero) origin. | |||
1642 | Value *getCleanOrigin() { | |||
1643 | return Constant::getNullValue(MS.OriginTy); | |||
1644 | } | |||
1645 | ||||
1646 | /// Get the shadow value for a given Value. | |||
1647 | /// | |||
1648 | /// This function either returns the value set earlier with setShadow, | |||
1649 | /// or extracts if from ParamTLS (for function arguments). | |||
1650 | Value *getShadow(Value *V) { | |||
1651 | if (!PropagateShadow) return getCleanShadow(V); | |||
1652 | if (Instruction *I = dyn_cast<Instruction>(V)) { | |||
1653 | if (I->getMetadata("nosanitize")) | |||
1654 | return getCleanShadow(V); | |||
1655 | // For instructions the shadow is already stored in the map. | |||
1656 | Value *Shadow = ShadowMap[V]; | |||
1657 | if (!Shadow) { | |||
1658 | LLVM_DEBUG(dbgs() << "No shadow: " << *V << "\n" << *(I->getParent()))do { } while (false); | |||
1659 | (void)I; | |||
1660 | assert(Shadow && "No shadow for a value")((void)0); | |||
1661 | } | |||
1662 | return Shadow; | |||
1663 | } | |||
1664 | if (UndefValue *U = dyn_cast<UndefValue>(V)) { | |||
1665 | Value *AllOnes = PoisonUndef ? getPoisonedShadow(V) : getCleanShadow(V); | |||
1666 | LLVM_DEBUG(dbgs() << "Undef: " << *U << " ==> " << *AllOnes << "\n")do { } while (false); | |||
1667 | (void)U; | |||
1668 | return AllOnes; | |||
1669 | } | |||
1670 | if (Argument *A = dyn_cast<Argument>(V)) { | |||
1671 | // For arguments we compute the shadow on demand and store it in the map. | |||
1672 | Value **ShadowPtr = &ShadowMap[V]; | |||
1673 | if (*ShadowPtr) | |||
1674 | return *ShadowPtr; | |||
1675 | Function *F = A->getParent(); | |||
1676 | IRBuilder<> EntryIRB(FnPrologueEnd); | |||
1677 | unsigned ArgOffset = 0; | |||
1678 | const DataLayout &DL = F->getParent()->getDataLayout(); | |||
1679 | for (auto &FArg : F->args()) { | |||
1680 | if (!FArg.getType()->isSized()) { | |||
1681 | LLVM_DEBUG(dbgs() << "Arg is not sized\n")do { } while (false); | |||
1682 | continue; | |||
1683 | } | |||
1684 | ||||
1685 | bool FArgByVal = FArg.hasByValAttr(); | |||
1686 | bool FArgNoUndef = FArg.hasAttribute(Attribute::NoUndef); | |||
1687 | bool FArgEagerCheck = ClEagerChecks && !FArgByVal && FArgNoUndef; | |||
1688 | unsigned Size = | |||
1689 | FArg.hasByValAttr() | |||
1690 | ? DL.getTypeAllocSize(FArg.getParamByValType()) | |||
1691 | : DL.getTypeAllocSize(FArg.getType()); | |||
1692 | ||||
1693 | if (A == &FArg) { | |||
1694 | bool Overflow = ArgOffset + Size > kParamTLSSize; | |||
1695 | if (FArgEagerCheck) { | |||
1696 | *ShadowPtr = getCleanShadow(V); | |||
1697 | setOrigin(A, getCleanOrigin()); | |||
1698 | continue; | |||
1699 | } else if (FArgByVal) { | |||
1700 | Value *Base = getShadowPtrForArgument(&FArg, EntryIRB, ArgOffset); | |||
1701 | // ByVal pointer itself has clean shadow. We copy the actual | |||
1702 | // argument shadow to the underlying memory. | |||
1703 | // Figure out maximal valid memcpy alignment. | |||
1704 | const Align ArgAlign = DL.getValueOrABITypeAlignment( | |||
1705 | MaybeAlign(FArg.getParamAlignment()), FArg.getParamByValType()); | |||
1706 | Value *CpShadowPtr = | |||
1707 | getShadowOriginPtr(V, EntryIRB, EntryIRB.getInt8Ty(), ArgAlign, | |||
1708 | /*isStore*/ true) | |||
1709 | .first; | |||
1710 | // TODO(glider): need to copy origins. | |||
1711 | if (Overflow) { | |||
1712 | // ParamTLS overflow. | |||
1713 | EntryIRB.CreateMemSet( | |||
1714 | CpShadowPtr, Constant::getNullValue(EntryIRB.getInt8Ty()), | |||
1715 | Size, ArgAlign); | |||
1716 | } else { | |||
1717 | const Align CopyAlign = std::min(ArgAlign, kShadowTLSAlignment); | |||
1718 | Value *Cpy = EntryIRB.CreateMemCpy(CpShadowPtr, CopyAlign, Base, | |||
1719 | CopyAlign, Size); | |||
1720 | LLVM_DEBUG(dbgs() << " ByValCpy: " << *Cpy << "\n")do { } while (false); | |||
1721 | (void)Cpy; | |||
1722 | } | |||
1723 | *ShadowPtr = getCleanShadow(V); | |||
1724 | } else { | |||
1725 | // Shadow over TLS | |||
1726 | Value *Base = getShadowPtrForArgument(&FArg, EntryIRB, ArgOffset); | |||
1727 | if (Overflow) { | |||
1728 | // ParamTLS overflow. | |||
1729 | *ShadowPtr = getCleanShadow(V); | |||
1730 | } else { | |||
1731 | *ShadowPtr = EntryIRB.CreateAlignedLoad(getShadowTy(&FArg), Base, | |||
1732 | kShadowTLSAlignment); | |||
1733 | } | |||
1734 | } | |||
1735 | LLVM_DEBUG(dbgs()do { } while (false) | |||
1736 | << " ARG: " << FArg << " ==> " << **ShadowPtr << "\n")do { } while (false); | |||
1737 | if (MS.TrackOrigins && !Overflow) { | |||
1738 | Value *OriginPtr = | |||
1739 | getOriginPtrForArgument(&FArg, EntryIRB, ArgOffset); | |||
1740 | setOrigin(A, EntryIRB.CreateLoad(MS.OriginTy, OriginPtr)); | |||
1741 | } else { | |||
1742 | setOrigin(A, getCleanOrigin()); | |||
1743 | } | |||
1744 | ||||
1745 | break; | |||
1746 | } | |||
1747 | ||||
1748 | if (!FArgEagerCheck) | |||
1749 | ArgOffset += alignTo(Size, kShadowTLSAlignment); | |||
1750 | } | |||
1751 | assert(*ShadowPtr && "Could not find shadow for an argument")((void)0); | |||
1752 | return *ShadowPtr; | |||
1753 | } | |||
1754 | // For everything else the shadow is zero. | |||
1755 | return getCleanShadow(V); | |||
1756 | } | |||
1757 | ||||
1758 | /// Get the shadow for i-th argument of the instruction I. | |||
1759 | Value *getShadow(Instruction *I, int i) { | |||
1760 | return getShadow(I->getOperand(i)); | |||
1761 | } | |||
1762 | ||||
1763 | /// Get the origin for a value. | |||
1764 | Value *getOrigin(Value *V) { | |||
1765 | if (!MS.TrackOrigins) return nullptr; | |||
1766 | if (!PropagateShadow) return getCleanOrigin(); | |||
1767 | if (isa<Constant>(V)) return getCleanOrigin(); | |||
1768 | assert((isa<Instruction>(V) || isa<Argument>(V)) &&((void)0) | |||
1769 | "Unexpected value type in getOrigin()")((void)0); | |||
1770 | if (Instruction *I = dyn_cast<Instruction>(V)) { | |||
1771 | if (I->getMetadata("nosanitize")) | |||
1772 | return getCleanOrigin(); | |||
1773 | } | |||
1774 | Value *Origin = OriginMap[V]; | |||
1775 | assert(Origin && "Missing origin")((void)0); | |||
1776 | return Origin; | |||
1777 | } | |||
1778 | ||||
1779 | /// Get the origin for i-th argument of the instruction I. | |||
1780 | Value *getOrigin(Instruction *I, int i) { | |||
1781 | return getOrigin(I->getOperand(i)); | |||
1782 | } | |||
1783 | ||||
1784 | /// Remember the place where a shadow check should be inserted. | |||
1785 | /// | |||
1786 | /// This location will be later instrumented with a check that will print a | |||
1787 | /// UMR warning in runtime if the shadow value is not 0. | |||
1788 | void insertShadowCheck(Value *Shadow, Value *Origin, Instruction *OrigIns) { | |||
1789 | assert(Shadow)((void)0); | |||
1790 | if (!InsertChecks) return; | |||
1791 | #ifndef NDEBUG1 | |||
1792 | Type *ShadowTy = Shadow->getType(); | |||
1793 | assert((isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy) ||((void)0) | |||
1794 | isa<StructType>(ShadowTy) || isa<ArrayType>(ShadowTy)) &&((void)0) | |||
1795 | "Can only insert checks for integer, vector, and aggregate shadow "((void)0) | |||
1796 | "types")((void)0); | |||
1797 | #endif | |||
1798 | InstrumentationList.push_back( | |||
1799 | ShadowOriginAndInsertPoint(Shadow, Origin, OrigIns)); | |||
1800 | } | |||
1801 | ||||
1802 | /// Remember the place where a shadow check should be inserted. | |||
1803 | /// | |||
1804 | /// This location will be later instrumented with a check that will print a | |||
1805 | /// UMR warning in runtime if the value is not fully defined. | |||
1806 | void insertShadowCheck(Value *Val, Instruction *OrigIns) { | |||
1807 | assert(Val)((void)0); | |||
1808 | Value *Shadow, *Origin; | |||
1809 | if (ClCheckConstantShadow) { | |||
1810 | Shadow = getShadow(Val); | |||
1811 | if (!Shadow) return; | |||
1812 | Origin = getOrigin(Val); | |||
1813 | } else { | |||
1814 | Shadow = dyn_cast_or_null<Instruction>(getShadow(Val)); | |||
1815 | if (!Shadow) return; | |||
1816 | Origin = dyn_cast_or_null<Instruction>(getOrigin(Val)); | |||
1817 | } | |||
1818 | insertShadowCheck(Shadow, Origin, OrigIns); | |||
1819 | } | |||
1820 | ||||
1821 | AtomicOrdering addReleaseOrdering(AtomicOrdering a) { | |||
1822 | switch (a) { | |||
1823 | case AtomicOrdering::NotAtomic: | |||
1824 | return AtomicOrdering::NotAtomic; | |||
1825 | case AtomicOrdering::Unordered: | |||
1826 | case AtomicOrdering::Monotonic: | |||
1827 | case AtomicOrdering::Release: | |||
1828 | return AtomicOrdering::Release; | |||
1829 | case AtomicOrdering::Acquire: | |||
1830 | case AtomicOrdering::AcquireRelease: | |||
1831 | return AtomicOrdering::AcquireRelease; | |||
1832 | case AtomicOrdering::SequentiallyConsistent: | |||
1833 | return AtomicOrdering::SequentiallyConsistent; | |||
1834 | } | |||
1835 | llvm_unreachable("Unknown ordering")__builtin_unreachable(); | |||
1836 | } | |||
1837 | ||||
1838 | Value *makeAddReleaseOrderingTable(IRBuilder<> &IRB) { | |||
1839 | constexpr int NumOrderings = (int)AtomicOrderingCABI::seq_cst + 1; | |||
1840 | uint32_t OrderingTable[NumOrderings] = {}; | |||
1841 | ||||
1842 | OrderingTable[(int)AtomicOrderingCABI::relaxed] = | |||
1843 | OrderingTable[(int)AtomicOrderingCABI::release] = | |||
1844 | (int)AtomicOrderingCABI::release; | |||
1845 | OrderingTable[(int)AtomicOrderingCABI::consume] = | |||
1846 | OrderingTable[(int)AtomicOrderingCABI::acquire] = | |||
1847 | OrderingTable[(int)AtomicOrderingCABI::acq_rel] = | |||
1848 | (int)AtomicOrderingCABI::acq_rel; | |||
1849 | OrderingTable[(int)AtomicOrderingCABI::seq_cst] = | |||
1850 | (int)AtomicOrderingCABI::seq_cst; | |||
1851 | ||||
1852 | return ConstantDataVector::get(IRB.getContext(), | |||
1853 | makeArrayRef(OrderingTable, NumOrderings)); | |||
1854 | } | |||
1855 | ||||
1856 | AtomicOrdering addAcquireOrdering(AtomicOrdering a) { | |||
1857 | switch (a) { | |||
1858 | case AtomicOrdering::NotAtomic: | |||
1859 | return AtomicOrdering::NotAtomic; | |||
1860 | case AtomicOrdering::Unordered: | |||
1861 | case AtomicOrdering::Monotonic: | |||
1862 | case AtomicOrdering::Acquire: | |||
1863 | return AtomicOrdering::Acquire; | |||
1864 | case AtomicOrdering::Release: | |||
1865 | case AtomicOrdering::AcquireRelease: | |||
1866 | return AtomicOrdering::AcquireRelease; | |||
1867 | case AtomicOrdering::SequentiallyConsistent: | |||
1868 | return AtomicOrdering::SequentiallyConsistent; | |||
1869 | } | |||
1870 | llvm_unreachable("Unknown ordering")__builtin_unreachable(); | |||
1871 | } | |||
1872 | ||||
1873 | Value *makeAddAcquireOrderingTable(IRBuilder<> &IRB) { | |||
1874 | constexpr int NumOrderings = (int)AtomicOrderingCABI::seq_cst + 1; | |||
1875 | uint32_t OrderingTable[NumOrderings] = {}; | |||
1876 | ||||
1877 | OrderingTable[(int)AtomicOrderingCABI::relaxed] = | |||
1878 | OrderingTable[(int)AtomicOrderingCABI::acquire] = | |||
1879 | OrderingTable[(int)AtomicOrderingCABI::consume] = | |||
1880 | (int)AtomicOrderingCABI::acquire; | |||
1881 | OrderingTable[(int)AtomicOrderingCABI::release] = | |||
1882 | OrderingTable[(int)AtomicOrderingCABI::acq_rel] = | |||
1883 | (int)AtomicOrderingCABI::acq_rel; | |||
1884 | OrderingTable[(int)AtomicOrderingCABI::seq_cst] = | |||
1885 | (int)AtomicOrderingCABI::seq_cst; | |||
1886 | ||||
1887 | return ConstantDataVector::get(IRB.getContext(), | |||
1888 | makeArrayRef(OrderingTable, NumOrderings)); | |||
1889 | } | |||
1890 | ||||
1891 | // ------------------- Visitors. | |||
1892 | using InstVisitor<MemorySanitizerVisitor>::visit; | |||
1893 | void visit(Instruction &I) { | |||
1894 | if (I.getMetadata("nosanitize")) | |||
1895 | return; | |||
1896 | // Don't want to visit if we're in the prologue | |||
1897 | if (isInPrologue(I)) | |||
1898 | return; | |||
1899 | InstVisitor<MemorySanitizerVisitor>::visit(I); | |||
1900 | } | |||
1901 | ||||
1902 | /// Instrument LoadInst | |||
1903 | /// | |||
1904 | /// Loads the corresponding shadow and (optionally) origin. | |||
1905 | /// Optionally, checks that the load address is fully defined. | |||
1906 | void visitLoadInst(LoadInst &I) { | |||
1907 | assert(I.getType()->isSized() && "Load type must have size")((void)0); | |||
1908 | assert(!I.getMetadata("nosanitize"))((void)0); | |||
1909 | IRBuilder<> IRB(I.getNextNode()); | |||
1910 | Type *ShadowTy = getShadowTy(&I); | |||
1911 | Value *Addr = I.getPointerOperand(); | |||
1912 | Value *ShadowPtr = nullptr, *OriginPtr = nullptr; | |||
1913 | const Align Alignment = assumeAligned(I.getAlignment()); | |||
1914 | if (PropagateShadow) { | |||
1915 | std::tie(ShadowPtr, OriginPtr) = | |||
1916 | getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ false); | |||
1917 | setShadow(&I, | |||
1918 | IRB.CreateAlignedLoad(ShadowTy, ShadowPtr, Alignment, "_msld")); | |||
1919 | } else { | |||
1920 | setShadow(&I, getCleanShadow(&I)); | |||
1921 | } | |||
1922 | ||||
1923 | if (ClCheckAccessAddress) | |||
1924 | insertShadowCheck(I.getPointerOperand(), &I); | |||
1925 | ||||
1926 | if (I.isAtomic()) | |||
1927 | I.setOrdering(addAcquireOrdering(I.getOrdering())); | |||
1928 | ||||
1929 | if (MS.TrackOrigins) { | |||
1930 | if (PropagateShadow) { | |||
1931 | const Align OriginAlignment = std::max(kMinOriginAlignment, Alignment); | |||
1932 | setOrigin( | |||
1933 | &I, IRB.CreateAlignedLoad(MS.OriginTy, OriginPtr, OriginAlignment)); | |||
1934 | } else { | |||
1935 | setOrigin(&I, getCleanOrigin()); | |||
1936 | } | |||
1937 | } | |||
1938 | } | |||
1939 | ||||
1940 | /// Instrument StoreInst | |||
1941 | /// | |||
1942 | /// Stores the corresponding shadow and (optionally) origin. | |||
1943 | /// Optionally, checks that the store address is fully defined. | |||
1944 | void visitStoreInst(StoreInst &I) { | |||
1945 | StoreList.push_back(&I); | |||
1946 | if (ClCheckAccessAddress) | |||
1947 | insertShadowCheck(I.getPointerOperand(), &I); | |||
1948 | } | |||
1949 | ||||
1950 | void handleCASOrRMW(Instruction &I) { | |||
1951 | assert(isa<AtomicRMWInst>(I) || isa<AtomicCmpXchgInst>(I))((void)0); | |||
1952 | ||||
1953 | IRBuilder<> IRB(&I); | |||
1954 | Value *Addr = I.getOperand(0); | |||
1955 | Value *Val = I.getOperand(1); | |||
1956 | Value *ShadowPtr = getShadowOriginPtr(Addr, IRB, Val->getType(), Align(1), | |||
1957 | /*isStore*/ true) | |||
1958 | .first; | |||
1959 | ||||
1960 | if (ClCheckAccessAddress) | |||
1961 | insertShadowCheck(Addr, &I); | |||
1962 | ||||
1963 | // Only test the conditional argument of cmpxchg instruction. | |||
1964 | // The other argument can potentially be uninitialized, but we can not | |||
1965 | // detect this situation reliably without possible false positives. | |||
1966 | if (isa<AtomicCmpXchgInst>(I)) | |||
1967 | insertShadowCheck(Val, &I); | |||
1968 | ||||
1969 | IRB.CreateStore(getCleanShadow(Val), ShadowPtr); | |||
1970 | ||||
1971 | setShadow(&I, getCleanShadow(&I)); | |||
1972 | setOrigin(&I, getCleanOrigin()); | |||
1973 | } | |||
1974 | ||||
1975 | void visitAtomicRMWInst(AtomicRMWInst &I) { | |||
1976 | handleCASOrRMW(I); | |||
1977 | I.setOrdering(addReleaseOrdering(I.getOrdering())); | |||
1978 | } | |||
1979 | ||||
1980 | void visitAtomicCmpXchgInst(AtomicCmpXchgInst &I) { | |||
1981 | handleCASOrRMW(I); | |||
1982 | I.setSuccessOrdering(addReleaseOrdering(I.getSuccessOrdering())); | |||
1983 | } | |||
1984 | ||||
1985 | // Vector manipulation. | |||
1986 | void visitExtractElementInst(ExtractElementInst &I) { | |||
1987 | insertShadowCheck(I.getOperand(1), &I); | |||
1988 | IRBuilder<> IRB(&I); | |||
1989 | setShadow(&I, IRB.CreateExtractElement(getShadow(&I, 0), I.getOperand(1), | |||
1990 | "_msprop")); | |||
1991 | setOrigin(&I, getOrigin(&I, 0)); | |||
1992 | } | |||
1993 | ||||
1994 | void visitInsertElementInst(InsertElementInst &I) { | |||
1995 | insertShadowCheck(I.getOperand(2), &I); | |||
1996 | IRBuilder<> IRB(&I); | |||
1997 | setShadow(&I, IRB.CreateInsertElement(getShadow(&I, 0), getShadow(&I, 1), | |||
1998 | I.getOperand(2), "_msprop")); | |||
1999 | setOriginForNaryOp(I); | |||
2000 | } | |||
2001 | ||||
2002 | void visitShuffleVectorInst(ShuffleVectorInst &I) { | |||
2003 | IRBuilder<> IRB(&I); | |||
2004 | setShadow(&I, IRB.CreateShuffleVector(getShadow(&I, 0), getShadow(&I, 1), | |||
2005 | I.getShuffleMask(), "_msprop")); | |||
2006 | setOriginForNaryOp(I); | |||
2007 | } | |||
2008 | ||||
2009 | // Casts. | |||
2010 | void visitSExtInst(SExtInst &I) { | |||
2011 | IRBuilder<> IRB(&I); | |||
2012 | setShadow(&I, IRB.CreateSExt(getShadow(&I, 0), I.getType(), "_msprop")); | |||
2013 | setOrigin(&I, getOrigin(&I, 0)); | |||
2014 | } | |||
2015 | ||||
2016 | void visitZExtInst(ZExtInst &I) { | |||
2017 | IRBuilder<> IRB(&I); | |||
2018 | setShadow(&I, IRB.CreateZExt(getShadow(&I, 0), I.getType(), "_msprop")); | |||
2019 | setOrigin(&I, getOrigin(&I, 0)); | |||
2020 | } | |||
2021 | ||||
2022 | void visitTruncInst(TruncInst &I) { | |||
2023 | IRBuilder<> IRB(&I); | |||
2024 | setShadow(&I, IRB.CreateTrunc(getShadow(&I, 0), I.getType(), "_msprop")); | |||
2025 | setOrigin(&I, getOrigin(&I, 0)); | |||
2026 | } | |||
2027 | ||||
2028 | void visitBitCastInst(BitCastInst &I) { | |||
2029 | // Special case: if this is the bitcast (there is exactly 1 allowed) between | |||
2030 | // a musttail call and a ret, don't instrument. New instructions are not | |||
2031 | // allowed after a musttail call. | |||
2032 | if (auto *CI = dyn_cast<CallInst>(I.getOperand(0))) | |||
2033 | if (CI->isMustTailCall()) | |||
2034 | return; | |||
2035 | IRBuilder<> IRB(&I); | |||
2036 | setShadow(&I, IRB.CreateBitCast(getShadow(&I, 0), getShadowTy(&I))); | |||
2037 | setOrigin(&I, getOrigin(&I, 0)); | |||
2038 | } | |||
2039 | ||||
2040 | void visitPtrToIntInst(PtrToIntInst &I) { | |||
2041 | IRBuilder<> IRB(&I); | |||
2042 | setShadow(&I, IRB.CreateIntCast(getShadow(&I, 0), getShadowTy(&I), false, | |||
2043 | "_msprop_ptrtoint")); | |||
2044 | setOrigin(&I, getOrigin(&I, 0)); | |||
2045 | } | |||
2046 | ||||
2047 | void visitIntToPtrInst(IntToPtrInst &I) { | |||
2048 | IRBuilder<> IRB(&I); | |||
2049 | setShadow(&I, IRB.CreateIntCast(getShadow(&I, 0), getShadowTy(&I), false, | |||
2050 | "_msprop_inttoptr")); | |||
2051 | setOrigin(&I, getOrigin(&I, 0)); | |||
2052 | } | |||
2053 | ||||
2054 | void visitFPToSIInst(CastInst& I) { handleShadowOr(I); } | |||
2055 | void visitFPToUIInst(CastInst& I) { handleShadowOr(I); } | |||
2056 | void visitSIToFPInst(CastInst& I) { handleShadowOr(I); } | |||
2057 | void visitUIToFPInst(CastInst& I) { handleShadowOr(I); } | |||
2058 | void visitFPExtInst(CastInst& I) { handleShadowOr(I); } | |||
2059 | void visitFPTruncInst(CastInst& I) { handleShadowOr(I); } | |||
2060 | ||||
2061 | /// Propagate shadow for bitwise AND. | |||
2062 | /// | |||
2063 | /// This code is exact, i.e. if, for example, a bit in the left argument | |||
2064 | /// is defined and 0, then neither the value not definedness of the | |||
2065 | /// corresponding bit in B don't affect the resulting shadow. | |||
2066 | void visitAnd(BinaryOperator &I) { | |||
2067 | IRBuilder<> IRB(&I); | |||
2068 | // "And" of 0 and a poisoned value results in unpoisoned value. | |||
2069 | // 1&1 => 1; 0&1 => 0; p&1 => p; | |||
2070 | // 1&0 => 0; 0&0 => 0; p&0 => 0; | |||
2071 | // 1&p => p; 0&p => 0; p&p => p; | |||
2072 | // S = (S1 & S2) | (V1 & S2) | (S1 & V2) | |||
2073 | Value *S1 = getShadow(&I, 0); | |||
2074 | Value *S2 = getShadow(&I, 1); | |||
2075 | Value *V1 = I.getOperand(0); | |||
2076 | Value *V2 = I.getOperand(1); | |||
2077 | if (V1->getType() != S1->getType()) { | |||
2078 | V1 = IRB.CreateIntCast(V1, S1->getType(), false); | |||
2079 | V2 = IRB.CreateIntCast(V2, S2->getType(), false); | |||
2080 | } | |||
2081 | Value *S1S2 = IRB.CreateAnd(S1, S2); | |||
2082 | Value *V1S2 = IRB.CreateAnd(V1, S2); | |||
2083 | Value *S1V2 = IRB.CreateAnd(S1, V2); | |||
2084 | setShadow(&I, IRB.CreateOr({S1S2, V1S2, S1V2})); | |||
2085 | setOriginForNaryOp(I); | |||
2086 | } | |||
2087 | ||||
2088 | void visitOr(BinaryOperator &I) { | |||
2089 | IRBuilder<> IRB(&I); | |||
2090 | // "Or" of 1 and a poisoned value results in unpoisoned value. | |||
2091 | // 1|1 => 1; 0|1 => 1; p|1 => 1; | |||
2092 | // 1|0 => 1; 0|0 => 0; p|0 => p; | |||
2093 | // 1|p => 1; 0|p => p; p|p => p; | |||
2094 | // S = (S1 & S2) | (~V1 & S2) | (S1 & ~V2) | |||
2095 | Value *S1 = getShadow(&I, 0); | |||
2096 | Value *S2 = getShadow(&I, 1); | |||
2097 | Value *V1 = IRB.CreateNot(I.getOperand(0)); | |||
2098 | Value *V2 = IRB.CreateNot(I.getOperand(1)); | |||
2099 | if (V1->getType() != S1->getType()) { | |||
2100 | V1 = IRB.CreateIntCast(V1, S1->getType(), false); | |||
2101 | V2 = IRB.CreateIntCast(V2, S2->getType(), false); | |||
2102 | } | |||
2103 | Value *S1S2 = IRB.CreateAnd(S1, S2); | |||
2104 | Value *V1S2 = IRB.CreateAnd(V1, S2); | |||
2105 | Value *S1V2 = IRB.CreateAnd(S1, V2); | |||
2106 | setShadow(&I, IRB.CreateOr({S1S2, V1S2, S1V2})); | |||
2107 | setOriginForNaryOp(I); | |||
2108 | } | |||
2109 | ||||
2110 | /// Default propagation of shadow and/or origin. | |||
2111 | /// | |||
2112 | /// This class implements the general case of shadow propagation, used in all | |||
2113 | /// cases where we don't know and/or don't care about what the operation | |||
2114 | /// actually does. It converts all input shadow values to a common type | |||
2115 | /// (extending or truncating as necessary), and bitwise OR's them. | |||
2116 | /// | |||
2117 | /// This is much cheaper than inserting checks (i.e. requiring inputs to be | |||
2118 | /// fully initialized), and less prone to false positives. | |||
2119 | /// | |||
2120 | /// This class also implements the general case of origin propagation. For a | |||
2121 | /// Nary operation, result origin is set to the origin of an argument that is | |||
2122 | /// not entirely initialized. If there is more than one such arguments, the | |||
2123 | /// rightmost of them is picked. It does not matter which one is picked if all | |||
2124 | /// arguments are initialized. | |||
2125 | template <bool CombineShadow> | |||
2126 | class Combiner { | |||
2127 | Value *Shadow = nullptr; | |||
2128 | Value *Origin = nullptr; | |||
2129 | IRBuilder<> &IRB; | |||
2130 | MemorySanitizerVisitor *MSV; | |||
2131 | ||||
2132 | public: | |||
2133 | Combiner(MemorySanitizerVisitor *MSV, IRBuilder<> &IRB) | |||
2134 | : IRB(IRB), MSV(MSV) {} | |||
2135 | ||||
2136 | /// Add a pair of shadow and origin values to the mix. | |||
2137 | Combiner &Add(Value *OpShadow, Value *OpOrigin) { | |||
2138 | if (CombineShadow) { | |||
2139 | assert(OpShadow)((void)0); | |||
2140 | if (!Shadow) | |||
2141 | Shadow = OpShadow; | |||
2142 | else { | |||
2143 | OpShadow = MSV->CreateShadowCast(IRB, OpShadow, Shadow->getType()); | |||
2144 | Shadow = IRB.CreateOr(Shadow, OpShadow, "_msprop"); | |||
2145 | } | |||
2146 | } | |||
2147 | ||||
2148 | if (MSV->MS.TrackOrigins) { | |||
2149 | assert(OpOrigin)((void)0); | |||
2150 | if (!Origin) { | |||
2151 | Origin = OpOrigin; | |||
2152 | } else { | |||
2153 | Constant *ConstOrigin = dyn_cast<Constant>(OpOrigin); | |||
2154 | // No point in adding something that might result in 0 origin value. | |||
2155 | if (!ConstOrigin || !ConstOrigin->isNullValue()) { | |||
2156 | Value *FlatShadow = MSV->convertShadowToScalar(OpShadow, IRB); | |||
2157 | Value *Cond = | |||
2158 | IRB.CreateICmpNE(FlatShadow, MSV->getCleanShadow(FlatShadow)); | |||
2159 | Origin = IRB.CreateSelect(Cond, OpOrigin, Origin); | |||
2160 | } | |||
2161 | } | |||
2162 | } | |||
2163 | return *this; | |||
2164 | } | |||
2165 | ||||
2166 | /// Add an application value to the mix. | |||
2167 | Combiner &Add(Value *V) { | |||
2168 | Value *OpShadow = MSV->getShadow(V); | |||
2169 | Value *OpOrigin = MSV->MS.TrackOrigins ? MSV->getOrigin(V) : nullptr; | |||
2170 | return Add(OpShadow, OpOrigin); | |||
2171 | } | |||
2172 | ||||
2173 | /// Set the current combined values as the given instruction's shadow | |||
2174 | /// and origin. | |||
2175 | void Done(Instruction *I) { | |||
2176 | if (CombineShadow) { | |||
2177 | assert(Shadow)((void)0); | |||
2178 | Shadow = MSV->CreateShadowCast(IRB, Shadow, MSV->getShadowTy(I)); | |||
2179 | MSV->setShadow(I, Shadow); | |||
2180 | } | |||
2181 | if (MSV->MS.TrackOrigins) { | |||
2182 | assert(Origin)((void)0); | |||
2183 | MSV->setOrigin(I, Origin); | |||
2184 | } | |||
2185 | } | |||
2186 | }; | |||
2187 | ||||
2188 | using ShadowAndOriginCombiner = Combiner<true>; | |||
2189 | using OriginCombiner = Combiner<false>; | |||
2190 | ||||
2191 | /// Propagate origin for arbitrary operation. | |||
2192 | void setOriginForNaryOp(Instruction &I) { | |||
2193 | if (!MS.TrackOrigins) return; | |||
2194 | IRBuilder<> IRB(&I); | |||
2195 | OriginCombiner OC(this, IRB); | |||
2196 | for (Use &Op : I.operands()) | |||
2197 | OC.Add(Op.get()); | |||
2198 | OC.Done(&I); | |||
2199 | } | |||
2200 | ||||
2201 | size_t VectorOrPrimitiveTypeSizeInBits(Type *Ty) { | |||
2202 | assert(!(Ty->isVectorTy() && Ty->getScalarType()->isPointerTy()) &&((void)0) | |||
2203 | "Vector of pointers is not a valid shadow type")((void)0); | |||
2204 | return Ty->isVectorTy() ? cast<FixedVectorType>(Ty)->getNumElements() * | |||
2205 | Ty->getScalarSizeInBits() | |||
2206 | : Ty->getPrimitiveSizeInBits(); | |||
2207 | } | |||
2208 | ||||
2209 | /// Cast between two shadow types, extending or truncating as | |||
2210 | /// necessary. | |||
2211 | Value *CreateShadowCast(IRBuilder<> &IRB, Value *V, Type *dstTy, | |||
2212 | bool Signed = false) { | |||
2213 | Type *srcTy = V->getType(); | |||
| ||||
2214 | size_t srcSizeInBits = VectorOrPrimitiveTypeSizeInBits(srcTy); | |||
2215 | size_t dstSizeInBits = VectorOrPrimitiveTypeSizeInBits(dstTy); | |||
2216 | if (srcSizeInBits > 1 && dstSizeInBits == 1) | |||
2217 | return IRB.CreateICmpNE(V, getCleanShadow(V)); | |||
2218 | ||||
2219 | if (dstTy->isIntegerTy() && srcTy->isIntegerTy()) | |||
2220 | return IRB.CreateIntCast(V, dstTy, Signed); | |||
2221 | if (dstTy->isVectorTy() && srcTy->isVectorTy() && | |||
2222 | cast<FixedVectorType>(dstTy)->getNumElements() == | |||
2223 | cast<FixedVectorType>(srcTy)->getNumElements()) | |||
2224 | return IRB.CreateIntCast(V, dstTy, Signed); | |||
2225 | Value *V1 = IRB.CreateBitCast(V, Type::getIntNTy(*MS.C, srcSizeInBits)); | |||
2226 | Value *V2 = | |||
2227 | IRB.CreateIntCast(V1, Type::getIntNTy(*MS.C, dstSizeInBits), Signed); | |||
2228 | return IRB.CreateBitCast(V2, dstTy); | |||
2229 | // TODO: handle struct types. | |||
2230 | } | |||
2231 | ||||
2232 | /// Cast an application value to the type of its own shadow. | |||
2233 | Value *CreateAppToShadowCast(IRBuilder<> &IRB, Value *V) { | |||
2234 | Type *ShadowTy = getShadowTy(V); | |||
2235 | if (V->getType() == ShadowTy) | |||
2236 | return V; | |||
2237 | if (V->getType()->isPtrOrPtrVectorTy()) | |||
2238 | return IRB.CreatePtrToInt(V, ShadowTy); | |||
2239 | else | |||
2240 | return IRB.CreateBitCast(V, ShadowTy); | |||
2241 | } | |||
2242 | ||||
2243 | /// Propagate shadow for arbitrary operation. | |||
2244 | void handleShadowOr(Instruction &I) { | |||
2245 | IRBuilder<> IRB(&I); | |||
2246 | ShadowAndOriginCombiner SC(this, IRB); | |||
2247 | for (Use &Op : I.operands()) | |||
2248 | SC.Add(Op.get()); | |||
2249 | SC.Done(&I); | |||
2250 | } | |||
2251 | ||||
2252 | void visitFNeg(UnaryOperator &I) { handleShadowOr(I); } | |||
2253 | ||||
2254 | // Handle multiplication by constant. | |||
2255 | // | |||
2256 | // Handle a special case of multiplication by constant that may have one or | |||
2257 | // more zeros in the lower bits. This makes corresponding number of lower bits | |||
2258 | // of the result zero as well. We model it by shifting the other operand | |||
2259 | // shadow left by the required number of bits. Effectively, we transform | |||
2260 | // (X * (A * 2**B)) to ((X << B) * A) and instrument (X << B) as (Sx << B). | |||
2261 | // We use multiplication by 2**N instead of shift to cover the case of | |||
2262 | // multiplication by 0, which may occur in some elements of a vector operand. | |||
2263 | void handleMulByConstant(BinaryOperator &I, Constant *ConstArg, | |||
2264 | Value *OtherArg) { | |||
2265 | Constant *ShadowMul; | |||
2266 | Type *Ty = ConstArg->getType(); | |||
2267 | if (auto *VTy = dyn_cast<VectorType>(Ty)) { | |||
2268 | unsigned NumElements = cast<FixedVectorType>(VTy)->getNumElements(); | |||
2269 | Type *EltTy = VTy->getElementType(); | |||
2270 | SmallVector<Constant *, 16> Elements; | |||
2271 | for (unsigned Idx = 0; Idx < NumElements; ++Idx) { | |||
2272 | if (ConstantInt *Elt = | |||
2273 | dyn_cast<ConstantInt>(ConstArg->getAggregateElement(Idx))) { | |||
2274 | const APInt &V = Elt->getValue(); | |||
2275 | APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros(); | |||
2276 | Elements.push_back(ConstantInt::get(EltTy, V2)); | |||
2277 | } else { | |||
2278 | Elements.push_back(ConstantInt::get(EltTy, 1)); | |||
2279 | } | |||
2280 | } | |||
2281 | ShadowMul = ConstantVector::get(Elements); | |||
2282 | } else { | |||
2283 | if (ConstantInt *Elt = dyn_cast<ConstantInt>(ConstArg)) { | |||
2284 | const APInt &V = Elt->getValue(); | |||
2285 | APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros(); | |||
2286 | ShadowMul = ConstantInt::get(Ty, V2); | |||
2287 | } else { | |||
2288 | ShadowMul = ConstantInt::get(Ty, 1); | |||
2289 | } | |||
2290 | } | |||
2291 | ||||
2292 | IRBuilder<> IRB(&I); | |||
2293 | setShadow(&I, | |||
2294 | IRB.CreateMul(getShadow(OtherArg), ShadowMul, "msprop_mul_cst")); | |||
2295 | setOrigin(&I, getOrigin(OtherArg)); | |||
2296 | } | |||
2297 | ||||
2298 | void visitMul(BinaryOperator &I) { | |||
2299 | Constant *constOp0 = dyn_cast<Constant>(I.getOperand(0)); | |||
2300 | Constant *constOp1 = dyn_cast<Constant>(I.getOperand(1)); | |||
2301 | if (constOp0 && !constOp1) | |||
2302 | handleMulByConstant(I, constOp0, I.getOperand(1)); | |||
2303 | else if (constOp1 && !constOp0) | |||
2304 | handleMulByConstant(I, constOp1, I.getOperand(0)); | |||
2305 | else | |||
2306 | handleShadowOr(I); | |||
2307 | } | |||
2308 | ||||
2309 | void visitFAdd(BinaryOperator &I) { handleShadowOr(I); } | |||
2310 | void visitFSub(BinaryOperator &I) { handleShadowOr(I); } | |||
2311 | void visitFMul(BinaryOperator &I) { handleShadowOr(I); } | |||
2312 | void visitAdd(BinaryOperator &I) { handleShadowOr(I); } | |||
2313 | void visitSub(BinaryOperator &I) { handleShadowOr(I); } | |||
2314 | void visitXor(BinaryOperator &I) { handleShadowOr(I); } | |||
2315 | ||||
2316 | void handleIntegerDiv(Instruction &I) { | |||
2317 | IRBuilder<> IRB(&I); | |||
2318 | // Strict on the second argument. | |||
2319 | insertShadowCheck(I.getOperand(1), &I); | |||
2320 | setShadow(&I, getShadow(&I, 0)); | |||
2321 | setOrigin(&I, getOrigin(&I, 0)); | |||
2322 | } | |||
2323 | ||||
2324 | void visitUDiv(BinaryOperator &I) { handleIntegerDiv(I); } | |||
2325 | void visitSDiv(BinaryOperator &I) { handleIntegerDiv(I); } | |||
2326 | void visitURem(BinaryOperator &I) { handleIntegerDiv(I); } | |||
2327 | void visitSRem(BinaryOperator &I) { handleIntegerDiv(I); } | |||
2328 | ||||
2329 | // Floating point division is side-effect free. We can not require that the | |||
2330 | // divisor is fully initialized and must propagate shadow. See PR37523. | |||
2331 | void visitFDiv(BinaryOperator &I) { handleShadowOr(I); } | |||
2332 | void visitFRem(BinaryOperator &I) { handleShadowOr(I); } | |||
2333 | ||||
2334 | /// Instrument == and != comparisons. | |||
2335 | /// | |||
2336 | /// Sometimes the comparison result is known even if some of the bits of the | |||
2337 | /// arguments are not. | |||
2338 | void handleEqualityComparison(ICmpInst &I) { | |||
2339 | IRBuilder<> IRB(&I); | |||
2340 | Value *A = I.getOperand(0); | |||
2341 | Value *B = I.getOperand(1); | |||
2342 | Value *Sa = getShadow(A); | |||
2343 | Value *Sb = getShadow(B); | |||
2344 | ||||
2345 | // Get rid of pointers and vectors of pointers. | |||
2346 | // For ints (and vectors of ints), types of A and Sa match, | |||
2347 | // and this is a no-op. | |||
2348 | A = IRB.CreatePointerCast(A, Sa->getType()); | |||
2349 | B = IRB.CreatePointerCast(B, Sb->getType()); | |||
2350 | ||||
2351 | // A == B <==> (C = A^B) == 0 | |||
2352 | // A != B <==> (C = A^B) != 0 | |||
2353 | // Sc = Sa | Sb | |||
2354 | Value *C = IRB.CreateXor(A, B); | |||
2355 | Value *Sc = IRB.CreateOr(Sa, Sb); | |||
2356 | // Now dealing with i = (C == 0) comparison (or C != 0, does not matter now) | |||
2357 | // Result is defined if one of the following is true | |||
2358 | // * there is a defined 1 bit in C | |||
2359 | // * C is fully defined | |||
2360 | // Si = !(C & ~Sc) && Sc | |||
2361 | Value *Zero = Constant::getNullValue(Sc->getType()); | |||
2362 | Value *MinusOne = Constant::getAllOnesValue(Sc->getType()); | |||
2363 | Value *Si = | |||
2364 | IRB.CreateAnd(IRB.CreateICmpNE(Sc, Zero), | |||
2365 | IRB.CreateICmpEQ( | |||
2366 | IRB.CreateAnd(IRB.CreateXor(Sc, MinusOne), C), Zero)); | |||
2367 | Si->setName("_msprop_icmp"); | |||
2368 | setShadow(&I, Si); | |||
2369 | setOriginForNaryOp(I); | |||
2370 | } | |||
2371 | ||||
2372 | /// Build the lowest possible value of V, taking into account V's | |||
2373 | /// uninitialized bits. | |||
2374 | Value *getLowestPossibleValue(IRBuilder<> &IRB, Value *A, Value *Sa, | |||
2375 | bool isSigned) { | |||
2376 | if (isSigned) { | |||
2377 | // Split shadow into sign bit and other bits. | |||
2378 | Value *SaOtherBits = IRB.CreateLShr(IRB.CreateShl(Sa, 1), 1); | |||
2379 | Value *SaSignBit = IRB.CreateXor(Sa, SaOtherBits); | |||
2380 | // Maximise the undefined shadow bit, minimize other undefined bits. | |||
2381 | return | |||
2382 | IRB.CreateOr(IRB.CreateAnd(A, IRB.CreateNot(SaOtherBits)), SaSignBit); | |||
2383 | } else { | |||
2384 | // Minimize undefined bits. | |||
2385 | return IRB.CreateAnd(A, IRB.CreateNot(Sa)); | |||
2386 | } | |||
2387 | } | |||
2388 | ||||
2389 | /// Build the highest possible value of V, taking into account V's | |||
2390 | /// uninitialized bits. | |||
2391 | Value *getHighestPossibleValue(IRBuilder<> &IRB, Value *A, Value *Sa, | |||
2392 | bool isSigned) { | |||
2393 | if (isSigned) { | |||
2394 | // Split shadow into sign bit and other bits. | |||
2395 | Value *SaOtherBits = IRB.CreateLShr(IRB.CreateShl(Sa, 1), 1); | |||
2396 | Value *SaSignBit = IRB.CreateXor(Sa, SaOtherBits); | |||
2397 | // Minimise the undefined shadow bit, maximise other undefined bits. | |||
2398 | return | |||
2399 | IRB.CreateOr(IRB.CreateAnd(A, IRB.CreateNot(SaSignBit)), SaOtherBits); | |||
2400 | } else { | |||
2401 | // Maximize undefined bits. | |||
2402 | return IRB.CreateOr(A, Sa); | |||
2403 | } | |||
2404 | } | |||
2405 | ||||
2406 | /// Instrument relational comparisons. | |||
2407 | /// | |||
2408 | /// This function does exact shadow propagation for all relational | |||
2409 | /// comparisons of integers, pointers and vectors of those. | |||
2410 | /// FIXME: output seems suboptimal when one of the operands is a constant | |||
2411 | void handleRelationalComparisonExact(ICmpInst &I) { | |||
2412 | IRBuilder<> IRB(&I); | |||
2413 | Value *A = I.getOperand(0); | |||
2414 | Value *B = I.getOperand(1); | |||
2415 | Value *Sa = getShadow(A); | |||
2416 | Value *Sb = getShadow(B); | |||
2417 | ||||
2418 | // Get rid of pointers and vectors of pointers. | |||
2419 | // For ints (and vectors of ints), types of A and Sa match, | |||
2420 | // and this is a no-op. | |||
2421 | A = IRB.CreatePointerCast(A, Sa->getType()); | |||
2422 | B = IRB.CreatePointerCast(B, Sb->getType()); | |||
2423 | ||||
2424 | // Let [a0, a1] be the interval of possible values of A, taking into account | |||
2425 | // its undefined bits. Let [b0, b1] be the interval of possible values of B. | |||
2426 | // Then (A cmp B) is defined iff (a0 cmp b1) == (a1 cmp b0). | |||
2427 | bool IsSigned = I.isSigned(); | |||
2428 | Value *S1 = IRB.CreateICmp(I.getPredicate(), | |||
2429 | getLowestPossibleValue(IRB, A, Sa, IsSigned), | |||
2430 | getHighestPossibleValue(IRB, B, Sb, IsSigned)); | |||
2431 | Value *S2 = IRB.CreateICmp(I.getPredicate(), | |||
2432 | getHighestPossibleValue(IRB, A, Sa, IsSigned), | |||
2433 | getLowestPossibleValue(IRB, B, Sb, IsSigned)); | |||
2434 | Value *Si = IRB.CreateXor(S1, S2); | |||
2435 | setShadow(&I, Si); | |||
2436 | setOriginForNaryOp(I); | |||
2437 | } | |||
2438 | ||||
2439 | /// Instrument signed relational comparisons. | |||
2440 | /// | |||
2441 | /// Handle sign bit tests: x<0, x>=0, x<=-1, x>-1 by propagating the highest | |||
2442 | /// bit of the shadow. Everything else is delegated to handleShadowOr(). | |||
2443 | void handleSignedRelationalComparison(ICmpInst &I) { | |||
2444 | Constant *constOp; | |||
2445 | Value *op = nullptr; | |||
2446 | CmpInst::Predicate pre; | |||
2447 | if ((constOp = dyn_cast<Constant>(I.getOperand(1)))) { | |||
2448 | op = I.getOperand(0); | |||
2449 | pre = I.getPredicate(); | |||
2450 | } else if ((constOp = dyn_cast<Constant>(I.getOperand(0)))) { | |||
2451 | op = I.getOperand(1); | |||
2452 | pre = I.getSwappedPredicate(); | |||
2453 | } else { | |||
2454 | handleShadowOr(I); | |||
2455 | return; | |||
2456 | } | |||
2457 | ||||
2458 | if ((constOp->isNullValue() && | |||
2459 | (pre == CmpInst::ICMP_SLT || pre == CmpInst::ICMP_SGE)) || | |||
2460 | (constOp->isAllOnesValue() && | |||
2461 | (pre == CmpInst::ICMP_SGT || pre == CmpInst::ICMP_SLE))) { | |||
2462 | IRBuilder<> IRB(&I); | |||
2463 | Value *Shadow = IRB.CreateICmpSLT(getShadow(op), getCleanShadow(op), | |||
2464 | "_msprop_icmp_s"); | |||
2465 | setShadow(&I, Shadow); | |||
2466 | setOrigin(&I, getOrigin(op)); | |||
2467 | } else { | |||
2468 | handleShadowOr(I); | |||
2469 | } | |||
2470 | } | |||
2471 | ||||
2472 | void visitICmpInst(ICmpInst &I) { | |||
2473 | if (!ClHandleICmp) { | |||
| ||||
2474 | handleShadowOr(I); | |||
2475 | return; | |||
2476 | } | |||
2477 | if (I.isEquality()) { | |||
2478 | handleEqualityComparison(I); | |||
2479 | return; | |||
2480 | } | |||
2481 | ||||
2482 | assert(I.isRelational())((void)0); | |||
2483 | if (ClHandleICmpExact) { | |||
2484 | handleRelationalComparisonExact(I); | |||
2485 | return; | |||
2486 | } | |||
2487 | if (I.isSigned()) { | |||
2488 | handleSignedRelationalComparison(I); | |||
2489 | return; | |||
2490 | } | |||
2491 | ||||
2492 | assert(I.isUnsigned())((void)0); | |||
2493 | if ((isa<Constant>(I.getOperand(0)) || isa<Constant>(I.getOperand(1)))) { | |||
2494 | handleRelationalComparisonExact(I); | |||
2495 | return; | |||
2496 | } | |||
2497 | ||||
2498 | handleShadowOr(I); | |||
2499 | } | |||
2500 | ||||
2501 | void visitFCmpInst(FCmpInst &I) { | |||
2502 | handleShadowOr(I); | |||
2503 | } | |||
2504 | ||||
2505 | void handleShift(BinaryOperator &I) { | |||
2506 | IRBuilder<> IRB(&I); | |||
2507 | // If any of the S2 bits are poisoned, the whole thing is poisoned. | |||
2508 | // Otherwise perform the same shift on S1. | |||
2509 | Value *S1 = getShadow(&I, 0); | |||
2510 | Value *S2 = getShadow(&I, 1); | |||
2511 | Value *S2Conv = IRB.CreateSExt(IRB.CreateICmpNE(S2, getCleanShadow(S2)), | |||
2512 | S2->getType()); | |||
2513 | Value *V2 = I.getOperand(1); | |||
2514 | Value *Shift = IRB.CreateBinOp(I.getOpcode(), S1, V2); | |||
2515 | setShadow(&I, IRB.CreateOr(Shift, S2Conv)); | |||
2516 | setOriginForNaryOp(I); | |||
2517 | } | |||
2518 | ||||
2519 | void visitShl(BinaryOperator &I) { handleShift(I); } | |||
2520 | void visitAShr(BinaryOperator &I) { handleShift(I); } | |||
2521 | void visitLShr(BinaryOperator &I) { handleShift(I); } | |||
2522 | ||||
2523 | void handleFunnelShift(IntrinsicInst &I) { | |||
2524 | IRBuilder<> IRB(&I); | |||
2525 | // If any of the S2 bits are poisoned, the whole thing is poisoned. | |||
2526 | // Otherwise perform the same shift on S0 and S1. | |||
2527 | Value *S0 = getShadow(&I, 0); | |||
2528 | Value *S1 = getShadow(&I, 1); | |||
2529 | Value *S2 = getShadow(&I, 2); | |||
2530 | Value *S2Conv = | |||
2531 | IRB.CreateSExt(IRB.CreateICmpNE(S2, getCleanShadow(S2)), S2->getType()); | |||
2532 | Value *V2 = I.getOperand(2); | |||
2533 | Function *Intrin = Intrinsic::getDeclaration( | |||
2534 | I.getModule(), I.getIntrinsicID(), S2Conv->getType()); | |||
2535 | Value *Shift = IRB.CreateCall(Intrin, {S0, S1, V2}); | |||
2536 | setShadow(&I, IRB.CreateOr(Shift, S2Conv)); | |||
2537 | setOriginForNaryOp(I); | |||
2538 | } | |||
2539 | ||||
2540 | /// Instrument llvm.memmove | |||
2541 | /// | |||
2542 | /// At this point we don't know if llvm.memmove will be inlined or not. | |||
2543 | /// If we don't instrument it and it gets inlined, | |||
2544 | /// our interceptor will not kick in and we will lose the memmove. | |||
2545 | /// If we instrument the call here, but it does not get inlined, | |||
2546 | /// we will memove the shadow twice: which is bad in case | |||
2547 | /// of overlapping regions. So, we simply lower the intrinsic to a call. | |||
2548 | /// | |||
2549 | /// Similar situation exists for memcpy and memset. | |||
2550 | void visitMemMoveInst(MemMoveInst &I) { | |||
2551 | IRBuilder<> IRB(&I); | |||
2552 | IRB.CreateCall( | |||
2553 | MS.MemmoveFn, | |||
2554 | {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()), | |||
2555 | IRB.CreatePointerCast(I.getArgOperand(1), IRB.getInt8PtrTy()), | |||
2556 | IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)}); | |||
2557 | I.eraseFromParent(); | |||
2558 | } | |||
2559 | ||||
2560 | // Similar to memmove: avoid copying shadow twice. | |||
2561 | // This is somewhat unfortunate as it may slowdown small constant memcpys. | |||
2562 | // FIXME: consider doing manual inline for small constant sizes and proper | |||
2563 | // alignment. | |||
2564 | void visitMemCpyInst(MemCpyInst &I) { | |||
2565 | IRBuilder<> IRB(&I); | |||
2566 | IRB.CreateCall( | |||
2567 | MS.MemcpyFn, | |||
2568 | {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()), | |||
2569 | IRB.CreatePointerCast(I.getArgOperand(1), IRB.getInt8PtrTy()), | |||
2570 | IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)}); | |||
2571 | I.eraseFromParent(); | |||
2572 | } | |||
2573 | ||||
2574 | // Same as memcpy. | |||
2575 | void visitMemSetInst(MemSetInst &I) { | |||
2576 | IRBuilder<> IRB(&I); | |||
2577 | IRB.CreateCall( | |||
2578 | MS.MemsetFn, | |||
2579 | {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()), | |||
2580 | IRB.CreateIntCast(I.getArgOperand(1), IRB.getInt32Ty(), false), | |||
2581 | IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)}); | |||
2582 | I.eraseFromParent(); | |||
2583 | } | |||
2584 | ||||
2585 | void visitVAStartInst(VAStartInst &I) { | |||
2586 | VAHelper->visitVAStartInst(I); | |||
2587 | } | |||
2588 | ||||
2589 | void visitVACopyInst(VACopyInst &I) { | |||
2590 | VAHelper->visitVACopyInst(I); | |||
2591 | } | |||
2592 | ||||
2593 | /// Handle vector store-like intrinsics. | |||
2594 | /// | |||
2595 | /// Instrument intrinsics that look like a simple SIMD store: writes memory, | |||
2596 | /// has 1 pointer argument and 1 vector argument, returns void. | |||
2597 | bool handleVectorStoreIntrinsic(IntrinsicInst &I) { | |||
2598 | IRBuilder<> IRB(&I); | |||
2599 | Value* Addr = I.getArgOperand(0); | |||
2600 | Value *Shadow = getShadow(&I, 1); | |||
2601 | Value *ShadowPtr, *OriginPtr; | |||
2602 | ||||
2603 | // We don't know the pointer alignment (could be unaligned SSE store!). | |||
2604 | // Have to assume to worst case. | |||
2605 | std::tie(ShadowPtr, OriginPtr) = getShadowOriginPtr( | |||
2606 | Addr, IRB, Shadow->getType(), Align(1), /*isStore*/ true); | |||
2607 | IRB.CreateAlignedStore(Shadow, ShadowPtr, Align(1)); | |||
2608 | ||||
2609 | if (ClCheckAccessAddress) | |||
2610 | insertShadowCheck(Addr, &I); | |||
2611 | ||||
2612 | // FIXME: factor out common code from materializeStores | |||
2613 | if (MS.TrackOrigins) IRB.CreateStore(getOrigin(&I, 1), OriginPtr); | |||
2614 | return true; | |||
2615 | } | |||
2616 | ||||
2617 | /// Handle vector load-like intrinsics. | |||
2618 | /// | |||
2619 | /// Instrument intrinsics that look like a simple SIMD load: reads memory, | |||
2620 | /// has 1 pointer argument, returns a vector. | |||
2621 | bool handleVectorLoadIntrinsic(IntrinsicInst &I) { | |||
2622 | IRBuilder<> IRB(&I); | |||
2623 | Value *Addr = I.getArgOperand(0); | |||
2624 | ||||
2625 | Type *ShadowTy = getShadowTy(&I); | |||
2626 | Value *ShadowPtr = nullptr, *OriginPtr = nullptr; | |||
2627 | if (PropagateShadow) { | |||
2628 | // We don't know the pointer alignment (could be unaligned SSE load!). | |||
2629 | // Have to assume to worst case. | |||
2630 | const Align Alignment = Align(1); | |||
2631 | std::tie(ShadowPtr, OriginPtr) = | |||
2632 | getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ false); | |||
2633 | setShadow(&I, | |||
2634 | IRB.CreateAlignedLoad(ShadowTy, ShadowPtr, Alignment, "_msld")); | |||
2635 | } else { | |||
2636 | setShadow(&I, getCleanShadow(&I)); | |||
2637 | } | |||
2638 | ||||
2639 | if (ClCheckAccessAddress) | |||
2640 | insertShadowCheck(Addr, &I); | |||
2641 | ||||
2642 | if (MS.TrackOrigins) { | |||
2643 | if (PropagateShadow) | |||
2644 | setOrigin(&I, IRB.CreateLoad(MS.OriginTy, OriginPtr)); | |||
2645 | else | |||
2646 | setOrigin(&I, getCleanOrigin()); | |||
2647 | } | |||
2648 | return true; | |||
2649 | } | |||
2650 | ||||
2651 | /// Handle (SIMD arithmetic)-like intrinsics. | |||
2652 | /// | |||
2653 | /// Instrument intrinsics with any number of arguments of the same type, | |||
2654 | /// equal to the return type. The type should be simple (no aggregates or | |||
2655 | /// pointers; vectors are fine). | |||
2656 | /// Caller guarantees that this intrinsic does not access memory. | |||
2657 | bool maybeHandleSimpleNomemIntrinsic(IntrinsicInst &I) { | |||
2658 | Type *RetTy = I.getType(); | |||
2659 | if (!(RetTy->isIntOrIntVectorTy() || | |||
2660 | RetTy->isFPOrFPVectorTy() || | |||
2661 | RetTy->isX86_MMXTy())) | |||
2662 | return false; | |||
2663 | ||||
2664 | unsigned NumArgOperands = I.getNumArgOperands(); | |||
2665 | for (unsigned i = 0; i < NumArgOperands; ++i) { | |||
2666 | Type *Ty = I.getArgOperand(i)->getType(); | |||
2667 | if (Ty != RetTy) | |||
2668 | return false; | |||
2669 | } | |||
2670 | ||||
2671 | IRBuilder<> IRB(&I); | |||
2672 | ShadowAndOriginCombiner SC(this, IRB); | |||
2673 | for (unsigned i = 0; i < NumArgOperands; ++i) | |||
2674 | SC.Add(I.getArgOperand(i)); | |||
2675 | SC.Done(&I); | |||
2676 | ||||
2677 | return true; | |||
2678 | } | |||
2679 | ||||
2680 | /// Heuristically instrument unknown intrinsics. | |||
2681 | /// | |||
2682 | /// The main purpose of this code is to do something reasonable with all | |||
2683 | /// random intrinsics we might encounter, most importantly - SIMD intrinsics. | |||
2684 | /// We recognize several classes of intrinsics by their argument types and | |||
2685 | /// ModRefBehaviour and apply special instrumentation when we are reasonably | |||
2686 | /// sure that we know what the intrinsic does. | |||
2687 | /// | |||
2688 | /// We special-case intrinsics where this approach fails. See llvm.bswap | |||
2689 | /// handling as an example of that. | |||
2690 | bool handleUnknownIntrinsic(IntrinsicInst &I) { | |||
2691 | unsigned NumArgOperands = I.getNumArgOperands(); | |||
2692 | if (NumArgOperands == 0) | |||
2693 | return false; | |||
2694 | ||||
2695 | if (NumArgOperands == 2 && | |||
2696 | I.getArgOperand(0)->getType()->isPointerTy() && | |||
2697 | I.getArgOperand(1)->getType()->isVectorTy() && | |||
2698 | I.getType()->isVoidTy() && | |||
2699 | !I.onlyReadsMemory()) { | |||
2700 | // This looks like a vector store. | |||
2701 | return handleVectorStoreIntrinsic(I); | |||
2702 | } | |||
2703 | ||||
2704 | if (NumArgOperands == 1 && | |||
2705 | I.getArgOperand(0)->getType()->isPointerTy() && | |||
2706 | I.getType()->isVectorTy() && | |||
2707 | I.onlyReadsMemory()) { | |||
2708 | // This looks like a vector load. | |||
2709 | return handleVectorLoadIntrinsic(I); | |||
2710 | } | |||
2711 | ||||
2712 | if (I.doesNotAccessMemory()) | |||
2713 | if (maybeHandleSimpleNomemIntrinsic(I)) | |||
2714 | return true; | |||
2715 | ||||
2716 | // FIXME: detect and handle SSE maskstore/maskload | |||
2717 | return false; | |||
2718 | } | |||
2719 | ||||
2720 | void handleInvariantGroup(IntrinsicInst &I) { | |||
2721 | setShadow(&I, getShadow(&I, 0)); | |||
2722 | setOrigin(&I, getOrigin(&I, 0)); | |||
2723 | } | |||
2724 | ||||
2725 | void handleLifetimeStart(IntrinsicInst &I) { | |||
2726 | if (!PoisonStack) | |||
2727 | return; | |||
2728 | AllocaInst *AI = llvm::findAllocaForValue(I.getArgOperand(1)); | |||
2729 | if (!AI) | |||
2730 | InstrumentLifetimeStart = false; | |||
2731 | LifetimeStartList.push_back(std::make_pair(&I, AI)); | |||
2732 | } | |||
2733 | ||||
2734 | void handleBswap(IntrinsicInst &I) { | |||
2735 | IRBuilder<> IRB(&I); | |||
2736 | Value *Op = I.getArgOperand(0); | |||
2737 | Type *OpType = Op->getType(); | |||
2738 | Function *BswapFunc = Intrinsic::getDeclaration( | |||
2739 | F.getParent(), Intrinsic::bswap, makeArrayRef(&OpType, 1)); | |||
2740 | setShadow(&I, IRB.CreateCall(BswapFunc, getShadow(Op))); | |||
2741 | setOrigin(&I, getOrigin(Op)); | |||
2742 | } | |||
2743 | ||||
2744 | // Instrument vector convert intrinsic. | |||
2745 | // | |||
2746 | // This function instruments intrinsics like cvtsi2ss: | |||
2747 | // %Out = int_xxx_cvtyyy(%ConvertOp) | |||
2748 | // or | |||
2749 | // %Out = int_xxx_cvtyyy(%CopyOp, %ConvertOp) | |||
2750 | // Intrinsic converts \p NumUsedElements elements of \p ConvertOp to the same | |||
2751 | // number \p Out elements, and (if has 2 arguments) copies the rest of the | |||
2752 | // elements from \p CopyOp. | |||
2753 | // In most cases conversion involves floating-point value which may trigger a | |||
2754 | // hardware exception when not fully initialized. For this reason we require | |||
2755 | // \p ConvertOp[0:NumUsedElements] to be fully initialized and trap otherwise. | |||
2756 | // We copy the shadow of \p CopyOp[NumUsedElements:] to \p | |||
2757 | // Out[NumUsedElements:]. This means that intrinsics without \p CopyOp always | |||
2758 | // return a fully initialized value. | |||
2759 | void handleVectorConvertIntrinsic(IntrinsicInst &I, int NumUsedElements, | |||
2760 | bool HasRoundingMode = false) { | |||
2761 | IRBuilder<> IRB(&I); | |||
2762 | Value *CopyOp, *ConvertOp; | |||
2763 | ||||
2764 | assert((!HasRoundingMode ||((void)0) | |||
2765 | isa<ConstantInt>(I.getArgOperand(I.getNumArgOperands() - 1))) &&((void)0) | |||
2766 | "Invalid rounding mode")((void)0); | |||
2767 | ||||
2768 | switch (I.getNumArgOperands() - HasRoundingMode) { | |||
2769 | case 2: | |||
2770 | CopyOp = I.getArgOperand(0); | |||
2771 | ConvertOp = I.getArgOperand(1); | |||
2772 | break; | |||
2773 | case 1: | |||
2774 | ConvertOp = I.getArgOperand(0); | |||
2775 | CopyOp = nullptr; | |||
2776 | break; | |||
2777 | default: | |||
2778 | llvm_unreachable("Cvt intrinsic with unsupported number of arguments.")__builtin_unreachable(); | |||
2779 | } | |||
2780 | ||||
2781 | // The first *NumUsedElements* elements of ConvertOp are converted to the | |||
2782 | // same number of output elements. The rest of the output is copied from | |||
2783 | // CopyOp, or (if not available) filled with zeroes. | |||
2784 | // Combine shadow for elements of ConvertOp that are used in this operation, | |||
2785 | // and insert a check. | |||
2786 | // FIXME: consider propagating shadow of ConvertOp, at least in the case of | |||
2787 | // int->any conversion. | |||
2788 | Value *ConvertShadow = getShadow(ConvertOp); | |||
2789 | Value *AggShadow = nullptr; | |||
2790 | if (ConvertOp->getType()->isVectorTy()) { | |||
2791 | AggShadow = IRB.CreateExtractElement( | |||
2792 | ConvertShadow, ConstantInt::get(IRB.getInt32Ty(), 0)); | |||
2793 | for (int i = 1; i < NumUsedElements; ++i) { | |||
2794 | Value *MoreShadow = IRB.CreateExtractElement( | |||
2795 | ConvertShadow, ConstantInt::get(IRB.getInt32Ty(), i)); | |||
2796 | AggShadow = IRB.CreateOr(AggShadow, MoreShadow); | |||
2797 | } | |||
2798 | } else { | |||
2799 | AggShadow = ConvertShadow; | |||
2800 | } | |||
2801 | assert(AggShadow->getType()->isIntegerTy())((void)0); | |||
2802 | insertShadowCheck(AggShadow, getOrigin(ConvertOp), &I); | |||
2803 | ||||
2804 | // Build result shadow by zero-filling parts of CopyOp shadow that come from | |||
2805 | // ConvertOp. | |||
2806 | if (CopyOp) { | |||
2807 | assert(CopyOp->getType() == I.getType())((void)0); | |||
2808 | assert(CopyOp->getType()->isVectorTy())((void)0); | |||
2809 | Value *ResultShadow = getShadow(CopyOp); | |||
2810 | Type *EltTy = cast<VectorType>(ResultShadow->getType())->getElementType(); | |||
2811 | for (int i = 0; i < NumUsedElements; ++i) { | |||
2812 | ResultShadow = IRB.CreateInsertElement( | |||
2813 | ResultShadow, ConstantInt::getNullValue(EltTy), | |||
2814 | ConstantInt::get(IRB.getInt32Ty(), i)); | |||
2815 | } | |||
2816 | setShadow(&I, ResultShadow); | |||
2817 | setOrigin(&I, getOrigin(CopyOp)); | |||
2818 | } else { | |||
2819 | setShadow(&I, getCleanShadow(&I)); | |||
2820 | setOrigin(&I, getCleanOrigin()); | |||
2821 | } | |||
2822 | } | |||
2823 | ||||
2824 | // Given a scalar or vector, extract lower 64 bits (or less), and return all | |||
2825 | // zeroes if it is zero, and all ones otherwise. | |||
2826 | Value *Lower64ShadowExtend(IRBuilder<> &IRB, Value *S, Type *T) { | |||
2827 | if (S->getType()->isVectorTy()) | |||
2828 | S = CreateShadowCast(IRB, S, IRB.getInt64Ty(), /* Signed */ true); | |||
2829 | assert(S->getType()->getPrimitiveSizeInBits() <= 64)((void)0); | |||
2830 | Value *S2 = IRB.CreateICmpNE(S, getCleanShadow(S)); | |||
2831 | return CreateShadowCast(IRB, S2, T, /* Signed */ true); | |||
2832 | } | |||
2833 | ||||
2834 | // Given a vector, extract its first element, and return all | |||
2835 | // zeroes if it is zero, and all ones otherwise. | |||
2836 | Value *LowerElementShadowExtend(IRBuilder<> &IRB, Value *S, Type *T) { | |||
2837 | Value *S1 = IRB.CreateExtractElement(S, (uint64_t)0); | |||
2838 | Value *S2 = IRB.CreateICmpNE(S1, getCleanShadow(S1)); | |||
2839 | return CreateShadowCast(IRB, S2, T, /* Signed */ true); | |||
2840 | } | |||
2841 | ||||
2842 | Value *VariableShadowExtend(IRBuilder<> &IRB, Value *S) { | |||
2843 | Type *T = S->getType(); | |||
2844 | assert(T->isVectorTy())((void)0); | |||
2845 | Value *S2 = IRB.CreateICmpNE(S, getCleanShadow(S)); | |||
2846 | return IRB.CreateSExt(S2, T); | |||
2847 | } | |||
2848 | ||||
2849 | // Instrument vector shift intrinsic. | |||
2850 | // | |||
2851 | // This function instruments intrinsics like int_x86_avx2_psll_w. | |||
2852 | // Intrinsic shifts %In by %ShiftSize bits. | |||
2853 | // %ShiftSize may be a vector. In that case the lower 64 bits determine shift | |||
2854 | // size, and the rest is ignored. Behavior is defined even if shift size is | |||
2855 | // greater than register (or field) width. | |||
2856 | void handleVectorShiftIntrinsic(IntrinsicInst &I, bool Variable) { | |||
2857 | assert(I.getNumArgOperands() == 2)((void)0); | |||
2858 | IRBuilder<> IRB(&I); | |||
2859 | // If any of the S2 bits are poisoned, the whole thing is poisoned. | |||
2860 | // Otherwise perform the same shift on S1. | |||
2861 | Value *S1 = getShadow(&I, 0); | |||
2862 | Value *S2 = getShadow(&I, 1); | |||
2863 | Value *S2Conv = Variable ? VariableShadowExtend(IRB, S2) | |||
2864 | : Lower64ShadowExtend(IRB, S2, getShadowTy(&I)); | |||
2865 | Value *V1 = I.getOperand(0); | |||
2866 | Value *V2 = I.getOperand(1); | |||
2867 | Value *Shift = IRB.CreateCall(I.getFunctionType(), I.getCalledOperand(), | |||
2868 | {IRB.CreateBitCast(S1, V1->getType()), V2}); | |||
2869 | Shift = IRB.CreateBitCast(Shift, getShadowTy(&I)); | |||
2870 | setShadow(&I, IRB.CreateOr(Shift, S2Conv)); | |||
2871 | setOriginForNaryOp(I); | |||
2872 | } | |||
2873 | ||||
2874 | // Get an X86_MMX-sized vector type. | |||
2875 | Type *getMMXVectorTy(unsigned EltSizeInBits) { | |||
2876 | const unsigned X86_MMXSizeInBits = 64; | |||
2877 | assert(EltSizeInBits != 0 && (X86_MMXSizeInBits % EltSizeInBits) == 0 &&((void)0) | |||
2878 | "Illegal MMX vector element size")((void)0); | |||
2879 | return FixedVectorType::get(IntegerType::get(*MS.C, EltSizeInBits), | |||
2880 | X86_MMXSizeInBits / EltSizeInBits); | |||
2881 | } | |||
2882 | ||||
2883 | // Returns a signed counterpart for an (un)signed-saturate-and-pack | |||
2884 | // intrinsic. | |||
2885 | Intrinsic::ID getSignedPackIntrinsic(Intrinsic::ID id) { | |||
2886 | switch (id) { | |||
2887 | case Intrinsic::x86_sse2_packsswb_128: | |||
2888 | case Intrinsic::x86_sse2_packuswb_128: | |||
2889 | return Intrinsic::x86_sse2_packsswb_128; | |||
2890 | ||||
2891 | case Intrinsic::x86_sse2_packssdw_128: | |||
2892 | case Intrinsic::x86_sse41_packusdw: | |||
2893 | return Intrinsic::x86_sse2_packssdw_128; | |||
2894 | ||||
2895 | case Intrinsic::x86_avx2_packsswb: | |||
2896 | case Intrinsic::x86_avx2_packuswb: | |||
2897 | return Intrinsic::x86_avx2_packsswb; | |||
2898 | ||||
2899 | case Intrinsic::x86_avx2_packssdw: | |||
2900 | case Intrinsic::x86_avx2_packusdw: | |||
2901 | return Intrinsic::x86_avx2_packssdw; | |||
2902 | ||||
2903 | case Intrinsic::x86_mmx_packsswb: | |||
2904 | case Intrinsic::x86_mmx_packuswb: | |||
2905 | return Intrinsic::x86_mmx_packsswb; | |||
2906 | ||||
2907 | case Intrinsic::x86_mmx_packssdw: | |||
2908 | return Intrinsic::x86_mmx_packssdw; | |||
2909 | default: | |||
2910 | llvm_unreachable("unexpected intrinsic id")__builtin_unreachable(); | |||
2911 | } | |||
2912 | } | |||
2913 | ||||
2914 | // Instrument vector pack intrinsic. | |||
2915 | // | |||
2916 | // This function instruments intrinsics like x86_mmx_packsswb, that | |||
2917 | // packs elements of 2 input vectors into half as many bits with saturation. | |||
2918 | // Shadow is propagated with the signed variant of the same intrinsic applied | |||
2919 | // to sext(Sa != zeroinitializer), sext(Sb != zeroinitializer). | |||
2920 | // EltSizeInBits is used only for x86mmx arguments. | |||
2921 | void handleVectorPackIntrinsic(IntrinsicInst &I, unsigned EltSizeInBits = 0) { | |||
2922 | assert(I.getNumArgOperands() == 2)((void)0); | |||
2923 | bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy(); | |||
2924 | IRBuilder<> IRB(&I); | |||
2925 | Value *S1 = getShadow(&I, 0); | |||
2926 | Value *S2 = getShadow(&I, 1); | |||
2927 | assert(isX86_MMX || S1->getType()->isVectorTy())((void)0); | |||
2928 | ||||
2929 | // SExt and ICmpNE below must apply to individual elements of input vectors. | |||
2930 | // In case of x86mmx arguments, cast them to appropriate vector types and | |||
2931 | // back. | |||
2932 | Type *T = isX86_MMX ? getMMXVectorTy(EltSizeInBits) : S1->getType(); | |||
2933 | if (isX86_MMX) { | |||
2934 | S1 = IRB.CreateBitCast(S1, T); | |||
2935 | S2 = IRB.CreateBitCast(S2, T); | |||
2936 | } | |||
2937 | Value *S1_ext = IRB.CreateSExt( | |||
2938 | IRB.CreateICmpNE(S1, Constant::getNullValue(T)), T); | |||
2939 | Value *S2_ext = IRB.CreateSExt( | |||
2940 | IRB.CreateICmpNE(S2, Constant::getNullValue(T)), T); | |||
2941 | if (isX86_MMX) { | |||
2942 | Type *X86_MMXTy = Type::getX86_MMXTy(*MS.C); | |||
2943 | S1_ext = IRB.CreateBitCast(S1_ext, X86_MMXTy); | |||
2944 | S2_ext = IRB.CreateBitCast(S2_ext, X86_MMXTy); | |||
2945 | } | |||
2946 | ||||
2947 | Function *ShadowFn = Intrinsic::getDeclaration( | |||
2948 | F.getParent(), getSignedPackIntrinsic(I.getIntrinsicID())); | |||
2949 | ||||
2950 | Value *S = | |||
2951 | IRB.CreateCall(ShadowFn, {S1_ext, S2_ext}, "_msprop_vector_pack"); | |||
2952 | if (isX86_MMX) S = IRB.CreateBitCast(S, getShadowTy(&I)); | |||
2953 | setShadow(&I, S); | |||
2954 | setOriginForNaryOp(I); | |||
2955 | } | |||
2956 | ||||
2957 | // Instrument sum-of-absolute-differences intrinsic. | |||
2958 | void handleVectorSadIntrinsic(IntrinsicInst &I) { | |||
2959 | const unsigned SignificantBitsPerResultElement = 16; | |||
2960 | bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy(); | |||
2961 | Type *ResTy = isX86_MMX ? IntegerType::get(*MS.C, 64) : I.getType(); | |||
2962 | unsigned ZeroBitsPerResultElement = | |||
2963 | ResTy->getScalarSizeInBits() - SignificantBitsPerResultElement; | |||
2964 | ||||
2965 | IRBuilder<> IRB(&I); | |||
2966 | Value *S = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1)); | |||
2967 | S = IRB.CreateBitCast(S, ResTy); | |||
2968 | S = IRB.CreateSExt(IRB.CreateICmpNE(S, Constant::getNullValue(ResTy)), | |||
2969 | ResTy); | |||
2970 | S = IRB.CreateLShr(S, ZeroBitsPerResultElement); | |||
2971 | S = IRB.CreateBitCast(S, getShadowTy(&I)); | |||
2972 | setShadow(&I, S); | |||
2973 | setOriginForNaryOp(I); | |||
2974 | } | |||
2975 | ||||
2976 | // Instrument multiply-add intrinsic. | |||
2977 | void handleVectorPmaddIntrinsic(IntrinsicInst &I, | |||
2978 | unsigned EltSizeInBits = 0) { | |||
2979 | bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy(); | |||
2980 | Type *ResTy = isX86_MMX ? getMMXVectorTy(EltSizeInBits * 2) : I.getType(); | |||
2981 | IRBuilder<> IRB(&I); | |||
2982 | Value *S = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1)); | |||
2983 | S = IRB.CreateBitCast(S, ResTy); | |||
2984 | S = IRB.CreateSExt(IRB.CreateICmpNE(S, Constant::getNullValue(ResTy)), | |||
2985 | ResTy); | |||
2986 | S = IRB.CreateBitCast(S, getShadowTy(&I)); | |||
2987 | setShadow(&I, S); | |||
2988 | setOriginForNaryOp(I); | |||
2989 | } | |||
2990 | ||||
2991 | // Instrument compare-packed intrinsic. | |||
2992 | // Basically, an or followed by sext(icmp ne 0) to end up with all-zeros or | |||
2993 | // all-ones shadow. | |||
2994 | void handleVectorComparePackedIntrinsic(IntrinsicInst &I) { | |||
2995 | IRBuilder<> IRB(&I); | |||
2996 | Type *ResTy = getShadowTy(&I); | |||
2997 | Value *S0 = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1)); | |||
2998 | Value *S = IRB.CreateSExt( | |||
2999 | IRB.CreateICmpNE(S0, Constant::getNullValue(ResTy)), ResTy); | |||
3000 | setShadow(&I, S); | |||
3001 | setOriginForNaryOp(I); | |||
3002 | } | |||
3003 | ||||
3004 | // Instrument compare-scalar intrinsic. | |||
3005 | // This handles both cmp* intrinsics which return the result in the first | |||
3006 | // element of a vector, and comi* which return the result as i32. | |||
3007 | void handleVectorCompareScalarIntrinsic(IntrinsicInst &I) { | |||
3008 | IRBuilder<> IRB(&I); | |||
3009 | Value *S0 = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1)); | |||
3010 | Value *S = LowerElementShadowExtend(IRB, S0, getShadowTy(&I)); | |||
3011 | setShadow(&I, S); | |||
3012 | setOriginForNaryOp(I); | |||
3013 | } | |||
3014 | ||||
3015 | // Instrument generic vector reduction intrinsics | |||
3016 | // by ORing together all their fields. | |||
3017 | void handleVectorReduceIntrinsic(IntrinsicInst &I) { | |||
3018 | IRBuilder<> IRB(&I); | |||
3019 | Value *S = IRB.CreateOrReduce(getShadow(&I, 0)); | |||
3020 | setShadow(&I, S); | |||
3021 | setOrigin(&I, getOrigin(&I, 0)); | |||
3022 | } | |||
3023 | ||||
3024 | // Instrument vector.reduce.or intrinsic. | |||
3025 | // Valid (non-poisoned) set bits in the operand pull low the | |||
3026 | // corresponding shadow bits. | |||
3027 | void handleVectorReduceOrIntrinsic(IntrinsicInst &I) { | |||
3028 | IRBuilder<> IRB(&I); | |||
3029 | Value *OperandShadow = getShadow(&I, 0); | |||
3030 | Value *OperandUnsetBits = IRB.CreateNot(I.getOperand(0)); | |||
3031 | Value *OperandUnsetOrPoison = IRB.CreateOr(OperandUnsetBits, OperandShadow); | |||
3032 | // Bit N is clean if any field's bit N is 1 and unpoison | |||
3033 | Value *OutShadowMask = IRB.CreateAndReduce(OperandUnsetOrPoison); | |||
3034 | // Otherwise, it is clean if every field's bit N is unpoison | |||
3035 | Value *OrShadow = IRB.CreateOrReduce(OperandShadow); | |||
3036 | Value *S = IRB.CreateAnd(OutShadowMask, OrShadow); | |||
3037 | ||||
3038 | setShadow(&I, S); | |||
3039 | setOrigin(&I, getOrigin(&I, 0)); | |||
3040 | } | |||
3041 | ||||
3042 | // Instrument vector.reduce.and intrinsic. | |||
3043 | // Valid (non-poisoned) unset bits in the operand pull down the | |||
3044 | // corresponding shadow bits. | |||
3045 | void handleVectorReduceAndIntrinsic(IntrinsicInst &I) { | |||
3046 | IRBuilder<> IRB(&I); | |||
3047 | Value *OperandShadow = getShadow(&I, 0); | |||
3048 | Value *OperandSetOrPoison = IRB.CreateOr(I.getOperand(0), OperandShadow); | |||
3049 | // Bit N is clean if any field's bit N is 0 and unpoison | |||
3050 | Value *OutShadowMask = IRB.CreateAndReduce(OperandSetOrPoison); | |||
3051 | // Otherwise, it is clean if every field's bit N is unpoison | |||
3052 | Value *OrShadow = IRB.CreateOrReduce(OperandShadow); | |||
3053 | Value *S = IRB.CreateAnd(OutShadowMask, OrShadow); | |||
3054 | ||||
3055 | setShadow(&I, S); | |||
3056 | setOrigin(&I, getOrigin(&I, 0)); | |||
3057 | } | |||
3058 | ||||
3059 | void handleStmxcsr(IntrinsicInst &I) { | |||
3060 | IRBuilder<> IRB(&I); | |||
3061 | Value* Addr = I.getArgOperand(0); | |||
3062 | Type *Ty = IRB.getInt32Ty(); | |||
3063 | Value *ShadowPtr = | |||
3064 | getShadowOriginPtr(Addr, IRB, Ty, Align(1), /*isStore*/ true).first; | |||
3065 | ||||
3066 | IRB.CreateStore(getCleanShadow(Ty), | |||
3067 | IRB.CreatePointerCast(ShadowPtr, Ty->getPointerTo())); | |||
3068 | ||||
3069 | if (ClCheckAccessAddress) | |||
3070 | insertShadowCheck(Addr, &I); | |||
3071 | } | |||
3072 | ||||
3073 | void handleLdmxcsr(IntrinsicInst &I) { | |||
3074 | if (!InsertChecks) return; | |||
3075 | ||||
3076 | IRBuilder<> IRB(&I); | |||
3077 | Value *Addr = I.getArgOperand(0); | |||
3078 | Type *Ty = IRB.getInt32Ty(); | |||
3079 | const Align Alignment = Align(1); | |||
3080 | Value *ShadowPtr, *OriginPtr; | |||
3081 | std::tie(ShadowPtr, OriginPtr) = | |||
3082 | getShadowOriginPtr(Addr, IRB, Ty, Alignment, /*isStore*/ false); | |||
3083 | ||||
3084 | if (ClCheckAccessAddress) | |||
3085 | insertShadowCheck(Addr, &I); | |||
3086 | ||||
3087 | Value *Shadow = IRB.CreateAlignedLoad(Ty, ShadowPtr, Alignment, "_ldmxcsr"); | |||
3088 | Value *Origin = MS.TrackOrigins ? IRB.CreateLoad(MS.OriginTy, OriginPtr) | |||
3089 | : getCleanOrigin(); | |||
3090 | insertShadowCheck(Shadow, Origin, &I); | |||
3091 | } | |||
3092 | ||||
3093 | void handleMaskedStore(IntrinsicInst &I) { | |||
3094 | IRBuilder<> IRB(&I); | |||
3095 | Value *V = I.getArgOperand(0); | |||
3096 | Value *Addr = I.getArgOperand(1); | |||
3097 | const Align Alignment( | |||
3098 | cast<ConstantInt>(I.getArgOperand(2))->getZExtValue()); | |||
3099 | Value *Mask = I.getArgOperand(3); | |||
3100 | Value *Shadow = getShadow(V); | |||
3101 | ||||
3102 | Value *ShadowPtr; | |||
3103 | Value *OriginPtr; | |||
3104 | std::tie(ShadowPtr, OriginPtr) = getShadowOriginPtr( | |||
3105 | Addr, IRB, Shadow->getType(), Alignment, /*isStore*/ true); | |||
3106 | ||||
3107 | if (ClCheckAccessAddress) { | |||
3108 | insertShadowCheck(Addr, &I); | |||
3109 | // Uninitialized mask is kind of like uninitialized address, but not as | |||
3110 | // scary. | |||
3111 | insertShadowCheck(Mask, &I); | |||
3112 | } | |||
3113 | ||||
3114 | IRB.CreateMaskedStore(Shadow, ShadowPtr, Alignment, Mask); | |||
3115 | ||||
3116 | if (MS.TrackOrigins) { | |||
3117 | auto &DL = F.getParent()->getDataLayout(); | |||
3118 | paintOrigin(IRB, getOrigin(V), OriginPtr, | |||
3119 | DL.getTypeStoreSize(Shadow->getType()), | |||
3120 | std::max(Alignment, kMinOriginAlignment)); | |||
3121 | } | |||
3122 | } | |||
3123 | ||||
3124 | bool handleMaskedLoad(IntrinsicInst &I) { | |||
3125 | IRBuilder<> IRB(&I); | |||
3126 | Value *Addr = I.getArgOperand(0); | |||
3127 | const Align Alignment( | |||
3128 | cast<ConstantInt>(I.getArgOperand(1))->getZExtValue()); | |||
3129 | Value *Mask = I.getArgOperand(2); | |||
3130 | Value *PassThru = I.getArgOperand(3); | |||
3131 | ||||
3132 | Type *ShadowTy = getShadowTy(&I); | |||
3133 | Value *ShadowPtr, *OriginPtr; | |||
3134 | if (PropagateShadow) { | |||
3135 | std::tie(ShadowPtr, OriginPtr) = | |||
3136 | getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ false); | |||
3137 | setShadow(&I, IRB.CreateMaskedLoad(ShadowTy, ShadowPtr, Alignment, Mask, | |||
3138 | getShadow(PassThru), "_msmaskedld")); | |||
3139 | } else { | |||
3140 | setShadow(&I, getCleanShadow(&I)); | |||
3141 | } | |||
3142 | ||||
3143 | if (ClCheckAccessAddress) { | |||
3144 | insertShadowCheck(Addr, &I); | |||
3145 | insertShadowCheck(Mask, &I); | |||
3146 | } | |||
3147 | ||||
3148 | if (MS.TrackOrigins) { | |||
3149 | if (PropagateShadow) { | |||
3150 | // Choose between PassThru's and the loaded value's origins. | |||
3151 | Value *MaskedPassThruShadow = IRB.CreateAnd( | |||
3152 | getShadow(PassThru), IRB.CreateSExt(IRB.CreateNeg(Mask), ShadowTy)); | |||
3153 | ||||
3154 | Value *Acc = IRB.CreateExtractElement( | |||
3155 | MaskedPassThruShadow, ConstantInt::get(IRB.getInt32Ty(), 0)); | |||
3156 | for (int i = 1, N = cast<FixedVectorType>(PassThru->getType()) | |||
3157 | ->getNumElements(); | |||
3158 | i < N; ++i) { | |||
3159 | Value *More = IRB.CreateExtractElement( | |||
3160 | MaskedPassThruShadow, ConstantInt::get(IRB.getInt32Ty(), i)); | |||
3161 | Acc = IRB.CreateOr(Acc, More); | |||
3162 | } | |||
3163 | ||||
3164 | Value *Origin = IRB.CreateSelect( | |||
3165 | IRB.CreateICmpNE(Acc, Constant::getNullValue(Acc->getType())), | |||
3166 | getOrigin(PassThru), IRB.CreateLoad(MS.OriginTy, OriginPtr)); | |||
3167 | ||||
3168 | setOrigin(&I, Origin); | |||
3169 | } else { | |||
3170 | setOrigin(&I, getCleanOrigin()); | |||
3171 | } | |||
3172 | } | |||
3173 | return true; | |||
3174 | } | |||
3175 | ||||
3176 | // Instrument BMI / BMI2 intrinsics. | |||
3177 | // All of these intrinsics are Z = I(X, Y) | |||
3178 | // where the types of all operands and the result match, and are either i32 or i64. | |||
3179 | // The following instrumentation happens to work for all of them: | |||
3180 | // Sz = I(Sx, Y) | (sext (Sy != 0)) | |||
3181 | void handleBmiIntrinsic(IntrinsicInst &I) { | |||
3182 | IRBuilder<> IRB(&I); | |||
3183 | Type *ShadowTy = getShadowTy(&I); | |||
3184 | ||||
3185 | // If any bit of the mask operand is poisoned, then the whole thing is. | |||
3186 | Value *SMask = getShadow(&I, 1); | |||
3187 | SMask = IRB.CreateSExt(IRB.CreateICmpNE(SMask, getCleanShadow(ShadowTy)), | |||
3188 | ShadowTy); | |||
3189 | // Apply the same intrinsic to the shadow of the first operand. | |||
3190 | Value *S = IRB.CreateCall(I.getCalledFunction(), | |||
3191 | {getShadow(&I, 0), I.getOperand(1)}); | |||
3192 | S = IRB.CreateOr(SMask, S); | |||
3193 | setShadow(&I, S); | |||
3194 | setOriginForNaryOp(I); | |||
3195 | } | |||
3196 | ||||
3197 | SmallVector<int, 8> getPclmulMask(unsigned Width, bool OddElements) { | |||
3198 | SmallVector<int, 8> Mask; | |||
3199 | for (unsigned X = OddElements ? 1 : 0; X < Width; X += 2) { | |||
3200 | Mask.append(2, X); | |||
3201 | } | |||
3202 | return Mask; | |||
3203 | } | |||
3204 | ||||
3205 | // Instrument pclmul intrinsics. | |||
3206 | // These intrinsics operate either on odd or on even elements of the input | |||
3207 | // vectors, depending on the constant in the 3rd argument, ignoring the rest. | |||
3208 | // Replace the unused elements with copies of the used ones, ex: | |||
3209 | // (0, 1, 2, 3) -> (0, 0, 2, 2) (even case) | |||
3210 | // or | |||
3211 | // (0, 1, 2, 3) -> (1, 1, 3, 3) (odd case) | |||
3212 | // and then apply the usual shadow combining logic. | |||
3213 | void handlePclmulIntrinsic(IntrinsicInst &I) { | |||
3214 | IRBuilder<> IRB(&I); | |||
3215 | unsigned Width = | |||
3216 | cast<FixedVectorType>(I.getArgOperand(0)->getType())->getNumElements(); | |||
3217 | assert(isa<ConstantInt>(I.getArgOperand(2)) &&((void)0) | |||
3218 | "pclmul 3rd operand must be a constant")((void)0); | |||
3219 | unsigned Imm = cast<ConstantInt>(I.getArgOperand(2))->getZExtValue(); | |||
3220 | Value *Shuf0 = IRB.CreateShuffleVector(getShadow(&I, 0), | |||
3221 | getPclmulMask(Width, Imm & 0x01)); | |||
3222 | Value *Shuf1 = IRB.CreateShuffleVector(getShadow(&I, 1), | |||
3223 | getPclmulMask(Width, Imm & 0x10)); | |||
3224 | ShadowAndOriginCombiner SOC(this, IRB); | |||
3225 | SOC.Add(Shuf0, getOrigin(&I, 0)); | |||
3226 | SOC.Add(Shuf1, getOrigin(&I, 1)); | |||
3227 | SOC.Done(&I); | |||
3228 | } | |||
3229 | ||||
3230 | // Instrument _mm_*_sd intrinsics | |||
3231 | void handleUnarySdIntrinsic(IntrinsicInst &I) { | |||
3232 | IRBuilder<> IRB(&I); | |||
3233 | Value *First = getShadow(&I, 0); | |||
3234 | Value *Second = getShadow(&I, 1); | |||
3235 | // High word of first operand, low word of second | |||
3236 | Value *Shadow = | |||
3237 | IRB.CreateShuffleVector(First, Second, llvm::makeArrayRef<int>({2, 1})); | |||
3238 | ||||
3239 | setShadow(&I, Shadow); | |||
3240 | setOriginForNaryOp(I); | |||
3241 | } | |||
3242 | ||||
3243 | void handleBinarySdIntrinsic(IntrinsicInst &I) { | |||
3244 | IRBuilder<> IRB(&I); | |||
3245 | Value *First = getShadow(&I, 0); | |||
3246 | Value *Second = getShadow(&I, 1); | |||
3247 | Value *OrShadow = IRB.CreateOr(First, Second); | |||
3248 | // High word of first operand, low word of both OR'd together | |||
3249 | Value *Shadow = IRB.CreateShuffleVector(First, OrShadow, | |||
3250 | llvm::makeArrayRef<int>({2, 1})); | |||
3251 | ||||
3252 | setShadow(&I, Shadow); | |||
3253 | setOriginForNaryOp(I); | |||
3254 | } | |||
3255 | ||||
3256 | // Instrument abs intrinsic. | |||
3257 | // handleUnknownIntrinsic can't handle it because of the last | |||
3258 | // is_int_min_poison argument which does not match the result type. | |||
3259 | void handleAbsIntrinsic(IntrinsicInst &I) { | |||
3260 | assert(I.getType()->isIntOrIntVectorTy())((void)0); | |||
3261 | assert(I.getArgOperand(0)->getType() == I.getType())((void)0); | |||
3262 | ||||
3263 | // FIXME: Handle is_int_min_poison. | |||
3264 | IRBuilder<> IRB(&I); | |||
3265 | setShadow(&I, getShadow(&I, 0)); | |||
3266 | setOrigin(&I, getOrigin(&I, 0)); | |||
3267 | } | |||
3268 | ||||
3269 | void visitIntrinsicInst(IntrinsicInst &I) { | |||
3270 | switch (I.getIntrinsicID()) { | |||
3271 | case Intrinsic::abs: | |||
3272 | handleAbsIntrinsic(I); | |||
3273 | break; | |||
3274 | case Intrinsic::lifetime_start: | |||
3275 | handleLifetimeStart(I); | |||
3276 | break; | |||
3277 | case Intrinsic::launder_invariant_group: | |||
3278 | case Intrinsic::strip_invariant_group: | |||
3279 | handleInvariantGroup(I); | |||
3280 | break; | |||
3281 | case Intrinsic::bswap: | |||
3282 | handleBswap(I); | |||
3283 | break; | |||
3284 | case Intrinsic::masked_store: | |||
3285 | handleMaskedStore(I); | |||
3286 | break; | |||
3287 | case Intrinsic::masked_load: | |||
3288 | handleMaskedLoad(I); | |||
3289 | break; | |||
3290 | case Intrinsic::vector_reduce_and: | |||
3291 | handleVectorReduceAndIntrinsic(I); | |||
3292 | break; | |||
3293 | case Intrinsic::vector_reduce_or: | |||
3294 | handleVectorReduceOrIntrinsic(I); | |||
3295 | break; | |||
3296 | case Intrinsic::vector_reduce_add: | |||
3297 | case Intrinsic::vector_reduce_xor: | |||
3298 | case Intrinsic::vector_reduce_mul: | |||
3299 | handleVectorReduceIntrinsic(I); | |||
3300 | break; | |||
3301 | case Intrinsic::x86_sse_stmxcsr: | |||
3302 | handleStmxcsr(I); | |||
3303 | break; | |||
3304 | case Intrinsic::x86_sse_ldmxcsr: | |||
3305 | handleLdmxcsr(I); | |||
3306 | break; | |||
3307 | case Intrinsic::x86_avx512_vcvtsd2usi64: | |||
3308 | case Intrinsic::x86_avx512_vcvtsd2usi32: | |||
3309 | case Intrinsic::x86_avx512_vcvtss2usi64: | |||
3310 | case Intrinsic::x86_avx512_vcvtss2usi32: | |||
3311 | case Intrinsic::x86_avx512_cvttss2usi64: | |||
3312 | case Intrinsic::x86_avx512_cvttss2usi: | |||
3313 | case Intrinsic::x86_avx512_cvttsd2usi64: | |||
3314 | case Intrinsic::x86_avx512_cvttsd2usi: | |||
3315 | case Intrinsic::x86_avx512_cvtusi2ss: | |||
3316 | case Intrinsic::x86_avx512_cvtusi642sd: | |||
3317 | case Intrinsic::x86_avx512_cvtusi642ss: | |||
3318 | handleVectorConvertIntrinsic(I, 1, true); | |||
3319 | break; | |||
3320 | case Intrinsic::x86_sse2_cvtsd2si64: | |||
3321 | case Intrinsic::x86_sse2_cvtsd2si: | |||
3322 | case Intrinsic::x86_sse2_cvtsd2ss: | |||
3323 | case Intrinsic::x86_sse2_cvttsd2si64: | |||
3324 | case Intrinsic::x86_sse2_cvttsd2si: | |||
3325 | case Intrinsic::x86_sse_cvtss2si64: | |||
3326 | case Intrinsic::x86_sse_cvtss2si: | |||
3327 | case Intrinsic::x86_sse_cvttss2si64: | |||
3328 | case Intrinsic::x86_sse_cvttss2si: | |||
3329 | handleVectorConvertIntrinsic(I, 1); | |||
3330 | break; | |||
3331 | case Intrinsic::x86_sse_cvtps2pi: | |||
3332 | case Intrinsic::x86_sse_cvttps2pi: | |||
3333 | handleVectorConvertIntrinsic(I, 2); | |||
3334 | break; | |||
3335 | ||||
3336 | case Intrinsic::x86_avx512_psll_w_512: | |||
3337 | case Intrinsic::x86_avx512_psll_d_512: | |||
3338 | case Intrinsic::x86_avx512_psll_q_512: | |||
3339 | case Intrinsic::x86_avx512_pslli_w_512: | |||
3340 | case Intrinsic::x86_avx512_pslli_d_512: | |||
3341 | case Intrinsic::x86_avx512_pslli_q_512: | |||
3342 | case Intrinsic::x86_avx512_psrl_w_512: | |||
3343 | case Intrinsic::x86_avx512_psrl_d_512: | |||
3344 | case Intrinsic::x86_avx512_psrl_q_512: | |||
3345 | case Intrinsic::x86_avx512_psra_w_512: | |||
3346 | case Intrinsic::x86_avx512_psra_d_512: | |||
3347 | case Intrinsic::x86_avx512_psra_q_512: | |||
3348 | case Intrinsic::x86_avx512_psrli_w_512: | |||
3349 | case Intrinsic::x86_avx512_psrli_d_512: | |||
3350 | case Intrinsic::x86_avx512_psrli_q_512: | |||
3351 | case Intrinsic::x86_avx512_psrai_w_512: | |||
3352 | case Intrinsic::x86_avx512_psrai_d_512: | |||
3353 | case Intrinsic::x86_avx512_psrai_q_512: | |||
3354 | case Intrinsic::x86_avx512_psra_q_256: | |||
3355 | case Intrinsic::x86_avx512_psra_q_128: | |||
3356 | case Intrinsic::x86_avx512_psrai_q_256: | |||
3357 | case Intrinsic::x86_avx512_psrai_q_128: | |||
3358 | case Intrinsic::x86_avx2_psll_w: | |||
3359 | case Intrinsic::x86_avx2_psll_d: | |||
3360 | case Intrinsic::x86_avx2_psll_q: | |||
3361 | case Intrinsic::x86_avx2_pslli_w: | |||
3362 | case Intrinsic::x86_avx2_pslli_d: | |||
3363 | case Intrinsic::x86_avx2_pslli_q: | |||
3364 | case Intrinsic::x86_avx2_psrl_w: | |||
3365 | case Intrinsic::x86_avx2_psrl_d: | |||
3366 | case Intrinsic::x86_avx2_psrl_q: | |||
3367 | case Intrinsic::x86_avx2_psra_w: | |||
3368 | case Intrinsic::x86_avx2_psra_d: | |||
3369 | case Intrinsic::x86_avx2_psrli_w: | |||
3370 | case Intrinsic::x86_avx2_psrli_d: | |||
3371 | case Intrinsic::x86_avx2_psrli_q: | |||
3372 | case Intrinsic::x86_avx2_psrai_w: | |||
3373 | case Intrinsic::x86_avx2_psrai_d: | |||
3374 | case Intrinsic::x86_sse2_psll_w: | |||
3375 | case Intrinsic::x86_sse2_psll_d: | |||
3376 | case Intrinsic::x86_sse2_psll_q: | |||
3377 | case Intrinsic::x86_sse2_pslli_w: | |||
3378 | case Intrinsic::x86_sse2_pslli_d: | |||
3379 | case Intrinsic::x86_sse2_pslli_q: | |||
3380 | case Intrinsic::x86_sse2_psrl_w: | |||
3381 | case Intrinsic::x86_sse2_psrl_d: | |||
3382 | case Intrinsic::x86_sse2_psrl_q: | |||
3383 | case Intrinsic::x86_sse2_psra_w: | |||
3384 | case Intrinsic::x86_sse2_psra_d: | |||
3385 | case Intrinsic::x86_sse2_psrli_w: | |||
3386 | case Intrinsic::x86_sse2_psrli_d: | |||
3387 | case Intrinsic::x86_sse2_psrli_q: | |||
3388 | case Intrinsic::x86_sse2_psrai_w: | |||
3389 | case Intrinsic::x86_sse2_psrai_d: | |||
3390 | case Intrinsic::x86_mmx_psll_w: | |||
3391 | case Intrinsic::x86_mmx_psll_d: | |||
3392 | case Intrinsic::x86_mmx_psll_q: | |||
3393 | case Intrinsic::x86_mmx_pslli_w: | |||
3394 | case Intrinsic::x86_mmx_pslli_d: | |||
3395 | case Intrinsic::x86_mmx_pslli_q: | |||
3396 | case Intrinsic::x86_mmx_psrl_w: | |||
3397 | case Intrinsic::x86_mmx_psrl_d: | |||
3398 | case Intrinsic::x86_mmx_psrl_q: | |||
3399 | case Intrinsic::x86_mmx_psra_w: | |||
3400 | case Intrinsic::x86_mmx_psra_d: | |||
3401 | case Intrinsic::x86_mmx_psrli_w: | |||
3402 | case Intrinsic::x86_mmx_psrli_d: | |||
3403 | case Intrinsic::x86_mmx_psrli_q: | |||
3404 | case Intrinsic::x86_mmx_psrai_w: | |||
3405 | case Intrinsic::x86_mmx_psrai_d: | |||
3406 | handleVectorShiftIntrinsic(I, /* Variable */ false); | |||
3407 | break; | |||
3408 | case Intrinsic::x86_avx2_psllv_d: | |||
3409 | case Intrinsic::x86_avx2_psllv_d_256: | |||
3410 | case Intrinsic::x86_avx512_psllv_d_512: | |||
3411 | case Intrinsic::x86_avx2_psllv_q: | |||
3412 | case Intrinsic::x86_avx2_psllv_q_256: | |||
3413 | case Intrinsic::x86_avx512_psllv_q_512: | |||
3414 | case Intrinsic::x86_avx2_psrlv_d: | |||
3415 | case Intrinsic::x86_avx2_psrlv_d_256: | |||
3416 | case Intrinsic::x86_avx512_psrlv_d_512: | |||
3417 | case Intrinsic::x86_avx2_psrlv_q: | |||
3418 | case Intrinsic::x86_avx2_psrlv_q_256: | |||
3419 | case Intrinsic::x86_avx512_psrlv_q_512: | |||
3420 | case Intrinsic::x86_avx2_psrav_d: | |||
3421 | case Intrinsic::x86_avx2_psrav_d_256: | |||
3422 | case Intrinsic::x86_avx512_psrav_d_512: | |||
3423 | case Intrinsic::x86_avx512_psrav_q_128: | |||
3424 | case Intrinsic::x86_avx512_psrav_q_256: | |||
3425 | case Intrinsic::x86_avx512_psrav_q_512: | |||
3426 | handleVectorShiftIntrinsic(I, /* Variable */ true); | |||
3427 | break; | |||
3428 | ||||
3429 | case Intrinsic::x86_sse2_packsswb_128: | |||
3430 | case Intrinsic::x86_sse2_packssdw_128: | |||
3431 | case Intrinsic::x86_sse2_packuswb_128: | |||
3432 | case Intrinsic::x86_sse41_packusdw: | |||
3433 | case Intrinsic::x86_avx2_packsswb: | |||
3434 | case Intrinsic::x86_avx2_packssdw: | |||
3435 | case Intrinsic::x86_avx2_packuswb: | |||
3436 | case Intrinsic::x86_avx2_packusdw: | |||
3437 | handleVectorPackIntrinsic(I); | |||
3438 | break; | |||
3439 | ||||
3440 | case Intrinsic::x86_mmx_packsswb: | |||
3441 | case Intrinsic::x86_mmx_packuswb: | |||
3442 | handleVectorPackIntrinsic(I, 16); | |||
3443 | break; | |||
3444 | ||||
3445 | case Intrinsic::x86_mmx_packssdw: | |||
3446 | handleVectorPackIntrinsic(I, 32); | |||
3447 | break; | |||
3448 | ||||
3449 | case Intrinsic::x86_mmx_psad_bw: | |||
3450 | case Intrinsic::x86_sse2_psad_bw: | |||
3451 | case Intrinsic::x86_avx2_psad_bw: | |||
3452 | handleVectorSadIntrinsic(I); | |||
3453 | break; | |||
3454 | ||||
3455 | case Intrinsic::x86_sse2_pmadd_wd: | |||
3456 | case Intrinsic::x86_avx2_pmadd_wd: | |||
3457 | case Intrinsic::x86_ssse3_pmadd_ub_sw_128: | |||
3458 | case Intrinsic::x86_avx2_pmadd_ub_sw: | |||
3459 | handleVectorPmaddIntrinsic(I); | |||
3460 | break; | |||
3461 | ||||
3462 | case Intrinsic::x86_ssse3_pmadd_ub_sw: | |||
3463 | handleVectorPmaddIntrinsic(I, 8); | |||
3464 | break; | |||
3465 | ||||
3466 | case Intrinsic::x86_mmx_pmadd_wd: | |||
3467 | handleVectorPmaddIntrinsic(I, 16); | |||
3468 | break; | |||
3469 | ||||
3470 | case Intrinsic::x86_sse_cmp_ss: | |||
3471 | case Intrinsic::x86_sse2_cmp_sd: | |||
3472 | case Intrinsic::x86_sse_comieq_ss: | |||
3473 | case Intrinsic::x86_sse_comilt_ss: | |||
3474 | case Intrinsic::x86_sse_comile_ss: | |||
3475 | case Intrinsic::x86_sse_comigt_ss: | |||
3476 | case Intrinsic::x86_sse_comige_ss: | |||
3477 | case Intrinsic::x86_sse_comineq_ss: | |||
3478 | case Intrinsic::x86_sse_ucomieq_ss: | |||
3479 | case Intrinsic::x86_sse_ucomilt_ss: | |||
3480 | case Intrinsic::x86_sse_ucomile_ss: | |||
3481 | case Intrinsic::x86_sse_ucomigt_ss: | |||
3482 | case Intrinsic::x86_sse_ucomige_ss: | |||
3483 | case Intrinsic::x86_sse_ucomineq_ss: | |||
3484 | case Intrinsic::x86_sse2_comieq_sd: | |||
3485 | case Intrinsic::x86_sse2_comilt_sd: | |||
3486 | case Intrinsic::x86_sse2_comile_sd: | |||
3487 | case Intrinsic::x86_sse2_comigt_sd: | |||
3488 | case Intrinsic::x86_sse2_comige_sd: | |||
3489 | case Intrinsic::x86_sse2_comineq_sd: | |||
3490 | case Intrinsic::x86_sse2_ucomieq_sd: | |||
3491 | case Intrinsic::x86_sse2_ucomilt_sd: | |||
3492 | case Intrinsic::x86_sse2_ucomile_sd: | |||
3493 | case Intrinsic::x86_sse2_ucomigt_sd: | |||
3494 | case Intrinsic::x86_sse2_ucomige_sd: | |||
3495 | case Intrinsic::x86_sse2_ucomineq_sd: | |||
3496 | handleVectorCompareScalarIntrinsic(I); | |||
3497 | break; | |||
3498 | ||||
3499 | case Intrinsic::x86_sse_cmp_ps: | |||
3500 | case Intrinsic::x86_sse2_cmp_pd: | |||
3501 | // FIXME: For x86_avx_cmp_pd_256 and x86_avx_cmp_ps_256 this function | |||
3502 | // generates reasonably looking IR that fails in the backend with "Do not | |||
3503 | // know how to split the result of this operator!". | |||
3504 | handleVectorComparePackedIntrinsic(I); | |||
3505 | break; | |||
3506 | ||||
3507 | case Intrinsic::x86_bmi_bextr_32: | |||
3508 | case Intrinsic::x86_bmi_bextr_64: | |||
3509 | case Intrinsic::x86_bmi_bzhi_32: | |||
3510 | case Intrinsic::x86_bmi_bzhi_64: | |||
3511 | case Intrinsic::x86_bmi_pdep_32: | |||
3512 | case Intrinsic::x86_bmi_pdep_64: | |||
3513 | case Intrinsic::x86_bmi_pext_32: | |||
3514 | case Intrinsic::x86_bmi_pext_64: | |||
3515 | handleBmiIntrinsic(I); | |||
3516 | break; | |||
3517 | ||||
3518 | case Intrinsic::x86_pclmulqdq: | |||
3519 | case Intrinsic::x86_pclmulqdq_256: | |||
3520 | case Intrinsic::x86_pclmulqdq_512: | |||
3521 | handlePclmulIntrinsic(I); | |||
3522 | break; | |||
3523 | ||||
3524 | case Intrinsic::x86_sse41_round_sd: | |||
3525 | handleUnarySdIntrinsic(I); | |||
3526 | break; | |||
3527 | case Intrinsic::x86_sse2_max_sd: | |||
3528 | case Intrinsic::x86_sse2_min_sd: | |||
3529 | handleBinarySdIntrinsic(I); | |||
3530 | break; | |||
3531 | ||||
3532 | case Intrinsic::fshl: | |||
3533 | case Intrinsic::fshr: | |||
3534 | handleFunnelShift(I); | |||
3535 | break; | |||
3536 | ||||
3537 | case Intrinsic::is_constant: | |||
3538 | // The result of llvm.is.constant() is always defined. | |||
3539 | setShadow(&I, getCleanShadow(&I)); | |||
3540 | setOrigin(&I, getCleanOrigin()); | |||
3541 | break; | |||
3542 | ||||
3543 | default: | |||
3544 | if (!handleUnknownIntrinsic(I)) | |||
3545 | visitInstruction(I); | |||
3546 | break; | |||
3547 | } | |||
3548 | } | |||
3549 | ||||
3550 | void visitLibAtomicLoad(CallBase &CB) { | |||
3551 | // Since we use getNextNode here, we can't have CB terminate the BB. | |||
3552 | assert(isa<CallInst>(CB))((void)0); | |||
3553 | ||||
3554 | IRBuilder<> IRB(&CB); | |||
3555 | Value *Size = CB.getArgOperand(0); | |||
3556 | Value *SrcPtr = CB.getArgOperand(1); | |||
3557 | Value *DstPtr = CB.getArgOperand(2); | |||
3558 | Value *Ordering = CB.getArgOperand(3); | |||
3559 | // Convert the call to have at least Acquire ordering to make sure | |||
3560 | // the shadow operations aren't reordered before it. | |||
3561 | Value *NewOrdering = | |||
3562 | IRB.CreateExtractElement(makeAddAcquireOrderingTable(IRB), Ordering); | |||
3563 | CB.setArgOperand(3, NewOrdering); | |||
3564 | ||||
3565 | IRBuilder<> NextIRB(CB.getNextNode()); | |||
3566 | NextIRB.SetCurrentDebugLocation(CB.getDebugLoc()); | |||
3567 | ||||
3568 | Value *SrcShadowPtr, *SrcOriginPtr; | |||
3569 | std::tie(SrcShadowPtr, SrcOriginPtr) = | |||
3570 | getShadowOriginPtr(SrcPtr, NextIRB, NextIRB.getInt8Ty(), Align(1), | |||
3571 | /*isStore*/ false); | |||
3572 | Value *DstShadowPtr = | |||
3573 | getShadowOriginPtr(DstPtr, NextIRB, NextIRB.getInt8Ty(), Align(1), | |||
3574 | /*isStore*/ true) | |||
3575 | .first; | |||
3576 | ||||
3577 | NextIRB.CreateMemCpy(DstShadowPtr, Align(1), SrcShadowPtr, Align(1), Size); | |||
3578 | if (MS.TrackOrigins) { | |||
3579 | Value *SrcOrigin = NextIRB.CreateAlignedLoad(MS.OriginTy, SrcOriginPtr, | |||
3580 | kMinOriginAlignment); | |||
3581 | Value *NewOrigin = updateOrigin(SrcOrigin, NextIRB); | |||
3582 | NextIRB.CreateCall(MS.MsanSetOriginFn, {DstPtr, Size, NewOrigin}); | |||
3583 | } | |||
3584 | } | |||
3585 | ||||
3586 | void visitLibAtomicStore(CallBase &CB) { | |||
3587 | IRBuilder<> IRB(&CB); | |||
3588 | Value *Size = CB.getArgOperand(0); | |||
3589 | Value *DstPtr = CB.getArgOperand(2); | |||
3590 | Value *Ordering = CB.getArgOperand(3); | |||
3591 | // Convert the call to have at least Release ordering to make sure | |||
3592 | // the shadow operations aren't reordered after it. | |||
3593 | Value *NewOrdering = | |||
3594 | IRB.CreateExtractElement(makeAddReleaseOrderingTable(IRB), Ordering); | |||
3595 | CB.setArgOperand(3, NewOrdering); | |||
3596 | ||||
3597 | Value *DstShadowPtr = | |||
3598 | getShadowOriginPtr(DstPtr, IRB, IRB.getInt8Ty(), Align(1), | |||
3599 | /*isStore*/ true) | |||
3600 | .first; | |||
3601 | ||||
3602 | // Atomic store always paints clean shadow/origin. See file header. | |||
3603 | IRB.CreateMemSet(DstShadowPtr, getCleanShadow(IRB.getInt8Ty()), Size, | |||
3604 | Align(1)); | |||
3605 | } | |||
3606 | ||||
3607 | void visitCallBase(CallBase &CB) { | |||
3608 | assert(!CB.getMetadata("nosanitize"))((void)0); | |||
3609 | if (CB.isInlineAsm()) { | |||
3610 | // For inline asm (either a call to asm function, or callbr instruction), | |||
3611 | // do the usual thing: check argument shadow and mark all outputs as | |||
3612 | // clean. Note that any side effects of the inline asm that are not | |||
3613 | // immediately visible in its constraints are not handled. | |||
3614 | if (ClHandleAsmConservative && MS.CompileKernel) | |||
3615 | visitAsmInstruction(CB); | |||
3616 | else | |||
3617 | visitInstruction(CB); | |||
3618 | return; | |||
3619 | } | |||
3620 | LibFunc LF; | |||
3621 | if (TLI->getLibFunc(CB, LF)) { | |||
3622 | // libatomic.a functions need to have special handling because there isn't | |||
3623 | // a good way to intercept them or compile the library with | |||
3624 | // instrumentation. | |||
3625 | switch (LF) { | |||
3626 | case LibFunc_atomic_load: | |||
3627 | if (!isa<CallInst>(CB)) { | |||
3628 | llvm::errs() << "MSAN -- cannot instrument invoke of libatomic load." | |||
3629 | "Ignoring!\n"; | |||
3630 | break; | |||
3631 | } | |||
3632 | visitLibAtomicLoad(CB); | |||
3633 | return; | |||
3634 | case LibFunc_atomic_store: | |||
3635 | visitLibAtomicStore(CB); | |||
3636 | return; | |||
3637 | default: | |||
3638 | break; | |||
3639 | } | |||
3640 | } | |||
3641 | ||||
3642 | if (auto *Call = dyn_cast<CallInst>(&CB)) { | |||
3643 | assert(!isa<IntrinsicInst>(Call) && "intrinsics are handled elsewhere")((void)0); | |||
3644 | ||||
3645 | // We are going to insert code that relies on the fact that the callee | |||
3646 | // will become a non-readonly function after it is instrumented by us. To | |||
3647 | // prevent this code from being optimized out, mark that function | |||
3648 | // non-readonly in advance. | |||
3649 | AttrBuilder B; | |||
3650 | B.addAttribute(Attribute::ReadOnly) | |||
3651 | .addAttribute(Attribute::ReadNone) | |||
3652 | .addAttribute(Attribute::WriteOnly) | |||
3653 | .addAttribute(Attribute::ArgMemOnly) | |||
3654 | .addAttribute(Attribute::Speculatable); | |||
3655 | ||||
3656 | Call->removeAttributes(AttributeList::FunctionIndex, B); | |||
3657 | if (Function *Func = Call->getCalledFunction()) { | |||
3658 | Func->removeAttributes(AttributeList::FunctionIndex, B); | |||
3659 | } | |||
3660 | ||||
3661 | maybeMarkSanitizerLibraryCallNoBuiltin(Call, TLI); | |||
3662 | } | |||
3663 | IRBuilder<> IRB(&CB); | |||
3664 | bool MayCheckCall = ClEagerChecks; | |||
3665 | if (Function *Func = CB.getCalledFunction()) { | |||
3666 | // __sanitizer_unaligned_{load,store} functions may be called by users | |||
3667 | // and always expects shadows in the TLS. So don't check them. | |||
3668 | MayCheckCall &= !Func->getName().startswith("__sanitizer_unaligned_"); | |||
3669 | } | |||
3670 | ||||
3671 | unsigned ArgOffset = 0; | |||
3672 | LLVM_DEBUG(dbgs() << " CallSite: " << CB << "\n")do { } while (false); | |||
3673 | for (auto ArgIt = CB.arg_begin(), End = CB.arg_end(); ArgIt != End; | |||
3674 | ++ArgIt) { | |||
3675 | Value *A = *ArgIt; | |||
3676 | unsigned i = ArgIt - CB.arg_begin(); | |||
3677 | if (!A->getType()->isSized()) { | |||
3678 | LLVM_DEBUG(dbgs() << "Arg " << i << " is not sized: " << CB << "\n")do { } while (false); | |||
3679 | continue; | |||
3680 | } | |||
3681 | unsigned Size = 0; | |||
3682 | Value *Store = nullptr; | |||
3683 | // Compute the Shadow for arg even if it is ByVal, because | |||
3684 | // in that case getShadow() will copy the actual arg shadow to | |||
3685 | // __msan_param_tls. | |||
3686 | Value *ArgShadow = getShadow(A); | |||
3687 | Value *ArgShadowBase = getShadowPtrForArgument(A, IRB, ArgOffset); | |||
3688 | LLVM_DEBUG(dbgs() << " Arg#" << i << ": " << *Ado { } while (false) | |||
3689 | << " Shadow: " << *ArgShadow << "\n")do { } while (false); | |||
3690 | bool ArgIsInitialized = false; | |||
3691 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
3692 | ||||
3693 | bool ByVal = CB.paramHasAttr(i, Attribute::ByVal); | |||
3694 | bool NoUndef = CB.paramHasAttr(i, Attribute::NoUndef); | |||
3695 | bool EagerCheck = MayCheckCall && !ByVal && NoUndef; | |||
3696 | ||||
3697 | if (EagerCheck) { | |||
3698 | insertShadowCheck(A, &CB); | |||
3699 | continue; | |||
3700 | } | |||
3701 | if (ByVal) { | |||
3702 | // ByVal requires some special handling as it's too big for a single | |||
3703 | // load | |||
3704 | assert(A->getType()->isPointerTy() &&((void)0) | |||
3705 | "ByVal argument is not a pointer!")((void)0); | |||
3706 | Size = DL.getTypeAllocSize(CB.getParamByValType(i)); | |||
3707 | if (ArgOffset + Size > kParamTLSSize) break; | |||
3708 | const MaybeAlign ParamAlignment(CB.getParamAlign(i)); | |||
3709 | MaybeAlign Alignment = llvm::None; | |||
3710 | if (ParamAlignment) | |||
3711 | Alignment = std::min(*ParamAlignment, kShadowTLSAlignment); | |||
3712 | Value *AShadowPtr = | |||
3713 | getShadowOriginPtr(A, IRB, IRB.getInt8Ty(), Alignment, | |||
3714 | /*isStore*/ false) | |||
3715 | .first; | |||
3716 | ||||
3717 | Store = IRB.CreateMemCpy(ArgShadowBase, Alignment, AShadowPtr, | |||
3718 | Alignment, Size); | |||
3719 | // TODO(glider): need to copy origins. | |||
3720 | } else { | |||
3721 | // Any other parameters mean we need bit-grained tracking of uninit data | |||
3722 | Size = DL.getTypeAllocSize(A->getType()); | |||
3723 | if (ArgOffset + Size > kParamTLSSize) break; | |||
3724 | Store = IRB.CreateAlignedStore(ArgShadow, ArgShadowBase, | |||
3725 | kShadowTLSAlignment); | |||
3726 | Constant *Cst = dyn_cast<Constant>(ArgShadow); | |||
3727 | if (Cst && Cst->isNullValue()) ArgIsInitialized = true; | |||
3728 | } | |||
3729 | if (MS.TrackOrigins && !ArgIsInitialized) | |||
3730 | IRB.CreateStore(getOrigin(A), | |||
3731 | getOriginPtrForArgument(A, IRB, ArgOffset)); | |||
3732 | (void)Store; | |||
3733 | assert(Size != 0 && Store != nullptr)((void)0); | |||
3734 | LLVM_DEBUG(dbgs() << " Param:" << *Store << "\n")do { } while (false); | |||
3735 | ArgOffset += alignTo(Size, kShadowTLSAlignment); | |||
3736 | } | |||
3737 | LLVM_DEBUG(dbgs() << " done with call args\n")do { } while (false); | |||
3738 | ||||
3739 | FunctionType *FT = CB.getFunctionType(); | |||
3740 | if (FT->isVarArg()) { | |||
3741 | VAHelper->visitCallBase(CB, IRB); | |||
3742 | } | |||
3743 | ||||
3744 | // Now, get the shadow for the RetVal. | |||
3745 | if (!CB.getType()->isSized()) | |||
3746 | return; | |||
3747 | // Don't emit the epilogue for musttail call returns. | |||
3748 | if (isa<CallInst>(CB) && cast<CallInst>(CB).isMustTailCall()) | |||
3749 | return; | |||
3750 | ||||
3751 | if (MayCheckCall && CB.hasRetAttr(Attribute::NoUndef)) { | |||
3752 | setShadow(&CB, getCleanShadow(&CB)); | |||
3753 | setOrigin(&CB, getCleanOrigin()); | |||
3754 | return; | |||
3755 | } | |||
3756 | ||||
3757 | IRBuilder<> IRBBefore(&CB); | |||
3758 | // Until we have full dynamic coverage, make sure the retval shadow is 0. | |||
3759 | Value *Base = getShadowPtrForRetval(&CB, IRBBefore); | |||
3760 | IRBBefore.CreateAlignedStore(getCleanShadow(&CB), Base, | |||
3761 | kShadowTLSAlignment); | |||
3762 | BasicBlock::iterator NextInsn; | |||
3763 | if (isa<CallInst>(CB)) { | |||
3764 | NextInsn = ++CB.getIterator(); | |||
3765 | assert(NextInsn != CB.getParent()->end())((void)0); | |||
3766 | } else { | |||
3767 | BasicBlock *NormalDest = cast<InvokeInst>(CB).getNormalDest(); | |||
3768 | if (!NormalDest->getSinglePredecessor()) { | |||
3769 | // FIXME: this case is tricky, so we are just conservative here. | |||
3770 | // Perhaps we need to split the edge between this BB and NormalDest, | |||
3771 | // but a naive attempt to use SplitEdge leads to a crash. | |||
3772 | setShadow(&CB, getCleanShadow(&CB)); | |||
3773 | setOrigin(&CB, getCleanOrigin()); | |||
3774 | return; | |||
3775 | } | |||
3776 | // FIXME: NextInsn is likely in a basic block that has not been visited yet. | |||
3777 | // Anything inserted there will be instrumented by MSan later! | |||
3778 | NextInsn = NormalDest->getFirstInsertionPt(); | |||
3779 | assert(NextInsn != NormalDest->end() &&((void)0) | |||
3780 | "Could not find insertion point for retval shadow load")((void)0); | |||
3781 | } | |||
3782 | IRBuilder<> IRBAfter(&*NextInsn); | |||
3783 | Value *RetvalShadow = IRBAfter.CreateAlignedLoad( | |||
3784 | getShadowTy(&CB), getShadowPtrForRetval(&CB, IRBAfter), | |||
3785 | kShadowTLSAlignment, "_msret"); | |||
3786 | setShadow(&CB, RetvalShadow); | |||
3787 | if (MS.TrackOrigins) | |||
3788 | setOrigin(&CB, IRBAfter.CreateLoad(MS.OriginTy, | |||
3789 | getOriginPtrForRetval(IRBAfter))); | |||
3790 | } | |||
3791 | ||||
3792 | bool isAMustTailRetVal(Value *RetVal) { | |||
3793 | if (auto *I = dyn_cast<BitCastInst>(RetVal)) { | |||
3794 | RetVal = I->getOperand(0); | |||
3795 | } | |||
3796 | if (auto *I = dyn_cast<CallInst>(RetVal)) { | |||
3797 | return I->isMustTailCall(); | |||
3798 | } | |||
3799 | return false; | |||
3800 | } | |||
3801 | ||||
3802 | void visitReturnInst(ReturnInst &I) { | |||
3803 | IRBuilder<> IRB(&I); | |||
3804 | Value *RetVal = I.getReturnValue(); | |||
3805 | if (!RetVal) return; | |||
3806 | // Don't emit the epilogue for musttail call returns. | |||
3807 | if (isAMustTailRetVal(RetVal)) return; | |||
3808 | Value *ShadowPtr = getShadowPtrForRetval(RetVal, IRB); | |||
3809 | bool HasNoUndef = | |||
3810 | F.hasAttribute(AttributeList::ReturnIndex, Attribute::NoUndef); | |||
3811 | bool StoreShadow = !(ClEagerChecks && HasNoUndef); | |||
3812 | // FIXME: Consider using SpecialCaseList to specify a list of functions that | |||
3813 | // must always return fully initialized values. For now, we hardcode "main". | |||
3814 | bool EagerCheck = (ClEagerChecks && HasNoUndef) || (F.getName() == "main"); | |||
3815 | ||||
3816 | Value *Shadow = getShadow(RetVal); | |||
3817 | bool StoreOrigin = true; | |||
3818 | if (EagerCheck) { | |||
3819 | insertShadowCheck(RetVal, &I); | |||
3820 | Shadow = getCleanShadow(RetVal); | |||
3821 | StoreOrigin = false; | |||
3822 | } | |||
3823 | ||||
3824 | // The caller may still expect information passed over TLS if we pass our | |||
3825 | // check | |||
3826 | if (StoreShadow) { | |||
3827 | IRB.CreateAlignedStore(Shadow, ShadowPtr, kShadowTLSAlignment); | |||
3828 | if (MS.TrackOrigins && StoreOrigin) | |||
3829 | IRB.CreateStore(getOrigin(RetVal), getOriginPtrForRetval(IRB)); | |||
3830 | } | |||
3831 | } | |||
3832 | ||||
3833 | void visitPHINode(PHINode &I) { | |||
3834 | IRBuilder<> IRB(&I); | |||
3835 | if (!PropagateShadow) { | |||
3836 | setShadow(&I, getCleanShadow(&I)); | |||
3837 | setOrigin(&I, getCleanOrigin()); | |||
3838 | return; | |||
3839 | } | |||
3840 | ||||
3841 | ShadowPHINodes.push_back(&I); | |||
3842 | setShadow(&I, IRB.CreatePHI(getShadowTy(&I), I.getNumIncomingValues(), | |||
3843 | "_msphi_s")); | |||
3844 | if (MS.TrackOrigins) | |||
3845 | setOrigin(&I, IRB.CreatePHI(MS.OriginTy, I.getNumIncomingValues(), | |||
3846 | "_msphi_o")); | |||
3847 | } | |||
3848 | ||||
3849 | Value *getLocalVarDescription(AllocaInst &I) { | |||
3850 | SmallString<2048> StackDescriptionStorage; | |||
3851 | raw_svector_ostream StackDescription(StackDescriptionStorage); | |||
3852 | // We create a string with a description of the stack allocation and | |||
3853 | // pass it into __msan_set_alloca_origin. | |||
3854 | // It will be printed by the run-time if stack-originated UMR is found. | |||
3855 | // The first 4 bytes of the string are set to '----' and will be replaced | |||
3856 | // by __msan_va_arg_overflow_size_tls at the first call. | |||
3857 | StackDescription << "----" << I.getName() << "@" << F.getName(); | |||
3858 | return createPrivateNonConstGlobalForString(*F.getParent(), | |||
3859 | StackDescription.str()); | |||
3860 | } | |||
3861 | ||||
3862 | void poisonAllocaUserspace(AllocaInst &I, IRBuilder<> &IRB, Value *Len) { | |||
3863 | if (PoisonStack && ClPoisonStackWithCall) { | |||
3864 | IRB.CreateCall(MS.MsanPoisonStackFn, | |||
3865 | {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len}); | |||
3866 | } else { | |||
3867 | Value *ShadowBase, *OriginBase; | |||
3868 | std::tie(ShadowBase, OriginBase) = getShadowOriginPtr( | |||
3869 | &I, IRB, IRB.getInt8Ty(), Align(1), /*isStore*/ true); | |||
3870 | ||||
3871 | Value *PoisonValue = IRB.getInt8(PoisonStack ? ClPoisonStackPattern : 0); | |||
3872 | IRB.CreateMemSet(ShadowBase, PoisonValue, Len, | |||
3873 | MaybeAlign(I.getAlignment())); | |||
3874 | } | |||
3875 | ||||
3876 | if (PoisonStack && MS.TrackOrigins) { | |||
3877 | Value *Descr = getLocalVarDescription(I); | |||
3878 | IRB.CreateCall(MS.MsanSetAllocaOrigin4Fn, | |||
3879 | {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len, | |||
3880 | IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy()), | |||
3881 | IRB.CreatePointerCast(&F, MS.IntptrTy)}); | |||
3882 | } | |||
3883 | } | |||
3884 | ||||
3885 | void poisonAllocaKmsan(AllocaInst &I, IRBuilder<> &IRB, Value *Len) { | |||
3886 | Value *Descr = getLocalVarDescription(I); | |||
3887 | if (PoisonStack) { | |||
3888 | IRB.CreateCall(MS.MsanPoisonAllocaFn, | |||
3889 | {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len, | |||
3890 | IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy())}); | |||
3891 | } else { | |||
3892 | IRB.CreateCall(MS.MsanUnpoisonAllocaFn, | |||
3893 | {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len}); | |||
3894 | } | |||
3895 | } | |||
3896 | ||||
3897 | void instrumentAlloca(AllocaInst &I, Instruction *InsPoint = nullptr) { | |||
3898 | if (!InsPoint) | |||
3899 | InsPoint = &I; | |||
3900 | IRBuilder<> IRB(InsPoint->getNextNode()); | |||
3901 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
3902 | uint64_t TypeSize = DL.getTypeAllocSize(I.getAllocatedType()); | |||
3903 | Value *Len = ConstantInt::get(MS.IntptrTy, TypeSize); | |||
3904 | if (I.isArrayAllocation()) | |||
3905 | Len = IRB.CreateMul(Len, I.getArraySize()); | |||
3906 | ||||
3907 | if (MS.CompileKernel) | |||
3908 | poisonAllocaKmsan(I, IRB, Len); | |||
3909 | else | |||
3910 | poisonAllocaUserspace(I, IRB, Len); | |||
3911 | } | |||
3912 | ||||
3913 | void visitAllocaInst(AllocaInst &I) { | |||
3914 | setShadow(&I, getCleanShadow(&I)); | |||
3915 | setOrigin(&I, getCleanOrigin()); | |||
3916 | // We'll get to this alloca later unless it's poisoned at the corresponding | |||
3917 | // llvm.lifetime.start. | |||
3918 | AllocaSet.insert(&I); | |||
3919 | } | |||
3920 | ||||
3921 | void visitSelectInst(SelectInst& I) { | |||
3922 | IRBuilder<> IRB(&I); | |||
3923 | // a = select b, c, d | |||
3924 | Value *B = I.getCondition(); | |||
3925 | Value *C = I.getTrueValue(); | |||
3926 | Value *D = I.getFalseValue(); | |||
3927 | Value *Sb = getShadow(B); | |||
3928 | Value *Sc = getShadow(C); | |||
3929 | Value *Sd = getShadow(D); | |||
3930 | ||||
3931 | // Result shadow if condition shadow is 0. | |||
3932 | Value *Sa0 = IRB.CreateSelect(B, Sc, Sd); | |||
3933 | Value *Sa1; | |||
3934 | if (I.getType()->isAggregateType()) { | |||
3935 | // To avoid "sign extending" i1 to an arbitrary aggregate type, we just do | |||
3936 | // an extra "select". This results in much more compact IR. | |||
3937 | // Sa = select Sb, poisoned, (select b, Sc, Sd) | |||
3938 | Sa1 = getPoisonedShadow(getShadowTy(I.getType())); | |||
3939 | } else { | |||
3940 | // Sa = select Sb, [ (c^d) | Sc | Sd ], [ b ? Sc : Sd ] | |||
3941 | // If Sb (condition is poisoned), look for bits in c and d that are equal | |||
3942 | // and both unpoisoned. | |||
3943 | // If !Sb (condition is unpoisoned), simply pick one of Sc and Sd. | |||
3944 | ||||
3945 | // Cast arguments to shadow-compatible type. | |||
3946 | C = CreateAppToShadowCast(IRB, C); | |||
3947 | D = CreateAppToShadowCast(IRB, D); | |||
3948 | ||||
3949 | // Result shadow if condition shadow is 1. | |||
3950 | Sa1 = IRB.CreateOr({IRB.CreateXor(C, D), Sc, Sd}); | |||
3951 | } | |||
3952 | Value *Sa = IRB.CreateSelect(Sb, Sa1, Sa0, "_msprop_select"); | |||
3953 | setShadow(&I, Sa); | |||
3954 | if (MS.TrackOrigins) { | |||
3955 | // Origins are always i32, so any vector conditions must be flattened. | |||
3956 | // FIXME: consider tracking vector origins for app vectors? | |||
3957 | if (B->getType()->isVectorTy()) { | |||
3958 | Type *FlatTy = getShadowTyNoVec(B->getType()); | |||
3959 | B = IRB.CreateICmpNE(IRB.CreateBitCast(B, FlatTy), | |||
3960 | ConstantInt::getNullValue(FlatTy)); | |||
3961 | Sb = IRB.CreateICmpNE(IRB.CreateBitCast(Sb, FlatTy), | |||
3962 | ConstantInt::getNullValue(FlatTy)); | |||
3963 | } | |||
3964 | // a = select b, c, d | |||
3965 | // Oa = Sb ? Ob : (b ? Oc : Od) | |||
3966 | setOrigin( | |||
3967 | &I, IRB.CreateSelect(Sb, getOrigin(I.getCondition()), | |||
3968 | IRB.CreateSelect(B, getOrigin(I.getTrueValue()), | |||
3969 | getOrigin(I.getFalseValue())))); | |||
3970 | } | |||
3971 | } | |||
3972 | ||||
3973 | void visitLandingPadInst(LandingPadInst &I) { | |||
3974 | // Do nothing. | |||
3975 | // See https://github.com/google/sanitizers/issues/504 | |||
3976 | setShadow(&I, getCleanShadow(&I)); | |||
3977 | setOrigin(&I, getCleanOrigin()); | |||
3978 | } | |||
3979 | ||||
3980 | void visitCatchSwitchInst(CatchSwitchInst &I) { | |||
3981 | setShadow(&I, getCleanShadow(&I)); | |||
3982 | setOrigin(&I, getCleanOrigin()); | |||
3983 | } | |||
3984 | ||||
3985 | void visitFuncletPadInst(FuncletPadInst &I) { | |||
3986 | setShadow(&I, getCleanShadow(&I)); | |||
3987 | setOrigin(&I, getCleanOrigin()); | |||
3988 | } | |||
3989 | ||||
3990 | void visitGetElementPtrInst(GetElementPtrInst &I) { | |||
3991 | handleShadowOr(I); | |||
3992 | } | |||
3993 | ||||
3994 | void visitExtractValueInst(ExtractValueInst &I) { | |||
3995 | IRBuilder<> IRB(&I); | |||
3996 | Value *Agg = I.getAggregateOperand(); | |||
3997 | LLVM_DEBUG(dbgs() << "ExtractValue: " << I << "\n")do { } while (false); | |||
3998 | Value *AggShadow = getShadow(Agg); | |||
3999 | LLVM_DEBUG(dbgs() << " AggShadow: " << *AggShadow << "\n")do { } while (false); | |||
4000 | Value *ResShadow = IRB.CreateExtractValue(AggShadow, I.getIndices()); | |||
4001 | LLVM_DEBUG(dbgs() << " ResShadow: " << *ResShadow << "\n")do { } while (false); | |||
4002 | setShadow(&I, ResShadow); | |||
4003 | setOriginForNaryOp(I); | |||
4004 | } | |||
4005 | ||||
4006 | void visitInsertValueInst(InsertValueInst &I) { | |||
4007 | IRBuilder<> IRB(&I); | |||
4008 | LLVM_DEBUG(dbgs() << "InsertValue: " << I << "\n")do { } while (false); | |||
4009 | Value *AggShadow = getShadow(I.getAggregateOperand()); | |||
4010 | Value *InsShadow = getShadow(I.getInsertedValueOperand()); | |||
4011 | LLVM_DEBUG(dbgs() << " AggShadow: " << *AggShadow << "\n")do { } while (false); | |||
4012 | LLVM_DEBUG(dbgs() << " InsShadow: " << *InsShadow << "\n")do { } while (false); | |||
4013 | Value *Res = IRB.CreateInsertValue(AggShadow, InsShadow, I.getIndices()); | |||
4014 | LLVM_DEBUG(dbgs() << " Res: " << *Res << "\n")do { } while (false); | |||
4015 | setShadow(&I, Res); | |||
4016 | setOriginForNaryOp(I); | |||
4017 | } | |||
4018 | ||||
4019 | void dumpInst(Instruction &I) { | |||
4020 | if (CallInst *CI = dyn_cast<CallInst>(&I)) { | |||
4021 | errs() << "ZZZ call " << CI->getCalledFunction()->getName() << "\n"; | |||
4022 | } else { | |||
4023 | errs() << "ZZZ " << I.getOpcodeName() << "\n"; | |||
4024 | } | |||
4025 | errs() << "QQQ " << I << "\n"; | |||
4026 | } | |||
4027 | ||||
4028 | void visitResumeInst(ResumeInst &I) { | |||
4029 | LLVM_DEBUG(dbgs() << "Resume: " << I << "\n")do { } while (false); | |||
4030 | // Nothing to do here. | |||
4031 | } | |||
4032 | ||||
4033 | void visitCleanupReturnInst(CleanupReturnInst &CRI) { | |||
4034 | LLVM_DEBUG(dbgs() << "CleanupReturn: " << CRI << "\n")do { } while (false); | |||
4035 | // Nothing to do here. | |||
4036 | } | |||
4037 | ||||
4038 | void visitCatchReturnInst(CatchReturnInst &CRI) { | |||
4039 | LLVM_DEBUG(dbgs() << "CatchReturn: " << CRI << "\n")do { } while (false); | |||
4040 | // Nothing to do here. | |||
4041 | } | |||
4042 | ||||
4043 | void instrumentAsmArgument(Value *Operand, Instruction &I, IRBuilder<> &IRB, | |||
4044 | const DataLayout &DL, bool isOutput) { | |||
4045 | // For each assembly argument, we check its value for being initialized. | |||
4046 | // If the argument is a pointer, we assume it points to a single element | |||
4047 | // of the corresponding type (or to a 8-byte word, if the type is unsized). | |||
4048 | // Each such pointer is instrumented with a call to the runtime library. | |||
4049 | Type *OpType = Operand->getType(); | |||
4050 | // Check the operand value itself. | |||
4051 | insertShadowCheck(Operand, &I); | |||
4052 | if (!OpType->isPointerTy() || !isOutput) { | |||
4053 | assert(!isOutput)((void)0); | |||
4054 | return; | |||
4055 | } | |||
4056 | Type *ElType = OpType->getPointerElementType(); | |||
4057 | if (!ElType->isSized()) | |||
4058 | return; | |||
4059 | int Size = DL.getTypeStoreSize(ElType); | |||
4060 | Value *Ptr = IRB.CreatePointerCast(Operand, IRB.getInt8PtrTy()); | |||
4061 | Value *SizeVal = ConstantInt::get(MS.IntptrTy, Size); | |||
4062 | IRB.CreateCall(MS.MsanInstrumentAsmStoreFn, {Ptr, SizeVal}); | |||
4063 | } | |||
4064 | ||||
4065 | /// Get the number of output arguments returned by pointers. | |||
4066 | int getNumOutputArgs(InlineAsm *IA, CallBase *CB) { | |||
4067 | int NumRetOutputs = 0; | |||
4068 | int NumOutputs = 0; | |||
4069 | Type *RetTy = cast<Value>(CB)->getType(); | |||
4070 | if (!RetTy->isVoidTy()) { | |||
4071 | // Register outputs are returned via the CallInst return value. | |||
4072 | auto *ST = dyn_cast<StructType>(RetTy); | |||
4073 | if (ST) | |||
4074 | NumRetOutputs = ST->getNumElements(); | |||
4075 | else | |||
4076 | NumRetOutputs = 1; | |||
4077 | } | |||
4078 | InlineAsm::ConstraintInfoVector Constraints = IA->ParseConstraints(); | |||
4079 | for (const InlineAsm::ConstraintInfo &Info : Constraints) { | |||
4080 | switch (Info.Type) { | |||
4081 | case InlineAsm::isOutput: | |||
4082 | NumOutputs++; | |||
4083 | break; | |||
4084 | default: | |||
4085 | break; | |||
4086 | } | |||
4087 | } | |||
4088 | return NumOutputs - NumRetOutputs; | |||
4089 | } | |||
4090 | ||||
4091 | void visitAsmInstruction(Instruction &I) { | |||
4092 | // Conservative inline assembly handling: check for poisoned shadow of | |||
4093 | // asm() arguments, then unpoison the result and all the memory locations | |||
4094 | // pointed to by those arguments. | |||
4095 | // An inline asm() statement in C++ contains lists of input and output | |||
4096 | // arguments used by the assembly code. These are mapped to operands of the | |||
4097 | // CallInst as follows: | |||
4098 | // - nR register outputs ("=r) are returned by value in a single structure | |||
4099 | // (SSA value of the CallInst); | |||
4100 | // - nO other outputs ("=m" and others) are returned by pointer as first | |||
4101 | // nO operands of the CallInst; | |||
4102 | // - nI inputs ("r", "m" and others) are passed to CallInst as the | |||
4103 | // remaining nI operands. | |||
4104 | // The total number of asm() arguments in the source is nR+nO+nI, and the | |||
4105 | // corresponding CallInst has nO+nI+1 operands (the last operand is the | |||
4106 | // function to be called). | |||
4107 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
4108 | CallBase *CB = cast<CallBase>(&I); | |||
4109 | IRBuilder<> IRB(&I); | |||
4110 | InlineAsm *IA = cast<InlineAsm>(CB->getCalledOperand()); | |||
4111 | int OutputArgs = getNumOutputArgs(IA, CB); | |||
4112 | // The last operand of a CallInst is the function itself. | |||
4113 | int NumOperands = CB->getNumOperands() - 1; | |||
4114 | ||||
4115 | // Check input arguments. Doing so before unpoisoning output arguments, so | |||
4116 | // that we won't overwrite uninit values before checking them. | |||
4117 | for (int i = OutputArgs; i < NumOperands; i++) { | |||
4118 | Value *Operand = CB->getOperand(i); | |||
4119 | instrumentAsmArgument(Operand, I, IRB, DL, /*isOutput*/ false); | |||
4120 | } | |||
4121 | // Unpoison output arguments. This must happen before the actual InlineAsm | |||
4122 | // call, so that the shadow for memory published in the asm() statement | |||
4123 | // remains valid. | |||
4124 | for (int i = 0; i < OutputArgs; i++) { | |||
4125 | Value *Operand = CB->getOperand(i); | |||
4126 | instrumentAsmArgument(Operand, I, IRB, DL, /*isOutput*/ true); | |||
4127 | } | |||
4128 | ||||
4129 | setShadow(&I, getCleanShadow(&I)); | |||
4130 | setOrigin(&I, getCleanOrigin()); | |||
4131 | } | |||
4132 | ||||
4133 | void visitFreezeInst(FreezeInst &I) { | |||
4134 | // Freeze always returns a fully defined value. | |||
4135 | setShadow(&I, getCleanShadow(&I)); | |||
4136 | setOrigin(&I, getCleanOrigin()); | |||
4137 | } | |||
4138 | ||||
4139 | void visitInstruction(Instruction &I) { | |||
4140 | // Everything else: stop propagating and check for poisoned shadow. | |||
4141 | if (ClDumpStrictInstructions) | |||
4142 | dumpInst(I); | |||
4143 | LLVM_DEBUG(dbgs() << "DEFAULT: " << I << "\n")do { } while (false); | |||
4144 | for (size_t i = 0, n = I.getNumOperands(); i < n; i++) { | |||
4145 | Value *Operand = I.getOperand(i); | |||
4146 | if (Operand->getType()->isSized()) | |||
4147 | insertShadowCheck(Operand, &I); | |||
4148 | } | |||
4149 | setShadow(&I, getCleanShadow(&I)); | |||
4150 | setOrigin(&I, getCleanOrigin()); | |||
4151 | } | |||
4152 | }; | |||
4153 | ||||
4154 | /// AMD64-specific implementation of VarArgHelper. | |||
4155 | struct VarArgAMD64Helper : public VarArgHelper { | |||
4156 | // An unfortunate workaround for asymmetric lowering of va_arg stuff. | |||
4157 | // See a comment in visitCallBase for more details. | |||
4158 | static const unsigned AMD64GpEndOffset = 48; // AMD64 ABI Draft 0.99.6 p3.5.7 | |||
4159 | static const unsigned AMD64FpEndOffsetSSE = 176; | |||
4160 | // If SSE is disabled, fp_offset in va_list is zero. | |||
4161 | static const unsigned AMD64FpEndOffsetNoSSE = AMD64GpEndOffset; | |||
4162 | ||||
4163 | unsigned AMD64FpEndOffset; | |||
4164 | Function &F; | |||
4165 | MemorySanitizer &MS; | |||
4166 | MemorySanitizerVisitor &MSV; | |||
4167 | Value *VAArgTLSCopy = nullptr; | |||
4168 | Value *VAArgTLSOriginCopy = nullptr; | |||
4169 | Value *VAArgOverflowSize = nullptr; | |||
4170 | ||||
4171 | SmallVector<CallInst*, 16> VAStartInstrumentationList; | |||
4172 | ||||
4173 | enum ArgKind { AK_GeneralPurpose, AK_FloatingPoint, AK_Memory }; | |||
4174 | ||||
4175 | VarArgAMD64Helper(Function &F, MemorySanitizer &MS, | |||
4176 | MemorySanitizerVisitor &MSV) | |||
4177 | : F(F), MS(MS), MSV(MSV) { | |||
4178 | AMD64FpEndOffset = AMD64FpEndOffsetSSE; | |||
4179 | for (const auto &Attr : F.getAttributes().getFnAttributes()) { | |||
4180 | if (Attr.isStringAttribute() && | |||
4181 | (Attr.getKindAsString() == "target-features")) { | |||
4182 | if (Attr.getValueAsString().contains("-sse")) | |||
4183 | AMD64FpEndOffset = AMD64FpEndOffsetNoSSE; | |||
4184 | break; | |||
4185 | } | |||
4186 | } | |||
4187 | } | |||
4188 | ||||
4189 | ArgKind classifyArgument(Value* arg) { | |||
4190 | // A very rough approximation of X86_64 argument classification rules. | |||
4191 | Type *T = arg->getType(); | |||
4192 | if (T->isFPOrFPVectorTy() || T->isX86_MMXTy()) | |||
4193 | return AK_FloatingPoint; | |||
4194 | if (T->isIntegerTy() && T->getPrimitiveSizeInBits() <= 64) | |||
4195 | return AK_GeneralPurpose; | |||
4196 | if (T->isPointerTy()) | |||
4197 | return AK_GeneralPurpose; | |||
4198 | return AK_Memory; | |||
4199 | } | |||
4200 | ||||
4201 | // For VarArg functions, store the argument shadow in an ABI-specific format | |||
4202 | // that corresponds to va_list layout. | |||
4203 | // We do this because Clang lowers va_arg in the frontend, and this pass | |||
4204 | // only sees the low level code that deals with va_list internals. | |||
4205 | // A much easier alternative (provided that Clang emits va_arg instructions) | |||
4206 | // would have been to associate each live instance of va_list with a copy of | |||
4207 | // MSanParamTLS, and extract shadow on va_arg() call in the argument list | |||
4208 | // order. | |||
4209 | void visitCallBase(CallBase &CB, IRBuilder<> &IRB) override { | |||
4210 | unsigned GpOffset = 0; | |||
4211 | unsigned FpOffset = AMD64GpEndOffset; | |||
4212 | unsigned OverflowOffset = AMD64FpEndOffset; | |||
4213 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
4214 | for (auto ArgIt = CB.arg_begin(), End = CB.arg_end(); ArgIt != End; | |||
4215 | ++ArgIt) { | |||
4216 | Value *A = *ArgIt; | |||
4217 | unsigned ArgNo = CB.getArgOperandNo(ArgIt); | |||
4218 | bool IsFixed = ArgNo < CB.getFunctionType()->getNumParams(); | |||
4219 | bool IsByVal = CB.paramHasAttr(ArgNo, Attribute::ByVal); | |||
4220 | if (IsByVal) { | |||
4221 | // ByVal arguments always go to the overflow area. | |||
4222 | // Fixed arguments passed through the overflow area will be stepped | |||
4223 | // over by va_start, so don't count them towards the offset. | |||
4224 | if (IsFixed) | |||
4225 | continue; | |||
4226 | assert(A->getType()->isPointerTy())((void)0); | |||
4227 | Type *RealTy = CB.getParamByValType(ArgNo); | |||
4228 | uint64_t ArgSize = DL.getTypeAllocSize(RealTy); | |||
4229 | Value *ShadowBase = getShadowPtrForVAArgument( | |||
4230 | RealTy, IRB, OverflowOffset, alignTo(ArgSize, 8)); | |||
4231 | Value *OriginBase = nullptr; | |||
4232 | if (MS.TrackOrigins) | |||
4233 | OriginBase = getOriginPtrForVAArgument(RealTy, IRB, OverflowOffset); | |||
4234 | OverflowOffset += alignTo(ArgSize, 8); | |||
4235 | if (!ShadowBase) | |||
4236 | continue; | |||
4237 | Value *ShadowPtr, *OriginPtr; | |||
4238 | std::tie(ShadowPtr, OriginPtr) = | |||
4239 | MSV.getShadowOriginPtr(A, IRB, IRB.getInt8Ty(), kShadowTLSAlignment, | |||
4240 | /*isStore*/ false); | |||
4241 | ||||
4242 | IRB.CreateMemCpy(ShadowBase, kShadowTLSAlignment, ShadowPtr, | |||
4243 | kShadowTLSAlignment, ArgSize); | |||
4244 | if (MS.TrackOrigins) | |||
4245 | IRB.CreateMemCpy(OriginBase, kShadowTLSAlignment, OriginPtr, | |||
4246 | kShadowTLSAlignment, ArgSize); | |||
4247 | } else { | |||
4248 | ArgKind AK = classifyArgument(A); | |||
4249 | if (AK == AK_GeneralPurpose && GpOffset >= AMD64GpEndOffset) | |||
4250 | AK = AK_Memory; | |||
4251 | if (AK == AK_FloatingPoint && FpOffset >= AMD64FpEndOffset) | |||
4252 | AK = AK_Memory; | |||
4253 | Value *ShadowBase, *OriginBase = nullptr; | |||
4254 | switch (AK) { | |||
4255 | case AK_GeneralPurpose: | |||
4256 | ShadowBase = | |||
4257 | getShadowPtrForVAArgument(A->getType(), IRB, GpOffset, 8); | |||
4258 | if (MS.TrackOrigins) | |||
4259 | OriginBase = | |||
4260 | getOriginPtrForVAArgument(A->getType(), IRB, GpOffset); | |||
4261 | GpOffset += 8; | |||
4262 | break; | |||
4263 | case AK_FloatingPoint: | |||
4264 | ShadowBase = | |||
4265 | getShadowPtrForVAArgument(A->getType(), IRB, FpOffset, 16); | |||
4266 | if (MS.TrackOrigins) | |||
4267 | OriginBase = | |||
4268 | getOriginPtrForVAArgument(A->getType(), IRB, FpOffset); | |||
4269 | FpOffset += 16; | |||
4270 | break; | |||
4271 | case AK_Memory: | |||
4272 | if (IsFixed) | |||
4273 | continue; | |||
4274 | uint64_t ArgSize = DL.getTypeAllocSize(A->getType()); | |||
4275 | ShadowBase = | |||
4276 | getShadowPtrForVAArgument(A->getType(), IRB, OverflowOffset, 8); | |||
4277 | if (MS.TrackOrigins) | |||
4278 | OriginBase = | |||
4279 | getOriginPtrForVAArgument(A->getType(), IRB, OverflowOffset); | |||
4280 | OverflowOffset += alignTo(ArgSize, 8); | |||
4281 | } | |||
4282 | // Take fixed arguments into account for GpOffset and FpOffset, | |||
4283 | // but don't actually store shadows for them. | |||
4284 | // TODO(glider): don't call get*PtrForVAArgument() for them. | |||
4285 | if (IsFixed) | |||
4286 | continue; | |||
4287 | if (!ShadowBase) | |||
4288 | continue; | |||
4289 | Value *Shadow = MSV.getShadow(A); | |||
4290 | IRB.CreateAlignedStore(Shadow, ShadowBase, kShadowTLSAlignment); | |||
4291 | if (MS.TrackOrigins) { | |||
4292 | Value *Origin = MSV.getOrigin(A); | |||
4293 | unsigned StoreSize = DL.getTypeStoreSize(Shadow->getType()); | |||
4294 | MSV.paintOrigin(IRB, Origin, OriginBase, StoreSize, | |||
4295 | std::max(kShadowTLSAlignment, kMinOriginAlignment)); | |||
4296 | } | |||
4297 | } | |||
4298 | } | |||
4299 | Constant *OverflowSize = | |||
4300 | ConstantInt::get(IRB.getInt64Ty(), OverflowOffset - AMD64FpEndOffset); | |||
4301 | IRB.CreateStore(OverflowSize, MS.VAArgOverflowSizeTLS); | |||
4302 | } | |||
4303 | ||||
4304 | /// Compute the shadow address for a given va_arg. | |||
4305 | Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB, | |||
4306 | unsigned ArgOffset, unsigned ArgSize) { | |||
4307 | // Make sure we don't overflow __msan_va_arg_tls. | |||
4308 | if (ArgOffset + ArgSize > kParamTLSSize) | |||
4309 | return nullptr; | |||
4310 | Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy); | |||
4311 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
4312 | return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0), | |||
4313 | "_msarg_va_s"); | |||
4314 | } | |||
4315 | ||||
4316 | /// Compute the origin address for a given va_arg. | |||
4317 | Value *getOriginPtrForVAArgument(Type *Ty, IRBuilder<> &IRB, int ArgOffset) { | |||
4318 | Value *Base = IRB.CreatePointerCast(MS.VAArgOriginTLS, MS.IntptrTy); | |||
4319 | // getOriginPtrForVAArgument() is always called after | |||
4320 | // getShadowPtrForVAArgument(), so __msan_va_arg_origin_tls can never | |||
4321 | // overflow. | |||
4322 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
4323 | return IRB.CreateIntToPtr(Base, PointerType::get(MS.OriginTy, 0), | |||
4324 | "_msarg_va_o"); | |||
4325 | } | |||
4326 | ||||
4327 | void unpoisonVAListTagForInst(IntrinsicInst &I) { | |||
4328 | IRBuilder<> IRB(&I); | |||
4329 | Value *VAListTag = I.getArgOperand(0); | |||
4330 | Value *ShadowPtr, *OriginPtr; | |||
4331 | const Align Alignment = Align(8); | |||
4332 | std::tie(ShadowPtr, OriginPtr) = | |||
4333 | MSV.getShadowOriginPtr(VAListTag, IRB, IRB.getInt8Ty(), Alignment, | |||
4334 | /*isStore*/ true); | |||
4335 | ||||
4336 | // Unpoison the whole __va_list_tag. | |||
4337 | // FIXME: magic ABI constants. | |||
4338 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
4339 | /* size */ 24, Alignment, false); | |||
4340 | // We shouldn't need to zero out the origins, as they're only checked for | |||
4341 | // nonzero shadow. | |||
4342 | } | |||
4343 | ||||
4344 | void visitVAStartInst(VAStartInst &I) override { | |||
4345 | if (F.getCallingConv() == CallingConv::Win64) | |||
4346 | return; | |||
4347 | VAStartInstrumentationList.push_back(&I); | |||
4348 | unpoisonVAListTagForInst(I); | |||
4349 | } | |||
4350 | ||||
4351 | void visitVACopyInst(VACopyInst &I) override { | |||
4352 | if (F.getCallingConv() == CallingConv::Win64) return; | |||
4353 | unpoisonVAListTagForInst(I); | |||
4354 | } | |||
4355 | ||||
4356 | void finalizeInstrumentation() override { | |||
4357 | assert(!VAArgOverflowSize && !VAArgTLSCopy &&((void)0) | |||
4358 | "finalizeInstrumentation called twice")((void)0); | |||
4359 | if (!VAStartInstrumentationList.empty()) { | |||
4360 | // If there is a va_start in this function, make a backup copy of | |||
4361 | // va_arg_tls somewhere in the function entry block. | |||
4362 | IRBuilder<> IRB(MSV.FnPrologueEnd); | |||
4363 | VAArgOverflowSize = | |||
4364 | IRB.CreateLoad(IRB.getInt64Ty(), MS.VAArgOverflowSizeTLS); | |||
4365 | Value *CopySize = | |||
4366 | IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, AMD64FpEndOffset), | |||
4367 | VAArgOverflowSize); | |||
4368 | VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize); | |||
4369 | IRB.CreateMemCpy(VAArgTLSCopy, Align(8), MS.VAArgTLS, Align(8), CopySize); | |||
4370 | if (MS.TrackOrigins) { | |||
4371 | VAArgTLSOriginCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize); | |||
4372 | IRB.CreateMemCpy(VAArgTLSOriginCopy, Align(8), MS.VAArgOriginTLS, | |||
4373 | Align(8), CopySize); | |||
4374 | } | |||
4375 | } | |||
4376 | ||||
4377 | // Instrument va_start. | |||
4378 | // Copy va_list shadow from the backup copy of the TLS contents. | |||
4379 | for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) { | |||
4380 | CallInst *OrigInst = VAStartInstrumentationList[i]; | |||
4381 | IRBuilder<> IRB(OrigInst->getNextNode()); | |||
4382 | Value *VAListTag = OrigInst->getArgOperand(0); | |||
4383 | ||||
4384 | Type *RegSaveAreaPtrTy = Type::getInt64PtrTy(*MS.C); | |||
4385 | Value *RegSaveAreaPtrPtr = IRB.CreateIntToPtr( | |||
4386 | IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
4387 | ConstantInt::get(MS.IntptrTy, 16)), | |||
4388 | PointerType::get(RegSaveAreaPtrTy, 0)); | |||
4389 | Value *RegSaveAreaPtr = | |||
4390 | IRB.CreateLoad(RegSaveAreaPtrTy, RegSaveAreaPtrPtr); | |||
4391 | Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr; | |||
4392 | const Align Alignment = Align(16); | |||
4393 | std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) = | |||
4394 | MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(), | |||
4395 | Alignment, /*isStore*/ true); | |||
4396 | IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment, | |||
4397 | AMD64FpEndOffset); | |||
4398 | if (MS.TrackOrigins) | |||
4399 | IRB.CreateMemCpy(RegSaveAreaOriginPtr, Alignment, VAArgTLSOriginCopy, | |||
4400 | Alignment, AMD64FpEndOffset); | |||
4401 | Type *OverflowArgAreaPtrTy = Type::getInt64PtrTy(*MS.C); | |||
4402 | Value *OverflowArgAreaPtrPtr = IRB.CreateIntToPtr( | |||
4403 | IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
4404 | ConstantInt::get(MS.IntptrTy, 8)), | |||
4405 | PointerType::get(OverflowArgAreaPtrTy, 0)); | |||
4406 | Value *OverflowArgAreaPtr = | |||
4407 | IRB.CreateLoad(OverflowArgAreaPtrTy, OverflowArgAreaPtrPtr); | |||
4408 | Value *OverflowArgAreaShadowPtr, *OverflowArgAreaOriginPtr; | |||
4409 | std::tie(OverflowArgAreaShadowPtr, OverflowArgAreaOriginPtr) = | |||
4410 | MSV.getShadowOriginPtr(OverflowArgAreaPtr, IRB, IRB.getInt8Ty(), | |||
4411 | Alignment, /*isStore*/ true); | |||
4412 | Value *SrcPtr = IRB.CreateConstGEP1_32(IRB.getInt8Ty(), VAArgTLSCopy, | |||
4413 | AMD64FpEndOffset); | |||
4414 | IRB.CreateMemCpy(OverflowArgAreaShadowPtr, Alignment, SrcPtr, Alignment, | |||
4415 | VAArgOverflowSize); | |||
4416 | if (MS.TrackOrigins) { | |||
4417 | SrcPtr = IRB.CreateConstGEP1_32(IRB.getInt8Ty(), VAArgTLSOriginCopy, | |||
4418 | AMD64FpEndOffset); | |||
4419 | IRB.CreateMemCpy(OverflowArgAreaOriginPtr, Alignment, SrcPtr, Alignment, | |||
4420 | VAArgOverflowSize); | |||
4421 | } | |||
4422 | } | |||
4423 | } | |||
4424 | }; | |||
4425 | ||||
4426 | /// MIPS64-specific implementation of VarArgHelper. | |||
4427 | struct VarArgMIPS64Helper : public VarArgHelper { | |||
4428 | Function &F; | |||
4429 | MemorySanitizer &MS; | |||
4430 | MemorySanitizerVisitor &MSV; | |||
4431 | Value *VAArgTLSCopy = nullptr; | |||
4432 | Value *VAArgSize = nullptr; | |||
4433 | ||||
4434 | SmallVector<CallInst*, 16> VAStartInstrumentationList; | |||
4435 | ||||
4436 | VarArgMIPS64Helper(Function &F, MemorySanitizer &MS, | |||
4437 | MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {} | |||
4438 | ||||
4439 | void visitCallBase(CallBase &CB, IRBuilder<> &IRB) override { | |||
4440 | unsigned VAArgOffset = 0; | |||
4441 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
4442 | for (auto ArgIt = CB.arg_begin() + CB.getFunctionType()->getNumParams(), | |||
4443 | End = CB.arg_end(); | |||
4444 | ArgIt != End; ++ArgIt) { | |||
4445 | Triple TargetTriple(F.getParent()->getTargetTriple()); | |||
4446 | Value *A = *ArgIt; | |||
4447 | Value *Base; | |||
4448 | uint64_t ArgSize = DL.getTypeAllocSize(A->getType()); | |||
4449 | if (TargetTriple.getArch() == Triple::mips64) { | |||
4450 | // Adjusting the shadow for argument with size < 8 to match the placement | |||
4451 | // of bits in big endian system | |||
4452 | if (ArgSize < 8) | |||
4453 | VAArgOffset += (8 - ArgSize); | |||
4454 | } | |||
4455 | Base = getShadowPtrForVAArgument(A->getType(), IRB, VAArgOffset, ArgSize); | |||
4456 | VAArgOffset += ArgSize; | |||
4457 | VAArgOffset = alignTo(VAArgOffset, 8); | |||
4458 | if (!Base) | |||
4459 | continue; | |||
4460 | IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment); | |||
4461 | } | |||
4462 | ||||
4463 | Constant *TotalVAArgSize = ConstantInt::get(IRB.getInt64Ty(), VAArgOffset); | |||
4464 | // Here using VAArgOverflowSizeTLS as VAArgSizeTLS to avoid creation of | |||
4465 | // a new class member i.e. it is the total size of all VarArgs. | |||
4466 | IRB.CreateStore(TotalVAArgSize, MS.VAArgOverflowSizeTLS); | |||
4467 | } | |||
4468 | ||||
4469 | /// Compute the shadow address for a given va_arg. | |||
4470 | Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB, | |||
4471 | unsigned ArgOffset, unsigned ArgSize) { | |||
4472 | // Make sure we don't overflow __msan_va_arg_tls. | |||
4473 | if (ArgOffset + ArgSize > kParamTLSSize) | |||
4474 | return nullptr; | |||
4475 | Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy); | |||
4476 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
4477 | return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0), | |||
4478 | "_msarg"); | |||
4479 | } | |||
4480 | ||||
4481 | void visitVAStartInst(VAStartInst &I) override { | |||
4482 | IRBuilder<> IRB(&I); | |||
4483 | VAStartInstrumentationList.push_back(&I); | |||
4484 | Value *VAListTag = I.getArgOperand(0); | |||
4485 | Value *ShadowPtr, *OriginPtr; | |||
4486 | const Align Alignment = Align(8); | |||
4487 | std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr( | |||
4488 | VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true); | |||
4489 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
4490 | /* size */ 8, Alignment, false); | |||
4491 | } | |||
4492 | ||||
4493 | void visitVACopyInst(VACopyInst &I) override { | |||
4494 | IRBuilder<> IRB(&I); | |||
4495 | VAStartInstrumentationList.push_back(&I); | |||
4496 | Value *VAListTag = I.getArgOperand(0); | |||
4497 | Value *ShadowPtr, *OriginPtr; | |||
4498 | const Align Alignment = Align(8); | |||
4499 | std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr( | |||
4500 | VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true); | |||
4501 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
4502 | /* size */ 8, Alignment, false); | |||
4503 | } | |||
4504 | ||||
4505 | void finalizeInstrumentation() override { | |||
4506 | assert(!VAArgSize && !VAArgTLSCopy &&((void)0) | |||
4507 | "finalizeInstrumentation called twice")((void)0); | |||
4508 | IRBuilder<> IRB(MSV.FnPrologueEnd); | |||
4509 | VAArgSize = IRB.CreateLoad(IRB.getInt64Ty(), MS.VAArgOverflowSizeTLS); | |||
4510 | Value *CopySize = IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, 0), | |||
4511 | VAArgSize); | |||
4512 | ||||
4513 | if (!VAStartInstrumentationList.empty()) { | |||
4514 | // If there is a va_start in this function, make a backup copy of | |||
4515 | // va_arg_tls somewhere in the function entry block. | |||
4516 | VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize); | |||
4517 | IRB.CreateMemCpy(VAArgTLSCopy, Align(8), MS.VAArgTLS, Align(8), CopySize); | |||
4518 | } | |||
4519 | ||||
4520 | // Instrument va_start. | |||
4521 | // Copy va_list shadow from the backup copy of the TLS contents. | |||
4522 | for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) { | |||
4523 | CallInst *OrigInst = VAStartInstrumentationList[i]; | |||
4524 | IRBuilder<> IRB(OrigInst->getNextNode()); | |||
4525 | Value *VAListTag = OrigInst->getArgOperand(0); | |||
4526 | Type *RegSaveAreaPtrTy = Type::getInt64PtrTy(*MS.C); | |||
4527 | Value *RegSaveAreaPtrPtr = | |||
4528 | IRB.CreateIntToPtr(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
4529 | PointerType::get(RegSaveAreaPtrTy, 0)); | |||
4530 | Value *RegSaveAreaPtr = | |||
4531 | IRB.CreateLoad(RegSaveAreaPtrTy, RegSaveAreaPtrPtr); | |||
4532 | Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr; | |||
4533 | const Align Alignment = Align(8); | |||
4534 | std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) = | |||
4535 | MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(), | |||
4536 | Alignment, /*isStore*/ true); | |||
4537 | IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment, | |||
4538 | CopySize); | |||
4539 | } | |||
4540 | } | |||
4541 | }; | |||
4542 | ||||
4543 | /// AArch64-specific implementation of VarArgHelper. | |||
4544 | struct VarArgAArch64Helper : public VarArgHelper { | |||
4545 | static const unsigned kAArch64GrArgSize = 64; | |||
4546 | static const unsigned kAArch64VrArgSize = 128; | |||
4547 | ||||
4548 | static const unsigned AArch64GrBegOffset = 0; | |||
4549 | static const unsigned AArch64GrEndOffset = kAArch64GrArgSize; | |||
4550 | // Make VR space aligned to 16 bytes. | |||
4551 | static const unsigned AArch64VrBegOffset = AArch64GrEndOffset; | |||
4552 | static const unsigned AArch64VrEndOffset = AArch64VrBegOffset | |||
4553 | + kAArch64VrArgSize; | |||
4554 | static const unsigned AArch64VAEndOffset = AArch64VrEndOffset; | |||
4555 | ||||
4556 | Function &F; | |||
4557 | MemorySanitizer &MS; | |||
4558 | MemorySanitizerVisitor &MSV; | |||
4559 | Value *VAArgTLSCopy = nullptr; | |||
4560 | Value *VAArgOverflowSize = nullptr; | |||
4561 | ||||
4562 | SmallVector<CallInst*, 16> VAStartInstrumentationList; | |||
4563 | ||||
4564 | enum ArgKind { AK_GeneralPurpose, AK_FloatingPoint, AK_Memory }; | |||
4565 | ||||
4566 | VarArgAArch64Helper(Function &F, MemorySanitizer &MS, | |||
4567 | MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {} | |||
4568 | ||||
4569 | ArgKind classifyArgument(Value* arg) { | |||
4570 | Type *T = arg->getType(); | |||
4571 | if (T->isFPOrFPVectorTy()) | |||
4572 | return AK_FloatingPoint; | |||
4573 | if ((T->isIntegerTy() && T->getPrimitiveSizeInBits() <= 64) | |||
4574 | || (T->isPointerTy())) | |||
4575 | return AK_GeneralPurpose; | |||
4576 | return AK_Memory; | |||
4577 | } | |||
4578 | ||||
4579 | // The instrumentation stores the argument shadow in a non ABI-specific | |||
4580 | // format because it does not know which argument is named (since Clang, | |||
4581 | // like x86_64 case, lowers the va_args in the frontend and this pass only | |||
4582 | // sees the low level code that deals with va_list internals). | |||
4583 | // The first seven GR registers are saved in the first 56 bytes of the | |||
4584 | // va_arg tls arra, followers by the first 8 FP/SIMD registers, and then | |||
4585 | // the remaining arguments. | |||
4586 | // Using constant offset within the va_arg TLS array allows fast copy | |||
4587 | // in the finalize instrumentation. | |||
4588 | void visitCallBase(CallBase &CB, IRBuilder<> &IRB) override { | |||
4589 | unsigned GrOffset = AArch64GrBegOffset; | |||
4590 | unsigned VrOffset = AArch64VrBegOffset; | |||
4591 | unsigned OverflowOffset = AArch64VAEndOffset; | |||
4592 | ||||
4593 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
4594 | for (auto ArgIt = CB.arg_begin(), End = CB.arg_end(); ArgIt != End; | |||
4595 | ++ArgIt) { | |||
4596 | Value *A = *ArgIt; | |||
4597 | unsigned ArgNo = CB.getArgOperandNo(ArgIt); | |||
4598 | bool IsFixed = ArgNo < CB.getFunctionType()->getNumParams(); | |||
4599 | ArgKind AK = classifyArgument(A); | |||
4600 | if (AK == AK_GeneralPurpose && GrOffset >= AArch64GrEndOffset) | |||
4601 | AK = AK_Memory; | |||
4602 | if (AK == AK_FloatingPoint && VrOffset >= AArch64VrEndOffset) | |||
4603 | AK = AK_Memory; | |||
4604 | Value *Base; | |||
4605 | switch (AK) { | |||
4606 | case AK_GeneralPurpose: | |||
4607 | Base = getShadowPtrForVAArgument(A->getType(), IRB, GrOffset, 8); | |||
4608 | GrOffset += 8; | |||
4609 | break; | |||
4610 | case AK_FloatingPoint: | |||
4611 | Base = getShadowPtrForVAArgument(A->getType(), IRB, VrOffset, 8); | |||
4612 | VrOffset += 16; | |||
4613 | break; | |||
4614 | case AK_Memory: | |||
4615 | // Don't count fixed arguments in the overflow area - va_start will | |||
4616 | // skip right over them. | |||
4617 | if (IsFixed) | |||
4618 | continue; | |||
4619 | uint64_t ArgSize = DL.getTypeAllocSize(A->getType()); | |||
4620 | Base = getShadowPtrForVAArgument(A->getType(), IRB, OverflowOffset, | |||
4621 | alignTo(ArgSize, 8)); | |||
4622 | OverflowOffset += alignTo(ArgSize, 8); | |||
4623 | break; | |||
4624 | } | |||
4625 | // Count Gp/Vr fixed arguments to their respective offsets, but don't | |||
4626 | // bother to actually store a shadow. | |||
4627 | if (IsFixed) | |||
4628 | continue; | |||
4629 | if (!Base) | |||
4630 | continue; | |||
4631 | IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment); | |||
4632 | } | |||
4633 | Constant *OverflowSize = | |||
4634 | ConstantInt::get(IRB.getInt64Ty(), OverflowOffset - AArch64VAEndOffset); | |||
4635 | IRB.CreateStore(OverflowSize, MS.VAArgOverflowSizeTLS); | |||
4636 | } | |||
4637 | ||||
4638 | /// Compute the shadow address for a given va_arg. | |||
4639 | Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB, | |||
4640 | unsigned ArgOffset, unsigned ArgSize) { | |||
4641 | // Make sure we don't overflow __msan_va_arg_tls. | |||
4642 | if (ArgOffset + ArgSize > kParamTLSSize) | |||
4643 | return nullptr; | |||
4644 | Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy); | |||
4645 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
4646 | return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0), | |||
4647 | "_msarg"); | |||
4648 | } | |||
4649 | ||||
4650 | void visitVAStartInst(VAStartInst &I) override { | |||
4651 | IRBuilder<> IRB(&I); | |||
4652 | VAStartInstrumentationList.push_back(&I); | |||
4653 | Value *VAListTag = I.getArgOperand(0); | |||
4654 | Value *ShadowPtr, *OriginPtr; | |||
4655 | const Align Alignment = Align(8); | |||
4656 | std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr( | |||
4657 | VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true); | |||
4658 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
4659 | /* size */ 32, Alignment, false); | |||
4660 | } | |||
4661 | ||||
4662 | void visitVACopyInst(VACopyInst &I) override { | |||
4663 | IRBuilder<> IRB(&I); | |||
4664 | VAStartInstrumentationList.push_back(&I); | |||
4665 | Value *VAListTag = I.getArgOperand(0); | |||
4666 | Value *ShadowPtr, *OriginPtr; | |||
4667 | const Align Alignment = Align(8); | |||
4668 | std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr( | |||
4669 | VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true); | |||
4670 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
4671 | /* size */ 32, Alignment, false); | |||
4672 | } | |||
4673 | ||||
4674 | // Retrieve a va_list field of 'void*' size. | |||
4675 | Value* getVAField64(IRBuilder<> &IRB, Value *VAListTag, int offset) { | |||
4676 | Value *SaveAreaPtrPtr = | |||
4677 | IRB.CreateIntToPtr( | |||
4678 | IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
4679 | ConstantInt::get(MS.IntptrTy, offset)), | |||
4680 | Type::getInt64PtrTy(*MS.C)); | |||
4681 | return IRB.CreateLoad(Type::getInt64Ty(*MS.C), SaveAreaPtrPtr); | |||
4682 | } | |||
4683 | ||||
4684 | // Retrieve a va_list field of 'int' size. | |||
4685 | Value* getVAField32(IRBuilder<> &IRB, Value *VAListTag, int offset) { | |||
4686 | Value *SaveAreaPtr = | |||
4687 | IRB.CreateIntToPtr( | |||
4688 | IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
4689 | ConstantInt::get(MS.IntptrTy, offset)), | |||
4690 | Type::getInt32PtrTy(*MS.C)); | |||
4691 | Value *SaveArea32 = IRB.CreateLoad(IRB.getInt32Ty(), SaveAreaPtr); | |||
4692 | return IRB.CreateSExt(SaveArea32, MS.IntptrTy); | |||
4693 | } | |||
4694 | ||||
4695 | void finalizeInstrumentation() override { | |||
4696 | assert(!VAArgOverflowSize && !VAArgTLSCopy &&((void)0) | |||
4697 | "finalizeInstrumentation called twice")((void)0); | |||
4698 | if (!VAStartInstrumentationList.empty()) { | |||
4699 | // If there is a va_start in this function, make a backup copy of | |||
4700 | // va_arg_tls somewhere in the function entry block. | |||
4701 | IRBuilder<> IRB(MSV.FnPrologueEnd); | |||
4702 | VAArgOverflowSize = | |||
4703 | IRB.CreateLoad(IRB.getInt64Ty(), MS.VAArgOverflowSizeTLS); | |||
4704 | Value *CopySize = | |||
4705 | IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, AArch64VAEndOffset), | |||
4706 | VAArgOverflowSize); | |||
4707 | VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize); | |||
4708 | IRB.CreateMemCpy(VAArgTLSCopy, Align(8), MS.VAArgTLS, Align(8), CopySize); | |||
4709 | } | |||
4710 | ||||
4711 | Value *GrArgSize = ConstantInt::get(MS.IntptrTy, kAArch64GrArgSize); | |||
4712 | Value *VrArgSize = ConstantInt::get(MS.IntptrTy, kAArch64VrArgSize); | |||
4713 | ||||
4714 | // Instrument va_start, copy va_list shadow from the backup copy of | |||
4715 | // the TLS contents. | |||
4716 | for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) { | |||
4717 | CallInst *OrigInst = VAStartInstrumentationList[i]; | |||
4718 | IRBuilder<> IRB(OrigInst->getNextNode()); | |||
4719 | ||||
4720 | Value *VAListTag = OrigInst->getArgOperand(0); | |||
4721 | ||||
4722 | // The variadic ABI for AArch64 creates two areas to save the incoming | |||
4723 | // argument registers (one for 64-bit general register xn-x7 and another | |||
4724 | // for 128-bit FP/SIMD vn-v7). | |||
4725 | // We need then to propagate the shadow arguments on both regions | |||
4726 | // 'va::__gr_top + va::__gr_offs' and 'va::__vr_top + va::__vr_offs'. | |||
4727 | // The remaining arguments are saved on shadow for 'va::stack'. | |||
4728 | // One caveat is it requires only to propagate the non-named arguments, | |||
4729 | // however on the call site instrumentation 'all' the arguments are | |||
4730 | // saved. So to copy the shadow values from the va_arg TLS array | |||
4731 | // we need to adjust the offset for both GR and VR fields based on | |||
4732 | // the __{gr,vr}_offs value (since they are stores based on incoming | |||
4733 | // named arguments). | |||
4734 | ||||
4735 | // Read the stack pointer from the va_list. | |||
4736 | Value *StackSaveAreaPtr = getVAField64(IRB, VAListTag, 0); | |||
4737 | ||||
4738 | // Read both the __gr_top and __gr_off and add them up. | |||
4739 | Value *GrTopSaveAreaPtr = getVAField64(IRB, VAListTag, 8); | |||
4740 | Value *GrOffSaveArea = getVAField32(IRB, VAListTag, 24); | |||
4741 | ||||
4742 | Value *GrRegSaveAreaPtr = IRB.CreateAdd(GrTopSaveAreaPtr, GrOffSaveArea); | |||
4743 | ||||
4744 | // Read both the __vr_top and __vr_off and add them up. | |||
4745 | Value *VrTopSaveAreaPtr = getVAField64(IRB, VAListTag, 16); | |||
4746 | Value *VrOffSaveArea = getVAField32(IRB, VAListTag, 28); | |||
4747 | ||||
4748 | Value *VrRegSaveAreaPtr = IRB.CreateAdd(VrTopSaveAreaPtr, VrOffSaveArea); | |||
4749 | ||||
4750 | // It does not know how many named arguments is being used and, on the | |||
4751 | // callsite all the arguments were saved. Since __gr_off is defined as | |||
4752 | // '0 - ((8 - named_gr) * 8)', the idea is to just propagate the variadic | |||
4753 | // argument by ignoring the bytes of shadow from named arguments. | |||
4754 | Value *GrRegSaveAreaShadowPtrOff = | |||
4755 | IRB.CreateAdd(GrArgSize, GrOffSaveArea); | |||
4756 | ||||
4757 | Value *GrRegSaveAreaShadowPtr = | |||
4758 | MSV.getShadowOriginPtr(GrRegSaveAreaPtr, IRB, IRB.getInt8Ty(), | |||
4759 | Align(8), /*isStore*/ true) | |||
4760 | .first; | |||
4761 | ||||
4762 | Value *GrSrcPtr = IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy, | |||
4763 | GrRegSaveAreaShadowPtrOff); | |||
4764 | Value *GrCopySize = IRB.CreateSub(GrArgSize, GrRegSaveAreaShadowPtrOff); | |||
4765 | ||||
4766 | IRB.CreateMemCpy(GrRegSaveAreaShadowPtr, Align(8), GrSrcPtr, Align(8), | |||
4767 | GrCopySize); | |||
4768 | ||||
4769 | // Again, but for FP/SIMD values. | |||
4770 | Value *VrRegSaveAreaShadowPtrOff = | |||
4771 | IRB.CreateAdd(VrArgSize, VrOffSaveArea); | |||
4772 | ||||
4773 | Value *VrRegSaveAreaShadowPtr = | |||
4774 | MSV.getShadowOriginPtr(VrRegSaveAreaPtr, IRB, IRB.getInt8Ty(), | |||
4775 | Align(8), /*isStore*/ true) | |||
4776 | .first; | |||
4777 | ||||
4778 | Value *VrSrcPtr = IRB.CreateInBoundsGEP( | |||
4779 | IRB.getInt8Ty(), | |||
4780 | IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy, | |||
4781 | IRB.getInt32(AArch64VrBegOffset)), | |||
4782 | VrRegSaveAreaShadowPtrOff); | |||
4783 | Value *VrCopySize = IRB.CreateSub(VrArgSize, VrRegSaveAreaShadowPtrOff); | |||
4784 | ||||
4785 | IRB.CreateMemCpy(VrRegSaveAreaShadowPtr, Align(8), VrSrcPtr, Align(8), | |||
4786 | VrCopySize); | |||
4787 | ||||
4788 | // And finally for remaining arguments. | |||
4789 | Value *StackSaveAreaShadowPtr = | |||
4790 | MSV.getShadowOriginPtr(StackSaveAreaPtr, IRB, IRB.getInt8Ty(), | |||
4791 | Align(16), /*isStore*/ true) | |||
4792 | .first; | |||
4793 | ||||
4794 | Value *StackSrcPtr = | |||
4795 | IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy, | |||
4796 | IRB.getInt32(AArch64VAEndOffset)); | |||
4797 | ||||
4798 | IRB.CreateMemCpy(StackSaveAreaShadowPtr, Align(16), StackSrcPtr, | |||
4799 | Align(16), VAArgOverflowSize); | |||
4800 | } | |||
4801 | } | |||
4802 | }; | |||
4803 | ||||
4804 | /// PowerPC64-specific implementation of VarArgHelper. | |||
4805 | struct VarArgPowerPC64Helper : public VarArgHelper { | |||
4806 | Function &F; | |||
4807 | MemorySanitizer &MS; | |||
4808 | MemorySanitizerVisitor &MSV; | |||
4809 | Value *VAArgTLSCopy = nullptr; | |||
4810 | Value *VAArgSize = nullptr; | |||
4811 | ||||
4812 | SmallVector<CallInst*, 16> VAStartInstrumentationList; | |||
4813 | ||||
4814 | VarArgPowerPC64Helper(Function &F, MemorySanitizer &MS, | |||
4815 | MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {} | |||
4816 | ||||
4817 | void visitCallBase(CallBase &CB, IRBuilder<> &IRB) override { | |||
4818 | // For PowerPC, we need to deal with alignment of stack arguments - | |||
4819 | // they are mostly aligned to 8 bytes, but vectors and i128 arrays | |||
4820 | // are aligned to 16 bytes, byvals can be aligned to 8 or 16 bytes, | |||
4821 | // For that reason, we compute current offset from stack pointer (which is | |||
4822 | // always properly aligned), and offset for the first vararg, then subtract | |||
4823 | // them. | |||
4824 | unsigned VAArgBase; | |||
4825 | Triple TargetTriple(F.getParent()->getTargetTriple()); | |||
4826 | // Parameter save area starts at 48 bytes from frame pointer for ABIv1, | |||
4827 | // and 32 bytes for ABIv2. This is usually determined by target | |||
4828 | // endianness, but in theory could be overridden by function attribute. | |||
4829 | if (TargetTriple.getArch() == Triple::ppc64) | |||
4830 | VAArgBase = 48; | |||
4831 | else | |||
4832 | VAArgBase = 32; | |||
4833 | unsigned VAArgOffset = VAArgBase; | |||
4834 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
4835 | for (auto ArgIt = CB.arg_begin(), End = CB.arg_end(); ArgIt != End; | |||
4836 | ++ArgIt) { | |||
4837 | Value *A = *ArgIt; | |||
4838 | unsigned ArgNo = CB.getArgOperandNo(ArgIt); | |||
4839 | bool IsFixed = ArgNo < CB.getFunctionType()->getNumParams(); | |||
4840 | bool IsByVal = CB.paramHasAttr(ArgNo, Attribute::ByVal); | |||
4841 | if (IsByVal) { | |||
4842 | assert(A->getType()->isPointerTy())((void)0); | |||
4843 | Type *RealTy = CB.getParamByValType(ArgNo); | |||
4844 | uint64_t ArgSize = DL.getTypeAllocSize(RealTy); | |||
4845 | MaybeAlign ArgAlign = CB.getParamAlign(ArgNo); | |||
4846 | if (!ArgAlign || *ArgAlign < Align(8)) | |||
4847 | ArgAlign = Align(8); | |||
4848 | VAArgOffset = alignTo(VAArgOffset, ArgAlign); | |||
4849 | if (!IsFixed) { | |||
4850 | Value *Base = getShadowPtrForVAArgument( | |||
4851 | RealTy, IRB, VAArgOffset - VAArgBase, ArgSize); | |||
4852 | if (Base) { | |||
4853 | Value *AShadowPtr, *AOriginPtr; | |||
4854 | std::tie(AShadowPtr, AOriginPtr) = | |||
4855 | MSV.getShadowOriginPtr(A, IRB, IRB.getInt8Ty(), | |||
4856 | kShadowTLSAlignment, /*isStore*/ false); | |||
4857 | ||||
4858 | IRB.CreateMemCpy(Base, kShadowTLSAlignment, AShadowPtr, | |||
4859 | kShadowTLSAlignment, ArgSize); | |||
4860 | } | |||
4861 | } | |||
4862 | VAArgOffset += alignTo(ArgSize, 8); | |||
4863 | } else { | |||
4864 | Value *Base; | |||
4865 | uint64_t ArgSize = DL.getTypeAllocSize(A->getType()); | |||
4866 | uint64_t ArgAlign = 8; | |||
4867 | if (A->getType()->isArrayTy()) { | |||
4868 | // Arrays are aligned to element size, except for long double | |||
4869 | // arrays, which are aligned to 8 bytes. | |||
4870 | Type *ElementTy = A->getType()->getArrayElementType(); | |||
4871 | if (!ElementTy->isPPC_FP128Ty()) | |||
4872 | ArgAlign = DL.getTypeAllocSize(ElementTy); | |||
4873 | } else if (A->getType()->isVectorTy()) { | |||
4874 | // Vectors are naturally aligned. | |||
4875 | ArgAlign = DL.getTypeAllocSize(A->getType()); | |||
4876 | } | |||
4877 | if (ArgAlign < 8) | |||
4878 | ArgAlign = 8; | |||
4879 | VAArgOffset = alignTo(VAArgOffset, ArgAlign); | |||
4880 | if (DL.isBigEndian()) { | |||
4881 | // Adjusting the shadow for argument with size < 8 to match the placement | |||
4882 | // of bits in big endian system | |||
4883 | if (ArgSize < 8) | |||
4884 | VAArgOffset += (8 - ArgSize); | |||
4885 | } | |||
4886 | if (!IsFixed) { | |||
4887 | Base = getShadowPtrForVAArgument(A->getType(), IRB, | |||
4888 | VAArgOffset - VAArgBase, ArgSize); | |||
4889 | if (Base) | |||
4890 | IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment); | |||
4891 | } | |||
4892 | VAArgOffset += ArgSize; | |||
4893 | VAArgOffset = alignTo(VAArgOffset, 8); | |||
4894 | } | |||
4895 | if (IsFixed) | |||
4896 | VAArgBase = VAArgOffset; | |||
4897 | } | |||
4898 | ||||
4899 | Constant *TotalVAArgSize = ConstantInt::get(IRB.getInt64Ty(), | |||
4900 | VAArgOffset - VAArgBase); | |||
4901 | // Here using VAArgOverflowSizeTLS as VAArgSizeTLS to avoid creation of | |||
4902 | // a new class member i.e. it is the total size of all VarArgs. | |||
4903 | IRB.CreateStore(TotalVAArgSize, MS.VAArgOverflowSizeTLS); | |||
4904 | } | |||
4905 | ||||
4906 | /// Compute the shadow address for a given va_arg. | |||
4907 | Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB, | |||
4908 | unsigned ArgOffset, unsigned ArgSize) { | |||
4909 | // Make sure we don't overflow __msan_va_arg_tls. | |||
4910 | if (ArgOffset + ArgSize > kParamTLSSize) | |||
4911 | return nullptr; | |||
4912 | Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy); | |||
4913 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
4914 | return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0), | |||
4915 | "_msarg"); | |||
4916 | } | |||
4917 | ||||
4918 | void visitVAStartInst(VAStartInst &I) override { | |||
4919 | IRBuilder<> IRB(&I); | |||
4920 | VAStartInstrumentationList.push_back(&I); | |||
4921 | Value *VAListTag = I.getArgOperand(0); | |||
4922 | Value *ShadowPtr, *OriginPtr; | |||
4923 | const Align Alignment = Align(8); | |||
4924 | std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr( | |||
4925 | VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true); | |||
4926 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
4927 | /* size */ 8, Alignment, false); | |||
4928 | } | |||
4929 | ||||
4930 | void visitVACopyInst(VACopyInst &I) override { | |||
4931 | IRBuilder<> IRB(&I); | |||
4932 | Value *VAListTag = I.getArgOperand(0); | |||
4933 | Value *ShadowPtr, *OriginPtr; | |||
4934 | const Align Alignment = Align(8); | |||
4935 | std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr( | |||
4936 | VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true); | |||
4937 | // Unpoison the whole __va_list_tag. | |||
4938 | // FIXME: magic ABI constants. | |||
4939 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
4940 | /* size */ 8, Alignment, false); | |||
4941 | } | |||
4942 | ||||
4943 | void finalizeInstrumentation() override { | |||
4944 | assert(!VAArgSize && !VAArgTLSCopy &&((void)0) | |||
4945 | "finalizeInstrumentation called twice")((void)0); | |||
4946 | IRBuilder<> IRB(MSV.FnPrologueEnd); | |||
4947 | VAArgSize = IRB.CreateLoad(IRB.getInt64Ty(), MS.VAArgOverflowSizeTLS); | |||
4948 | Value *CopySize = IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, 0), | |||
4949 | VAArgSize); | |||
4950 | ||||
4951 | if (!VAStartInstrumentationList.empty()) { | |||
4952 | // If there is a va_start in this function, make a backup copy of | |||
4953 | // va_arg_tls somewhere in the function entry block. | |||
4954 | VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize); | |||
4955 | IRB.CreateMemCpy(VAArgTLSCopy, Align(8), MS.VAArgTLS, Align(8), CopySize); | |||
4956 | } | |||
4957 | ||||
4958 | // Instrument va_start. | |||
4959 | // Copy va_list shadow from the backup copy of the TLS contents. | |||
4960 | for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) { | |||
4961 | CallInst *OrigInst = VAStartInstrumentationList[i]; | |||
4962 | IRBuilder<> IRB(OrigInst->getNextNode()); | |||
4963 | Value *VAListTag = OrigInst->getArgOperand(0); | |||
4964 | Type *RegSaveAreaPtrTy = Type::getInt64PtrTy(*MS.C); | |||
4965 | Value *RegSaveAreaPtrPtr = | |||
4966 | IRB.CreateIntToPtr(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
4967 | PointerType::get(RegSaveAreaPtrTy, 0)); | |||
4968 | Value *RegSaveAreaPtr = | |||
4969 | IRB.CreateLoad(RegSaveAreaPtrTy, RegSaveAreaPtrPtr); | |||
4970 | Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr; | |||
4971 | const Align Alignment = Align(8); | |||
4972 | std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) = | |||
4973 | MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(), | |||
4974 | Alignment, /*isStore*/ true); | |||
4975 | IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment, | |||
4976 | CopySize); | |||
4977 | } | |||
4978 | } | |||
4979 | }; | |||
4980 | ||||
4981 | /// SystemZ-specific implementation of VarArgHelper. | |||
4982 | struct VarArgSystemZHelper : public VarArgHelper { | |||
4983 | static const unsigned SystemZGpOffset = 16; | |||
4984 | static const unsigned SystemZGpEndOffset = 56; | |||
4985 | static const unsigned SystemZFpOffset = 128; | |||
4986 | static const unsigned SystemZFpEndOffset = 160; | |||
4987 | static const unsigned SystemZMaxVrArgs = 8; | |||
4988 | static const unsigned SystemZRegSaveAreaSize = 160; | |||
4989 | static const unsigned SystemZOverflowOffset = 160; | |||
4990 | static const unsigned SystemZVAListTagSize = 32; | |||
4991 | static const unsigned SystemZOverflowArgAreaPtrOffset = 16; | |||
4992 | static const unsigned SystemZRegSaveAreaPtrOffset = 24; | |||
4993 | ||||
4994 | Function &F; | |||
4995 | MemorySanitizer &MS; | |||
4996 | MemorySanitizerVisitor &MSV; | |||
4997 | Value *VAArgTLSCopy = nullptr; | |||
4998 | Value *VAArgTLSOriginCopy = nullptr; | |||
4999 | Value *VAArgOverflowSize = nullptr; | |||
5000 | ||||
5001 | SmallVector<CallInst *, 16> VAStartInstrumentationList; | |||
5002 | ||||
5003 | enum class ArgKind { | |||
5004 | GeneralPurpose, | |||
5005 | FloatingPoint, | |||
5006 | Vector, | |||
5007 | Memory, | |||
5008 | Indirect, | |||
5009 | }; | |||
5010 | ||||
5011 | enum class ShadowExtension { None, Zero, Sign }; | |||
5012 | ||||
5013 | VarArgSystemZHelper(Function &F, MemorySanitizer &MS, | |||
5014 | MemorySanitizerVisitor &MSV) | |||
5015 | : F(F), MS(MS), MSV(MSV) {} | |||
5016 | ||||
5017 | ArgKind classifyArgument(Type *T, bool IsSoftFloatABI) { | |||
5018 | // T is a SystemZABIInfo::classifyArgumentType() output, and there are | |||
5019 | // only a few possibilities of what it can be. In particular, enums, single | |||
5020 | // element structs and large types have already been taken care of. | |||
5021 | ||||
5022 | // Some i128 and fp128 arguments are converted to pointers only in the | |||
5023 | // back end. | |||
5024 | if (T->isIntegerTy(128) || T->isFP128Ty()) | |||
5025 | return ArgKind::Indirect; | |||
5026 | if (T->isFloatingPointTy()) | |||
5027 | return IsSoftFloatABI ? ArgKind::GeneralPurpose : ArgKind::FloatingPoint; | |||
5028 | if (T->isIntegerTy() || T->isPointerTy()) | |||
5029 | return ArgKind::GeneralPurpose; | |||
5030 | if (T->isVectorTy()) | |||
5031 | return ArgKind::Vector; | |||
5032 | return ArgKind::Memory; | |||
5033 | } | |||
5034 | ||||
5035 | ShadowExtension getShadowExtension(const CallBase &CB, unsigned ArgNo) { | |||
5036 | // ABI says: "One of the simple integer types no more than 64 bits wide. | |||
5037 | // ... If such an argument is shorter than 64 bits, replace it by a full | |||
5038 | // 64-bit integer representing the same number, using sign or zero | |||
5039 | // extension". Shadow for an integer argument has the same type as the | |||
5040 | // argument itself, so it can be sign or zero extended as well. | |||
5041 | bool ZExt = CB.paramHasAttr(ArgNo, Attribute::ZExt); | |||
5042 | bool SExt = CB.paramHasAttr(ArgNo, Attribute::SExt); | |||
5043 | if (ZExt) { | |||
5044 | assert(!SExt)((void)0); | |||
5045 | return ShadowExtension::Zero; | |||
5046 | } | |||
5047 | if (SExt) { | |||
5048 | assert(!ZExt)((void)0); | |||
5049 | return ShadowExtension::Sign; | |||
5050 | } | |||
5051 | return ShadowExtension::None; | |||
5052 | } | |||
5053 | ||||
5054 | void visitCallBase(CallBase &CB, IRBuilder<> &IRB) override { | |||
5055 | bool IsSoftFloatABI = CB.getCalledFunction() | |||
5056 | ->getFnAttribute("use-soft-float") | |||
5057 | .getValueAsBool(); | |||
5058 | unsigned GpOffset = SystemZGpOffset; | |||
5059 | unsigned FpOffset = SystemZFpOffset; | |||
5060 | unsigned VrIndex = 0; | |||
5061 | unsigned OverflowOffset = SystemZOverflowOffset; | |||
5062 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
5063 | for (auto ArgIt = CB.arg_begin(), End = CB.arg_end(); ArgIt != End; | |||
5064 | ++ArgIt) { | |||
5065 | Value *A = *ArgIt; | |||
5066 | unsigned ArgNo = CB.getArgOperandNo(ArgIt); | |||
5067 | bool IsFixed = ArgNo < CB.getFunctionType()->getNumParams(); | |||
5068 | // SystemZABIInfo does not produce ByVal parameters. | |||
5069 | assert(!CB.paramHasAttr(ArgNo, Attribute::ByVal))((void)0); | |||
5070 | Type *T = A->getType(); | |||
5071 | ArgKind AK = classifyArgument(T, IsSoftFloatABI); | |||
5072 | if (AK == ArgKind::Indirect) { | |||
5073 | T = PointerType::get(T, 0); | |||
5074 | AK = ArgKind::GeneralPurpose; | |||
5075 | } | |||
5076 | if (AK == ArgKind::GeneralPurpose && GpOffset >= SystemZGpEndOffset) | |||
5077 | AK = ArgKind::Memory; | |||
5078 | if (AK == ArgKind::FloatingPoint && FpOffset >= SystemZFpEndOffset) | |||
5079 | AK = ArgKind::Memory; | |||
5080 | if (AK == ArgKind::Vector && (VrIndex >= SystemZMaxVrArgs || !IsFixed)) | |||
5081 | AK = ArgKind::Memory; | |||
5082 | Value *ShadowBase = nullptr; | |||
5083 | Value *OriginBase = nullptr; | |||
5084 | ShadowExtension SE = ShadowExtension::None; | |||
5085 | switch (AK) { | |||
5086 | case ArgKind::GeneralPurpose: { | |||
5087 | // Always keep track of GpOffset, but store shadow only for varargs. | |||
5088 | uint64_t ArgSize = 8; | |||
5089 | if (GpOffset + ArgSize <= kParamTLSSize) { | |||
5090 | if (!IsFixed) { | |||
5091 | SE = getShadowExtension(CB, ArgNo); | |||
5092 | uint64_t GapSize = 0; | |||
5093 | if (SE == ShadowExtension::None) { | |||
5094 | uint64_t ArgAllocSize = DL.getTypeAllocSize(T); | |||
5095 | assert(ArgAllocSize <= ArgSize)((void)0); | |||
5096 | GapSize = ArgSize - ArgAllocSize; | |||
5097 | } | |||
5098 | ShadowBase = getShadowAddrForVAArgument(IRB, GpOffset + GapSize); | |||
5099 | if (MS.TrackOrigins) | |||
5100 | OriginBase = getOriginPtrForVAArgument(IRB, GpOffset + GapSize); | |||
5101 | } | |||
5102 | GpOffset += ArgSize; | |||
5103 | } else { | |||
5104 | GpOffset = kParamTLSSize; | |||
5105 | } | |||
5106 | break; | |||
5107 | } | |||
5108 | case ArgKind::FloatingPoint: { | |||
5109 | // Always keep track of FpOffset, but store shadow only for varargs. | |||
5110 | uint64_t ArgSize = 8; | |||
5111 | if (FpOffset + ArgSize <= kParamTLSSize) { | |||
5112 | if (!IsFixed) { | |||
5113 | // PoP says: "A short floating-point datum requires only the | |||
5114 | // left-most 32 bit positions of a floating-point register". | |||
5115 | // Therefore, in contrast to AK_GeneralPurpose and AK_Memory, | |||
5116 | // don't extend shadow and don't mind the gap. | |||
5117 | ShadowBase = getShadowAddrForVAArgument(IRB, FpOffset); | |||
5118 | if (MS.TrackOrigins) | |||
5119 | OriginBase = getOriginPtrForVAArgument(IRB, FpOffset); | |||
5120 | } | |||
5121 | FpOffset += ArgSize; | |||
5122 | } else { | |||
5123 | FpOffset = kParamTLSSize; | |||
5124 | } | |||
5125 | break; | |||
5126 | } | |||
5127 | case ArgKind::Vector: { | |||
5128 | // Keep track of VrIndex. No need to store shadow, since vector varargs | |||
5129 | // go through AK_Memory. | |||
5130 | assert(IsFixed)((void)0); | |||
5131 | VrIndex++; | |||
5132 | break; | |||
5133 | } | |||
5134 | case ArgKind::Memory: { | |||
5135 | // Keep track of OverflowOffset and store shadow only for varargs. | |||
5136 | // Ignore fixed args, since we need to copy only the vararg portion of | |||
5137 | // the overflow area shadow. | |||
5138 | if (!IsFixed) { | |||
5139 | uint64_t ArgAllocSize = DL.getTypeAllocSize(T); | |||
5140 | uint64_t ArgSize = alignTo(ArgAllocSize, 8); | |||
5141 | if (OverflowOffset + ArgSize <= kParamTLSSize) { | |||
5142 | SE = getShadowExtension(CB, ArgNo); | |||
5143 | uint64_t GapSize = | |||
5144 | SE == ShadowExtension::None ? ArgSize - ArgAllocSize : 0; | |||
5145 | ShadowBase = | |||
5146 | getShadowAddrForVAArgument(IRB, OverflowOffset + GapSize); | |||
5147 | if (MS.TrackOrigins) | |||
5148 | OriginBase = | |||
5149 | getOriginPtrForVAArgument(IRB, OverflowOffset + GapSize); | |||
5150 | OverflowOffset += ArgSize; | |||
5151 | } else { | |||
5152 | OverflowOffset = kParamTLSSize; | |||
5153 | } | |||
5154 | } | |||
5155 | break; | |||
5156 | } | |||
5157 | case ArgKind::Indirect: | |||
5158 | llvm_unreachable("Indirect must be converted to GeneralPurpose")__builtin_unreachable(); | |||
5159 | } | |||
5160 | if (ShadowBase == nullptr) | |||
5161 | continue; | |||
5162 | Value *Shadow = MSV.getShadow(A); | |||
5163 | if (SE != ShadowExtension::None) | |||
5164 | Shadow = MSV.CreateShadowCast(IRB, Shadow, IRB.getInt64Ty(), | |||
5165 | /*Signed*/ SE == ShadowExtension::Sign); | |||
5166 | ShadowBase = IRB.CreateIntToPtr( | |||
5167 | ShadowBase, PointerType::get(Shadow->getType(), 0), "_msarg_va_s"); | |||
5168 | IRB.CreateStore(Shadow, ShadowBase); | |||
5169 | if (MS.TrackOrigins) { | |||
5170 | Value *Origin = MSV.getOrigin(A); | |||
5171 | unsigned StoreSize = DL.getTypeStoreSize(Shadow->getType()); | |||
5172 | MSV.paintOrigin(IRB, Origin, OriginBase, StoreSize, | |||
5173 | kMinOriginAlignment); | |||
5174 | } | |||
5175 | } | |||
5176 | Constant *OverflowSize = ConstantInt::get( | |||
5177 | IRB.getInt64Ty(), OverflowOffset - SystemZOverflowOffset); | |||
5178 | IRB.CreateStore(OverflowSize, MS.VAArgOverflowSizeTLS); | |||
5179 | } | |||
5180 | ||||
5181 | Value *getShadowAddrForVAArgument(IRBuilder<> &IRB, unsigned ArgOffset) { | |||
5182 | Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy); | |||
5183 | return IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
5184 | } | |||
5185 | ||||
5186 | Value *getOriginPtrForVAArgument(IRBuilder<> &IRB, int ArgOffset) { | |||
5187 | Value *Base = IRB.CreatePointerCast(MS.VAArgOriginTLS, MS.IntptrTy); | |||
5188 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
5189 | return IRB.CreateIntToPtr(Base, PointerType::get(MS.OriginTy, 0), | |||
5190 | "_msarg_va_o"); | |||
5191 | } | |||
5192 | ||||
5193 | void unpoisonVAListTagForInst(IntrinsicInst &I) { | |||
5194 | IRBuilder<> IRB(&I); | |||
5195 | Value *VAListTag = I.getArgOperand(0); | |||
5196 | Value *ShadowPtr, *OriginPtr; | |||
5197 | const Align Alignment = Align(8); | |||
5198 | std::tie(ShadowPtr, OriginPtr) = | |||
5199 | MSV.getShadowOriginPtr(VAListTag, IRB, IRB.getInt8Ty(), Alignment, | |||
5200 | /*isStore*/ true); | |||
5201 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
5202 | SystemZVAListTagSize, Alignment, false); | |||
5203 | } | |||
5204 | ||||
5205 | void visitVAStartInst(VAStartInst &I) override { | |||
5206 | VAStartInstrumentationList.push_back(&I); | |||
5207 | unpoisonVAListTagForInst(I); | |||
5208 | } | |||
5209 | ||||
5210 | void visitVACopyInst(VACopyInst &I) override { unpoisonVAListTagForInst(I); } | |||
5211 | ||||
5212 | void copyRegSaveArea(IRBuilder<> &IRB, Value *VAListTag) { | |||
5213 | Type *RegSaveAreaPtrTy = Type::getInt64PtrTy(*MS.C); | |||
5214 | Value *RegSaveAreaPtrPtr = IRB.CreateIntToPtr( | |||
5215 | IRB.CreateAdd( | |||
5216 | IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
5217 | ConstantInt::get(MS.IntptrTy, SystemZRegSaveAreaPtrOffset)), | |||
5218 | PointerType::get(RegSaveAreaPtrTy, 0)); | |||
5219 | Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrTy, RegSaveAreaPtrPtr); | |||
5220 | Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr; | |||
5221 | const Align Alignment = Align(8); | |||
5222 | std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) = | |||
5223 | MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(), Alignment, | |||
5224 | /*isStore*/ true); | |||
5225 | // TODO(iii): copy only fragments filled by visitCallBase() | |||
5226 | IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment, | |||
5227 | SystemZRegSaveAreaSize); | |||
5228 | if (MS.TrackOrigins) | |||
5229 | IRB.CreateMemCpy(RegSaveAreaOriginPtr, Alignment, VAArgTLSOriginCopy, | |||
5230 | Alignment, SystemZRegSaveAreaSize); | |||
5231 | } | |||
5232 | ||||
5233 | void copyOverflowArea(IRBuilder<> &IRB, Value *VAListTag) { | |||
5234 | Type *OverflowArgAreaPtrTy = Type::getInt64PtrTy(*MS.C); | |||
5235 | Value *OverflowArgAreaPtrPtr = IRB.CreateIntToPtr( | |||
5236 | IRB.CreateAdd( | |||
5237 | IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
5238 | ConstantInt::get(MS.IntptrTy, SystemZOverflowArgAreaPtrOffset)), | |||
5239 | PointerType::get(OverflowArgAreaPtrTy, 0)); | |||
5240 | Value *OverflowArgAreaPtr = | |||
5241 | IRB.CreateLoad(OverflowArgAreaPtrTy, OverflowArgAreaPtrPtr); | |||
5242 | Value *OverflowArgAreaShadowPtr, *OverflowArgAreaOriginPtr; | |||
5243 | const Align Alignment = Align(8); | |||
5244 | std::tie(OverflowArgAreaShadowPtr, OverflowArgAreaOriginPtr) = | |||
5245 | MSV.getShadowOriginPtr(OverflowArgAreaPtr, IRB, IRB.getInt8Ty(), | |||
5246 | Alignment, /*isStore*/ true); | |||
5247 | Value *SrcPtr = IRB.CreateConstGEP1_32(IRB.getInt8Ty(), VAArgTLSCopy, | |||
5248 | SystemZOverflowOffset); | |||
5249 | IRB.CreateMemCpy(OverflowArgAreaShadowPtr, Alignment, SrcPtr, Alignment, | |||
5250 | VAArgOverflowSize); | |||
5251 | if (MS.TrackOrigins) { | |||
5252 | SrcPtr = IRB.CreateConstGEP1_32(IRB.getInt8Ty(), VAArgTLSOriginCopy, | |||
5253 | SystemZOverflowOffset); | |||
5254 | IRB.CreateMemCpy(OverflowArgAreaOriginPtr, Alignment, SrcPtr, Alignment, | |||
5255 | VAArgOverflowSize); | |||
5256 | } | |||
5257 | } | |||
5258 | ||||
5259 | void finalizeInstrumentation() override { | |||
5260 | assert(!VAArgOverflowSize && !VAArgTLSCopy &&((void)0) | |||
5261 | "finalizeInstrumentation called twice")((void)0); | |||
5262 | if (!VAStartInstrumentationList.empty()) { | |||
5263 | // If there is a va_start in this function, make a backup copy of | |||
5264 | // va_arg_tls somewhere in the function entry block. | |||
5265 | IRBuilder<> IRB(MSV.FnPrologueEnd); | |||
5266 | VAArgOverflowSize = | |||
5267 | IRB.CreateLoad(IRB.getInt64Ty(), MS.VAArgOverflowSizeTLS); | |||
5268 | Value *CopySize = | |||
5269 | IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, SystemZOverflowOffset), | |||
5270 | VAArgOverflowSize); | |||
5271 | VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize); | |||
5272 | IRB.CreateMemCpy(VAArgTLSCopy, Align(8), MS.VAArgTLS, Align(8), CopySize); | |||
5273 | if (MS.TrackOrigins) { | |||
5274 | VAArgTLSOriginCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize); | |||
5275 | IRB.CreateMemCpy(VAArgTLSOriginCopy, Align(8), MS.VAArgOriginTLS, | |||
5276 | Align(8), CopySize); | |||
5277 | } | |||
5278 | } | |||
5279 | ||||
5280 | // Instrument va_start. | |||
5281 | // Copy va_list shadow from the backup copy of the TLS contents. | |||
5282 | for (size_t VaStartNo = 0, VaStartNum = VAStartInstrumentationList.size(); | |||
5283 | VaStartNo < VaStartNum; VaStartNo++) { | |||
5284 | CallInst *OrigInst = VAStartInstrumentationList[VaStartNo]; | |||
5285 | IRBuilder<> IRB(OrigInst->getNextNode()); | |||
5286 | Value *VAListTag = OrigInst->getArgOperand(0); | |||
5287 | copyRegSaveArea(IRB, VAListTag); | |||
5288 | copyOverflowArea(IRB, VAListTag); | |||
5289 | } | |||
5290 | } | |||
5291 | }; | |||
5292 | ||||
5293 | /// A no-op implementation of VarArgHelper. | |||
5294 | struct VarArgNoOpHelper : public VarArgHelper { | |||
5295 | VarArgNoOpHelper(Function &F, MemorySanitizer &MS, | |||
5296 | MemorySanitizerVisitor &MSV) {} | |||
5297 | ||||
5298 | void visitCallBase(CallBase &CB, IRBuilder<> &IRB) override {} | |||
5299 | ||||
5300 | void visitVAStartInst(VAStartInst &I) override {} | |||
5301 | ||||
5302 | void visitVACopyInst(VACopyInst &I) override {} | |||
5303 | ||||
5304 | void finalizeInstrumentation() override {} | |||
5305 | }; | |||
5306 | ||||
5307 | } // end anonymous namespace | |||
5308 | ||||
5309 | static VarArgHelper *CreateVarArgHelper(Function &Func, MemorySanitizer &Msan, | |||
5310 | MemorySanitizerVisitor &Visitor) { | |||
5311 | // VarArg handling is only implemented on AMD64. False positives are possible | |||
5312 | // on other platforms. | |||
5313 | Triple TargetTriple(Func.getParent()->getTargetTriple()); | |||
5314 | if (TargetTriple.getArch() == Triple::x86_64) | |||
5315 | return new VarArgAMD64Helper(Func, Msan, Visitor); | |||
5316 | else if (TargetTriple.isMIPS64()) | |||
5317 | return new VarArgMIPS64Helper(Func, Msan, Visitor); | |||
5318 | else if (TargetTriple.getArch() == Triple::aarch64) | |||
5319 | return new VarArgAArch64Helper(Func, Msan, Visitor); | |||
5320 | else if (TargetTriple.getArch() == Triple::ppc64 || | |||
5321 | TargetTriple.getArch() == Triple::ppc64le) | |||
5322 | return new VarArgPowerPC64Helper(Func, Msan, Visitor); | |||
5323 | else if (TargetTriple.getArch() == Triple::systemz) | |||
5324 | return new VarArgSystemZHelper(Func, Msan, Visitor); | |||
5325 | else | |||
5326 | return new VarArgNoOpHelper(Func, Msan, Visitor); | |||
5327 | } | |||
5328 | ||||
5329 | bool MemorySanitizer::sanitizeFunction(Function &F, TargetLibraryInfo &TLI) { | |||
5330 | if (!CompileKernel && F.getName() == kMsanModuleCtorName) | |||
5331 | return false; | |||
5332 | ||||
5333 | MemorySanitizerVisitor Visitor(F, *this, TLI); | |||
5334 | ||||
5335 | // Clear out readonly/readnone attributes. | |||
5336 | AttrBuilder B; | |||
5337 | B.addAttribute(Attribute::ReadOnly) | |||
5338 | .addAttribute(Attribute::ReadNone) | |||
5339 | .addAttribute(Attribute::WriteOnly) | |||
5340 | .addAttribute(Attribute::ArgMemOnly) | |||
5341 | .addAttribute(Attribute::Speculatable); | |||
5342 | F.removeAttributes(AttributeList::FunctionIndex, B); | |||
5343 | ||||
5344 | return Visitor.runOnFunction(); | |||
5345 | } |