File: | lib/Transforms/Instrumentation/MemorySanitizer.cpp |
Warning: | line 2417, column 23 1st function call argument is an uninitialized value |
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1 | //===- MemorySanitizer.cpp - detector of uninitialized reads --------------===// | |||
2 | // | |||
3 | // The LLVM Compiler Infrastructure | |||
4 | // | |||
5 | // This file is distributed under the University of Illinois Open Source | |||
6 | // License. See LICENSE.TXT for details. | |||
7 | // | |||
8 | //===----------------------------------------------------------------------===// | |||
9 | // | |||
10 | /// \file | |||
11 | /// This file is a part of MemorySanitizer, a detector of uninitialized | |||
12 | /// reads. | |||
13 | /// | |||
14 | /// The algorithm of the tool is similar to Memcheck | |||
15 | /// (http://goo.gl/QKbem). We associate a few shadow bits with every | |||
16 | /// byte of the application memory, poison the shadow of the malloc-ed | |||
17 | /// or alloca-ed memory, load the shadow bits on every memory read, | |||
18 | /// propagate the shadow bits through some of the arithmetic | |||
19 | /// instruction (including MOV), store the shadow bits on every memory | |||
20 | /// write, report a bug on some other instructions (e.g. JMP) if the | |||
21 | /// associated shadow is poisoned. | |||
22 | /// | |||
23 | /// But there are differences too. The first and the major one: | |||
24 | /// compiler instrumentation instead of binary instrumentation. This | |||
25 | /// gives us much better register allocation, possible compiler | |||
26 | /// optimizations and a fast start-up. But this brings the major issue | |||
27 | /// as well: msan needs to see all program events, including system | |||
28 | /// calls and reads/writes in system libraries, so we either need to | |||
29 | /// compile *everything* with msan or use a binary translation | |||
30 | /// component (e.g. DynamoRIO) to instrument pre-built libraries. | |||
31 | /// Another difference from Memcheck is that we use 8 shadow bits per | |||
32 | /// byte of application memory and use a direct shadow mapping. This | |||
33 | /// greatly simplifies the instrumentation code and avoids races on | |||
34 | /// shadow updates (Memcheck is single-threaded so races are not a | |||
35 | /// concern there. Memcheck uses 2 shadow bits per byte with a slow | |||
36 | /// path storage that uses 8 bits per byte). | |||
37 | /// | |||
38 | /// The default value of shadow is 0, which means "clean" (not poisoned). | |||
39 | /// | |||
40 | /// Every module initializer should call __msan_init to ensure that the | |||
41 | /// shadow memory is ready. On error, __msan_warning is called. Since | |||
42 | /// parameters and return values may be passed via registers, we have a | |||
43 | /// specialized thread-local shadow for return values | |||
44 | /// (__msan_retval_tls) and parameters (__msan_param_tls). | |||
45 | /// | |||
46 | /// Origin tracking. | |||
47 | /// | |||
48 | /// MemorySanitizer can track origins (allocation points) of all uninitialized | |||
49 | /// values. This behavior is controlled with a flag (msan-track-origins) and is | |||
50 | /// disabled by default. | |||
51 | /// | |||
52 | /// Origins are 4-byte values created and interpreted by the runtime library. | |||
53 | /// They are stored in a second shadow mapping, one 4-byte value for 4 bytes | |||
54 | /// of application memory. Propagation of origins is basically a bunch of | |||
55 | /// "select" instructions that pick the origin of a dirty argument, if an | |||
56 | /// instruction has one. | |||
57 | /// | |||
58 | /// Every 4 aligned, consecutive bytes of application memory have one origin | |||
59 | /// value associated with them. If these bytes contain uninitialized data | |||
60 | /// coming from 2 different allocations, the last store wins. Because of this, | |||
61 | /// MemorySanitizer reports can show unrelated origins, but this is unlikely in | |||
62 | /// practice. | |||
63 | /// | |||
64 | /// Origins are meaningless for fully initialized values, so MemorySanitizer | |||
65 | /// avoids storing origin to memory when a fully initialized value is stored. | |||
66 | /// This way it avoids needless overwritting origin of the 4-byte region on | |||
67 | /// a short (i.e. 1 byte) clean store, and it is also good for performance. | |||
68 | /// | |||
69 | /// Atomic handling. | |||
70 | /// | |||
71 | /// Ideally, every atomic store of application value should update the | |||
72 | /// corresponding shadow location in an atomic way. Unfortunately, atomic store | |||
73 | /// of two disjoint locations can not be done without severe slowdown. | |||
74 | /// | |||
75 | /// Therefore, we implement an approximation that may err on the safe side. | |||
76 | /// In this implementation, every atomically accessed location in the program | |||
77 | /// may only change from (partially) uninitialized to fully initialized, but | |||
78 | /// not the other way around. We load the shadow _after_ the application load, | |||
79 | /// and we store the shadow _before_ the app store. Also, we always store clean | |||
80 | /// shadow (if the application store is atomic). This way, if the store-load | |||
81 | /// pair constitutes a happens-before arc, shadow store and load are correctly | |||
82 | /// ordered such that the load will get either the value that was stored, or | |||
83 | /// some later value (which is always clean). | |||
84 | /// | |||
85 | /// This does not work very well with Compare-And-Swap (CAS) and | |||
86 | /// Read-Modify-Write (RMW) operations. To follow the above logic, CAS and RMW | |||
87 | /// must store the new shadow before the app operation, and load the shadow | |||
88 | /// after the app operation. Computers don't work this way. Current | |||
89 | /// implementation ignores the load aspect of CAS/RMW, always returning a clean | |||
90 | /// value. It implements the store part as a simple atomic store by storing a | |||
91 | /// clean shadow. | |||
92 | /// | |||
93 | /// Instrumenting inline assembly. | |||
94 | /// | |||
95 | /// For inline assembly code LLVM has little idea about which memory locations | |||
96 | /// become initialized depending on the arguments. It can be possible to figure | |||
97 | /// out which arguments are meant to point to inputs and outputs, but the | |||
98 | /// actual semantics can be only visible at runtime. In the Linux kernel it's | |||
99 | /// also possible that the arguments only indicate the offset for a base taken | |||
100 | /// from a segment register, so it's dangerous to treat any asm() arguments as | |||
101 | /// pointers. We take a conservative approach generating calls to | |||
102 | /// __msan_instrument_asm_store(ptr, size) | |||
103 | /// , which defer the memory unpoisoning to the runtime library. | |||
104 | /// The latter can perform more complex address checks to figure out whether | |||
105 | /// it's safe to touch the shadow memory. | |||
106 | /// Like with atomic operations, we call __msan_instrument_asm_store() before | |||
107 | /// the assembly call, so that changes to the shadow memory will be seen by | |||
108 | /// other threads together with main memory initialization. | |||
109 | /// | |||
110 | /// KernelMemorySanitizer (KMSAN) implementation. | |||
111 | /// | |||
112 | /// The major differences between KMSAN and MSan instrumentation are: | |||
113 | /// - KMSAN always tracks the origins and implies msan-keep-going=true; | |||
114 | /// - KMSAN allocates shadow and origin memory for each page separately, so | |||
115 | /// there are no explicit accesses to shadow and origin in the | |||
116 | /// instrumentation. | |||
117 | /// Shadow and origin values for a particular X-byte memory location | |||
118 | /// (X=1,2,4,8) are accessed through pointers obtained via the | |||
119 | /// __msan_metadata_ptr_for_load_X(ptr) | |||
120 | /// __msan_metadata_ptr_for_store_X(ptr) | |||
121 | /// functions. The corresponding functions check that the X-byte accesses | |||
122 | /// are possible and returns the pointers to shadow and origin memory. | |||
123 | /// Arbitrary sized accesses are handled with: | |||
124 | /// __msan_metadata_ptr_for_load_n(ptr, size) | |||
125 | /// __msan_metadata_ptr_for_store_n(ptr, size); | |||
126 | /// - TLS variables are stored in a single per-task struct. A call to a | |||
127 | /// function __msan_get_context_state() returning a pointer to that struct | |||
128 | /// is inserted into every instrumented function before the entry block; | |||
129 | /// - __msan_warning() takes a 32-bit origin parameter; | |||
130 | /// - local variables are poisoned with __msan_poison_alloca() upon function | |||
131 | /// entry and unpoisoned with __msan_unpoison_alloca() before leaving the | |||
132 | /// function; | |||
133 | /// - the pass doesn't declare any global variables or add global constructors | |||
134 | /// to the translation unit. | |||
135 | /// | |||
136 | /// Also, KMSAN currently ignores uninitialized memory passed into inline asm | |||
137 | /// calls, making sure we're on the safe side wrt. possible false positives. | |||
138 | /// | |||
139 | /// KernelMemorySanitizer only supports X86_64 at the moment. | |||
140 | /// | |||
141 | //===----------------------------------------------------------------------===// | |||
142 | ||||
143 | #include "llvm/ADT/APInt.h" | |||
144 | #include "llvm/ADT/ArrayRef.h" | |||
145 | #include "llvm/ADT/DepthFirstIterator.h" | |||
146 | #include "llvm/ADT/SmallString.h" | |||
147 | #include "llvm/ADT/SmallVector.h" | |||
148 | #include "llvm/ADT/StringExtras.h" | |||
149 | #include "llvm/ADT/StringRef.h" | |||
150 | #include "llvm/ADT/Triple.h" | |||
151 | #include "llvm/Analysis/TargetLibraryInfo.h" | |||
152 | #include "llvm/Transforms/Utils/Local.h" | |||
153 | #include "llvm/IR/Argument.h" | |||
154 | #include "llvm/IR/Attributes.h" | |||
155 | #include "llvm/IR/BasicBlock.h" | |||
156 | #include "llvm/IR/CallSite.h" | |||
157 | #include "llvm/IR/CallingConv.h" | |||
158 | #include "llvm/IR/Constant.h" | |||
159 | #include "llvm/IR/Constants.h" | |||
160 | #include "llvm/IR/DataLayout.h" | |||
161 | #include "llvm/IR/DerivedTypes.h" | |||
162 | #include "llvm/IR/Function.h" | |||
163 | #include "llvm/IR/GlobalValue.h" | |||
164 | #include "llvm/IR/GlobalVariable.h" | |||
165 | #include "llvm/IR/IRBuilder.h" | |||
166 | #include "llvm/IR/InlineAsm.h" | |||
167 | #include "llvm/IR/InstVisitor.h" | |||
168 | #include "llvm/IR/InstrTypes.h" | |||
169 | #include "llvm/IR/Instruction.h" | |||
170 | #include "llvm/IR/Instructions.h" | |||
171 | #include "llvm/IR/IntrinsicInst.h" | |||
172 | #include "llvm/IR/Intrinsics.h" | |||
173 | #include "llvm/IR/LLVMContext.h" | |||
174 | #include "llvm/IR/MDBuilder.h" | |||
175 | #include "llvm/IR/Module.h" | |||
176 | #include "llvm/IR/Type.h" | |||
177 | #include "llvm/IR/Value.h" | |||
178 | #include "llvm/IR/ValueMap.h" | |||
179 | #include "llvm/Pass.h" | |||
180 | #include "llvm/Support/AtomicOrdering.h" | |||
181 | #include "llvm/Support/Casting.h" | |||
182 | #include "llvm/Support/CommandLine.h" | |||
183 | #include "llvm/Support/Compiler.h" | |||
184 | #include "llvm/Support/Debug.h" | |||
185 | #include "llvm/Support/ErrorHandling.h" | |||
186 | #include "llvm/Support/MathExtras.h" | |||
187 | #include "llvm/Support/raw_ostream.h" | |||
188 | #include "llvm/Transforms/Instrumentation.h" | |||
189 | #include "llvm/Transforms/Utils/BasicBlockUtils.h" | |||
190 | #include "llvm/Transforms/Utils/ModuleUtils.h" | |||
191 | #include <algorithm> | |||
192 | #include <cassert> | |||
193 | #include <cstddef> | |||
194 | #include <cstdint> | |||
195 | #include <memory> | |||
196 | #include <string> | |||
197 | #include <tuple> | |||
198 | ||||
199 | using namespace llvm; | |||
200 | ||||
201 | #define DEBUG_TYPE"msan" "msan" | |||
202 | ||||
203 | static const unsigned kOriginSize = 4; | |||
204 | static const unsigned kMinOriginAlignment = 4; | |||
205 | static const unsigned kShadowTLSAlignment = 8; | |||
206 | ||||
207 | // These constants must be kept in sync with the ones in msan.h. | |||
208 | static const unsigned kParamTLSSize = 800; | |||
209 | static const unsigned kRetvalTLSSize = 800; | |||
210 | ||||
211 | // Accesses sizes are powers of two: 1, 2, 4, 8. | |||
212 | static const size_t kNumberOfAccessSizes = 4; | |||
213 | ||||
214 | /// Track origins of uninitialized values. | |||
215 | /// | |||
216 | /// Adds a section to MemorySanitizer report that points to the allocation | |||
217 | /// (stack or heap) the uninitialized bits came from originally. | |||
218 | static cl::opt<int> ClTrackOrigins("msan-track-origins", | |||
219 | cl::desc("Track origins (allocation sites) of poisoned memory"), | |||
220 | cl::Hidden, cl::init(0)); | |||
221 | ||||
222 | static cl::opt<bool> ClKeepGoing("msan-keep-going", | |||
223 | cl::desc("keep going after reporting a UMR"), | |||
224 | cl::Hidden, cl::init(false)); | |||
225 | ||||
226 | static cl::opt<bool> ClPoisonStack("msan-poison-stack", | |||
227 | cl::desc("poison uninitialized stack variables"), | |||
228 | cl::Hidden, cl::init(true)); | |||
229 | ||||
230 | static cl::opt<bool> ClPoisonStackWithCall("msan-poison-stack-with-call", | |||
231 | cl::desc("poison uninitialized stack variables with a call"), | |||
232 | cl::Hidden, cl::init(false)); | |||
233 | ||||
234 | static cl::opt<int> ClPoisonStackPattern("msan-poison-stack-pattern", | |||
235 | cl::desc("poison uninitialized stack variables with the given pattern"), | |||
236 | cl::Hidden, cl::init(0xff)); | |||
237 | ||||
238 | static cl::opt<bool> ClPoisonUndef("msan-poison-undef", | |||
239 | cl::desc("poison undef temps"), | |||
240 | cl::Hidden, cl::init(true)); | |||
241 | ||||
242 | static cl::opt<bool> ClHandleICmp("msan-handle-icmp", | |||
243 | cl::desc("propagate shadow through ICmpEQ and ICmpNE"), | |||
244 | cl::Hidden, cl::init(true)); | |||
245 | ||||
246 | static cl::opt<bool> ClHandleICmpExact("msan-handle-icmp-exact", | |||
247 | cl::desc("exact handling of relational integer ICmp"), | |||
248 | cl::Hidden, cl::init(false)); | |||
249 | ||||
250 | // When compiling the Linux kernel, we sometimes see false positives related to | |||
251 | // MSan being unable to understand that inline assembly calls may initialize | |||
252 | // local variables. | |||
253 | // This flag makes the compiler conservatively unpoison every memory location | |||
254 | // passed into an assembly call. Note that this may cause false positives. | |||
255 | // Because it's impossible to figure out the array sizes, we can only unpoison | |||
256 | // the first sizeof(type) bytes for each type* pointer. | |||
257 | // The instrumentation is only enabled in KMSAN builds, and only if | |||
258 | // -msan-handle-asm-conservative is on. This is done because we may want to | |||
259 | // quickly disable assembly instrumentation when it breaks. | |||
260 | static cl::opt<bool> ClHandleAsmConservative( | |||
261 | "msan-handle-asm-conservative", | |||
262 | cl::desc("conservative handling of inline assembly"), cl::Hidden, | |||
263 | cl::init(true)); | |||
264 | ||||
265 | // This flag controls whether we check the shadow of the address | |||
266 | // operand of load or store. Such bugs are very rare, since load from | |||
267 | // a garbage address typically results in SEGV, but still happen | |||
268 | // (e.g. only lower bits of address are garbage, or the access happens | |||
269 | // early at program startup where malloc-ed memory is more likely to | |||
270 | // be zeroed. As of 2012-08-28 this flag adds 20% slowdown. | |||
271 | static cl::opt<bool> ClCheckAccessAddress("msan-check-access-address", | |||
272 | cl::desc("report accesses through a pointer which has poisoned shadow"), | |||
273 | cl::Hidden, cl::init(true)); | |||
274 | ||||
275 | static cl::opt<bool> ClDumpStrictInstructions("msan-dump-strict-instructions", | |||
276 | cl::desc("print out instructions with default strict semantics"), | |||
277 | cl::Hidden, cl::init(false)); | |||
278 | ||||
279 | static cl::opt<int> ClInstrumentationWithCallThreshold( | |||
280 | "msan-instrumentation-with-call-threshold", | |||
281 | cl::desc( | |||
282 | "If the function being instrumented requires more than " | |||
283 | "this number of checks and origin stores, use callbacks instead of " | |||
284 | "inline checks (-1 means never use callbacks)."), | |||
285 | cl::Hidden, cl::init(3500)); | |||
286 | ||||
287 | static cl::opt<bool> | |||
288 | ClEnableKmsan("msan-kernel", | |||
289 | cl::desc("Enable KernelMemorySanitizer instrumentation"), | |||
290 | cl::Hidden, cl::init(false)); | |||
291 | ||||
292 | // This is an experiment to enable handling of cases where shadow is a non-zero | |||
293 | // compile-time constant. For some unexplainable reason they were silently | |||
294 | // ignored in the instrumentation. | |||
295 | static cl::opt<bool> ClCheckConstantShadow("msan-check-constant-shadow", | |||
296 | cl::desc("Insert checks for constant shadow values"), | |||
297 | cl::Hidden, cl::init(false)); | |||
298 | ||||
299 | // This is off by default because of a bug in gold: | |||
300 | // https://sourceware.org/bugzilla/show_bug.cgi?id=19002 | |||
301 | static cl::opt<bool> ClWithComdat("msan-with-comdat", | |||
302 | cl::desc("Place MSan constructors in comdat sections"), | |||
303 | cl::Hidden, cl::init(false)); | |||
304 | ||||
305 | // These options allow to specify custom memory map parameters | |||
306 | // See MemoryMapParams for details. | |||
307 | static cl::opt<unsigned long long> ClAndMask("msan-and-mask", | |||
308 | cl::desc("Define custom MSan AndMask"), | |||
309 | cl::Hidden, cl::init(0)); | |||
310 | ||||
311 | static cl::opt<unsigned long long> ClXorMask("msan-xor-mask", | |||
312 | cl::desc("Define custom MSan XorMask"), | |||
313 | cl::Hidden, cl::init(0)); | |||
314 | ||||
315 | static cl::opt<unsigned long long> ClShadowBase("msan-shadow-base", | |||
316 | cl::desc("Define custom MSan ShadowBase"), | |||
317 | cl::Hidden, cl::init(0)); | |||
318 | ||||
319 | static cl::opt<unsigned long long> ClOriginBase("msan-origin-base", | |||
320 | cl::desc("Define custom MSan OriginBase"), | |||
321 | cl::Hidden, cl::init(0)); | |||
322 | ||||
323 | static const char *const kMsanModuleCtorName = "msan.module_ctor"; | |||
324 | static const char *const kMsanInitName = "__msan_init"; | |||
325 | ||||
326 | namespace { | |||
327 | ||||
328 | // Memory map parameters used in application-to-shadow address calculation. | |||
329 | // Offset = (Addr & ~AndMask) ^ XorMask | |||
330 | // Shadow = ShadowBase + Offset | |||
331 | // Origin = OriginBase + Offset | |||
332 | struct MemoryMapParams { | |||
333 | uint64_t AndMask; | |||
334 | uint64_t XorMask; | |||
335 | uint64_t ShadowBase; | |||
336 | uint64_t OriginBase; | |||
337 | }; | |||
338 | ||||
339 | struct PlatformMemoryMapParams { | |||
340 | const MemoryMapParams *bits32; | |||
341 | const MemoryMapParams *bits64; | |||
342 | }; | |||
343 | ||||
344 | } // end anonymous namespace | |||
345 | ||||
346 | // i386 Linux | |||
347 | static const MemoryMapParams Linux_I386_MemoryMapParams = { | |||
348 | 0x000080000000, // AndMask | |||
349 | 0, // XorMask (not used) | |||
350 | 0, // ShadowBase (not used) | |||
351 | 0x000040000000, // OriginBase | |||
352 | }; | |||
353 | ||||
354 | // x86_64 Linux | |||
355 | static const MemoryMapParams Linux_X86_64_MemoryMapParams = { | |||
356 | #ifdef MSAN_LINUX_X86_64_OLD_MAPPING | |||
357 | 0x400000000000, // AndMask | |||
358 | 0, // XorMask (not used) | |||
359 | 0, // ShadowBase (not used) | |||
360 | 0x200000000000, // OriginBase | |||
361 | #else | |||
362 | 0, // AndMask (not used) | |||
363 | 0x500000000000, // XorMask | |||
364 | 0, // ShadowBase (not used) | |||
365 | 0x100000000000, // OriginBase | |||
366 | #endif | |||
367 | }; | |||
368 | ||||
369 | // mips64 Linux | |||
370 | static const MemoryMapParams Linux_MIPS64_MemoryMapParams = { | |||
371 | 0, // AndMask (not used) | |||
372 | 0x008000000000, // XorMask | |||
373 | 0, // ShadowBase (not used) | |||
374 | 0x002000000000, // OriginBase | |||
375 | }; | |||
376 | ||||
377 | // ppc64 Linux | |||
378 | static const MemoryMapParams Linux_PowerPC64_MemoryMapParams = { | |||
379 | 0xE00000000000, // AndMask | |||
380 | 0x100000000000, // XorMask | |||
381 | 0x080000000000, // ShadowBase | |||
382 | 0x1C0000000000, // OriginBase | |||
383 | }; | |||
384 | ||||
385 | // aarch64 Linux | |||
386 | static const MemoryMapParams Linux_AArch64_MemoryMapParams = { | |||
387 | 0, // AndMask (not used) | |||
388 | 0x06000000000, // XorMask | |||
389 | 0, // ShadowBase (not used) | |||
390 | 0x01000000000, // OriginBase | |||
391 | }; | |||
392 | ||||
393 | // i386 FreeBSD | |||
394 | static const MemoryMapParams FreeBSD_I386_MemoryMapParams = { | |||
395 | 0x000180000000, // AndMask | |||
396 | 0x000040000000, // XorMask | |||
397 | 0x000020000000, // ShadowBase | |||
398 | 0x000700000000, // OriginBase | |||
399 | }; | |||
400 | ||||
401 | // x86_64 FreeBSD | |||
402 | static const MemoryMapParams FreeBSD_X86_64_MemoryMapParams = { | |||
403 | 0xc00000000000, // AndMask | |||
404 | 0x200000000000, // XorMask | |||
405 | 0x100000000000, // ShadowBase | |||
406 | 0x380000000000, // OriginBase | |||
407 | }; | |||
408 | ||||
409 | // x86_64 NetBSD | |||
410 | static const MemoryMapParams NetBSD_X86_64_MemoryMapParams = { | |||
411 | 0, // AndMask | |||
412 | 0x500000000000, // XorMask | |||
413 | 0, // ShadowBase | |||
414 | 0x100000000000, // OriginBase | |||
415 | }; | |||
416 | ||||
417 | static const PlatformMemoryMapParams Linux_X86_MemoryMapParams = { | |||
418 | &Linux_I386_MemoryMapParams, | |||
419 | &Linux_X86_64_MemoryMapParams, | |||
420 | }; | |||
421 | ||||
422 | static const PlatformMemoryMapParams Linux_MIPS_MemoryMapParams = { | |||
423 | nullptr, | |||
424 | &Linux_MIPS64_MemoryMapParams, | |||
425 | }; | |||
426 | ||||
427 | static const PlatformMemoryMapParams Linux_PowerPC_MemoryMapParams = { | |||
428 | nullptr, | |||
429 | &Linux_PowerPC64_MemoryMapParams, | |||
430 | }; | |||
431 | ||||
432 | static const PlatformMemoryMapParams Linux_ARM_MemoryMapParams = { | |||
433 | nullptr, | |||
434 | &Linux_AArch64_MemoryMapParams, | |||
435 | }; | |||
436 | ||||
437 | static const PlatformMemoryMapParams FreeBSD_X86_MemoryMapParams = { | |||
438 | &FreeBSD_I386_MemoryMapParams, | |||
439 | &FreeBSD_X86_64_MemoryMapParams, | |||
440 | }; | |||
441 | ||||
442 | static const PlatformMemoryMapParams NetBSD_X86_MemoryMapParams = { | |||
443 | nullptr, | |||
444 | &NetBSD_X86_64_MemoryMapParams, | |||
445 | }; | |||
446 | ||||
447 | namespace { | |||
448 | ||||
449 | /// An instrumentation pass implementing detection of uninitialized | |||
450 | /// reads. | |||
451 | /// | |||
452 | /// MemorySanitizer: instrument the code in module to find | |||
453 | /// uninitialized reads. | |||
454 | class MemorySanitizer : public FunctionPass { | |||
455 | public: | |||
456 | // Pass identification, replacement for typeid. | |||
457 | static char ID; | |||
458 | ||||
459 | MemorySanitizer(int TrackOrigins = 0, bool Recover = false, | |||
460 | bool EnableKmsan = false) | |||
461 | : FunctionPass(ID) { | |||
462 | this->CompileKernel = | |||
463 | ClEnableKmsan.getNumOccurrences() > 0 ? ClEnableKmsan : EnableKmsan; | |||
464 | if (ClTrackOrigins.getNumOccurrences() > 0) | |||
465 | this->TrackOrigins = ClTrackOrigins; | |||
466 | else | |||
467 | this->TrackOrigins = this->CompileKernel ? 2 : TrackOrigins; | |||
468 | this->Recover = ClKeepGoing.getNumOccurrences() > 0 | |||
469 | ? ClKeepGoing | |||
470 | : (this->CompileKernel | Recover); | |||
471 | } | |||
472 | StringRef getPassName() const override { return "MemorySanitizer"; } | |||
473 | ||||
474 | void getAnalysisUsage(AnalysisUsage &AU) const override { | |||
475 | AU.addRequired<TargetLibraryInfoWrapperPass>(); | |||
476 | } | |||
477 | ||||
478 | bool runOnFunction(Function &F) override; | |||
479 | bool doInitialization(Module &M) override; | |||
480 | ||||
481 | private: | |||
482 | friend struct MemorySanitizerVisitor; | |||
483 | friend struct VarArgAMD64Helper; | |||
484 | friend struct VarArgMIPS64Helper; | |||
485 | friend struct VarArgAArch64Helper; | |||
486 | friend struct VarArgPowerPC64Helper; | |||
487 | ||||
488 | void initializeCallbacks(Module &M); | |||
489 | void createKernelApi(Module &M); | |||
490 | void createUserspaceApi(Module &M); | |||
491 | ||||
492 | /// True if we're compiling the Linux kernel. | |||
493 | bool CompileKernel; | |||
494 | ||||
495 | /// Track origins (allocation points) of uninitialized values. | |||
496 | int TrackOrigins; | |||
497 | bool Recover; | |||
498 | ||||
499 | LLVMContext *C; | |||
500 | Type *IntptrTy; | |||
501 | Type *OriginTy; | |||
502 | ||||
503 | // XxxTLS variables represent the per-thread state in MSan and per-task state | |||
504 | // in KMSAN. | |||
505 | // For the userspace these point to thread-local globals. In the kernel land | |||
506 | // they point to the members of a per-task struct obtained via a call to | |||
507 | // __msan_get_context_state(). | |||
508 | ||||
509 | /// Thread-local shadow storage for function parameters. | |||
510 | Value *ParamTLS; | |||
511 | ||||
512 | /// Thread-local origin storage for function parameters. | |||
513 | Value *ParamOriginTLS; | |||
514 | ||||
515 | /// Thread-local shadow storage for function return value. | |||
516 | Value *RetvalTLS; | |||
517 | ||||
518 | /// Thread-local origin storage for function return value. | |||
519 | Value *RetvalOriginTLS; | |||
520 | ||||
521 | /// Thread-local shadow storage for in-register va_arg function | |||
522 | /// parameters (x86_64-specific). | |||
523 | Value *VAArgTLS; | |||
524 | ||||
525 | /// Thread-local shadow storage for in-register va_arg function | |||
526 | /// parameters (x86_64-specific). | |||
527 | Value *VAArgOriginTLS; | |||
528 | ||||
529 | /// Thread-local shadow storage for va_arg overflow area | |||
530 | /// (x86_64-specific). | |||
531 | Value *VAArgOverflowSizeTLS; | |||
532 | ||||
533 | /// Thread-local space used to pass origin value to the UMR reporting | |||
534 | /// function. | |||
535 | Value *OriginTLS; | |||
536 | ||||
537 | /// Are the instrumentation callbacks set up? | |||
538 | bool CallbacksInitialized = false; | |||
539 | ||||
540 | /// The run-time callback to print a warning. | |||
541 | Value *WarningFn; | |||
542 | ||||
543 | // These arrays are indexed by log2(AccessSize). | |||
544 | Value *MaybeWarningFn[kNumberOfAccessSizes]; | |||
545 | Value *MaybeStoreOriginFn[kNumberOfAccessSizes]; | |||
546 | ||||
547 | /// Run-time helper that generates a new origin value for a stack | |||
548 | /// allocation. | |||
549 | Value *MsanSetAllocaOrigin4Fn; | |||
550 | ||||
551 | /// Run-time helper that poisons stack on function entry. | |||
552 | Value *MsanPoisonStackFn; | |||
553 | ||||
554 | /// Run-time helper that records a store (or any event) of an | |||
555 | /// uninitialized value and returns an updated origin id encoding this info. | |||
556 | Value *MsanChainOriginFn; | |||
557 | ||||
558 | /// MSan runtime replacements for memmove, memcpy and memset. | |||
559 | Value *MemmoveFn, *MemcpyFn, *MemsetFn; | |||
560 | ||||
561 | /// KMSAN callback for task-local function argument shadow. | |||
562 | Value *MsanGetContextStateFn; | |||
563 | ||||
564 | /// Functions for poisoning/unpoisoning local variables | |||
565 | Value *MsanPoisonAllocaFn, *MsanUnpoisonAllocaFn; | |||
566 | ||||
567 | /// Each of the MsanMetadataPtrXxx functions returns a pair of shadow/origin | |||
568 | /// pointers. | |||
569 | Value *MsanMetadataPtrForLoadN, *MsanMetadataPtrForStoreN; | |||
570 | Value *MsanMetadataPtrForLoad_1_8[4]; | |||
571 | Value *MsanMetadataPtrForStore_1_8[4]; | |||
572 | Value *MsanInstrumentAsmStoreFn; | |||
573 | ||||
574 | /// Helper to choose between different MsanMetadataPtrXxx(). | |||
575 | Value *getKmsanShadowOriginAccessFn(bool isStore, int size); | |||
576 | ||||
577 | /// Memory map parameters used in application-to-shadow calculation. | |||
578 | const MemoryMapParams *MapParams; | |||
579 | ||||
580 | /// Custom memory map parameters used when -msan-shadow-base or | |||
581 | // -msan-origin-base is provided. | |||
582 | MemoryMapParams CustomMapParams; | |||
583 | ||||
584 | MDNode *ColdCallWeights; | |||
585 | ||||
586 | /// Branch weights for origin store. | |||
587 | MDNode *OriginStoreWeights; | |||
588 | ||||
589 | /// An empty volatile inline asm that prevents callback merge. | |||
590 | InlineAsm *EmptyAsm; | |||
591 | ||||
592 | Function *MsanCtorFunction; | |||
593 | }; | |||
594 | ||||
595 | } // end anonymous namespace | |||
596 | ||||
597 | char MemorySanitizer::ID = 0; | |||
598 | ||||
599 | INITIALIZE_PASS_BEGIN(static void *initializeMemorySanitizerPassOnce(PassRegistry & Registry) { | |||
600 | MemorySanitizer, "msan",static void *initializeMemorySanitizerPassOnce(PassRegistry & Registry) { | |||
601 | "MemorySanitizer: detects uninitialized reads.", false, false)static void *initializeMemorySanitizerPassOnce(PassRegistry & Registry) { | |||
602 | INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)initializeTargetLibraryInfoWrapperPassPass(Registry); | |||
603 | INITIALIZE_PASS_END(PassInfo *PI = new PassInfo( "MemorySanitizer: detects uninitialized reads." , "msan", &MemorySanitizer::ID, PassInfo::NormalCtor_t(callDefaultCtor <MemorySanitizer>), false, false); Registry.registerPass (*PI, true); return PI; } static llvm::once_flag InitializeMemorySanitizerPassFlag ; void llvm::initializeMemorySanitizerPass(PassRegistry & Registry) { llvm::call_once(InitializeMemorySanitizerPassFlag , initializeMemorySanitizerPassOnce, std::ref(Registry)); } | |||
604 | MemorySanitizer, "msan",PassInfo *PI = new PassInfo( "MemorySanitizer: detects uninitialized reads." , "msan", &MemorySanitizer::ID, PassInfo::NormalCtor_t(callDefaultCtor <MemorySanitizer>), false, false); Registry.registerPass (*PI, true); return PI; } static llvm::once_flag InitializeMemorySanitizerPassFlag ; void llvm::initializeMemorySanitizerPass(PassRegistry & Registry) { llvm::call_once(InitializeMemorySanitizerPassFlag , initializeMemorySanitizerPassOnce, std::ref(Registry)); } | |||
605 | "MemorySanitizer: detects uninitialized reads.", false, false)PassInfo *PI = new PassInfo( "MemorySanitizer: detects uninitialized reads." , "msan", &MemorySanitizer::ID, PassInfo::NormalCtor_t(callDefaultCtor <MemorySanitizer>), false, false); Registry.registerPass (*PI, true); return PI; } static llvm::once_flag InitializeMemorySanitizerPassFlag ; void llvm::initializeMemorySanitizerPass(PassRegistry & Registry) { llvm::call_once(InitializeMemorySanitizerPassFlag , initializeMemorySanitizerPassOnce, std::ref(Registry)); } | |||
606 | ||||
607 | FunctionPass *llvm::createMemorySanitizerPass(int TrackOrigins, bool Recover, | |||
608 | bool CompileKernel) { | |||
609 | return new MemorySanitizer(TrackOrigins, Recover, CompileKernel); | |||
610 | } | |||
611 | ||||
612 | /// Create a non-const global initialized with the given string. | |||
613 | /// | |||
614 | /// Creates a writable global for Str so that we can pass it to the | |||
615 | /// run-time lib. Runtime uses first 4 bytes of the string to store the | |||
616 | /// frame ID, so the string needs to be mutable. | |||
617 | static GlobalVariable *createPrivateNonConstGlobalForString(Module &M, | |||
618 | StringRef Str) { | |||
619 | Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str); | |||
620 | return new GlobalVariable(M, StrConst->getType(), /*isConstant=*/false, | |||
621 | GlobalValue::PrivateLinkage, StrConst, ""); | |||
622 | } | |||
623 | ||||
624 | /// Create KMSAN API callbacks. | |||
625 | void MemorySanitizer::createKernelApi(Module &M) { | |||
626 | IRBuilder<> IRB(*C); | |||
627 | ||||
628 | // These will be initialized in insertKmsanPrologue(). | |||
629 | RetvalTLS = nullptr; | |||
630 | RetvalOriginTLS = nullptr; | |||
631 | ParamTLS = nullptr; | |||
632 | ParamOriginTLS = nullptr; | |||
633 | VAArgTLS = nullptr; | |||
634 | VAArgOriginTLS = nullptr; | |||
635 | VAArgOverflowSizeTLS = nullptr; | |||
636 | // OriginTLS is unused in the kernel. | |||
637 | OriginTLS = nullptr; | |||
638 | ||||
639 | // __msan_warning() in the kernel takes an origin. | |||
640 | WarningFn = M.getOrInsertFunction("__msan_warning", IRB.getVoidTy(), | |||
641 | IRB.getInt32Ty()); | |||
642 | // Requests the per-task context state (kmsan_context_state*) from the | |||
643 | // runtime library. | |||
644 | MsanGetContextStateFn = M.getOrInsertFunction( | |||
645 | "__msan_get_context_state", | |||
646 | PointerType::get( | |||
647 | StructType::get(ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8), | |||
648 | ArrayType::get(IRB.getInt64Ty(), kRetvalTLSSize / 8), | |||
649 | ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8), | |||
650 | ArrayType::get(IRB.getInt64Ty(), | |||
651 | kParamTLSSize / 8), /* va_arg_origin */ | |||
652 | IRB.getInt64Ty(), | |||
653 | ArrayType::get(OriginTy, kParamTLSSize / 4), OriginTy, | |||
654 | OriginTy), | |||
655 | 0)); | |||
656 | ||||
657 | Type *RetTy = StructType::get(PointerType::get(IRB.getInt8Ty(), 0), | |||
658 | PointerType::get(IRB.getInt32Ty(), 0)); | |||
659 | ||||
660 | for (int ind = 0, size = 1; ind < 4; ind++, size <<= 1) { | |||
661 | std::string name_load = | |||
662 | "__msan_metadata_ptr_for_load_" + std::to_string(size); | |||
663 | std::string name_store = | |||
664 | "__msan_metadata_ptr_for_store_" + std::to_string(size); | |||
665 | MsanMetadataPtrForLoad_1_8[ind] = M.getOrInsertFunction( | |||
666 | name_load, RetTy, PointerType::get(IRB.getInt8Ty(), 0)); | |||
667 | MsanMetadataPtrForStore_1_8[ind] = M.getOrInsertFunction( | |||
668 | name_store, RetTy, PointerType::get(IRB.getInt8Ty(), 0)); | |||
669 | } | |||
670 | ||||
671 | MsanMetadataPtrForLoadN = M.getOrInsertFunction( | |||
672 | "__msan_metadata_ptr_for_load_n", RetTy, | |||
673 | PointerType::get(IRB.getInt8Ty(), 0), IRB.getInt64Ty()); | |||
674 | MsanMetadataPtrForStoreN = M.getOrInsertFunction( | |||
675 | "__msan_metadata_ptr_for_store_n", RetTy, | |||
676 | PointerType::get(IRB.getInt8Ty(), 0), IRB.getInt64Ty()); | |||
677 | ||||
678 | // Functions for poisoning and unpoisoning memory. | |||
679 | MsanPoisonAllocaFn = | |||
680 | M.getOrInsertFunction("__msan_poison_alloca", IRB.getVoidTy(), | |||
681 | IRB.getInt8PtrTy(), IntptrTy, IRB.getInt8PtrTy()); | |||
682 | MsanUnpoisonAllocaFn = M.getOrInsertFunction( | |||
683 | "__msan_unpoison_alloca", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy); | |||
684 | } | |||
685 | ||||
686 | /// Insert declarations for userspace-specific functions and globals. | |||
687 | void MemorySanitizer::createUserspaceApi(Module &M) { | |||
688 | IRBuilder<> IRB(*C); | |||
689 | // Create the callback. | |||
690 | // FIXME: this function should have "Cold" calling conv, | |||
691 | // which is not yet implemented. | |||
692 | StringRef WarningFnName = Recover ? "__msan_warning" | |||
693 | : "__msan_warning_noreturn"; | |||
694 | WarningFn = M.getOrInsertFunction(WarningFnName, IRB.getVoidTy()); | |||
695 | ||||
696 | // Create the global TLS variables. | |||
697 | RetvalTLS = new GlobalVariable( | |||
698 | M, ArrayType::get(IRB.getInt64Ty(), kRetvalTLSSize / 8), false, | |||
699 | GlobalVariable::ExternalLinkage, nullptr, "__msan_retval_tls", nullptr, | |||
700 | GlobalVariable::InitialExecTLSModel); | |||
701 | ||||
702 | RetvalOriginTLS = new GlobalVariable( | |||
703 | M, OriginTy, false, GlobalVariable::ExternalLinkage, nullptr, | |||
704 | "__msan_retval_origin_tls", nullptr, GlobalVariable::InitialExecTLSModel); | |||
705 | ||||
706 | ParamTLS = new GlobalVariable( | |||
707 | M, ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8), false, | |||
708 | GlobalVariable::ExternalLinkage, nullptr, "__msan_param_tls", nullptr, | |||
709 | GlobalVariable::InitialExecTLSModel); | |||
710 | ||||
711 | ParamOriginTLS = new GlobalVariable( | |||
712 | M, ArrayType::get(OriginTy, kParamTLSSize / 4), false, | |||
713 | GlobalVariable::ExternalLinkage, nullptr, "__msan_param_origin_tls", | |||
714 | nullptr, GlobalVariable::InitialExecTLSModel); | |||
715 | ||||
716 | VAArgTLS = new GlobalVariable( | |||
717 | M, ArrayType::get(IRB.getInt64Ty(), kParamTLSSize / 8), false, | |||
718 | GlobalVariable::ExternalLinkage, nullptr, "__msan_va_arg_tls", nullptr, | |||
719 | GlobalVariable::InitialExecTLSModel); | |||
720 | ||||
721 | VAArgOriginTLS = new GlobalVariable( | |||
722 | M, ArrayType::get(OriginTy, kParamTLSSize / 4), false, | |||
723 | GlobalVariable::ExternalLinkage, nullptr, "__msan_va_arg_origin_tls", | |||
724 | nullptr, GlobalVariable::InitialExecTLSModel); | |||
725 | ||||
726 | VAArgOverflowSizeTLS = new GlobalVariable( | |||
727 | M, IRB.getInt64Ty(), false, GlobalVariable::ExternalLinkage, nullptr, | |||
728 | "__msan_va_arg_overflow_size_tls", nullptr, | |||
729 | GlobalVariable::InitialExecTLSModel); | |||
730 | OriginTLS = new GlobalVariable( | |||
731 | M, IRB.getInt32Ty(), false, GlobalVariable::ExternalLinkage, nullptr, | |||
732 | "__msan_origin_tls", nullptr, GlobalVariable::InitialExecTLSModel); | |||
733 | ||||
734 | for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes; | |||
735 | AccessSizeIndex++) { | |||
736 | unsigned AccessSize = 1 << AccessSizeIndex; | |||
737 | std::string FunctionName = "__msan_maybe_warning_" + itostr(AccessSize); | |||
738 | MaybeWarningFn[AccessSizeIndex] = M.getOrInsertFunction( | |||
739 | FunctionName, IRB.getVoidTy(), IRB.getIntNTy(AccessSize * 8), | |||
740 | IRB.getInt32Ty()); | |||
741 | ||||
742 | FunctionName = "__msan_maybe_store_origin_" + itostr(AccessSize); | |||
743 | MaybeStoreOriginFn[AccessSizeIndex] = M.getOrInsertFunction( | |||
744 | FunctionName, IRB.getVoidTy(), IRB.getIntNTy(AccessSize * 8), | |||
745 | IRB.getInt8PtrTy(), IRB.getInt32Ty()); | |||
746 | } | |||
747 | ||||
748 | MsanSetAllocaOrigin4Fn = M.getOrInsertFunction( | |||
749 | "__msan_set_alloca_origin4", IRB.getVoidTy(), IRB.getInt8PtrTy(), IntptrTy, | |||
750 | IRB.getInt8PtrTy(), IntptrTy); | |||
751 | MsanPoisonStackFn = | |||
752 | M.getOrInsertFunction("__msan_poison_stack", IRB.getVoidTy(), | |||
753 | IRB.getInt8PtrTy(), IntptrTy); | |||
754 | } | |||
755 | ||||
756 | /// Insert extern declaration of runtime-provided functions and globals. | |||
757 | void MemorySanitizer::initializeCallbacks(Module &M) { | |||
758 | // Only do this once. | |||
759 | if (CallbacksInitialized) | |||
760 | return; | |||
761 | ||||
762 | IRBuilder<> IRB(*C); | |||
763 | // Initialize callbacks that are common for kernel and userspace | |||
764 | // instrumentation. | |||
765 | MsanChainOriginFn = M.getOrInsertFunction( | |||
766 | "__msan_chain_origin", IRB.getInt32Ty(), IRB.getInt32Ty()); | |||
767 | MemmoveFn = M.getOrInsertFunction( | |||
768 | "__msan_memmove", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), | |||
769 | IRB.getInt8PtrTy(), IntptrTy); | |||
770 | MemcpyFn = M.getOrInsertFunction( | |||
771 | "__msan_memcpy", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), | |||
772 | IntptrTy); | |||
773 | MemsetFn = M.getOrInsertFunction( | |||
774 | "__msan_memset", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IRB.getInt32Ty(), | |||
775 | IntptrTy); | |||
776 | // We insert an empty inline asm after __msan_report* to avoid callback merge. | |||
777 | EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false), | |||
778 | StringRef(""), StringRef(""), | |||
779 | /*hasSideEffects=*/true); | |||
780 | ||||
781 | MsanInstrumentAsmStoreFn = | |||
782 | M.getOrInsertFunction("__msan_instrument_asm_store", IRB.getVoidTy(), | |||
783 | PointerType::get(IRB.getInt8Ty(), 0), IntptrTy); | |||
784 | ||||
785 | if (CompileKernel) { | |||
786 | createKernelApi(M); | |||
787 | } else { | |||
788 | createUserspaceApi(M); | |||
789 | } | |||
790 | CallbacksInitialized = true; | |||
791 | } | |||
792 | ||||
793 | Value *MemorySanitizer::getKmsanShadowOriginAccessFn(bool isStore, int size) { | |||
794 | Value **Fns = | |||
795 | isStore ? MsanMetadataPtrForStore_1_8 : MsanMetadataPtrForLoad_1_8; | |||
796 | switch (size) { | |||
797 | case 1: | |||
798 | return Fns[0]; | |||
799 | case 2: | |||
800 | return Fns[1]; | |||
801 | case 4: | |||
802 | return Fns[2]; | |||
803 | case 8: | |||
804 | return Fns[3]; | |||
805 | default: | |||
806 | return nullptr; | |||
807 | } | |||
808 | } | |||
809 | ||||
810 | /// Module-level initialization. | |||
811 | /// | |||
812 | /// inserts a call to __msan_init to the module's constructor list. | |||
813 | bool MemorySanitizer::doInitialization(Module &M) { | |||
814 | auto &DL = M.getDataLayout(); | |||
815 | ||||
816 | bool ShadowPassed = ClShadowBase.getNumOccurrences() > 0; | |||
817 | bool OriginPassed = ClOriginBase.getNumOccurrences() > 0; | |||
818 | // Check the overrides first | |||
819 | if (ShadowPassed || OriginPassed) { | |||
820 | CustomMapParams.AndMask = ClAndMask; | |||
821 | CustomMapParams.XorMask = ClXorMask; | |||
822 | CustomMapParams.ShadowBase = ClShadowBase; | |||
823 | CustomMapParams.OriginBase = ClOriginBase; | |||
824 | MapParams = &CustomMapParams; | |||
825 | } else { | |||
826 | Triple TargetTriple(M.getTargetTriple()); | |||
827 | switch (TargetTriple.getOS()) { | |||
828 | case Triple::FreeBSD: | |||
829 | switch (TargetTriple.getArch()) { | |||
830 | case Triple::x86_64: | |||
831 | MapParams = FreeBSD_X86_MemoryMapParams.bits64; | |||
832 | break; | |||
833 | case Triple::x86: | |||
834 | MapParams = FreeBSD_X86_MemoryMapParams.bits32; | |||
835 | break; | |||
836 | default: | |||
837 | report_fatal_error("unsupported architecture"); | |||
838 | } | |||
839 | break; | |||
840 | case Triple::NetBSD: | |||
841 | switch (TargetTriple.getArch()) { | |||
842 | case Triple::x86_64: | |||
843 | MapParams = NetBSD_X86_MemoryMapParams.bits64; | |||
844 | break; | |||
845 | default: | |||
846 | report_fatal_error("unsupported architecture"); | |||
847 | } | |||
848 | break; | |||
849 | case Triple::Linux: | |||
850 | switch (TargetTriple.getArch()) { | |||
851 | case Triple::x86_64: | |||
852 | MapParams = Linux_X86_MemoryMapParams.bits64; | |||
853 | break; | |||
854 | case Triple::x86: | |||
855 | MapParams = Linux_X86_MemoryMapParams.bits32; | |||
856 | break; | |||
857 | case Triple::mips64: | |||
858 | case Triple::mips64el: | |||
859 | MapParams = Linux_MIPS_MemoryMapParams.bits64; | |||
860 | break; | |||
861 | case Triple::ppc64: | |||
862 | case Triple::ppc64le: | |||
863 | MapParams = Linux_PowerPC_MemoryMapParams.bits64; | |||
864 | break; | |||
865 | case Triple::aarch64: | |||
866 | case Triple::aarch64_be: | |||
867 | MapParams = Linux_ARM_MemoryMapParams.bits64; | |||
868 | break; | |||
869 | default: | |||
870 | report_fatal_error("unsupported architecture"); | |||
871 | } | |||
872 | break; | |||
873 | default: | |||
874 | report_fatal_error("unsupported operating system"); | |||
875 | } | |||
876 | } | |||
877 | ||||
878 | C = &(M.getContext()); | |||
879 | IRBuilder<> IRB(*C); | |||
880 | IntptrTy = IRB.getIntPtrTy(DL); | |||
881 | OriginTy = IRB.getInt32Ty(); | |||
882 | ||||
883 | ColdCallWeights = MDBuilder(*C).createBranchWeights(1, 1000); | |||
884 | OriginStoreWeights = MDBuilder(*C).createBranchWeights(1, 1000); | |||
885 | ||||
886 | if (!CompileKernel) { | |||
887 | std::tie(MsanCtorFunction, std::ignore) = | |||
888 | createSanitizerCtorAndInitFunctions(M, kMsanModuleCtorName, | |||
889 | kMsanInitName, | |||
890 | /*InitArgTypes=*/{}, | |||
891 | /*InitArgs=*/{}); | |||
892 | if (ClWithComdat) { | |||
893 | Comdat *MsanCtorComdat = M.getOrInsertComdat(kMsanModuleCtorName); | |||
894 | MsanCtorFunction->setComdat(MsanCtorComdat); | |||
895 | appendToGlobalCtors(M, MsanCtorFunction, 0, MsanCtorFunction); | |||
896 | } else { | |||
897 | appendToGlobalCtors(M, MsanCtorFunction, 0); | |||
898 | } | |||
899 | ||||
900 | if (TrackOrigins) | |||
901 | new GlobalVariable(M, IRB.getInt32Ty(), true, GlobalValue::WeakODRLinkage, | |||
902 | IRB.getInt32(TrackOrigins), "__msan_track_origins"); | |||
903 | ||||
904 | if (Recover) | |||
905 | new GlobalVariable(M, IRB.getInt32Ty(), true, GlobalValue::WeakODRLinkage, | |||
906 | IRB.getInt32(Recover), "__msan_keep_going"); | |||
907 | } | |||
908 | return true; | |||
909 | } | |||
910 | ||||
911 | namespace { | |||
912 | ||||
913 | /// A helper class that handles instrumentation of VarArg | |||
914 | /// functions on a particular platform. | |||
915 | /// | |||
916 | /// Implementations are expected to insert the instrumentation | |||
917 | /// necessary to propagate argument shadow through VarArg function | |||
918 | /// calls. Visit* methods are called during an InstVisitor pass over | |||
919 | /// the function, and should avoid creating new basic blocks. A new | |||
920 | /// instance of this class is created for each instrumented function. | |||
921 | struct VarArgHelper { | |||
922 | virtual ~VarArgHelper() = default; | |||
923 | ||||
924 | /// Visit a CallSite. | |||
925 | virtual void visitCallSite(CallSite &CS, IRBuilder<> &IRB) = 0; | |||
926 | ||||
927 | /// Visit a va_start call. | |||
928 | virtual void visitVAStartInst(VAStartInst &I) = 0; | |||
929 | ||||
930 | /// Visit a va_copy call. | |||
931 | virtual void visitVACopyInst(VACopyInst &I) = 0; | |||
932 | ||||
933 | /// Finalize function instrumentation. | |||
934 | /// | |||
935 | /// This method is called after visiting all interesting (see above) | |||
936 | /// instructions in a function. | |||
937 | virtual void finalizeInstrumentation() = 0; | |||
938 | }; | |||
939 | ||||
940 | struct MemorySanitizerVisitor; | |||
941 | ||||
942 | } // end anonymous namespace | |||
943 | ||||
944 | static VarArgHelper *CreateVarArgHelper(Function &Func, MemorySanitizer &Msan, | |||
945 | MemorySanitizerVisitor &Visitor); | |||
946 | ||||
947 | static unsigned TypeSizeToSizeIndex(unsigned TypeSize) { | |||
948 | if (TypeSize <= 8) return 0; | |||
949 | return Log2_32_Ceil((TypeSize + 7) / 8); | |||
950 | } | |||
951 | ||||
952 | namespace { | |||
953 | ||||
954 | /// This class does all the work for a given function. Store and Load | |||
955 | /// instructions store and load corresponding shadow and origin | |||
956 | /// values. Most instructions propagate shadow from arguments to their | |||
957 | /// return values. Certain instructions (most importantly, BranchInst) | |||
958 | /// test their argument shadow and print reports (with a runtime call) if it's | |||
959 | /// non-zero. | |||
960 | struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> { | |||
961 | Function &F; | |||
962 | MemorySanitizer &MS; | |||
963 | SmallVector<PHINode *, 16> ShadowPHINodes, OriginPHINodes; | |||
964 | ValueMap<Value*, Value*> ShadowMap, OriginMap; | |||
965 | std::unique_ptr<VarArgHelper> VAHelper; | |||
966 | const TargetLibraryInfo *TLI; | |||
967 | BasicBlock *ActualFnStart; | |||
968 | ||||
969 | // The following flags disable parts of MSan instrumentation based on | |||
970 | // blacklist contents and command-line options. | |||
971 | bool InsertChecks; | |||
972 | bool PropagateShadow; | |||
973 | bool PoisonStack; | |||
974 | bool PoisonUndef; | |||
975 | bool CheckReturnValue; | |||
976 | ||||
977 | struct ShadowOriginAndInsertPoint { | |||
978 | Value *Shadow; | |||
979 | Value *Origin; | |||
980 | Instruction *OrigIns; | |||
981 | ||||
982 | ShadowOriginAndInsertPoint(Value *S, Value *O, Instruction *I) | |||
983 | : Shadow(S), Origin(O), OrigIns(I) {} | |||
984 | }; | |||
985 | SmallVector<ShadowOriginAndInsertPoint, 16> InstrumentationList; | |||
986 | SmallVector<StoreInst *, 16> StoreList; | |||
987 | ||||
988 | MemorySanitizerVisitor(Function &F, MemorySanitizer &MS) | |||
989 | : F(F), MS(MS), VAHelper(CreateVarArgHelper(F, MS, *this)) { | |||
990 | bool SanitizeFunction = F.hasFnAttribute(Attribute::SanitizeMemory); | |||
991 | InsertChecks = SanitizeFunction; | |||
992 | PropagateShadow = SanitizeFunction; | |||
993 | PoisonStack = SanitizeFunction && ClPoisonStack; | |||
994 | PoisonUndef = SanitizeFunction && ClPoisonUndef; | |||
995 | // FIXME: Consider using SpecialCaseList to specify a list of functions that | |||
996 | // must always return fully initialized values. For now, we hardcode "main". | |||
997 | CheckReturnValue = SanitizeFunction && (F.getName() == "main"); | |||
998 | TLI = &MS.getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(); | |||
999 | ||||
1000 | MS.initializeCallbacks(*F.getParent()); | |||
1001 | if (MS.CompileKernel) | |||
1002 | ActualFnStart = insertKmsanPrologue(F); | |||
1003 | else | |||
1004 | ActualFnStart = &F.getEntryBlock(); | |||
1005 | ||||
1006 | LLVM_DEBUG(if (!InsertChecks) dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { if (!InsertChecks) dbgs() << "MemorySanitizer is not inserting checks into '" << F.getName() << "'\n"; } } while (false) | |||
1007 | << "MemorySanitizer is not inserting checks into '"do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { if (!InsertChecks) dbgs() << "MemorySanitizer is not inserting checks into '" << F.getName() << "'\n"; } } while (false) | |||
1008 | << F.getName() << "'\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { if (!InsertChecks) dbgs() << "MemorySanitizer is not inserting checks into '" << F.getName() << "'\n"; } } while (false); | |||
1009 | } | |||
1010 | ||||
1011 | Value *updateOrigin(Value *V, IRBuilder<> &IRB) { | |||
1012 | if (MS.TrackOrigins <= 1) return V; | |||
1013 | return IRB.CreateCall(MS.MsanChainOriginFn, V); | |||
1014 | } | |||
1015 | ||||
1016 | Value *originToIntptr(IRBuilder<> &IRB, Value *Origin) { | |||
1017 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
1018 | unsigned IntptrSize = DL.getTypeStoreSize(MS.IntptrTy); | |||
1019 | if (IntptrSize == kOriginSize) return Origin; | |||
1020 | assert(IntptrSize == kOriginSize * 2)((IntptrSize == kOriginSize * 2) ? static_cast<void> (0 ) : __assert_fail ("IntptrSize == kOriginSize * 2", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1020, __PRETTY_FUNCTION__)); | |||
1021 | Origin = IRB.CreateIntCast(Origin, MS.IntptrTy, /* isSigned */ false); | |||
1022 | return IRB.CreateOr(Origin, IRB.CreateShl(Origin, kOriginSize * 8)); | |||
1023 | } | |||
1024 | ||||
1025 | /// Fill memory range with the given origin value. | |||
1026 | void paintOrigin(IRBuilder<> &IRB, Value *Origin, Value *OriginPtr, | |||
1027 | unsigned Size, unsigned Alignment) { | |||
1028 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
1029 | unsigned IntptrAlignment = DL.getABITypeAlignment(MS.IntptrTy); | |||
1030 | unsigned IntptrSize = DL.getTypeStoreSize(MS.IntptrTy); | |||
1031 | assert(IntptrAlignment >= kMinOriginAlignment)((IntptrAlignment >= kMinOriginAlignment) ? static_cast< void> (0) : __assert_fail ("IntptrAlignment >= kMinOriginAlignment" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1031, __PRETTY_FUNCTION__)); | |||
1032 | assert(IntptrSize >= kOriginSize)((IntptrSize >= kOriginSize) ? static_cast<void> (0) : __assert_fail ("IntptrSize >= kOriginSize", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1032, __PRETTY_FUNCTION__)); | |||
1033 | ||||
1034 | unsigned Ofs = 0; | |||
1035 | unsigned CurrentAlignment = Alignment; | |||
1036 | if (Alignment >= IntptrAlignment && IntptrSize > kOriginSize) { | |||
1037 | Value *IntptrOrigin = originToIntptr(IRB, Origin); | |||
1038 | Value *IntptrOriginPtr = | |||
1039 | IRB.CreatePointerCast(OriginPtr, PointerType::get(MS.IntptrTy, 0)); | |||
1040 | for (unsigned i = 0; i < Size / IntptrSize; ++i) { | |||
1041 | Value *Ptr = i ? IRB.CreateConstGEP1_32(MS.IntptrTy, IntptrOriginPtr, i) | |||
1042 | : IntptrOriginPtr; | |||
1043 | IRB.CreateAlignedStore(IntptrOrigin, Ptr, CurrentAlignment); | |||
1044 | Ofs += IntptrSize / kOriginSize; | |||
1045 | CurrentAlignment = IntptrAlignment; | |||
1046 | } | |||
1047 | } | |||
1048 | ||||
1049 | for (unsigned i = Ofs; i < (Size + kOriginSize - 1) / kOriginSize; ++i) { | |||
1050 | Value *GEP = | |||
1051 | i ? IRB.CreateConstGEP1_32(nullptr, OriginPtr, i) : OriginPtr; | |||
1052 | IRB.CreateAlignedStore(Origin, GEP, CurrentAlignment); | |||
1053 | CurrentAlignment = kMinOriginAlignment; | |||
1054 | } | |||
1055 | } | |||
1056 | ||||
1057 | void storeOrigin(IRBuilder<> &IRB, Value *Addr, Value *Shadow, Value *Origin, | |||
1058 | Value *OriginPtr, unsigned Alignment, bool AsCall) { | |||
1059 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
1060 | unsigned OriginAlignment = std::max(kMinOriginAlignment, Alignment); | |||
1061 | unsigned StoreSize = DL.getTypeStoreSize(Shadow->getType()); | |||
1062 | if (Shadow->getType()->isAggregateType()) { | |||
1063 | paintOrigin(IRB, updateOrigin(Origin, IRB), OriginPtr, StoreSize, | |||
1064 | OriginAlignment); | |||
1065 | } else { | |||
1066 | Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB); | |||
1067 | Constant *ConstantShadow = dyn_cast_or_null<Constant>(ConvertedShadow); | |||
1068 | if (ConstantShadow) { | |||
1069 | if (ClCheckConstantShadow && !ConstantShadow->isZeroValue()) | |||
1070 | paintOrigin(IRB, updateOrigin(Origin, IRB), OriginPtr, StoreSize, | |||
1071 | OriginAlignment); | |||
1072 | return; | |||
1073 | } | |||
1074 | ||||
1075 | unsigned TypeSizeInBits = | |||
1076 | DL.getTypeSizeInBits(ConvertedShadow->getType()); | |||
1077 | unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits); | |||
1078 | if (AsCall && SizeIndex < kNumberOfAccessSizes && !MS.CompileKernel) { | |||
1079 | Value *Fn = MS.MaybeStoreOriginFn[SizeIndex]; | |||
1080 | Value *ConvertedShadow2 = IRB.CreateZExt( | |||
1081 | ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex))); | |||
1082 | IRB.CreateCall(Fn, {ConvertedShadow2, | |||
1083 | IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()), | |||
1084 | Origin}); | |||
1085 | } else { | |||
1086 | Value *Cmp = IRB.CreateICmpNE( | |||
1087 | ConvertedShadow, getCleanShadow(ConvertedShadow), "_mscmp"); | |||
1088 | Instruction *CheckTerm = SplitBlockAndInsertIfThen( | |||
1089 | Cmp, &*IRB.GetInsertPoint(), false, MS.OriginStoreWeights); | |||
1090 | IRBuilder<> IRBNew(CheckTerm); | |||
1091 | paintOrigin(IRBNew, updateOrigin(Origin, IRBNew), OriginPtr, StoreSize, | |||
1092 | OriginAlignment); | |||
1093 | } | |||
1094 | } | |||
1095 | } | |||
1096 | ||||
1097 | void materializeStores(bool InstrumentWithCalls) { | |||
1098 | for (StoreInst *SI : StoreList) { | |||
1099 | IRBuilder<> IRB(SI); | |||
1100 | Value *Val = SI->getValueOperand(); | |||
1101 | Value *Addr = SI->getPointerOperand(); | |||
1102 | Value *Shadow = SI->isAtomic() ? getCleanShadow(Val) : getShadow(Val); | |||
1103 | Value *ShadowPtr, *OriginPtr; | |||
1104 | Type *ShadowTy = Shadow->getType(); | |||
1105 | unsigned Alignment = SI->getAlignment(); | |||
1106 | unsigned OriginAlignment = std::max(kMinOriginAlignment, Alignment); | |||
1107 | std::tie(ShadowPtr, OriginPtr) = | |||
1108 | getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ true); | |||
1109 | ||||
1110 | StoreInst *NewSI = IRB.CreateAlignedStore(Shadow, ShadowPtr, Alignment); | |||
1111 | LLVM_DEBUG(dbgs() << " STORE: " << *NewSI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " STORE: " << *NewSI << "\n"; } } while (false); | |||
1112 | (void)NewSI; | |||
1113 | ||||
1114 | if (SI->isAtomic()) | |||
1115 | SI->setOrdering(addReleaseOrdering(SI->getOrdering())); | |||
1116 | ||||
1117 | if (MS.TrackOrigins && !SI->isAtomic()) | |||
1118 | storeOrigin(IRB, Addr, Shadow, getOrigin(Val), OriginPtr, | |||
1119 | OriginAlignment, InstrumentWithCalls); | |||
1120 | } | |||
1121 | } | |||
1122 | ||||
1123 | /// Helper function to insert a warning at IRB's current insert point. | |||
1124 | void insertWarningFn(IRBuilder<> &IRB, Value *Origin) { | |||
1125 | if (!Origin) | |||
1126 | Origin = (Value *)IRB.getInt32(0); | |||
1127 | if (MS.CompileKernel) { | |||
1128 | IRB.CreateCall(MS.WarningFn, Origin); | |||
1129 | } else { | |||
1130 | if (MS.TrackOrigins) { | |||
1131 | IRB.CreateStore(Origin, MS.OriginTLS); | |||
1132 | } | |||
1133 | IRB.CreateCall(MS.WarningFn, {}); | |||
1134 | } | |||
1135 | IRB.CreateCall(MS.EmptyAsm, {}); | |||
1136 | // FIXME: Insert UnreachableInst if !MS.Recover? | |||
1137 | // This may invalidate some of the following checks and needs to be done | |||
1138 | // at the very end. | |||
1139 | } | |||
1140 | ||||
1141 | void materializeOneCheck(Instruction *OrigIns, Value *Shadow, Value *Origin, | |||
1142 | bool AsCall) { | |||
1143 | IRBuilder<> IRB(OrigIns); | |||
1144 | LLVM_DEBUG(dbgs() << " SHAD0 : " << *Shadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " SHAD0 : " << *Shadow << "\n"; } } while (false); | |||
1145 | Value *ConvertedShadow = convertToShadowTyNoVec(Shadow, IRB); | |||
1146 | LLVM_DEBUG(dbgs() << " SHAD1 : " << *ConvertedShadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " SHAD1 : " << *ConvertedShadow << "\n"; } } while (false); | |||
1147 | ||||
1148 | Constant *ConstantShadow = dyn_cast_or_null<Constant>(ConvertedShadow); | |||
1149 | if (ConstantShadow) { | |||
1150 | if (ClCheckConstantShadow && !ConstantShadow->isZeroValue()) { | |||
1151 | insertWarningFn(IRB, Origin); | |||
1152 | } | |||
1153 | return; | |||
1154 | } | |||
1155 | ||||
1156 | const DataLayout &DL = OrigIns->getModule()->getDataLayout(); | |||
1157 | ||||
1158 | unsigned TypeSizeInBits = DL.getTypeSizeInBits(ConvertedShadow->getType()); | |||
1159 | unsigned SizeIndex = TypeSizeToSizeIndex(TypeSizeInBits); | |||
1160 | if (AsCall && SizeIndex < kNumberOfAccessSizes && !MS.CompileKernel) { | |||
1161 | Value *Fn = MS.MaybeWarningFn[SizeIndex]; | |||
1162 | Value *ConvertedShadow2 = | |||
1163 | IRB.CreateZExt(ConvertedShadow, IRB.getIntNTy(8 * (1 << SizeIndex))); | |||
1164 | IRB.CreateCall(Fn, {ConvertedShadow2, MS.TrackOrigins && Origin | |||
1165 | ? Origin | |||
1166 | : (Value *)IRB.getInt32(0)}); | |||
1167 | } else { | |||
1168 | Value *Cmp = IRB.CreateICmpNE(ConvertedShadow, | |||
1169 | getCleanShadow(ConvertedShadow), "_mscmp"); | |||
1170 | Instruction *CheckTerm = SplitBlockAndInsertIfThen( | |||
1171 | Cmp, OrigIns, | |||
1172 | /* Unreachable */ !MS.Recover, MS.ColdCallWeights); | |||
1173 | ||||
1174 | IRB.SetInsertPoint(CheckTerm); | |||
1175 | insertWarningFn(IRB, Origin); | |||
1176 | LLVM_DEBUG(dbgs() << " CHECK: " << *Cmp << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " CHECK: " << *Cmp << "\n"; } } while (false); | |||
1177 | } | |||
1178 | } | |||
1179 | ||||
1180 | void materializeChecks(bool InstrumentWithCalls) { | |||
1181 | for (const auto &ShadowData : InstrumentationList) { | |||
1182 | Instruction *OrigIns = ShadowData.OrigIns; | |||
1183 | Value *Shadow = ShadowData.Shadow; | |||
1184 | Value *Origin = ShadowData.Origin; | |||
1185 | materializeOneCheck(OrigIns, Shadow, Origin, InstrumentWithCalls); | |||
1186 | } | |||
1187 | LLVM_DEBUG(dbgs() << "DONE:\n" << F)do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << "DONE:\n" << F; } } while ( false); | |||
1188 | } | |||
1189 | ||||
1190 | BasicBlock *insertKmsanPrologue(Function &F) { | |||
1191 | BasicBlock *ret = | |||
1192 | SplitBlock(&F.getEntryBlock(), F.getEntryBlock().getFirstNonPHI()); | |||
1193 | IRBuilder<> IRB(F.getEntryBlock().getFirstNonPHI()); | |||
1194 | Value *ContextState = IRB.CreateCall(MS.MsanGetContextStateFn, {}); | |||
1195 | Constant *Zero = IRB.getInt32(0); | |||
1196 | MS.ParamTLS = | |||
1197 | IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(0)}, "param_shadow"); | |||
1198 | MS.RetvalTLS = | |||
1199 | IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(1)}, "retval_shadow"); | |||
1200 | MS.VAArgTLS = | |||
1201 | IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(2)}, "va_arg_shadow"); | |||
1202 | MS.VAArgOriginTLS = | |||
1203 | IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(3)}, "va_arg_origin"); | |||
1204 | MS.VAArgOverflowSizeTLS = IRB.CreateGEP( | |||
1205 | ContextState, {Zero, IRB.getInt32(4)}, "va_arg_overflow_size"); | |||
1206 | MS.ParamOriginTLS = | |||
1207 | IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(5)}, "param_origin"); | |||
1208 | MS.RetvalOriginTLS = | |||
1209 | IRB.CreateGEP(ContextState, {Zero, IRB.getInt32(6)}, "retval_origin"); | |||
1210 | return ret; | |||
1211 | } | |||
1212 | ||||
1213 | /// Add MemorySanitizer instrumentation to a function. | |||
1214 | bool runOnFunction() { | |||
1215 | // In the presence of unreachable blocks, we may see Phi nodes with | |||
1216 | // incoming nodes from such blocks. Since InstVisitor skips unreachable | |||
1217 | // blocks, such nodes will not have any shadow value associated with them. | |||
1218 | // It's easier to remove unreachable blocks than deal with missing shadow. | |||
1219 | removeUnreachableBlocks(F); | |||
1220 | ||||
1221 | // Iterate all BBs in depth-first order and create shadow instructions | |||
1222 | // for all instructions (where applicable). | |||
1223 | // For PHI nodes we create dummy shadow PHIs which will be finalized later. | |||
1224 | for (BasicBlock *BB : depth_first(ActualFnStart)) | |||
1225 | visit(*BB); | |||
1226 | ||||
1227 | // Finalize PHI nodes. | |||
1228 | for (PHINode *PN : ShadowPHINodes) { | |||
1229 | PHINode *PNS = cast<PHINode>(getShadow(PN)); | |||
1230 | PHINode *PNO = MS.TrackOrigins ? cast<PHINode>(getOrigin(PN)) : nullptr; | |||
1231 | size_t NumValues = PN->getNumIncomingValues(); | |||
1232 | for (size_t v = 0; v < NumValues; v++) { | |||
1233 | PNS->addIncoming(getShadow(PN, v), PN->getIncomingBlock(v)); | |||
1234 | if (PNO) PNO->addIncoming(getOrigin(PN, v), PN->getIncomingBlock(v)); | |||
1235 | } | |||
1236 | } | |||
1237 | ||||
1238 | VAHelper->finalizeInstrumentation(); | |||
1239 | ||||
1240 | bool InstrumentWithCalls = ClInstrumentationWithCallThreshold >= 0 && | |||
1241 | InstrumentationList.size() + StoreList.size() > | |||
1242 | (unsigned)ClInstrumentationWithCallThreshold; | |||
1243 | ||||
1244 | // Insert shadow value checks. | |||
1245 | materializeChecks(InstrumentWithCalls); | |||
1246 | ||||
1247 | // Delayed instrumentation of StoreInst. | |||
1248 | // This may not add new address checks. | |||
1249 | materializeStores(InstrumentWithCalls); | |||
1250 | ||||
1251 | return true; | |||
1252 | } | |||
1253 | ||||
1254 | /// Compute the shadow type that corresponds to a given Value. | |||
1255 | Type *getShadowTy(Value *V) { | |||
1256 | return getShadowTy(V->getType()); | |||
1257 | } | |||
1258 | ||||
1259 | /// Compute the shadow type that corresponds to a given Type. | |||
1260 | Type *getShadowTy(Type *OrigTy) { | |||
1261 | if (!OrigTy->isSized()) { | |||
1262 | return nullptr; | |||
1263 | } | |||
1264 | // For integer type, shadow is the same as the original type. | |||
1265 | // This may return weird-sized types like i1. | |||
1266 | if (IntegerType *IT = dyn_cast<IntegerType>(OrigTy)) | |||
1267 | return IT; | |||
1268 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
1269 | if (VectorType *VT = dyn_cast<VectorType>(OrigTy)) { | |||
1270 | uint32_t EltSize = DL.getTypeSizeInBits(VT->getElementType()); | |||
1271 | return VectorType::get(IntegerType::get(*MS.C, EltSize), | |||
1272 | VT->getNumElements()); | |||
1273 | } | |||
1274 | if (ArrayType *AT = dyn_cast<ArrayType>(OrigTy)) { | |||
1275 | return ArrayType::get(getShadowTy(AT->getElementType()), | |||
1276 | AT->getNumElements()); | |||
1277 | } | |||
1278 | if (StructType *ST = dyn_cast<StructType>(OrigTy)) { | |||
1279 | SmallVector<Type*, 4> Elements; | |||
1280 | for (unsigned i = 0, n = ST->getNumElements(); i < n; i++) | |||
1281 | Elements.push_back(getShadowTy(ST->getElementType(i))); | |||
1282 | StructType *Res = StructType::get(*MS.C, Elements, ST->isPacked()); | |||
1283 | LLVM_DEBUG(dbgs() << "getShadowTy: " << *ST << " ===> " << *Res << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << "getShadowTy: " << *ST << " ===> " << *Res << "\n"; } } while (false); | |||
1284 | return Res; | |||
1285 | } | |||
1286 | uint32_t TypeSize = DL.getTypeSizeInBits(OrigTy); | |||
1287 | return IntegerType::get(*MS.C, TypeSize); | |||
1288 | } | |||
1289 | ||||
1290 | /// Flatten a vector type. | |||
1291 | Type *getShadowTyNoVec(Type *ty) { | |||
1292 | if (VectorType *vt = dyn_cast<VectorType>(ty)) | |||
1293 | return IntegerType::get(*MS.C, vt->getBitWidth()); | |||
1294 | return ty; | |||
1295 | } | |||
1296 | ||||
1297 | /// Convert a shadow value to it's flattened variant. | |||
1298 | Value *convertToShadowTyNoVec(Value *V, IRBuilder<> &IRB) { | |||
1299 | Type *Ty = V->getType(); | |||
1300 | Type *NoVecTy = getShadowTyNoVec(Ty); | |||
1301 | if (Ty == NoVecTy) return V; | |||
1302 | return IRB.CreateBitCast(V, NoVecTy); | |||
1303 | } | |||
1304 | ||||
1305 | /// Compute the integer shadow offset that corresponds to a given | |||
1306 | /// application address. | |||
1307 | /// | |||
1308 | /// Offset = (Addr & ~AndMask) ^ XorMask | |||
1309 | Value *getShadowPtrOffset(Value *Addr, IRBuilder<> &IRB) { | |||
1310 | Value *OffsetLong = IRB.CreatePointerCast(Addr, MS.IntptrTy); | |||
1311 | ||||
1312 | uint64_t AndMask = MS.MapParams->AndMask; | |||
1313 | if (AndMask) | |||
1314 | OffsetLong = | |||
1315 | IRB.CreateAnd(OffsetLong, ConstantInt::get(MS.IntptrTy, ~AndMask)); | |||
1316 | ||||
1317 | uint64_t XorMask = MS.MapParams->XorMask; | |||
1318 | if (XorMask) | |||
1319 | OffsetLong = | |||
1320 | IRB.CreateXor(OffsetLong, ConstantInt::get(MS.IntptrTy, XorMask)); | |||
1321 | return OffsetLong; | |||
1322 | } | |||
1323 | ||||
1324 | /// Compute the shadow and origin addresses corresponding to a given | |||
1325 | /// application address. | |||
1326 | /// | |||
1327 | /// Shadow = ShadowBase + Offset | |||
1328 | /// Origin = (OriginBase + Offset) & ~3ULL | |||
1329 | std::pair<Value *, Value *> getShadowOriginPtrUserspace(Value *Addr, | |||
1330 | IRBuilder<> &IRB, | |||
1331 | Type *ShadowTy, | |||
1332 | unsigned Alignment) { | |||
1333 | Value *ShadowOffset = getShadowPtrOffset(Addr, IRB); | |||
1334 | Value *ShadowLong = ShadowOffset; | |||
1335 | uint64_t ShadowBase = MS.MapParams->ShadowBase; | |||
1336 | if (ShadowBase != 0) { | |||
1337 | ShadowLong = | |||
1338 | IRB.CreateAdd(ShadowLong, | |||
1339 | ConstantInt::get(MS.IntptrTy, ShadowBase)); | |||
1340 | } | |||
1341 | Value *ShadowPtr = | |||
1342 | IRB.CreateIntToPtr(ShadowLong, PointerType::get(ShadowTy, 0)); | |||
1343 | Value *OriginPtr = nullptr; | |||
1344 | if (MS.TrackOrigins) { | |||
1345 | Value *OriginLong = ShadowOffset; | |||
1346 | uint64_t OriginBase = MS.MapParams->OriginBase; | |||
1347 | if (OriginBase != 0) | |||
1348 | OriginLong = IRB.CreateAdd(OriginLong, | |||
1349 | ConstantInt::get(MS.IntptrTy, OriginBase)); | |||
1350 | if (Alignment < kMinOriginAlignment) { | |||
1351 | uint64_t Mask = kMinOriginAlignment - 1; | |||
1352 | OriginLong = | |||
1353 | IRB.CreateAnd(OriginLong, ConstantInt::get(MS.IntptrTy, ~Mask)); | |||
1354 | } | |||
1355 | OriginPtr = | |||
1356 | IRB.CreateIntToPtr(OriginLong, PointerType::get(IRB.getInt32Ty(), 0)); | |||
1357 | } | |||
1358 | return std::make_pair(ShadowPtr, OriginPtr); | |||
1359 | } | |||
1360 | ||||
1361 | std::pair<Value *, Value *> | |||
1362 | getShadowOriginPtrKernel(Value *Addr, IRBuilder<> &IRB, Type *ShadowTy, | |||
1363 | unsigned Alignment, bool isStore) { | |||
1364 | Value *ShadowOriginPtrs; | |||
1365 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
1366 | int Size = DL.getTypeStoreSize(ShadowTy); | |||
1367 | ||||
1368 | Value *Getter = MS.getKmsanShadowOriginAccessFn(isStore, Size); | |||
1369 | Value *AddrCast = | |||
1370 | IRB.CreatePointerCast(Addr, PointerType::get(IRB.getInt8Ty(), 0)); | |||
1371 | if (Getter) { | |||
1372 | ShadowOriginPtrs = IRB.CreateCall(Getter, AddrCast); | |||
1373 | } else { | |||
1374 | Value *SizeVal = ConstantInt::get(MS.IntptrTy, Size); | |||
1375 | ShadowOriginPtrs = IRB.CreateCall(isStore ? MS.MsanMetadataPtrForStoreN | |||
1376 | : MS.MsanMetadataPtrForLoadN, | |||
1377 | {AddrCast, SizeVal}); | |||
1378 | } | |||
1379 | Value *ShadowPtr = IRB.CreateExtractValue(ShadowOriginPtrs, 0); | |||
1380 | ShadowPtr = IRB.CreatePointerCast(ShadowPtr, PointerType::get(ShadowTy, 0)); | |||
1381 | Value *OriginPtr = IRB.CreateExtractValue(ShadowOriginPtrs, 1); | |||
1382 | ||||
1383 | return std::make_pair(ShadowPtr, OriginPtr); | |||
1384 | } | |||
1385 | ||||
1386 | std::pair<Value *, Value *> getShadowOriginPtr(Value *Addr, IRBuilder<> &IRB, | |||
1387 | Type *ShadowTy, | |||
1388 | unsigned Alignment, | |||
1389 | bool isStore) { | |||
1390 | std::pair<Value *, Value *> ret; | |||
1391 | if (MS.CompileKernel) | |||
1392 | ret = getShadowOriginPtrKernel(Addr, IRB, ShadowTy, Alignment, isStore); | |||
1393 | else | |||
1394 | ret = getShadowOriginPtrUserspace(Addr, IRB, ShadowTy, Alignment); | |||
1395 | return ret; | |||
1396 | } | |||
1397 | ||||
1398 | /// Compute the shadow address for a given function argument. | |||
1399 | /// | |||
1400 | /// Shadow = ParamTLS+ArgOffset. | |||
1401 | Value *getShadowPtrForArgument(Value *A, IRBuilder<> &IRB, | |||
1402 | int ArgOffset) { | |||
1403 | Value *Base = IRB.CreatePointerCast(MS.ParamTLS, MS.IntptrTy); | |||
1404 | if (ArgOffset) | |||
1405 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
1406 | return IRB.CreateIntToPtr(Base, PointerType::get(getShadowTy(A), 0), | |||
1407 | "_msarg"); | |||
1408 | } | |||
1409 | ||||
1410 | /// Compute the origin address for a given function argument. | |||
1411 | Value *getOriginPtrForArgument(Value *A, IRBuilder<> &IRB, | |||
1412 | int ArgOffset) { | |||
1413 | if (!MS.TrackOrigins) | |||
1414 | return nullptr; | |||
1415 | Value *Base = IRB.CreatePointerCast(MS.ParamOriginTLS, MS.IntptrTy); | |||
1416 | if (ArgOffset) | |||
1417 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
1418 | return IRB.CreateIntToPtr(Base, PointerType::get(MS.OriginTy, 0), | |||
1419 | "_msarg_o"); | |||
1420 | } | |||
1421 | ||||
1422 | /// Compute the shadow address for a retval. | |||
1423 | Value *getShadowPtrForRetval(Value *A, IRBuilder<> &IRB) { | |||
1424 | return IRB.CreatePointerCast(MS.RetvalTLS, | |||
1425 | PointerType::get(getShadowTy(A), 0), | |||
1426 | "_msret"); | |||
1427 | } | |||
1428 | ||||
1429 | /// Compute the origin address for a retval. | |||
1430 | Value *getOriginPtrForRetval(IRBuilder<> &IRB) { | |||
1431 | // We keep a single origin for the entire retval. Might be too optimistic. | |||
1432 | return MS.RetvalOriginTLS; | |||
1433 | } | |||
1434 | ||||
1435 | /// Set SV to be the shadow value for V. | |||
1436 | void setShadow(Value *V, Value *SV) { | |||
1437 | assert(!ShadowMap.count(V) && "Values may only have one shadow")((!ShadowMap.count(V) && "Values may only have one shadow" ) ? static_cast<void> (0) : __assert_fail ("!ShadowMap.count(V) && \"Values may only have one shadow\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1437, __PRETTY_FUNCTION__)); | |||
1438 | ShadowMap[V] = PropagateShadow ? SV : getCleanShadow(V); | |||
1439 | } | |||
1440 | ||||
1441 | /// Set Origin to be the origin value for V. | |||
1442 | void setOrigin(Value *V, Value *Origin) { | |||
1443 | if (!MS.TrackOrigins) return; | |||
1444 | assert(!OriginMap.count(V) && "Values may only have one origin")((!OriginMap.count(V) && "Values may only have one origin" ) ? static_cast<void> (0) : __assert_fail ("!OriginMap.count(V) && \"Values may only have one origin\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1444, __PRETTY_FUNCTION__)); | |||
1445 | LLVM_DEBUG(dbgs() << "ORIGIN: " << *V << " ==> " << *Origin << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << "ORIGIN: " << *V << " ==> " << *Origin << "\n"; } } while (false); | |||
1446 | OriginMap[V] = Origin; | |||
1447 | } | |||
1448 | ||||
1449 | Constant *getCleanShadow(Type *OrigTy) { | |||
1450 | Type *ShadowTy = getShadowTy(OrigTy); | |||
1451 | if (!ShadowTy) | |||
1452 | return nullptr; | |||
1453 | return Constant::getNullValue(ShadowTy); | |||
1454 | } | |||
1455 | ||||
1456 | /// Create a clean shadow value for a given value. | |||
1457 | /// | |||
1458 | /// Clean shadow (all zeroes) means all bits of the value are defined | |||
1459 | /// (initialized). | |||
1460 | Constant *getCleanShadow(Value *V) { | |||
1461 | return getCleanShadow(V->getType()); | |||
1462 | } | |||
1463 | ||||
1464 | /// Create a dirty shadow of a given shadow type. | |||
1465 | Constant *getPoisonedShadow(Type *ShadowTy) { | |||
1466 | assert(ShadowTy)((ShadowTy) ? static_cast<void> (0) : __assert_fail ("ShadowTy" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1466, __PRETTY_FUNCTION__)); | |||
1467 | if (isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy)) | |||
1468 | return Constant::getAllOnesValue(ShadowTy); | |||
1469 | if (ArrayType *AT = dyn_cast<ArrayType>(ShadowTy)) { | |||
1470 | SmallVector<Constant *, 4> Vals(AT->getNumElements(), | |||
1471 | getPoisonedShadow(AT->getElementType())); | |||
1472 | return ConstantArray::get(AT, Vals); | |||
1473 | } | |||
1474 | if (StructType *ST = dyn_cast<StructType>(ShadowTy)) { | |||
1475 | SmallVector<Constant *, 4> Vals; | |||
1476 | for (unsigned i = 0, n = ST->getNumElements(); i < n; i++) | |||
1477 | Vals.push_back(getPoisonedShadow(ST->getElementType(i))); | |||
1478 | return ConstantStruct::get(ST, Vals); | |||
1479 | } | |||
1480 | llvm_unreachable("Unexpected shadow type")::llvm::llvm_unreachable_internal("Unexpected shadow type", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1480); | |||
1481 | } | |||
1482 | ||||
1483 | /// Create a dirty shadow for a given value. | |||
1484 | Constant *getPoisonedShadow(Value *V) { | |||
1485 | Type *ShadowTy = getShadowTy(V); | |||
1486 | if (!ShadowTy) | |||
1487 | return nullptr; | |||
1488 | return getPoisonedShadow(ShadowTy); | |||
1489 | } | |||
1490 | ||||
1491 | /// Create a clean (zero) origin. | |||
1492 | Value *getCleanOrigin() { | |||
1493 | return Constant::getNullValue(MS.OriginTy); | |||
1494 | } | |||
1495 | ||||
1496 | /// Get the shadow value for a given Value. | |||
1497 | /// | |||
1498 | /// This function either returns the value set earlier with setShadow, | |||
1499 | /// or extracts if from ParamTLS (for function arguments). | |||
1500 | Value *getShadow(Value *V) { | |||
1501 | if (!PropagateShadow) return getCleanShadow(V); | |||
1502 | if (Instruction *I = dyn_cast<Instruction>(V)) { | |||
1503 | if (I->getMetadata("nosanitize")) | |||
1504 | return getCleanShadow(V); | |||
1505 | // For instructions the shadow is already stored in the map. | |||
1506 | Value *Shadow = ShadowMap[V]; | |||
1507 | if (!Shadow) { | |||
1508 | LLVM_DEBUG(dbgs() << "No shadow: " << *V << "\n" << *(I->getParent()))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << "No shadow: " << *V << "\n" << *(I->getParent()); } } while (false); | |||
1509 | (void)I; | |||
1510 | assert(Shadow && "No shadow for a value")((Shadow && "No shadow for a value") ? static_cast< void> (0) : __assert_fail ("Shadow && \"No shadow for a value\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1510, __PRETTY_FUNCTION__)); | |||
1511 | } | |||
1512 | return Shadow; | |||
1513 | } | |||
1514 | if (UndefValue *U = dyn_cast<UndefValue>(V)) { | |||
1515 | Value *AllOnes = PoisonUndef ? getPoisonedShadow(V) : getCleanShadow(V); | |||
1516 | LLVM_DEBUG(dbgs() << "Undef: " << *U << " ==> " << *AllOnes << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << "Undef: " << *U << " ==> " << *AllOnes << "\n"; } } while (false); | |||
1517 | (void)U; | |||
1518 | return AllOnes; | |||
1519 | } | |||
1520 | if (Argument *A = dyn_cast<Argument>(V)) { | |||
1521 | // For arguments we compute the shadow on demand and store it in the map. | |||
1522 | Value **ShadowPtr = &ShadowMap[V]; | |||
1523 | if (*ShadowPtr) | |||
1524 | return *ShadowPtr; | |||
1525 | Function *F = A->getParent(); | |||
1526 | IRBuilder<> EntryIRB(ActualFnStart->getFirstNonPHI()); | |||
1527 | unsigned ArgOffset = 0; | |||
1528 | const DataLayout &DL = F->getParent()->getDataLayout(); | |||
1529 | for (auto &FArg : F->args()) { | |||
1530 | if (!FArg.getType()->isSized()) { | |||
1531 | LLVM_DEBUG(dbgs() << "Arg is not sized\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << "Arg is not sized\n"; } } while ( false); | |||
1532 | continue; | |||
1533 | } | |||
1534 | unsigned Size = | |||
1535 | FArg.hasByValAttr() | |||
1536 | ? DL.getTypeAllocSize(FArg.getType()->getPointerElementType()) | |||
1537 | : DL.getTypeAllocSize(FArg.getType()); | |||
1538 | if (A == &FArg) { | |||
1539 | bool Overflow = ArgOffset + Size > kParamTLSSize; | |||
1540 | Value *Base = getShadowPtrForArgument(&FArg, EntryIRB, ArgOffset); | |||
1541 | if (FArg.hasByValAttr()) { | |||
1542 | // ByVal pointer itself has clean shadow. We copy the actual | |||
1543 | // argument shadow to the underlying memory. | |||
1544 | // Figure out maximal valid memcpy alignment. | |||
1545 | unsigned ArgAlign = FArg.getParamAlignment(); | |||
1546 | if (ArgAlign == 0) { | |||
1547 | Type *EltType = A->getType()->getPointerElementType(); | |||
1548 | ArgAlign = DL.getABITypeAlignment(EltType); | |||
1549 | } | |||
1550 | Value *CpShadowPtr = | |||
1551 | getShadowOriginPtr(V, EntryIRB, EntryIRB.getInt8Ty(), ArgAlign, | |||
1552 | /*isStore*/ true) | |||
1553 | .first; | |||
1554 | // TODO(glider): need to copy origins. | |||
1555 | if (Overflow) { | |||
1556 | // ParamTLS overflow. | |||
1557 | EntryIRB.CreateMemSet( | |||
1558 | CpShadowPtr, Constant::getNullValue(EntryIRB.getInt8Ty()), | |||
1559 | Size, ArgAlign); | |||
1560 | } else { | |||
1561 | unsigned CopyAlign = std::min(ArgAlign, kShadowTLSAlignment); | |||
1562 | Value *Cpy = EntryIRB.CreateMemCpy(CpShadowPtr, CopyAlign, Base, | |||
1563 | CopyAlign, Size); | |||
1564 | LLVM_DEBUG(dbgs() << " ByValCpy: " << *Cpy << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " ByValCpy: " << *Cpy << "\n"; } } while (false); | |||
1565 | (void)Cpy; | |||
1566 | } | |||
1567 | *ShadowPtr = getCleanShadow(V); | |||
1568 | } else { | |||
1569 | if (Overflow) { | |||
1570 | // ParamTLS overflow. | |||
1571 | *ShadowPtr = getCleanShadow(V); | |||
1572 | } else { | |||
1573 | *ShadowPtr = | |||
1574 | EntryIRB.CreateAlignedLoad(Base, kShadowTLSAlignment); | |||
1575 | } | |||
1576 | } | |||
1577 | LLVM_DEBUG(dbgs()do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " ARG: " << FArg << " ==> " << **ShadowPtr << "\n"; } } while (false ) | |||
1578 | << " ARG: " << FArg << " ==> " << **ShadowPtr << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " ARG: " << FArg << " ==> " << **ShadowPtr << "\n"; } } while (false ); | |||
1579 | if (MS.TrackOrigins && !Overflow) { | |||
1580 | Value *OriginPtr = | |||
1581 | getOriginPtrForArgument(&FArg, EntryIRB, ArgOffset); | |||
1582 | setOrigin(A, EntryIRB.CreateLoad(OriginPtr)); | |||
1583 | } else { | |||
1584 | setOrigin(A, getCleanOrigin()); | |||
1585 | } | |||
1586 | } | |||
1587 | ArgOffset += alignTo(Size, kShadowTLSAlignment); | |||
1588 | } | |||
1589 | assert(*ShadowPtr && "Could not find shadow for an argument")((*ShadowPtr && "Could not find shadow for an argument" ) ? static_cast<void> (0) : __assert_fail ("*ShadowPtr && \"Could not find shadow for an argument\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1589, __PRETTY_FUNCTION__)); | |||
1590 | return *ShadowPtr; | |||
1591 | } | |||
1592 | // For everything else the shadow is zero. | |||
1593 | return getCleanShadow(V); | |||
1594 | } | |||
1595 | ||||
1596 | /// Get the shadow for i-th argument of the instruction I. | |||
1597 | Value *getShadow(Instruction *I, int i) { | |||
1598 | return getShadow(I->getOperand(i)); | |||
1599 | } | |||
1600 | ||||
1601 | /// Get the origin for a value. | |||
1602 | Value *getOrigin(Value *V) { | |||
1603 | if (!MS.TrackOrigins) return nullptr; | |||
1604 | if (!PropagateShadow) return getCleanOrigin(); | |||
1605 | if (isa<Constant>(V)) return getCleanOrigin(); | |||
1606 | assert((isa<Instruction>(V) || isa<Argument>(V)) &&(((isa<Instruction>(V) || isa<Argument>(V)) && "Unexpected value type in getOrigin()") ? static_cast<void > (0) : __assert_fail ("(isa<Instruction>(V) || isa<Argument>(V)) && \"Unexpected value type in getOrigin()\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1607, __PRETTY_FUNCTION__)) | |||
1607 | "Unexpected value type in getOrigin()")(((isa<Instruction>(V) || isa<Argument>(V)) && "Unexpected value type in getOrigin()") ? static_cast<void > (0) : __assert_fail ("(isa<Instruction>(V) || isa<Argument>(V)) && \"Unexpected value type in getOrigin()\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1607, __PRETTY_FUNCTION__)); | |||
1608 | if (Instruction *I = dyn_cast<Instruction>(V)) { | |||
1609 | if (I->getMetadata("nosanitize")) | |||
1610 | return getCleanOrigin(); | |||
1611 | } | |||
1612 | Value *Origin = OriginMap[V]; | |||
1613 | assert(Origin && "Missing origin")((Origin && "Missing origin") ? static_cast<void> (0) : __assert_fail ("Origin && \"Missing origin\"", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1613, __PRETTY_FUNCTION__)); | |||
1614 | return Origin; | |||
1615 | } | |||
1616 | ||||
1617 | /// Get the origin for i-th argument of the instruction I. | |||
1618 | Value *getOrigin(Instruction *I, int i) { | |||
1619 | return getOrigin(I->getOperand(i)); | |||
1620 | } | |||
1621 | ||||
1622 | /// Remember the place where a shadow check should be inserted. | |||
1623 | /// | |||
1624 | /// This location will be later instrumented with a check that will print a | |||
1625 | /// UMR warning in runtime if the shadow value is not 0. | |||
1626 | void insertShadowCheck(Value *Shadow, Value *Origin, Instruction *OrigIns) { | |||
1627 | assert(Shadow)((Shadow) ? static_cast<void> (0) : __assert_fail ("Shadow" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1627, __PRETTY_FUNCTION__)); | |||
1628 | if (!InsertChecks) return; | |||
1629 | #ifndef NDEBUG | |||
1630 | Type *ShadowTy = Shadow->getType(); | |||
1631 | assert((isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy)) &&(((isa<IntegerType>(ShadowTy) || isa<VectorType>( ShadowTy)) && "Can only insert checks for integer and vector shadow types" ) ? static_cast<void> (0) : __assert_fail ("(isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy)) && \"Can only insert checks for integer and vector shadow types\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1632, __PRETTY_FUNCTION__)) | |||
1632 | "Can only insert checks for integer and vector shadow types")(((isa<IntegerType>(ShadowTy) || isa<VectorType>( ShadowTy)) && "Can only insert checks for integer and vector shadow types" ) ? static_cast<void> (0) : __assert_fail ("(isa<IntegerType>(ShadowTy) || isa<VectorType>(ShadowTy)) && \"Can only insert checks for integer and vector shadow types\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1632, __PRETTY_FUNCTION__)); | |||
1633 | #endif | |||
1634 | InstrumentationList.push_back( | |||
1635 | ShadowOriginAndInsertPoint(Shadow, Origin, OrigIns)); | |||
1636 | } | |||
1637 | ||||
1638 | /// Remember the place where a shadow check should be inserted. | |||
1639 | /// | |||
1640 | /// This location will be later instrumented with a check that will print a | |||
1641 | /// UMR warning in runtime if the value is not fully defined. | |||
1642 | void insertShadowCheck(Value *Val, Instruction *OrigIns) { | |||
1643 | assert(Val)((Val) ? static_cast<void> (0) : __assert_fail ("Val", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1643, __PRETTY_FUNCTION__)); | |||
1644 | Value *Shadow, *Origin; | |||
1645 | if (ClCheckConstantShadow) { | |||
1646 | Shadow = getShadow(Val); | |||
1647 | if (!Shadow) return; | |||
1648 | Origin = getOrigin(Val); | |||
1649 | } else { | |||
1650 | Shadow = dyn_cast_or_null<Instruction>(getShadow(Val)); | |||
1651 | if (!Shadow) return; | |||
1652 | Origin = dyn_cast_or_null<Instruction>(getOrigin(Val)); | |||
1653 | } | |||
1654 | insertShadowCheck(Shadow, Origin, OrigIns); | |||
1655 | } | |||
1656 | ||||
1657 | AtomicOrdering addReleaseOrdering(AtomicOrdering a) { | |||
1658 | switch (a) { | |||
1659 | case AtomicOrdering::NotAtomic: | |||
1660 | return AtomicOrdering::NotAtomic; | |||
1661 | case AtomicOrdering::Unordered: | |||
1662 | case AtomicOrdering::Monotonic: | |||
1663 | case AtomicOrdering::Release: | |||
1664 | return AtomicOrdering::Release; | |||
1665 | case AtomicOrdering::Acquire: | |||
1666 | case AtomicOrdering::AcquireRelease: | |||
1667 | return AtomicOrdering::AcquireRelease; | |||
1668 | case AtomicOrdering::SequentiallyConsistent: | |||
1669 | return AtomicOrdering::SequentiallyConsistent; | |||
1670 | } | |||
1671 | llvm_unreachable("Unknown ordering")::llvm::llvm_unreachable_internal("Unknown ordering", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1671); | |||
1672 | } | |||
1673 | ||||
1674 | AtomicOrdering addAcquireOrdering(AtomicOrdering a) { | |||
1675 | switch (a) { | |||
1676 | case AtomicOrdering::NotAtomic: | |||
1677 | return AtomicOrdering::NotAtomic; | |||
1678 | case AtomicOrdering::Unordered: | |||
1679 | case AtomicOrdering::Monotonic: | |||
1680 | case AtomicOrdering::Acquire: | |||
1681 | return AtomicOrdering::Acquire; | |||
1682 | case AtomicOrdering::Release: | |||
1683 | case AtomicOrdering::AcquireRelease: | |||
1684 | return AtomicOrdering::AcquireRelease; | |||
1685 | case AtomicOrdering::SequentiallyConsistent: | |||
1686 | return AtomicOrdering::SequentiallyConsistent; | |||
1687 | } | |||
1688 | llvm_unreachable("Unknown ordering")::llvm::llvm_unreachable_internal("Unknown ordering", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1688); | |||
1689 | } | |||
1690 | ||||
1691 | // ------------------- Visitors. | |||
1692 | using InstVisitor<MemorySanitizerVisitor>::visit; | |||
1693 | void visit(Instruction &I) { | |||
1694 | if (!I.getMetadata("nosanitize")) | |||
1695 | InstVisitor<MemorySanitizerVisitor>::visit(I); | |||
1696 | } | |||
1697 | ||||
1698 | /// Instrument LoadInst | |||
1699 | /// | |||
1700 | /// Loads the corresponding shadow and (optionally) origin. | |||
1701 | /// Optionally, checks that the load address is fully defined. | |||
1702 | void visitLoadInst(LoadInst &I) { | |||
1703 | assert(I.getType()->isSized() && "Load type must have size")((I.getType()->isSized() && "Load type must have size" ) ? static_cast<void> (0) : __assert_fail ("I.getType()->isSized() && \"Load type must have size\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1703, __PRETTY_FUNCTION__)); | |||
1704 | assert(!I.getMetadata("nosanitize"))((!I.getMetadata("nosanitize")) ? static_cast<void> (0) : __assert_fail ("!I.getMetadata(\"nosanitize\")", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1704, __PRETTY_FUNCTION__)); | |||
1705 | IRBuilder<> IRB(I.getNextNode()); | |||
1706 | Type *ShadowTy = getShadowTy(&I); | |||
1707 | Value *Addr = I.getPointerOperand(); | |||
1708 | Value *ShadowPtr, *OriginPtr; | |||
1709 | unsigned Alignment = I.getAlignment(); | |||
1710 | if (PropagateShadow) { | |||
1711 | std::tie(ShadowPtr, OriginPtr) = | |||
1712 | getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ false); | |||
1713 | setShadow(&I, IRB.CreateAlignedLoad(ShadowPtr, Alignment, "_msld")); | |||
1714 | } else { | |||
1715 | setShadow(&I, getCleanShadow(&I)); | |||
1716 | } | |||
1717 | ||||
1718 | if (ClCheckAccessAddress) | |||
1719 | insertShadowCheck(I.getPointerOperand(), &I); | |||
1720 | ||||
1721 | if (I.isAtomic()) | |||
1722 | I.setOrdering(addAcquireOrdering(I.getOrdering())); | |||
1723 | ||||
1724 | if (MS.TrackOrigins) { | |||
1725 | if (PropagateShadow) { | |||
1726 | unsigned OriginAlignment = std::max(kMinOriginAlignment, Alignment); | |||
1727 | setOrigin(&I, IRB.CreateAlignedLoad(OriginPtr, OriginAlignment)); | |||
1728 | } else { | |||
1729 | setOrigin(&I, getCleanOrigin()); | |||
1730 | } | |||
1731 | } | |||
1732 | } | |||
1733 | ||||
1734 | /// Instrument StoreInst | |||
1735 | /// | |||
1736 | /// Stores the corresponding shadow and (optionally) origin. | |||
1737 | /// Optionally, checks that the store address is fully defined. | |||
1738 | void visitStoreInst(StoreInst &I) { | |||
1739 | StoreList.push_back(&I); | |||
1740 | if (ClCheckAccessAddress) | |||
1741 | insertShadowCheck(I.getPointerOperand(), &I); | |||
1742 | } | |||
1743 | ||||
1744 | void handleCASOrRMW(Instruction &I) { | |||
1745 | assert(isa<AtomicRMWInst>(I) || isa<AtomicCmpXchgInst>(I))((isa<AtomicRMWInst>(I) || isa<AtomicCmpXchgInst> (I)) ? static_cast<void> (0) : __assert_fail ("isa<AtomicRMWInst>(I) || isa<AtomicCmpXchgInst>(I)" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1745, __PRETTY_FUNCTION__)); | |||
1746 | ||||
1747 | IRBuilder<> IRB(&I); | |||
1748 | Value *Addr = I.getOperand(0); | |||
1749 | Value *ShadowPtr = getShadowOriginPtr(Addr, IRB, I.getType(), | |||
1750 | /*Alignment*/ 1, /*isStore*/ true) | |||
1751 | .first; | |||
1752 | ||||
1753 | if (ClCheckAccessAddress) | |||
1754 | insertShadowCheck(Addr, &I); | |||
1755 | ||||
1756 | // Only test the conditional argument of cmpxchg instruction. | |||
1757 | // The other argument can potentially be uninitialized, but we can not | |||
1758 | // detect this situation reliably without possible false positives. | |||
1759 | if (isa<AtomicCmpXchgInst>(I)) | |||
1760 | insertShadowCheck(I.getOperand(1), &I); | |||
1761 | ||||
1762 | IRB.CreateStore(getCleanShadow(&I), ShadowPtr); | |||
1763 | ||||
1764 | setShadow(&I, getCleanShadow(&I)); | |||
1765 | setOrigin(&I, getCleanOrigin()); | |||
1766 | } | |||
1767 | ||||
1768 | void visitAtomicRMWInst(AtomicRMWInst &I) { | |||
1769 | handleCASOrRMW(I); | |||
1770 | I.setOrdering(addReleaseOrdering(I.getOrdering())); | |||
1771 | } | |||
1772 | ||||
1773 | void visitAtomicCmpXchgInst(AtomicCmpXchgInst &I) { | |||
1774 | handleCASOrRMW(I); | |||
1775 | I.setSuccessOrdering(addReleaseOrdering(I.getSuccessOrdering())); | |||
1776 | } | |||
1777 | ||||
1778 | // Vector manipulation. | |||
1779 | void visitExtractElementInst(ExtractElementInst &I) { | |||
1780 | insertShadowCheck(I.getOperand(1), &I); | |||
1781 | IRBuilder<> IRB(&I); | |||
1782 | setShadow(&I, IRB.CreateExtractElement(getShadow(&I, 0), I.getOperand(1), | |||
1783 | "_msprop")); | |||
1784 | setOrigin(&I, getOrigin(&I, 0)); | |||
1785 | } | |||
1786 | ||||
1787 | void visitInsertElementInst(InsertElementInst &I) { | |||
1788 | insertShadowCheck(I.getOperand(2), &I); | |||
1789 | IRBuilder<> IRB(&I); | |||
1790 | setShadow(&I, IRB.CreateInsertElement(getShadow(&I, 0), getShadow(&I, 1), | |||
1791 | I.getOperand(2), "_msprop")); | |||
1792 | setOriginForNaryOp(I); | |||
1793 | } | |||
1794 | ||||
1795 | void visitShuffleVectorInst(ShuffleVectorInst &I) { | |||
1796 | insertShadowCheck(I.getOperand(2), &I); | |||
1797 | IRBuilder<> IRB(&I); | |||
1798 | setShadow(&I, IRB.CreateShuffleVector(getShadow(&I, 0), getShadow(&I, 1), | |||
1799 | I.getOperand(2), "_msprop")); | |||
1800 | setOriginForNaryOp(I); | |||
1801 | } | |||
1802 | ||||
1803 | // Casts. | |||
1804 | void visitSExtInst(SExtInst &I) { | |||
1805 | IRBuilder<> IRB(&I); | |||
1806 | setShadow(&I, IRB.CreateSExt(getShadow(&I, 0), I.getType(), "_msprop")); | |||
1807 | setOrigin(&I, getOrigin(&I, 0)); | |||
1808 | } | |||
1809 | ||||
1810 | void visitZExtInst(ZExtInst &I) { | |||
1811 | IRBuilder<> IRB(&I); | |||
1812 | setShadow(&I, IRB.CreateZExt(getShadow(&I, 0), I.getType(), "_msprop")); | |||
1813 | setOrigin(&I, getOrigin(&I, 0)); | |||
1814 | } | |||
1815 | ||||
1816 | void visitTruncInst(TruncInst &I) { | |||
1817 | IRBuilder<> IRB(&I); | |||
1818 | setShadow(&I, IRB.CreateTrunc(getShadow(&I, 0), I.getType(), "_msprop")); | |||
1819 | setOrigin(&I, getOrigin(&I, 0)); | |||
1820 | } | |||
1821 | ||||
1822 | void visitBitCastInst(BitCastInst &I) { | |||
1823 | // Special case: if this is the bitcast (there is exactly 1 allowed) between | |||
1824 | // a musttail call and a ret, don't instrument. New instructions are not | |||
1825 | // allowed after a musttail call. | |||
1826 | if (auto *CI = dyn_cast<CallInst>(I.getOperand(0))) | |||
1827 | if (CI->isMustTailCall()) | |||
1828 | return; | |||
1829 | IRBuilder<> IRB(&I); | |||
1830 | setShadow(&I, IRB.CreateBitCast(getShadow(&I, 0), getShadowTy(&I))); | |||
1831 | setOrigin(&I, getOrigin(&I, 0)); | |||
1832 | } | |||
1833 | ||||
1834 | void visitPtrToIntInst(PtrToIntInst &I) { | |||
1835 | IRBuilder<> IRB(&I); | |||
1836 | setShadow(&I, IRB.CreateIntCast(getShadow(&I, 0), getShadowTy(&I), false, | |||
1837 | "_msprop_ptrtoint")); | |||
1838 | setOrigin(&I, getOrigin(&I, 0)); | |||
1839 | } | |||
1840 | ||||
1841 | void visitIntToPtrInst(IntToPtrInst &I) { | |||
1842 | IRBuilder<> IRB(&I); | |||
1843 | setShadow(&I, IRB.CreateIntCast(getShadow(&I, 0), getShadowTy(&I), false, | |||
1844 | "_msprop_inttoptr")); | |||
1845 | setOrigin(&I, getOrigin(&I, 0)); | |||
1846 | } | |||
1847 | ||||
1848 | void visitFPToSIInst(CastInst& I) { handleShadowOr(I); } | |||
1849 | void visitFPToUIInst(CastInst& I) { handleShadowOr(I); } | |||
1850 | void visitSIToFPInst(CastInst& I) { handleShadowOr(I); } | |||
1851 | void visitUIToFPInst(CastInst& I) { handleShadowOr(I); } | |||
1852 | void visitFPExtInst(CastInst& I) { handleShadowOr(I); } | |||
1853 | void visitFPTruncInst(CastInst& I) { handleShadowOr(I); } | |||
1854 | ||||
1855 | /// Propagate shadow for bitwise AND. | |||
1856 | /// | |||
1857 | /// This code is exact, i.e. if, for example, a bit in the left argument | |||
1858 | /// is defined and 0, then neither the value not definedness of the | |||
1859 | /// corresponding bit in B don't affect the resulting shadow. | |||
1860 | void visitAnd(BinaryOperator &I) { | |||
1861 | IRBuilder<> IRB(&I); | |||
1862 | // "And" of 0 and a poisoned value results in unpoisoned value. | |||
1863 | // 1&1 => 1; 0&1 => 0; p&1 => p; | |||
1864 | // 1&0 => 0; 0&0 => 0; p&0 => 0; | |||
1865 | // 1&p => p; 0&p => 0; p&p => p; | |||
1866 | // S = (S1 & S2) | (V1 & S2) | (S1 & V2) | |||
1867 | Value *S1 = getShadow(&I, 0); | |||
1868 | Value *S2 = getShadow(&I, 1); | |||
1869 | Value *V1 = I.getOperand(0); | |||
1870 | Value *V2 = I.getOperand(1); | |||
1871 | if (V1->getType() != S1->getType()) { | |||
1872 | V1 = IRB.CreateIntCast(V1, S1->getType(), false); | |||
1873 | V2 = IRB.CreateIntCast(V2, S2->getType(), false); | |||
1874 | } | |||
1875 | Value *S1S2 = IRB.CreateAnd(S1, S2); | |||
1876 | Value *V1S2 = IRB.CreateAnd(V1, S2); | |||
1877 | Value *S1V2 = IRB.CreateAnd(S1, V2); | |||
1878 | setShadow(&I, IRB.CreateOr(S1S2, IRB.CreateOr(V1S2, S1V2))); | |||
1879 | setOriginForNaryOp(I); | |||
1880 | } | |||
1881 | ||||
1882 | void visitOr(BinaryOperator &I) { | |||
1883 | IRBuilder<> IRB(&I); | |||
1884 | // "Or" of 1 and a poisoned value results in unpoisoned value. | |||
1885 | // 1|1 => 1; 0|1 => 1; p|1 => 1; | |||
1886 | // 1|0 => 1; 0|0 => 0; p|0 => p; | |||
1887 | // 1|p => 1; 0|p => p; p|p => p; | |||
1888 | // S = (S1 & S2) | (~V1 & S2) | (S1 & ~V2) | |||
1889 | Value *S1 = getShadow(&I, 0); | |||
1890 | Value *S2 = getShadow(&I, 1); | |||
1891 | Value *V1 = IRB.CreateNot(I.getOperand(0)); | |||
1892 | Value *V2 = IRB.CreateNot(I.getOperand(1)); | |||
1893 | if (V1->getType() != S1->getType()) { | |||
1894 | V1 = IRB.CreateIntCast(V1, S1->getType(), false); | |||
1895 | V2 = IRB.CreateIntCast(V2, S2->getType(), false); | |||
1896 | } | |||
1897 | Value *S1S2 = IRB.CreateAnd(S1, S2); | |||
1898 | Value *V1S2 = IRB.CreateAnd(V1, S2); | |||
1899 | Value *S1V2 = IRB.CreateAnd(S1, V2); | |||
1900 | setShadow(&I, IRB.CreateOr(S1S2, IRB.CreateOr(V1S2, S1V2))); | |||
1901 | setOriginForNaryOp(I); | |||
1902 | } | |||
1903 | ||||
1904 | /// Default propagation of shadow and/or origin. | |||
1905 | /// | |||
1906 | /// This class implements the general case of shadow propagation, used in all | |||
1907 | /// cases where we don't know and/or don't care about what the operation | |||
1908 | /// actually does. It converts all input shadow values to a common type | |||
1909 | /// (extending or truncating as necessary), and bitwise OR's them. | |||
1910 | /// | |||
1911 | /// This is much cheaper than inserting checks (i.e. requiring inputs to be | |||
1912 | /// fully initialized), and less prone to false positives. | |||
1913 | /// | |||
1914 | /// This class also implements the general case of origin propagation. For a | |||
1915 | /// Nary operation, result origin is set to the origin of an argument that is | |||
1916 | /// not entirely initialized. If there is more than one such arguments, the | |||
1917 | /// rightmost of them is picked. It does not matter which one is picked if all | |||
1918 | /// arguments are initialized. | |||
1919 | template <bool CombineShadow> | |||
1920 | class Combiner { | |||
1921 | Value *Shadow = nullptr; | |||
1922 | Value *Origin = nullptr; | |||
1923 | IRBuilder<> &IRB; | |||
1924 | MemorySanitizerVisitor *MSV; | |||
1925 | ||||
1926 | public: | |||
1927 | Combiner(MemorySanitizerVisitor *MSV, IRBuilder<> &IRB) | |||
1928 | : IRB(IRB), MSV(MSV) {} | |||
1929 | ||||
1930 | /// Add a pair of shadow and origin values to the mix. | |||
1931 | Combiner &Add(Value *OpShadow, Value *OpOrigin) { | |||
1932 | if (CombineShadow) { | |||
1933 | assert(OpShadow)((OpShadow) ? static_cast<void> (0) : __assert_fail ("OpShadow" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1933, __PRETTY_FUNCTION__)); | |||
1934 | if (!Shadow) | |||
1935 | Shadow = OpShadow; | |||
1936 | else { | |||
1937 | OpShadow = MSV->CreateShadowCast(IRB, OpShadow, Shadow->getType()); | |||
1938 | Shadow = IRB.CreateOr(Shadow, OpShadow, "_msprop"); | |||
1939 | } | |||
1940 | } | |||
1941 | ||||
1942 | if (MSV->MS.TrackOrigins) { | |||
1943 | assert(OpOrigin)((OpOrigin) ? static_cast<void> (0) : __assert_fail ("OpOrigin" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1943, __PRETTY_FUNCTION__)); | |||
1944 | if (!Origin) { | |||
1945 | Origin = OpOrigin; | |||
1946 | } else { | |||
1947 | Constant *ConstOrigin = dyn_cast<Constant>(OpOrigin); | |||
1948 | // No point in adding something that might result in 0 origin value. | |||
1949 | if (!ConstOrigin || !ConstOrigin->isNullValue()) { | |||
1950 | Value *FlatShadow = MSV->convertToShadowTyNoVec(OpShadow, IRB); | |||
1951 | Value *Cond = | |||
1952 | IRB.CreateICmpNE(FlatShadow, MSV->getCleanShadow(FlatShadow)); | |||
1953 | Origin = IRB.CreateSelect(Cond, OpOrigin, Origin); | |||
1954 | } | |||
1955 | } | |||
1956 | } | |||
1957 | return *this; | |||
1958 | } | |||
1959 | ||||
1960 | /// Add an application value to the mix. | |||
1961 | Combiner &Add(Value *V) { | |||
1962 | Value *OpShadow = MSV->getShadow(V); | |||
1963 | Value *OpOrigin = MSV->MS.TrackOrigins ? MSV->getOrigin(V) : nullptr; | |||
1964 | return Add(OpShadow, OpOrigin); | |||
1965 | } | |||
1966 | ||||
1967 | /// Set the current combined values as the given instruction's shadow | |||
1968 | /// and origin. | |||
1969 | void Done(Instruction *I) { | |||
1970 | if (CombineShadow) { | |||
1971 | assert(Shadow)((Shadow) ? static_cast<void> (0) : __assert_fail ("Shadow" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1971, __PRETTY_FUNCTION__)); | |||
1972 | Shadow = MSV->CreateShadowCast(IRB, Shadow, MSV->getShadowTy(I)); | |||
1973 | MSV->setShadow(I, Shadow); | |||
1974 | } | |||
1975 | if (MSV->MS.TrackOrigins) { | |||
1976 | assert(Origin)((Origin) ? static_cast<void> (0) : __assert_fail ("Origin" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1976, __PRETTY_FUNCTION__)); | |||
1977 | MSV->setOrigin(I, Origin); | |||
1978 | } | |||
1979 | } | |||
1980 | }; | |||
1981 | ||||
1982 | using ShadowAndOriginCombiner = Combiner<true>; | |||
1983 | using OriginCombiner = Combiner<false>; | |||
1984 | ||||
1985 | /// Propagate origin for arbitrary operation. | |||
1986 | void setOriginForNaryOp(Instruction &I) { | |||
1987 | if (!MS.TrackOrigins) return; | |||
1988 | IRBuilder<> IRB(&I); | |||
1989 | OriginCombiner OC(this, IRB); | |||
1990 | for (Instruction::op_iterator OI = I.op_begin(); OI != I.op_end(); ++OI) | |||
1991 | OC.Add(OI->get()); | |||
1992 | OC.Done(&I); | |||
1993 | } | |||
1994 | ||||
1995 | size_t VectorOrPrimitiveTypeSizeInBits(Type *Ty) { | |||
1996 | assert(!(Ty->isVectorTy() && Ty->getScalarType()->isPointerTy()) &&((!(Ty->isVectorTy() && Ty->getScalarType()-> isPointerTy()) && "Vector of pointers is not a valid shadow type" ) ? static_cast<void> (0) : __assert_fail ("!(Ty->isVectorTy() && Ty->getScalarType()->isPointerTy()) && \"Vector of pointers is not a valid shadow type\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1997, __PRETTY_FUNCTION__)) | |||
1997 | "Vector of pointers is not a valid shadow type")((!(Ty->isVectorTy() && Ty->getScalarType()-> isPointerTy()) && "Vector of pointers is not a valid shadow type" ) ? static_cast<void> (0) : __assert_fail ("!(Ty->isVectorTy() && Ty->getScalarType()->isPointerTy()) && \"Vector of pointers is not a valid shadow type\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 1997, __PRETTY_FUNCTION__)); | |||
1998 | return Ty->isVectorTy() ? | |||
1999 | Ty->getVectorNumElements() * Ty->getScalarSizeInBits() : | |||
2000 | Ty->getPrimitiveSizeInBits(); | |||
2001 | } | |||
2002 | ||||
2003 | /// Cast between two shadow types, extending or truncating as | |||
2004 | /// necessary. | |||
2005 | Value *CreateShadowCast(IRBuilder<> &IRB, Value *V, Type *dstTy, | |||
2006 | bool Signed = false) { | |||
2007 | Type *srcTy = V->getType(); | |||
2008 | size_t srcSizeInBits = VectorOrPrimitiveTypeSizeInBits(srcTy); | |||
2009 | size_t dstSizeInBits = VectorOrPrimitiveTypeSizeInBits(dstTy); | |||
2010 | if (srcSizeInBits > 1 && dstSizeInBits == 1) | |||
2011 | return IRB.CreateICmpNE(V, getCleanShadow(V)); | |||
2012 | ||||
2013 | if (dstTy->isIntegerTy() && srcTy->isIntegerTy()) | |||
2014 | return IRB.CreateIntCast(V, dstTy, Signed); | |||
2015 | if (dstTy->isVectorTy() && srcTy->isVectorTy() && | |||
2016 | dstTy->getVectorNumElements() == srcTy->getVectorNumElements()) | |||
2017 | return IRB.CreateIntCast(V, dstTy, Signed); | |||
2018 | Value *V1 = IRB.CreateBitCast(V, Type::getIntNTy(*MS.C, srcSizeInBits)); | |||
2019 | Value *V2 = | |||
2020 | IRB.CreateIntCast(V1, Type::getIntNTy(*MS.C, dstSizeInBits), Signed); | |||
2021 | return IRB.CreateBitCast(V2, dstTy); | |||
2022 | // TODO: handle struct types. | |||
2023 | } | |||
2024 | ||||
2025 | /// Cast an application value to the type of its own shadow. | |||
2026 | Value *CreateAppToShadowCast(IRBuilder<> &IRB, Value *V) { | |||
2027 | Type *ShadowTy = getShadowTy(V); | |||
2028 | if (V->getType() == ShadowTy) | |||
2029 | return V; | |||
2030 | if (V->getType()->isPtrOrPtrVectorTy()) | |||
2031 | return IRB.CreatePtrToInt(V, ShadowTy); | |||
2032 | else | |||
2033 | return IRB.CreateBitCast(V, ShadowTy); | |||
2034 | } | |||
2035 | ||||
2036 | /// Propagate shadow for arbitrary operation. | |||
2037 | void handleShadowOr(Instruction &I) { | |||
2038 | IRBuilder<> IRB(&I); | |||
2039 | ShadowAndOriginCombiner SC(this, IRB); | |||
2040 | for (Instruction::op_iterator OI = I.op_begin(); OI != I.op_end(); ++OI) | |||
2041 | SC.Add(OI->get()); | |||
2042 | SC.Done(&I); | |||
2043 | } | |||
2044 | ||||
2045 | // Handle multiplication by constant. | |||
2046 | // | |||
2047 | // Handle a special case of multiplication by constant that may have one or | |||
2048 | // more zeros in the lower bits. This makes corresponding number of lower bits | |||
2049 | // of the result zero as well. We model it by shifting the other operand | |||
2050 | // shadow left by the required number of bits. Effectively, we transform | |||
2051 | // (X * (A * 2**B)) to ((X << B) * A) and instrument (X << B) as (Sx << B). | |||
2052 | // We use multiplication by 2**N instead of shift to cover the case of | |||
2053 | // multiplication by 0, which may occur in some elements of a vector operand. | |||
2054 | void handleMulByConstant(BinaryOperator &I, Constant *ConstArg, | |||
2055 | Value *OtherArg) { | |||
2056 | Constant *ShadowMul; | |||
2057 | Type *Ty = ConstArg->getType(); | |||
2058 | if (Ty->isVectorTy()) { | |||
2059 | unsigned NumElements = Ty->getVectorNumElements(); | |||
2060 | Type *EltTy = Ty->getSequentialElementType(); | |||
2061 | SmallVector<Constant *, 16> Elements; | |||
2062 | for (unsigned Idx = 0; Idx < NumElements; ++Idx) { | |||
2063 | if (ConstantInt *Elt = | |||
2064 | dyn_cast<ConstantInt>(ConstArg->getAggregateElement(Idx))) { | |||
2065 | const APInt &V = Elt->getValue(); | |||
2066 | APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros(); | |||
2067 | Elements.push_back(ConstantInt::get(EltTy, V2)); | |||
2068 | } else { | |||
2069 | Elements.push_back(ConstantInt::get(EltTy, 1)); | |||
2070 | } | |||
2071 | } | |||
2072 | ShadowMul = ConstantVector::get(Elements); | |||
2073 | } else { | |||
2074 | if (ConstantInt *Elt = dyn_cast<ConstantInt>(ConstArg)) { | |||
2075 | const APInt &V = Elt->getValue(); | |||
2076 | APInt V2 = APInt(V.getBitWidth(), 1) << V.countTrailingZeros(); | |||
2077 | ShadowMul = ConstantInt::get(Ty, V2); | |||
2078 | } else { | |||
2079 | ShadowMul = ConstantInt::get(Ty, 1); | |||
2080 | } | |||
2081 | } | |||
2082 | ||||
2083 | IRBuilder<> IRB(&I); | |||
2084 | setShadow(&I, | |||
2085 | IRB.CreateMul(getShadow(OtherArg), ShadowMul, "msprop_mul_cst")); | |||
2086 | setOrigin(&I, getOrigin(OtherArg)); | |||
2087 | } | |||
2088 | ||||
2089 | void visitMul(BinaryOperator &I) { | |||
2090 | Constant *constOp0 = dyn_cast<Constant>(I.getOperand(0)); | |||
2091 | Constant *constOp1 = dyn_cast<Constant>(I.getOperand(1)); | |||
2092 | if (constOp0 && !constOp1) | |||
2093 | handleMulByConstant(I, constOp0, I.getOperand(1)); | |||
2094 | else if (constOp1 && !constOp0) | |||
2095 | handleMulByConstant(I, constOp1, I.getOperand(0)); | |||
2096 | else | |||
2097 | handleShadowOr(I); | |||
2098 | } | |||
2099 | ||||
2100 | void visitFAdd(BinaryOperator &I) { handleShadowOr(I); } | |||
2101 | void visitFSub(BinaryOperator &I) { handleShadowOr(I); } | |||
2102 | void visitFMul(BinaryOperator &I) { handleShadowOr(I); } | |||
2103 | void visitAdd(BinaryOperator &I) { handleShadowOr(I); } | |||
2104 | void visitSub(BinaryOperator &I) { handleShadowOr(I); } | |||
2105 | void visitXor(BinaryOperator &I) { handleShadowOr(I); } | |||
2106 | ||||
2107 | void handleIntegerDiv(Instruction &I) { | |||
2108 | IRBuilder<> IRB(&I); | |||
2109 | // Strict on the second argument. | |||
2110 | insertShadowCheck(I.getOperand(1), &I); | |||
2111 | setShadow(&I, getShadow(&I, 0)); | |||
2112 | setOrigin(&I, getOrigin(&I, 0)); | |||
2113 | } | |||
2114 | ||||
2115 | void visitUDiv(BinaryOperator &I) { handleIntegerDiv(I); } | |||
2116 | void visitSDiv(BinaryOperator &I) { handleIntegerDiv(I); } | |||
2117 | void visitURem(BinaryOperator &I) { handleIntegerDiv(I); } | |||
2118 | void visitSRem(BinaryOperator &I) { handleIntegerDiv(I); } | |||
2119 | ||||
2120 | // Floating point division is side-effect free. We can not require that the | |||
2121 | // divisor is fully initialized and must propagate shadow. See PR37523. | |||
2122 | void visitFDiv(BinaryOperator &I) { handleShadowOr(I); } | |||
2123 | void visitFRem(BinaryOperator &I) { handleShadowOr(I); } | |||
2124 | ||||
2125 | /// Instrument == and != comparisons. | |||
2126 | /// | |||
2127 | /// Sometimes the comparison result is known even if some of the bits of the | |||
2128 | /// arguments are not. | |||
2129 | void handleEqualityComparison(ICmpInst &I) { | |||
2130 | IRBuilder<> IRB(&I); | |||
2131 | Value *A = I.getOperand(0); | |||
2132 | Value *B = I.getOperand(1); | |||
2133 | Value *Sa = getShadow(A); | |||
2134 | Value *Sb = getShadow(B); | |||
2135 | ||||
2136 | // Get rid of pointers and vectors of pointers. | |||
2137 | // For ints (and vectors of ints), types of A and Sa match, | |||
2138 | // and this is a no-op. | |||
2139 | A = IRB.CreatePointerCast(A, Sa->getType()); | |||
2140 | B = IRB.CreatePointerCast(B, Sb->getType()); | |||
2141 | ||||
2142 | // A == B <==> (C = A^B) == 0 | |||
2143 | // A != B <==> (C = A^B) != 0 | |||
2144 | // Sc = Sa | Sb | |||
2145 | Value *C = IRB.CreateXor(A, B); | |||
2146 | Value *Sc = IRB.CreateOr(Sa, Sb); | |||
2147 | // Now dealing with i = (C == 0) comparison (or C != 0, does not matter now) | |||
2148 | // Result is defined if one of the following is true | |||
2149 | // * there is a defined 1 bit in C | |||
2150 | // * C is fully defined | |||
2151 | // Si = !(C & ~Sc) && Sc | |||
2152 | Value *Zero = Constant::getNullValue(Sc->getType()); | |||
2153 | Value *MinusOne = Constant::getAllOnesValue(Sc->getType()); | |||
2154 | Value *Si = | |||
2155 | IRB.CreateAnd(IRB.CreateICmpNE(Sc, Zero), | |||
2156 | IRB.CreateICmpEQ( | |||
2157 | IRB.CreateAnd(IRB.CreateXor(Sc, MinusOne), C), Zero)); | |||
2158 | Si->setName("_msprop_icmp"); | |||
2159 | setShadow(&I, Si); | |||
2160 | setOriginForNaryOp(I); | |||
2161 | } | |||
2162 | ||||
2163 | /// Build the lowest possible value of V, taking into account V's | |||
2164 | /// uninitialized bits. | |||
2165 | Value *getLowestPossibleValue(IRBuilder<> &IRB, Value *A, Value *Sa, | |||
2166 | bool isSigned) { | |||
2167 | if (isSigned) { | |||
2168 | // Split shadow into sign bit and other bits. | |||
2169 | Value *SaOtherBits = IRB.CreateLShr(IRB.CreateShl(Sa, 1), 1); | |||
2170 | Value *SaSignBit = IRB.CreateXor(Sa, SaOtherBits); | |||
2171 | // Maximise the undefined shadow bit, minimize other undefined bits. | |||
2172 | return | |||
2173 | IRB.CreateOr(IRB.CreateAnd(A, IRB.CreateNot(SaOtherBits)), SaSignBit); | |||
2174 | } else { | |||
2175 | // Minimize undefined bits. | |||
2176 | return IRB.CreateAnd(A, IRB.CreateNot(Sa)); | |||
2177 | } | |||
2178 | } | |||
2179 | ||||
2180 | /// Build the highest possible value of V, taking into account V's | |||
2181 | /// uninitialized bits. | |||
2182 | Value *getHighestPossibleValue(IRBuilder<> &IRB, Value *A, Value *Sa, | |||
2183 | bool isSigned) { | |||
2184 | if (isSigned) { | |||
2185 | // Split shadow into sign bit and other bits. | |||
2186 | Value *SaOtherBits = IRB.CreateLShr(IRB.CreateShl(Sa, 1), 1); | |||
2187 | Value *SaSignBit = IRB.CreateXor(Sa, SaOtherBits); | |||
2188 | // Minimise the undefined shadow bit, maximise other undefined bits. | |||
2189 | return | |||
2190 | IRB.CreateOr(IRB.CreateAnd(A, IRB.CreateNot(SaSignBit)), SaOtherBits); | |||
2191 | } else { | |||
2192 | // Maximize undefined bits. | |||
2193 | return IRB.CreateOr(A, Sa); | |||
2194 | } | |||
2195 | } | |||
2196 | ||||
2197 | /// Instrument relational comparisons. | |||
2198 | /// | |||
2199 | /// This function does exact shadow propagation for all relational | |||
2200 | /// comparisons of integers, pointers and vectors of those. | |||
2201 | /// FIXME: output seems suboptimal when one of the operands is a constant | |||
2202 | void handleRelationalComparisonExact(ICmpInst &I) { | |||
2203 | IRBuilder<> IRB(&I); | |||
2204 | Value *A = I.getOperand(0); | |||
2205 | Value *B = I.getOperand(1); | |||
2206 | Value *Sa = getShadow(A); | |||
2207 | Value *Sb = getShadow(B); | |||
2208 | ||||
2209 | // Get rid of pointers and vectors of pointers. | |||
2210 | // For ints (and vectors of ints), types of A and Sa match, | |||
2211 | // and this is a no-op. | |||
2212 | A = IRB.CreatePointerCast(A, Sa->getType()); | |||
2213 | B = IRB.CreatePointerCast(B, Sb->getType()); | |||
2214 | ||||
2215 | // Let [a0, a1] be the interval of possible values of A, taking into account | |||
2216 | // its undefined bits. Let [b0, b1] be the interval of possible values of B. | |||
2217 | // Then (A cmp B) is defined iff (a0 cmp b1) == (a1 cmp b0). | |||
2218 | bool IsSigned = I.isSigned(); | |||
2219 | Value *S1 = IRB.CreateICmp(I.getPredicate(), | |||
2220 | getLowestPossibleValue(IRB, A, Sa, IsSigned), | |||
2221 | getHighestPossibleValue(IRB, B, Sb, IsSigned)); | |||
2222 | Value *S2 = IRB.CreateICmp(I.getPredicate(), | |||
2223 | getHighestPossibleValue(IRB, A, Sa, IsSigned), | |||
2224 | getLowestPossibleValue(IRB, B, Sb, IsSigned)); | |||
2225 | Value *Si = IRB.CreateXor(S1, S2); | |||
2226 | setShadow(&I, Si); | |||
2227 | setOriginForNaryOp(I); | |||
2228 | } | |||
2229 | ||||
2230 | /// Instrument signed relational comparisons. | |||
2231 | /// | |||
2232 | /// Handle sign bit tests: x<0, x>=0, x<=-1, x>-1 by propagating the highest | |||
2233 | /// bit of the shadow. Everything else is delegated to handleShadowOr(). | |||
2234 | void handleSignedRelationalComparison(ICmpInst &I) { | |||
2235 | Constant *constOp; | |||
2236 | Value *op = nullptr; | |||
2237 | CmpInst::Predicate pre; | |||
2238 | if ((constOp = dyn_cast<Constant>(I.getOperand(1)))) { | |||
2239 | op = I.getOperand(0); | |||
2240 | pre = I.getPredicate(); | |||
2241 | } else if ((constOp = dyn_cast<Constant>(I.getOperand(0)))) { | |||
2242 | op = I.getOperand(1); | |||
2243 | pre = I.getSwappedPredicate(); | |||
2244 | } else { | |||
2245 | handleShadowOr(I); | |||
2246 | return; | |||
2247 | } | |||
2248 | ||||
2249 | if ((constOp->isNullValue() && | |||
2250 | (pre == CmpInst::ICMP_SLT || pre == CmpInst::ICMP_SGE)) || | |||
2251 | (constOp->isAllOnesValue() && | |||
2252 | (pre == CmpInst::ICMP_SGT || pre == CmpInst::ICMP_SLE))) { | |||
2253 | IRBuilder<> IRB(&I); | |||
2254 | Value *Shadow = IRB.CreateICmpSLT(getShadow(op), getCleanShadow(op), | |||
2255 | "_msprop_icmp_s"); | |||
2256 | setShadow(&I, Shadow); | |||
2257 | setOrigin(&I, getOrigin(op)); | |||
2258 | } else { | |||
2259 | handleShadowOr(I); | |||
2260 | } | |||
2261 | } | |||
2262 | ||||
2263 | void visitICmpInst(ICmpInst &I) { | |||
2264 | if (!ClHandleICmp) { | |||
2265 | handleShadowOr(I); | |||
2266 | return; | |||
2267 | } | |||
2268 | if (I.isEquality()) { | |||
2269 | handleEqualityComparison(I); | |||
2270 | return; | |||
2271 | } | |||
2272 | ||||
2273 | assert(I.isRelational())((I.isRelational()) ? static_cast<void> (0) : __assert_fail ("I.isRelational()", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 2273, __PRETTY_FUNCTION__)); | |||
2274 | if (ClHandleICmpExact) { | |||
2275 | handleRelationalComparisonExact(I); | |||
2276 | return; | |||
2277 | } | |||
2278 | if (I.isSigned()) { | |||
2279 | handleSignedRelationalComparison(I); | |||
2280 | return; | |||
2281 | } | |||
2282 | ||||
2283 | assert(I.isUnsigned())((I.isUnsigned()) ? static_cast<void> (0) : __assert_fail ("I.isUnsigned()", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 2283, __PRETTY_FUNCTION__)); | |||
2284 | if ((isa<Constant>(I.getOperand(0)) || isa<Constant>(I.getOperand(1)))) { | |||
2285 | handleRelationalComparisonExact(I); | |||
2286 | return; | |||
2287 | } | |||
2288 | ||||
2289 | handleShadowOr(I); | |||
2290 | } | |||
2291 | ||||
2292 | void visitFCmpInst(FCmpInst &I) { | |||
2293 | handleShadowOr(I); | |||
2294 | } | |||
2295 | ||||
2296 | void handleShift(BinaryOperator &I) { | |||
2297 | IRBuilder<> IRB(&I); | |||
2298 | // If any of the S2 bits are poisoned, the whole thing is poisoned. | |||
2299 | // Otherwise perform the same shift on S1. | |||
2300 | Value *S1 = getShadow(&I, 0); | |||
2301 | Value *S2 = getShadow(&I, 1); | |||
2302 | Value *S2Conv = IRB.CreateSExt(IRB.CreateICmpNE(S2, getCleanShadow(S2)), | |||
2303 | S2->getType()); | |||
2304 | Value *V2 = I.getOperand(1); | |||
2305 | Value *Shift = IRB.CreateBinOp(I.getOpcode(), S1, V2); | |||
2306 | setShadow(&I, IRB.CreateOr(Shift, S2Conv)); | |||
2307 | setOriginForNaryOp(I); | |||
2308 | } | |||
2309 | ||||
2310 | void visitShl(BinaryOperator &I) { handleShift(I); } | |||
2311 | void visitAShr(BinaryOperator &I) { handleShift(I); } | |||
2312 | void visitLShr(BinaryOperator &I) { handleShift(I); } | |||
2313 | ||||
2314 | /// Instrument llvm.memmove | |||
2315 | /// | |||
2316 | /// At this point we don't know if llvm.memmove will be inlined or not. | |||
2317 | /// If we don't instrument it and it gets inlined, | |||
2318 | /// our interceptor will not kick in and we will lose the memmove. | |||
2319 | /// If we instrument the call here, but it does not get inlined, | |||
2320 | /// we will memove the shadow twice: which is bad in case | |||
2321 | /// of overlapping regions. So, we simply lower the intrinsic to a call. | |||
2322 | /// | |||
2323 | /// Similar situation exists for memcpy and memset. | |||
2324 | void visitMemMoveInst(MemMoveInst &I) { | |||
2325 | IRBuilder<> IRB(&I); | |||
2326 | IRB.CreateCall( | |||
2327 | MS.MemmoveFn, | |||
2328 | {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()), | |||
2329 | IRB.CreatePointerCast(I.getArgOperand(1), IRB.getInt8PtrTy()), | |||
2330 | IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)}); | |||
2331 | I.eraseFromParent(); | |||
2332 | } | |||
2333 | ||||
2334 | // Similar to memmove: avoid copying shadow twice. | |||
2335 | // This is somewhat unfortunate as it may slowdown small constant memcpys. | |||
2336 | // FIXME: consider doing manual inline for small constant sizes and proper | |||
2337 | // alignment. | |||
2338 | void visitMemCpyInst(MemCpyInst &I) { | |||
2339 | IRBuilder<> IRB(&I); | |||
2340 | IRB.CreateCall( | |||
2341 | MS.MemcpyFn, | |||
2342 | {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()), | |||
2343 | IRB.CreatePointerCast(I.getArgOperand(1), IRB.getInt8PtrTy()), | |||
2344 | IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)}); | |||
2345 | I.eraseFromParent(); | |||
2346 | } | |||
2347 | ||||
2348 | // Same as memcpy. | |||
2349 | void visitMemSetInst(MemSetInst &I) { | |||
2350 | IRBuilder<> IRB(&I); | |||
2351 | IRB.CreateCall( | |||
2352 | MS.MemsetFn, | |||
2353 | {IRB.CreatePointerCast(I.getArgOperand(0), IRB.getInt8PtrTy()), | |||
2354 | IRB.CreateIntCast(I.getArgOperand(1), IRB.getInt32Ty(), false), | |||
2355 | IRB.CreateIntCast(I.getArgOperand(2), MS.IntptrTy, false)}); | |||
2356 | I.eraseFromParent(); | |||
2357 | } | |||
2358 | ||||
2359 | void visitVAStartInst(VAStartInst &I) { | |||
2360 | VAHelper->visitVAStartInst(I); | |||
2361 | } | |||
2362 | ||||
2363 | void visitVACopyInst(VACopyInst &I) { | |||
2364 | VAHelper->visitVACopyInst(I); | |||
2365 | } | |||
2366 | ||||
2367 | /// Handle vector store-like intrinsics. | |||
2368 | /// | |||
2369 | /// Instrument intrinsics that look like a simple SIMD store: writes memory, | |||
2370 | /// has 1 pointer argument and 1 vector argument, returns void. | |||
2371 | bool handleVectorStoreIntrinsic(IntrinsicInst &I) { | |||
2372 | IRBuilder<> IRB(&I); | |||
2373 | Value* Addr = I.getArgOperand(0); | |||
2374 | Value *Shadow = getShadow(&I, 1); | |||
2375 | Value *ShadowPtr, *OriginPtr; | |||
2376 | ||||
2377 | // We don't know the pointer alignment (could be unaligned SSE store!). | |||
2378 | // Have to assume to worst case. | |||
2379 | std::tie(ShadowPtr, OriginPtr) = getShadowOriginPtr( | |||
2380 | Addr, IRB, Shadow->getType(), /*Alignment*/ 1, /*isStore*/ true); | |||
2381 | IRB.CreateAlignedStore(Shadow, ShadowPtr, 1); | |||
2382 | ||||
2383 | if (ClCheckAccessAddress) | |||
2384 | insertShadowCheck(Addr, &I); | |||
2385 | ||||
2386 | // FIXME: factor out common code from materializeStores | |||
2387 | if (MS.TrackOrigins) IRB.CreateStore(getOrigin(&I, 1), OriginPtr); | |||
2388 | return true; | |||
2389 | } | |||
2390 | ||||
2391 | /// Handle vector load-like intrinsics. | |||
2392 | /// | |||
2393 | /// Instrument intrinsics that look like a simple SIMD load: reads memory, | |||
2394 | /// has 1 pointer argument, returns a vector. | |||
2395 | bool handleVectorLoadIntrinsic(IntrinsicInst &I) { | |||
2396 | IRBuilder<> IRB(&I); | |||
2397 | Value *Addr = I.getArgOperand(0); | |||
2398 | ||||
2399 | Type *ShadowTy = getShadowTy(&I); | |||
2400 | Value *ShadowPtr, *OriginPtr; | |||
2401 | if (PropagateShadow) { | |||
2402 | // We don't know the pointer alignment (could be unaligned SSE load!). | |||
2403 | // Have to assume to worst case. | |||
2404 | unsigned Alignment = 1; | |||
2405 | std::tie(ShadowPtr, OriginPtr) = | |||
2406 | getShadowOriginPtr(Addr, IRB, ShadowTy, Alignment, /*isStore*/ false); | |||
2407 | setShadow(&I, IRB.CreateAlignedLoad(ShadowPtr, Alignment, "_msld")); | |||
2408 | } else { | |||
2409 | setShadow(&I, getCleanShadow(&I)); | |||
2410 | } | |||
2411 | ||||
2412 | if (ClCheckAccessAddress) | |||
2413 | insertShadowCheck(Addr, &I); | |||
2414 | ||||
2415 | if (MS.TrackOrigins) { | |||
2416 | if (PropagateShadow) | |||
2417 | setOrigin(&I, IRB.CreateLoad(OriginPtr)); | |||
| ||||
2418 | else | |||
2419 | setOrigin(&I, getCleanOrigin()); | |||
2420 | } | |||
2421 | return true; | |||
2422 | } | |||
2423 | ||||
2424 | /// Handle (SIMD arithmetic)-like intrinsics. | |||
2425 | /// | |||
2426 | /// Instrument intrinsics with any number of arguments of the same type, | |||
2427 | /// equal to the return type. The type should be simple (no aggregates or | |||
2428 | /// pointers; vectors are fine). | |||
2429 | /// Caller guarantees that this intrinsic does not access memory. | |||
2430 | bool maybeHandleSimpleNomemIntrinsic(IntrinsicInst &I) { | |||
2431 | Type *RetTy = I.getType(); | |||
2432 | if (!(RetTy->isIntOrIntVectorTy() || | |||
2433 | RetTy->isFPOrFPVectorTy() || | |||
2434 | RetTy->isX86_MMXTy())) | |||
2435 | return false; | |||
2436 | ||||
2437 | unsigned NumArgOperands = I.getNumArgOperands(); | |||
2438 | ||||
2439 | for (unsigned i = 0; i < NumArgOperands; ++i) { | |||
2440 | Type *Ty = I.getArgOperand(i)->getType(); | |||
2441 | if (Ty != RetTy) | |||
2442 | return false; | |||
2443 | } | |||
2444 | ||||
2445 | IRBuilder<> IRB(&I); | |||
2446 | ShadowAndOriginCombiner SC(this, IRB); | |||
2447 | for (unsigned i = 0; i < NumArgOperands; ++i) | |||
2448 | SC.Add(I.getArgOperand(i)); | |||
2449 | SC.Done(&I); | |||
2450 | ||||
2451 | return true; | |||
2452 | } | |||
2453 | ||||
2454 | /// Heuristically instrument unknown intrinsics. | |||
2455 | /// | |||
2456 | /// The main purpose of this code is to do something reasonable with all | |||
2457 | /// random intrinsics we might encounter, most importantly - SIMD intrinsics. | |||
2458 | /// We recognize several classes of intrinsics by their argument types and | |||
2459 | /// ModRefBehaviour and apply special intrumentation when we are reasonably | |||
2460 | /// sure that we know what the intrinsic does. | |||
2461 | /// | |||
2462 | /// We special-case intrinsics where this approach fails. See llvm.bswap | |||
2463 | /// handling as an example of that. | |||
2464 | bool handleUnknownIntrinsic(IntrinsicInst &I) { | |||
2465 | unsigned NumArgOperands = I.getNumArgOperands(); | |||
2466 | if (NumArgOperands == 0) | |||
2467 | return false; | |||
2468 | ||||
2469 | if (NumArgOperands == 2 && | |||
2470 | I.getArgOperand(0)->getType()->isPointerTy() && | |||
2471 | I.getArgOperand(1)->getType()->isVectorTy() && | |||
2472 | I.getType()->isVoidTy() && | |||
2473 | !I.onlyReadsMemory()) { | |||
2474 | // This looks like a vector store. | |||
2475 | return handleVectorStoreIntrinsic(I); | |||
2476 | } | |||
2477 | ||||
2478 | if (NumArgOperands == 1 && | |||
2479 | I.getArgOperand(0)->getType()->isPointerTy() && | |||
2480 | I.getType()->isVectorTy() && | |||
2481 | I.onlyReadsMemory()) { | |||
2482 | // This looks like a vector load. | |||
2483 | return handleVectorLoadIntrinsic(I); | |||
2484 | } | |||
2485 | ||||
2486 | if (I.doesNotAccessMemory()) | |||
2487 | if (maybeHandleSimpleNomemIntrinsic(I)) | |||
2488 | return true; | |||
2489 | ||||
2490 | // FIXME: detect and handle SSE maskstore/maskload | |||
2491 | return false; | |||
2492 | } | |||
2493 | ||||
2494 | void handleBswap(IntrinsicInst &I) { | |||
2495 | IRBuilder<> IRB(&I); | |||
2496 | Value *Op = I.getArgOperand(0); | |||
2497 | Type *OpType = Op->getType(); | |||
2498 | Function *BswapFunc = Intrinsic::getDeclaration( | |||
2499 | F.getParent(), Intrinsic::bswap, makeArrayRef(&OpType, 1)); | |||
2500 | setShadow(&I, IRB.CreateCall(BswapFunc, getShadow(Op))); | |||
2501 | setOrigin(&I, getOrigin(Op)); | |||
2502 | } | |||
2503 | ||||
2504 | // Instrument vector convert instrinsic. | |||
2505 | // | |||
2506 | // This function instruments intrinsics like cvtsi2ss: | |||
2507 | // %Out = int_xxx_cvtyyy(%ConvertOp) | |||
2508 | // or | |||
2509 | // %Out = int_xxx_cvtyyy(%CopyOp, %ConvertOp) | |||
2510 | // Intrinsic converts \p NumUsedElements elements of \p ConvertOp to the same | |||
2511 | // number \p Out elements, and (if has 2 arguments) copies the rest of the | |||
2512 | // elements from \p CopyOp. | |||
2513 | // In most cases conversion involves floating-point value which may trigger a | |||
2514 | // hardware exception when not fully initialized. For this reason we require | |||
2515 | // \p ConvertOp[0:NumUsedElements] to be fully initialized and trap otherwise. | |||
2516 | // We copy the shadow of \p CopyOp[NumUsedElements:] to \p | |||
2517 | // Out[NumUsedElements:]. This means that intrinsics without \p CopyOp always | |||
2518 | // return a fully initialized value. | |||
2519 | void handleVectorConvertIntrinsic(IntrinsicInst &I, int NumUsedElements) { | |||
2520 | IRBuilder<> IRB(&I); | |||
2521 | Value *CopyOp, *ConvertOp; | |||
2522 | ||||
2523 | switch (I.getNumArgOperands()) { | |||
2524 | case 3: | |||
2525 | assert(isa<ConstantInt>(I.getArgOperand(2)) && "Invalid rounding mode")((isa<ConstantInt>(I.getArgOperand(2)) && "Invalid rounding mode" ) ? static_cast<void> (0) : __assert_fail ("isa<ConstantInt>(I.getArgOperand(2)) && \"Invalid rounding mode\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 2525, __PRETTY_FUNCTION__)); | |||
2526 | LLVM_FALLTHROUGH[[clang::fallthrough]]; | |||
2527 | case 2: | |||
2528 | CopyOp = I.getArgOperand(0); | |||
2529 | ConvertOp = I.getArgOperand(1); | |||
2530 | break; | |||
2531 | case 1: | |||
2532 | ConvertOp = I.getArgOperand(0); | |||
2533 | CopyOp = nullptr; | |||
2534 | break; | |||
2535 | default: | |||
2536 | llvm_unreachable("Cvt intrinsic with unsupported number of arguments.")::llvm::llvm_unreachable_internal("Cvt intrinsic with unsupported number of arguments." , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 2536); | |||
2537 | } | |||
2538 | ||||
2539 | // The first *NumUsedElements* elements of ConvertOp are converted to the | |||
2540 | // same number of output elements. The rest of the output is copied from | |||
2541 | // CopyOp, or (if not available) filled with zeroes. | |||
2542 | // Combine shadow for elements of ConvertOp that are used in this operation, | |||
2543 | // and insert a check. | |||
2544 | // FIXME: consider propagating shadow of ConvertOp, at least in the case of | |||
2545 | // int->any conversion. | |||
2546 | Value *ConvertShadow = getShadow(ConvertOp); | |||
2547 | Value *AggShadow = nullptr; | |||
2548 | if (ConvertOp->getType()->isVectorTy()) { | |||
2549 | AggShadow = IRB.CreateExtractElement( | |||
2550 | ConvertShadow, ConstantInt::get(IRB.getInt32Ty(), 0)); | |||
2551 | for (int i = 1; i < NumUsedElements; ++i) { | |||
2552 | Value *MoreShadow = IRB.CreateExtractElement( | |||
2553 | ConvertShadow, ConstantInt::get(IRB.getInt32Ty(), i)); | |||
2554 | AggShadow = IRB.CreateOr(AggShadow, MoreShadow); | |||
2555 | } | |||
2556 | } else { | |||
2557 | AggShadow = ConvertShadow; | |||
2558 | } | |||
2559 | assert(AggShadow->getType()->isIntegerTy())((AggShadow->getType()->isIntegerTy()) ? static_cast< void> (0) : __assert_fail ("AggShadow->getType()->isIntegerTy()" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 2559, __PRETTY_FUNCTION__)); | |||
2560 | insertShadowCheck(AggShadow, getOrigin(ConvertOp), &I); | |||
2561 | ||||
2562 | // Build result shadow by zero-filling parts of CopyOp shadow that come from | |||
2563 | // ConvertOp. | |||
2564 | if (CopyOp) { | |||
2565 | assert(CopyOp->getType() == I.getType())((CopyOp->getType() == I.getType()) ? static_cast<void> (0) : __assert_fail ("CopyOp->getType() == I.getType()", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 2565, __PRETTY_FUNCTION__)); | |||
2566 | assert(CopyOp->getType()->isVectorTy())((CopyOp->getType()->isVectorTy()) ? static_cast<void > (0) : __assert_fail ("CopyOp->getType()->isVectorTy()" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 2566, __PRETTY_FUNCTION__)); | |||
2567 | Value *ResultShadow = getShadow(CopyOp); | |||
2568 | Type *EltTy = ResultShadow->getType()->getVectorElementType(); | |||
2569 | for (int i = 0; i < NumUsedElements; ++i) { | |||
2570 | ResultShadow = IRB.CreateInsertElement( | |||
2571 | ResultShadow, ConstantInt::getNullValue(EltTy), | |||
2572 | ConstantInt::get(IRB.getInt32Ty(), i)); | |||
2573 | } | |||
2574 | setShadow(&I, ResultShadow); | |||
2575 | setOrigin(&I, getOrigin(CopyOp)); | |||
2576 | } else { | |||
2577 | setShadow(&I, getCleanShadow(&I)); | |||
2578 | setOrigin(&I, getCleanOrigin()); | |||
2579 | } | |||
2580 | } | |||
2581 | ||||
2582 | // Given a scalar or vector, extract lower 64 bits (or less), and return all | |||
2583 | // zeroes if it is zero, and all ones otherwise. | |||
2584 | Value *Lower64ShadowExtend(IRBuilder<> &IRB, Value *S, Type *T) { | |||
2585 | if (S->getType()->isVectorTy()) | |||
2586 | S = CreateShadowCast(IRB, S, IRB.getInt64Ty(), /* Signed */ true); | |||
2587 | assert(S->getType()->getPrimitiveSizeInBits() <= 64)((S->getType()->getPrimitiveSizeInBits() <= 64) ? static_cast <void> (0) : __assert_fail ("S->getType()->getPrimitiveSizeInBits() <= 64" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 2587, __PRETTY_FUNCTION__)); | |||
2588 | Value *S2 = IRB.CreateICmpNE(S, getCleanShadow(S)); | |||
2589 | return CreateShadowCast(IRB, S2, T, /* Signed */ true); | |||
2590 | } | |||
2591 | ||||
2592 | // Given a vector, extract its first element, and return all | |||
2593 | // zeroes if it is zero, and all ones otherwise. | |||
2594 | Value *LowerElementShadowExtend(IRBuilder<> &IRB, Value *S, Type *T) { | |||
2595 | Value *S1 = IRB.CreateExtractElement(S, (uint64_t)0); | |||
2596 | Value *S2 = IRB.CreateICmpNE(S1, getCleanShadow(S1)); | |||
2597 | return CreateShadowCast(IRB, S2, T, /* Signed */ true); | |||
2598 | } | |||
2599 | ||||
2600 | Value *VariableShadowExtend(IRBuilder<> &IRB, Value *S) { | |||
2601 | Type *T = S->getType(); | |||
2602 | assert(T->isVectorTy())((T->isVectorTy()) ? static_cast<void> (0) : __assert_fail ("T->isVectorTy()", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 2602, __PRETTY_FUNCTION__)); | |||
2603 | Value *S2 = IRB.CreateICmpNE(S, getCleanShadow(S)); | |||
2604 | return IRB.CreateSExt(S2, T); | |||
2605 | } | |||
2606 | ||||
2607 | // Instrument vector shift instrinsic. | |||
2608 | // | |||
2609 | // This function instruments intrinsics like int_x86_avx2_psll_w. | |||
2610 | // Intrinsic shifts %In by %ShiftSize bits. | |||
2611 | // %ShiftSize may be a vector. In that case the lower 64 bits determine shift | |||
2612 | // size, and the rest is ignored. Behavior is defined even if shift size is | |||
2613 | // greater than register (or field) width. | |||
2614 | void handleVectorShiftIntrinsic(IntrinsicInst &I, bool Variable) { | |||
2615 | assert(I.getNumArgOperands() == 2)((I.getNumArgOperands() == 2) ? static_cast<void> (0) : __assert_fail ("I.getNumArgOperands() == 2", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 2615, __PRETTY_FUNCTION__)); | |||
2616 | IRBuilder<> IRB(&I); | |||
2617 | // If any of the S2 bits are poisoned, the whole thing is poisoned. | |||
2618 | // Otherwise perform the same shift on S1. | |||
2619 | Value *S1 = getShadow(&I, 0); | |||
2620 | Value *S2 = getShadow(&I, 1); | |||
2621 | Value *S2Conv = Variable ? VariableShadowExtend(IRB, S2) | |||
2622 | : Lower64ShadowExtend(IRB, S2, getShadowTy(&I)); | |||
2623 | Value *V1 = I.getOperand(0); | |||
2624 | Value *V2 = I.getOperand(1); | |||
2625 | Value *Shift = IRB.CreateCall(I.getCalledValue(), | |||
2626 | {IRB.CreateBitCast(S1, V1->getType()), V2}); | |||
2627 | Shift = IRB.CreateBitCast(Shift, getShadowTy(&I)); | |||
2628 | setShadow(&I, IRB.CreateOr(Shift, S2Conv)); | |||
2629 | setOriginForNaryOp(I); | |||
2630 | } | |||
2631 | ||||
2632 | // Get an X86_MMX-sized vector type. | |||
2633 | Type *getMMXVectorTy(unsigned EltSizeInBits) { | |||
2634 | const unsigned X86_MMXSizeInBits = 64; | |||
2635 | return VectorType::get(IntegerType::get(*MS.C, EltSizeInBits), | |||
2636 | X86_MMXSizeInBits / EltSizeInBits); | |||
2637 | } | |||
2638 | ||||
2639 | // Returns a signed counterpart for an (un)signed-saturate-and-pack | |||
2640 | // intrinsic. | |||
2641 | Intrinsic::ID getSignedPackIntrinsic(Intrinsic::ID id) { | |||
2642 | switch (id) { | |||
2643 | case Intrinsic::x86_sse2_packsswb_128: | |||
2644 | case Intrinsic::x86_sse2_packuswb_128: | |||
2645 | return Intrinsic::x86_sse2_packsswb_128; | |||
2646 | ||||
2647 | case Intrinsic::x86_sse2_packssdw_128: | |||
2648 | case Intrinsic::x86_sse41_packusdw: | |||
2649 | return Intrinsic::x86_sse2_packssdw_128; | |||
2650 | ||||
2651 | case Intrinsic::x86_avx2_packsswb: | |||
2652 | case Intrinsic::x86_avx2_packuswb: | |||
2653 | return Intrinsic::x86_avx2_packsswb; | |||
2654 | ||||
2655 | case Intrinsic::x86_avx2_packssdw: | |||
2656 | case Intrinsic::x86_avx2_packusdw: | |||
2657 | return Intrinsic::x86_avx2_packssdw; | |||
2658 | ||||
2659 | case Intrinsic::x86_mmx_packsswb: | |||
2660 | case Intrinsic::x86_mmx_packuswb: | |||
2661 | return Intrinsic::x86_mmx_packsswb; | |||
2662 | ||||
2663 | case Intrinsic::x86_mmx_packssdw: | |||
2664 | return Intrinsic::x86_mmx_packssdw; | |||
2665 | default: | |||
2666 | llvm_unreachable("unexpected intrinsic id")::llvm::llvm_unreachable_internal("unexpected intrinsic id", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 2666); | |||
2667 | } | |||
2668 | } | |||
2669 | ||||
2670 | // Instrument vector pack instrinsic. | |||
2671 | // | |||
2672 | // This function instruments intrinsics like x86_mmx_packsswb, that | |||
2673 | // packs elements of 2 input vectors into half as many bits with saturation. | |||
2674 | // Shadow is propagated with the signed variant of the same intrinsic applied | |||
2675 | // to sext(Sa != zeroinitializer), sext(Sb != zeroinitializer). | |||
2676 | // EltSizeInBits is used only for x86mmx arguments. | |||
2677 | void handleVectorPackIntrinsic(IntrinsicInst &I, unsigned EltSizeInBits = 0) { | |||
2678 | assert(I.getNumArgOperands() == 2)((I.getNumArgOperands() == 2) ? static_cast<void> (0) : __assert_fail ("I.getNumArgOperands() == 2", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 2678, __PRETTY_FUNCTION__)); | |||
2679 | bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy(); | |||
2680 | IRBuilder<> IRB(&I); | |||
2681 | Value *S1 = getShadow(&I, 0); | |||
2682 | Value *S2 = getShadow(&I, 1); | |||
2683 | assert(isX86_MMX || S1->getType()->isVectorTy())((isX86_MMX || S1->getType()->isVectorTy()) ? static_cast <void> (0) : __assert_fail ("isX86_MMX || S1->getType()->isVectorTy()" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 2683, __PRETTY_FUNCTION__)); | |||
2684 | ||||
2685 | // SExt and ICmpNE below must apply to individual elements of input vectors. | |||
2686 | // In case of x86mmx arguments, cast them to appropriate vector types and | |||
2687 | // back. | |||
2688 | Type *T = isX86_MMX ? getMMXVectorTy(EltSizeInBits) : S1->getType(); | |||
2689 | if (isX86_MMX) { | |||
2690 | S1 = IRB.CreateBitCast(S1, T); | |||
2691 | S2 = IRB.CreateBitCast(S2, T); | |||
2692 | } | |||
2693 | Value *S1_ext = IRB.CreateSExt( | |||
2694 | IRB.CreateICmpNE(S1, Constant::getNullValue(T)), T); | |||
2695 | Value *S2_ext = IRB.CreateSExt( | |||
2696 | IRB.CreateICmpNE(S2, Constant::getNullValue(T)), T); | |||
2697 | if (isX86_MMX) { | |||
2698 | Type *X86_MMXTy = Type::getX86_MMXTy(*MS.C); | |||
2699 | S1_ext = IRB.CreateBitCast(S1_ext, X86_MMXTy); | |||
2700 | S2_ext = IRB.CreateBitCast(S2_ext, X86_MMXTy); | |||
2701 | } | |||
2702 | ||||
2703 | Function *ShadowFn = Intrinsic::getDeclaration( | |||
2704 | F.getParent(), getSignedPackIntrinsic(I.getIntrinsicID())); | |||
2705 | ||||
2706 | Value *S = | |||
2707 | IRB.CreateCall(ShadowFn, {S1_ext, S2_ext}, "_msprop_vector_pack"); | |||
2708 | if (isX86_MMX) S = IRB.CreateBitCast(S, getShadowTy(&I)); | |||
2709 | setShadow(&I, S); | |||
2710 | setOriginForNaryOp(I); | |||
2711 | } | |||
2712 | ||||
2713 | // Instrument sum-of-absolute-differencies intrinsic. | |||
2714 | void handleVectorSadIntrinsic(IntrinsicInst &I) { | |||
2715 | const unsigned SignificantBitsPerResultElement = 16; | |||
2716 | bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy(); | |||
2717 | Type *ResTy = isX86_MMX ? IntegerType::get(*MS.C, 64) : I.getType(); | |||
2718 | unsigned ZeroBitsPerResultElement = | |||
2719 | ResTy->getScalarSizeInBits() - SignificantBitsPerResultElement; | |||
2720 | ||||
2721 | IRBuilder<> IRB(&I); | |||
2722 | Value *S = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1)); | |||
2723 | S = IRB.CreateBitCast(S, ResTy); | |||
2724 | S = IRB.CreateSExt(IRB.CreateICmpNE(S, Constant::getNullValue(ResTy)), | |||
2725 | ResTy); | |||
2726 | S = IRB.CreateLShr(S, ZeroBitsPerResultElement); | |||
2727 | S = IRB.CreateBitCast(S, getShadowTy(&I)); | |||
2728 | setShadow(&I, S); | |||
2729 | setOriginForNaryOp(I); | |||
2730 | } | |||
2731 | ||||
2732 | // Instrument multiply-add intrinsic. | |||
2733 | void handleVectorPmaddIntrinsic(IntrinsicInst &I, | |||
2734 | unsigned EltSizeInBits = 0) { | |||
2735 | bool isX86_MMX = I.getOperand(0)->getType()->isX86_MMXTy(); | |||
2736 | Type *ResTy = isX86_MMX ? getMMXVectorTy(EltSizeInBits * 2) : I.getType(); | |||
2737 | IRBuilder<> IRB(&I); | |||
2738 | Value *S = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1)); | |||
2739 | S = IRB.CreateBitCast(S, ResTy); | |||
2740 | S = IRB.CreateSExt(IRB.CreateICmpNE(S, Constant::getNullValue(ResTy)), | |||
2741 | ResTy); | |||
2742 | S = IRB.CreateBitCast(S, getShadowTy(&I)); | |||
2743 | setShadow(&I, S); | |||
2744 | setOriginForNaryOp(I); | |||
2745 | } | |||
2746 | ||||
2747 | // Instrument compare-packed intrinsic. | |||
2748 | // Basically, an or followed by sext(icmp ne 0) to end up with all-zeros or | |||
2749 | // all-ones shadow. | |||
2750 | void handleVectorComparePackedIntrinsic(IntrinsicInst &I) { | |||
2751 | IRBuilder<> IRB(&I); | |||
2752 | Type *ResTy = getShadowTy(&I); | |||
2753 | Value *S0 = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1)); | |||
2754 | Value *S = IRB.CreateSExt( | |||
2755 | IRB.CreateICmpNE(S0, Constant::getNullValue(ResTy)), ResTy); | |||
2756 | setShadow(&I, S); | |||
2757 | setOriginForNaryOp(I); | |||
2758 | } | |||
2759 | ||||
2760 | // Instrument compare-scalar intrinsic. | |||
2761 | // This handles both cmp* intrinsics which return the result in the first | |||
2762 | // element of a vector, and comi* which return the result as i32. | |||
2763 | void handleVectorCompareScalarIntrinsic(IntrinsicInst &I) { | |||
2764 | IRBuilder<> IRB(&I); | |||
2765 | Value *S0 = IRB.CreateOr(getShadow(&I, 0), getShadow(&I, 1)); | |||
2766 | Value *S = LowerElementShadowExtend(IRB, S0, getShadowTy(&I)); | |||
2767 | setShadow(&I, S); | |||
2768 | setOriginForNaryOp(I); | |||
2769 | } | |||
2770 | ||||
2771 | void handleStmxcsr(IntrinsicInst &I) { | |||
2772 | IRBuilder<> IRB(&I); | |||
2773 | Value* Addr = I.getArgOperand(0); | |||
2774 | Type *Ty = IRB.getInt32Ty(); | |||
2775 | Value *ShadowPtr = | |||
2776 | getShadowOriginPtr(Addr, IRB, Ty, /*Alignment*/ 1, /*isStore*/ true) | |||
2777 | .first; | |||
2778 | ||||
2779 | IRB.CreateStore(getCleanShadow(Ty), | |||
2780 | IRB.CreatePointerCast(ShadowPtr, Ty->getPointerTo())); | |||
2781 | ||||
2782 | if (ClCheckAccessAddress) | |||
2783 | insertShadowCheck(Addr, &I); | |||
2784 | } | |||
2785 | ||||
2786 | void handleLdmxcsr(IntrinsicInst &I) { | |||
2787 | if (!InsertChecks) return; | |||
2788 | ||||
2789 | IRBuilder<> IRB(&I); | |||
2790 | Value *Addr = I.getArgOperand(0); | |||
2791 | Type *Ty = IRB.getInt32Ty(); | |||
2792 | unsigned Alignment = 1; | |||
2793 | Value *ShadowPtr, *OriginPtr; | |||
2794 | std::tie(ShadowPtr, OriginPtr) = | |||
2795 | getShadowOriginPtr(Addr, IRB, Ty, Alignment, /*isStore*/ false); | |||
2796 | ||||
2797 | if (ClCheckAccessAddress) | |||
2798 | insertShadowCheck(Addr, &I); | |||
2799 | ||||
2800 | Value *Shadow = IRB.CreateAlignedLoad(ShadowPtr, Alignment, "_ldmxcsr"); | |||
2801 | Value *Origin = | |||
2802 | MS.TrackOrigins ? IRB.CreateLoad(OriginPtr) : getCleanOrigin(); | |||
2803 | insertShadowCheck(Shadow, Origin, &I); | |||
2804 | } | |||
2805 | ||||
2806 | void handleMaskedStore(IntrinsicInst &I) { | |||
2807 | IRBuilder<> IRB(&I); | |||
2808 | Value *V = I.getArgOperand(0); | |||
2809 | Value *Addr = I.getArgOperand(1); | |||
2810 | unsigned Align = cast<ConstantInt>(I.getArgOperand(2))->getZExtValue(); | |||
2811 | Value *Mask = I.getArgOperand(3); | |||
2812 | Value *Shadow = getShadow(V); | |||
2813 | ||||
2814 | Value *ShadowPtr; | |||
2815 | Value *OriginPtr; | |||
2816 | std::tie(ShadowPtr, OriginPtr) = getShadowOriginPtr( | |||
2817 | Addr, IRB, Shadow->getType(), Align, /*isStore*/ true); | |||
2818 | ||||
2819 | if (ClCheckAccessAddress) { | |||
2820 | insertShadowCheck(Addr, &I); | |||
2821 | // Uninitialized mask is kind of like uninitialized address, but not as | |||
2822 | // scary. | |||
2823 | insertShadowCheck(Mask, &I); | |||
2824 | } | |||
2825 | ||||
2826 | IRB.CreateMaskedStore(Shadow, ShadowPtr, Align, Mask); | |||
2827 | ||||
2828 | if (MS.TrackOrigins) { | |||
2829 | auto &DL = F.getParent()->getDataLayout(); | |||
2830 | paintOrigin(IRB, getOrigin(V), OriginPtr, | |||
2831 | DL.getTypeStoreSize(Shadow->getType()), | |||
2832 | std::max(Align, kMinOriginAlignment)); | |||
2833 | } | |||
2834 | } | |||
2835 | ||||
2836 | bool handleMaskedLoad(IntrinsicInst &I) { | |||
2837 | IRBuilder<> IRB(&I); | |||
2838 | Value *Addr = I.getArgOperand(0); | |||
2839 | unsigned Align = cast<ConstantInt>(I.getArgOperand(1))->getZExtValue(); | |||
2840 | Value *Mask = I.getArgOperand(2); | |||
2841 | Value *PassThru = I.getArgOperand(3); | |||
2842 | ||||
2843 | Type *ShadowTy = getShadowTy(&I); | |||
2844 | Value *ShadowPtr, *OriginPtr; | |||
2845 | if (PropagateShadow) { | |||
2846 | std::tie(ShadowPtr, OriginPtr) = | |||
2847 | getShadowOriginPtr(Addr, IRB, ShadowTy, Align, /*isStore*/ false); | |||
2848 | setShadow(&I, IRB.CreateMaskedLoad(ShadowPtr, Align, Mask, | |||
2849 | getShadow(PassThru), "_msmaskedld")); | |||
2850 | } else { | |||
2851 | setShadow(&I, getCleanShadow(&I)); | |||
2852 | } | |||
2853 | ||||
2854 | if (ClCheckAccessAddress) { | |||
2855 | insertShadowCheck(Addr, &I); | |||
2856 | insertShadowCheck(Mask, &I); | |||
2857 | } | |||
2858 | ||||
2859 | if (MS.TrackOrigins) { | |||
2860 | if (PropagateShadow) { | |||
2861 | // Choose between PassThru's and the loaded value's origins. | |||
2862 | Value *MaskedPassThruShadow = IRB.CreateAnd( | |||
2863 | getShadow(PassThru), IRB.CreateSExt(IRB.CreateNeg(Mask), ShadowTy)); | |||
2864 | ||||
2865 | Value *Acc = IRB.CreateExtractElement( | |||
2866 | MaskedPassThruShadow, ConstantInt::get(IRB.getInt32Ty(), 0)); | |||
2867 | for (int i = 1, N = PassThru->getType()->getVectorNumElements(); i < N; | |||
2868 | ++i) { | |||
2869 | Value *More = IRB.CreateExtractElement( | |||
2870 | MaskedPassThruShadow, ConstantInt::get(IRB.getInt32Ty(), i)); | |||
2871 | Acc = IRB.CreateOr(Acc, More); | |||
2872 | } | |||
2873 | ||||
2874 | Value *Origin = IRB.CreateSelect( | |||
2875 | IRB.CreateICmpNE(Acc, Constant::getNullValue(Acc->getType())), | |||
2876 | getOrigin(PassThru), IRB.CreateLoad(OriginPtr)); | |||
2877 | ||||
2878 | setOrigin(&I, Origin); | |||
2879 | } else { | |||
2880 | setOrigin(&I, getCleanOrigin()); | |||
2881 | } | |||
2882 | } | |||
2883 | return true; | |||
2884 | } | |||
2885 | ||||
2886 | ||||
2887 | void visitIntrinsicInst(IntrinsicInst &I) { | |||
2888 | switch (I.getIntrinsicID()) { | |||
| ||||
2889 | case Intrinsic::bswap: | |||
2890 | handleBswap(I); | |||
2891 | break; | |||
2892 | case Intrinsic::masked_store: | |||
2893 | handleMaskedStore(I); | |||
2894 | break; | |||
2895 | case Intrinsic::masked_load: | |||
2896 | handleMaskedLoad(I); | |||
2897 | break; | |||
2898 | case Intrinsic::x86_sse_stmxcsr: | |||
2899 | handleStmxcsr(I); | |||
2900 | break; | |||
2901 | case Intrinsic::x86_sse_ldmxcsr: | |||
2902 | handleLdmxcsr(I); | |||
2903 | break; | |||
2904 | case Intrinsic::x86_avx512_vcvtsd2usi64: | |||
2905 | case Intrinsic::x86_avx512_vcvtsd2usi32: | |||
2906 | case Intrinsic::x86_avx512_vcvtss2usi64: | |||
2907 | case Intrinsic::x86_avx512_vcvtss2usi32: | |||
2908 | case Intrinsic::x86_avx512_cvttss2usi64: | |||
2909 | case Intrinsic::x86_avx512_cvttss2usi: | |||
2910 | case Intrinsic::x86_avx512_cvttsd2usi64: | |||
2911 | case Intrinsic::x86_avx512_cvttsd2usi: | |||
2912 | case Intrinsic::x86_avx512_cvtusi2ss: | |||
2913 | case Intrinsic::x86_avx512_cvtusi642sd: | |||
2914 | case Intrinsic::x86_avx512_cvtusi642ss: | |||
2915 | case Intrinsic::x86_sse2_cvtsd2si64: | |||
2916 | case Intrinsic::x86_sse2_cvtsd2si: | |||
2917 | case Intrinsic::x86_sse2_cvtsd2ss: | |||
2918 | case Intrinsic::x86_sse2_cvttsd2si64: | |||
2919 | case Intrinsic::x86_sse2_cvttsd2si: | |||
2920 | case Intrinsic::x86_sse_cvtss2si64: | |||
2921 | case Intrinsic::x86_sse_cvtss2si: | |||
2922 | case Intrinsic::x86_sse_cvttss2si64: | |||
2923 | case Intrinsic::x86_sse_cvttss2si: | |||
2924 | handleVectorConvertIntrinsic(I, 1); | |||
2925 | break; | |||
2926 | case Intrinsic::x86_sse_cvtps2pi: | |||
2927 | case Intrinsic::x86_sse_cvttps2pi: | |||
2928 | handleVectorConvertIntrinsic(I, 2); | |||
2929 | break; | |||
2930 | ||||
2931 | case Intrinsic::x86_avx512_psll_w_512: | |||
2932 | case Intrinsic::x86_avx512_psll_d_512: | |||
2933 | case Intrinsic::x86_avx512_psll_q_512: | |||
2934 | case Intrinsic::x86_avx512_pslli_w_512: | |||
2935 | case Intrinsic::x86_avx512_pslli_d_512: | |||
2936 | case Intrinsic::x86_avx512_pslli_q_512: | |||
2937 | case Intrinsic::x86_avx512_psrl_w_512: | |||
2938 | case Intrinsic::x86_avx512_psrl_d_512: | |||
2939 | case Intrinsic::x86_avx512_psrl_q_512: | |||
2940 | case Intrinsic::x86_avx512_psra_w_512: | |||
2941 | case Intrinsic::x86_avx512_psra_d_512: | |||
2942 | case Intrinsic::x86_avx512_psra_q_512: | |||
2943 | case Intrinsic::x86_avx512_psrli_w_512: | |||
2944 | case Intrinsic::x86_avx512_psrli_d_512: | |||
2945 | case Intrinsic::x86_avx512_psrli_q_512: | |||
2946 | case Intrinsic::x86_avx512_psrai_w_512: | |||
2947 | case Intrinsic::x86_avx512_psrai_d_512: | |||
2948 | case Intrinsic::x86_avx512_psrai_q_512: | |||
2949 | case Intrinsic::x86_avx512_psra_q_256: | |||
2950 | case Intrinsic::x86_avx512_psra_q_128: | |||
2951 | case Intrinsic::x86_avx512_psrai_q_256: | |||
2952 | case Intrinsic::x86_avx512_psrai_q_128: | |||
2953 | case Intrinsic::x86_avx2_psll_w: | |||
2954 | case Intrinsic::x86_avx2_psll_d: | |||
2955 | case Intrinsic::x86_avx2_psll_q: | |||
2956 | case Intrinsic::x86_avx2_pslli_w: | |||
2957 | case Intrinsic::x86_avx2_pslli_d: | |||
2958 | case Intrinsic::x86_avx2_pslli_q: | |||
2959 | case Intrinsic::x86_avx2_psrl_w: | |||
2960 | case Intrinsic::x86_avx2_psrl_d: | |||
2961 | case Intrinsic::x86_avx2_psrl_q: | |||
2962 | case Intrinsic::x86_avx2_psra_w: | |||
2963 | case Intrinsic::x86_avx2_psra_d: | |||
2964 | case Intrinsic::x86_avx2_psrli_w: | |||
2965 | case Intrinsic::x86_avx2_psrli_d: | |||
2966 | case Intrinsic::x86_avx2_psrli_q: | |||
2967 | case Intrinsic::x86_avx2_psrai_w: | |||
2968 | case Intrinsic::x86_avx2_psrai_d: | |||
2969 | case Intrinsic::x86_sse2_psll_w: | |||
2970 | case Intrinsic::x86_sse2_psll_d: | |||
2971 | case Intrinsic::x86_sse2_psll_q: | |||
2972 | case Intrinsic::x86_sse2_pslli_w: | |||
2973 | case Intrinsic::x86_sse2_pslli_d: | |||
2974 | case Intrinsic::x86_sse2_pslli_q: | |||
2975 | case Intrinsic::x86_sse2_psrl_w: | |||
2976 | case Intrinsic::x86_sse2_psrl_d: | |||
2977 | case Intrinsic::x86_sse2_psrl_q: | |||
2978 | case Intrinsic::x86_sse2_psra_w: | |||
2979 | case Intrinsic::x86_sse2_psra_d: | |||
2980 | case Intrinsic::x86_sse2_psrli_w: | |||
2981 | case Intrinsic::x86_sse2_psrli_d: | |||
2982 | case Intrinsic::x86_sse2_psrli_q: | |||
2983 | case Intrinsic::x86_sse2_psrai_w: | |||
2984 | case Intrinsic::x86_sse2_psrai_d: | |||
2985 | case Intrinsic::x86_mmx_psll_w: | |||
2986 | case Intrinsic::x86_mmx_psll_d: | |||
2987 | case Intrinsic::x86_mmx_psll_q: | |||
2988 | case Intrinsic::x86_mmx_pslli_w: | |||
2989 | case Intrinsic::x86_mmx_pslli_d: | |||
2990 | case Intrinsic::x86_mmx_pslli_q: | |||
2991 | case Intrinsic::x86_mmx_psrl_w: | |||
2992 | case Intrinsic::x86_mmx_psrl_d: | |||
2993 | case Intrinsic::x86_mmx_psrl_q: | |||
2994 | case Intrinsic::x86_mmx_psra_w: | |||
2995 | case Intrinsic::x86_mmx_psra_d: | |||
2996 | case Intrinsic::x86_mmx_psrli_w: | |||
2997 | case Intrinsic::x86_mmx_psrli_d: | |||
2998 | case Intrinsic::x86_mmx_psrli_q: | |||
2999 | case Intrinsic::x86_mmx_psrai_w: | |||
3000 | case Intrinsic::x86_mmx_psrai_d: | |||
3001 | handleVectorShiftIntrinsic(I, /* Variable */ false); | |||
3002 | break; | |||
3003 | case Intrinsic::x86_avx2_psllv_d: | |||
3004 | case Intrinsic::x86_avx2_psllv_d_256: | |||
3005 | case Intrinsic::x86_avx512_psllv_d_512: | |||
3006 | case Intrinsic::x86_avx2_psllv_q: | |||
3007 | case Intrinsic::x86_avx2_psllv_q_256: | |||
3008 | case Intrinsic::x86_avx512_psllv_q_512: | |||
3009 | case Intrinsic::x86_avx2_psrlv_d: | |||
3010 | case Intrinsic::x86_avx2_psrlv_d_256: | |||
3011 | case Intrinsic::x86_avx512_psrlv_d_512: | |||
3012 | case Intrinsic::x86_avx2_psrlv_q: | |||
3013 | case Intrinsic::x86_avx2_psrlv_q_256: | |||
3014 | case Intrinsic::x86_avx512_psrlv_q_512: | |||
3015 | case Intrinsic::x86_avx2_psrav_d: | |||
3016 | case Intrinsic::x86_avx2_psrav_d_256: | |||
3017 | case Intrinsic::x86_avx512_psrav_d_512: | |||
3018 | case Intrinsic::x86_avx512_psrav_q_128: | |||
3019 | case Intrinsic::x86_avx512_psrav_q_256: | |||
3020 | case Intrinsic::x86_avx512_psrav_q_512: | |||
3021 | handleVectorShiftIntrinsic(I, /* Variable */ true); | |||
3022 | break; | |||
3023 | ||||
3024 | case Intrinsic::x86_sse2_packsswb_128: | |||
3025 | case Intrinsic::x86_sse2_packssdw_128: | |||
3026 | case Intrinsic::x86_sse2_packuswb_128: | |||
3027 | case Intrinsic::x86_sse41_packusdw: | |||
3028 | case Intrinsic::x86_avx2_packsswb: | |||
3029 | case Intrinsic::x86_avx2_packssdw: | |||
3030 | case Intrinsic::x86_avx2_packuswb: | |||
3031 | case Intrinsic::x86_avx2_packusdw: | |||
3032 | handleVectorPackIntrinsic(I); | |||
3033 | break; | |||
3034 | ||||
3035 | case Intrinsic::x86_mmx_packsswb: | |||
3036 | case Intrinsic::x86_mmx_packuswb: | |||
3037 | handleVectorPackIntrinsic(I, 16); | |||
3038 | break; | |||
3039 | ||||
3040 | case Intrinsic::x86_mmx_packssdw: | |||
3041 | handleVectorPackIntrinsic(I, 32); | |||
3042 | break; | |||
3043 | ||||
3044 | case Intrinsic::x86_mmx_psad_bw: | |||
3045 | case Intrinsic::x86_sse2_psad_bw: | |||
3046 | case Intrinsic::x86_avx2_psad_bw: | |||
3047 | handleVectorSadIntrinsic(I); | |||
3048 | break; | |||
3049 | ||||
3050 | case Intrinsic::x86_sse2_pmadd_wd: | |||
3051 | case Intrinsic::x86_avx2_pmadd_wd: | |||
3052 | case Intrinsic::x86_ssse3_pmadd_ub_sw_128: | |||
3053 | case Intrinsic::x86_avx2_pmadd_ub_sw: | |||
3054 | handleVectorPmaddIntrinsic(I); | |||
3055 | break; | |||
3056 | ||||
3057 | case Intrinsic::x86_ssse3_pmadd_ub_sw: | |||
3058 | handleVectorPmaddIntrinsic(I, 8); | |||
3059 | break; | |||
3060 | ||||
3061 | case Intrinsic::x86_mmx_pmadd_wd: | |||
3062 | handleVectorPmaddIntrinsic(I, 16); | |||
3063 | break; | |||
3064 | ||||
3065 | case Intrinsic::x86_sse_cmp_ss: | |||
3066 | case Intrinsic::x86_sse2_cmp_sd: | |||
3067 | case Intrinsic::x86_sse_comieq_ss: | |||
3068 | case Intrinsic::x86_sse_comilt_ss: | |||
3069 | case Intrinsic::x86_sse_comile_ss: | |||
3070 | case Intrinsic::x86_sse_comigt_ss: | |||
3071 | case Intrinsic::x86_sse_comige_ss: | |||
3072 | case Intrinsic::x86_sse_comineq_ss: | |||
3073 | case Intrinsic::x86_sse_ucomieq_ss: | |||
3074 | case Intrinsic::x86_sse_ucomilt_ss: | |||
3075 | case Intrinsic::x86_sse_ucomile_ss: | |||
3076 | case Intrinsic::x86_sse_ucomigt_ss: | |||
3077 | case Intrinsic::x86_sse_ucomige_ss: | |||
3078 | case Intrinsic::x86_sse_ucomineq_ss: | |||
3079 | case Intrinsic::x86_sse2_comieq_sd: | |||
3080 | case Intrinsic::x86_sse2_comilt_sd: | |||
3081 | case Intrinsic::x86_sse2_comile_sd: | |||
3082 | case Intrinsic::x86_sse2_comigt_sd: | |||
3083 | case Intrinsic::x86_sse2_comige_sd: | |||
3084 | case Intrinsic::x86_sse2_comineq_sd: | |||
3085 | case Intrinsic::x86_sse2_ucomieq_sd: | |||
3086 | case Intrinsic::x86_sse2_ucomilt_sd: | |||
3087 | case Intrinsic::x86_sse2_ucomile_sd: | |||
3088 | case Intrinsic::x86_sse2_ucomigt_sd: | |||
3089 | case Intrinsic::x86_sse2_ucomige_sd: | |||
3090 | case Intrinsic::x86_sse2_ucomineq_sd: | |||
3091 | handleVectorCompareScalarIntrinsic(I); | |||
3092 | break; | |||
3093 | ||||
3094 | case Intrinsic::x86_sse_cmp_ps: | |||
3095 | case Intrinsic::x86_sse2_cmp_pd: | |||
3096 | // FIXME: For x86_avx_cmp_pd_256 and x86_avx_cmp_ps_256 this function | |||
3097 | // generates reasonably looking IR that fails in the backend with "Do not | |||
3098 | // know how to split the result of this operator!". | |||
3099 | handleVectorComparePackedIntrinsic(I); | |||
3100 | break; | |||
3101 | ||||
3102 | default: | |||
3103 | if (!handleUnknownIntrinsic(I)) | |||
3104 | visitInstruction(I); | |||
3105 | break; | |||
3106 | } | |||
3107 | } | |||
3108 | ||||
3109 | void visitCallSite(CallSite CS) { | |||
3110 | Instruction &I = *CS.getInstruction(); | |||
3111 | assert(!I.getMetadata("nosanitize"))((!I.getMetadata("nosanitize")) ? static_cast<void> (0) : __assert_fail ("!I.getMetadata(\"nosanitize\")", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3111, __PRETTY_FUNCTION__)); | |||
3112 | assert((CS.isCall() || CS.isInvoke()) && "Unknown type of CallSite")(((CS.isCall() || CS.isInvoke()) && "Unknown type of CallSite" ) ? static_cast<void> (0) : __assert_fail ("(CS.isCall() || CS.isInvoke()) && \"Unknown type of CallSite\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3112, __PRETTY_FUNCTION__)); | |||
3113 | if (CS.isCall()) { | |||
3114 | CallInst *Call = cast<CallInst>(&I); | |||
3115 | ||||
3116 | // For inline asm, do the usual thing: check argument shadow and mark all | |||
3117 | // outputs as clean. Note that any side effects of the inline asm that are | |||
3118 | // not immediately visible in its constraints are not handled. | |||
3119 | if (Call->isInlineAsm()) { | |||
3120 | if (ClHandleAsmConservative && MS.CompileKernel) | |||
3121 | visitAsmInstruction(I); | |||
3122 | else | |||
3123 | visitInstruction(I); | |||
3124 | return; | |||
3125 | } | |||
3126 | ||||
3127 | assert(!isa<IntrinsicInst>(&I) && "intrinsics are handled elsewhere")((!isa<IntrinsicInst>(&I) && "intrinsics are handled elsewhere" ) ? static_cast<void> (0) : __assert_fail ("!isa<IntrinsicInst>(&I) && \"intrinsics are handled elsewhere\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3127, __PRETTY_FUNCTION__)); | |||
3128 | ||||
3129 | // We are going to insert code that relies on the fact that the callee | |||
3130 | // will become a non-readonly function after it is instrumented by us. To | |||
3131 | // prevent this code from being optimized out, mark that function | |||
3132 | // non-readonly in advance. | |||
3133 | if (Function *Func = Call->getCalledFunction()) { | |||
3134 | // Clear out readonly/readnone attributes. | |||
3135 | AttrBuilder B; | |||
3136 | B.addAttribute(Attribute::ReadOnly) | |||
3137 | .addAttribute(Attribute::ReadNone); | |||
3138 | Func->removeAttributes(AttributeList::FunctionIndex, B); | |||
3139 | } | |||
3140 | ||||
3141 | maybeMarkSanitizerLibraryCallNoBuiltin(Call, TLI); | |||
3142 | } | |||
3143 | IRBuilder<> IRB(&I); | |||
3144 | ||||
3145 | unsigned ArgOffset = 0; | |||
3146 | LLVM_DEBUG(dbgs() << " CallSite: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " CallSite: " << I << "\n"; } } while (false); | |||
3147 | for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end(); | |||
3148 | ArgIt != End; ++ArgIt) { | |||
3149 | Value *A = *ArgIt; | |||
3150 | unsigned i = ArgIt - CS.arg_begin(); | |||
3151 | if (!A->getType()->isSized()) { | |||
3152 | LLVM_DEBUG(dbgs() << "Arg " << i << " is not sized: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << "Arg " << i << " is not sized: " << I << "\n"; } } while (false); | |||
3153 | continue; | |||
3154 | } | |||
3155 | unsigned Size = 0; | |||
3156 | Value *Store = nullptr; | |||
3157 | // Compute the Shadow for arg even if it is ByVal, because | |||
3158 | // in that case getShadow() will copy the actual arg shadow to | |||
3159 | // __msan_param_tls. | |||
3160 | Value *ArgShadow = getShadow(A); | |||
3161 | Value *ArgShadowBase = getShadowPtrForArgument(A, IRB, ArgOffset); | |||
3162 | LLVM_DEBUG(dbgs() << " Arg#" << i << ": " << *Ado { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " Arg#" << i << ": " << *A << " Shadow: " << *ArgShadow << "\n"; } } while (false) | |||
3163 | << " Shadow: " << *ArgShadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " Arg#" << i << ": " << *A << " Shadow: " << *ArgShadow << "\n"; } } while (false); | |||
3164 | bool ArgIsInitialized = false; | |||
3165 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
3166 | if (CS.paramHasAttr(i, Attribute::ByVal)) { | |||
3167 | assert(A->getType()->isPointerTy() &&((A->getType()->isPointerTy() && "ByVal argument is not a pointer!" ) ? static_cast<void> (0) : __assert_fail ("A->getType()->isPointerTy() && \"ByVal argument is not a pointer!\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3168, __PRETTY_FUNCTION__)) | |||
3168 | "ByVal argument is not a pointer!")((A->getType()->isPointerTy() && "ByVal argument is not a pointer!" ) ? static_cast<void> (0) : __assert_fail ("A->getType()->isPointerTy() && \"ByVal argument is not a pointer!\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3168, __PRETTY_FUNCTION__)); | |||
3169 | Size = DL.getTypeAllocSize(A->getType()->getPointerElementType()); | |||
3170 | if (ArgOffset + Size > kParamTLSSize) break; | |||
3171 | unsigned ParamAlignment = CS.getParamAlignment(i); | |||
3172 | unsigned Alignment = std::min(ParamAlignment, kShadowTLSAlignment); | |||
3173 | Value *AShadowPtr = | |||
3174 | getShadowOriginPtr(A, IRB, IRB.getInt8Ty(), Alignment, | |||
3175 | /*isStore*/ false) | |||
3176 | .first; | |||
3177 | ||||
3178 | Store = IRB.CreateMemCpy(ArgShadowBase, Alignment, AShadowPtr, | |||
3179 | Alignment, Size); | |||
3180 | // TODO(glider): need to copy origins. | |||
3181 | } else { | |||
3182 | Size = DL.getTypeAllocSize(A->getType()); | |||
3183 | if (ArgOffset + Size > kParamTLSSize) break; | |||
3184 | Store = IRB.CreateAlignedStore(ArgShadow, ArgShadowBase, | |||
3185 | kShadowTLSAlignment); | |||
3186 | Constant *Cst = dyn_cast<Constant>(ArgShadow); | |||
3187 | if (Cst && Cst->isNullValue()) ArgIsInitialized = true; | |||
3188 | } | |||
3189 | if (MS.TrackOrigins && !ArgIsInitialized) | |||
3190 | IRB.CreateStore(getOrigin(A), | |||
3191 | getOriginPtrForArgument(A, IRB, ArgOffset)); | |||
3192 | (void)Store; | |||
3193 | assert(Size != 0 && Store != nullptr)((Size != 0 && Store != nullptr) ? static_cast<void > (0) : __assert_fail ("Size != 0 && Store != nullptr" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3193, __PRETTY_FUNCTION__)); | |||
3194 | LLVM_DEBUG(dbgs() << " Param:" << *Store << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " Param:" << *Store << "\n"; } } while (false); | |||
3195 | ArgOffset += alignTo(Size, 8); | |||
3196 | } | |||
3197 | LLVM_DEBUG(dbgs() << " done with call args\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " done with call args\n"; } } while (false); | |||
3198 | ||||
3199 | FunctionType *FT = | |||
3200 | cast<FunctionType>(CS.getCalledValue()->getType()->getContainedType(0)); | |||
3201 | if (FT->isVarArg()) { | |||
3202 | VAHelper->visitCallSite(CS, IRB); | |||
3203 | } | |||
3204 | ||||
3205 | // Now, get the shadow for the RetVal. | |||
3206 | if (!I.getType()->isSized()) return; | |||
3207 | // Don't emit the epilogue for musttail call returns. | |||
3208 | if (CS.isCall() && cast<CallInst>(&I)->isMustTailCall()) return; | |||
3209 | IRBuilder<> IRBBefore(&I); | |||
3210 | // Until we have full dynamic coverage, make sure the retval shadow is 0. | |||
3211 | Value *Base = getShadowPtrForRetval(&I, IRBBefore); | |||
3212 | IRBBefore.CreateAlignedStore(getCleanShadow(&I), Base, kShadowTLSAlignment); | |||
3213 | BasicBlock::iterator NextInsn; | |||
3214 | if (CS.isCall()) { | |||
3215 | NextInsn = ++I.getIterator(); | |||
3216 | assert(NextInsn != I.getParent()->end())((NextInsn != I.getParent()->end()) ? static_cast<void> (0) : __assert_fail ("NextInsn != I.getParent()->end()", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3216, __PRETTY_FUNCTION__)); | |||
3217 | } else { | |||
3218 | BasicBlock *NormalDest = cast<InvokeInst>(&I)->getNormalDest(); | |||
3219 | if (!NormalDest->getSinglePredecessor()) { | |||
3220 | // FIXME: this case is tricky, so we are just conservative here. | |||
3221 | // Perhaps we need to split the edge between this BB and NormalDest, | |||
3222 | // but a naive attempt to use SplitEdge leads to a crash. | |||
3223 | setShadow(&I, getCleanShadow(&I)); | |||
3224 | setOrigin(&I, getCleanOrigin()); | |||
3225 | return; | |||
3226 | } | |||
3227 | // FIXME: NextInsn is likely in a basic block that has not been visited yet. | |||
3228 | // Anything inserted there will be instrumented by MSan later! | |||
3229 | NextInsn = NormalDest->getFirstInsertionPt(); | |||
3230 | assert(NextInsn != NormalDest->end() &&((NextInsn != NormalDest->end() && "Could not find insertion point for retval shadow load" ) ? static_cast<void> (0) : __assert_fail ("NextInsn != NormalDest->end() && \"Could not find insertion point for retval shadow load\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3231, __PRETTY_FUNCTION__)) | |||
3231 | "Could not find insertion point for retval shadow load")((NextInsn != NormalDest->end() && "Could not find insertion point for retval shadow load" ) ? static_cast<void> (0) : __assert_fail ("NextInsn != NormalDest->end() && \"Could not find insertion point for retval shadow load\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3231, __PRETTY_FUNCTION__)); | |||
3232 | } | |||
3233 | IRBuilder<> IRBAfter(&*NextInsn); | |||
3234 | Value *RetvalShadow = | |||
3235 | IRBAfter.CreateAlignedLoad(getShadowPtrForRetval(&I, IRBAfter), | |||
3236 | kShadowTLSAlignment, "_msret"); | |||
3237 | setShadow(&I, RetvalShadow); | |||
3238 | if (MS.TrackOrigins) | |||
3239 | setOrigin(&I, IRBAfter.CreateLoad(getOriginPtrForRetval(IRBAfter))); | |||
3240 | } | |||
3241 | ||||
3242 | bool isAMustTailRetVal(Value *RetVal) { | |||
3243 | if (auto *I = dyn_cast<BitCastInst>(RetVal)) { | |||
3244 | RetVal = I->getOperand(0); | |||
3245 | } | |||
3246 | if (auto *I = dyn_cast<CallInst>(RetVal)) { | |||
3247 | return I->isMustTailCall(); | |||
3248 | } | |||
3249 | return false; | |||
3250 | } | |||
3251 | ||||
3252 | void visitReturnInst(ReturnInst &I) { | |||
3253 | IRBuilder<> IRB(&I); | |||
3254 | Value *RetVal = I.getReturnValue(); | |||
3255 | if (!RetVal) return; | |||
3256 | // Don't emit the epilogue for musttail call returns. | |||
3257 | if (isAMustTailRetVal(RetVal)) return; | |||
3258 | Value *ShadowPtr = getShadowPtrForRetval(RetVal, IRB); | |||
3259 | if (CheckReturnValue) { | |||
3260 | insertShadowCheck(RetVal, &I); | |||
3261 | Value *Shadow = getCleanShadow(RetVal); | |||
3262 | IRB.CreateAlignedStore(Shadow, ShadowPtr, kShadowTLSAlignment); | |||
3263 | } else { | |||
3264 | Value *Shadow = getShadow(RetVal); | |||
3265 | IRB.CreateAlignedStore(Shadow, ShadowPtr, kShadowTLSAlignment); | |||
3266 | if (MS.TrackOrigins) | |||
3267 | IRB.CreateStore(getOrigin(RetVal), getOriginPtrForRetval(IRB)); | |||
3268 | } | |||
3269 | } | |||
3270 | ||||
3271 | void visitPHINode(PHINode &I) { | |||
3272 | IRBuilder<> IRB(&I); | |||
3273 | if (!PropagateShadow) { | |||
3274 | setShadow(&I, getCleanShadow(&I)); | |||
3275 | setOrigin(&I, getCleanOrigin()); | |||
3276 | return; | |||
3277 | } | |||
3278 | ||||
3279 | ShadowPHINodes.push_back(&I); | |||
3280 | setShadow(&I, IRB.CreatePHI(getShadowTy(&I), I.getNumIncomingValues(), | |||
3281 | "_msphi_s")); | |||
3282 | if (MS.TrackOrigins) | |||
3283 | setOrigin(&I, IRB.CreatePHI(MS.OriginTy, I.getNumIncomingValues(), | |||
3284 | "_msphi_o")); | |||
3285 | } | |||
3286 | ||||
3287 | Value *getLocalVarDescription(AllocaInst &I) { | |||
3288 | SmallString<2048> StackDescriptionStorage; | |||
3289 | raw_svector_ostream StackDescription(StackDescriptionStorage); | |||
3290 | // We create a string with a description of the stack allocation and | |||
3291 | // pass it into __msan_set_alloca_origin. | |||
3292 | // It will be printed by the run-time if stack-originated UMR is found. | |||
3293 | // The first 4 bytes of the string are set to '----' and will be replaced | |||
3294 | // by __msan_va_arg_overflow_size_tls at the first call. | |||
3295 | StackDescription << "----" << I.getName() << "@" << F.getName(); | |||
3296 | return createPrivateNonConstGlobalForString(*F.getParent(), | |||
3297 | StackDescription.str()); | |||
3298 | } | |||
3299 | ||||
3300 | void instrumentAllocaUserspace(AllocaInst &I, IRBuilder<> &IRB, Value *Len) { | |||
3301 | if (PoisonStack && ClPoisonStackWithCall) { | |||
3302 | IRB.CreateCall(MS.MsanPoisonStackFn, | |||
3303 | {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len}); | |||
3304 | } else { | |||
3305 | Value *ShadowBase, *OriginBase; | |||
3306 | std::tie(ShadowBase, OriginBase) = | |||
3307 | getShadowOriginPtr(&I, IRB, IRB.getInt8Ty(), 1, /*isStore*/ true); | |||
3308 | ||||
3309 | Value *PoisonValue = IRB.getInt8(PoisonStack ? ClPoisonStackPattern : 0); | |||
3310 | IRB.CreateMemSet(ShadowBase, PoisonValue, Len, I.getAlignment()); | |||
3311 | } | |||
3312 | ||||
3313 | if (PoisonStack && MS.TrackOrigins) { | |||
3314 | Value *Descr = getLocalVarDescription(I); | |||
3315 | IRB.CreateCall(MS.MsanSetAllocaOrigin4Fn, | |||
3316 | {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len, | |||
3317 | IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy()), | |||
3318 | IRB.CreatePointerCast(&F, MS.IntptrTy)}); | |||
3319 | } | |||
3320 | } | |||
3321 | ||||
3322 | void instrumentAllocaKmsan(AllocaInst &I, IRBuilder<> &IRB, Value *Len) { | |||
3323 | Value *Descr = getLocalVarDescription(I); | |||
3324 | if (PoisonStack) { | |||
3325 | IRB.CreateCall(MS.MsanPoisonAllocaFn, | |||
3326 | {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len, | |||
3327 | IRB.CreatePointerCast(Descr, IRB.getInt8PtrTy())}); | |||
3328 | } else { | |||
3329 | IRB.CreateCall(MS.MsanUnpoisonAllocaFn, | |||
3330 | {IRB.CreatePointerCast(&I, IRB.getInt8PtrTy()), Len}); | |||
3331 | } | |||
3332 | } | |||
3333 | ||||
3334 | void visitAllocaInst(AllocaInst &I) { | |||
3335 | setShadow(&I, getCleanShadow(&I)); | |||
3336 | setOrigin(&I, getCleanOrigin()); | |||
3337 | IRBuilder<> IRB(I.getNextNode()); | |||
3338 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
3339 | uint64_t TypeSize = DL.getTypeAllocSize(I.getAllocatedType()); | |||
3340 | Value *Len = ConstantInt::get(MS.IntptrTy, TypeSize); | |||
3341 | if (I.isArrayAllocation()) | |||
3342 | Len = IRB.CreateMul(Len, I.getArraySize()); | |||
3343 | ||||
3344 | if (MS.CompileKernel) | |||
3345 | instrumentAllocaKmsan(I, IRB, Len); | |||
3346 | else | |||
3347 | instrumentAllocaUserspace(I, IRB, Len); | |||
3348 | } | |||
3349 | ||||
3350 | void visitSelectInst(SelectInst& I) { | |||
3351 | IRBuilder<> IRB(&I); | |||
3352 | // a = select b, c, d | |||
3353 | Value *B = I.getCondition(); | |||
3354 | Value *C = I.getTrueValue(); | |||
3355 | Value *D = I.getFalseValue(); | |||
3356 | Value *Sb = getShadow(B); | |||
3357 | Value *Sc = getShadow(C); | |||
3358 | Value *Sd = getShadow(D); | |||
3359 | ||||
3360 | // Result shadow if condition shadow is 0. | |||
3361 | Value *Sa0 = IRB.CreateSelect(B, Sc, Sd); | |||
3362 | Value *Sa1; | |||
3363 | if (I.getType()->isAggregateType()) { | |||
3364 | // To avoid "sign extending" i1 to an arbitrary aggregate type, we just do | |||
3365 | // an extra "select". This results in much more compact IR. | |||
3366 | // Sa = select Sb, poisoned, (select b, Sc, Sd) | |||
3367 | Sa1 = getPoisonedShadow(getShadowTy(I.getType())); | |||
3368 | } else { | |||
3369 | // Sa = select Sb, [ (c^d) | Sc | Sd ], [ b ? Sc : Sd ] | |||
3370 | // If Sb (condition is poisoned), look for bits in c and d that are equal | |||
3371 | // and both unpoisoned. | |||
3372 | // If !Sb (condition is unpoisoned), simply pick one of Sc and Sd. | |||
3373 | ||||
3374 | // Cast arguments to shadow-compatible type. | |||
3375 | C = CreateAppToShadowCast(IRB, C); | |||
3376 | D = CreateAppToShadowCast(IRB, D); | |||
3377 | ||||
3378 | // Result shadow if condition shadow is 1. | |||
3379 | Sa1 = IRB.CreateOr(IRB.CreateXor(C, D), IRB.CreateOr(Sc, Sd)); | |||
3380 | } | |||
3381 | Value *Sa = IRB.CreateSelect(Sb, Sa1, Sa0, "_msprop_select"); | |||
3382 | setShadow(&I, Sa); | |||
3383 | if (MS.TrackOrigins) { | |||
3384 | // Origins are always i32, so any vector conditions must be flattened. | |||
3385 | // FIXME: consider tracking vector origins for app vectors? | |||
3386 | if (B->getType()->isVectorTy()) { | |||
3387 | Type *FlatTy = getShadowTyNoVec(B->getType()); | |||
3388 | B = IRB.CreateICmpNE(IRB.CreateBitCast(B, FlatTy), | |||
3389 | ConstantInt::getNullValue(FlatTy)); | |||
3390 | Sb = IRB.CreateICmpNE(IRB.CreateBitCast(Sb, FlatTy), | |||
3391 | ConstantInt::getNullValue(FlatTy)); | |||
3392 | } | |||
3393 | // a = select b, c, d | |||
3394 | // Oa = Sb ? Ob : (b ? Oc : Od) | |||
3395 | setOrigin( | |||
3396 | &I, IRB.CreateSelect(Sb, getOrigin(I.getCondition()), | |||
3397 | IRB.CreateSelect(B, getOrigin(I.getTrueValue()), | |||
3398 | getOrigin(I.getFalseValue())))); | |||
3399 | } | |||
3400 | } | |||
3401 | ||||
3402 | void visitLandingPadInst(LandingPadInst &I) { | |||
3403 | // Do nothing. | |||
3404 | // See https://github.com/google/sanitizers/issues/504 | |||
3405 | setShadow(&I, getCleanShadow(&I)); | |||
3406 | setOrigin(&I, getCleanOrigin()); | |||
3407 | } | |||
3408 | ||||
3409 | void visitCatchSwitchInst(CatchSwitchInst &I) { | |||
3410 | setShadow(&I, getCleanShadow(&I)); | |||
3411 | setOrigin(&I, getCleanOrigin()); | |||
3412 | } | |||
3413 | ||||
3414 | void visitFuncletPadInst(FuncletPadInst &I) { | |||
3415 | setShadow(&I, getCleanShadow(&I)); | |||
3416 | setOrigin(&I, getCleanOrigin()); | |||
3417 | } | |||
3418 | ||||
3419 | void visitGetElementPtrInst(GetElementPtrInst &I) { | |||
3420 | handleShadowOr(I); | |||
3421 | } | |||
3422 | ||||
3423 | void visitExtractValueInst(ExtractValueInst &I) { | |||
3424 | IRBuilder<> IRB(&I); | |||
3425 | Value *Agg = I.getAggregateOperand(); | |||
3426 | LLVM_DEBUG(dbgs() << "ExtractValue: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << "ExtractValue: " << I << "\n"; } } while (false); | |||
3427 | Value *AggShadow = getShadow(Agg); | |||
3428 | LLVM_DEBUG(dbgs() << " AggShadow: " << *AggShadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " AggShadow: " << *AggShadow << "\n"; } } while (false); | |||
3429 | Value *ResShadow = IRB.CreateExtractValue(AggShadow, I.getIndices()); | |||
3430 | LLVM_DEBUG(dbgs() << " ResShadow: " << *ResShadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " ResShadow: " << *ResShadow << "\n"; } } while (false); | |||
3431 | setShadow(&I, ResShadow); | |||
3432 | setOriginForNaryOp(I); | |||
3433 | } | |||
3434 | ||||
3435 | void visitInsertValueInst(InsertValueInst &I) { | |||
3436 | IRBuilder<> IRB(&I); | |||
3437 | LLVM_DEBUG(dbgs() << "InsertValue: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << "InsertValue: " << I << "\n"; } } while (false); | |||
3438 | Value *AggShadow = getShadow(I.getAggregateOperand()); | |||
3439 | Value *InsShadow = getShadow(I.getInsertedValueOperand()); | |||
3440 | LLVM_DEBUG(dbgs() << " AggShadow: " << *AggShadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " AggShadow: " << *AggShadow << "\n"; } } while (false); | |||
3441 | LLVM_DEBUG(dbgs() << " InsShadow: " << *InsShadow << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " InsShadow: " << *InsShadow << "\n"; } } while (false); | |||
3442 | Value *Res = IRB.CreateInsertValue(AggShadow, InsShadow, I.getIndices()); | |||
3443 | LLVM_DEBUG(dbgs() << " Res: " << *Res << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << " Res: " << *Res << "\n"; } } while (false); | |||
3444 | setShadow(&I, Res); | |||
3445 | setOriginForNaryOp(I); | |||
3446 | } | |||
3447 | ||||
3448 | void dumpInst(Instruction &I) { | |||
3449 | if (CallInst *CI = dyn_cast<CallInst>(&I)) { | |||
3450 | errs() << "ZZZ call " << CI->getCalledFunction()->getName() << "\n"; | |||
3451 | } else { | |||
3452 | errs() << "ZZZ " << I.getOpcodeName() << "\n"; | |||
3453 | } | |||
3454 | errs() << "QQQ " << I << "\n"; | |||
3455 | } | |||
3456 | ||||
3457 | void visitResumeInst(ResumeInst &I) { | |||
3458 | LLVM_DEBUG(dbgs() << "Resume: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << "Resume: " << I << "\n" ; } } while (false); | |||
3459 | // Nothing to do here. | |||
3460 | } | |||
3461 | ||||
3462 | void visitCleanupReturnInst(CleanupReturnInst &CRI) { | |||
3463 | LLVM_DEBUG(dbgs() << "CleanupReturn: " << CRI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << "CleanupReturn: " << CRI << "\n"; } } while (false); | |||
3464 | // Nothing to do here. | |||
3465 | } | |||
3466 | ||||
3467 | void visitCatchReturnInst(CatchReturnInst &CRI) { | |||
3468 | LLVM_DEBUG(dbgs() << "CatchReturn: " << CRI << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << "CatchReturn: " << CRI << "\n"; } } while (false); | |||
3469 | // Nothing to do here. | |||
3470 | } | |||
3471 | ||||
3472 | void instrumentAsmArgument(Value *Operand, Instruction &I, IRBuilder<> &IRB, | |||
3473 | const DataLayout &DL, bool isOutput) { | |||
3474 | // For each assembly argument, we check its value for being initialized. | |||
3475 | // If the argument is a pointer, we assume it points to a single element | |||
3476 | // of the corresponding type (or to a 8-byte word, if the type is unsized). | |||
3477 | // Each such pointer is instrumented with a call to the runtime library. | |||
3478 | Type *OpType = Operand->getType(); | |||
3479 | // Check the operand value itself. | |||
3480 | insertShadowCheck(Operand, &I); | |||
3481 | if (!OpType->isPointerTy() || !isOutput) { | |||
3482 | assert(!isOutput)((!isOutput) ? static_cast<void> (0) : __assert_fail ("!isOutput" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3482, __PRETTY_FUNCTION__)); | |||
3483 | return; | |||
3484 | } | |||
3485 | Type *ElType = OpType->getPointerElementType(); | |||
3486 | if (!ElType->isSized()) | |||
3487 | return; | |||
3488 | int Size = DL.getTypeStoreSize(ElType); | |||
3489 | Value *Ptr = IRB.CreatePointerCast(Operand, IRB.getInt8PtrTy()); | |||
3490 | Value *SizeVal = ConstantInt::get(MS.IntptrTy, Size); | |||
3491 | IRB.CreateCall(MS.MsanInstrumentAsmStoreFn, {Ptr, SizeVal}); | |||
3492 | } | |||
3493 | ||||
3494 | /// Get the number of output arguments returned by pointers. | |||
3495 | int getNumOutputArgs(InlineAsm *IA, CallInst *CI) { | |||
3496 | int NumRetOutputs = 0; | |||
3497 | int NumOutputs = 0; | |||
3498 | Type *RetTy = dyn_cast<Value>(CI)->getType(); | |||
3499 | if (!RetTy->isVoidTy()) { | |||
3500 | // Register outputs are returned via the CallInst return value. | |||
3501 | StructType *ST = dyn_cast_or_null<StructType>(RetTy); | |||
3502 | if (ST) | |||
3503 | NumRetOutputs = ST->getNumElements(); | |||
3504 | else | |||
3505 | NumRetOutputs = 1; | |||
3506 | } | |||
3507 | InlineAsm::ConstraintInfoVector Constraints = IA->ParseConstraints(); | |||
3508 | for (size_t i = 0, n = Constraints.size(); i < n; i++) { | |||
3509 | InlineAsm::ConstraintInfo Info = Constraints[i]; | |||
3510 | switch (Info.Type) { | |||
3511 | case InlineAsm::isOutput: | |||
3512 | NumOutputs++; | |||
3513 | break; | |||
3514 | default: | |||
3515 | break; | |||
3516 | } | |||
3517 | } | |||
3518 | return NumOutputs - NumRetOutputs; | |||
3519 | } | |||
3520 | ||||
3521 | void visitAsmInstruction(Instruction &I) { | |||
3522 | // Conservative inline assembly handling: check for poisoned shadow of | |||
3523 | // asm() arguments, then unpoison the result and all the memory locations | |||
3524 | // pointed to by those arguments. | |||
3525 | // An inline asm() statement in C++ contains lists of input and output | |||
3526 | // arguments used by the assembly code. These are mapped to operands of the | |||
3527 | // CallInst as follows: | |||
3528 | // - nR register outputs ("=r) are returned by value in a single structure | |||
3529 | // (SSA value of the CallInst); | |||
3530 | // - nO other outputs ("=m" and others) are returned by pointer as first | |||
3531 | // nO operands of the CallInst; | |||
3532 | // - nI inputs ("r", "m" and others) are passed to CallInst as the | |||
3533 | // remaining nI operands. | |||
3534 | // The total number of asm() arguments in the source is nR+nO+nI, and the | |||
3535 | // corresponding CallInst has nO+nI+1 operands (the last operand is the | |||
3536 | // function to be called). | |||
3537 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
3538 | CallInst *CI = dyn_cast<CallInst>(&I); | |||
3539 | IRBuilder<> IRB(&I); | |||
3540 | InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue()); | |||
3541 | int OutputArgs = getNumOutputArgs(IA, CI); | |||
3542 | // The last operand of a CallInst is the function itself. | |||
3543 | int NumOperands = CI->getNumOperands() - 1; | |||
3544 | ||||
3545 | // Check input arguments. Doing so before unpoisoning output arguments, so | |||
3546 | // that we won't overwrite uninit values before checking them. | |||
3547 | for (int i = OutputArgs; i < NumOperands; i++) { | |||
3548 | Value *Operand = CI->getOperand(i); | |||
3549 | instrumentAsmArgument(Operand, I, IRB, DL, /*isOutput*/ false); | |||
3550 | } | |||
3551 | // Unpoison output arguments. This must happen before the actual InlineAsm | |||
3552 | // call, so that the shadow for memory published in the asm() statement | |||
3553 | // remains valid. | |||
3554 | for (int i = 0; i < OutputArgs; i++) { | |||
3555 | Value *Operand = CI->getOperand(i); | |||
3556 | instrumentAsmArgument(Operand, I, IRB, DL, /*isOutput*/ true); | |||
3557 | } | |||
3558 | ||||
3559 | setShadow(&I, getCleanShadow(&I)); | |||
3560 | setOrigin(&I, getCleanOrigin()); | |||
3561 | } | |||
3562 | ||||
3563 | void visitInstruction(Instruction &I) { | |||
3564 | // Everything else: stop propagating and check for poisoned shadow. | |||
3565 | if (ClDumpStrictInstructions) | |||
3566 | dumpInst(I); | |||
3567 | LLVM_DEBUG(dbgs() << "DEFAULT: " << I << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("msan")) { dbgs() << "DEFAULT: " << I << "\n" ; } } while (false); | |||
3568 | for (size_t i = 0, n = I.getNumOperands(); i < n; i++) { | |||
3569 | Value *Operand = I.getOperand(i); | |||
3570 | if (Operand->getType()->isSized()) | |||
3571 | insertShadowCheck(Operand, &I); | |||
3572 | } | |||
3573 | setShadow(&I, getCleanShadow(&I)); | |||
3574 | setOrigin(&I, getCleanOrigin()); | |||
3575 | } | |||
3576 | }; | |||
3577 | ||||
3578 | /// AMD64-specific implementation of VarArgHelper. | |||
3579 | struct VarArgAMD64Helper : public VarArgHelper { | |||
3580 | // An unfortunate workaround for asymmetric lowering of va_arg stuff. | |||
3581 | // See a comment in visitCallSite for more details. | |||
3582 | static const unsigned AMD64GpEndOffset = 48; // AMD64 ABI Draft 0.99.6 p3.5.7 | |||
3583 | static const unsigned AMD64FpEndOffsetSSE = 176; | |||
3584 | // If SSE is disabled, fp_offset in va_list is zero. | |||
3585 | static const unsigned AMD64FpEndOffsetNoSSE = AMD64GpEndOffset; | |||
3586 | ||||
3587 | unsigned AMD64FpEndOffset; | |||
3588 | Function &F; | |||
3589 | MemorySanitizer &MS; | |||
3590 | MemorySanitizerVisitor &MSV; | |||
3591 | Value *VAArgTLSCopy = nullptr; | |||
3592 | Value *VAArgTLSOriginCopy = nullptr; | |||
3593 | Value *VAArgOverflowSize = nullptr; | |||
3594 | ||||
3595 | SmallVector<CallInst*, 16> VAStartInstrumentationList; | |||
3596 | ||||
3597 | enum ArgKind { AK_GeneralPurpose, AK_FloatingPoint, AK_Memory }; | |||
3598 | ||||
3599 | VarArgAMD64Helper(Function &F, MemorySanitizer &MS, | |||
3600 | MemorySanitizerVisitor &MSV) | |||
3601 | : F(F), MS(MS), MSV(MSV) { | |||
3602 | AMD64FpEndOffset = AMD64FpEndOffsetSSE; | |||
3603 | for (const auto &Attr : F.getAttributes().getFnAttributes()) { | |||
3604 | if (Attr.isStringAttribute() && | |||
3605 | (Attr.getKindAsString() == "target-features")) { | |||
3606 | if (Attr.getValueAsString().contains("-sse")) | |||
3607 | AMD64FpEndOffset = AMD64FpEndOffsetNoSSE; | |||
3608 | break; | |||
3609 | } | |||
3610 | } | |||
3611 | } | |||
3612 | ||||
3613 | ArgKind classifyArgument(Value* arg) { | |||
3614 | // A very rough approximation of X86_64 argument classification rules. | |||
3615 | Type *T = arg->getType(); | |||
3616 | if (T->isFPOrFPVectorTy() || T->isX86_MMXTy()) | |||
3617 | return AK_FloatingPoint; | |||
3618 | if (T->isIntegerTy() && T->getPrimitiveSizeInBits() <= 64) | |||
3619 | return AK_GeneralPurpose; | |||
3620 | if (T->isPointerTy()) | |||
3621 | return AK_GeneralPurpose; | |||
3622 | return AK_Memory; | |||
3623 | } | |||
3624 | ||||
3625 | // For VarArg functions, store the argument shadow in an ABI-specific format | |||
3626 | // that corresponds to va_list layout. | |||
3627 | // We do this because Clang lowers va_arg in the frontend, and this pass | |||
3628 | // only sees the low level code that deals with va_list internals. | |||
3629 | // A much easier alternative (provided that Clang emits va_arg instructions) | |||
3630 | // would have been to associate each live instance of va_list with a copy of | |||
3631 | // MSanParamTLS, and extract shadow on va_arg() call in the argument list | |||
3632 | // order. | |||
3633 | void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override { | |||
3634 | unsigned GpOffset = 0; | |||
3635 | unsigned FpOffset = AMD64GpEndOffset; | |||
3636 | unsigned OverflowOffset = AMD64FpEndOffset; | |||
3637 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
3638 | for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end(); | |||
3639 | ArgIt != End; ++ArgIt) { | |||
3640 | Value *A = *ArgIt; | |||
3641 | unsigned ArgNo = CS.getArgumentNo(ArgIt); | |||
3642 | bool IsFixed = ArgNo < CS.getFunctionType()->getNumParams(); | |||
3643 | bool IsByVal = CS.paramHasAttr(ArgNo, Attribute::ByVal); | |||
3644 | if (IsByVal) { | |||
3645 | // ByVal arguments always go to the overflow area. | |||
3646 | // Fixed arguments passed through the overflow area will be stepped | |||
3647 | // over by va_start, so don't count them towards the offset. | |||
3648 | if (IsFixed) | |||
3649 | continue; | |||
3650 | assert(A->getType()->isPointerTy())((A->getType()->isPointerTy()) ? static_cast<void> (0) : __assert_fail ("A->getType()->isPointerTy()", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3650, __PRETTY_FUNCTION__)); | |||
3651 | Type *RealTy = A->getType()->getPointerElementType(); | |||
3652 | uint64_t ArgSize = DL.getTypeAllocSize(RealTy); | |||
3653 | Value *ShadowBase = getShadowPtrForVAArgument( | |||
3654 | RealTy, IRB, OverflowOffset, alignTo(ArgSize, 8)); | |||
3655 | Value *OriginBase = nullptr; | |||
3656 | if (MS.TrackOrigins) | |||
3657 | OriginBase = getOriginPtrForVAArgument(RealTy, IRB, OverflowOffset); | |||
3658 | OverflowOffset += alignTo(ArgSize, 8); | |||
3659 | if (!ShadowBase) | |||
3660 | continue; | |||
3661 | Value *ShadowPtr, *OriginPtr; | |||
3662 | std::tie(ShadowPtr, OriginPtr) = | |||
3663 | MSV.getShadowOriginPtr(A, IRB, IRB.getInt8Ty(), kShadowTLSAlignment, | |||
3664 | /*isStore*/ false); | |||
3665 | ||||
3666 | IRB.CreateMemCpy(ShadowBase, kShadowTLSAlignment, ShadowPtr, | |||
3667 | kShadowTLSAlignment, ArgSize); | |||
3668 | if (MS.TrackOrigins) | |||
3669 | IRB.CreateMemCpy(OriginBase, kShadowTLSAlignment, OriginPtr, | |||
3670 | kShadowTLSAlignment, ArgSize); | |||
3671 | } else { | |||
3672 | ArgKind AK = classifyArgument(A); | |||
3673 | if (AK == AK_GeneralPurpose && GpOffset >= AMD64GpEndOffset) | |||
3674 | AK = AK_Memory; | |||
3675 | if (AK == AK_FloatingPoint && FpOffset >= AMD64FpEndOffset) | |||
3676 | AK = AK_Memory; | |||
3677 | Value *ShadowBase, *OriginBase = nullptr; | |||
3678 | switch (AK) { | |||
3679 | case AK_GeneralPurpose: | |||
3680 | ShadowBase = | |||
3681 | getShadowPtrForVAArgument(A->getType(), IRB, GpOffset, 8); | |||
3682 | if (MS.TrackOrigins) | |||
3683 | OriginBase = | |||
3684 | getOriginPtrForVAArgument(A->getType(), IRB, GpOffset); | |||
3685 | GpOffset += 8; | |||
3686 | break; | |||
3687 | case AK_FloatingPoint: | |||
3688 | ShadowBase = | |||
3689 | getShadowPtrForVAArgument(A->getType(), IRB, FpOffset, 16); | |||
3690 | if (MS.TrackOrigins) | |||
3691 | OriginBase = | |||
3692 | getOriginPtrForVAArgument(A->getType(), IRB, FpOffset); | |||
3693 | FpOffset += 16; | |||
3694 | break; | |||
3695 | case AK_Memory: | |||
3696 | if (IsFixed) | |||
3697 | continue; | |||
3698 | uint64_t ArgSize = DL.getTypeAllocSize(A->getType()); | |||
3699 | ShadowBase = | |||
3700 | getShadowPtrForVAArgument(A->getType(), IRB, OverflowOffset, 8); | |||
3701 | if (MS.TrackOrigins) | |||
3702 | OriginBase = | |||
3703 | getOriginPtrForVAArgument(A->getType(), IRB, OverflowOffset); | |||
3704 | OverflowOffset += alignTo(ArgSize, 8); | |||
3705 | } | |||
3706 | // Take fixed arguments into account for GpOffset and FpOffset, | |||
3707 | // but don't actually store shadows for them. | |||
3708 | // TODO(glider): don't call get*PtrForVAArgument() for them. | |||
3709 | if (IsFixed) | |||
3710 | continue; | |||
3711 | if (!ShadowBase) | |||
3712 | continue; | |||
3713 | Value *Shadow = MSV.getShadow(A); | |||
3714 | IRB.CreateAlignedStore(Shadow, ShadowBase, kShadowTLSAlignment); | |||
3715 | if (MS.TrackOrigins) { | |||
3716 | Value *Origin = MSV.getOrigin(A); | |||
3717 | unsigned StoreSize = DL.getTypeStoreSize(Shadow->getType()); | |||
3718 | MSV.paintOrigin(IRB, Origin, OriginBase, StoreSize, | |||
3719 | std::max(kShadowTLSAlignment, kMinOriginAlignment)); | |||
3720 | } | |||
3721 | } | |||
3722 | } | |||
3723 | Constant *OverflowSize = | |||
3724 | ConstantInt::get(IRB.getInt64Ty(), OverflowOffset - AMD64FpEndOffset); | |||
3725 | IRB.CreateStore(OverflowSize, MS.VAArgOverflowSizeTLS); | |||
3726 | } | |||
3727 | ||||
3728 | /// Compute the shadow address for a given va_arg. | |||
3729 | Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB, | |||
3730 | unsigned ArgOffset, unsigned ArgSize) { | |||
3731 | // Make sure we don't overflow __msan_va_arg_tls. | |||
3732 | if (ArgOffset + ArgSize > kParamTLSSize) | |||
3733 | return nullptr; | |||
3734 | Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy); | |||
3735 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
3736 | return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0), | |||
3737 | "_msarg_va_s"); | |||
3738 | } | |||
3739 | ||||
3740 | /// Compute the origin address for a given va_arg. | |||
3741 | Value *getOriginPtrForVAArgument(Type *Ty, IRBuilder<> &IRB, int ArgOffset) { | |||
3742 | Value *Base = IRB.CreatePointerCast(MS.VAArgOriginTLS, MS.IntptrTy); | |||
3743 | // getOriginPtrForVAArgument() is always called after | |||
3744 | // getShadowPtrForVAArgument(), so __msan_va_arg_origin_tls can never | |||
3745 | // overflow. | |||
3746 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
3747 | return IRB.CreateIntToPtr(Base, PointerType::get(MS.OriginTy, 0), | |||
3748 | "_msarg_va_o"); | |||
3749 | } | |||
3750 | ||||
3751 | void unpoisonVAListTagForInst(IntrinsicInst &I) { | |||
3752 | IRBuilder<> IRB(&I); | |||
3753 | Value *VAListTag = I.getArgOperand(0); | |||
3754 | Value *ShadowPtr, *OriginPtr; | |||
3755 | unsigned Alignment = 8; | |||
3756 | std::tie(ShadowPtr, OriginPtr) = | |||
3757 | MSV.getShadowOriginPtr(VAListTag, IRB, IRB.getInt8Ty(), Alignment, | |||
3758 | /*isStore*/ true); | |||
3759 | ||||
3760 | // Unpoison the whole __va_list_tag. | |||
3761 | // FIXME: magic ABI constants. | |||
3762 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
3763 | /* size */ 24, Alignment, false); | |||
3764 | // We shouldn't need to zero out the origins, as they're only checked for | |||
3765 | // nonzero shadow. | |||
3766 | } | |||
3767 | ||||
3768 | void visitVAStartInst(VAStartInst &I) override { | |||
3769 | if (F.getCallingConv() == CallingConv::Win64) | |||
3770 | return; | |||
3771 | VAStartInstrumentationList.push_back(&I); | |||
3772 | unpoisonVAListTagForInst(I); | |||
3773 | } | |||
3774 | ||||
3775 | void visitVACopyInst(VACopyInst &I) override { | |||
3776 | if (F.getCallingConv() == CallingConv::Win64) return; | |||
3777 | unpoisonVAListTagForInst(I); | |||
3778 | } | |||
3779 | ||||
3780 | void finalizeInstrumentation() override { | |||
3781 | assert(!VAArgOverflowSize && !VAArgTLSCopy &&((!VAArgOverflowSize && !VAArgTLSCopy && "finalizeInstrumentation called twice" ) ? static_cast<void> (0) : __assert_fail ("!VAArgOverflowSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3782, __PRETTY_FUNCTION__)) | |||
3782 | "finalizeInstrumentation called twice")((!VAArgOverflowSize && !VAArgTLSCopy && "finalizeInstrumentation called twice" ) ? static_cast<void> (0) : __assert_fail ("!VAArgOverflowSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3782, __PRETTY_FUNCTION__)); | |||
3783 | if (!VAStartInstrumentationList.empty()) { | |||
3784 | // If there is a va_start in this function, make a backup copy of | |||
3785 | // va_arg_tls somewhere in the function entry block. | |||
3786 | IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI()); | |||
3787 | VAArgOverflowSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS); | |||
3788 | Value *CopySize = | |||
3789 | IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, AMD64FpEndOffset), | |||
3790 | VAArgOverflowSize); | |||
3791 | VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize); | |||
3792 | IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize); | |||
3793 | if (MS.TrackOrigins) { | |||
3794 | VAArgTLSOriginCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize); | |||
3795 | IRB.CreateMemCpy(VAArgTLSOriginCopy, 8, MS.VAArgOriginTLS, 8, CopySize); | |||
3796 | } | |||
3797 | } | |||
3798 | ||||
3799 | // Instrument va_start. | |||
3800 | // Copy va_list shadow from the backup copy of the TLS contents. | |||
3801 | for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) { | |||
3802 | CallInst *OrigInst = VAStartInstrumentationList[i]; | |||
3803 | IRBuilder<> IRB(OrigInst->getNextNode()); | |||
3804 | Value *VAListTag = OrigInst->getArgOperand(0); | |||
3805 | ||||
3806 | Value *RegSaveAreaPtrPtr = IRB.CreateIntToPtr( | |||
3807 | IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
3808 | ConstantInt::get(MS.IntptrTy, 16)), | |||
3809 | PointerType::get(Type::getInt64PtrTy(*MS.C), 0)); | |||
3810 | Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr); | |||
3811 | Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr; | |||
3812 | unsigned Alignment = 16; | |||
3813 | std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) = | |||
3814 | MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(), | |||
3815 | Alignment, /*isStore*/ true); | |||
3816 | IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment, | |||
3817 | AMD64FpEndOffset); | |||
3818 | if (MS.TrackOrigins) | |||
3819 | IRB.CreateMemCpy(RegSaveAreaOriginPtr, Alignment, VAArgTLSOriginCopy, | |||
3820 | Alignment, AMD64FpEndOffset); | |||
3821 | Value *OverflowArgAreaPtrPtr = IRB.CreateIntToPtr( | |||
3822 | IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
3823 | ConstantInt::get(MS.IntptrTy, 8)), | |||
3824 | PointerType::get(Type::getInt64PtrTy(*MS.C), 0)); | |||
3825 | Value *OverflowArgAreaPtr = IRB.CreateLoad(OverflowArgAreaPtrPtr); | |||
3826 | Value *OverflowArgAreaShadowPtr, *OverflowArgAreaOriginPtr; | |||
3827 | std::tie(OverflowArgAreaShadowPtr, OverflowArgAreaOriginPtr) = | |||
3828 | MSV.getShadowOriginPtr(OverflowArgAreaPtr, IRB, IRB.getInt8Ty(), | |||
3829 | Alignment, /*isStore*/ true); | |||
3830 | Value *SrcPtr = IRB.CreateConstGEP1_32(IRB.getInt8Ty(), VAArgTLSCopy, | |||
3831 | AMD64FpEndOffset); | |||
3832 | IRB.CreateMemCpy(OverflowArgAreaShadowPtr, Alignment, SrcPtr, Alignment, | |||
3833 | VAArgOverflowSize); | |||
3834 | if (MS.TrackOrigins) { | |||
3835 | SrcPtr = IRB.CreateConstGEP1_32(IRB.getInt8Ty(), VAArgTLSOriginCopy, | |||
3836 | AMD64FpEndOffset); | |||
3837 | IRB.CreateMemCpy(OverflowArgAreaOriginPtr, Alignment, SrcPtr, Alignment, | |||
3838 | VAArgOverflowSize); | |||
3839 | } | |||
3840 | } | |||
3841 | } | |||
3842 | }; | |||
3843 | ||||
3844 | /// MIPS64-specific implementation of VarArgHelper. | |||
3845 | struct VarArgMIPS64Helper : public VarArgHelper { | |||
3846 | Function &F; | |||
3847 | MemorySanitizer &MS; | |||
3848 | MemorySanitizerVisitor &MSV; | |||
3849 | Value *VAArgTLSCopy = nullptr; | |||
3850 | Value *VAArgSize = nullptr; | |||
3851 | ||||
3852 | SmallVector<CallInst*, 16> VAStartInstrumentationList; | |||
3853 | ||||
3854 | VarArgMIPS64Helper(Function &F, MemorySanitizer &MS, | |||
3855 | MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {} | |||
3856 | ||||
3857 | void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override { | |||
3858 | unsigned VAArgOffset = 0; | |||
3859 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
3860 | for (CallSite::arg_iterator ArgIt = CS.arg_begin() + | |||
3861 | CS.getFunctionType()->getNumParams(), End = CS.arg_end(); | |||
3862 | ArgIt != End; ++ArgIt) { | |||
3863 | Triple TargetTriple(F.getParent()->getTargetTriple()); | |||
3864 | Value *A = *ArgIt; | |||
3865 | Value *Base; | |||
3866 | uint64_t ArgSize = DL.getTypeAllocSize(A->getType()); | |||
3867 | if (TargetTriple.getArch() == Triple::mips64) { | |||
3868 | // Adjusting the shadow for argument with size < 8 to match the placement | |||
3869 | // of bits in big endian system | |||
3870 | if (ArgSize < 8) | |||
3871 | VAArgOffset += (8 - ArgSize); | |||
3872 | } | |||
3873 | Base = getShadowPtrForVAArgument(A->getType(), IRB, VAArgOffset, ArgSize); | |||
3874 | VAArgOffset += ArgSize; | |||
3875 | VAArgOffset = alignTo(VAArgOffset, 8); | |||
3876 | if (!Base) | |||
3877 | continue; | |||
3878 | IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment); | |||
3879 | } | |||
3880 | ||||
3881 | Constant *TotalVAArgSize = ConstantInt::get(IRB.getInt64Ty(), VAArgOffset); | |||
3882 | // Here using VAArgOverflowSizeTLS as VAArgSizeTLS to avoid creation of | |||
3883 | // a new class member i.e. it is the total size of all VarArgs. | |||
3884 | IRB.CreateStore(TotalVAArgSize, MS.VAArgOverflowSizeTLS); | |||
3885 | } | |||
3886 | ||||
3887 | /// Compute the shadow address for a given va_arg. | |||
3888 | Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB, | |||
3889 | unsigned ArgOffset, unsigned ArgSize) { | |||
3890 | // Make sure we don't overflow __msan_va_arg_tls. | |||
3891 | if (ArgOffset + ArgSize > kParamTLSSize) | |||
3892 | return nullptr; | |||
3893 | Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy); | |||
3894 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
3895 | return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0), | |||
3896 | "_msarg"); | |||
3897 | } | |||
3898 | ||||
3899 | void visitVAStartInst(VAStartInst &I) override { | |||
3900 | IRBuilder<> IRB(&I); | |||
3901 | VAStartInstrumentationList.push_back(&I); | |||
3902 | Value *VAListTag = I.getArgOperand(0); | |||
3903 | Value *ShadowPtr, *OriginPtr; | |||
3904 | unsigned Alignment = 8; | |||
3905 | std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr( | |||
3906 | VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true); | |||
3907 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
3908 | /* size */ 8, Alignment, false); | |||
3909 | } | |||
3910 | ||||
3911 | void visitVACopyInst(VACopyInst &I) override { | |||
3912 | IRBuilder<> IRB(&I); | |||
3913 | VAStartInstrumentationList.push_back(&I); | |||
3914 | Value *VAListTag = I.getArgOperand(0); | |||
3915 | Value *ShadowPtr, *OriginPtr; | |||
3916 | unsigned Alignment = 8; | |||
3917 | std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr( | |||
3918 | VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true); | |||
3919 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
3920 | /* size */ 8, Alignment, false); | |||
3921 | } | |||
3922 | ||||
3923 | void finalizeInstrumentation() override { | |||
3924 | assert(!VAArgSize && !VAArgTLSCopy &&((!VAArgSize && !VAArgTLSCopy && "finalizeInstrumentation called twice" ) ? static_cast<void> (0) : __assert_fail ("!VAArgSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3925, __PRETTY_FUNCTION__)) | |||
3925 | "finalizeInstrumentation called twice")((!VAArgSize && !VAArgTLSCopy && "finalizeInstrumentation called twice" ) ? static_cast<void> (0) : __assert_fail ("!VAArgSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 3925, __PRETTY_FUNCTION__)); | |||
3926 | IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI()); | |||
3927 | VAArgSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS); | |||
3928 | Value *CopySize = IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, 0), | |||
3929 | VAArgSize); | |||
3930 | ||||
3931 | if (!VAStartInstrumentationList.empty()) { | |||
3932 | // If there is a va_start in this function, make a backup copy of | |||
3933 | // va_arg_tls somewhere in the function entry block. | |||
3934 | VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize); | |||
3935 | IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize); | |||
3936 | } | |||
3937 | ||||
3938 | // Instrument va_start. | |||
3939 | // Copy va_list shadow from the backup copy of the TLS contents. | |||
3940 | for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) { | |||
3941 | CallInst *OrigInst = VAStartInstrumentationList[i]; | |||
3942 | IRBuilder<> IRB(OrigInst->getNextNode()); | |||
3943 | Value *VAListTag = OrigInst->getArgOperand(0); | |||
3944 | Value *RegSaveAreaPtrPtr = | |||
3945 | IRB.CreateIntToPtr(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
3946 | PointerType::get(Type::getInt64PtrTy(*MS.C), 0)); | |||
3947 | Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr); | |||
3948 | Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr; | |||
3949 | unsigned Alignment = 8; | |||
3950 | std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) = | |||
3951 | MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(), | |||
3952 | Alignment, /*isStore*/ true); | |||
3953 | IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment, | |||
3954 | CopySize); | |||
3955 | } | |||
3956 | } | |||
3957 | }; | |||
3958 | ||||
3959 | /// AArch64-specific implementation of VarArgHelper. | |||
3960 | struct VarArgAArch64Helper : public VarArgHelper { | |||
3961 | static const unsigned kAArch64GrArgSize = 64; | |||
3962 | static const unsigned kAArch64VrArgSize = 128; | |||
3963 | ||||
3964 | static const unsigned AArch64GrBegOffset = 0; | |||
3965 | static const unsigned AArch64GrEndOffset = kAArch64GrArgSize; | |||
3966 | // Make VR space aligned to 16 bytes. | |||
3967 | static const unsigned AArch64VrBegOffset = AArch64GrEndOffset; | |||
3968 | static const unsigned AArch64VrEndOffset = AArch64VrBegOffset | |||
3969 | + kAArch64VrArgSize; | |||
3970 | static const unsigned AArch64VAEndOffset = AArch64VrEndOffset; | |||
3971 | ||||
3972 | Function &F; | |||
3973 | MemorySanitizer &MS; | |||
3974 | MemorySanitizerVisitor &MSV; | |||
3975 | Value *VAArgTLSCopy = nullptr; | |||
3976 | Value *VAArgOverflowSize = nullptr; | |||
3977 | ||||
3978 | SmallVector<CallInst*, 16> VAStartInstrumentationList; | |||
3979 | ||||
3980 | enum ArgKind { AK_GeneralPurpose, AK_FloatingPoint, AK_Memory }; | |||
3981 | ||||
3982 | VarArgAArch64Helper(Function &F, MemorySanitizer &MS, | |||
3983 | MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {} | |||
3984 | ||||
3985 | ArgKind classifyArgument(Value* arg) { | |||
3986 | Type *T = arg->getType(); | |||
3987 | if (T->isFPOrFPVectorTy()) | |||
3988 | return AK_FloatingPoint; | |||
3989 | if ((T->isIntegerTy() && T->getPrimitiveSizeInBits() <= 64) | |||
3990 | || (T->isPointerTy())) | |||
3991 | return AK_GeneralPurpose; | |||
3992 | return AK_Memory; | |||
3993 | } | |||
3994 | ||||
3995 | // The instrumentation stores the argument shadow in a non ABI-specific | |||
3996 | // format because it does not know which argument is named (since Clang, | |||
3997 | // like x86_64 case, lowers the va_args in the frontend and this pass only | |||
3998 | // sees the low level code that deals with va_list internals). | |||
3999 | // The first seven GR registers are saved in the first 56 bytes of the | |||
4000 | // va_arg tls arra, followers by the first 8 FP/SIMD registers, and then | |||
4001 | // the remaining arguments. | |||
4002 | // Using constant offset within the va_arg TLS array allows fast copy | |||
4003 | // in the finalize instrumentation. | |||
4004 | void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override { | |||
4005 | unsigned GrOffset = AArch64GrBegOffset; | |||
4006 | unsigned VrOffset = AArch64VrBegOffset; | |||
4007 | unsigned OverflowOffset = AArch64VAEndOffset; | |||
4008 | ||||
4009 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
4010 | for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end(); | |||
4011 | ArgIt != End; ++ArgIt) { | |||
4012 | Value *A = *ArgIt; | |||
4013 | unsigned ArgNo = CS.getArgumentNo(ArgIt); | |||
4014 | bool IsFixed = ArgNo < CS.getFunctionType()->getNumParams(); | |||
4015 | ArgKind AK = classifyArgument(A); | |||
4016 | if (AK == AK_GeneralPurpose && GrOffset >= AArch64GrEndOffset) | |||
4017 | AK = AK_Memory; | |||
4018 | if (AK == AK_FloatingPoint && VrOffset >= AArch64VrEndOffset) | |||
4019 | AK = AK_Memory; | |||
4020 | Value *Base; | |||
4021 | switch (AK) { | |||
4022 | case AK_GeneralPurpose: | |||
4023 | Base = getShadowPtrForVAArgument(A->getType(), IRB, GrOffset, 8); | |||
4024 | GrOffset += 8; | |||
4025 | break; | |||
4026 | case AK_FloatingPoint: | |||
4027 | Base = getShadowPtrForVAArgument(A->getType(), IRB, VrOffset, 8); | |||
4028 | VrOffset += 16; | |||
4029 | break; | |||
4030 | case AK_Memory: | |||
4031 | // Don't count fixed arguments in the overflow area - va_start will | |||
4032 | // skip right over them. | |||
4033 | if (IsFixed) | |||
4034 | continue; | |||
4035 | uint64_t ArgSize = DL.getTypeAllocSize(A->getType()); | |||
4036 | Base = getShadowPtrForVAArgument(A->getType(), IRB, OverflowOffset, | |||
4037 | alignTo(ArgSize, 8)); | |||
4038 | OverflowOffset += alignTo(ArgSize, 8); | |||
4039 | break; | |||
4040 | } | |||
4041 | // Count Gp/Vr fixed arguments to their respective offsets, but don't | |||
4042 | // bother to actually store a shadow. | |||
4043 | if (IsFixed) | |||
4044 | continue; | |||
4045 | if (!Base) | |||
4046 | continue; | |||
4047 | IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment); | |||
4048 | } | |||
4049 | Constant *OverflowSize = | |||
4050 | ConstantInt::get(IRB.getInt64Ty(), OverflowOffset - AArch64VAEndOffset); | |||
4051 | IRB.CreateStore(OverflowSize, MS.VAArgOverflowSizeTLS); | |||
4052 | } | |||
4053 | ||||
4054 | /// Compute the shadow address for a given va_arg. | |||
4055 | Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB, | |||
4056 | unsigned ArgOffset, unsigned ArgSize) { | |||
4057 | // Make sure we don't overflow __msan_va_arg_tls. | |||
4058 | if (ArgOffset + ArgSize > kParamTLSSize) | |||
4059 | return nullptr; | |||
4060 | Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy); | |||
4061 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
4062 | return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0), | |||
4063 | "_msarg"); | |||
4064 | } | |||
4065 | ||||
4066 | void visitVAStartInst(VAStartInst &I) override { | |||
4067 | IRBuilder<> IRB(&I); | |||
4068 | VAStartInstrumentationList.push_back(&I); | |||
4069 | Value *VAListTag = I.getArgOperand(0); | |||
4070 | Value *ShadowPtr, *OriginPtr; | |||
4071 | unsigned Alignment = 8; | |||
4072 | std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr( | |||
4073 | VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true); | |||
4074 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
4075 | /* size */ 32, Alignment, false); | |||
4076 | } | |||
4077 | ||||
4078 | void visitVACopyInst(VACopyInst &I) override { | |||
4079 | IRBuilder<> IRB(&I); | |||
4080 | VAStartInstrumentationList.push_back(&I); | |||
4081 | Value *VAListTag = I.getArgOperand(0); | |||
4082 | Value *ShadowPtr, *OriginPtr; | |||
4083 | unsigned Alignment = 8; | |||
4084 | std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr( | |||
4085 | VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true); | |||
4086 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
4087 | /* size */ 32, Alignment, false); | |||
4088 | } | |||
4089 | ||||
4090 | // Retrieve a va_list field of 'void*' size. | |||
4091 | Value* getVAField64(IRBuilder<> &IRB, Value *VAListTag, int offset) { | |||
4092 | Value *SaveAreaPtrPtr = | |||
4093 | IRB.CreateIntToPtr( | |||
4094 | IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
4095 | ConstantInt::get(MS.IntptrTy, offset)), | |||
4096 | Type::getInt64PtrTy(*MS.C)); | |||
4097 | return IRB.CreateLoad(SaveAreaPtrPtr); | |||
4098 | } | |||
4099 | ||||
4100 | // Retrieve a va_list field of 'int' size. | |||
4101 | Value* getVAField32(IRBuilder<> &IRB, Value *VAListTag, int offset) { | |||
4102 | Value *SaveAreaPtr = | |||
4103 | IRB.CreateIntToPtr( | |||
4104 | IRB.CreateAdd(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
4105 | ConstantInt::get(MS.IntptrTy, offset)), | |||
4106 | Type::getInt32PtrTy(*MS.C)); | |||
4107 | Value *SaveArea32 = IRB.CreateLoad(SaveAreaPtr); | |||
4108 | return IRB.CreateSExt(SaveArea32, MS.IntptrTy); | |||
4109 | } | |||
4110 | ||||
4111 | void finalizeInstrumentation() override { | |||
4112 | assert(!VAArgOverflowSize && !VAArgTLSCopy &&((!VAArgOverflowSize && !VAArgTLSCopy && "finalizeInstrumentation called twice" ) ? static_cast<void> (0) : __assert_fail ("!VAArgOverflowSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 4113, __PRETTY_FUNCTION__)) | |||
4113 | "finalizeInstrumentation called twice")((!VAArgOverflowSize && !VAArgTLSCopy && "finalizeInstrumentation called twice" ) ? static_cast<void> (0) : __assert_fail ("!VAArgOverflowSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 4113, __PRETTY_FUNCTION__)); | |||
4114 | if (!VAStartInstrumentationList.empty()) { | |||
4115 | // If there is a va_start in this function, make a backup copy of | |||
4116 | // va_arg_tls somewhere in the function entry block. | |||
4117 | IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI()); | |||
4118 | VAArgOverflowSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS); | |||
4119 | Value *CopySize = | |||
4120 | IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, AArch64VAEndOffset), | |||
4121 | VAArgOverflowSize); | |||
4122 | VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize); | |||
4123 | IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize); | |||
4124 | } | |||
4125 | ||||
4126 | Value *GrArgSize = ConstantInt::get(MS.IntptrTy, kAArch64GrArgSize); | |||
4127 | Value *VrArgSize = ConstantInt::get(MS.IntptrTy, kAArch64VrArgSize); | |||
4128 | ||||
4129 | // Instrument va_start, copy va_list shadow from the backup copy of | |||
4130 | // the TLS contents. | |||
4131 | for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) { | |||
4132 | CallInst *OrigInst = VAStartInstrumentationList[i]; | |||
4133 | IRBuilder<> IRB(OrigInst->getNextNode()); | |||
4134 | ||||
4135 | Value *VAListTag = OrigInst->getArgOperand(0); | |||
4136 | ||||
4137 | // The variadic ABI for AArch64 creates two areas to save the incoming | |||
4138 | // argument registers (one for 64-bit general register xn-x7 and another | |||
4139 | // for 128-bit FP/SIMD vn-v7). | |||
4140 | // We need then to propagate the shadow arguments on both regions | |||
4141 | // 'va::__gr_top + va::__gr_offs' and 'va::__vr_top + va::__vr_offs'. | |||
4142 | // The remaning arguments are saved on shadow for 'va::stack'. | |||
4143 | // One caveat is it requires only to propagate the non-named arguments, | |||
4144 | // however on the call site instrumentation 'all' the arguments are | |||
4145 | // saved. So to copy the shadow values from the va_arg TLS array | |||
4146 | // we need to adjust the offset for both GR and VR fields based on | |||
4147 | // the __{gr,vr}_offs value (since they are stores based on incoming | |||
4148 | // named arguments). | |||
4149 | ||||
4150 | // Read the stack pointer from the va_list. | |||
4151 | Value *StackSaveAreaPtr = getVAField64(IRB, VAListTag, 0); | |||
4152 | ||||
4153 | // Read both the __gr_top and __gr_off and add them up. | |||
4154 | Value *GrTopSaveAreaPtr = getVAField64(IRB, VAListTag, 8); | |||
4155 | Value *GrOffSaveArea = getVAField32(IRB, VAListTag, 24); | |||
4156 | ||||
4157 | Value *GrRegSaveAreaPtr = IRB.CreateAdd(GrTopSaveAreaPtr, GrOffSaveArea); | |||
4158 | ||||
4159 | // Read both the __vr_top and __vr_off and add them up. | |||
4160 | Value *VrTopSaveAreaPtr = getVAField64(IRB, VAListTag, 16); | |||
4161 | Value *VrOffSaveArea = getVAField32(IRB, VAListTag, 28); | |||
4162 | ||||
4163 | Value *VrRegSaveAreaPtr = IRB.CreateAdd(VrTopSaveAreaPtr, VrOffSaveArea); | |||
4164 | ||||
4165 | // It does not know how many named arguments is being used and, on the | |||
4166 | // callsite all the arguments were saved. Since __gr_off is defined as | |||
4167 | // '0 - ((8 - named_gr) * 8)', the idea is to just propagate the variadic | |||
4168 | // argument by ignoring the bytes of shadow from named arguments. | |||
4169 | Value *GrRegSaveAreaShadowPtrOff = | |||
4170 | IRB.CreateAdd(GrArgSize, GrOffSaveArea); | |||
4171 | ||||
4172 | Value *GrRegSaveAreaShadowPtr = | |||
4173 | MSV.getShadowOriginPtr(GrRegSaveAreaPtr, IRB, IRB.getInt8Ty(), | |||
4174 | /*Alignment*/ 8, /*isStore*/ true) | |||
4175 | .first; | |||
4176 | ||||
4177 | Value *GrSrcPtr = IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy, | |||
4178 | GrRegSaveAreaShadowPtrOff); | |||
4179 | Value *GrCopySize = IRB.CreateSub(GrArgSize, GrRegSaveAreaShadowPtrOff); | |||
4180 | ||||
4181 | IRB.CreateMemCpy(GrRegSaveAreaShadowPtr, 8, GrSrcPtr, 8, GrCopySize); | |||
4182 | ||||
4183 | // Again, but for FP/SIMD values. | |||
4184 | Value *VrRegSaveAreaShadowPtrOff = | |||
4185 | IRB.CreateAdd(VrArgSize, VrOffSaveArea); | |||
4186 | ||||
4187 | Value *VrRegSaveAreaShadowPtr = | |||
4188 | MSV.getShadowOriginPtr(VrRegSaveAreaPtr, IRB, IRB.getInt8Ty(), | |||
4189 | /*Alignment*/ 8, /*isStore*/ true) | |||
4190 | .first; | |||
4191 | ||||
4192 | Value *VrSrcPtr = IRB.CreateInBoundsGEP( | |||
4193 | IRB.getInt8Ty(), | |||
4194 | IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy, | |||
4195 | IRB.getInt32(AArch64VrBegOffset)), | |||
4196 | VrRegSaveAreaShadowPtrOff); | |||
4197 | Value *VrCopySize = IRB.CreateSub(VrArgSize, VrRegSaveAreaShadowPtrOff); | |||
4198 | ||||
4199 | IRB.CreateMemCpy(VrRegSaveAreaShadowPtr, 8, VrSrcPtr, 8, VrCopySize); | |||
4200 | ||||
4201 | // And finally for remaining arguments. | |||
4202 | Value *StackSaveAreaShadowPtr = | |||
4203 | MSV.getShadowOriginPtr(StackSaveAreaPtr, IRB, IRB.getInt8Ty(), | |||
4204 | /*Alignment*/ 16, /*isStore*/ true) | |||
4205 | .first; | |||
4206 | ||||
4207 | Value *StackSrcPtr = | |||
4208 | IRB.CreateInBoundsGEP(IRB.getInt8Ty(), VAArgTLSCopy, | |||
4209 | IRB.getInt32(AArch64VAEndOffset)); | |||
4210 | ||||
4211 | IRB.CreateMemCpy(StackSaveAreaShadowPtr, 16, StackSrcPtr, 16, | |||
4212 | VAArgOverflowSize); | |||
4213 | } | |||
4214 | } | |||
4215 | }; | |||
4216 | ||||
4217 | /// PowerPC64-specific implementation of VarArgHelper. | |||
4218 | struct VarArgPowerPC64Helper : public VarArgHelper { | |||
4219 | Function &F; | |||
4220 | MemorySanitizer &MS; | |||
4221 | MemorySanitizerVisitor &MSV; | |||
4222 | Value *VAArgTLSCopy = nullptr; | |||
4223 | Value *VAArgSize = nullptr; | |||
4224 | ||||
4225 | SmallVector<CallInst*, 16> VAStartInstrumentationList; | |||
4226 | ||||
4227 | VarArgPowerPC64Helper(Function &F, MemorySanitizer &MS, | |||
4228 | MemorySanitizerVisitor &MSV) : F(F), MS(MS), MSV(MSV) {} | |||
4229 | ||||
4230 | void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override { | |||
4231 | // For PowerPC, we need to deal with alignment of stack arguments - | |||
4232 | // they are mostly aligned to 8 bytes, but vectors and i128 arrays | |||
4233 | // are aligned to 16 bytes, byvals can be aligned to 8 or 16 bytes, | |||
4234 | // and QPX vectors are aligned to 32 bytes. For that reason, we | |||
4235 | // compute current offset from stack pointer (which is always properly | |||
4236 | // aligned), and offset for the first vararg, then subtract them. | |||
4237 | unsigned VAArgBase; | |||
4238 | Triple TargetTriple(F.getParent()->getTargetTriple()); | |||
4239 | // Parameter save area starts at 48 bytes from frame pointer for ABIv1, | |||
4240 | // and 32 bytes for ABIv2. This is usually determined by target | |||
4241 | // endianness, but in theory could be overriden by function attribute. | |||
4242 | // For simplicity, we ignore it here (it'd only matter for QPX vectors). | |||
4243 | if (TargetTriple.getArch() == Triple::ppc64) | |||
4244 | VAArgBase = 48; | |||
4245 | else | |||
4246 | VAArgBase = 32; | |||
4247 | unsigned VAArgOffset = VAArgBase; | |||
4248 | const DataLayout &DL = F.getParent()->getDataLayout(); | |||
4249 | for (CallSite::arg_iterator ArgIt = CS.arg_begin(), End = CS.arg_end(); | |||
4250 | ArgIt != End; ++ArgIt) { | |||
4251 | Value *A = *ArgIt; | |||
4252 | unsigned ArgNo = CS.getArgumentNo(ArgIt); | |||
4253 | bool IsFixed = ArgNo < CS.getFunctionType()->getNumParams(); | |||
4254 | bool IsByVal = CS.paramHasAttr(ArgNo, Attribute::ByVal); | |||
4255 | if (IsByVal) { | |||
4256 | assert(A->getType()->isPointerTy())((A->getType()->isPointerTy()) ? static_cast<void> (0) : __assert_fail ("A->getType()->isPointerTy()", "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 4256, __PRETTY_FUNCTION__)); | |||
4257 | Type *RealTy = A->getType()->getPointerElementType(); | |||
4258 | uint64_t ArgSize = DL.getTypeAllocSize(RealTy); | |||
4259 | uint64_t ArgAlign = CS.getParamAlignment(ArgNo); | |||
4260 | if (ArgAlign < 8) | |||
4261 | ArgAlign = 8; | |||
4262 | VAArgOffset = alignTo(VAArgOffset, ArgAlign); | |||
4263 | if (!IsFixed) { | |||
4264 | Value *Base = getShadowPtrForVAArgument( | |||
4265 | RealTy, IRB, VAArgOffset - VAArgBase, ArgSize); | |||
4266 | if (Base) { | |||
4267 | Value *AShadowPtr, *AOriginPtr; | |||
4268 | std::tie(AShadowPtr, AOriginPtr) = | |||
4269 | MSV.getShadowOriginPtr(A, IRB, IRB.getInt8Ty(), | |||
4270 | kShadowTLSAlignment, /*isStore*/ false); | |||
4271 | ||||
4272 | IRB.CreateMemCpy(Base, kShadowTLSAlignment, AShadowPtr, | |||
4273 | kShadowTLSAlignment, ArgSize); | |||
4274 | } | |||
4275 | } | |||
4276 | VAArgOffset += alignTo(ArgSize, 8); | |||
4277 | } else { | |||
4278 | Value *Base; | |||
4279 | uint64_t ArgSize = DL.getTypeAllocSize(A->getType()); | |||
4280 | uint64_t ArgAlign = 8; | |||
4281 | if (A->getType()->isArrayTy()) { | |||
4282 | // Arrays are aligned to element size, except for long double | |||
4283 | // arrays, which are aligned to 8 bytes. | |||
4284 | Type *ElementTy = A->getType()->getArrayElementType(); | |||
4285 | if (!ElementTy->isPPC_FP128Ty()) | |||
4286 | ArgAlign = DL.getTypeAllocSize(ElementTy); | |||
4287 | } else if (A->getType()->isVectorTy()) { | |||
4288 | // Vectors are naturally aligned. | |||
4289 | ArgAlign = DL.getTypeAllocSize(A->getType()); | |||
4290 | } | |||
4291 | if (ArgAlign < 8) | |||
4292 | ArgAlign = 8; | |||
4293 | VAArgOffset = alignTo(VAArgOffset, ArgAlign); | |||
4294 | if (DL.isBigEndian()) { | |||
4295 | // Adjusting the shadow for argument with size < 8 to match the placement | |||
4296 | // of bits in big endian system | |||
4297 | if (ArgSize < 8) | |||
4298 | VAArgOffset += (8 - ArgSize); | |||
4299 | } | |||
4300 | if (!IsFixed) { | |||
4301 | Base = getShadowPtrForVAArgument(A->getType(), IRB, | |||
4302 | VAArgOffset - VAArgBase, ArgSize); | |||
4303 | if (Base) | |||
4304 | IRB.CreateAlignedStore(MSV.getShadow(A), Base, kShadowTLSAlignment); | |||
4305 | } | |||
4306 | VAArgOffset += ArgSize; | |||
4307 | VAArgOffset = alignTo(VAArgOffset, 8); | |||
4308 | } | |||
4309 | if (IsFixed) | |||
4310 | VAArgBase = VAArgOffset; | |||
4311 | } | |||
4312 | ||||
4313 | Constant *TotalVAArgSize = ConstantInt::get(IRB.getInt64Ty(), | |||
4314 | VAArgOffset - VAArgBase); | |||
4315 | // Here using VAArgOverflowSizeTLS as VAArgSizeTLS to avoid creation of | |||
4316 | // a new class member i.e. it is the total size of all VarArgs. | |||
4317 | IRB.CreateStore(TotalVAArgSize, MS.VAArgOverflowSizeTLS); | |||
4318 | } | |||
4319 | ||||
4320 | /// Compute the shadow address for a given va_arg. | |||
4321 | Value *getShadowPtrForVAArgument(Type *Ty, IRBuilder<> &IRB, | |||
4322 | unsigned ArgOffset, unsigned ArgSize) { | |||
4323 | // Make sure we don't overflow __msan_va_arg_tls. | |||
4324 | if (ArgOffset + ArgSize > kParamTLSSize) | |||
4325 | return nullptr; | |||
4326 | Value *Base = IRB.CreatePointerCast(MS.VAArgTLS, MS.IntptrTy); | |||
4327 | Base = IRB.CreateAdd(Base, ConstantInt::get(MS.IntptrTy, ArgOffset)); | |||
4328 | return IRB.CreateIntToPtr(Base, PointerType::get(MSV.getShadowTy(Ty), 0), | |||
4329 | "_msarg"); | |||
4330 | } | |||
4331 | ||||
4332 | void visitVAStartInst(VAStartInst &I) override { | |||
4333 | IRBuilder<> IRB(&I); | |||
4334 | VAStartInstrumentationList.push_back(&I); | |||
4335 | Value *VAListTag = I.getArgOperand(0); | |||
4336 | Value *ShadowPtr, *OriginPtr; | |||
4337 | unsigned Alignment = 8; | |||
4338 | std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr( | |||
4339 | VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true); | |||
4340 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
4341 | /* size */ 8, Alignment, false); | |||
4342 | } | |||
4343 | ||||
4344 | void visitVACopyInst(VACopyInst &I) override { | |||
4345 | IRBuilder<> IRB(&I); | |||
4346 | Value *VAListTag = I.getArgOperand(0); | |||
4347 | Value *ShadowPtr, *OriginPtr; | |||
4348 | unsigned Alignment = 8; | |||
4349 | std::tie(ShadowPtr, OriginPtr) = MSV.getShadowOriginPtr( | |||
4350 | VAListTag, IRB, IRB.getInt8Ty(), Alignment, /*isStore*/ true); | |||
4351 | // Unpoison the whole __va_list_tag. | |||
4352 | // FIXME: magic ABI constants. | |||
4353 | IRB.CreateMemSet(ShadowPtr, Constant::getNullValue(IRB.getInt8Ty()), | |||
4354 | /* size */ 8, Alignment, false); | |||
4355 | } | |||
4356 | ||||
4357 | void finalizeInstrumentation() override { | |||
4358 | assert(!VAArgSize && !VAArgTLSCopy &&((!VAArgSize && !VAArgTLSCopy && "finalizeInstrumentation called twice" ) ? static_cast<void> (0) : __assert_fail ("!VAArgSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 4359, __PRETTY_FUNCTION__)) | |||
4359 | "finalizeInstrumentation called twice")((!VAArgSize && !VAArgTLSCopy && "finalizeInstrumentation called twice" ) ? static_cast<void> (0) : __assert_fail ("!VAArgSize && !VAArgTLSCopy && \"finalizeInstrumentation called twice\"" , "/build/llvm-toolchain-snapshot-8~svn350071/lib/Transforms/Instrumentation/MemorySanitizer.cpp" , 4359, __PRETTY_FUNCTION__)); | |||
4360 | IRBuilder<> IRB(MSV.ActualFnStart->getFirstNonPHI()); | |||
4361 | VAArgSize = IRB.CreateLoad(MS.VAArgOverflowSizeTLS); | |||
4362 | Value *CopySize = IRB.CreateAdd(ConstantInt::get(MS.IntptrTy, 0), | |||
4363 | VAArgSize); | |||
4364 | ||||
4365 | if (!VAStartInstrumentationList.empty()) { | |||
4366 | // If there is a va_start in this function, make a backup copy of | |||
4367 | // va_arg_tls somewhere in the function entry block. | |||
4368 | VAArgTLSCopy = IRB.CreateAlloca(Type::getInt8Ty(*MS.C), CopySize); | |||
4369 | IRB.CreateMemCpy(VAArgTLSCopy, 8, MS.VAArgTLS, 8, CopySize); | |||
4370 | } | |||
4371 | ||||
4372 | // Instrument va_start. | |||
4373 | // Copy va_list shadow from the backup copy of the TLS contents. | |||
4374 | for (size_t i = 0, n = VAStartInstrumentationList.size(); i < n; i++) { | |||
4375 | CallInst *OrigInst = VAStartInstrumentationList[i]; | |||
4376 | IRBuilder<> IRB(OrigInst->getNextNode()); | |||
4377 | Value *VAListTag = OrigInst->getArgOperand(0); | |||
4378 | Value *RegSaveAreaPtrPtr = | |||
4379 | IRB.CreateIntToPtr(IRB.CreatePtrToInt(VAListTag, MS.IntptrTy), | |||
4380 | PointerType::get(Type::getInt64PtrTy(*MS.C), 0)); | |||
4381 | Value *RegSaveAreaPtr = IRB.CreateLoad(RegSaveAreaPtrPtr); | |||
4382 | Value *RegSaveAreaShadowPtr, *RegSaveAreaOriginPtr; | |||
4383 | unsigned Alignment = 8; | |||
4384 | std::tie(RegSaveAreaShadowPtr, RegSaveAreaOriginPtr) = | |||
4385 | MSV.getShadowOriginPtr(RegSaveAreaPtr, IRB, IRB.getInt8Ty(), | |||
4386 | Alignment, /*isStore*/ true); | |||
4387 | IRB.CreateMemCpy(RegSaveAreaShadowPtr, Alignment, VAArgTLSCopy, Alignment, | |||
4388 | CopySize); | |||
4389 | } | |||
4390 | } | |||
4391 | }; | |||
4392 | ||||
4393 | /// A no-op implementation of VarArgHelper. | |||
4394 | struct VarArgNoOpHelper : public VarArgHelper { | |||
4395 | VarArgNoOpHelper(Function &F, MemorySanitizer &MS, | |||
4396 | MemorySanitizerVisitor &MSV) {} | |||
4397 | ||||
4398 | void visitCallSite(CallSite &CS, IRBuilder<> &IRB) override {} | |||
4399 | ||||
4400 | void visitVAStartInst(VAStartInst &I) override {} | |||
4401 | ||||
4402 | void visitVACopyInst(VACopyInst &I) override {} | |||
4403 | ||||
4404 | void finalizeInstrumentation() override {} | |||
4405 | }; | |||
4406 | ||||
4407 | } // end anonymous namespace | |||
4408 | ||||
4409 | static VarArgHelper *CreateVarArgHelper(Function &Func, MemorySanitizer &Msan, | |||
4410 | MemorySanitizerVisitor &Visitor) { | |||
4411 | // VarArg handling is only implemented on AMD64. False positives are possible | |||
4412 | // on other platforms. | |||
4413 | Triple TargetTriple(Func.getParent()->getTargetTriple()); | |||
4414 | if (TargetTriple.getArch() == Triple::x86_64) | |||
4415 | return new VarArgAMD64Helper(Func, Msan, Visitor); | |||
4416 | else if (TargetTriple.isMIPS64()) | |||
4417 | return new VarArgMIPS64Helper(Func, Msan, Visitor); | |||
4418 | else if (TargetTriple.getArch() == Triple::aarch64) | |||
4419 | return new VarArgAArch64Helper(Func, Msan, Visitor); | |||
4420 | else if (TargetTriple.getArch() == Triple::ppc64 || | |||
4421 | TargetTriple.getArch() == Triple::ppc64le) | |||
4422 | return new VarArgPowerPC64Helper(Func, Msan, Visitor); | |||
4423 | else | |||
4424 | return new VarArgNoOpHelper(Func, Msan, Visitor); | |||
4425 | } | |||
4426 | ||||
4427 | bool MemorySanitizer::runOnFunction(Function &F) { | |||
4428 | if (!CompileKernel && (&F == MsanCtorFunction)) | |||
4429 | return false; | |||
4430 | MemorySanitizerVisitor Visitor(F, *this); | |||
4431 | ||||
4432 | // Clear out readonly/readnone attributes. | |||
4433 | AttrBuilder B; | |||
4434 | B.addAttribute(Attribute::ReadOnly) | |||
4435 | .addAttribute(Attribute::ReadNone); | |||
4436 | F.removeAttributes(AttributeList::FunctionIndex, B); | |||
4437 | ||||
4438 | return Visitor.runOnFunction(); | |||
4439 | } |