1 //===-- msan.cpp ----------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is a part of MemorySanitizer.
10 //
11 // MemorySanitizer runtime.
12 //===----------------------------------------------------------------------===//
13
14 #include "msan.h"
15
16 #include "msan_chained_origin_depot.h"
17 #include "msan_origin.h"
18 #include "msan_poisoning.h"
19 #include "msan_report.h"
20 #include "msan_thread.h"
21 #include "sanitizer_common/sanitizer_atomic.h"
22 #include "sanitizer_common/sanitizer_common.h"
23 #include "sanitizer_common/sanitizer_flag_parser.h"
24 #include "sanitizer_common/sanitizer_flags.h"
25 #include "sanitizer_common/sanitizer_interface_internal.h"
26 #include "sanitizer_common/sanitizer_libc.h"
27 #include "sanitizer_common/sanitizer_procmaps.h"
28 #include "sanitizer_common/sanitizer_stackdepot.h"
29 #include "sanitizer_common/sanitizer_stacktrace.h"
30 #include "sanitizer_common/sanitizer_symbolizer.h"
31 #include "ubsan/ubsan_flags.h"
32 #include "ubsan/ubsan_init.h"
33
34 // ACHTUNG! No system header includes in this file.
35
36 using namespace __sanitizer;
37
38 // Globals.
39 static THREADLOCAL int msan_expect_umr = 0;
40 static THREADLOCAL int msan_expected_umr_found = 0;
41
42 // Function argument shadow. Each argument starts at the next available 8-byte
43 // aligned address.
44 SANITIZER_INTERFACE_ATTRIBUTE
45 THREADLOCAL u64 __msan_param_tls[kMsanParamTlsSize / sizeof(u64)];
46
47 // Function argument origin. Each argument starts at the same offset as the
48 // corresponding shadow in (__msan_param_tls). Slightly weird, but changing this
49 // would break compatibility with older prebuilt binaries.
50 SANITIZER_INTERFACE_ATTRIBUTE
51 THREADLOCAL u32 __msan_param_origin_tls[kMsanParamTlsSize / sizeof(u32)];
52
53 SANITIZER_INTERFACE_ATTRIBUTE
54 THREADLOCAL u64 __msan_retval_tls[kMsanRetvalTlsSize / sizeof(u64)];
55
56 SANITIZER_INTERFACE_ATTRIBUTE
57 THREADLOCAL u32 __msan_retval_origin_tls;
58
59 SANITIZER_INTERFACE_ATTRIBUTE
60 ALIGNED(16) THREADLOCAL u64 __msan_va_arg_tls[kMsanParamTlsSize / sizeof(u64)];
61
62 SANITIZER_INTERFACE_ATTRIBUTE
63 ALIGNED(16)
64 THREADLOCAL u32 __msan_va_arg_origin_tls[kMsanParamTlsSize / sizeof(u32)];
65
66 SANITIZER_INTERFACE_ATTRIBUTE
67 THREADLOCAL u64 __msan_va_arg_overflow_size_tls;
68
69 SANITIZER_INTERFACE_ATTRIBUTE
70 THREADLOCAL u32 __msan_origin_tls;
71
72 extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_track_origins;
73
__msan_get_track_origins()74 int __msan_get_track_origins() {
75 return &__msan_track_origins ? __msan_track_origins : 0;
76 }
77
78 extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_keep_going;
79
80 namespace __msan {
81
82 static THREADLOCAL int is_in_symbolizer_or_unwinder;
EnterSymbolizerOrUnwider()83 static void EnterSymbolizerOrUnwider() { ++is_in_symbolizer_or_unwinder; }
ExitSymbolizerOrUnwider()84 static void ExitSymbolizerOrUnwider() { --is_in_symbolizer_or_unwinder; }
IsInSymbolizerOrUnwider()85 bool IsInSymbolizerOrUnwider() { return is_in_symbolizer_or_unwinder; }
86
87 struct UnwinderScope {
UnwinderScope__msan::UnwinderScope88 UnwinderScope() { EnterSymbolizerOrUnwider(); }
~UnwinderScope__msan::UnwinderScope89 ~UnwinderScope() { ExitSymbolizerOrUnwider(); }
90 };
91
92 static Flags msan_flags;
93
flags()94 Flags *flags() { return &msan_flags; }
95
96 int msan_inited = 0;
97 bool msan_init_is_running;
98
99 int msan_report_count = 0;
100
101 // Array of stack origins.
102 // FIXME: make it resizable.
103 static const uptr kNumStackOriginDescrs = 1024 * 1024;
104 static const char *StackOriginDescr[kNumStackOriginDescrs];
105 static uptr StackOriginPC[kNumStackOriginDescrs];
106 static atomic_uint32_t NumStackOriginDescrs;
107
SetDefaults()108 void Flags::SetDefaults() {
109 #define MSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
110 #include "msan_flags.inc"
111 #undef MSAN_FLAG
112 }
113
114 // keep_going is an old name for halt_on_error,
115 // and it has inverse meaning.
116 class FlagHandlerKeepGoing final : public FlagHandlerBase {
117 bool *halt_on_error_;
118
119 public:
FlagHandlerKeepGoing(bool * halt_on_error)120 explicit FlagHandlerKeepGoing(bool *halt_on_error)
121 : halt_on_error_(halt_on_error) {}
Parse(const char * value)122 bool Parse(const char *value) final {
123 bool tmp;
124 FlagHandler<bool> h(&tmp);
125 if (!h.Parse(value)) return false;
126 *halt_on_error_ = !tmp;
127 return true;
128 }
Format(char * buffer,uptr size)129 bool Format(char *buffer, uptr size) final {
130 const char *keep_going_str = (*halt_on_error_) ? "false" : "true";
131 return FormatString(buffer, size, keep_going_str);
132 }
133 };
134
RegisterMsanFlags(FlagParser * parser,Flags * f)135 static void RegisterMsanFlags(FlagParser *parser, Flags *f) {
136 #define MSAN_FLAG(Type, Name, DefaultValue, Description) \
137 RegisterFlag(parser, #Name, Description, &f->Name);
138 #include "msan_flags.inc"
139 #undef MSAN_FLAG
140
141 FlagHandlerKeepGoing *fh_keep_going = new (GetGlobalLowLevelAllocator())
142 FlagHandlerKeepGoing(&f->halt_on_error);
143 parser->RegisterHandler("keep_going", fh_keep_going,
144 "deprecated, use halt_on_error");
145 }
146
InitializeFlags()147 static void InitializeFlags() {
148 SetCommonFlagsDefaults();
149 {
150 CommonFlags cf;
151 cf.CopyFrom(*common_flags());
152 cf.external_symbolizer_path = GetEnv("MSAN_SYMBOLIZER_PATH");
153 cf.malloc_context_size = 20;
154 cf.handle_ioctl = true;
155 // FIXME: test and enable.
156 cf.check_printf = false;
157 cf.intercept_tls_get_addr = true;
158 OverrideCommonFlags(cf);
159 }
160
161 Flags *f = flags();
162 f->SetDefaults();
163
164 FlagParser parser;
165 RegisterMsanFlags(&parser, f);
166 RegisterCommonFlags(&parser);
167
168 #if MSAN_CONTAINS_UBSAN
169 __ubsan::Flags *uf = __ubsan::flags();
170 uf->SetDefaults();
171
172 FlagParser ubsan_parser;
173 __ubsan::RegisterUbsanFlags(&ubsan_parser, uf);
174 RegisterCommonFlags(&ubsan_parser);
175 #endif
176
177 // Override from user-specified string.
178 parser.ParseString(__msan_default_options());
179 #if MSAN_CONTAINS_UBSAN
180 const char *ubsan_default_options = __ubsan_default_options();
181 ubsan_parser.ParseString(ubsan_default_options);
182 #endif
183
184 parser.ParseStringFromEnv("MSAN_OPTIONS");
185 #if MSAN_CONTAINS_UBSAN
186 ubsan_parser.ParseStringFromEnv("UBSAN_OPTIONS");
187 #endif
188
189 InitializeCommonFlags();
190
191 if (Verbosity()) ReportUnrecognizedFlags();
192
193 if (common_flags()->help) parser.PrintFlagDescriptions();
194
195 // Check if deprecated exit_code MSan flag is set.
196 if (f->exit_code != -1) {
197 if (Verbosity())
198 Printf("MSAN_OPTIONS=exit_code is deprecated! "
199 "Please use MSAN_OPTIONS=exitcode instead.\n");
200 CommonFlags cf;
201 cf.CopyFrom(*common_flags());
202 cf.exitcode = f->exit_code;
203 OverrideCommonFlags(cf);
204 }
205
206 // Check flag values:
207 if (f->origin_history_size < 0 ||
208 f->origin_history_size > Origin::kMaxDepth) {
209 Printf(
210 "Origin history size invalid: %d. Must be 0 (unlimited) or in [1, %d] "
211 "range.\n",
212 f->origin_history_size, Origin::kMaxDepth);
213 Die();
214 }
215 // Limiting to kStackDepotMaxUseCount / 2 to avoid overflow in
216 // StackDepotHandle::inc_use_count_unsafe.
217 if (f->origin_history_per_stack_limit < 0 ||
218 f->origin_history_per_stack_limit > kStackDepotMaxUseCount / 2) {
219 Printf(
220 "Origin per-stack limit invalid: %d. Must be 0 (unlimited) or in [1, "
221 "%d] range.\n",
222 f->origin_history_per_stack_limit, kStackDepotMaxUseCount / 2);
223 Die();
224 }
225 if (f->store_context_size < 1) f->store_context_size = 1;
226 }
227
PrintWarningWithOrigin(uptr pc,uptr bp,u32 origin)228 void PrintWarningWithOrigin(uptr pc, uptr bp, u32 origin) {
229 if (msan_expect_umr) {
230 // Printf("Expected UMR\n");
231 __msan_origin_tls = origin;
232 msan_expected_umr_found = 1;
233 return;
234 }
235
236 ++msan_report_count;
237
238 GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
239
240 u32 report_origin =
241 (__msan_get_track_origins() && Origin::isValidId(origin)) ? origin : 0;
242 ReportUMR(&stack, report_origin);
243
244 if (__msan_get_track_origins() && !Origin::isValidId(origin)) {
245 Printf(
246 " ORIGIN: invalid (%x). Might be a bug in MemorySanitizer origin "
247 "tracking.\n This could still be a bug in your code, too!\n",
248 origin);
249 }
250 }
251
UnpoisonParam(uptr n)252 void UnpoisonParam(uptr n) {
253 internal_memset(__msan_param_tls, 0, n * sizeof(*__msan_param_tls));
254 }
255
256 // Backup MSan runtime TLS state.
257 // Implementation must be async-signal-safe.
258 // Instances of this class may live on the signal handler stack, and data size
259 // may be an issue.
Backup()260 void ScopedThreadLocalStateBackup::Backup() {
261 va_arg_overflow_size_tls = __msan_va_arg_overflow_size_tls;
262 }
263
Restore()264 void ScopedThreadLocalStateBackup::Restore() {
265 // A lame implementation that only keeps essential state and resets the rest.
266 __msan_va_arg_overflow_size_tls = va_arg_overflow_size_tls;
267
268 internal_memset(__msan_param_tls, 0, sizeof(__msan_param_tls));
269 internal_memset(__msan_retval_tls, 0, sizeof(__msan_retval_tls));
270 internal_memset(__msan_va_arg_tls, 0, sizeof(__msan_va_arg_tls));
271 internal_memset(__msan_va_arg_origin_tls, 0,
272 sizeof(__msan_va_arg_origin_tls));
273
274 if (__msan_get_track_origins()) {
275 internal_memset(&__msan_retval_origin_tls, 0,
276 sizeof(__msan_retval_origin_tls));
277 internal_memset(__msan_param_origin_tls, 0,
278 sizeof(__msan_param_origin_tls));
279 }
280 }
281
UnpoisonThreadLocalState()282 void UnpoisonThreadLocalState() {
283 }
284
GetStackOriginDescr(u32 id,uptr * pc)285 const char *GetStackOriginDescr(u32 id, uptr *pc) {
286 CHECK_LT(id, kNumStackOriginDescrs);
287 if (pc) *pc = StackOriginPC[id];
288 return StackOriginDescr[id];
289 }
290
ChainOrigin(u32 id,StackTrace * stack)291 u32 ChainOrigin(u32 id, StackTrace *stack) {
292 MsanThread *t = GetCurrentThread();
293 if (t && t->InSignalHandler())
294 return id;
295
296 Origin o = Origin::FromRawId(id);
297 stack->tag = StackTrace::TAG_UNKNOWN;
298 Origin chained = Origin::CreateChainedOrigin(o, stack);
299 return chained.raw_id();
300 }
301
302 // Current implementation separates the 'id_ptr' from the 'descr' and makes
303 // 'descr' constant.
304 // Previous implementation 'descr' is created at compile time and contains
305 // '----' in the beginning. When we see descr for the first time we replace
306 // '----' with a uniq id and set the origin to (id | (31-th bit)).
SetAllocaOrigin(void * a,uptr size,u32 * id_ptr,char * descr,uptr pc)307 static inline void SetAllocaOrigin(void *a, uptr size, u32 *id_ptr, char *descr,
308 uptr pc) {
309 static const u32 dash = '-';
310 static const u32 first_timer =
311 dash + (dash << 8) + (dash << 16) + (dash << 24);
312 u32 id = *id_ptr;
313 if (id == 0 || id == first_timer) {
314 u32 idx = atomic_fetch_add(&NumStackOriginDescrs, 1, memory_order_relaxed);
315 CHECK_LT(idx, kNumStackOriginDescrs);
316 StackOriginDescr[idx] = descr;
317 StackOriginPC[idx] = pc;
318 id = Origin::CreateStackOrigin(idx).raw_id();
319 *id_ptr = id;
320 }
321 __msan_set_origin(a, size, id);
322 }
323
324 } // namespace __msan
325
UnwindImpl(uptr pc,uptr bp,void * context,bool request_fast,u32 max_depth)326 void __sanitizer::BufferedStackTrace::UnwindImpl(
327 uptr pc, uptr bp, void *context, bool request_fast, u32 max_depth) {
328 using namespace __msan;
329 MsanThread *t = GetCurrentThread();
330 if (!t || !StackTrace::WillUseFastUnwind(request_fast)) {
331 // Block reports from our interceptors during _Unwind_Backtrace.
332 UnwinderScope sym_scope;
333 return Unwind(max_depth, pc, bp, context, t ? t->stack_top() : 0,
334 t ? t->stack_bottom() : 0, false);
335 }
336 if (StackTrace::WillUseFastUnwind(request_fast))
337 Unwind(max_depth, pc, bp, nullptr, t->stack_top(), t->stack_bottom(), true);
338 else
339 Unwind(max_depth, pc, 0, context, 0, 0, false);
340 }
341
342 // Interface.
343
344 using namespace __msan;
345
346 #define MSAN_MAYBE_WARNING(type, size) \
347 void __msan_maybe_warning_##size(type s, u32 o) { \
348 GET_CALLER_PC_BP; \
349 if (UNLIKELY(s)) { \
350 PrintWarningWithOrigin(pc, bp, o); \
351 if (__msan::flags()->halt_on_error) { \
352 Printf("Exiting\n"); \
353 Die(); \
354 } \
355 } \
356 }
357
358 MSAN_MAYBE_WARNING(u8, 1)
359 MSAN_MAYBE_WARNING(u16, 2)
360 MSAN_MAYBE_WARNING(u32, 4)
361 MSAN_MAYBE_WARNING(u64, 8)
362
363 #define MSAN_MAYBE_STORE_ORIGIN(type, size) \
364 void __msan_maybe_store_origin_##size(type s, void *p, u32 o) { \
365 if (UNLIKELY(s)) { \
366 if (__msan_get_track_origins() > 1) { \
367 GET_CALLER_PC_BP; \
368 GET_STORE_STACK_TRACE_PC_BP(pc, bp); \
369 o = ChainOrigin(o, &stack); \
370 } \
371 *(u32 *)MEM_TO_ORIGIN((uptr)p & ~3UL) = o; \
372 } \
373 }
374
375 MSAN_MAYBE_STORE_ORIGIN(u8, 1)
376 MSAN_MAYBE_STORE_ORIGIN(u16, 2)
377 MSAN_MAYBE_STORE_ORIGIN(u32, 4)
378 MSAN_MAYBE_STORE_ORIGIN(u64, 8)
379
__msan_warning()380 void __msan_warning() {
381 GET_CALLER_PC_BP;
382 PrintWarningWithOrigin(pc, bp, 0);
383 if (__msan::flags()->halt_on_error) {
384 if (__msan::flags()->print_stats)
385 ReportStats();
386 Printf("Exiting\n");
387 Die();
388 }
389 }
390
__msan_warning_noreturn()391 void __msan_warning_noreturn() {
392 GET_CALLER_PC_BP;
393 PrintWarningWithOrigin(pc, bp, 0);
394 if (__msan::flags()->print_stats)
395 ReportStats();
396 Printf("Exiting\n");
397 Die();
398 }
399
__msan_warning_with_origin(u32 origin)400 void __msan_warning_with_origin(u32 origin) {
401 GET_CALLER_PC_BP;
402 PrintWarningWithOrigin(pc, bp, origin);
403 if (__msan::flags()->halt_on_error) {
404 if (__msan::flags()->print_stats)
405 ReportStats();
406 Printf("Exiting\n");
407 Die();
408 }
409 }
410
__msan_warning_with_origin_noreturn(u32 origin)411 void __msan_warning_with_origin_noreturn(u32 origin) {
412 GET_CALLER_PC_BP;
413 PrintWarningWithOrigin(pc, bp, origin);
414 if (__msan::flags()->print_stats)
415 ReportStats();
416 Printf("Exiting\n");
417 Die();
418 }
419
OnStackUnwind(const SignalContext & sig,const void *,BufferedStackTrace * stack)420 static void OnStackUnwind(const SignalContext &sig, const void *,
421 BufferedStackTrace *stack) {
422 stack->Unwind(StackTrace::GetNextInstructionPc(sig.pc), sig.bp, sig.context,
423 common_flags()->fast_unwind_on_fatal);
424 }
425
MsanOnDeadlySignal(int signo,void * siginfo,void * context)426 static void MsanOnDeadlySignal(int signo, void *siginfo, void *context) {
427 HandleDeadlySignal(siginfo, context, GetTid(), &OnStackUnwind, nullptr);
428 }
429
CheckUnwind()430 static void CheckUnwind() {
431 GET_FATAL_STACK_TRACE_PC_BP(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME());
432 stack.Print();
433 }
434
__msan_init()435 void __msan_init() {
436 CHECK(!msan_init_is_running);
437 if (msan_inited) return;
438 msan_init_is_running = 1;
439 SanitizerToolName = "MemorySanitizer";
440
441 AvoidCVE_2016_2143();
442
443 CacheBinaryName();
444 InitializeFlags();
445
446 // Install tool-specific callbacks in sanitizer_common.
447 SetCheckUnwindCallback(CheckUnwind);
448
449 __sanitizer_set_report_path(common_flags()->log_path);
450
451 InitializeInterceptors();
452 InstallAtForkHandler();
453 CheckASLR();
454 InitTlsSize();
455 InstallDeadlySignalHandlers(MsanOnDeadlySignal);
456 InstallAtExitHandler(); // Needs __cxa_atexit interceptor.
457
458 DisableCoreDumperIfNecessary();
459 if (StackSizeIsUnlimited()) {
460 VPrintf(1, "Unlimited stack, doing reexec\n");
461 // A reasonably large stack size. It is bigger than the usual 8Mb, because,
462 // well, the program could have been run with unlimited stack for a reason.
463 SetStackSizeLimitInBytes(32 * 1024 * 1024);
464 ReExec();
465 }
466
467 __msan_clear_on_return();
468 if (__msan_get_track_origins())
469 VPrintf(1, "msan_track_origins\n");
470 if (!InitShadowWithReExec(__msan_get_track_origins())) {
471 Printf("FATAL: MemorySanitizer can not mmap the shadow memory.\n");
472 Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n");
473 Printf("FATAL: Disabling ASLR is known to cause this error.\n");
474 Printf("FATAL: If running under GDB, try "
475 "'set disable-randomization off'.\n");
476 DumpProcessMap();
477 Die();
478 }
479
480 Symbolizer::GetOrInit()->AddHooks(EnterSymbolizerOrUnwider,
481 ExitSymbolizerOrUnwider);
482
483 InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
484
485 MsanTSDInit(MsanTSDDtor);
486
487 MsanAllocatorInit();
488
489 MsanThread *main_thread = MsanThread::Create(nullptr, nullptr);
490 SetCurrentThread(main_thread);
491 main_thread->Init();
492
493 #if MSAN_CONTAINS_UBSAN
494 __ubsan::InitAsPlugin();
495 #endif
496
497 VPrintf(1, "MemorySanitizer init done\n");
498
499 msan_init_is_running = 0;
500 msan_inited = 1;
501 }
502
__msan_set_keep_going(int keep_going)503 void __msan_set_keep_going(int keep_going) {
504 flags()->halt_on_error = !keep_going;
505 }
506
__msan_set_expect_umr(int expect_umr)507 void __msan_set_expect_umr(int expect_umr) {
508 if (expect_umr) {
509 msan_expected_umr_found = 0;
510 } else if (!msan_expected_umr_found) {
511 GET_CALLER_PC_BP;
512 GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
513 ReportExpectedUMRNotFound(&stack);
514 Die();
515 }
516 msan_expect_umr = expect_umr;
517 }
518
__msan_print_shadow(const void * x,uptr size)519 void __msan_print_shadow(const void *x, uptr size) {
520 if (!MEM_IS_APP(x)) {
521 Printf("Not a valid application address: %p\n", x);
522 return;
523 }
524
525 DescribeMemoryRange(x, size);
526 }
527
__msan_dump_shadow(const void * x,uptr size)528 void __msan_dump_shadow(const void *x, uptr size) {
529 if (!MEM_IS_APP(x)) {
530 Printf("Not a valid application address: %p\n", x);
531 return;
532 }
533
534 unsigned char *s = (unsigned char*)MEM_TO_SHADOW(x);
535 Printf("%p[%p] ", (void *)s, x);
536 for (uptr i = 0; i < size; i++)
537 Printf("%x%x ", s[i] >> 4, s[i] & 0xf);
538 Printf("\n");
539 }
540
__msan_test_shadow(const void * x,uptr size)541 sptr __msan_test_shadow(const void *x, uptr size) {
542 if (!MEM_IS_APP(x)) return -1;
543 unsigned char *s = (unsigned char *)MEM_TO_SHADOW((uptr)x);
544 if (__sanitizer::mem_is_zero((const char *)s, size))
545 return -1;
546 // Slow path: loop through again to find the location.
547 for (uptr i = 0; i < size; ++i)
548 if (s[i])
549 return i;
550 return -1;
551 }
552
__msan_check_mem_is_initialized(const void * x,uptr size)553 void __msan_check_mem_is_initialized(const void *x, uptr size) {
554 if (!__msan::flags()->report_umrs) return;
555 sptr offset = __msan_test_shadow(x, size);
556 if (offset < 0)
557 return;
558
559 GET_CALLER_PC_BP;
560 ReportUMRInsideAddressRange(__func__, x, size, offset);
561 __msan::PrintWarningWithOrigin(pc, bp,
562 __msan_get_origin(((const char *)x) + offset));
563 if (__msan::flags()->halt_on_error) {
564 Printf("Exiting\n");
565 Die();
566 }
567 }
568
__msan_set_poison_in_malloc(int do_poison)569 int __msan_set_poison_in_malloc(int do_poison) {
570 int old = flags()->poison_in_malloc;
571 flags()->poison_in_malloc = do_poison;
572 return old;
573 }
574
__msan_has_dynamic_component()575 int __msan_has_dynamic_component() { return false; }
576
577 NOINLINE
__msan_clear_on_return()578 void __msan_clear_on_return() {
579 __msan_param_tls[0] = 0;
580 }
581
__msan_partial_poison(const void * data,void * shadow,uptr size)582 void __msan_partial_poison(const void* data, void* shadow, uptr size) {
583 internal_memcpy((void*)MEM_TO_SHADOW((uptr)data), shadow, size);
584 }
585
__msan_load_unpoisoned(const void * src,uptr size,void * dst)586 void __msan_load_unpoisoned(const void *src, uptr size, void *dst) {
587 internal_memcpy(dst, src, size);
588 __msan_unpoison(dst, size);
589 }
590
__msan_set_origin(const void * a,uptr size,u32 origin)591 void __msan_set_origin(const void *a, uptr size, u32 origin) {
592 if (__msan_get_track_origins()) SetOrigin(a, size, origin);
593 }
594
__msan_set_alloca_origin(void * a,uptr size,char * descr)595 void __msan_set_alloca_origin(void *a, uptr size, char *descr) {
596 SetAllocaOrigin(a, size, reinterpret_cast<u32 *>(descr), descr + 4,
597 GET_CALLER_PC());
598 }
599
__msan_set_alloca_origin4(void * a,uptr size,char * descr,uptr pc)600 void __msan_set_alloca_origin4(void *a, uptr size, char *descr, uptr pc) {
601 // Intentionally ignore pc and use return address. This function is here for
602 // compatibility, in case program is linked with library instrumented by
603 // older clang.
604 SetAllocaOrigin(a, size, reinterpret_cast<u32 *>(descr), descr + 4,
605 GET_CALLER_PC());
606 }
607
__msan_set_alloca_origin_with_descr(void * a,uptr size,u32 * id_ptr,char * descr)608 void __msan_set_alloca_origin_with_descr(void *a, uptr size, u32 *id_ptr,
609 char *descr) {
610 SetAllocaOrigin(a, size, id_ptr, descr, GET_CALLER_PC());
611 }
612
__msan_set_alloca_origin_no_descr(void * a,uptr size,u32 * id_ptr)613 void __msan_set_alloca_origin_no_descr(void *a, uptr size, u32 *id_ptr) {
614 SetAllocaOrigin(a, size, id_ptr, nullptr, GET_CALLER_PC());
615 }
616
__msan_chain_origin(u32 id)617 u32 __msan_chain_origin(u32 id) {
618 GET_CALLER_PC_BP;
619 GET_STORE_STACK_TRACE_PC_BP(pc, bp);
620 return ChainOrigin(id, &stack);
621 }
622
__msan_get_origin(const void * a)623 u32 __msan_get_origin(const void *a) {
624 if (!__msan_get_track_origins()) return 0;
625 uptr x = (uptr)a;
626 uptr aligned = x & ~3ULL;
627 uptr origin_ptr = MEM_TO_ORIGIN(aligned);
628 return *(u32*)origin_ptr;
629 }
630
__msan_origin_is_descendant_or_same(u32 this_id,u32 prev_id)631 int __msan_origin_is_descendant_or_same(u32 this_id, u32 prev_id) {
632 Origin o = Origin::FromRawId(this_id);
633 while (o.raw_id() != prev_id && o.isChainedOrigin())
634 o = o.getNextChainedOrigin(nullptr);
635 return o.raw_id() == prev_id;
636 }
637
__msan_get_umr_origin()638 u32 __msan_get_umr_origin() {
639 return __msan_origin_tls;
640 }
641
__sanitizer_unaligned_load16(const uu16 * p)642 u16 __sanitizer_unaligned_load16(const uu16 *p) {
643 internal_memcpy(&__msan_retval_tls[0], (void *)MEM_TO_SHADOW((uptr)p),
644 sizeof(uu16));
645 if (__msan_get_track_origins())
646 __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
647 return *p;
648 }
__sanitizer_unaligned_load32(const uu32 * p)649 u32 __sanitizer_unaligned_load32(const uu32 *p) {
650 internal_memcpy(&__msan_retval_tls[0], (void *)MEM_TO_SHADOW((uptr)p),
651 sizeof(uu32));
652 if (__msan_get_track_origins())
653 __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
654 return *p;
655 }
__sanitizer_unaligned_load64(const uu64 * p)656 u64 __sanitizer_unaligned_load64(const uu64 *p) {
657 internal_memcpy(&__msan_retval_tls[0], (void *)MEM_TO_SHADOW((uptr)p),
658 sizeof(uu64));
659 if (__msan_get_track_origins())
660 __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
661 return *p;
662 }
__sanitizer_unaligned_store16(uu16 * p,u16 x)663 void __sanitizer_unaligned_store16(uu16 *p, u16 x) {
664 static_assert(sizeof(uu16) == sizeof(u16), "incompatible types");
665 u16 s;
666 internal_memcpy(&s, &__msan_param_tls[1], sizeof(uu16));
667 internal_memcpy((void *)MEM_TO_SHADOW((uptr)p), &s, sizeof(uu16));
668 if (s && __msan_get_track_origins())
669 if (uu32 o = __msan_param_origin_tls[2])
670 SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
671 *p = x;
672 }
__sanitizer_unaligned_store32(uu32 * p,u32 x)673 void __sanitizer_unaligned_store32(uu32 *p, u32 x) {
674 static_assert(sizeof(uu32) == sizeof(u32), "incompatible types");
675 u32 s;
676 internal_memcpy(&s, &__msan_param_tls[1], sizeof(uu32));
677 internal_memcpy((void *)MEM_TO_SHADOW((uptr)p), &s, sizeof(uu32));
678 if (s && __msan_get_track_origins())
679 if (uu32 o = __msan_param_origin_tls[2])
680 SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
681 *p = x;
682 }
__sanitizer_unaligned_store64(uu64 * p,u64 x)683 void __sanitizer_unaligned_store64(uu64 *p, u64 x) {
684 u64 s = __msan_param_tls[1];
685 *(uu64 *)MEM_TO_SHADOW((uptr)p) = s;
686 if (s && __msan_get_track_origins())
687 if (uu32 o = __msan_param_origin_tls[2])
688 SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
689 *p = x;
690 }
691
__msan_set_death_callback(void (* callback)(void))692 void __msan_set_death_callback(void (*callback)(void)) {
693 SetUserDieCallback(callback);
694 }
695
__msan_start_switch_fiber(const void * bottom,uptr size)696 void __msan_start_switch_fiber(const void *bottom, uptr size) {
697 MsanThread *t = GetCurrentThread();
698 if (!t) {
699 VReport(1, "__msan_start_switch_fiber called from unknown thread\n");
700 return;
701 }
702 t->StartSwitchFiber((uptr)bottom, size);
703 }
704
__msan_finish_switch_fiber(const void ** bottom_old,uptr * size_old)705 void __msan_finish_switch_fiber(const void **bottom_old, uptr *size_old) {
706 MsanThread *t = GetCurrentThread();
707 if (!t) {
708 VReport(1, "__msan_finish_switch_fiber called from unknown thread\n");
709 return;
710 }
711 t->FinishSwitchFiber((uptr *)bottom_old, (uptr *)size_old);
712
713 internal_memset(__msan_param_tls, 0, sizeof(__msan_param_tls));
714 internal_memset(__msan_retval_tls, 0, sizeof(__msan_retval_tls));
715 internal_memset(__msan_va_arg_tls, 0, sizeof(__msan_va_arg_tls));
716
717 if (__msan_get_track_origins()) {
718 internal_memset(__msan_param_origin_tls, 0,
719 sizeof(__msan_param_origin_tls));
720 internal_memset(&__msan_retval_origin_tls, 0,
721 sizeof(__msan_retval_origin_tls));
722 internal_memset(__msan_va_arg_origin_tls, 0,
723 sizeof(__msan_va_arg_origin_tls));
724 }
725 }
726
SANITIZER_INTERFACE_WEAK_DEF(const char *,__msan_default_options,void)727 SANITIZER_INTERFACE_WEAK_DEF(const char *, __msan_default_options, void) {
728 return "";
729 }
730
731 extern "C" {
732 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_print_stack_trace()733 void __sanitizer_print_stack_trace() {
734 GET_FATAL_STACK_TRACE_PC_BP(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME());
735 stack.Print();
736 }
737 } // extern "C"
738