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 #include "msan_chained_origin_depot.h"
16 #include "msan_origin.h"
17 #include "msan_report.h"
18 #include "msan_thread.h"
19 #include "msan_poisoning.h"
20 #include "sanitizer_common/sanitizer_atomic.h"
21 #include "sanitizer_common/sanitizer_common.h"
22 #include "sanitizer_common/sanitizer_flags.h"
23 #include "sanitizer_common/sanitizer_flag_parser.h"
24 #include "sanitizer_common/sanitizer_libc.h"
25 #include "sanitizer_common/sanitizer_procmaps.h"
26 #include "sanitizer_common/sanitizer_stacktrace.h"
27 #include "sanitizer_common/sanitizer_symbolizer.h"
28 #include "sanitizer_common/sanitizer_stackdepot.h"
29 #include "ubsan/ubsan_flags.h"
30 #include "ubsan/ubsan_init.h"
31
32 // ACHTUNG! No system header includes in this file.
33
34 using namespace __sanitizer;
35
36 // Globals.
37 static THREADLOCAL int msan_expect_umr = 0;
38 static THREADLOCAL int msan_expected_umr_found = 0;
39
40 // Function argument shadow. Each argument starts at the next available 8-byte
41 // aligned address.
42 SANITIZER_INTERFACE_ATTRIBUTE
43 THREADLOCAL u64 __msan_param_tls[kMsanParamTlsSize / sizeof(u64)];
44
45 // Function argument origin. Each argument starts at the same offset as the
46 // corresponding shadow in (__msan_param_tls). Slightly weird, but changing this
47 // would break compatibility with older prebuilt binaries.
48 SANITIZER_INTERFACE_ATTRIBUTE
49 THREADLOCAL u32 __msan_param_origin_tls[kMsanParamTlsSize / sizeof(u32)];
50
51 SANITIZER_INTERFACE_ATTRIBUTE
52 THREADLOCAL u64 __msan_retval_tls[kMsanRetvalTlsSize / sizeof(u64)];
53
54 SANITIZER_INTERFACE_ATTRIBUTE
55 THREADLOCAL u32 __msan_retval_origin_tls;
56
57 SANITIZER_INTERFACE_ATTRIBUTE
58 ALIGNED(16) THREADLOCAL u64 __msan_va_arg_tls[kMsanParamTlsSize / sizeof(u64)];
59
60 SANITIZER_INTERFACE_ATTRIBUTE
61 ALIGNED(16)
62 THREADLOCAL u32 __msan_va_arg_origin_tls[kMsanParamTlsSize / sizeof(u32)];
63
64 SANITIZER_INTERFACE_ATTRIBUTE
65 THREADLOCAL u64 __msan_va_arg_overflow_size_tls;
66
67 SANITIZER_INTERFACE_ATTRIBUTE
68 THREADLOCAL u32 __msan_origin_tls;
69
70 static THREADLOCAL int is_in_symbolizer;
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
EnterSymbolizer()82 void EnterSymbolizer() { ++is_in_symbolizer; }
ExitSymbolizer()83 void ExitSymbolizer() { --is_in_symbolizer; }
IsInSymbolizer()84 bool IsInSymbolizer() { return is_in_symbolizer; }
85
86 static Flags msan_flags;
87
flags()88 Flags *flags() {
89 return &msan_flags;
90 }
91
92 int msan_inited = 0;
93 bool msan_init_is_running;
94
95 int msan_report_count = 0;
96
97 // Array of stack origins.
98 // FIXME: make it resizable.
99 static const uptr kNumStackOriginDescrs = 1024 * 1024;
100 static const char *StackOriginDescr[kNumStackOriginDescrs];
101 static uptr StackOriginPC[kNumStackOriginDescrs];
102 static atomic_uint32_t NumStackOriginDescrs;
103
SetDefaults()104 void Flags::SetDefaults() {
105 #define MSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
106 #include "msan_flags.inc"
107 #undef MSAN_FLAG
108 }
109
110 // keep_going is an old name for halt_on_error,
111 // and it has inverse meaning.
112 class FlagHandlerKeepGoing final : public FlagHandlerBase {
113 bool *halt_on_error_;
114
115 public:
FlagHandlerKeepGoing(bool * halt_on_error)116 explicit FlagHandlerKeepGoing(bool *halt_on_error)
117 : halt_on_error_(halt_on_error) {}
Parse(const char * value)118 bool Parse(const char *value) final {
119 bool tmp;
120 FlagHandler<bool> h(&tmp);
121 if (!h.Parse(value)) return false;
122 *halt_on_error_ = !tmp;
123 return true;
124 }
Format(char * buffer,uptr size)125 bool Format(char *buffer, uptr size) final {
126 const char *keep_going_str = (*halt_on_error_) ? "false" : "true";
127 return FormatString(buffer, size, keep_going_str);
128 }
129 };
130
RegisterMsanFlags(FlagParser * parser,Flags * f)131 static void RegisterMsanFlags(FlagParser *parser, Flags *f) {
132 #define MSAN_FLAG(Type, Name, DefaultValue, Description) \
133 RegisterFlag(parser, #Name, Description, &f->Name);
134 #include "msan_flags.inc"
135 #undef MSAN_FLAG
136
137 FlagHandlerKeepGoing *fh_keep_going =
138 new (FlagParser::Alloc) FlagHandlerKeepGoing(&f->halt_on_error);
139 parser->RegisterHandler("keep_going", fh_keep_going,
140 "deprecated, use halt_on_error");
141 }
142
InitializeFlags()143 static void InitializeFlags() {
144 SetCommonFlagsDefaults();
145 {
146 CommonFlags cf;
147 cf.CopyFrom(*common_flags());
148 cf.external_symbolizer_path = GetEnv("MSAN_SYMBOLIZER_PATH");
149 cf.malloc_context_size = 20;
150 cf.handle_ioctl = true;
151 // FIXME: test and enable.
152 cf.check_printf = false;
153 cf.intercept_tls_get_addr = true;
154 cf.exitcode = 77;
155 OverrideCommonFlags(cf);
156 }
157
158 Flags *f = flags();
159 f->SetDefaults();
160
161 FlagParser parser;
162 RegisterMsanFlags(&parser, f);
163 RegisterCommonFlags(&parser);
164
165 #if MSAN_CONTAINS_UBSAN
166 __ubsan::Flags *uf = __ubsan::flags();
167 uf->SetDefaults();
168
169 FlagParser ubsan_parser;
170 __ubsan::RegisterUbsanFlags(&ubsan_parser, uf);
171 RegisterCommonFlags(&ubsan_parser);
172 #endif
173
174 // Override from user-specified string.
175 parser.ParseString(__msan_default_options());
176 #if MSAN_CONTAINS_UBSAN
177 const char *ubsan_default_options = __ubsan_default_options();
178 ubsan_parser.ParseString(ubsan_default_options);
179 #endif
180
181 parser.ParseStringFromEnv("MSAN_OPTIONS");
182 #if MSAN_CONTAINS_UBSAN
183 ubsan_parser.ParseStringFromEnv("UBSAN_OPTIONS");
184 #endif
185
186 InitializeCommonFlags();
187
188 if (Verbosity()) ReportUnrecognizedFlags();
189
190 if (common_flags()->help) parser.PrintFlagDescriptions();
191
192 // Check if deprecated exit_code MSan flag is set.
193 if (f->exit_code != -1) {
194 if (Verbosity())
195 Printf("MSAN_OPTIONS=exit_code is deprecated! "
196 "Please use MSAN_OPTIONS=exitcode instead.\n");
197 CommonFlags cf;
198 cf.CopyFrom(*common_flags());
199 cf.exitcode = f->exit_code;
200 OverrideCommonFlags(cf);
201 }
202
203 // Check flag values:
204 if (f->origin_history_size < 0 ||
205 f->origin_history_size > Origin::kMaxDepth) {
206 Printf(
207 "Origin history size invalid: %d. Must be 0 (unlimited) or in [1, %d] "
208 "range.\n",
209 f->origin_history_size, Origin::kMaxDepth);
210 Die();
211 }
212 // Limiting to kStackDepotMaxUseCount / 2 to avoid overflow in
213 // StackDepotHandle::inc_use_count_unsafe.
214 if (f->origin_history_per_stack_limit < 0 ||
215 f->origin_history_per_stack_limit > kStackDepotMaxUseCount / 2) {
216 Printf(
217 "Origin per-stack limit invalid: %d. Must be 0 (unlimited) or in [1, "
218 "%d] range.\n",
219 f->origin_history_per_stack_limit, kStackDepotMaxUseCount / 2);
220 Die();
221 }
222 if (f->store_context_size < 1) f->store_context_size = 1;
223 }
224
PrintWarning(uptr pc,uptr bp)225 void PrintWarning(uptr pc, uptr bp) {
226 PrintWarningWithOrigin(pc, bp, __msan_origin_tls);
227 }
228
PrintWarningWithOrigin(uptr pc,uptr bp,u32 origin)229 void PrintWarningWithOrigin(uptr pc, uptr bp, u32 origin) {
230 if (msan_expect_umr) {
231 // Printf("Expected UMR\n");
232 __msan_origin_tls = origin;
233 msan_expected_umr_found = 1;
234 return;
235 }
236
237 ++msan_report_count;
238
239 GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
240
241 u32 report_origin =
242 (__msan_get_track_origins() && Origin::isValidId(origin)) ? origin : 0;
243 ReportUMR(&stack, report_origin);
244
245 if (__msan_get_track_origins() && !Origin::isValidId(origin)) {
246 Printf(
247 " ORIGIN: invalid (%x). Might be a bug in MemorySanitizer origin "
248 "tracking.\n This could still be a bug in your code, too!\n",
249 origin);
250 }
251 }
252
UnpoisonParam(uptr n)253 void UnpoisonParam(uptr n) {
254 internal_memset(__msan_param_tls, 0, n * sizeof(*__msan_param_tls));
255 }
256
257 // Backup MSan runtime TLS state.
258 // Implementation must be async-signal-safe.
259 // Instances of this class may live on the signal handler stack, and data size
260 // may be an issue.
Backup()261 void ScopedThreadLocalStateBackup::Backup() {
262 va_arg_overflow_size_tls = __msan_va_arg_overflow_size_tls;
263 }
264
Restore()265 void ScopedThreadLocalStateBackup::Restore() {
266 // A lame implementation that only keeps essential state and resets the rest.
267 __msan_va_arg_overflow_size_tls = va_arg_overflow_size_tls;
268
269 internal_memset(__msan_param_tls, 0, sizeof(__msan_param_tls));
270 internal_memset(__msan_retval_tls, 0, sizeof(__msan_retval_tls));
271 internal_memset(__msan_va_arg_tls, 0, sizeof(__msan_va_arg_tls));
272 internal_memset(__msan_va_arg_origin_tls, 0,
273 sizeof(__msan_va_arg_origin_tls));
274
275 if (__msan_get_track_origins()) {
276 internal_memset(&__msan_retval_origin_tls, 0,
277 sizeof(__msan_retval_origin_tls));
278 internal_memset(__msan_param_origin_tls, 0,
279 sizeof(__msan_param_origin_tls));
280 }
281 }
282
UnpoisonThreadLocalState()283 void UnpoisonThreadLocalState() {
284 }
285
GetStackOriginDescr(u32 id,uptr * pc)286 const char *GetStackOriginDescr(u32 id, uptr *pc) {
287 CHECK_LT(id, kNumStackOriginDescrs);
288 if (pc) *pc = StackOriginPC[id];
289 return StackOriginDescr[id];
290 }
291
ChainOrigin(u32 id,StackTrace * stack)292 u32 ChainOrigin(u32 id, StackTrace *stack) {
293 MsanThread *t = GetCurrentThread();
294 if (t && t->InSignalHandler())
295 return id;
296
297 Origin o = Origin::FromRawId(id);
298 stack->tag = StackTrace::TAG_UNKNOWN;
299 Origin chained = Origin::CreateChainedOrigin(o, stack);
300 return chained.raw_id();
301 }
302
303 } // namespace __msan
304
UnwindImpl(uptr pc,uptr bp,void * context,bool request_fast,u32 max_depth)305 void __sanitizer::BufferedStackTrace::UnwindImpl(
306 uptr pc, uptr bp, void *context, bool request_fast, u32 max_depth) {
307 using namespace __msan;
308 MsanThread *t = GetCurrentThread();
309 if (!t || !StackTrace::WillUseFastUnwind(request_fast)) {
310 // Block reports from our interceptors during _Unwind_Backtrace.
311 SymbolizerScope sym_scope;
312 return Unwind(max_depth, pc, bp, context, 0, 0, false);
313 }
314 if (StackTrace::WillUseFastUnwind(request_fast))
315 Unwind(max_depth, pc, bp, nullptr, t->stack_top(), t->stack_bottom(), true);
316 else
317 Unwind(max_depth, pc, 0, context, 0, 0, false);
318 }
319
320 // Interface.
321
322 using namespace __msan;
323
324 #define MSAN_MAYBE_WARNING(type, size) \
325 void __msan_maybe_warning_##size(type s, u32 o) { \
326 GET_CALLER_PC_BP_SP; \
327 (void) sp; \
328 if (UNLIKELY(s)) { \
329 PrintWarningWithOrigin(pc, bp, o); \
330 if (__msan::flags()->halt_on_error) { \
331 Printf("Exiting\n"); \
332 Die(); \
333 } \
334 } \
335 }
336
337 MSAN_MAYBE_WARNING(u8, 1)
338 MSAN_MAYBE_WARNING(u16, 2)
339 MSAN_MAYBE_WARNING(u32, 4)
340 MSAN_MAYBE_WARNING(u64, 8)
341
342 #define MSAN_MAYBE_STORE_ORIGIN(type, size) \
343 void __msan_maybe_store_origin_##size(type s, void *p, u32 o) { \
344 if (UNLIKELY(s)) { \
345 if (__msan_get_track_origins() > 1) { \
346 GET_CALLER_PC_BP_SP; \
347 (void) sp; \
348 GET_STORE_STACK_TRACE_PC_BP(pc, bp); \
349 o = ChainOrigin(o, &stack); \
350 } \
351 *(u32 *)MEM_TO_ORIGIN((uptr)p & ~3UL) = o; \
352 } \
353 }
354
355 MSAN_MAYBE_STORE_ORIGIN(u8, 1)
356 MSAN_MAYBE_STORE_ORIGIN(u16, 2)
357 MSAN_MAYBE_STORE_ORIGIN(u32, 4)
358 MSAN_MAYBE_STORE_ORIGIN(u64, 8)
359
__msan_warning()360 void __msan_warning() {
361 GET_CALLER_PC_BP_SP;
362 (void)sp;
363 PrintWarning(pc, bp);
364 if (__msan::flags()->halt_on_error) {
365 if (__msan::flags()->print_stats)
366 ReportStats();
367 Printf("Exiting\n");
368 Die();
369 }
370 }
371
__msan_warning_noreturn()372 void __msan_warning_noreturn() {
373 GET_CALLER_PC_BP_SP;
374 (void)sp;
375 PrintWarning(pc, bp);
376 if (__msan::flags()->print_stats)
377 ReportStats();
378 Printf("Exiting\n");
379 Die();
380 }
381
__msan_warning_with_origin(u32 origin)382 void __msan_warning_with_origin(u32 origin) {
383 GET_CALLER_PC_BP_SP;
384 (void)sp;
385 PrintWarningWithOrigin(pc, bp, origin);
386 if (__msan::flags()->halt_on_error) {
387 if (__msan::flags()->print_stats)
388 ReportStats();
389 Printf("Exiting\n");
390 Die();
391 }
392 }
393
__msan_warning_with_origin_noreturn(u32 origin)394 void __msan_warning_with_origin_noreturn(u32 origin) {
395 GET_CALLER_PC_BP_SP;
396 (void)sp;
397 PrintWarningWithOrigin(pc, bp, origin);
398 if (__msan::flags()->print_stats)
399 ReportStats();
400 Printf("Exiting\n");
401 Die();
402 }
403
OnStackUnwind(const SignalContext & sig,const void *,BufferedStackTrace * stack)404 static void OnStackUnwind(const SignalContext &sig, const void *,
405 BufferedStackTrace *stack) {
406 stack->Unwind(StackTrace::GetNextInstructionPc(sig.pc), sig.bp, sig.context,
407 common_flags()->fast_unwind_on_fatal);
408 }
409
MsanOnDeadlySignal(int signo,void * siginfo,void * context)410 static void MsanOnDeadlySignal(int signo, void *siginfo, void *context) {
411 HandleDeadlySignal(siginfo, context, GetTid(), &OnStackUnwind, nullptr);
412 }
413
MsanCheckFailed(const char * file,int line,const char * cond,u64 v1,u64 v2)414 static void MsanCheckFailed(const char *file, int line, const char *cond,
415 u64 v1, u64 v2) {
416 Report("MemorySanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", file,
417 line, cond, (uptr)v1, (uptr)v2);
418 PRINT_CURRENT_STACK_CHECK();
419 Die();
420 }
421
__msan_init()422 void __msan_init() {
423 CHECK(!msan_init_is_running);
424 if (msan_inited) return;
425 msan_init_is_running = 1;
426 SanitizerToolName = "MemorySanitizer";
427
428 AvoidCVE_2016_2143();
429
430 CacheBinaryName();
431 InitializeFlags();
432
433 // Install tool-specific callbacks in sanitizer_common.
434 SetCheckFailedCallback(MsanCheckFailed);
435
436 __sanitizer_set_report_path(common_flags()->log_path);
437
438 InitializeInterceptors();
439 CheckASLR();
440 InitTlsSize();
441 InstallDeadlySignalHandlers(MsanOnDeadlySignal);
442 InstallAtExitHandler(); // Needs __cxa_atexit interceptor.
443
444 DisableCoreDumperIfNecessary();
445 if (StackSizeIsUnlimited()) {
446 VPrintf(1, "Unlimited stack, doing reexec\n");
447 // A reasonably large stack size. It is bigger than the usual 8Mb, because,
448 // well, the program could have been run with unlimited stack for a reason.
449 SetStackSizeLimitInBytes(32 * 1024 * 1024);
450 ReExec();
451 }
452
453 __msan_clear_on_return();
454 if (__msan_get_track_origins())
455 VPrintf(1, "msan_track_origins\n");
456 if (!InitShadow(__msan_get_track_origins())) {
457 Printf("FATAL: MemorySanitizer can not mmap the shadow memory.\n");
458 Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n");
459 Printf("FATAL: Disabling ASLR is known to cause this error.\n");
460 Printf("FATAL: If running under GDB, try "
461 "'set disable-randomization off'.\n");
462 DumpProcessMap();
463 Die();
464 }
465
466 Symbolizer::GetOrInit()->AddHooks(EnterSymbolizer, ExitSymbolizer);
467
468 InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
469
470 MsanTSDInit(MsanTSDDtor);
471
472 MsanAllocatorInit();
473
474 MsanThread *main_thread = MsanThread::Create(nullptr, nullptr);
475 SetCurrentThread(main_thread);
476 main_thread->ThreadStart();
477
478 #if MSAN_CONTAINS_UBSAN
479 __ubsan::InitAsPlugin();
480 #endif
481
482 VPrintf(1, "MemorySanitizer init done\n");
483
484 msan_init_is_running = 0;
485 msan_inited = 1;
486 }
487
__msan_set_keep_going(int keep_going)488 void __msan_set_keep_going(int keep_going) {
489 flags()->halt_on_error = !keep_going;
490 }
491
__msan_set_expect_umr(int expect_umr)492 void __msan_set_expect_umr(int expect_umr) {
493 if (expect_umr) {
494 msan_expected_umr_found = 0;
495 } else if (!msan_expected_umr_found) {
496 GET_CALLER_PC_BP_SP;
497 (void)sp;
498 GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
499 ReportExpectedUMRNotFound(&stack);
500 Die();
501 }
502 msan_expect_umr = expect_umr;
503 }
504
__msan_print_shadow(const void * x,uptr size)505 void __msan_print_shadow(const void *x, uptr size) {
506 if (!MEM_IS_APP(x)) {
507 Printf("Not a valid application address: %p\n", x);
508 return;
509 }
510
511 DescribeMemoryRange(x, size);
512 }
513
__msan_dump_shadow(const void * x,uptr size)514 void __msan_dump_shadow(const void *x, uptr size) {
515 if (!MEM_IS_APP(x)) {
516 Printf("Not a valid application address: %p\n", x);
517 return;
518 }
519
520 unsigned char *s = (unsigned char*)MEM_TO_SHADOW(x);
521 for (uptr i = 0; i < size; i++)
522 Printf("%x%x ", s[i] >> 4, s[i] & 0xf);
523 Printf("\n");
524 }
525
__msan_test_shadow(const void * x,uptr size)526 sptr __msan_test_shadow(const void *x, uptr size) {
527 if (!MEM_IS_APP(x)) return -1;
528 unsigned char *s = (unsigned char *)MEM_TO_SHADOW((uptr)x);
529 if (__sanitizer::mem_is_zero((const char *)s, size))
530 return -1;
531 // Slow path: loop through again to find the location.
532 for (uptr i = 0; i < size; ++i)
533 if (s[i])
534 return i;
535 return -1;
536 }
537
__msan_check_mem_is_initialized(const void * x,uptr size)538 void __msan_check_mem_is_initialized(const void *x, uptr size) {
539 if (!__msan::flags()->report_umrs) return;
540 sptr offset = __msan_test_shadow(x, size);
541 if (offset < 0)
542 return;
543
544 GET_CALLER_PC_BP_SP;
545 (void)sp;
546 ReportUMRInsideAddressRange(__func__, x, size, offset);
547 __msan::PrintWarningWithOrigin(pc, bp,
548 __msan_get_origin(((const char *)x) + offset));
549 if (__msan::flags()->halt_on_error) {
550 Printf("Exiting\n");
551 Die();
552 }
553 }
554
__msan_set_poison_in_malloc(int do_poison)555 int __msan_set_poison_in_malloc(int do_poison) {
556 int old = flags()->poison_in_malloc;
557 flags()->poison_in_malloc = do_poison;
558 return old;
559 }
560
__msan_has_dynamic_component()561 int __msan_has_dynamic_component() { return false; }
562
563 NOINLINE
__msan_clear_on_return()564 void __msan_clear_on_return() {
565 __msan_param_tls[0] = 0;
566 }
567
__msan_partial_poison(const void * data,void * shadow,uptr size)568 void __msan_partial_poison(const void* data, void* shadow, uptr size) {
569 internal_memcpy((void*)MEM_TO_SHADOW((uptr)data), shadow, size);
570 }
571
__msan_load_unpoisoned(const void * src,uptr size,void * dst)572 void __msan_load_unpoisoned(const void *src, uptr size, void *dst) {
573 internal_memcpy(dst, src, size);
574 __msan_unpoison(dst, size);
575 }
576
__msan_set_origin(const void * a,uptr size,u32 origin)577 void __msan_set_origin(const void *a, uptr size, u32 origin) {
578 if (__msan_get_track_origins()) SetOrigin(a, size, origin);
579 }
580
581 // 'descr' is created at compile time and contains '----' in the beginning.
582 // When we see descr for the first time we replace '----' with a uniq id
583 // and set the origin to (id | (31-th bit)).
__msan_set_alloca_origin(void * a,uptr size,char * descr)584 void __msan_set_alloca_origin(void *a, uptr size, char *descr) {
585 __msan_set_alloca_origin4(a, size, descr, 0);
586 }
587
__msan_set_alloca_origin4(void * a,uptr size,char * descr,uptr pc)588 void __msan_set_alloca_origin4(void *a, uptr size, char *descr, uptr pc) {
589 static const u32 dash = '-';
590 static const u32 first_timer =
591 dash + (dash << 8) + (dash << 16) + (dash << 24);
592 u32 *id_ptr = (u32*)descr;
593 bool print = false; // internal_strstr(descr + 4, "AllocaTOTest") != 0;
594 u32 id = *id_ptr;
595 if (id == first_timer) {
596 u32 idx = atomic_fetch_add(&NumStackOriginDescrs, 1, memory_order_relaxed);
597 CHECK_LT(idx, kNumStackOriginDescrs);
598 StackOriginDescr[idx] = descr + 4;
599 #if SANITIZER_PPC64V1
600 // On PowerPC64 ELFv1, the address of a function actually points to a
601 // three-doubleword data structure with the first field containing
602 // the address of the function's code.
603 if (pc)
604 pc = *reinterpret_cast<uptr*>(pc);
605 #endif
606 StackOriginPC[idx] = pc;
607 id = Origin::CreateStackOrigin(idx).raw_id();
608 *id_ptr = id;
609 if (print)
610 Printf("First time: idx=%d id=%d %s %p \n", idx, id, descr + 4, pc);
611 }
612 if (print)
613 Printf("__msan_set_alloca_origin: descr=%s id=%x\n", descr + 4, id);
614 __msan_set_origin(a, size, id);
615 }
616
__msan_chain_origin(u32 id)617 u32 __msan_chain_origin(u32 id) {
618 GET_CALLER_PC_BP_SP;
619 (void)sp;
620 GET_STORE_STACK_TRACE_PC_BP(pc, bp);
621 return ChainOrigin(id, &stack);
622 }
623
__msan_get_origin(const void * a)624 u32 __msan_get_origin(const void *a) {
625 if (!__msan_get_track_origins()) return 0;
626 uptr x = (uptr)a;
627 uptr aligned = x & ~3ULL;
628 uptr origin_ptr = MEM_TO_ORIGIN(aligned);
629 return *(u32*)origin_ptr;
630 }
631
__msan_origin_is_descendant_or_same(u32 this_id,u32 prev_id)632 int __msan_origin_is_descendant_or_same(u32 this_id, u32 prev_id) {
633 Origin o = Origin::FromRawId(this_id);
634 while (o.raw_id() != prev_id && o.isChainedOrigin())
635 o = o.getNextChainedOrigin(nullptr);
636 return o.raw_id() == prev_id;
637 }
638
__msan_get_umr_origin()639 u32 __msan_get_umr_origin() {
640 return __msan_origin_tls;
641 }
642
__sanitizer_unaligned_load16(const uu16 * p)643 u16 __sanitizer_unaligned_load16(const uu16 *p) {
644 internal_memcpy(&__msan_retval_tls[0], (void *)MEM_TO_SHADOW((uptr)p),
645 sizeof(uu16));
646 if (__msan_get_track_origins())
647 __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
648 return *p;
649 }
__sanitizer_unaligned_load32(const uu32 * p)650 u32 __sanitizer_unaligned_load32(const uu32 *p) {
651 internal_memcpy(&__msan_retval_tls[0], (void *)MEM_TO_SHADOW((uptr)p),
652 sizeof(uu32));
653 if (__msan_get_track_origins())
654 __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
655 return *p;
656 }
__sanitizer_unaligned_load64(const uu64 * p)657 u64 __sanitizer_unaligned_load64(const uu64 *p) {
658 internal_memcpy(&__msan_retval_tls[0], (void *)MEM_TO_SHADOW((uptr)p),
659 sizeof(uu64));
660 if (__msan_get_track_origins())
661 __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
662 return *p;
663 }
__sanitizer_unaligned_store16(uu16 * p,u16 x)664 void __sanitizer_unaligned_store16(uu16 *p, u16 x) {
665 static_assert(sizeof(uu16) == sizeof(u16), "incompatible types");
666 u16 s;
667 internal_memcpy(&s, &__msan_param_tls[1], sizeof(uu16));
668 internal_memcpy((void *)MEM_TO_SHADOW((uptr)p), &s, sizeof(uu16));
669 if (s && __msan_get_track_origins())
670 if (uu32 o = __msan_param_origin_tls[2])
671 SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
672 *p = x;
673 }
__sanitizer_unaligned_store32(uu32 * p,u32 x)674 void __sanitizer_unaligned_store32(uu32 *p, u32 x) {
675 static_assert(sizeof(uu32) == sizeof(u32), "incompatible types");
676 u32 s;
677 internal_memcpy(&s, &__msan_param_tls[1], sizeof(uu32));
678 internal_memcpy((void *)MEM_TO_SHADOW((uptr)p), &s, sizeof(uu32));
679 if (s && __msan_get_track_origins())
680 if (uu32 o = __msan_param_origin_tls[2])
681 SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
682 *p = x;
683 }
__sanitizer_unaligned_store64(uu64 * p,u64 x)684 void __sanitizer_unaligned_store64(uu64 *p, u64 x) {
685 u64 s = __msan_param_tls[1];
686 *(uu64 *)MEM_TO_SHADOW((uptr)p) = s;
687 if (s && __msan_get_track_origins())
688 if (uu32 o = __msan_param_origin_tls[2])
689 SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
690 *p = x;
691 }
692
__msan_set_death_callback(void (* callback)(void))693 void __msan_set_death_callback(void (*callback)(void)) {
694 SetUserDieCallback(callback);
695 }
696
__msan_start_switch_fiber(const void * bottom,uptr size)697 void __msan_start_switch_fiber(const void *bottom, uptr size) {
698 MsanThread *t = GetCurrentThread();
699 if (!t) {
700 VReport(1, "__msan_start_switch_fiber called from unknown thread\n");
701 return;
702 }
703 t->StartSwitchFiber((uptr)bottom, size);
704 }
705
__msan_finish_switch_fiber(const void ** bottom_old,uptr * size_old)706 void __msan_finish_switch_fiber(const void **bottom_old, uptr *size_old) {
707 MsanThread *t = GetCurrentThread();
708 if (!t) {
709 VReport(1, "__msan_finish_switch_fiber called from unknown thread\n");
710 return;
711 }
712 t->FinishSwitchFiber((uptr *)bottom_old, (uptr *)size_old);
713
714 internal_memset(__msan_param_tls, 0, sizeof(__msan_param_tls));
715 internal_memset(__msan_retval_tls, 0, sizeof(__msan_retval_tls));
716 internal_memset(__msan_va_arg_tls, 0, sizeof(__msan_va_arg_tls));
717
718 if (__msan_get_track_origins()) {
719 internal_memset(__msan_param_origin_tls, 0,
720 sizeof(__msan_param_origin_tls));
721 internal_memset(&__msan_retval_origin_tls, 0,
722 sizeof(__msan_retval_origin_tls));
723 internal_memset(__msan_va_arg_origin_tls, 0,
724 sizeof(__msan_va_arg_origin_tls));
725 }
726 }
727
SANITIZER_INTERFACE_WEAK_DEF(const char *,__msan_default_options,void)728 SANITIZER_INTERFACE_WEAK_DEF(const char *, __msan_default_options, void) {
729 return "";
730 }
731
732 extern "C" {
733 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_print_stack_trace()734 void __sanitizer_print_stack_trace() {
735 GET_FATAL_STACK_TRACE_PC_BP(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME());
736 stack.Print();
737 }
738 } // extern "C"
739