1 //===-- msan.cc -----------------------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file is a part of MemorySanitizer.
12 // MemorySanitizer runtime.
13 //===----------------------------------------------------------------------===//
16 #include "msan_chained_origin_depot.h"
17 #include "msan_origin.h"
18 #include "msan_report.h"
19 #include "msan_thread.h"
20 #include "msan_poisoning.h"
21 #include "sanitizer_common/sanitizer_atomic.h"
22 #include "sanitizer_common/sanitizer_common.h"
23 #include "sanitizer_common/sanitizer_flags.h"
24 #include "sanitizer_common/sanitizer_flag_parser.h"
25 #include "sanitizer_common/sanitizer_libc.h"
26 #include "sanitizer_common/sanitizer_procmaps.h"
27 #include "sanitizer_common/sanitizer_stacktrace.h"
28 #include "sanitizer_common/sanitizer_symbolizer.h"
29 #include "sanitizer_common/sanitizer_stackdepot.h"
30 #include "ubsan/ubsan_flags.h"
31 #include "ubsan/ubsan_init.h"
33 // ACHTUNG! No system header includes in this file.
35 using namespace __sanitizer;
38 static THREADLOCAL int msan_expect_umr = 0;
39 static THREADLOCAL int msan_expected_umr_found = 0;
41 // Function argument shadow. Each argument starts at the next available 8-byte
43 SANITIZER_INTERFACE_ATTRIBUTE
44 THREADLOCAL u64 __msan_param_tls[kMsanParamTlsSize / sizeof(u64)];
46 // Function argument origin. Each argument starts at the same offset as the
47 // corresponding shadow in (__msan_param_tls). Slightly weird, but changing this
48 // would break compatibility with older prebuilt binaries.
49 SANITIZER_INTERFACE_ATTRIBUTE
50 THREADLOCAL u32 __msan_param_origin_tls[kMsanParamTlsSize / sizeof(u32)];
52 SANITIZER_INTERFACE_ATTRIBUTE
53 THREADLOCAL u64 __msan_retval_tls[kMsanRetvalTlsSize / sizeof(u64)];
55 SANITIZER_INTERFACE_ATTRIBUTE
56 THREADLOCAL u32 __msan_retval_origin_tls;
58 SANITIZER_INTERFACE_ATTRIBUTE
59 ALIGNED(16) THREADLOCAL u64 __msan_va_arg_tls[kMsanParamTlsSize / sizeof(u64)];
61 SANITIZER_INTERFACE_ATTRIBUTE
62 THREADLOCAL u64 __msan_va_arg_overflow_size_tls;
64 SANITIZER_INTERFACE_ATTRIBUTE
65 THREADLOCAL u32 __msan_origin_tls;
67 static THREADLOCAL int is_in_symbolizer;
69 extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_track_origins;
71 int __msan_get_track_origins() {
72 return &__msan_track_origins ? __msan_track_origins : 0;
75 extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_keep_going;
79 void EnterSymbolizer() { ++is_in_symbolizer; }
80 void ExitSymbolizer() { --is_in_symbolizer; }
81 bool IsInSymbolizer() { return is_in_symbolizer; }
83 static Flags msan_flags;
90 bool msan_init_is_running;
92 int msan_report_count = 0;
94 // Array of stack origins.
95 // FIXME: make it resizable.
96 static const uptr kNumStackOriginDescrs = 1024 * 1024;
97 static const char *StackOriginDescr[kNumStackOriginDescrs];
98 static uptr StackOriginPC[kNumStackOriginDescrs];
99 static atomic_uint32_t NumStackOriginDescrs;
101 void Flags::SetDefaults() {
102 #define MSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
103 #include "msan_flags.inc"
107 // keep_going is an old name for halt_on_error,
108 // and it has inverse meaning.
109 class FlagHandlerKeepGoing : public FlagHandlerBase {
110 bool *halt_on_error_;
113 explicit FlagHandlerKeepGoing(bool *halt_on_error)
114 : halt_on_error_(halt_on_error) {}
115 bool Parse(const char *value) final {
117 FlagHandler<bool> h(&tmp);
118 if (!h.Parse(value)) return false;
119 *halt_on_error_ = !tmp;
124 static void RegisterMsanFlags(FlagParser *parser, Flags *f) {
125 #define MSAN_FLAG(Type, Name, DefaultValue, Description) \
126 RegisterFlag(parser, #Name, Description, &f->Name);
127 #include "msan_flags.inc"
130 FlagHandlerKeepGoing *fh_keep_going = new (FlagParser::Alloc) // NOLINT
131 FlagHandlerKeepGoing(&f->halt_on_error);
132 parser->RegisterHandler("keep_going", fh_keep_going,
133 "deprecated, use halt_on_error");
136 static void InitializeFlags() {
137 SetCommonFlagsDefaults();
140 cf.CopyFrom(*common_flags());
141 cf.external_symbolizer_path = GetEnv("MSAN_SYMBOLIZER_PATH");
142 cf.malloc_context_size = 20;
143 cf.handle_ioctl = true;
144 // FIXME: test and enable.
145 cf.check_printf = false;
146 cf.intercept_tls_get_addr = true;
148 OverrideCommonFlags(cf);
155 RegisterMsanFlags(&parser, f);
156 RegisterCommonFlags(&parser);
158 #if MSAN_CONTAINS_UBSAN
159 __ubsan::Flags *uf = __ubsan::flags();
162 FlagParser ubsan_parser;
163 __ubsan::RegisterUbsanFlags(&ubsan_parser, uf);
164 RegisterCommonFlags(&ubsan_parser);
167 // Override from user-specified string.
168 if (__msan_default_options)
169 parser.ParseString(__msan_default_options());
170 #if MSAN_CONTAINS_UBSAN
171 const char *ubsan_default_options = __ubsan::MaybeCallUbsanDefaultOptions();
172 ubsan_parser.ParseString(ubsan_default_options);
175 const char *msan_options = GetEnv("MSAN_OPTIONS");
176 parser.ParseString(msan_options);
177 #if MSAN_CONTAINS_UBSAN
178 ubsan_parser.ParseString(GetEnv("UBSAN_OPTIONS"));
180 VPrintf(1, "MSAN_OPTIONS: %s\n", msan_options ? msan_options : "<empty>");
182 InitializeCommonFlags();
184 if (Verbosity()) ReportUnrecognizedFlags();
186 if (common_flags()->help) parser.PrintFlagDescriptions();
188 // Check if deprecated exit_code MSan flag is set.
189 if (f->exit_code != -1) {
191 Printf("MSAN_OPTIONS=exit_code is deprecated! "
192 "Please use MSAN_OPTIONS=exitcode instead.\n");
194 cf.CopyFrom(*common_flags());
195 cf.exitcode = f->exit_code;
196 OverrideCommonFlags(cf);
199 // Check flag values:
200 if (f->origin_history_size < 0 ||
201 f->origin_history_size > Origin::kMaxDepth) {
203 "Origin history size invalid: %d. Must be 0 (unlimited) or in [1, %d] "
205 f->origin_history_size, Origin::kMaxDepth);
208 // Limiting to kStackDepotMaxUseCount / 2 to avoid overflow in
209 // StackDepotHandle::inc_use_count_unsafe.
210 if (f->origin_history_per_stack_limit < 0 ||
211 f->origin_history_per_stack_limit > kStackDepotMaxUseCount / 2) {
213 "Origin per-stack limit invalid: %d. Must be 0 (unlimited) or in [1, "
215 f->origin_history_per_stack_limit, kStackDepotMaxUseCount / 2);
218 if (f->store_context_size < 1) f->store_context_size = 1;
221 void GetStackTrace(BufferedStackTrace *stack, uptr max_s, uptr pc, uptr bp,
222 void *context, bool request_fast_unwind) {
223 MsanThread *t = GetCurrentThread();
224 if (!t || !StackTrace::WillUseFastUnwind(request_fast_unwind)) {
225 // Block reports from our interceptors during _Unwind_Backtrace.
226 SymbolizerScope sym_scope;
227 return stack->Unwind(max_s, pc, bp, context, 0, 0, request_fast_unwind);
229 stack->Unwind(max_s, pc, bp, context, t->stack_top(), t->stack_bottom(),
230 request_fast_unwind);
233 void PrintWarning(uptr pc, uptr bp) {
234 PrintWarningWithOrigin(pc, bp, __msan_origin_tls);
237 void PrintWarningWithOrigin(uptr pc, uptr bp, u32 origin) {
238 if (msan_expect_umr) {
239 // Printf("Expected UMR\n");
240 __msan_origin_tls = origin;
241 msan_expected_umr_found = 1;
247 GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
250 (__msan_get_track_origins() && Origin::isValidId(origin)) ? origin : 0;
251 ReportUMR(&stack, report_origin);
253 if (__msan_get_track_origins() && !Origin::isValidId(origin)) {
255 " ORIGIN: invalid (%x). Might be a bug in MemorySanitizer origin "
256 "tracking.\n This could still be a bug in your code, too!\n",
261 void UnpoisonParam(uptr n) {
262 internal_memset(__msan_param_tls, 0, n * sizeof(*__msan_param_tls));
265 // Backup MSan runtime TLS state.
266 // Implementation must be async-signal-safe.
267 // Instances of this class may live on the signal handler stack, and data size
269 void ScopedThreadLocalStateBackup::Backup() {
270 va_arg_overflow_size_tls = __msan_va_arg_overflow_size_tls;
273 void ScopedThreadLocalStateBackup::Restore() {
274 // A lame implementation that only keeps essential state and resets the rest.
275 __msan_va_arg_overflow_size_tls = va_arg_overflow_size_tls;
277 internal_memset(__msan_param_tls, 0, sizeof(__msan_param_tls));
278 internal_memset(__msan_retval_tls, 0, sizeof(__msan_retval_tls));
279 internal_memset(__msan_va_arg_tls, 0, sizeof(__msan_va_arg_tls));
281 if (__msan_get_track_origins()) {
282 internal_memset(&__msan_retval_origin_tls, 0,
283 sizeof(__msan_retval_origin_tls));
284 internal_memset(__msan_param_origin_tls, 0,
285 sizeof(__msan_param_origin_tls));
289 void UnpoisonThreadLocalState() {
292 const char *GetStackOriginDescr(u32 id, uptr *pc) {
293 CHECK_LT(id, kNumStackOriginDescrs);
294 if (pc) *pc = StackOriginPC[id];
295 return StackOriginDescr[id];
298 u32 ChainOrigin(u32 id, StackTrace *stack) {
299 MsanThread *t = GetCurrentThread();
300 if (t && t->InSignalHandler())
303 Origin o = Origin::FromRawId(id);
304 stack->tag = StackTrace::TAG_UNKNOWN;
305 Origin chained = Origin::CreateChainedOrigin(o, stack);
306 return chained.raw_id();
309 } // namespace __msan
313 using namespace __msan;
315 #define MSAN_MAYBE_WARNING(type, size) \
316 void __msan_maybe_warning_##size(type s, u32 o) { \
317 GET_CALLER_PC_BP_SP; \
320 PrintWarningWithOrigin(pc, bp, o); \
321 if (__msan::flags()->halt_on_error) { \
322 Printf("Exiting\n"); \
328 MSAN_MAYBE_WARNING(u8, 1)
329 MSAN_MAYBE_WARNING(u16, 2)
330 MSAN_MAYBE_WARNING(u32, 4)
331 MSAN_MAYBE_WARNING(u64, 8)
333 #define MSAN_MAYBE_STORE_ORIGIN(type, size) \
334 void __msan_maybe_store_origin_##size(type s, void *p, u32 o) { \
336 if (__msan_get_track_origins() > 1) { \
337 GET_CALLER_PC_BP_SP; \
339 GET_STORE_STACK_TRACE_PC_BP(pc, bp); \
340 o = ChainOrigin(o, &stack); \
342 *(u32 *)MEM_TO_ORIGIN((uptr)p & ~3UL) = o; \
346 MSAN_MAYBE_STORE_ORIGIN(u8, 1)
347 MSAN_MAYBE_STORE_ORIGIN(u16, 2)
348 MSAN_MAYBE_STORE_ORIGIN(u32, 4)
349 MSAN_MAYBE_STORE_ORIGIN(u64, 8)
351 void __msan_warning() {
354 PrintWarning(pc, bp);
355 if (__msan::flags()->halt_on_error) {
356 if (__msan::flags()->print_stats)
363 void __msan_warning_noreturn() {
366 PrintWarning(pc, bp);
367 if (__msan::flags()->print_stats)
373 static void OnStackUnwind(const SignalContext &sig, const void *,
374 BufferedStackTrace *stack) {
375 GetStackTrace(stack, kStackTraceMax, sig.pc, sig.bp, sig.context,
376 common_flags()->fast_unwind_on_fatal);
379 static void MsanOnDeadlySignal(int signo, void *siginfo, void *context) {
380 HandleDeadlySignal(siginfo, context, GetTid(), &OnStackUnwind, nullptr);
383 static void MsanCheckFailed(const char *file, int line, const char *cond,
385 Report("MemorySanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n", file,
386 line, cond, (uptr)v1, (uptr)v2);
387 PRINT_CURRENT_STACK_CHECK();
392 CHECK(!msan_init_is_running);
393 if (msan_inited) return;
394 msan_init_is_running = 1;
395 SanitizerToolName = "MemorySanitizer";
397 AvoidCVE_2016_2143();
403 // Install tool-specific callbacks in sanitizer_common.
404 SetCheckFailedCallback(MsanCheckFailed);
406 __sanitizer_set_report_path(common_flags()->log_path);
408 InitializeInterceptors();
410 InstallDeadlySignalHandlers(MsanOnDeadlySignal);
411 InstallAtExitHandler(); // Needs __cxa_atexit interceptor.
413 DisableCoreDumperIfNecessary();
414 if (StackSizeIsUnlimited()) {
415 VPrintf(1, "Unlimited stack, doing reexec\n");
416 // A reasonably large stack size. It is bigger than the usual 8Mb, because,
417 // well, the program could have been run with unlimited stack for a reason.
418 SetStackSizeLimitInBytes(32 * 1024 * 1024);
422 __msan_clear_on_return();
423 if (__msan_get_track_origins())
424 VPrintf(1, "msan_track_origins\n");
425 if (!InitShadow(__msan_get_track_origins())) {
426 Printf("FATAL: MemorySanitizer can not mmap the shadow memory.\n");
427 Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n");
428 Printf("FATAL: Disabling ASLR is known to cause this error.\n");
429 Printf("FATAL: If running under GDB, try "
430 "'set disable-randomization off'.\n");
435 Symbolizer::GetOrInit()->AddHooks(EnterSymbolizer, ExitSymbolizer);
437 InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
439 MsanTSDInit(MsanTSDDtor);
443 MsanThread *main_thread = MsanThread::Create(nullptr, nullptr);
444 SetCurrentThread(main_thread);
445 main_thread->ThreadStart();
447 #if MSAN_CONTAINS_UBSAN
448 __ubsan::InitAsPlugin();
451 VPrintf(1, "MemorySanitizer init done\n");
453 msan_init_is_running = 0;
457 void __msan_set_keep_going(int keep_going) {
458 flags()->halt_on_error = !keep_going;
461 void __msan_set_expect_umr(int expect_umr) {
463 msan_expected_umr_found = 0;
464 } else if (!msan_expected_umr_found) {
467 GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
468 ReportExpectedUMRNotFound(&stack);
471 msan_expect_umr = expect_umr;
474 void __msan_print_shadow(const void *x, uptr size) {
475 if (!MEM_IS_APP(x)) {
476 Printf("Not a valid application address: %p\n", x);
480 DescribeMemoryRange(x, size);
483 void __msan_dump_shadow(const void *x, uptr size) {
484 if (!MEM_IS_APP(x)) {
485 Printf("Not a valid application address: %p\n", x);
489 unsigned char *s = (unsigned char*)MEM_TO_SHADOW(x);
490 for (uptr i = 0; i < size; i++)
491 Printf("%x%x ", s[i] >> 4, s[i] & 0xf);
495 sptr __msan_test_shadow(const void *x, uptr size) {
496 if (!MEM_IS_APP(x)) return -1;
497 unsigned char *s = (unsigned char *)MEM_TO_SHADOW((uptr)x);
498 for (uptr i = 0; i < size; ++i)
504 void __msan_check_mem_is_initialized(const void *x, uptr size) {
505 if (!__msan::flags()->report_umrs) return;
506 sptr offset = __msan_test_shadow(x, size);
512 ReportUMRInsideAddressRange(__func__, x, size, offset);
513 __msan::PrintWarningWithOrigin(pc, bp,
514 __msan_get_origin(((const char *)x) + offset));
515 if (__msan::flags()->halt_on_error) {
521 int __msan_set_poison_in_malloc(int do_poison) {
522 int old = flags()->poison_in_malloc;
523 flags()->poison_in_malloc = do_poison;
527 int __msan_has_dynamic_component() { return false; }
530 void __msan_clear_on_return() {
531 __msan_param_tls[0] = 0;
534 void __msan_partial_poison(const void* data, void* shadow, uptr size) {
535 internal_memcpy((void*)MEM_TO_SHADOW((uptr)data), shadow, size);
538 void __msan_load_unpoisoned(const void *src, uptr size, void *dst) {
539 internal_memcpy(dst, src, size);
540 __msan_unpoison(dst, size);
543 void __msan_set_origin(const void *a, uptr size, u32 origin) {
544 if (__msan_get_track_origins()) SetOrigin(a, size, origin);
547 // 'descr' is created at compile time and contains '----' in the beginning.
548 // When we see descr for the first time we replace '----' with a uniq id
549 // and set the origin to (id | (31-th bit)).
550 void __msan_set_alloca_origin(void *a, uptr size, char *descr) {
551 __msan_set_alloca_origin4(a, size, descr, 0);
554 void __msan_set_alloca_origin4(void *a, uptr size, char *descr, uptr pc) {
555 static const u32 dash = '-';
556 static const u32 first_timer =
557 dash + (dash << 8) + (dash << 16) + (dash << 24);
558 u32 *id_ptr = (u32*)descr;
559 bool print = false; // internal_strstr(descr + 4, "AllocaTOTest") != 0;
561 if (id == first_timer) {
562 u32 idx = atomic_fetch_add(&NumStackOriginDescrs, 1, memory_order_relaxed);
563 CHECK_LT(idx, kNumStackOriginDescrs);
564 StackOriginDescr[idx] = descr + 4;
565 #if SANITIZER_PPC64V1
566 // On PowerPC64 ELFv1, the address of a function actually points to a
567 // three-doubleword data structure with the first field containing
568 // the address of the function's code.
570 pc = *reinterpret_cast<uptr*>(pc);
572 StackOriginPC[idx] = pc;
573 id = Origin::CreateStackOrigin(idx).raw_id();
576 Printf("First time: idx=%d id=%d %s %p \n", idx, id, descr + 4, pc);
579 Printf("__msan_set_alloca_origin: descr=%s id=%x\n", descr + 4, id);
580 __msan_set_origin(a, size, id);
583 u32 __msan_chain_origin(u32 id) {
586 GET_STORE_STACK_TRACE_PC_BP(pc, bp);
587 return ChainOrigin(id, &stack);
590 u32 __msan_get_origin(const void *a) {
591 if (!__msan_get_track_origins()) return 0;
593 uptr aligned = x & ~3ULL;
594 uptr origin_ptr = MEM_TO_ORIGIN(aligned);
595 return *(u32*)origin_ptr;
598 int __msan_origin_is_descendant_or_same(u32 this_id, u32 prev_id) {
599 Origin o = Origin::FromRawId(this_id);
600 while (o.raw_id() != prev_id && o.isChainedOrigin())
601 o = o.getNextChainedOrigin(nullptr);
602 return o.raw_id() == prev_id;
605 u32 __msan_get_umr_origin() {
606 return __msan_origin_tls;
609 u16 __sanitizer_unaligned_load16(const uu16 *p) {
610 *(uu16 *)&__msan_retval_tls[0] = *(uu16 *)MEM_TO_SHADOW((uptr)p);
611 if (__msan_get_track_origins())
612 __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
615 u32 __sanitizer_unaligned_load32(const uu32 *p) {
616 *(uu32 *)&__msan_retval_tls[0] = *(uu32 *)MEM_TO_SHADOW((uptr)p);
617 if (__msan_get_track_origins())
618 __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
621 u64 __sanitizer_unaligned_load64(const uu64 *p) {
622 __msan_retval_tls[0] = *(uu64 *)MEM_TO_SHADOW((uptr)p);
623 if (__msan_get_track_origins())
624 __msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
627 void __sanitizer_unaligned_store16(uu16 *p, u16 x) {
628 u16 s = *(uu16 *)&__msan_param_tls[1];
629 *(uu16 *)MEM_TO_SHADOW((uptr)p) = s;
630 if (s && __msan_get_track_origins())
631 if (uu32 o = __msan_param_origin_tls[2])
632 SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
635 void __sanitizer_unaligned_store32(uu32 *p, u32 x) {
636 u32 s = *(uu32 *)&__msan_param_tls[1];
637 *(uu32 *)MEM_TO_SHADOW((uptr)p) = s;
638 if (s && __msan_get_track_origins())
639 if (uu32 o = __msan_param_origin_tls[2])
640 SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
643 void __sanitizer_unaligned_store64(uu64 *p, u64 x) {
644 u64 s = __msan_param_tls[1];
645 *(uu64 *)MEM_TO_SHADOW((uptr)p) = s;
646 if (s && __msan_get_track_origins())
647 if (uu32 o = __msan_param_origin_tls[2])
648 SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
652 void __msan_set_death_callback(void (*callback)(void)) {
653 SetUserDieCallback(callback);
656 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
658 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
659 const char* __msan_default_options() { return ""; }
664 SANITIZER_INTERFACE_ATTRIBUTE
665 void __sanitizer_print_stack_trace() {
666 GET_FATAL_STACK_TRACE_PC_BP(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME());