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_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"
32 // ACHTUNG! No system header includes in this file.
34 using namespace __sanitizer
;
37 static THREADLOCAL
int msan_expect_umr
= 0;
38 static THREADLOCAL
int msan_expected_umr_found
= 0;
40 // Function argument shadow. Each argument starts at the next available 8-byte
42 SANITIZER_INTERFACE_ATTRIBUTE
43 THREADLOCAL u64 __msan_param_tls
[kMsanParamTlsSize
/ sizeof(u64
)];
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
)];
51 SANITIZER_INTERFACE_ATTRIBUTE
52 THREADLOCAL u64 __msan_retval_tls
[kMsanRetvalTlsSize
/ sizeof(u64
)];
54 SANITIZER_INTERFACE_ATTRIBUTE
55 THREADLOCAL u32 __msan_retval_origin_tls
;
57 SANITIZER_INTERFACE_ATTRIBUTE
58 ALIGNED(16) THREADLOCAL u64 __msan_va_arg_tls
[kMsanParamTlsSize
/ sizeof(u64
)];
60 SANITIZER_INTERFACE_ATTRIBUTE
61 THREADLOCAL u64 __msan_va_arg_overflow_size_tls
;
63 SANITIZER_INTERFACE_ATTRIBUTE
64 THREADLOCAL u32 __msan_origin_tls
;
66 static THREADLOCAL
int is_in_symbolizer
;
68 extern "C" SANITIZER_WEAK_ATTRIBUTE
const int __msan_track_origins
;
70 int __msan_get_track_origins() {
71 return &__msan_track_origins
? __msan_track_origins
: 0;
74 extern "C" SANITIZER_WEAK_ATTRIBUTE
const int __msan_keep_going
;
78 void EnterSymbolizer() { ++is_in_symbolizer
; }
79 void ExitSymbolizer() { --is_in_symbolizer
; }
80 bool IsInSymbolizer() { return is_in_symbolizer
; }
82 static Flags msan_flags
;
89 bool msan_init_is_running
;
91 int msan_report_count
= 0;
93 // Array of stack origins.
94 // FIXME: make it resizable.
95 static const uptr kNumStackOriginDescrs
= 1024 * 1024;
96 static const char *StackOriginDescr
[kNumStackOriginDescrs
];
97 static uptr StackOriginPC
[kNumStackOriginDescrs
];
98 static atomic_uint32_t NumStackOriginDescrs
;
100 void Flags::SetDefaults() {
101 #define MSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
102 #include "msan_flags.inc"
106 // keep_going is an old name for halt_on_error,
107 // and it has inverse meaning.
108 class FlagHandlerKeepGoing
: public FlagHandlerBase
{
109 bool *halt_on_error_
;
112 explicit FlagHandlerKeepGoing(bool *halt_on_error
)
113 : halt_on_error_(halt_on_error
) {}
114 bool Parse(const char *value
) final
{
116 FlagHandler
<bool> h(&tmp
);
117 if (!h
.Parse(value
)) return false;
118 *halt_on_error_
= !tmp
;
123 static void RegisterMsanFlags(FlagParser
*parser
, Flags
*f
) {
124 #define MSAN_FLAG(Type, Name, DefaultValue, Description) \
125 RegisterFlag(parser, #Name, Description, &f->Name);
126 #include "msan_flags.inc"
129 FlagHandlerKeepGoing
*fh_keep_going
= new (FlagParser::Alloc
) // NOLINT
130 FlagHandlerKeepGoing(&f
->halt_on_error
);
131 parser
->RegisterHandler("keep_going", fh_keep_going
,
132 "deprecated, use halt_on_error");
135 static void InitializeFlags() {
136 SetCommonFlagsDefaults();
139 cf
.CopyFrom(*common_flags());
140 cf
.external_symbolizer_path
= GetEnv("MSAN_SYMBOLIZER_PATH");
141 cf
.malloc_context_size
= 20;
142 cf
.handle_ioctl
= true;
143 // FIXME: test and enable.
144 cf
.check_printf
= false;
145 cf
.intercept_tls_get_addr
= true;
147 OverrideCommonFlags(cf
);
154 RegisterMsanFlags(&parser
, f
);
155 RegisterCommonFlags(&parser
);
157 #if MSAN_CONTAINS_UBSAN
158 __ubsan::Flags
*uf
= __ubsan::flags();
161 FlagParser ubsan_parser
;
162 __ubsan::RegisterUbsanFlags(&ubsan_parser
, uf
);
163 RegisterCommonFlags(&ubsan_parser
);
166 // Override from user-specified string.
167 if (__msan_default_options
)
168 parser
.ParseString(__msan_default_options());
169 #if MSAN_CONTAINS_UBSAN
170 const char *ubsan_default_options
= __ubsan::MaybeCallUbsanDefaultOptions();
171 ubsan_parser
.ParseString(ubsan_default_options
);
174 const char *msan_options
= GetEnv("MSAN_OPTIONS");
175 parser
.ParseString(msan_options
);
176 #if MSAN_CONTAINS_UBSAN
177 ubsan_parser
.ParseString(GetEnv("UBSAN_OPTIONS"));
179 VPrintf(1, "MSAN_OPTIONS: %s\n", msan_options
? msan_options
: "<empty>");
181 InitializeCommonFlags();
183 if (Verbosity()) ReportUnrecognizedFlags();
185 if (common_flags()->help
) parser
.PrintFlagDescriptions();
187 // Check if deprecated exit_code MSan flag is set.
188 if (f
->exit_code
!= -1) {
190 Printf("MSAN_OPTIONS=exit_code is deprecated! "
191 "Please use MSAN_OPTIONS=exitcode instead.\n");
193 cf
.CopyFrom(*common_flags());
194 cf
.exitcode
= f
->exit_code
;
195 OverrideCommonFlags(cf
);
198 // Check flag values:
199 if (f
->origin_history_size
< 0 ||
200 f
->origin_history_size
> Origin::kMaxDepth
) {
202 "Origin history size invalid: %d. Must be 0 (unlimited) or in [1, %d] "
204 f
->origin_history_size
, Origin::kMaxDepth
);
207 // Limiting to kStackDepotMaxUseCount / 2 to avoid overflow in
208 // StackDepotHandle::inc_use_count_unsafe.
209 if (f
->origin_history_per_stack_limit
< 0 ||
210 f
->origin_history_per_stack_limit
> kStackDepotMaxUseCount
/ 2) {
212 "Origin per-stack limit invalid: %d. Must be 0 (unlimited) or in [1, "
214 f
->origin_history_per_stack_limit
, kStackDepotMaxUseCount
/ 2);
217 if (f
->store_context_size
< 1) f
->store_context_size
= 1;
220 void GetStackTrace(BufferedStackTrace
*stack
, uptr max_s
, uptr pc
, uptr bp
,
221 bool request_fast_unwind
) {
222 MsanThread
*t
= GetCurrentThread();
223 if (!t
|| !StackTrace::WillUseFastUnwind(request_fast_unwind
)) {
224 // Block reports from our interceptors during _Unwind_Backtrace.
225 SymbolizerScope sym_scope
;
226 return stack
->Unwind(max_s
, pc
, bp
, nullptr, 0, 0, request_fast_unwind
);
228 stack
->Unwind(max_s
, pc
, bp
, nullptr, t
->stack_top(), t
->stack_bottom(),
229 request_fast_unwind
);
232 void PrintWarning(uptr pc
, uptr bp
) {
233 PrintWarningWithOrigin(pc
, bp
, __msan_origin_tls
);
236 void PrintWarningWithOrigin(uptr pc
, uptr bp
, u32 origin
) {
237 if (msan_expect_umr
) {
238 // Printf("Expected UMR\n");
239 __msan_origin_tls
= origin
;
240 msan_expected_umr_found
= 1;
246 GET_FATAL_STACK_TRACE_PC_BP(pc
, bp
);
249 (__msan_get_track_origins() && Origin::isValidId(origin
)) ? origin
: 0;
250 ReportUMR(&stack
, report_origin
);
252 if (__msan_get_track_origins() && !Origin::isValidId(origin
)) {
254 " ORIGIN: invalid (%x). Might be a bug in MemorySanitizer origin "
255 "tracking.\n This could still be a bug in your code, too!\n",
260 void UnpoisonParam(uptr n
) {
261 internal_memset(__msan_param_tls
, 0, n
* sizeof(*__msan_param_tls
));
264 // Backup MSan runtime TLS state.
265 // Implementation must be async-signal-safe.
266 // Instances of this class may live on the signal handler stack, and data size
268 void ScopedThreadLocalStateBackup::Backup() {
269 va_arg_overflow_size_tls
= __msan_va_arg_overflow_size_tls
;
272 void ScopedThreadLocalStateBackup::Restore() {
273 // A lame implementation that only keeps essential state and resets the rest.
274 __msan_va_arg_overflow_size_tls
= va_arg_overflow_size_tls
;
276 internal_memset(__msan_param_tls
, 0, sizeof(__msan_param_tls
));
277 internal_memset(__msan_retval_tls
, 0, sizeof(__msan_retval_tls
));
278 internal_memset(__msan_va_arg_tls
, 0, sizeof(__msan_va_arg_tls
));
280 if (__msan_get_track_origins()) {
281 internal_memset(&__msan_retval_origin_tls
, 0,
282 sizeof(__msan_retval_origin_tls
));
283 internal_memset(__msan_param_origin_tls
, 0,
284 sizeof(__msan_param_origin_tls
));
288 void UnpoisonThreadLocalState() {
291 const char *GetStackOriginDescr(u32 id
, uptr
*pc
) {
292 CHECK_LT(id
, kNumStackOriginDescrs
);
293 if (pc
) *pc
= StackOriginPC
[id
];
294 return StackOriginDescr
[id
];
297 u32
ChainOrigin(u32 id
, StackTrace
*stack
) {
298 MsanThread
*t
= GetCurrentThread();
299 if (t
&& t
->InSignalHandler())
302 Origin o
= Origin::FromRawId(id
);
303 stack
->tag
= StackTrace::TAG_UNKNOWN
;
304 Origin chained
= Origin::CreateChainedOrigin(o
, stack
);
305 return chained
.raw_id();
308 } // namespace __msan
312 using namespace __msan
;
314 #define MSAN_MAYBE_WARNING(type, size) \
315 void __msan_maybe_warning_##size(type s, u32 o) { \
316 GET_CALLER_PC_BP_SP; \
319 PrintWarningWithOrigin(pc, bp, o); \
320 if (__msan::flags()->halt_on_error) { \
321 Printf("Exiting\n"); \
327 MSAN_MAYBE_WARNING(u8
, 1)
328 MSAN_MAYBE_WARNING(u16
, 2)
329 MSAN_MAYBE_WARNING(u32
, 4)
330 MSAN_MAYBE_WARNING(u64
, 8)
332 #define MSAN_MAYBE_STORE_ORIGIN(type, size) \
333 void __msan_maybe_store_origin_##size(type s, void *p, u32 o) { \
335 if (__msan_get_track_origins() > 1) { \
336 GET_CALLER_PC_BP_SP; \
338 GET_STORE_STACK_TRACE_PC_BP(pc, bp); \
339 o = ChainOrigin(o, &stack); \
341 *(u32 *)MEM_TO_ORIGIN((uptr)p & ~3UL) = o; \
345 MSAN_MAYBE_STORE_ORIGIN(u8
, 1)
346 MSAN_MAYBE_STORE_ORIGIN(u16
, 2)
347 MSAN_MAYBE_STORE_ORIGIN(u32
, 4)
348 MSAN_MAYBE_STORE_ORIGIN(u64
, 8)
350 void __msan_warning() {
353 PrintWarning(pc
, bp
);
354 if (__msan::flags()->halt_on_error
) {
355 if (__msan::flags()->print_stats
)
362 void __msan_warning_noreturn() {
365 PrintWarning(pc
, bp
);
366 if (__msan::flags()->print_stats
)
373 CHECK(!msan_init_is_running
);
374 if (msan_inited
) return;
375 msan_init_is_running
= 1;
376 SanitizerToolName
= "MemorySanitizer";
378 AvoidCVE_2016_2143();
384 __sanitizer_set_report_path(common_flags()->log_path
);
386 InitializeInterceptors();
387 InstallAtExitHandler(); // Needs __cxa_atexit interceptor.
389 DisableCoreDumperIfNecessary();
390 if (StackSizeIsUnlimited()) {
391 VPrintf(1, "Unlimited stack, doing reexec\n");
392 // A reasonably large stack size. It is bigger than the usual 8Mb, because,
393 // well, the program could have been run with unlimited stack for a reason.
394 SetStackSizeLimitInBytes(32 * 1024 * 1024);
398 __msan_clear_on_return();
399 if (__msan_get_track_origins())
400 VPrintf(1, "msan_track_origins\n");
401 if (!InitShadow(__msan_get_track_origins())) {
402 Printf("FATAL: MemorySanitizer can not mmap the shadow memory.\n");
403 Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n");
404 Printf("FATAL: Disabling ASLR is known to cause this error.\n");
405 Printf("FATAL: If running under GDB, try "
406 "'set disable-randomization off'.\n");
411 Symbolizer::GetOrInit()->AddHooks(EnterSymbolizer
, ExitSymbolizer
);
413 InitializeCoverage(common_flags()->coverage
, common_flags()->coverage_dir
);
415 MsanTSDInit(MsanTSDDtor
);
419 MsanThread
*main_thread
= MsanThread::Create(nullptr, nullptr);
420 SetCurrentThread(main_thread
);
421 main_thread
->ThreadStart();
423 #if MSAN_CONTAINS_UBSAN
424 __ubsan::InitAsPlugin();
427 VPrintf(1, "MemorySanitizer init done\n");
429 msan_init_is_running
= 0;
433 void __msan_set_keep_going(int keep_going
) {
434 flags()->halt_on_error
= !keep_going
;
437 void __msan_set_expect_umr(int expect_umr
) {
439 msan_expected_umr_found
= 0;
440 } else if (!msan_expected_umr_found
) {
443 GET_FATAL_STACK_TRACE_PC_BP(pc
, bp
);
444 ReportExpectedUMRNotFound(&stack
);
447 msan_expect_umr
= expect_umr
;
450 void __msan_print_shadow(const void *x
, uptr size
) {
451 if (!MEM_IS_APP(x
)) {
452 Printf("Not a valid application address: %p\n", x
);
456 DescribeMemoryRange(x
, size
);
459 void __msan_dump_shadow(const void *x
, uptr size
) {
460 if (!MEM_IS_APP(x
)) {
461 Printf("Not a valid application address: %p\n", x
);
465 unsigned char *s
= (unsigned char*)MEM_TO_SHADOW(x
);
466 for (uptr i
= 0; i
< size
; i
++)
467 Printf("%x%x ", s
[i
] >> 4, s
[i
] & 0xf);
471 sptr
__msan_test_shadow(const void *x
, uptr size
) {
472 if (!MEM_IS_APP(x
)) return -1;
473 unsigned char *s
= (unsigned char *)MEM_TO_SHADOW((uptr
)x
);
474 for (uptr i
= 0; i
< size
; ++i
)
480 void __msan_check_mem_is_initialized(const void *x
, uptr size
) {
481 if (!__msan::flags()->report_umrs
) return;
482 sptr offset
= __msan_test_shadow(x
, size
);
488 ReportUMRInsideAddressRange(__func__
, x
, size
, offset
);
489 __msan::PrintWarningWithOrigin(pc
, bp
,
490 __msan_get_origin(((const char *)x
) + offset
));
491 if (__msan::flags()->halt_on_error
) {
497 int __msan_set_poison_in_malloc(int do_poison
) {
498 int old
= flags()->poison_in_malloc
;
499 flags()->poison_in_malloc
= do_poison
;
503 int __msan_has_dynamic_component() { return false; }
506 void __msan_clear_on_return() {
507 __msan_param_tls
[0] = 0;
510 void __msan_partial_poison(const void* data
, void* shadow
, uptr size
) {
511 internal_memcpy((void*)MEM_TO_SHADOW((uptr
)data
), shadow
, size
);
514 void __msan_load_unpoisoned(const void *src
, uptr size
, void *dst
) {
515 internal_memcpy(dst
, src
, size
);
516 __msan_unpoison(dst
, size
);
519 void __msan_set_origin(const void *a
, uptr size
, u32 origin
) {
520 if (__msan_get_track_origins()) SetOrigin(a
, size
, origin
);
523 // 'descr' is created at compile time and contains '----' in the beginning.
524 // When we see descr for the first time we replace '----' with a uniq id
525 // and set the origin to (id | (31-th bit)).
526 void __msan_set_alloca_origin(void *a
, uptr size
, char *descr
) {
527 __msan_set_alloca_origin4(a
, size
, descr
, 0);
530 void __msan_set_alloca_origin4(void *a
, uptr size
, char *descr
, uptr pc
) {
531 static const u32 dash
= '-';
532 static const u32 first_timer
=
533 dash
+ (dash
<< 8) + (dash
<< 16) + (dash
<< 24);
534 u32
*id_ptr
= (u32
*)descr
;
535 bool print
= false; // internal_strstr(descr + 4, "AllocaTOTest") != 0;
537 if (id
== first_timer
) {
538 u32 idx
= atomic_fetch_add(&NumStackOriginDescrs
, 1, memory_order_relaxed
);
539 CHECK_LT(idx
, kNumStackOriginDescrs
);
540 StackOriginDescr
[idx
] = descr
+ 4;
541 #if SANITIZER_PPC64V1
542 // On PowerPC64 ELFv1, the address of a function actually points to a
543 // three-doubleword data structure with the first field containing
544 // the address of the function's code.
546 pc
= *reinterpret_cast<uptr
*>(pc
);
548 StackOriginPC
[idx
] = pc
;
549 id
= Origin::CreateStackOrigin(idx
).raw_id();
552 Printf("First time: idx=%d id=%d %s %p \n", idx
, id
, descr
+ 4, pc
);
555 Printf("__msan_set_alloca_origin: descr=%s id=%x\n", descr
+ 4, id
);
556 __msan_set_origin(a
, size
, id
);
559 u32
__msan_chain_origin(u32 id
) {
562 GET_STORE_STACK_TRACE_PC_BP(pc
, bp
);
563 return ChainOrigin(id
, &stack
);
566 u32
__msan_get_origin(const void *a
) {
567 if (!__msan_get_track_origins()) return 0;
569 uptr aligned
= x
& ~3ULL;
570 uptr origin_ptr
= MEM_TO_ORIGIN(aligned
);
571 return *(u32
*)origin_ptr
;
574 int __msan_origin_is_descendant_or_same(u32 this_id
, u32 prev_id
) {
575 Origin o
= Origin::FromRawId(this_id
);
576 while (o
.raw_id() != prev_id
&& o
.isChainedOrigin())
577 o
= o
.getNextChainedOrigin(nullptr);
578 return o
.raw_id() == prev_id
;
581 u32
__msan_get_umr_origin() {
582 return __msan_origin_tls
;
585 u16
__sanitizer_unaligned_load16(const uu16
*p
) {
586 *(uu16
*)&__msan_retval_tls
[0] = *(uu16
*)MEM_TO_SHADOW((uptr
)p
);
587 if (__msan_get_track_origins())
588 __msan_retval_origin_tls
= GetOriginIfPoisoned((uptr
)p
, sizeof(*p
));
591 u32
__sanitizer_unaligned_load32(const uu32
*p
) {
592 *(uu32
*)&__msan_retval_tls
[0] = *(uu32
*)MEM_TO_SHADOW((uptr
)p
);
593 if (__msan_get_track_origins())
594 __msan_retval_origin_tls
= GetOriginIfPoisoned((uptr
)p
, sizeof(*p
));
597 u64
__sanitizer_unaligned_load64(const uu64
*p
) {
598 __msan_retval_tls
[0] = *(uu64
*)MEM_TO_SHADOW((uptr
)p
);
599 if (__msan_get_track_origins())
600 __msan_retval_origin_tls
= GetOriginIfPoisoned((uptr
)p
, sizeof(*p
));
603 void __sanitizer_unaligned_store16(uu16
*p
, u16 x
) {
604 u16 s
= *(uu16
*)&__msan_param_tls
[1];
605 *(uu16
*)MEM_TO_SHADOW((uptr
)p
) = s
;
606 if (s
&& __msan_get_track_origins())
607 if (uu32 o
= __msan_param_origin_tls
[2])
608 SetOriginIfPoisoned((uptr
)p
, (uptr
)&s
, sizeof(s
), o
);
611 void __sanitizer_unaligned_store32(uu32
*p
, u32 x
) {
612 u32 s
= *(uu32
*)&__msan_param_tls
[1];
613 *(uu32
*)MEM_TO_SHADOW((uptr
)p
) = s
;
614 if (s
&& __msan_get_track_origins())
615 if (uu32 o
= __msan_param_origin_tls
[2])
616 SetOriginIfPoisoned((uptr
)p
, (uptr
)&s
, sizeof(s
), o
);
619 void __sanitizer_unaligned_store64(uu64
*p
, u64 x
) {
620 u64 s
= __msan_param_tls
[1];
621 *(uu64
*)MEM_TO_SHADOW((uptr
)p
) = s
;
622 if (s
&& __msan_get_track_origins())
623 if (uu32 o
= __msan_param_origin_tls
[2])
624 SetOriginIfPoisoned((uptr
)p
, (uptr
)&s
, sizeof(s
), o
);
628 void __msan_set_death_callback(void (*callback
)(void)) {
629 SetUserDieCallback(callback
);
632 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
634 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
635 const char* __msan_default_options() { return ""; }
640 SANITIZER_INTERFACE_ATTRIBUTE
641 void __sanitizer_print_stack_trace() {
642 GET_FATAL_STACK_TRACE_PC_BP(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME());