1 //===-- asan_report.cc ----------------------------------------------------===//
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 // This file is a part of AddressSanitizer, an address sanity checker.
11 //
12 // This file contains error reporting code.
13 //===----------------------------------------------------------------------===//
14 #include "asan_flags.h"
15 #include "asan_internal.h"
16 #include "asan_mapping.h"
17 #include "asan_report.h"
18 #include "asan_stack.h"
19 #include "asan_thread.h"
20 #include "sanitizer_common/sanitizer_common.h"
21 #include "sanitizer_common/sanitizer_flags.h"
22 #include "sanitizer_common/sanitizer_report_decorator.h"
23 #include "sanitizer_common/sanitizer_stackdepot.h"
24 #include "sanitizer_common/sanitizer_symbolizer.h"
25
26 namespace __asan {
27
28 // -------------------- User-specified callbacks ----------------- {{{1
29 static void (*error_report_callback)(const char*);
30 static char *error_message_buffer = 0;
31 static uptr error_message_buffer_pos = 0;
32 static uptr error_message_buffer_size = 0;
33
AppendToErrorMessageBuffer(const char * buffer)34 void AppendToErrorMessageBuffer(const char *buffer) {
35 if (error_message_buffer) {
36 uptr length = internal_strlen(buffer);
37 CHECK_GE(error_message_buffer_size, error_message_buffer_pos);
38 uptr remaining = error_message_buffer_size - error_message_buffer_pos;
39 internal_strncpy(error_message_buffer + error_message_buffer_pos,
40 buffer, remaining);
41 error_message_buffer[error_message_buffer_size - 1] = '\0';
42 // FIXME: reallocate the buffer instead of truncating the message.
43 error_message_buffer_pos += remaining > length ? length : remaining;
44 }
45 }
46
47 // ---------------------- Decorator ------------------------------ {{{1
48 class Decorator: public __sanitizer::SanitizerCommonDecorator {
49 public:
Decorator()50 Decorator() : SanitizerCommonDecorator() { }
Access()51 const char *Access() { return Blue(); }
EndAccess()52 const char *EndAccess() { return Default(); }
Location()53 const char *Location() { return Green(); }
EndLocation()54 const char *EndLocation() { return Default(); }
Allocation()55 const char *Allocation() { return Magenta(); }
EndAllocation()56 const char *EndAllocation() { return Default(); }
57
ShadowByte(u8 byte)58 const char *ShadowByte(u8 byte) {
59 switch (byte) {
60 case kAsanHeapLeftRedzoneMagic:
61 case kAsanHeapRightRedzoneMagic:
62 return Red();
63 case kAsanHeapFreeMagic:
64 return Magenta();
65 case kAsanStackLeftRedzoneMagic:
66 case kAsanStackMidRedzoneMagic:
67 case kAsanStackRightRedzoneMagic:
68 case kAsanStackPartialRedzoneMagic:
69 return Red();
70 case kAsanStackAfterReturnMagic:
71 return Magenta();
72 case kAsanInitializationOrderMagic:
73 return Cyan();
74 case kAsanUserPoisonedMemoryMagic:
75 case kAsanContiguousContainerOOBMagic:
76 return Blue();
77 case kAsanStackUseAfterScopeMagic:
78 return Magenta();
79 case kAsanGlobalRedzoneMagic:
80 return Red();
81 case kAsanInternalHeapMagic:
82 return Yellow();
83 default:
84 return Default();
85 }
86 }
EndShadowByte()87 const char *EndShadowByte() { return Default(); }
88 };
89
90 // ---------------------- Helper functions ----------------------- {{{1
91
PrintShadowByte(InternalScopedString * str,const char * before,u8 byte,const char * after="\\n")92 static void PrintShadowByte(InternalScopedString *str, const char *before,
93 u8 byte, const char *after = "\n") {
94 Decorator d;
95 str->append("%s%s%x%x%s%s", before, d.ShadowByte(byte), byte >> 4, byte & 15,
96 d.EndShadowByte(), after);
97 }
98
PrintShadowBytes(InternalScopedString * str,const char * before,u8 * bytes,u8 * guilty,uptr n)99 static void PrintShadowBytes(InternalScopedString *str, const char *before,
100 u8 *bytes, u8 *guilty, uptr n) {
101 Decorator d;
102 if (before) str->append("%s%p:", before, bytes);
103 for (uptr i = 0; i < n; i++) {
104 u8 *p = bytes + i;
105 const char *before =
106 p == guilty ? "[" : (p - 1 == guilty && i != 0) ? "" : " ";
107 const char *after = p == guilty ? "]" : "";
108 PrintShadowByte(str, before, *p, after);
109 }
110 str->append("\n");
111 }
112
PrintLegend(InternalScopedString * str)113 static void PrintLegend(InternalScopedString *str) {
114 str->append(
115 "Shadow byte legend (one shadow byte represents %d "
116 "application bytes):\n",
117 (int)SHADOW_GRANULARITY);
118 PrintShadowByte(str, " Addressable: ", 0);
119 str->append(" Partially addressable: ");
120 for (u8 i = 1; i < SHADOW_GRANULARITY; i++) PrintShadowByte(str, "", i, " ");
121 str->append("\n");
122 PrintShadowByte(str, " Heap left redzone: ",
123 kAsanHeapLeftRedzoneMagic);
124 PrintShadowByte(str, " Heap right redzone: ",
125 kAsanHeapRightRedzoneMagic);
126 PrintShadowByte(str, " Freed heap region: ", kAsanHeapFreeMagic);
127 PrintShadowByte(str, " Stack left redzone: ",
128 kAsanStackLeftRedzoneMagic);
129 PrintShadowByte(str, " Stack mid redzone: ",
130 kAsanStackMidRedzoneMagic);
131 PrintShadowByte(str, " Stack right redzone: ",
132 kAsanStackRightRedzoneMagic);
133 PrintShadowByte(str, " Stack partial redzone: ",
134 kAsanStackPartialRedzoneMagic);
135 PrintShadowByte(str, " Stack after return: ",
136 kAsanStackAfterReturnMagic);
137 PrintShadowByte(str, " Stack use after scope: ",
138 kAsanStackUseAfterScopeMagic);
139 PrintShadowByte(str, " Global redzone: ", kAsanGlobalRedzoneMagic);
140 PrintShadowByte(str, " Global init order: ",
141 kAsanInitializationOrderMagic);
142 PrintShadowByte(str, " Poisoned by user: ",
143 kAsanUserPoisonedMemoryMagic);
144 PrintShadowByte(str, " Container overflow: ",
145 kAsanContiguousContainerOOBMagic);
146 PrintShadowByte(str, " ASan internal: ", kAsanInternalHeapMagic);
147 }
148
PrintShadowMemoryForAddress(uptr addr)149 static void PrintShadowMemoryForAddress(uptr addr) {
150 if (!AddrIsInMem(addr)) return;
151 uptr shadow_addr = MemToShadow(addr);
152 const uptr n_bytes_per_row = 16;
153 uptr aligned_shadow = shadow_addr & ~(n_bytes_per_row - 1);
154 InternalScopedString str(4096 * 8);
155 str.append("Shadow bytes around the buggy address:\n");
156 for (int i = -5; i <= 5; i++) {
157 const char *prefix = (i == 0) ? "=>" : " ";
158 PrintShadowBytes(&str, prefix, (u8 *)(aligned_shadow + i * n_bytes_per_row),
159 (u8 *)shadow_addr, n_bytes_per_row);
160 }
161 if (flags()->print_legend) PrintLegend(&str);
162 Printf("%s", str.data());
163 }
164
PrintZoneForPointer(uptr ptr,uptr zone_ptr,const char * zone_name)165 static void PrintZoneForPointer(uptr ptr, uptr zone_ptr,
166 const char *zone_name) {
167 if (zone_ptr) {
168 if (zone_name) {
169 Printf("malloc_zone_from_ptr(%p) = %p, which is %s\n",
170 ptr, zone_ptr, zone_name);
171 } else {
172 Printf("malloc_zone_from_ptr(%p) = %p, which doesn't have a name\n",
173 ptr, zone_ptr);
174 }
175 } else {
176 Printf("malloc_zone_from_ptr(%p) = 0\n", ptr);
177 }
178 }
179
DescribeThread(AsanThread * t)180 static void DescribeThread(AsanThread *t) {
181 if (t)
182 DescribeThread(t->context());
183 }
184
185 // ---------------------- Address Descriptions ------------------- {{{1
186
IsASCII(unsigned char c)187 static bool IsASCII(unsigned char c) {
188 return /*0x00 <= c &&*/ c <= 0x7F;
189 }
190
MaybeDemangleGlobalName(const char * name)191 static const char *MaybeDemangleGlobalName(const char *name) {
192 // We can spoil names of globals with C linkage, so use an heuristic
193 // approach to check if the name should be demangled.
194 bool should_demangle = false;
195 if (name[0] == '_' && name[1] == 'Z')
196 should_demangle = true;
197 else if (SANITIZER_WINDOWS && name[0] == '\01' && name[1] == '?')
198 should_demangle = true;
199
200 return should_demangle ? Symbolizer::Get()->Demangle(name) : name;
201 }
202
203 // Check if the global is a zero-terminated ASCII string. If so, print it.
PrintGlobalNameIfASCII(InternalScopedString * str,const __asan_global & g)204 static void PrintGlobalNameIfASCII(InternalScopedString *str,
205 const __asan_global &g) {
206 for (uptr p = g.beg; p < g.beg + g.size - 1; p++) {
207 unsigned char c = *(unsigned char*)p;
208 if (c == '\0' || !IsASCII(c)) return;
209 }
210 if (*(char*)(g.beg + g.size - 1) != '\0') return;
211 str->append(" '%s' is ascii string '%s'\n", MaybeDemangleGlobalName(g.name),
212 (char *)g.beg);
213 }
214
GlobalFilename(const __asan_global & g)215 static const char *GlobalFilename(const __asan_global &g) {
216 const char *res = g.module_name;
217 // Prefer the filename from source location, if is available.
218 if (g.location)
219 res = g.location->filename;
220 CHECK(res);
221 return res;
222 }
223
PrintGlobalLocation(InternalScopedString * str,const __asan_global & g)224 static void PrintGlobalLocation(InternalScopedString *str,
225 const __asan_global &g) {
226 str->append("%s", GlobalFilename(g));
227 if (!g.location)
228 return;
229 if (g.location->line_no)
230 str->append(":%d", g.location->line_no);
231 if (g.location->column_no)
232 str->append(":%d", g.location->column_no);
233 }
234
DescribeAddressRelativeToGlobal(uptr addr,uptr size,const __asan_global & g)235 bool DescribeAddressRelativeToGlobal(uptr addr, uptr size,
236 const __asan_global &g) {
237 static const uptr kMinimalDistanceFromAnotherGlobal = 64;
238 if (addr <= g.beg - kMinimalDistanceFromAnotherGlobal) return false;
239 if (addr >= g.beg + g.size_with_redzone) return false;
240 InternalScopedString str(4096);
241 Decorator d;
242 str.append("%s", d.Location());
243 if (addr < g.beg) {
244 str.append("%p is located %zd bytes to the left", (void *)addr,
245 g.beg - addr);
246 } else if (addr + size > g.beg + g.size) {
247 if (addr < g.beg + g.size)
248 addr = g.beg + g.size;
249 str.append("%p is located %zd bytes to the right", (void *)addr,
250 addr - (g.beg + g.size));
251 } else {
252 // Can it happen?
253 str.append("%p is located %zd bytes inside", (void *)addr, addr - g.beg);
254 }
255 str.append(" of global variable '%s' defined in '",
256 MaybeDemangleGlobalName(g.name));
257 PrintGlobalLocation(&str, g);
258 str.append("' (0x%zx) of size %zu\n", g.beg, g.size);
259 str.append("%s", d.EndLocation());
260 PrintGlobalNameIfASCII(&str, g);
261 Printf("%s", str.data());
262 return true;
263 }
264
DescribeAddressIfShadow(uptr addr)265 bool DescribeAddressIfShadow(uptr addr) {
266 if (AddrIsInMem(addr))
267 return false;
268 static const char kAddrInShadowReport[] =
269 "Address %p is located in the %s.\n";
270 if (AddrIsInShadowGap(addr)) {
271 Printf(kAddrInShadowReport, addr, "shadow gap area");
272 return true;
273 }
274 if (AddrIsInHighShadow(addr)) {
275 Printf(kAddrInShadowReport, addr, "high shadow area");
276 return true;
277 }
278 if (AddrIsInLowShadow(addr)) {
279 Printf(kAddrInShadowReport, addr, "low shadow area");
280 return true;
281 }
282 CHECK(0 && "Address is not in memory and not in shadow?");
283 return false;
284 }
285
286 // Return " (thread_name) " or an empty string if the name is empty.
ThreadNameWithParenthesis(AsanThreadContext * t,char buff[],uptr buff_len)287 const char *ThreadNameWithParenthesis(AsanThreadContext *t, char buff[],
288 uptr buff_len) {
289 const char *name = t->name;
290 if (name[0] == '\0') return "";
291 buff[0] = 0;
292 internal_strncat(buff, " (", 3);
293 internal_strncat(buff, name, buff_len - 4);
294 internal_strncat(buff, ")", 2);
295 return buff;
296 }
297
ThreadNameWithParenthesis(u32 tid,char buff[],uptr buff_len)298 const char *ThreadNameWithParenthesis(u32 tid, char buff[],
299 uptr buff_len) {
300 if (tid == kInvalidTid) return "";
301 asanThreadRegistry().CheckLocked();
302 AsanThreadContext *t = GetThreadContextByTidLocked(tid);
303 return ThreadNameWithParenthesis(t, buff, buff_len);
304 }
305
PrintAccessAndVarIntersection(const char * var_name,uptr var_beg,uptr var_size,uptr addr,uptr access_size,uptr prev_var_end,uptr next_var_beg)306 void PrintAccessAndVarIntersection(const char *var_name,
307 uptr var_beg, uptr var_size,
308 uptr addr, uptr access_size,
309 uptr prev_var_end, uptr next_var_beg) {
310 uptr var_end = var_beg + var_size;
311 uptr addr_end = addr + access_size;
312 const char *pos_descr = 0;
313 // If the variable [var_beg, var_end) is the nearest variable to the
314 // current memory access, indicate it in the log.
315 if (addr >= var_beg) {
316 if (addr_end <= var_end)
317 pos_descr = "is inside"; // May happen if this is a use-after-return.
318 else if (addr < var_end)
319 pos_descr = "partially overflows";
320 else if (addr_end <= next_var_beg &&
321 next_var_beg - addr_end >= addr - var_end)
322 pos_descr = "overflows";
323 } else {
324 if (addr_end > var_beg)
325 pos_descr = "partially underflows";
326 else if (addr >= prev_var_end &&
327 addr - prev_var_end >= var_beg - addr_end)
328 pos_descr = "underflows";
329 }
330 InternalScopedString str(1024);
331 str.append(" [%zd, %zd) '%s'", var_beg, var_beg + var_size, var_name);
332 if (pos_descr) {
333 Decorator d;
334 // FIXME: we may want to also print the size of the access here,
335 // but in case of accesses generated by memset it may be confusing.
336 str.append("%s <== Memory access at offset %zd %s this variable%s\n",
337 d.Location(), addr, pos_descr, d.EndLocation());
338 } else {
339 str.append("\n");
340 }
341 Printf("%s", str.data());
342 }
343
344 struct StackVarDescr {
345 uptr beg;
346 uptr size;
347 const char *name_pos;
348 uptr name_len;
349 };
350
DescribeAddressIfStack(uptr addr,uptr access_size)351 bool DescribeAddressIfStack(uptr addr, uptr access_size) {
352 AsanThread *t = FindThreadByStackAddress(addr);
353 if (!t) return false;
354 const uptr kBufSize = 4095;
355 char buf[kBufSize];
356 uptr offset = 0;
357 uptr frame_pc = 0;
358 char tname[128];
359 const char *frame_descr = t->GetFrameNameByAddr(addr, &offset, &frame_pc);
360
361 #ifdef __powerpc64__
362 // On PowerPC64, the address of a function actually points to a
363 // three-doubleword data structure with the first field containing
364 // the address of the function's code.
365 frame_pc = *reinterpret_cast<uptr *>(frame_pc);
366 #endif
367
368 // This string is created by the compiler and has the following form:
369 // "n alloc_1 alloc_2 ... alloc_n"
370 // where alloc_i looks like "offset size len ObjectName ".
371 CHECK(frame_descr);
372 Decorator d;
373 Printf("%s", d.Location());
374 Printf("Address %p is located in stack of thread T%d%s "
375 "at offset %zu in frame\n",
376 addr, t->tid(),
377 ThreadNameWithParenthesis(t->tid(), tname, sizeof(tname)),
378 offset);
379 // Now we print the frame where the alloca has happened.
380 // We print this frame as a stack trace with one element.
381 // The symbolizer may print more than one frame if inlining was involved.
382 // The frame numbers may be different than those in the stack trace printed
383 // previously. That's unfortunate, but I have no better solution,
384 // especially given that the alloca may be from entirely different place
385 // (e.g. use-after-scope, or different thread's stack).
386 StackTrace alloca_stack;
387 alloca_stack.trace[0] = frame_pc + 16;
388 alloca_stack.size = 1;
389 Printf("%s", d.EndLocation());
390 alloca_stack.Print();
391 // Report the number of stack objects.
392 char *p;
393 uptr n_objects = (uptr)internal_simple_strtoll(frame_descr, &p, 10);
394 CHECK_GT(n_objects, 0);
395 Printf(" This frame has %zu object(s):\n", n_objects);
396
397 // Report all objects in this frame.
398 InternalScopedBuffer<StackVarDescr> vars(n_objects);
399 for (uptr i = 0; i < n_objects; i++) {
400 uptr beg, size;
401 uptr len;
402 beg = (uptr)internal_simple_strtoll(p, &p, 10);
403 size = (uptr)internal_simple_strtoll(p, &p, 10);
404 len = (uptr)internal_simple_strtoll(p, &p, 10);
405 if (beg == 0 || size == 0 || *p != ' ') {
406 Printf("AddressSanitizer can't parse the stack frame "
407 "descriptor: |%s|\n", frame_descr);
408 break;
409 }
410 p++;
411 vars[i].beg = beg;
412 vars[i].size = size;
413 vars[i].name_pos = p;
414 vars[i].name_len = len;
415 p += len;
416 }
417 for (uptr i = 0; i < n_objects; i++) {
418 buf[0] = 0;
419 internal_strncat(buf, vars[i].name_pos,
420 static_cast<uptr>(Min(kBufSize, vars[i].name_len)));
421 uptr prev_var_end = i ? vars[i - 1].beg + vars[i - 1].size : 0;
422 uptr next_var_beg = i + 1 < n_objects ? vars[i + 1].beg : ~(0UL);
423 PrintAccessAndVarIntersection(buf, vars[i].beg, vars[i].size,
424 offset, access_size,
425 prev_var_end, next_var_beg);
426 }
427 Printf("HINT: this may be a false positive if your program uses "
428 "some custom stack unwind mechanism or swapcontext\n"
429 " (longjmp and C++ exceptions *are* supported)\n");
430 DescribeThread(t);
431 return true;
432 }
433
DescribeAccessToHeapChunk(AsanChunkView chunk,uptr addr,uptr access_size)434 static void DescribeAccessToHeapChunk(AsanChunkView chunk, uptr addr,
435 uptr access_size) {
436 sptr offset;
437 Decorator d;
438 InternalScopedString str(4096);
439 str.append("%s", d.Location());
440 if (chunk.AddrIsAtLeft(addr, access_size, &offset)) {
441 str.append("%p is located %zd bytes to the left of", (void *)addr, offset);
442 } else if (chunk.AddrIsAtRight(addr, access_size, &offset)) {
443 if (offset < 0) {
444 addr -= offset;
445 offset = 0;
446 }
447 str.append("%p is located %zd bytes to the right of", (void *)addr, offset);
448 } else if (chunk.AddrIsInside(addr, access_size, &offset)) {
449 str.append("%p is located %zd bytes inside of", (void*)addr, offset);
450 } else {
451 str.append("%p is located somewhere around (this is AddressSanitizer bug!)",
452 (void *)addr);
453 }
454 str.append(" %zu-byte region [%p,%p)\n", chunk.UsedSize(),
455 (void *)(chunk.Beg()), (void *)(chunk.End()));
456 str.append("%s", d.EndLocation());
457 Printf("%s", str.data());
458 }
459
DescribeHeapAddress(uptr addr,uptr access_size)460 void DescribeHeapAddress(uptr addr, uptr access_size) {
461 AsanChunkView chunk = FindHeapChunkByAddress(addr);
462 if (!chunk.IsValid()) {
463 Printf("AddressSanitizer can not describe address in more detail "
464 "(wild memory access suspected).\n");
465 return;
466 }
467 DescribeAccessToHeapChunk(chunk, addr, access_size);
468 CHECK(chunk.AllocTid() != kInvalidTid);
469 asanThreadRegistry().CheckLocked();
470 AsanThreadContext *alloc_thread =
471 GetThreadContextByTidLocked(chunk.AllocTid());
472 StackTrace alloc_stack;
473 chunk.GetAllocStack(&alloc_stack);
474 char tname[128];
475 Decorator d;
476 AsanThreadContext *free_thread = 0;
477 if (chunk.FreeTid() != kInvalidTid) {
478 free_thread = GetThreadContextByTidLocked(chunk.FreeTid());
479 Printf("%sfreed by thread T%d%s here:%s\n", d.Allocation(),
480 free_thread->tid,
481 ThreadNameWithParenthesis(free_thread, tname, sizeof(tname)),
482 d.EndAllocation());
483 StackTrace free_stack;
484 chunk.GetFreeStack(&free_stack);
485 free_stack.Print();
486 Printf("%spreviously allocated by thread T%d%s here:%s\n",
487 d.Allocation(), alloc_thread->tid,
488 ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
489 d.EndAllocation());
490 } else {
491 Printf("%sallocated by thread T%d%s here:%s\n", d.Allocation(),
492 alloc_thread->tid,
493 ThreadNameWithParenthesis(alloc_thread, tname, sizeof(tname)),
494 d.EndAllocation());
495 }
496 alloc_stack.Print();
497 DescribeThread(GetCurrentThread());
498 if (free_thread)
499 DescribeThread(free_thread);
500 DescribeThread(alloc_thread);
501 }
502
DescribeAddress(uptr addr,uptr access_size)503 void DescribeAddress(uptr addr, uptr access_size) {
504 // Check if this is shadow or shadow gap.
505 if (DescribeAddressIfShadow(addr))
506 return;
507 CHECK(AddrIsInMem(addr));
508 if (DescribeAddressIfGlobal(addr, access_size))
509 return;
510 if (DescribeAddressIfStack(addr, access_size))
511 return;
512 // Assume it is a heap address.
513 DescribeHeapAddress(addr, access_size);
514 }
515
516 // ------------------- Thread description -------------------- {{{1
517
DescribeThread(AsanThreadContext * context)518 void DescribeThread(AsanThreadContext *context) {
519 CHECK(context);
520 asanThreadRegistry().CheckLocked();
521 // No need to announce the main thread.
522 if (context->tid == 0 || context->announced) {
523 return;
524 }
525 context->announced = true;
526 char tname[128];
527 InternalScopedString str(1024);
528 str.append("Thread T%d%s", context->tid,
529 ThreadNameWithParenthesis(context->tid, tname, sizeof(tname)));
530 str.append(
531 " created by T%d%s here:\n", context->parent_tid,
532 ThreadNameWithParenthesis(context->parent_tid, tname, sizeof(tname)));
533 Printf("%s", str.data());
534 uptr stack_size;
535 const uptr *stack_trace = StackDepotGet(context->stack_id, &stack_size);
536 StackTrace::PrintStack(stack_trace, stack_size);
537 // Recursively described parent thread if needed.
538 if (flags()->print_full_thread_history) {
539 AsanThreadContext *parent_context =
540 GetThreadContextByTidLocked(context->parent_tid);
541 DescribeThread(parent_context);
542 }
543 }
544
545 // -------------------- Different kinds of reports ----------------- {{{1
546
547 // Use ScopedInErrorReport to run common actions just before and
548 // immediately after printing error report.
549 class ScopedInErrorReport {
550 public:
ScopedInErrorReport()551 ScopedInErrorReport() {
552 static atomic_uint32_t num_calls;
553 static u32 reporting_thread_tid;
554 if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
555 // Do not print more than one report, otherwise they will mix up.
556 // Error reporting functions shouldn't return at this situation, as
557 // they are defined as no-return.
558 Report("AddressSanitizer: while reporting a bug found another one."
559 "Ignoring.\n");
560 u32 current_tid = GetCurrentTidOrInvalid();
561 if (current_tid != reporting_thread_tid) {
562 // ASan found two bugs in different threads simultaneously. Sleep
563 // long enough to make sure that the thread which started to print
564 // an error report will finish doing it.
565 SleepForSeconds(Max(100, flags()->sleep_before_dying + 1));
566 }
567 // If we're still not dead for some reason, use raw _exit() instead of
568 // Die() to bypass any additional checks.
569 internal__exit(flags()->exitcode);
570 }
571 ASAN_ON_ERROR();
572 // Make sure the registry and sanitizer report mutexes are locked while
573 // we're printing an error report.
574 // We can lock them only here to avoid self-deadlock in case of
575 // recursive reports.
576 asanThreadRegistry().Lock();
577 CommonSanitizerReportMutex.Lock();
578 reporting_thread_tid = GetCurrentTidOrInvalid();
579 Printf("===================================================="
580 "=============\n");
581 }
582 // Destructor is NORETURN, as functions that report errors are.
~ScopedInErrorReport()583 NORETURN ~ScopedInErrorReport() {
584 // Make sure the current thread is announced.
585 DescribeThread(GetCurrentThread());
586 // We may want to grab this lock again when printing stats.
587 asanThreadRegistry().Unlock();
588 // Print memory stats.
589 if (flags()->print_stats)
590 __asan_print_accumulated_stats();
591 if (error_report_callback) {
592 error_report_callback(error_message_buffer);
593 }
594 Report("ABORTING\n");
595 Die();
596 }
597 };
598
ReportStackOverflow(uptr pc,uptr sp,uptr bp,void * context,uptr addr)599 void ReportStackOverflow(uptr pc, uptr sp, uptr bp, void *context, uptr addr) {
600 ScopedInErrorReport in_report;
601 Decorator d;
602 Printf("%s", d.Warning());
603 Report(
604 "ERROR: AddressSanitizer: stack-overflow on address %p"
605 " (pc %p sp %p bp %p T%d)\n",
606 (void *)addr, (void *)pc, (void *)sp, (void *)bp,
607 GetCurrentTidOrInvalid());
608 Printf("%s", d.EndWarning());
609 GET_STACK_TRACE_SIGNAL(pc, bp, context);
610 stack.Print();
611 ReportErrorSummary("stack-overflow", &stack);
612 }
613
ReportSIGSEGV(uptr pc,uptr sp,uptr bp,void * context,uptr addr)614 void ReportSIGSEGV(uptr pc, uptr sp, uptr bp, void *context, uptr addr) {
615 ScopedInErrorReport in_report;
616 Decorator d;
617 Printf("%s", d.Warning());
618 Report(
619 "ERROR: AddressSanitizer: SEGV on unknown address %p"
620 " (pc %p sp %p bp %p T%d)\n",
621 (void *)addr, (void *)pc, (void *)sp, (void *)bp,
622 GetCurrentTidOrInvalid());
623 Printf("%s", d.EndWarning());
624 GET_STACK_TRACE_SIGNAL(pc, bp, context);
625 stack.Print();
626 Printf("AddressSanitizer can not provide additional info.\n");
627 ReportErrorSummary("SEGV", &stack);
628 }
629
ReportDoubleFree(uptr addr,StackTrace * free_stack)630 void ReportDoubleFree(uptr addr, StackTrace *free_stack) {
631 ScopedInErrorReport in_report;
632 Decorator d;
633 Printf("%s", d.Warning());
634 char tname[128];
635 u32 curr_tid = GetCurrentTidOrInvalid();
636 Report("ERROR: AddressSanitizer: attempting double-free on %p in "
637 "thread T%d%s:\n",
638 addr, curr_tid,
639 ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)));
640 Printf("%s", d.EndWarning());
641 CHECK_GT(free_stack->size, 0);
642 GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
643 stack.Print();
644 DescribeHeapAddress(addr, 1);
645 ReportErrorSummary("double-free", &stack);
646 }
647
ReportFreeNotMalloced(uptr addr,StackTrace * free_stack)648 void ReportFreeNotMalloced(uptr addr, StackTrace *free_stack) {
649 ScopedInErrorReport in_report;
650 Decorator d;
651 Printf("%s", d.Warning());
652 char tname[128];
653 u32 curr_tid = GetCurrentTidOrInvalid();
654 Report("ERROR: AddressSanitizer: attempting free on address "
655 "which was not malloc()-ed: %p in thread T%d%s\n", addr,
656 curr_tid, ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)));
657 Printf("%s", d.EndWarning());
658 CHECK_GT(free_stack->size, 0);
659 GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
660 stack.Print();
661 DescribeHeapAddress(addr, 1);
662 ReportErrorSummary("bad-free", &stack);
663 }
664
ReportAllocTypeMismatch(uptr addr,StackTrace * free_stack,AllocType alloc_type,AllocType dealloc_type)665 void ReportAllocTypeMismatch(uptr addr, StackTrace *free_stack,
666 AllocType alloc_type,
667 AllocType dealloc_type) {
668 static const char *alloc_names[] =
669 {"INVALID", "malloc", "operator new", "operator new []"};
670 static const char *dealloc_names[] =
671 {"INVALID", "free", "operator delete", "operator delete []"};
672 CHECK_NE(alloc_type, dealloc_type);
673 ScopedInErrorReport in_report;
674 Decorator d;
675 Printf("%s", d.Warning());
676 Report("ERROR: AddressSanitizer: alloc-dealloc-mismatch (%s vs %s) on %p\n",
677 alloc_names[alloc_type], dealloc_names[dealloc_type], addr);
678 Printf("%s", d.EndWarning());
679 CHECK_GT(free_stack->size, 0);
680 GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
681 stack.Print();
682 DescribeHeapAddress(addr, 1);
683 ReportErrorSummary("alloc-dealloc-mismatch", &stack);
684 Report("HINT: if you don't care about these warnings you may set "
685 "ASAN_OPTIONS=alloc_dealloc_mismatch=0\n");
686 }
687
ReportMallocUsableSizeNotOwned(uptr addr,StackTrace * stack)688 void ReportMallocUsableSizeNotOwned(uptr addr, StackTrace *stack) {
689 ScopedInErrorReport in_report;
690 Decorator d;
691 Printf("%s", d.Warning());
692 Report("ERROR: AddressSanitizer: attempting to call "
693 "malloc_usable_size() for pointer which is "
694 "not owned: %p\n", addr);
695 Printf("%s", d.EndWarning());
696 stack->Print();
697 DescribeHeapAddress(addr, 1);
698 ReportErrorSummary("bad-malloc_usable_size", stack);
699 }
700
ReportSanitizerGetAllocatedSizeNotOwned(uptr addr,StackTrace * stack)701 void ReportSanitizerGetAllocatedSizeNotOwned(uptr addr, StackTrace *stack) {
702 ScopedInErrorReport in_report;
703 Decorator d;
704 Printf("%s", d.Warning());
705 Report("ERROR: AddressSanitizer: attempting to call "
706 "__sanitizer_get_allocated_size() for pointer which is "
707 "not owned: %p\n", addr);
708 Printf("%s", d.EndWarning());
709 stack->Print();
710 DescribeHeapAddress(addr, 1);
711 ReportErrorSummary("bad-__sanitizer_get_allocated_size", stack);
712 }
713
ReportStringFunctionMemoryRangesOverlap(const char * function,const char * offset1,uptr length1,const char * offset2,uptr length2,StackTrace * stack)714 void ReportStringFunctionMemoryRangesOverlap(
715 const char *function, const char *offset1, uptr length1,
716 const char *offset2, uptr length2, StackTrace *stack) {
717 ScopedInErrorReport in_report;
718 Decorator d;
719 char bug_type[100];
720 internal_snprintf(bug_type, sizeof(bug_type), "%s-param-overlap", function);
721 Printf("%s", d.Warning());
722 Report("ERROR: AddressSanitizer: %s: "
723 "memory ranges [%p,%p) and [%p, %p) overlap\n", \
724 bug_type, offset1, offset1 + length1, offset2, offset2 + length2);
725 Printf("%s", d.EndWarning());
726 stack->Print();
727 DescribeAddress((uptr)offset1, length1);
728 DescribeAddress((uptr)offset2, length2);
729 ReportErrorSummary(bug_type, stack);
730 }
731
ReportStringFunctionSizeOverflow(uptr offset,uptr size,StackTrace * stack)732 void ReportStringFunctionSizeOverflow(uptr offset, uptr size,
733 StackTrace *stack) {
734 ScopedInErrorReport in_report;
735 Decorator d;
736 const char *bug_type = "negative-size-param";
737 Printf("%s", d.Warning());
738 Report("ERROR: AddressSanitizer: %s: (size=%zd)\n", bug_type, size);
739 Printf("%s", d.EndWarning());
740 stack->Print();
741 DescribeAddress(offset, size);
742 ReportErrorSummary(bug_type, stack);
743 }
744
ReportBadParamsToAnnotateContiguousContainer(uptr beg,uptr end,uptr old_mid,uptr new_mid,StackTrace * stack)745 void ReportBadParamsToAnnotateContiguousContainer(uptr beg, uptr end,
746 uptr old_mid, uptr new_mid,
747 StackTrace *stack) {
748 ScopedInErrorReport in_report;
749 Report("ERROR: AddressSanitizer: bad parameters to "
750 "__sanitizer_annotate_contiguous_container:\n"
751 " beg : %p\n"
752 " end : %p\n"
753 " old_mid : %p\n"
754 " new_mid : %p\n",
755 beg, end, old_mid, new_mid);
756 stack->Print();
757 ReportErrorSummary("bad-__sanitizer_annotate_contiguous_container", stack);
758 }
759
ReportODRViolation(const __asan_global * g1,u32 stack_id1,const __asan_global * g2,u32 stack_id2)760 void ReportODRViolation(const __asan_global *g1, u32 stack_id1,
761 const __asan_global *g2, u32 stack_id2) {
762 ScopedInErrorReport in_report;
763 Decorator d;
764 Printf("%s", d.Warning());
765 Report("ERROR: AddressSanitizer: odr-violation (%p):\n", g1->beg);
766 Printf("%s", d.EndWarning());
767 InternalScopedString g1_loc(256), g2_loc(256);
768 PrintGlobalLocation(&g1_loc, *g1);
769 PrintGlobalLocation(&g2_loc, *g2);
770 Printf(" [1] size=%zd %s %s\n", g1->size, g1->name, g1_loc.data());
771 Printf(" [2] size=%zd %s %s\n", g2->size, g2->name, g2_loc.data());
772 if (stack_id1 && stack_id2) {
773 Printf("These globals were registered at these points:\n");
774 Printf(" [1]:\n");
775 uptr stack_size;
776 const uptr *stack_trace = StackDepotGet(stack_id1, &stack_size);
777 StackTrace::PrintStack(stack_trace, stack_size);
778 Printf(" [2]:\n");
779 stack_trace = StackDepotGet(stack_id2, &stack_size);
780 StackTrace::PrintStack(stack_trace, stack_size);
781 }
782 Report("HINT: if you don't care about these warnings you may set "
783 "ASAN_OPTIONS=detect_odr_violation=0\n");
784 ReportErrorSummary("odr-violation", g1_loc.data(), 0, g1->name);
785 }
786
787 // ----------------------- CheckForInvalidPointerPair ----------- {{{1
788 static NOINLINE void
ReportInvalidPointerPair(uptr pc,uptr bp,uptr sp,uptr a1,uptr a2)789 ReportInvalidPointerPair(uptr pc, uptr bp, uptr sp, uptr a1, uptr a2) {
790 ScopedInErrorReport in_report;
791 Decorator d;
792 Printf("%s", d.Warning());
793 Report("ERROR: AddressSanitizer: invalid-pointer-pair: %p %p\n", a1, a2);
794 Printf("%s", d.EndWarning());
795 GET_STACK_TRACE_FATAL(pc, bp);
796 stack.Print();
797 DescribeAddress(a1, 1);
798 DescribeAddress(a2, 1);
799 ReportErrorSummary("invalid-pointer-pair", &stack);
800 }
801
CheckForInvalidPointerPair(void * p1,void * p2)802 static INLINE void CheckForInvalidPointerPair(void *p1, void *p2) {
803 if (!flags()->detect_invalid_pointer_pairs) return;
804 uptr a1 = reinterpret_cast<uptr>(p1);
805 uptr a2 = reinterpret_cast<uptr>(p2);
806 AsanChunkView chunk1 = FindHeapChunkByAddress(a1);
807 AsanChunkView chunk2 = FindHeapChunkByAddress(a2);
808 bool valid1 = chunk1.IsValid();
809 bool valid2 = chunk2.IsValid();
810 if ((valid1 != valid2) || (valid1 && valid2 && !chunk1.Eq(chunk2))) {
811 GET_CALLER_PC_BP_SP; \
812 return ReportInvalidPointerPair(pc, bp, sp, a1, a2);
813 }
814 }
815 // ----------------------- Mac-specific reports ----------------- {{{1
816
WarnMacFreeUnallocated(uptr addr,uptr zone_ptr,const char * zone_name,StackTrace * stack)817 void WarnMacFreeUnallocated(
818 uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
819 // Just print a warning here.
820 Printf("free_common(%p) -- attempting to free unallocated memory.\n"
821 "AddressSanitizer is ignoring this error on Mac OS now.\n",
822 addr);
823 PrintZoneForPointer(addr, zone_ptr, zone_name);
824 stack->Print();
825 DescribeHeapAddress(addr, 1);
826 }
827
ReportMacMzReallocUnknown(uptr addr,uptr zone_ptr,const char * zone_name,StackTrace * stack)828 void ReportMacMzReallocUnknown(
829 uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
830 ScopedInErrorReport in_report;
831 Printf("mz_realloc(%p) -- attempting to realloc unallocated memory.\n"
832 "This is an unrecoverable problem, exiting now.\n",
833 addr);
834 PrintZoneForPointer(addr, zone_ptr, zone_name);
835 stack->Print();
836 DescribeHeapAddress(addr, 1);
837 }
838
ReportMacCfReallocUnknown(uptr addr,uptr zone_ptr,const char * zone_name,StackTrace * stack)839 void ReportMacCfReallocUnknown(
840 uptr addr, uptr zone_ptr, const char *zone_name, StackTrace *stack) {
841 ScopedInErrorReport in_report;
842 Printf("cf_realloc(%p) -- attempting to realloc unallocated memory.\n"
843 "This is an unrecoverable problem, exiting now.\n",
844 addr);
845 PrintZoneForPointer(addr, zone_ptr, zone_name);
846 stack->Print();
847 DescribeHeapAddress(addr, 1);
848 }
849
850 } // namespace __asan
851
852 // --------------------------- Interface --------------------- {{{1
853 using namespace __asan; // NOLINT
854
__asan_report_error(uptr pc,uptr bp,uptr sp,uptr addr,int is_write,uptr access_size)855 void __asan_report_error(uptr pc, uptr bp, uptr sp, uptr addr, int is_write,
856 uptr access_size) {
857 ScopedInErrorReport in_report;
858
859 // Determine the error type.
860 const char *bug_descr = "unknown-crash";
861 if (AddrIsInMem(addr)) {
862 u8 *shadow_addr = (u8*)MemToShadow(addr);
863 // If we are accessing 16 bytes, look at the second shadow byte.
864 if (*shadow_addr == 0 && access_size > SHADOW_GRANULARITY)
865 shadow_addr++;
866 // If we are in the partial right redzone, look at the next shadow byte.
867 if (*shadow_addr > 0 && *shadow_addr < 128)
868 shadow_addr++;
869 switch (*shadow_addr) {
870 case kAsanHeapLeftRedzoneMagic:
871 case kAsanHeapRightRedzoneMagic:
872 bug_descr = "heap-buffer-overflow";
873 break;
874 case kAsanHeapFreeMagic:
875 bug_descr = "heap-use-after-free";
876 break;
877 case kAsanStackLeftRedzoneMagic:
878 bug_descr = "stack-buffer-underflow";
879 break;
880 case kAsanInitializationOrderMagic:
881 bug_descr = "initialization-order-fiasco";
882 break;
883 case kAsanStackMidRedzoneMagic:
884 case kAsanStackRightRedzoneMagic:
885 case kAsanStackPartialRedzoneMagic:
886 bug_descr = "stack-buffer-overflow";
887 break;
888 case kAsanStackAfterReturnMagic:
889 bug_descr = "stack-use-after-return";
890 break;
891 case kAsanUserPoisonedMemoryMagic:
892 bug_descr = "use-after-poison";
893 break;
894 case kAsanContiguousContainerOOBMagic:
895 bug_descr = "container-overflow";
896 break;
897 case kAsanStackUseAfterScopeMagic:
898 bug_descr = "stack-use-after-scope";
899 break;
900 case kAsanGlobalRedzoneMagic:
901 bug_descr = "global-buffer-overflow";
902 break;
903 }
904 }
905 Decorator d;
906 Printf("%s", d.Warning());
907 Report("ERROR: AddressSanitizer: %s on address "
908 "%p at pc 0x%zx bp 0x%zx sp 0x%zx\n",
909 bug_descr, (void*)addr, pc, bp, sp);
910 Printf("%s", d.EndWarning());
911
912 u32 curr_tid = GetCurrentTidOrInvalid();
913 char tname[128];
914 Printf("%s%s of size %zu at %p thread T%d%s%s\n",
915 d.Access(),
916 access_size ? (is_write ? "WRITE" : "READ") : "ACCESS",
917 access_size, (void*)addr, curr_tid,
918 ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)),
919 d.EndAccess());
920
921 GET_STACK_TRACE_FATAL(pc, bp);
922 stack.Print();
923
924 DescribeAddress(addr, access_size);
925 ReportErrorSummary(bug_descr, &stack);
926 PrintShadowMemoryForAddress(addr);
927 }
928
__asan_set_error_report_callback(void (* callback)(const char *))929 void NOINLINE __asan_set_error_report_callback(void (*callback)(const char*)) {
930 error_report_callback = callback;
931 if (callback) {
932 error_message_buffer_size = 1 << 16;
933 error_message_buffer =
934 (char*)MmapOrDie(error_message_buffer_size, __func__);
935 error_message_buffer_pos = 0;
936 }
937 }
938
__asan_describe_address(uptr addr)939 void __asan_describe_address(uptr addr) {
940 DescribeAddress(addr, 1);
941 }
942
943 extern "C" {
944 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_ptr_sub(void * a,void * b)945 void __sanitizer_ptr_sub(void *a, void *b) {
946 CheckForInvalidPointerPair(a, b);
947 }
948 SANITIZER_INTERFACE_ATTRIBUTE
__sanitizer_ptr_cmp(void * a,void * b)949 void __sanitizer_ptr_cmp(void *a, void *b) {
950 CheckForInvalidPointerPair(a, b);
951 }
952 } // extern "C"
953
954 #if !SANITIZER_SUPPORTS_WEAK_HOOKS
955 // Provide default implementation of __asan_on_error that does nothing
956 // and may be overriden by user.
957 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE NOINLINE
__asan_on_error()958 void __asan_on_error() {}
959 #endif
960