asan_report.cc revision e4bfca2b154a6ab4eda921aff454035f33f3551a 
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_internal.h"
15#include "asan_mapping.h"
16#include "asan_report.h"
17#include "asan_stack.h"
18#include "asan_thread.h"
19#include "asan_thread_registry.h"
20
21namespace __asan {
22
23// ---------------------- Address Descriptions ------------------- {{{1
24
25static bool IsASCII(unsigned char c) {
26  return 0x00 <= c && c <= 0x7F;
27}
28
29// Check if the global is a zero-terminated ASCII string. If so, print it.
30static void PrintGlobalNameIfASCII(const __asan_global &g) {
31  for (uptr p = g.beg; p < g.beg + g.size - 1; p++) {
32    if (!IsASCII(*(unsigned char*)p)) return;
33  }
34  if (*(char*)(g.beg + g.size - 1) != 0) return;
35  AsanPrintf("  '%s' is ascii string '%s'\n", g.name, (char*)g.beg);
36}
37
38bool DescribeAddressRelativeToGlobal(uptr addr, const __asan_global &g) {
39  if (addr < g.beg - kGlobalAndStackRedzone) return false;
40  if (addr >= g.beg + g.size_with_redzone) return false;
41  AsanPrintf("%p is located ", (void*)addr);
42  if (addr < g.beg) {
43    AsanPrintf("%zd bytes to the left", g.beg - addr);
44  } else if (addr >= g.beg + g.size) {
45    AsanPrintf("%zd bytes to the right", addr - (g.beg + g.size));
46  } else {
47    AsanPrintf("%zd bytes inside", addr - g.beg);  // Can it happen?
48  }
49  AsanPrintf(" of global variable '%s' (0x%zx) of size %zu\n",
50             g.name, g.beg, g.size);
51  PrintGlobalNameIfASCII(g);
52  return true;
53}
54
55bool DescribeAddressIfShadow(uptr addr) {
56  if (AddrIsInMem(addr))
57    return false;
58  static const char kAddrInShadowReport[] =
59      "Address %p is located in the %s.\n";
60  if (AddrIsInShadowGap(addr)) {
61    AsanPrintf(kAddrInShadowReport, addr, "shadow gap area");
62    return true;
63  }
64  if (AddrIsInHighShadow(addr)) {
65    AsanPrintf(kAddrInShadowReport, addr, "high shadow area");
66    return true;
67  }
68  if (AddrIsInLowShadow(addr)) {
69    AsanPrintf(kAddrInShadowReport, addr, "low shadow area");
70    return true;
71  }
72  CHECK(0 && "Address is not in memory and not in shadow?");
73  return false;
74}
75
76bool DescribeAddressIfStack(uptr addr, uptr access_size) {
77  AsanThread *t = asanThreadRegistry().FindThreadByStackAddress(addr);
78  if (!t) return false;
79  const sptr kBufSize = 4095;
80  char buf[kBufSize];
81  uptr offset = 0;
82  const char *frame_descr = t->GetFrameNameByAddr(addr, &offset);
83  // This string is created by the compiler and has the following form:
84  // "FunctioName n alloc_1 alloc_2 ... alloc_n"
85  // where alloc_i looks like "offset size len ObjectName ".
86  CHECK(frame_descr);
87  // Report the function name and the offset.
88  const char *name_end = internal_strchr(frame_descr, ' ');
89  CHECK(name_end);
90  buf[0] = 0;
91  internal_strncat(buf, frame_descr,
92                   Min(kBufSize,
93                       static_cast<sptr>(name_end - frame_descr)));
94  AsanPrintf("Address %p is located at offset %zu "
95             "in frame <%s> of T%d's stack:\n",
96             (void*)addr, offset, buf, t->tid());
97  // Report the number of stack objects.
98  char *p;
99  uptr n_objects = internal_simple_strtoll(name_end, &p, 10);
100  CHECK(n_objects > 0);
101  AsanPrintf("  This frame has %zu object(s):\n", n_objects);
102  // Report all objects in this frame.
103  for (uptr i = 0; i < n_objects; i++) {
104    uptr beg, size;
105    sptr len;
106    beg  = internal_simple_strtoll(p, &p, 10);
107    size = internal_simple_strtoll(p, &p, 10);
108    len  = internal_simple_strtoll(p, &p, 10);
109    if (beg <= 0 || size <= 0 || len < 0 || *p != ' ') {
110      AsanPrintf("AddressSanitizer can't parse the stack frame "
111                 "descriptor: |%s|\n", frame_descr);
112      break;
113    }
114    p++;
115    buf[0] = 0;
116    internal_strncat(buf, p, Min(kBufSize, len));
117    p += len;
118    AsanPrintf("    [%zu, %zu) '%s'\n", beg, beg + size, buf);
119  }
120  AsanPrintf("HINT: this may be a false positive if your program uses "
121             "some custom stack unwind mechanism\n"
122             "      (longjmp and C++ exceptions *are* supported)\n");
123  t->summary()->Announce();
124  return true;
125}
126
127void DescribeAddress(uptr addr, uptr access_size) {
128  // Check if this is shadow or shadow gap.
129  if (DescribeAddressIfShadow(addr))
130    return;
131  CHECK(AddrIsInMem(addr));
132  if (DescribeAddressIfGlobal(addr))
133    return;
134  if (DescribeAddressIfStack(addr, access_size))
135    return;
136  // Assume it is a heap address.
137  DescribeHeapAddress(addr, access_size);
138}
139
140// -------------------- Different kinds of reports ----------------- {{{1
141
142void ReportSIGSEGV(uptr pc, uptr sp, uptr bp, uptr addr) {
143  AsanReport("ERROR: AddressSanitizer crashed on unknown address %p"
144             " (pc %p sp %p bp %p T%d)\n",
145             (void*)addr, (void*)pc, (void*)sp, (void*)bp,
146             asanThreadRegistry().GetCurrentTidOrInvalid());
147  AsanPrintf("AddressSanitizer can not provide additional info. ABORTING\n");
148  GET_STACK_TRACE_WITH_PC_AND_BP(kStackTraceMax, pc, bp);
149  stack.PrintStack();
150  ShowStatsAndAbort();
151}
152
153void ReportDoubleFree(uptr addr, AsanStackTrace *stack) {
154  AsanReport("ERROR: AddressSanitizer attempting double-free on %p:\n", addr);
155  stack->PrintStack();
156  DescribeHeapAddress(addr, 1);
157  ShowStatsAndAbort();
158}
159
160void ReportFreeNotMalloced(uptr addr, AsanStackTrace *stack) {
161  AsanReport("ERROR: AddressSanitizer attempting free on address "
162             "which was not malloc()-ed: %p\n", addr);
163  stack->PrintStack();
164  ShowStatsAndAbort();
165}
166
167void ReportMallocUsableSizeNotOwned(uptr addr, AsanStackTrace *stack) {
168  AsanReport("ERROR: AddressSanitizer attempting to call "
169             "malloc_usable_size() for pointer which is "
170             "not owned: %p\n", addr);
171  stack->PrintStack();
172  DescribeHeapAddress(addr, 1);
173  ShowStatsAndAbort();
174}
175
176void ReportAsanGetAllocatedSizeNotOwned(uptr addr, AsanStackTrace *stack) {
177  AsanReport("ERROR: AddressSanitizer attempting to call "
178             "__asan_get_allocated_size() for pointer which is "
179             "not owned: %p\n", addr);
180  stack->PrintStack();
181  DescribeHeapAddress(addr, 1);
182  ShowStatsAndAbort();
183}
184
185void ReportStringFunctionMemoryRangesOverlap(
186    const char *function, const char *offset1, uptr length1,
187    const char *offset2, uptr length2, AsanStackTrace *stack) {
188  AsanReport("ERROR: AddressSanitizer %s-param-overlap: "
189             "memory ranges [%p,%p) and [%p, %p) overlap\n", \
190             function, offset1, offset1 + length1, offset2, offset2 + length2);
191  stack->PrintStack();
192  ShowStatsAndAbort();
193}
194
195}  // namespace __asan
196