asan_posix.cc revision f03d8afc8b8dd072c4e2884a7475ee28ac5f3f41 
1//===-- asan_linux.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// Posix-specific details.
13//===----------------------------------------------------------------------===//
14#if defined(__linux__) || defined(__APPLE__)
15
16#include "asan_internal.h"
17#include "asan_interceptors.h"
18#include "asan_procmaps.h"
19#include "asan_stack.h"
20#include "asan_thread_registry.h"
21
22#include <pthread.h>
23#include <signal.h>
24#include <stdlib.h>
25#include <sys/time.h>
26#include <sys/resource.h>
27#include <unistd.h>
28
29#ifdef ANDROID
30#include <sys/atomics.h>
31#endif
32
33// Should not add dependency on libstdc++,
34// since most of the stuff here is inlinable.
35#include <algorithm>
36
37static const size_t kAltStackSize = SIGSTKSZ * 4;  // SIGSTKSZ is not enough.
38
39namespace __asan {
40
41static void MaybeInstallSigaction(int signum,
42                                  void (*handler)(int, siginfo_t *, void *)) {
43  if (!AsanInterceptsSignal(signum))
44    return;
45  struct sigaction sigact;
46  REAL(memset)(&sigact, 0, sizeof(sigact));
47  sigact.sa_sigaction = handler;
48  sigact.sa_flags = SA_SIGINFO;
49  if (FLAG_use_sigaltstack) sigact.sa_flags |= SA_ONSTACK;
50  CHECK(0 == REAL(sigaction)(signum, &sigact, 0));
51}
52
53static void     ASAN_OnSIGSEGV(int, siginfo_t *siginfo, void *context) {
54  uintptr_t addr = (uintptr_t)siginfo->si_addr;
55  // Write the first message using the bullet-proof write.
56  if (13 != AsanWrite(2, "ASAN:SIGSEGV\n", 13)) AsanDie();
57  uintptr_t pc, sp, bp;
58  GetPcSpBp(context, &pc, &sp, &bp);
59  Report("ERROR: AddressSanitizer crashed on unknown address %p"
60         " (pc %p sp %p bp %p T%d)\n",
61         addr, pc, sp, bp,
62         asanThreadRegistry().GetCurrentTidOrMinusOne());
63  Printf("AddressSanitizer can not provide additional info. ABORTING\n");
64  GET_STACK_TRACE_WITH_PC_AND_BP(kStackTraceMax, pc, bp);
65  stack.PrintStack();
66  ShowStatsAndAbort();
67}
68
69void SetAlternateSignalStack() {
70  stack_t altstack, oldstack;
71  CHECK(0 == sigaltstack(NULL, &oldstack));
72  // If the alternate stack is already in place, do nothing.
73  if ((oldstack.ss_flags & SS_DISABLE) == 0) return;
74  // TODO(glider): the mapped stack should have the MAP_STACK flag in the
75  // future. It is not required by man 2 sigaltstack now (they're using
76  // malloc()).
77  void* base = AsanMmapSomewhereOrDie(kAltStackSize, __FUNCTION__);
78  altstack.ss_sp = base;
79  altstack.ss_flags = 0;
80  altstack.ss_size = kAltStackSize;
81  CHECK(0 == sigaltstack(&altstack, NULL));
82  if (FLAG_v > 0) {
83    Report("Alternative stack for T%d set: [%p,%p)\n",
84           asanThreadRegistry().GetCurrentTidOrMinusOne(),
85           altstack.ss_sp, (char*)altstack.ss_sp + altstack.ss_size);
86  }
87}
88
89void UnsetAlternateSignalStack() {
90  stack_t altstack, oldstack;
91  altstack.ss_sp = NULL;
92  altstack.ss_flags = SS_DISABLE;
93  altstack.ss_size = 0;
94  CHECK(0 == sigaltstack(&altstack, &oldstack));
95  AsanUnmapOrDie(oldstack.ss_sp, oldstack.ss_size);
96}
97
98void InstallSignalHandlers() {
99  // Set the alternate signal stack for the main thread.
100  // This will cause SetAlternateSignalStack to be called twice, but the stack
101  // will be actually set only once.
102  if (FLAG_use_sigaltstack) SetAlternateSignalStack();
103  MaybeInstallSigaction(SIGSEGV, ASAN_OnSIGSEGV);
104  MaybeInstallSigaction(SIGBUS, ASAN_OnSIGSEGV);
105}
106
107void AsanDisableCoreDumper() {
108  struct rlimit nocore;
109  nocore.rlim_cur = 0;
110  nocore.rlim_max = 0;
111  setrlimit(RLIMIT_CORE, &nocore);
112}
113
114void AsanDumpProcessMap() {
115  AsanProcMaps proc_maps;
116  uintptr_t start, end;
117  const intptr_t kBufSize = 4095;
118  char filename[kBufSize];
119  Report("Process memory map follows:\n");
120  while (proc_maps.Next(&start, &end, /* file_offset */NULL,
121                        filename, kBufSize)) {
122    Printf("\t%p-%p\t%s\n", (void*)start, (void*)end, filename);
123  }
124  Report("End of process memory map.\n");
125}
126
127int GetPid() {
128  return getpid();
129}
130
131uintptr_t GetThreadSelf() {
132  return (uintptr_t)pthread_self();
133}
134
135void SleepForSeconds(int seconds) {
136  sleep(seconds);
137}
138
139void Exit(int exitcode) {
140  _exit(exitcode);
141}
142
143int Atexit(void (*function)(void)) {
144  return atexit(function);
145}
146
147int AtomicInc(int *a) {
148#ifdef ANDROID
149  return __atomic_inc(a) + 1;
150#else
151  return __sync_add_and_fetch(a, 1);
152#endif
153}
154
155void SortArray(uintptr_t *array, size_t size) {
156  std::sort(array, array + size);
157}
158
159// ---------------------- TSD ---------------- {{{1
160
161static pthread_key_t tsd_key;
162static bool tsd_key_inited = false;
163void AsanTSDInit(void (*destructor)(void *tsd)) {
164  CHECK(!tsd_key_inited);
165  tsd_key_inited = true;
166  CHECK(0 == pthread_key_create(&tsd_key, destructor));
167}
168
169void *AsanTSDGet() {
170  CHECK(tsd_key_inited);
171  return pthread_getspecific(tsd_key);
172}
173
174void AsanTSDSet(void *tsd) {
175  CHECK(tsd_key_inited);
176  pthread_setspecific(tsd_key, tsd);
177}
178
179}  // namespace __asan
180
181#endif  // __linux__ || __APPLE_
182