asan_posix.cc revision cb8c4dce691097718d5af41b36899b72ef4b1d84 
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_mapping.h"
19#include "asan_stack.h"
20#include "asan_thread_registry.h"
21#include "sanitizer_common/sanitizer_libc.h"
22#include "sanitizer_common/sanitizer_procmaps.h"
23
24#include <pthread.h>
25#include <signal.h>
26#include <stdlib.h>
27#include <sys/time.h>
28#include <sys/resource.h>
29#include <unistd.h>
30
31static const uptr kAltStackSize = SIGSTKSZ * 4;  // SIGSTKSZ is not enough.
32
33namespace __asan {
34
35static void MaybeInstallSigaction(int signum,
36                                  void (*handler)(int, siginfo_t *, void *)) {
37  if (!AsanInterceptsSignal(signum))
38    return;
39  struct sigaction sigact;
40  REAL(memset)(&sigact, 0, sizeof(sigact));
41  sigact.sa_sigaction = handler;
42  sigact.sa_flags = SA_SIGINFO;
43  if (flags()->use_sigaltstack) sigact.sa_flags |= SA_ONSTACK;
44  CHECK(0 == REAL(sigaction)(signum, &sigact, 0));
45  if (flags()->verbosity >= 1) {
46    Report("Installed the sigaction for signal %d\n", signum);
47  }
48}
49
50static void     ASAN_OnSIGSEGV(int, siginfo_t *siginfo, void *context) {
51  uptr addr = (uptr)siginfo->si_addr;
52  // Write the first message using the bullet-proof write.
53  if (13 != internal_write(2, "ASAN:SIGSEGV\n", 13)) Die();
54  uptr pc, sp, bp;
55  GetPcSpBp(context, &pc, &sp, &bp);
56  AsanReport("ERROR: AddressSanitizer crashed on unknown address %p"
57             " (pc %p sp %p bp %p T%d)\n",
58             (void*)addr, (void*)pc, (void*)sp, (void*)bp,
59             asanThreadRegistry().GetCurrentTidOrInvalid());
60  AsanPrintf("AddressSanitizer can not provide additional info. ABORTING\n");
61  GET_STACK_TRACE_WITH_PC_AND_BP(kStackTraceMax, pc, bp);
62  stack.PrintStack();
63  ShowStatsAndAbort();
64}
65
66void SetAlternateSignalStack() {
67  stack_t altstack, oldstack;
68  CHECK(0 == sigaltstack(0, &oldstack));
69  // If the alternate stack is already in place, do nothing.
70  if ((oldstack.ss_flags & SS_DISABLE) == 0) return;
71  // TODO(glider): the mapped stack should have the MAP_STACK flag in the
72  // future. It is not required by man 2 sigaltstack now (they're using
73  // malloc()).
74  void* base = MmapOrDie(kAltStackSize, __FUNCTION__);
75  altstack.ss_sp = base;
76  altstack.ss_flags = 0;
77  altstack.ss_size = kAltStackSize;
78  CHECK(0 == sigaltstack(&altstack, 0));
79  if (flags()->verbosity > 0) {
80    Report("Alternative stack for T%d set: [%p,%p)\n",
81           asanThreadRegistry().GetCurrentTidOrInvalid(),
82           altstack.ss_sp, (char*)altstack.ss_sp + altstack.ss_size);
83  }
84}
85
86void UnsetAlternateSignalStack() {
87  stack_t altstack, oldstack;
88  altstack.ss_sp = 0;
89  altstack.ss_flags = SS_DISABLE;
90  altstack.ss_size = 0;
91  CHECK(0 == sigaltstack(&altstack, &oldstack));
92  UnmapOrDie(oldstack.ss_sp, oldstack.ss_size);
93}
94
95void InstallSignalHandlers() {
96  // Set the alternate signal stack for the main thread.
97  // This will cause SetAlternateSignalStack to be called twice, but the stack
98  // will be actually set only once.
99  if (flags()->use_sigaltstack) SetAlternateSignalStack();
100  MaybeInstallSigaction(SIGSEGV, ASAN_OnSIGSEGV);
101  MaybeInstallSigaction(SIGBUS, ASAN_OnSIGSEGV);
102}
103
104// ---------------------- TSD ---------------- {{{1
105
106static pthread_key_t tsd_key;
107static bool tsd_key_inited = false;
108void AsanTSDInit(void (*destructor)(void *tsd)) {
109  CHECK(!tsd_key_inited);
110  tsd_key_inited = true;
111  CHECK(0 == pthread_key_create(&tsd_key, destructor));
112}
113
114void *AsanTSDGet() {
115  CHECK(tsd_key_inited);
116  return pthread_getspecific(tsd_key);
117}
118
119void AsanTSDSet(void *tsd) {
120  CHECK(tsd_key_inited);
121  pthread_setspecific(tsd_key, tsd);
122}
123
124}  // namespace __asan
125
126#endif  // __linux__ || __APPLE_
127