libsanitizer/asan/asan_posix.cc

   1 //===-- asan_posix.cc -----------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of AddressSanitizer, an address sanity checker.
   9 //
  10 // Posix-specific details.
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "sanitizer_common/sanitizer_platform.h"
  14 #if SANITIZER_LINUX || SANITIZER_MAC
  15
  16 #include "asan_internal.h"
  17 #include "asan_interceptors.h"
  18 #include "asan_mapping.h"
  19 #include "asan_report.h"
  20 #include "asan_stack.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
  31 static const uptr kAltStackSize = SIGSTKSZ * 4;  // SIGSTKSZ is not enough.
  32
  33 namespace __asan {
  34
  35 static 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_EQ(0, REAL(sigaction)(signum, &sigact, 0));
  45   if (common_flags()->verbosity >= 1) {
  46     Report("Installed the sigaction for signal %d\n", signum);
  47   }
  48 }
  49
  50 static 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   ReportSIGSEGV(pc, sp, bp, addr);
  57 }
  58
  59 void SetAlternateSignalStack() {
  60   stack_t altstack, oldstack;
  61   CHECK_EQ(0, sigaltstack(0, &oldstack));
  62   // If the alternate stack is already in place, do nothing.
  63   if ((oldstack.ss_flags & SS_DISABLE) == 0) return;
  64   // TODO(glider): the mapped stack should have the MAP_STACK flag in the
  65   // future. It is not required by man 2 sigaltstack now (they're using
  66   // malloc()).
  67   void* base = MmapOrDie(kAltStackSize, __FUNCTION__);
  68   altstack.ss_sp = base;
  69   altstack.ss_flags = 0;
  70   altstack.ss_size = kAltStackSize;
  71   CHECK_EQ(0, sigaltstack(&altstack, 0));
  72   if (common_flags()->verbosity > 0) {
  73     Report("Alternative stack for T%d set: [%p,%p)\n",
  74            GetCurrentTidOrInvalid(),
  75            altstack.ss_sp, (char*)altstack.ss_sp + altstack.ss_size);
  76   }
  77 }
  78
  79 void UnsetAlternateSignalStack() {
  80   stack_t altstack, oldstack;
  81   altstack.ss_sp = 0;
  82   altstack.ss_flags = SS_DISABLE;
  83   altstack.ss_size = 0;
  84   CHECK_EQ(0, sigaltstack(&altstack, &oldstack));
  85   UnmapOrDie(oldstack.ss_sp, oldstack.ss_size);
  86 }
  87
  88 void InstallSignalHandlers() {
  89   // Set the alternate signal stack for the main thread.
  90   // This will cause SetAlternateSignalStack to be called twice, but the stack
  91   // will be actually set only once.
  92   if (flags()->use_sigaltstack) SetAlternateSignalStack();
  93   MaybeInstallSigaction(SIGSEGV, ASAN_OnSIGSEGV);
  94   MaybeInstallSigaction(SIGBUS, ASAN_OnSIGSEGV);
  95 }
  96
  97 // ---------------------- TSD ---------------- {{{1
  98
  99 static pthread_key_t tsd_key;
 100 static bool tsd_key_inited = false;
 101 void AsanTSDInit(void (*destructor)(void *tsd)) {
 102   CHECK(!tsd_key_inited);
 103   tsd_key_inited = true;
 104   CHECK_EQ(0, pthread_key_create(&tsd_key, destructor));
 105 }
 106
 107 void *AsanTSDGet() {
 108   CHECK(tsd_key_inited);
 109   return pthread_getspecific(tsd_key);
 110 }
 111
 112 void AsanTSDSet(void *tsd) {
 113   CHECK(tsd_key_inited);
 114   pthread_setspecific(tsd_key, tsd);
 115 }
 116
 117 void PlatformTSDDtor(void *tsd) {
 118   AsanThreadContext *context = (AsanThreadContext*)tsd;
 119   if (context->destructor_iterations > 1) {
 120     context->destructor_iterations--;
 121     CHECK_EQ(0, pthread_setspecific(tsd_key, tsd));
 122     return;
 123   }
 124   AsanThread::TSDDtor(tsd);
 125 }
 126 }  // namespace __asan
 127
 128 #endif  // SANITIZER_LINUX || SANITIZER_MAC