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_POSIX
  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_posix.h"
  23 #include "sanitizer_common/sanitizer_procmaps.h"
  24
  25 #include <pthread.h>
  26 #include <signal.h>
  27 #include <stdlib.h>
  28 #include <sys/time.h>
  29 #include <sys/resource.h>
  30 #include <unistd.h>
  31
  32 namespace __asan {
  33
  34 void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
  35   ScopedDeadlySignal signal_scope(GetCurrentThread());
  36   int code = (int)((siginfo_t*)siginfo)->si_code;
  37   // Write the first message using the bullet-proof write.
  38   if (18 != internal_write(2, "ASAN:DEADLYSIGNAL\n", 18)) Die();
  39   SignalContext sig = SignalContext::Create(siginfo, context);
  40
  41   // Access at a reasonable offset above SP, or slightly below it (to account
  42   // for x86_64 or PowerPC redzone, ARM push of multiple registers, etc) is
  43   // probably a stack overflow.
  44   bool IsStackAccess = sig.addr + 512 > sig.sp && sig.addr < sig.sp + 0xFFFF;
  45
  46 #if __powerpc__
  47   // Large stack frames can be allocated with e.g.
  48   //   lis r0,-10000
  49   //   stdux r1,r1,r0 # store sp to [sp-10000] and update sp by -10000
  50   // If the store faults then sp will not have been updated, so test above
  51   // will not work, becase the fault address will be more than just "slightly"
  52   // below sp.
  53   if (!IsStackAccess && IsAccessibleMemoryRange(sig.pc, 4)) {
  54     u32 inst = *(unsigned *)sig.pc;
  55     u32 ra = (inst >> 16) & 0x1F;
  56     u32 opcd = inst >> 26;
  57     u32 xo = (inst >> 1) & 0x3FF;
  58     // Check for store-with-update to sp. The instructions we accept are:
  59     //   stbu rs,d(ra)          stbux rs,ra,rb
  60     //   sthu rs,d(ra)          sthux rs,ra,rb
  61     //   stwu rs,d(ra)          stwux rs,ra,rb
  62     //   stdu rs,ds(ra)         stdux rs,ra,rb
  63     // where ra is r1 (the stack pointer).
  64     if (ra == 1 &&
  65         (opcd == 39 || opcd == 45 || opcd == 37 || opcd == 62 ||
  66          (opcd == 31 && (xo == 247 || xo == 439 || xo == 183 || xo == 181))))
  67       IsStackAccess = true;
  68   }
  69 #endif // __powerpc__
  70
  71   // We also check si_code to filter out SEGV caused by something else other
  72   // then hitting the guard page or unmapped memory, like, for example,
  73   // unaligned memory access.
  74   if (IsStackAccess && (code == si_SEGV_MAPERR || code == si_SEGV_ACCERR))
  75     ReportStackOverflow(sig);
  76   else if (signo == SIGFPE)
  77     ReportDeadlySignal("FPE", sig);
  78   else
  79     ReportDeadlySignal("SEGV", sig);
  80 }
  81
  82 // ---------------------- TSD ---------------- {{{1
  83
  84 static pthread_key_t tsd_key;
  85 static bool tsd_key_inited = false;
  86 void AsanTSDInit(void (*destructor)(void *tsd)) {
  87   CHECK(!tsd_key_inited);
  88   tsd_key_inited = true;
  89   CHECK_EQ(0, pthread_key_create(&tsd_key, destructor));
  90 }
  91
  92 void *AsanTSDGet() {
  93   CHECK(tsd_key_inited);
  94   return pthread_getspecific(tsd_key);
  95 }
  96
  97 void AsanTSDSet(void *tsd) {
  98   CHECK(tsd_key_inited);
  99   pthread_setspecific(tsd_key, tsd);
 100 }
 101
 102 void PlatformTSDDtor(void *tsd) {
 103   AsanThreadContext *context = (AsanThreadContext*)tsd;
 104   if (context->destructor_iterations > 1) {
 105     context->destructor_iterations--;
 106     CHECK_EQ(0, pthread_setspecific(tsd_key, tsd));
 107     return;
 108   }
 109   AsanThread::TSDDtor(tsd);
 110 }
 111 }  // namespace __asan
 112
 113 #endif  // SANITIZER_POSIX