src/compiler-rt/lib/asan/asan_posix.cc

   1 //===-- asan_posix.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
  15 #include "sanitizer_common/sanitizer_platform.h"
  16 #if SANITIZER_POSIX
  17
  18 #include "asan_internal.h"
  19 #include "asan_interceptors.h"
  20 #include "asan_mapping.h"
  21 #include "asan_report.h"
  22 #include "asan_stack.h"
  23 #include "sanitizer_common/sanitizer_libc.h"
  24 #include "sanitizer_common/sanitizer_posix.h"
  25 #include "sanitizer_common/sanitizer_procmaps.h"
  26
  27 #include <pthread.h>
  28 #include <signal.h>
  29 #include <stdlib.h>
  30 #include <sys/time.h>
  31 #include <sys/resource.h>
  32 #include <unistd.h>
  33
  34 namespace __asan {
  35
  36 void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
  37   ScopedDeadlySignal signal_scope(GetCurrentThread());
  38   int code = (int)((siginfo_t*)siginfo)->si_code;
  39   // Write the first message using the bullet-proof write.
  40   if (18 != internal_write(2, "ASAN:DEADLYSIGNAL\n", 18)) Die();
  41   SignalContext sig = SignalContext::Create(siginfo, context);
  42
  43   // Access at a reasonable offset above SP, or slightly below it (to account
  44   // for x86_64 or PowerPC redzone, ARM push of multiple registers, etc) is
  45   // probably a stack overflow.
  46   bool IsStackAccess = sig.addr + 512 > sig.sp && sig.addr < sig.sp + 0xFFFF;
  47
  48 #if __powerpc__
  49   // Large stack frames can be allocated with e.g.
  50   //   lis r0,-10000
  51   //   stdux r1,r1,r0 # store sp to [sp-10000] and update sp by -10000
  52   // If the store faults then sp will not have been updated, so test above
  53   // will not work, becase the fault address will be more than just "slightly"
  54   // below sp.
  55   if (!IsStackAccess && IsAccessibleMemoryRange(sig.pc, 4)) {
  56     u32 inst = *(unsigned *)sig.pc;
  57     u32 ra = (inst >> 16) & 0x1F;
  58     u32 opcd = inst >> 26;
  59     u32 xo = (inst >> 1) & 0x3FF;
  60     // Check for store-with-update to sp. The instructions we accept are:
  61     //   stbu rs,d(ra)          stbux rs,ra,rb
  62     //   sthu rs,d(ra)          sthux rs,ra,rb
  63     //   stwu rs,d(ra)          stwux rs,ra,rb
  64     //   stdu rs,ds(ra)         stdux rs,ra,rb
  65     // where ra is r1 (the stack pointer).
  66     if (ra == 1 &&
  67         (opcd == 39 || opcd == 45 || opcd == 37 || opcd == 62 ||
  68          (opcd == 31 && (xo == 247 || xo == 439 || xo == 183 || xo == 181))))
  69       IsStackAccess = true;
  70   }
  71 #endif // __powerpc__
  72
  73   // We also check si_code to filter out SEGV caused by something else other
  74   // then hitting the guard page or unmapped memory, like, for example,
  75   // unaligned memory access.
  76   if (IsStackAccess && (code == si_SEGV_MAPERR || code == si_SEGV_ACCERR))
  77     ReportStackOverflow(sig);
  78   else if (signo == SIGFPE)
  79     ReportDeadlySignal("FPE", sig);
  80   else
  81     ReportDeadlySignal("SEGV", sig);
  82 }
  83
  84 // ---------------------- TSD ---------------- {{{1
  85
  86 static pthread_key_t tsd_key;
  87 static bool tsd_key_inited = false;
  88 void AsanTSDInit(void (*destructor)(void *tsd)) {
  89   CHECK(!tsd_key_inited);
  90   tsd_key_inited = true;
  91   CHECK_EQ(0, pthread_key_create(&tsd_key, destructor));
  92 }
  93
  94 void *AsanTSDGet() {
  95   CHECK(tsd_key_inited);
  96   return pthread_getspecific(tsd_key);
  97 }
  98
  99 void AsanTSDSet(void *tsd) {
 100   CHECK(tsd_key_inited);
 101   pthread_setspecific(tsd_key, tsd);
 102 }
 103
 104 void PlatformTSDDtor(void *tsd) {
 105   AsanThreadContext *context = (AsanThreadContext*)tsd;
 106   if (context->destructor_iterations > 1) {
 107     context->destructor_iterations--;
 108     CHECK_EQ(0, pthread_setspecific(tsd_key, tsd));
 109     return;
 110   }
 111   AsanThread::TSDDtor(tsd);
 112 }
 113 }  // namespace __asan
 114
 115 #endif  // SANITIZER_POSIX