lib/msan/msan_linux.cc

   1 //===-- msan_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 MemorySanitizer.
  11 //
  12 // Linux-specific code.
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "sanitizer_common/sanitizer_platform.h"
  16 #if SANITIZER_LINUX
  17
  18 #include "msan.h"
  19
  20 #include <elf.h>
  21 #include <link.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <signal.h>
  25 #include <unistd.h>
  26 #include <unwind.h>
  27 #include <execinfo.h>
  28 #include <sys/time.h>
  29 #include <sys/resource.h>
  30
  31 #include "sanitizer_common/sanitizer_common.h"
  32 #include "sanitizer_common/sanitizer_procmaps.h"
  33
  34 namespace __msan {
  35
  36 static const uptr kMemBeg     = 0x600000000000;
  37 static const uptr kMemEnd     = 0x7fffffffffff;
  38 static const uptr kShadowBeg  = MEM_TO_SHADOW(kMemBeg);
  39 static const uptr kShadowEnd  = MEM_TO_SHADOW(kMemEnd);
  40 static const uptr kBad1Beg    = 0x100000000;  // 4G
  41 static const uptr kBad1End    = kShadowBeg - 1;
  42 static const uptr kBad2Beg    = kShadowEnd + 1;
  43 static const uptr kBad2End    = kMemBeg - 1;
  44 static const uptr kOriginsBeg = kBad2Beg;
  45 static const uptr kOriginsEnd = kBad2End;
  46
  47 bool InitShadow(bool prot1, bool prot2, bool map_shadow, bool init_origins) {
  48   if (common_flags()->verbosity) {
  49     Printf("__msan_init %p\n", &__msan_init);
  50     Printf("Memory   : %p %p\n", kMemBeg, kMemEnd);
  51     Printf("Bad2     : %p %p\n", kBad2Beg, kBad2End);
  52     Printf("Origins  : %p %p\n", kOriginsBeg, kOriginsEnd);
  53     Printf("Shadow   : %p %p\n", kShadowBeg, kShadowEnd);
  54     Printf("Bad1     : %p %p\n", kBad1Beg, kBad1End);
  55   }
  56
  57   if (!MemoryRangeIsAvailable(kShadowBeg,
  58                               init_origins ? kOriginsEnd : kShadowEnd)) {
  59     Printf("FATAL: Shadow memory range is not available.\n");
  60     return false;
  61   }
  62
  63   if (prot1 && !Mprotect(kBad1Beg, kBad1End - kBad1Beg))
  64     return false;
  65   if (prot2 && !Mprotect(kBad2Beg, kBad2End - kBad2Beg))
  66     return false;
  67   if (map_shadow) {
  68     void *shadow = MmapFixedNoReserve(kShadowBeg, kShadowEnd - kShadowBeg);
  69     if (shadow != (void*)kShadowBeg) return false;
  70   }
  71   if (init_origins) {
  72     void *origins = MmapFixedNoReserve(kOriginsBeg, kOriginsEnd - kOriginsBeg);
  73     if (origins != (void*)kOriginsBeg) return false;
  74   }
  75   return true;
  76 }
  77
  78 void MsanDie() {
  79   _exit(flags()->exit_code);
  80 }
  81
  82 static void MsanAtExit(void) {
  83   if (msan_report_count > 0) {
  84     ReportAtExitStatistics();
  85     if (flags()->exit_code)
  86       _exit(flags()->exit_code);
  87   }
  88 }
  89
  90 void InstallAtExitHandler() {
  91   atexit(MsanAtExit);
  92 }
  93
  94 }  // namespace __msan
  95
  96 #endif  // __linux__