libsanitizer/tsan/tsan_platform_posix.cc

   1 //===-- tsan_platform_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 ThreadSanitizer (TSan), a race detector.
   9 //
  10 // POSIX-specific code.
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "sanitizer_common/sanitizer_platform.h"
  14 #if SANITIZER_POSIX
  15
  16 #include "sanitizer_common/sanitizer_common.h"
  17 #include "sanitizer_common/sanitizer_libc.h"
  18 #include "sanitizer_common/sanitizer_procmaps.h"
  19 #include "tsan_platform.h"
  20 #include "tsan_rtl.h"
  21
  22 namespace __tsan {
  23
  24 #ifndef SANITIZER_GO
  25 void InitializeShadowMemory() {
  26   // Map memory shadow.
  27   uptr shadow =
  28       (uptr)MmapFixedNoReserve(kShadowBeg, kShadowEnd - kShadowBeg, "shadow");
  29   if (shadow != kShadowBeg) {
  30     Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n");
  31     Printf("FATAL: Make sure to compile with -fPIE and "
  32                "to link with -pie (%p, %p).\n", shadow, kShadowBeg);
  33     Die();
  34   }
  35   // This memory range is used for thread stacks and large user mmaps.
  36   // Frequently a thread uses only a small part of stack and similarly
  37   // a program uses a small part of large mmap. On some programs
  38   // we see 20% memory usage reduction without huge pages for this range.
  39   // FIXME: don't use constants here.
  40 #if defined(__x86_64__)
  41   const uptr kMadviseRangeBeg  = 0x7f0000000000ull;
  42   const uptr kMadviseRangeSize = 0x010000000000ull;
  43 #elif defined(__mips64)
  44   const uptr kMadviseRangeBeg  = 0xff00000000ull;
  45   const uptr kMadviseRangeSize = 0x0100000000ull;
  46 #elif defined(__aarch64__)
  47   const uptr kMadviseRangeBeg  = 0x7e00000000ull;
  48   const uptr kMadviseRangeSize = 0x0100000000ull;
  49 #endif
  50   NoHugePagesInRegion(MemToShadow(kMadviseRangeBeg),
  51                       kMadviseRangeSize * kShadowMultiplier);
  52   // Meta shadow is compressing and we don't flush it,
  53   // so it makes sense to mark it as NOHUGEPAGE to not over-allocate memory.
  54   // On one program it reduces memory consumption from 5GB to 2.5GB.
  55   NoHugePagesInRegion(kMetaShadowBeg, kMetaShadowEnd - kMetaShadowBeg);
  56   if (common_flags()->use_madv_dontdump)
  57     DontDumpShadowMemory(kShadowBeg, kShadowEnd - kShadowBeg);
  58   DPrintf("memory shadow: %zx-%zx (%zuGB)\n",
  59       kShadowBeg, kShadowEnd,
  60       (kShadowEnd - kShadowBeg) >> 30);
  61
  62   // Map meta shadow.
  63   uptr meta_size = kMetaShadowEnd - kMetaShadowBeg;
  64   uptr meta =
  65       (uptr)MmapFixedNoReserve(kMetaShadowBeg, meta_size, "meta shadow");
  66   if (meta != kMetaShadowBeg) {
  67     Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n");
  68     Printf("FATAL: Make sure to compile with -fPIE and "
  69                "to link with -pie (%p, %p).\n", meta, kMetaShadowBeg);
  70     Die();
  71   }
  72   if (common_flags()->use_madv_dontdump)
  73     DontDumpShadowMemory(meta, meta_size);
  74   DPrintf("meta shadow: %zx-%zx (%zuGB)\n",
  75       meta, meta + meta_size, meta_size >> 30);
  76
  77   InitializeShadowMemoryPlatform();
  78 }
  79
  80 static void ProtectRange(uptr beg, uptr end) {
  81   CHECK_LE(beg, end);
  82   if (beg == end)
  83     return;
  84   if (beg != (uptr)MmapNoAccess(beg, end - beg)) {
  85     Printf("FATAL: ThreadSanitizer can not protect [%zx,%zx]\n", beg, end);
  86     Printf("FATAL: Make sure you are not using unlimited stack\n");
  87     Die();
  88   }
  89 }
  90
  91 void CheckAndProtect() {
  92   // Ensure that the binary is indeed compiled with -pie.
  93   MemoryMappingLayout proc_maps(true);
  94   uptr p, end, prot;
  95   while (proc_maps.Next(&p, &end, 0, 0, 0, &prot)) {
  96     if (IsAppMem(p))
  97       continue;
  98     if (p >= kHeapMemEnd &&
  99         p < HeapEnd())
 100       continue;
 101     if (prot == 0)  // Zero page or mprotected.
 102       continue;
 103     if (p >= kVdsoBeg)  // vdso
 104       break;
 105     Printf("FATAL: ThreadSanitizer: unexpected memory mapping %p-%p\n", p, end);
 106     Die();
 107   }
 108
 109   ProtectRange(kLoAppMemEnd, kShadowBeg);
 110   ProtectRange(kShadowEnd, kMetaShadowBeg);
 111   ProtectRange(kMetaShadowEnd, kTraceMemBeg);
 112   // Memory for traces is mapped lazily in MapThreadTrace.
 113   // Protect the whole range for now, so that user does not map something here.
 114   ProtectRange(kTraceMemBeg, kTraceMemEnd);
 115   ProtectRange(kTraceMemEnd, kHeapMemBeg);
 116   ProtectRange(HeapEnd(), kHiAppMemBeg);
 117 }
 118 #endif
 119
 120 }  // namespace __tsan
 121
 122 #endif  // SANITIZER_POSIX