[tsan] Shadow memory setup for OS X

[kubamracek]

Summary

The shadow memory initialization in tsan_platform_mac.cc needs to be updated to also initialize the meta shadow and to mprotect the memory ranges that need to be avoided. This patch moves most of the Linux implementation of InitializeShadowMemory, ProtectRange and CheckAndProtect into tsan_rt.cc so it can be reused on OS X as well.

[dvyukov]

Please shuffle code differently.
I have 2 concerns here:

1. tsan_rtl.cc is already a bit of trash can, and I don't want it to continue moving in that direction (initially it was meant for abstract state-machine logic only).
2. The distinction between InitializeShadowMemory and InitializeShadowMemoryPlatform is not clear, e.g. what will you put in what function on windows?

So please put the common functions into a new tsan_platform_posix.cc, put definition of CheckAndProtect into tsan_platform.h, call InitializeShadowMemoryPlatform from within InitializeShadowMemory (so that Initialize only calls InitializeShadowMemory, and then it's platform business what it does there).

[kubamracek]

Updating patch.

[dvyukov]

Thanks!

compiler-rt/trunk/lib/tsan/CMakeLists.txt

set(TSAN_SOURCES
   rtl/tsan_suppressions.cc
   rtl/tsan_symbolize.cc
   rtl/tsan_sync.cc)
 
 set(TSAN_CXX_SOURCES
   rtl/tsan_new_delete.cc)
 
 if(APPLE)
-  list(APPEND TSAN_SOURCES rtl/tsan_platform_mac.cc)
+  list(APPEND TSAN_SOURCES
+    rtl/tsan_platform_mac.cc
+    rtl/tsan_platform_posix.cc)
 elseif(UNIX)
   # Assume Linux
   list(APPEND TSAN_SOURCES
-    rtl/tsan_platform_linux.cc)
+    rtl/tsan_platform_linux.cc
+    rtl/tsan_platform_posix.cc)
 endif()
 
 set(TSAN_HEADERS
   rtl/tsan_clock.h
   rtl/tsan_defs.h
   rtl/tsan_dense_alloc.h
   rtl/tsan_fd.h
   rtl/tsan_flags.h

compiler-rt/trunk/lib/tsan/rtl/tsan_platform.h

 uptr ALWAYS_INLINE GetThreadTraceHeader(int tid) {
   uptr p = kTraceMemBeg + (uptr)tid * kTotalTraceSize
       + kTraceSize * sizeof(Event);
   DCHECK_LT(p, kTraceMemEnd);
   return p;
 }
 
 void InitializePlatform();
+void CheckAndProtect();
+void InitializeShadowMemoryPlatform();
 void FlushShadowMemory();
 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive);
 
 // Says whether the addr relates to a global var.
 // Guesses with high probability, may yield both false positives and negatives.
 bool IsGlobalVar(uptr addr);
 int ExtractResolvFDs(void *state, int *fds, int nfd);
 int ExtractRecvmsgFDs(void *msg, int *fds, int nfd);
 
 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
     void *abstime), void *c, void *m, void *abstime,
     void(*cleanup)(void *arg), void *arg);
 
 }  // namespace __tsan
 
 #endif  // TSAN_PLATFORM_H

compiler-rt/trunk/lib/tsan/rtl/tsan_platform_linux.cc

 
 void FlushShadowMemory() {
 #if SANITIZER_LINUX
   StopTheWorld(FlushShadowMemoryCallback, 0);
 #endif
 }
 
 #ifndef SANITIZER_GO
-static void ProtectRange(uptr beg, uptr end) {
-  CHECK_LE(beg, end);
-  if (beg == end)
-    return;
-  if (beg != (uptr)MmapNoAccess(beg, end - beg)) {
-    Printf("FATAL: ThreadSanitizer can not protect [%zx,%zx]\n", beg, end);
-    Printf("FATAL: Make sure you are not using unlimited stack\n");
-    Die();
-  }
-}
-
 // Mark shadow for .rodata sections with the special kShadowRodata marker.
 // Accesses to .rodata can't race, so this saves time, memory and trace space.
 static void MapRodata() {
   // First create temp file.
   const char *tmpdir = GetEnv("TMPDIR");
   if (tmpdir == 0)
     tmpdir = GetEnv("TEST_TMPDIR");
 #ifdef P_tmpdir
if (name[0] != 0 && name[0] != '['
         internal_mmap(p, Min<uptr>(marker.size(), shadow_end - p),
                       PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0);
       }
     }
   }
   internal_close(fd);
 }
 
-void InitializeShadowMemory() {
-  // Map memory shadow.
-  uptr shadow =
-      (uptr)MmapFixedNoReserve(kShadowBeg, kShadowEnd - kShadowBeg, "shadow");
-  if (shadow != kShadowBeg) {
-    Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n");
-    Printf("FATAL: Make sure to compile with -fPIE and "
-               "to link with -pie (%p, %p).\n", shadow, kShadowBeg);
-    Die();
-  }
-  // This memory range is used for thread stacks and large user mmaps.
-  // Frequently a thread uses only a small part of stack and similarly
-  // a program uses a small part of large mmap. On some programs
-  // we see 20% memory usage reduction without huge pages for this range.
-  // FIXME: don't use constants here.
-#if defined(__x86_64__)
-  const uptr kMadviseRangeBeg  = 0x7f0000000000ull;
-  const uptr kMadviseRangeSize = 0x010000000000ull;
-#elif defined(__mips64)
-  const uptr kMadviseRangeBeg  = 0xff00000000ull;
-  const uptr kMadviseRangeSize = 0x0100000000ull;
-#elif defined(__aarch64__)
-  const uptr kMadviseRangeBeg  = 0x7e00000000ull;
-  const uptr kMadviseRangeSize = 0x0100000000ull;
-#endif
-  NoHugePagesInRegion(MemToShadow(kMadviseRangeBeg),
-                      kMadviseRangeSize * kShadowMultiplier);
-  // Meta shadow is compressing and we don't flush it,
-  // so it makes sense to mark it as NOHUGEPAGE to not over-allocate memory.
-  // On one program it reduces memory consumption from 5GB to 2.5GB.
-  NoHugePagesInRegion(kMetaShadowBeg, kMetaShadowEnd - kMetaShadowBeg);
-  if (common_flags()->use_madv_dontdump)
-    DontDumpShadowMemory(kShadowBeg, kShadowEnd - kShadowBeg);
-  DPrintf("memory shadow: %zx-%zx (%zuGB)\n",
-      kShadowBeg, kShadowEnd,
-      (kShadowEnd - kShadowBeg) >> 30);
-
-  // Map meta shadow.
-  uptr meta_size = kMetaShadowEnd - kMetaShadowBeg;
-  uptr meta =
-      (uptr)MmapFixedNoReserve(kMetaShadowBeg, meta_size, "meta shadow");
-  if (meta != kMetaShadowBeg) {
-    Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n");
-    Printf("FATAL: Make sure to compile with -fPIE and "
-               "to link with -pie (%p, %p).\n", meta, kMetaShadowBeg);
-    Die();
-  }
-  if (common_flags()->use_madv_dontdump)
-    DontDumpShadowMemory(meta, meta_size);
-  DPrintf("meta shadow: %zx-%zx (%zuGB)\n",
-      meta, meta + meta_size, meta_size >> 30);
-
+void InitializeShadowMemoryPlatform() {
   MapRodata();
 }
 
 static void InitDataSeg() {
   MemoryMappingLayout proc_maps(true);
   uptr start, end, offset;
   char name[128];
 #if SANITIZER_FREEBSD
#else
   }
 #endif
   DPrintf("guessed data_start=%p data_end=%p\n",  g_data_start, g_data_end);
   CHECK_LT(g_data_start, g_data_end);
   CHECK_GE((uptr)&g_data_start, g_data_start);
   CHECK_LT((uptr)&g_data_start, g_data_end);
 }
 
-static void CheckAndProtect() {
-  // Ensure that the binary is indeed compiled with -pie.
-  MemoryMappingLayout proc_maps(true);
-  uptr p, end;
-  while (proc_maps.Next(&p, &end, 0, 0, 0, 0)) {
-    if (IsAppMem(p))
-      continue;
-    if (p >= kHeapMemEnd &&
-        p < HeapEnd())
-      continue;
-    if (p >= kVdsoBeg)  // vdso
-      break;
-    Printf("FATAL: ThreadSanitizer: unexpected memory mapping %p-%p\n", p, end);
-    Die();
-  }
-
-  ProtectRange(kLoAppMemEnd, kShadowBeg);
-  ProtectRange(kShadowEnd, kMetaShadowBeg);
-  ProtectRange(kMetaShadowEnd, kTraceMemBeg);
-  // Memory for traces is mapped lazily in MapThreadTrace.
-  // Protect the whole range for now, so that user does not map something here.
-  ProtectRange(kTraceMemBeg, kTraceMemEnd);
-  ProtectRange(kTraceMemEnd, kHeapMemBeg);
-  ProtectRange(HeapEnd(), kHiAppMemBeg);
-}
 #endif  // #ifndef SANITIZER_GO
 
 void InitializePlatform() {
   DisableCoreDumperIfNecessary();
 
   // Go maps shadow memory lazily and works fine with limited address space.
   // Unlimited stack is not a problem as well, because the executable
   // is not compiled with -pie.

compiler-rt/trunk/lib/tsan/rtl/tsan_platform_mac.cc

 
 void FlushShadowMemory() {
 }
 
 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
 }
 
 #ifndef SANITIZER_GO
-void InitializeShadowMemory() {
-  uptr shadow = (uptr)MmapFixedNoReserve(kShadowBeg,
-    kShadowEnd - kShadowBeg);
-  if (shadow != kShadowBeg) {
-    Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n");
-    Printf("FATAL: Make sure to compile with -fPIE and "
-           "to link with -pie.\n");
-    Die();
-  }
-  if (common_flags()->use_madv_dontdump)
-    DontDumpShadowMemory(kShadowBeg, kShadowEnd - kShadowBeg);
-  DPrintf("kShadow %zx-%zx (%zuGB)\n",
-      kShadowBeg, kShadowEnd,
-      (kShadowEnd - kShadowBeg) >> 30);
-  DPrintf("kAppMem %zx-%zx (%zuGB)\n",
-      kAppMemBeg, kAppMemEnd,
-      (kAppMemEnd - kAppMemBeg) >> 30);
-}
+void InitializeShadowMemoryPlatform() { }
 #endif
 
 void InitializePlatform() {
   DisableCoreDumperIfNecessary();
+#ifndef SANITIZER_GO
+  CheckAndProtect();
+#endif
 }
 
 #ifndef SANITIZER_GO
 // Note: this function runs with async signals enabled,
 // so it must not touch any tsan state.
 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
     void *abstime), void *c, void *m, void *abstime,
     void(*cleanup)(void *arg), void *arg) {

compiler-rt/trunk/lib/tsan/rtl/tsan_platform_posix.cc

+//===-- tsan_platform_posix.cc --------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of ThreadSanitizer (TSan), a race detector.
+//
+// POSIX-specific code.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_common/sanitizer_platform.h"
+#if SANITIZER_POSIX
+
+#include "sanitizer_common/sanitizer_common.h"
+#include "sanitizer_common/sanitizer_libc.h"
+#include "sanitizer_common/sanitizer_procmaps.h"
+#include "tsan_platform.h"
+#include "tsan_rtl.h"
+
+namespace __tsan {
+
+#ifndef SANITIZER_GO
+void InitializeShadowMemory() {
+  // Map memory shadow.
+  uptr shadow =
+      (uptr)MmapFixedNoReserve(kShadowBeg, kShadowEnd - kShadowBeg, "shadow");
+  if (shadow != kShadowBeg) {
+    Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n");
+    Printf("FATAL: Make sure to compile with -fPIE and "
+               "to link with -pie (%p, %p).\n", shadow, kShadowBeg);
+    Die();
+  }
+  // This memory range is used for thread stacks and large user mmaps.
+  // Frequently a thread uses only a small part of stack and similarly
+  // a program uses a small part of large mmap. On some programs
+  // we see 20% memory usage reduction without huge pages for this range.
+  // FIXME: don't use constants here.
+#if defined(__x86_64__)
+  const uptr kMadviseRangeBeg  = 0x7f0000000000ull;
+  const uptr kMadviseRangeSize = 0x010000000000ull;
+#elif defined(__mips64)
+  const uptr kMadviseRangeBeg  = 0xff00000000ull;
+  const uptr kMadviseRangeSize = 0x0100000000ull;
+#elif defined(__aarch64__)
+  const uptr kMadviseRangeBeg  = 0x7e00000000ull;
+  const uptr kMadviseRangeSize = 0x0100000000ull;
+#endif
+  NoHugePagesInRegion(MemToShadow(kMadviseRangeBeg),
+                      kMadviseRangeSize * kShadowMultiplier);
+  // Meta shadow is compressing and we don't flush it,
+  // so it makes sense to mark it as NOHUGEPAGE to not over-allocate memory.
+  // On one program it reduces memory consumption from 5GB to 2.5GB.
+  NoHugePagesInRegion(kMetaShadowBeg, kMetaShadowEnd - kMetaShadowBeg);
+  if (common_flags()->use_madv_dontdump)
+    DontDumpShadowMemory(kShadowBeg, kShadowEnd - kShadowBeg);
+  DPrintf("memory shadow: %zx-%zx (%zuGB)\n",
+      kShadowBeg, kShadowEnd,
+      (kShadowEnd - kShadowBeg) >> 30);
+
+  // Map meta shadow.
+  uptr meta_size = kMetaShadowEnd - kMetaShadowBeg;
+  uptr meta =
+      (uptr)MmapFixedNoReserve(kMetaShadowBeg, meta_size, "meta shadow");
+  if (meta != kMetaShadowBeg) {
+    Printf("FATAL: ThreadSanitizer can not mmap the shadow memory\n");
+    Printf("FATAL: Make sure to compile with -fPIE and "
+               "to link with -pie (%p, %p).\n", meta, kMetaShadowBeg);
+    Die();
+  }
+  if (common_flags()->use_madv_dontdump)
+    DontDumpShadowMemory(meta, meta_size);
+  DPrintf("meta shadow: %zx-%zx (%zuGB)\n",
+      meta, meta + meta_size, meta_size >> 30);
+
+  InitializeShadowMemoryPlatform();
+}
+
+static void ProtectRange(uptr beg, uptr end) {
+  CHECK_LE(beg, end);
+  if (beg == end)
+    return;
+  if (beg != (uptr)MmapNoAccess(beg, end - beg)) {
+    Printf("FATAL: ThreadSanitizer can not protect [%zx,%zx]\n", beg, end);
+    Printf("FATAL: Make sure you are not using unlimited stack\n");
+    Die();
+  }
+}
+
+void CheckAndProtect() {
+  // Ensure that the binary is indeed compiled with -pie.
+  MemoryMappingLayout proc_maps(true);
+  uptr p, end, prot;
+  while (proc_maps.Next(&p, &end, 0, 0, 0, &prot)) {
+    if (IsAppMem(p))
+      continue;
+    if (p >= kHeapMemEnd &&
+        p < HeapEnd())
+      continue;
+    if (prot == 0)  // Zero page or mprotected.
+      continue;
+    if (p >= kVdsoBeg)  // vdso
+      break;
+    Printf("FATAL: ThreadSanitizer: unexpected memory mapping %p-%p\n", p, end);
+    Die();
+  }
+
+  ProtectRange(kLoAppMemEnd, kShadowBeg);
+  ProtectRange(kShadowEnd, kMetaShadowBeg);
+  ProtectRange(kMetaShadowEnd, kTraceMemBeg);
+  // Memory for traces is mapped lazily in MapThreadTrace.
+  // Protect the whole range for now, so that user does not map something here.
+  ProtectRange(kTraceMemBeg, kTraceMemEnd);
+  ProtectRange(kTraceMemEnd, kHeapMemBeg);
+  ProtectRange(HeapEnd(), kHiAppMemBeg);
+}
+#endif
+
+}  // namespace __tsan
+
+#endif  // SANITIZER_POSIX