Revert r304285, r304297.

r304285 - [sanitizer] Avoid possible deadlock in child process after fork
r304297 - [sanitizer] Trying to fix MAC buildbots after r304285

These changes create deadlock when Tcl calls pthread_create from a
pthread_atfork child handler. More info in the original review at
https://reviews.llvm.org/D33325

llvm-svn: 304735

compiler-rt/lib/asan/asan_allocator.cc

@@ -47,6 +47,8 @@ static u32 RZSize2Log(u32 rz_size) {
   return res;
 }
 
+static AsanAllocator &get_allocator();
+
 // The memory chunk allocated from the underlying allocator looks like this:
 // L L L L L L H H U U U U U U R R
 //   L -- left redzone words (0 or more bytes)
@@ -717,7 +719,7 @@ struct Allocator {
 
 static Allocator instance(LINKER_INITIALIZED);
 
-AsanAllocator &get_allocator() {
+static AsanAllocator &get_allocator() {
   return instance.allocator;
 }
 

compiler-rt/lib/asan/asan_allocator.h

@@ -213,7 +213,5 @@ void asan_mz_force_unlock();
 void PrintInternalAllocatorStats();
 void AsanSoftRssLimitExceededCallback(bool exceeded);
 
-AsanAllocator &get_allocator();
-
 }  // namespace __asan
 #endif  // ASAN_ALLOCATOR_H

compiler-rt/lib/asan/asan_interceptors.cc

@@ -22,7 +22,6 @@
 #include "asan_stats.h"
 #include "asan_suppressions.h"
 #include "lsan/lsan_common.h"
-#include "sanitizer_common/sanitizer_stackdepot.h"
 #include "sanitizer_common/sanitizer_libc.h"
 
 #if SANITIZER_POSIX
@@ -705,25 +704,9 @@ INTERCEPTOR(int, __cxa_atexit, void (*func)(void *), void *arg,
 #endif  // ASAN_INTERCEPT___CXA_ATEXIT
 
 #if ASAN_INTERCEPT_FORK
-static void BeforeFork() {
-  if (SANITIZER_LINUX) {
-    get_allocator().ForceLock();
-    StackDepotLockAll();
-  }
-}
-
-static void AfterFork() {
-  if (SANITIZER_LINUX) {
-    StackDepotUnlockAll();
-    get_allocator().ForceUnlock();
-  }
-}
-
 INTERCEPTOR(int, fork, void) {
   ENSURE_ASAN_INITED();
-  BeforeFork();
   int pid = REAL(fork)();
-  AfterFork();
   return pid;
 }
 #endif  // ASAN_INTERCEPT_FORK

compiler-rt/lib/lsan/lsan_interceptors.cc

@@ -22,7 +22,6 @@
 #include "sanitizer_common/sanitizer_platform_interceptors.h"
 #include "sanitizer_common/sanitizer_platform_limits_posix.h"
 #include "sanitizer_common/sanitizer_posix.h"
-#include "sanitizer_common/sanitizer_stackdepot.h"
 #include "sanitizer_common/sanitizer_tls_get_addr.h"
 #include "lsan.h"
 #include "lsan_allocator.h"
@@ -98,28 +97,6 @@ INTERCEPTOR(void*, valloc, uptr size) {
 }
 #endif
 
-static void BeforeFork() {
-  if (SANITIZER_LINUX) {
-    LockAllocator();
-    StackDepotLockAll();
-  }
-}
-
-static void AfterFork() {
-  if (SANITIZER_LINUX) {
-    StackDepotUnlockAll();
-    UnlockAllocator();
-  }
-}
-
-INTERCEPTOR(int, fork, void) {
-  ENSURE_LSAN_INITED;
-  BeforeFork();
-  int pid = REAL(fork)();
-  AfterFork();
-  return pid;
-}
-
 #if SANITIZER_INTERCEPT_MEMALIGN
 INTERCEPTOR(void*, memalign, uptr alignment, uptr size) {
   ENSURE_LSAN_INITED;
@@ -359,7 +336,6 @@ void InitializeInterceptors() {
   LSAN_MAYBE_INTERCEPT_MALLOPT;
   INTERCEPT_FUNCTION(pthread_create);
   INTERCEPT_FUNCTION(pthread_join);
-  INTERCEPT_FUNCTION(fork);
 
   if (pthread_key_create(&g_thread_finalize_key, &thread_finalize)) {
     Report("LeakSanitizer: failed to create thread key.\n");

compiler-rt/lib/msan/msan_allocator.cc

@@ -12,6 +12,8 @@
 // MemorySanitizer allocator.
 //===----------------------------------------------------------------------===//
 
+#include "sanitizer_common/sanitizer_allocator.h"
+#include "sanitizer_common/sanitizer_allocator_interface.h"
 #include "msan.h"
 #include "msan_allocator.h"
 #include "msan_origin.h"
@@ -20,12 +22,102 @@
 
 namespace __msan {
 
+struct Metadata {
+  uptr requested_size;
+};
+
+struct MsanMapUnmapCallback {
+  void OnMap(uptr p, uptr size) const {}
+  void OnUnmap(uptr p, uptr size) const {
+    __msan_unpoison((void *)p, size);
+
+    // We are about to unmap a chunk of user memory.
+    // Mark the corresponding shadow memory as not needed.
+    uptr shadow_p = MEM_TO_SHADOW(p);
+    ReleaseMemoryPagesToOS(shadow_p, shadow_p + size);
+    if (__msan_get_track_origins()) {
+      uptr origin_p = MEM_TO_ORIGIN(p);
+      ReleaseMemoryPagesToOS(origin_p, origin_p + size);
+    }
+  }
+};
+
+#if defined(__mips64)
+  static const uptr kMaxAllowedMallocSize = 2UL << 30;
+  static const uptr kRegionSizeLog = 20;
+  static const uptr kNumRegions = SANITIZER_MMAP_RANGE_SIZE >> kRegionSizeLog;
+  typedef TwoLevelByteMap<(kNumRegions >> 12), 1 << 12> ByteMap;
+
+  struct AP32 {
+    static const uptr kSpaceBeg = 0;
+    static const u64 kSpaceSize = SANITIZER_MMAP_RANGE_SIZE;
+    static const uptr kMetadataSize = sizeof(Metadata);
+    typedef __sanitizer::CompactSizeClassMap SizeClassMap;
+    static const uptr kRegionSizeLog = __msan::kRegionSizeLog;
+    typedef __msan::ByteMap ByteMap;
+    typedef MsanMapUnmapCallback MapUnmapCallback;
+    static const uptr kFlags = 0;
+  };
+  typedef SizeClassAllocator32<AP32> PrimaryAllocator;
+#elif defined(__x86_64__)
+#if SANITIZER_LINUX && !defined(MSAN_LINUX_X86_64_OLD_MAPPING)
+  static const uptr kAllocatorSpace = 0x700000000000ULL;
+#else
+  static const uptr kAllocatorSpace = 0x600000000000ULL;
+#endif
+  static const uptr kMaxAllowedMallocSize = 8UL << 30;
+
+  struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
+    static const uptr kSpaceBeg = kAllocatorSpace;
+    static const uptr kSpaceSize = 0x40000000000; // 4T.
+    static const uptr kMetadataSize = sizeof(Metadata);
+    typedef DefaultSizeClassMap SizeClassMap;
+    typedef MsanMapUnmapCallback MapUnmapCallback;
+    static const uptr kFlags = 0;
+  };
+
+  typedef SizeClassAllocator64<AP64> PrimaryAllocator;
+
+#elif defined(__powerpc64__)
+  static const uptr kMaxAllowedMallocSize = 2UL << 30;  // 2G
+
+  struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
+    static const uptr kSpaceBeg = 0x300000000000;
+    static const uptr kSpaceSize = 0x020000000000; // 2T.
+    static const uptr kMetadataSize = sizeof(Metadata);
+    typedef DefaultSizeClassMap SizeClassMap;
+    typedef MsanMapUnmapCallback MapUnmapCallback;
+    static const uptr kFlags = 0;
+  };
+
+  typedef SizeClassAllocator64<AP64> PrimaryAllocator;
+#elif defined(__aarch64__)
+  static const uptr kMaxAllowedMallocSize = 2UL << 30;  // 2G
+  static const uptr kRegionSizeLog = 20;
+  static const uptr kNumRegions = SANITIZER_MMAP_RANGE_SIZE >> kRegionSizeLog;
+  typedef TwoLevelByteMap<(kNumRegions >> 12), 1 << 12> ByteMap;
+
+  struct AP32 {
+    static const uptr kSpaceBeg = 0;
+    static const u64 kSpaceSize = SANITIZER_MMAP_RANGE_SIZE;
+    static const uptr kMetadataSize = sizeof(Metadata);
+    typedef __sanitizer::CompactSizeClassMap SizeClassMap;
+    static const uptr kRegionSizeLog = __msan::kRegionSizeLog;
+    typedef __msan::ByteMap ByteMap;
+    typedef MsanMapUnmapCallback MapUnmapCallback;
+    static const uptr kFlags = 0;
+  };
+  typedef SizeClassAllocator32<AP32> PrimaryAllocator;
+#endif
+typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache;
+typedef LargeMmapAllocator<MsanMapUnmapCallback> SecondaryAllocator;
+typedef CombinedAllocator<PrimaryAllocator, AllocatorCache,
+                          SecondaryAllocator> Allocator;
+
 static Allocator allocator;
 static AllocatorCache fallback_allocator_cache;
 static SpinMutex fallback_mutex;
 
-Allocator &get_allocator() { return allocator; }
-
 void MsanAllocatorInit() {
   allocator.Init(
       common_flags()->allocator_may_return_null,

compiler-rt/lib/msan/msan_allocator.h

@@ -15,106 +15,9 @@
 #define MSAN_ALLOCATOR_H
 
 #include "sanitizer_common/sanitizer_common.h"
-#include "sanitizer_common/sanitizer_allocator.h"
-#include "sanitizer_common/sanitizer_allocator_interface.h"
 
 namespace __msan {
 
-struct Metadata {
-  uptr requested_size;
-};
-
-struct MsanMapUnmapCallback {
-  void OnMap(uptr p, uptr size) const {}
-  void OnUnmap(uptr p, uptr size) const {
-    __msan_unpoison((void *)p, size);
-
-    // We are about to unmap a chunk of user memory.
-    // Mark the corresponding shadow memory as not needed.
-    uptr shadow_p = MEM_TO_SHADOW(p);
-    ReleaseMemoryPagesToOS(shadow_p, shadow_p + size);
-    if (__msan_get_track_origins()) {
-      uptr origin_p = MEM_TO_ORIGIN(p);
-      ReleaseMemoryPagesToOS(origin_p, origin_p + size);
-    }
-  }
-};
-
-#if defined(__mips64)
-  static const uptr kMaxAllowedMallocSize = 2UL << 30;
-  static const uptr kRegionSizeLog = 20;
-  static const uptr kNumRegions = SANITIZER_MMAP_RANGE_SIZE >> kRegionSizeLog;
-  typedef TwoLevelByteMap<(kNumRegions >> 12), 1 << 12> ByteMap;
-
-  struct AP32 {
-    static const uptr kSpaceBeg = 0;
-    static const u64 kSpaceSize = SANITIZER_MMAP_RANGE_SIZE;
-    static const uptr kMetadataSize = sizeof(Metadata);
-    typedef __sanitizer::CompactSizeClassMap SizeClassMap;
-    static const uptr kRegionSizeLog = __msan::kRegionSizeLog;
-    typedef __msan::ByteMap ByteMap;
-    typedef MsanMapUnmapCallback MapUnmapCallback;
-    static const uptr kFlags = 0;
-  };
-  typedef SizeClassAllocator32<AP32> PrimaryAllocator;
-#elif defined(__x86_64__)
-#if SANITIZER_LINUX && !defined(MSAN_LINUX_X86_64_OLD_MAPPING)
-  static const uptr kAllocatorSpace = 0x700000000000ULL;
-#else
-  static const uptr kAllocatorSpace = 0x600000000000ULL;
-#endif
-  static const uptr kMaxAllowedMallocSize = 8UL << 30;
-
-  struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
-    static const uptr kSpaceBeg = kAllocatorSpace;
-    static const uptr kSpaceSize = 0x40000000000; // 4T.
-    static const uptr kMetadataSize = sizeof(Metadata);
-    typedef DefaultSizeClassMap SizeClassMap;
-    typedef MsanMapUnmapCallback MapUnmapCallback;
-    static const uptr kFlags = 0;
-  };
-
-  typedef SizeClassAllocator64<AP64> PrimaryAllocator;
-
-#elif defined(__powerpc64__)
-  static const uptr kMaxAllowedMallocSize = 2UL << 30;  // 2G
-
-  struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
-    static const uptr kSpaceBeg = 0x300000000000;
-    static const uptr kSpaceSize = 0x020000000000; // 2T.
-    static const uptr kMetadataSize = sizeof(Metadata);
-    typedef DefaultSizeClassMap SizeClassMap;
-    typedef MsanMapUnmapCallback MapUnmapCallback;
-    static const uptr kFlags = 0;
-  };
-
-  typedef SizeClassAllocator64<AP64> PrimaryAllocator;
-#elif defined(__aarch64__)
-  static const uptr kMaxAllowedMallocSize = 2UL << 30;  // 2G
-  static const uptr kRegionSizeLog = 20;
-  static const uptr kNumRegions = SANITIZER_MMAP_RANGE_SIZE >> kRegionSizeLog;
-  typedef TwoLevelByteMap<(kNumRegions >> 12), 1 << 12> ByteMap;
-
-  struct AP32 {
-    static const uptr kSpaceBeg = 0;
-    static const u64 kSpaceSize = SANITIZER_MMAP_RANGE_SIZE;
-    static const uptr kMetadataSize = sizeof(Metadata);
-    typedef __sanitizer::CompactSizeClassMap SizeClassMap;
-    static const uptr kRegionSizeLog = __msan::kRegionSizeLog;
-    typedef __msan::ByteMap ByteMap;
-    typedef MsanMapUnmapCallback MapUnmapCallback;
-    static const uptr kFlags = 0;
-  };
-  typedef SizeClassAllocator32<AP32> PrimaryAllocator;
-#endif
-typedef SizeClassAllocatorLocalCache<PrimaryAllocator> AllocatorCache;
-typedef LargeMmapAllocator<MsanMapUnmapCallback> SecondaryAllocator;
-typedef CombinedAllocator<PrimaryAllocator, AllocatorCache,
-                          SecondaryAllocator> Allocator;
-
-
-Allocator &get_allocator();
-
 struct MsanThreadLocalMallocStorage {
   uptr quarantine_cache[16];
   // Allocator cache contains atomic_uint64_t which must be 8-byte aligned.

compiler-rt/lib/msan/msan_interceptors.cc

@@ -1201,7 +1201,6 @@ INTERCEPTOR(void *, shmat, int shmid, const void *shmaddr, int shmflg) {
 }
 
 static void BeforeFork() {
-  get_allocator().ForceLock();
   StackDepotLockAll();
   ChainedOriginDepotLockAll();
 }
@@ -1209,7 +1208,6 @@ static void BeforeFork() {
 static void AfterFork() {
   ChainedOriginDepotUnlockAll();
   StackDepotUnlockAll();
-  get_allocator().ForceUnlock();
 }
 
 INTERCEPTOR(int, fork, void) {

compiler-rt/test/sanitizer_common/TestCases/Linux/allocator_fork_no_hang.cc

@@ -1,118 +0,0 @@
-// https://github.com/google/sanitizers/issues/774
-// Test that sanitizer allocator is fork-safe.
-// Run a number of threads that perform memory allocation/deallocation, then fork
-// and verify that malloc/free do not deadlock in the child process.
-
-// RUN: %clangxx -std=c++11 -O0 %s -o %t
-// RUN: ASAN_OPTIONS=detect_leaks=0 %run %t 2>&1 | FileCheck %s
-
-// Fun fact: if test output is redirected to a file (as opposed to
-// being piped directly to FileCheck), we may lose some "done"s due to
-// a kernel bug:
-// https://lkml.org/lkml/2014/2/17/324
-
-// UNSUPPORTED: tsan
-
-// Flaky on PPC64.
-// UNSUPPORTED: powerpc64-target-arch
-// UNSUPPORTED: powerpc64le-target-arch
-
-#include <pthread.h>
-#include <unistd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <sys/time.h>
-#include <signal.h>
-#include <errno.h>
-
-int done;
-
-void *worker(void *arg) {
-  while (true) {
-    void *p = malloc(4);
-    if (__atomic_load_n(&done, __ATOMIC_RELAXED))
-      return 0;
-  }
-  return 0;
-}
-
-// Run through malloc/free in the child process.
-// This can deadlock on allocator cache refilling.
-void child() {
-  for (int i = 0; i < 10000; ++i) {
-    void *p = malloc(4);
-  }
-  write(2, "done\n", 5);
-}
-
-void test() {
-  const int kThreads = 10;
-  pthread_t t[kThreads];
-  for (int i = 0; i < kThreads; ++i)
-    pthread_create(&t[i], NULL, worker, (void*)(long)i);
-  usleep(100000);
-  pid_t pid = fork();
-  if (pid) {
-    // parent
-    __atomic_store_n(&done, 1, __ATOMIC_RELAXED);
-    pid_t p;
-    while ((p = wait(NULL)) == -1) {  }
-  } else {
-    // child
-    child();
-  }
-}
-
-int main() {
-  const int kChildren = 30;
-  for (int i = 0; i < kChildren; ++i) {
-    pid_t pid = fork();
-    if (pid) {
-      // parent
-    } else {
-      test();
-      exit(0);
-    }
-  }
-
-  for (int i = 0; i < kChildren; ++i) {
-    pid_t p;
-    while ((p = wait(NULL)) == -1) {  }
-  }
-
-  return 0;
-}
-
-// Expect 30 (== kChildren) "done" messages.
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done
-// CHECK: done