contrib/compiler-rt/lib/scudo/scudo_tls_linux.cpp

   1 //===-- scudo_tls_linux.cpp -------------------------------------*- C++ -*-===//
   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 /// Scudo thread local structure implementation for platforms supporting
  11 /// thread_local.
  12 ///
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "sanitizer_common/sanitizer_platform.h"
  16
  17 #if SANITIZER_LINUX && !SANITIZER_ANDROID
  18
  19 #include "scudo_tls.h"
  20
  21 #include <pthread.h>
  22
  23 namespace __scudo {
  24
  25 static pthread_once_t GlobalInitialized = PTHREAD_ONCE_INIT;
  26 static pthread_key_t PThreadKey;
  27
  28 __attribute__((tls_model("initial-exec")))
  29 THREADLOCAL ThreadState ScudoThreadState = ThreadNotInitialized;
  30 __attribute__((tls_model("initial-exec")))
  31 THREADLOCAL ScudoThreadContext ThreadLocalContext;
  32
  33 static void teardownThread(void *Ptr) {
  34   uptr I = reinterpret_cast<uptr>(Ptr);
  35   // The glibc POSIX thread-local-storage deallocation routine calls user
  36   // provided destructors in a loop of PTHREAD_DESTRUCTOR_ITERATIONS.
  37   // We want to be called last since other destructors might call free and the
  38   // like, so we wait until PTHREAD_DESTRUCTOR_ITERATIONS before draining the
  39   // quarantine and swallowing the cache.
  40   if (I > 1) {
  41     // If pthread_setspecific fails, we will go ahead with the teardown.
  42     if (LIKELY(pthread_setspecific(PThreadKey,
  43                                    reinterpret_cast<void *>(I - 1)) == 0))
  44       return;
  45   }
  46   ThreadLocalContext.commitBack();
  47   ScudoThreadState = ThreadTornDown;
  48 }
  49
  50
  51 static void initOnce() {
  52   CHECK_EQ(pthread_key_create(&PThreadKey, teardownThread), 0);
  53   initScudo();
  54 }
  55
  56 void initThread() {
  57   CHECK_EQ(pthread_once(&GlobalInitialized, initOnce), 0);
  58   CHECK_EQ(pthread_setspecific(PThreadKey, reinterpret_cast<void *>(
  59       GetPthreadDestructorIterations())), 0);
  60   ThreadLocalContext.init();
  61   ScudoThreadState = ThreadInitialized;
  62 }
  63
  64 }  // namespace __scudo
  65
  66 #endif  // SANITIZER_LINUX && !SANITIZER_ANDROID