1 files changed, 58 insertions, 22 deletions

diff --git a/ipc/chromium/src/base/lock_impl_posix.cc b/ipc/chromium/src/base/lock_impl_posix.cc
index 0513cf0e65..b0fbfe5f04 100644
--- a/ipc/chromium/src/base/lock_impl_posix.cc
+++ b/ipc/chromium/src/base/lock_impl_posix.cc
@@ -1,49 +1,85 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/lock_impl.h"
 
 #include <errno.h>
+#include <string.h>
 
 #include "base/logging.h"
+#include "base/lock.h"
+
+namespace base {
+namespace internal {
+
+#define PRIORITY_INHERITANCE_LOCKS_POSSIBLE() 1
 
 LockImpl::LockImpl() {
-#ifndef NDEBUG
-  // In debug, setup attributes for lock error checking.
   pthread_mutexattr_t mta;
   int rv = pthread_mutexattr_init(&mta);
-  DCHECK_EQ(rv, 0);
+
+  DCHECK_EQ(rv, 0) << ". " << strerror(rv);
+#if PRIORITY_INHERITANCE_LOCKS_POSSIBLE()
+  if (PriorityInheritanceAvailable()) {
+    rv = pthread_mutexattr_setprotocol(&mta, PTHREAD_PRIO_INHERIT);
+    DCHECK_EQ(rv, 0) << ". " << strerror(rv);
+  }
+#endif
+#ifndef NDEBUG
+  // In debug, setup attributes for lock error checking.
   rv = pthread_mutexattr_settype(&mta, PTHREAD_MUTEX_ERRORCHECK);
-  DCHECK_EQ(rv, 0);
-  rv = pthread_mutex_init(&os_lock_, &mta);
-  DCHECK_EQ(rv, 0);
-  rv = pthread_mutexattr_destroy(&mta);
-  DCHECK_EQ(rv, 0);
-#else
-  // In release, go with the default lock attributes.
-  pthread_mutex_init(&os_lock_, NULL);
+  DCHECK_EQ(rv, 0) << ". " << strerror(rv);
 #endif
+  rv = pthread_mutex_init(&native_handle_, &mta);
+  DCHECK_EQ(rv, 0) << ". " << strerror(rv);
+  rv = pthread_mutexattr_destroy(&mta);
+  DCHECK_EQ(rv, 0) << ". " << strerror(rv);
 }
 
 LockImpl::~LockImpl() {
-  int rv = pthread_mutex_destroy(&os_lock_);
-  DCHECK_EQ(rv, 0);
+  int rv = pthread_mutex_destroy(&native_handle_);
+  DCHECK_EQ(rv, 0) << ". " << strerror(rv);
 }
 
 bool LockImpl::Try() {
-  int rv = pthread_mutex_trylock(&os_lock_);
-  DCHECK(rv == 0 || rv == EBUSY);
-  return rv == 0;
+  int rv = pthread_mutex_trylock(&native_handle_);
+  DCHECK(rv == 0 || rv == EBUSY) << ". " << strerror(rv);
 }
 
 void LockImpl::Lock() {
-  int rv = pthread_mutex_lock(&os_lock_);
-  DCHECK_EQ(rv, 0);
+  int rv = pthread_mutex_lock(&native_handle_);
+  DCHECK_EQ(rv, 0) << ". " << strerror(rv);
 }
 
 void LockImpl::Unlock() {
-  int rv = pthread_mutex_unlock(&os_lock_);
-  DCHECK_EQ(rv, 0);
+  int rv = pthread_mutex_unlock(&native_handle_);
+  DCHECK_EQ(rv, 0) << ". " << strerror(rv);
+}
+
+// static
+bool LockImpl::PriorityInheritanceAvailable() {
+#if PRIORITY_INHERITANCE_LOCKS_POSSIBLE() && defined(OS_MACOSX)
+  return true;
+#else
+  // Security concerns prevent the use of priority inheritance mutexes on Linux.
+  //   * CVE-2010-0622 - wake_futex_pi unlocks incorrect, possible DoS.
+  //     https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-0622
+  //   * CVE-2012-6647 - Linux < 3.5.1, futex_wait_requeue_pi possible DoS.
+  //     https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2012-6647
+  //   * CVE-2014-3153 - Linux <= 3.14.5, futex_requeue, privilege escalation.
+  //     https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-3153
+  //
+  // If the above were all addressed, we still need a runtime check to deal with
+  // the bug below.
+  //   * glibc Bug 14652: https://sourceware.org/bugzilla/show_bug.cgi?id=14652
+  //     Fixed in glibc 2.17.
+  //     Priority inheritance mutexes may deadlock with condition variables
+  //     during recacquisition of the mutex after the condition variable is
+  //     signalled.
+  return false;
+#endif
 }
+
+}  // namespace internal
+}  // namespace base