Use O_CLOEXEC when calling open() in rand_util_posix

base/rand_util_posix.cc

 // Copyright (c) 2012 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/rand_util.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <unistd.h>
 
 #include "base/files/file_util.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
+#include "base/posix/eintr_wrapper.h"
 
 namespace {
 
 // We keep the file descriptor for /dev/urandom around so we don't need to
 // reopen it (which is expensive), and since we may not even be able to reopen
 // it if we are later put in a sandbox. This class wraps the file descriptor so
 // we can use LazyInstance to handle opening it on the first access.
 class URandomFd {
  public:
-  URandomFd() : fd_(open("/dev/urandom", O_RDONLY)) {
+  URandomFd() : fd_(HANDLE_EINTR(open("/dev/urandom", O_RDONLY | O_CLOEXEC))) {
     DCHECK_GE(fd_, 0) << "Cannot open /dev/urandom: " << errno;
   }
 
   ~URandomFd() { close(fd_); }
 
   int fd() const { return fd_; }
 
  private:
   const int fd_;
 };
@@ skipping 16 matching lines @@
   const bool success =
       ReadFromFD(urandom_fd, static_cast<char*>(output), output_length);
   CHECK(success);
 }
 
 int GetUrandomFD(void) {
   return g_urandom_fd.Pointer()->fd();
 }
 
 }  // namespace base