Linux: don't try and read shmmax in the sandbox.

chrome/browser/zygote_main_linux.cc

 // Copyright (c) 2009 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 <unistd.h>
 #include <sys/epoll.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/signal.h>
 #include <sys/prctl.h>
 #include <sys/wait.h>
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/eintr_wrapper.h"
 #include "base/global_descriptors_posix.h"
 #include "base/pickle.h"
 #include "base/rand_util.h"
+#include "base/sys_info.h"
 #include "base/unix_domain_socket_posix.h"
 
 #include "chrome/browser/zygote_host_linux.h"
 #include "chrome/common/chrome_descriptors.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/main_function_params.h"
 #include "chrome/common/process_watcher.h"
 #include "chrome/common/sandbox_methods_linux.h"
 
 #include "skia/ext/SkFontHost_fontconfig_control.h"
@@ skipping 274 matching lines @@
     char* endptr;
     const long fd_long = strtol(sandbox_fd_string, &endptr, 10);
     if (!*sandbox_fd_string || *endptr || fd_long < 0 || fd_long > INT_MAX)
       return false;
     const int fd = fd_long;
 
     // Before entering the sandbox, "prime" any systems that need to open
     // files and cache the results or the descriptors.
     base::RandUint64();
 
+    base::SysInfo::MaxSharedMemorySize();
+
     // To make wcstombs/mbstowcs work in a renderer, setlocale() has to be
     // called before the sandbox is triggered. It's possible to avoid calling
     // setlocale() by pulling out the conversion between FilePath and
     // WebCore String out of the renderer and using string16 in place of
     // FilePath for IPC.
     const char* locale = setlocale(LC_ALL, "");
     LOG_IF(WARNING, locale == NULL) << "setlocale failed.";
 
 #if defined(ARCH_CPU_X86)
     PATCH_GLOBAL_OFFSET_TABLE(localtime, sandbox_wrapper::localtime);
@@ skipping 59 matching lines @@
 bool ZygoteMain(const MainFunctionParams& params) {
   if (!MaybeEnterChroot()) {
     LOG(FATAL) << "Failed to enter sandbox. Fail safe abort. (errno: "
                << errno << ")";
     return false;
   }
 
   Zygote zygote;
   return zygote.ProcessRequests();
 }