Parse shmmax as a uint64

base/sys_info_linux.cc

 // 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/sys_info.h"
 
 #include <limits>
 
 #include "base/files/file_util.h"
 #include "base/lazy_instance.h"
@@ skipping 18 matching lines @@
 }
 
 size_t MaxSharedMemorySize() {
   std::string contents;
   base::ReadFileToString(base::FilePath("/proc/sys/kernel/shmmax"), &contents);
   DCHECK(!contents.empty());
   if (!contents.empty() && contents[contents.length() - 1] == '\n') {
     contents.erase(contents.length() - 1);
   }
 
-  int64 limit;
-  if (!base::StringToInt64(contents, &limit)) {
+  uint64 limit;
+  if (!base::StringToUint64(contents, &limit)) {
     limit = 0;
   }
-  if (limit < 0 ||
-      static_cast<uint64>(limit) > std::numeric_limits<size_t>::max()) {
+  if (limit > std::numeric_limits<size_t>::max()) {
     limit = 0;
   }
   DCHECK(limit > 0);
   return static_cast<size_t>(limit);
 }
 
 base::LazyInstance<
     base::internal::LazySysInfoValue<int64, AmountOfPhysicalMemory> >::Leaky
     g_lazy_physical_memory = LAZY_INSTANCE_INITIALIZER;
 base::LazyInstance<
@@ skipping 36 matching lines @@
       if (line.compare(0, strlen(kCpuModelPrefix), kCpuModelPrefix) == 0) {
         size_t pos = line.find(": ");
         return line.substr(pos + 2);
       }
     }
   }
   return std::string();
 }
 
 }  // namespace base