Make the seccomp sandbox compatible with tcmalloc:...

sandbox/linux/seccomp/library.h

 // Copyright (c) 2010 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.
 
 #ifndef LIBRARY_H__
 #define LIBRARY_H__
 
 #include <elf.h>
+#include <functional>
 #include <map>
 #include <set>
 #include <string>
 #include <string.h>
 #include <sys/mman.h>
 
 #include "maps.h"
 
 #if defined(__x86_64__)
 typedef Elf64_Ehdr Elf_Ehdr;
@@ skipping 109 matching lines @@
   const int getSectionIndex(const string& section);
   void makeWritable(bool state) const;
   void patchSystemCalls();
   bool isVDSO() const { return isVDSO_; }
 
  protected:
   bool parseSymbols();
 
  private:
   class GreaterThan : public std::binary_function<Elf_Addr, Elf_Addr, bool> {
+    // We create the RangeMap with a GreaterThan rather than the default
+    // comparator, as that allows us to use lower_bound() to find memory
+    // mappings.
    public:
     bool operator() (Elf_Addr s1, Elf_Addr s2) const {
       return s1 > s2;
     }
   };
 
   struct Range {
     Range(void* start, void* stop, int prot) :
         start(start), stop(stop), prot(prot) { }
     void* start;
     void* stop;
     int   prot;
   };
 
-  typedef std::map<Elf_Addr, Range, GreaterThan> RangeMap;
-  typedef std::map<string, std::pair<int, Elf_Shdr> > SectionTable;
-  typedef std::map<string, Elf_Sym> SymbolTable;
-  typedef std::map<string, Elf_Addr> PltTable;
+  typedef std::map<Elf_Addr, Range, GreaterThan,
+                   SystemAllocator<std::pair<const Elf_Addr,
+                                             Range> > > RangeMap;
+  typedef std::map<string, std::pair<int, Elf_Shdr>, std::less<string>,
+                   SystemAllocator<std::pair<const string,
+                                             std::pair<int, Elf_Shdr> > > >
+                   SectionTable;
+  typedef std::map<string, Elf_Sym, std::less<string>,
+                   SystemAllocator<std::pair<const string,
+                                             Elf_Sym> > > SymbolTable;
+  typedef std::map<string, Elf_Addr, std::less<string>,
+                   SystemAllocator<std::pair<const string,
+                                             Elf_Addr> > > PltTable;
 
   char* getBytes(char* dst, const char* src, ssize_t len);
   static bool isSafeInsn(unsigned short insn);
   static int isSimpleSystemCall(char *start, char *end);
   static char* getScratchSpace(const Maps* maps, char* near, int needed,
                                char** extraSpace, int* extraLength);
   void patchSystemCallsInFunction(const Maps* maps, char *start, char *end,
                                   char** extraSpace, int* extraLength);
   int  patchVSystemCalls();
   void patchVDSO(char** extraSpace, int* extraLength);
@@ skipping 11 matching lines @@
   char*           image_;
   size_t          image_size_;
   static char*    __kernel_vsyscall;
   static char*    __kernel_sigreturn;
   static char*    __kernel_rt_sigreturn;
 };
 
 } // namespace
 
 #endif // LIBRARY_H__