third_party/tcmalloc/vendor/src/libc_override_glibc.h

   1 // Copyright (c) 2011, Google Inc.
   2 // All rights reserved.
   3 //
   4 // Redistribution and use in source and binary forms, with or without
   5 // modification, are permitted provided that the following conditions are
   6 // met:
   7 //
   8 //     * Redistributions of source code must retain the above copyright
   9 // notice, this list of conditions and the following disclaimer.
  10 //     * Redistributions in binary form must reproduce the above
  11 // copyright notice, this list of conditions and the following disclaimer
  12 // in the documentation and/or other materials provided with the
  13 // distribution.
  14 //     * Neither the name of Google Inc. nor the names of its
  15 // contributors may be used to endorse or promote products derived from
  16 // this software without specific prior written permission.
  17 //
  18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29
  30 // ---
  31 // Author: Craig Silverstein <opensource@google.com>
  32 //
  33 // Used to override malloc routines on systems that are using glibc.
  34
  35 #ifndef TCMALLOC_LIBC_OVERRIDE_GLIBC_INL_H_
  36 #define TCMALLOC_LIBC_OVERRIDE_GLIBC_INL_H_
  37
  38 #include <config.h>
  39 #include <features.h>     // for __GLIBC__
  40 #ifdef HAVE_SYS_CDEFS_H
  41 #include <sys/cdefs.h>    // for __THROW
  42 #endif
  43 #include <gperftools/tcmalloc.h>
  44
  45 #ifndef __GLIBC__
  46 # error libc_override_glibc.h is for glibc distributions only.
  47 #endif
  48
  49 // In glibc, the memory-allocation methods are weak symbols, so we can
  50 // just override them with our own.  If we're using gcc, we can use
  51 // __attribute__((alias)) to do the overriding easily (exception:
  52 // Mach-O, which doesn't support aliases).  Otherwise we have to use a
  53 // function call.
  54 #if !defined(__GNUC__) || defined(__MACH__)
  55
  56 // This also defines ReplaceSystemAlloc().
  57 # include "libc_override_redefine.h"  // defines functions malloc()/etc
  58
  59 #else  // #if !defined(__GNUC__) || defined(__MACH__)
  60
  61 // If we get here, we're a gcc system, so do all the overriding we do
  62 // with gcc.  This does the overriding of all the 'normal' memory
  63 // allocation.  This also defines ReplaceSystemAlloc().
  64 # include "libc_override_gcc_and_weak.h"
  65
  66 // We also have to do some glibc-specific overriding.  Some library
  67 // routines on RedHat 9 allocate memory using malloc() and free it
  68 // using __libc_free() (or vice-versa).  Since we provide our own
  69 // implementations of malloc/free, we need to make sure that the
  70 // __libc_XXX variants (defined as part of glibc) also point to the
  71 // same implementations.  Since it only matters for redhat, we
  72 // do it inside the gcc #ifdef, since redhat uses gcc.
  73 // TODO(csilvers): only do this if we detect we're an old enough glibc?
  74
  75 #define ALIAS(tc_fn)   __attribute__ ((alias (#tc_fn)))
  76 extern "C" {
  77   void* __libc_malloc(size_t size)                ALIAS(tc_malloc);
  78   void __libc_free(void* ptr)                     ALIAS(tc_free);
  79   void* __libc_realloc(void* ptr, size_t size)    ALIAS(tc_realloc);
  80   void* __libc_calloc(size_t n, size_t size)      ALIAS(tc_calloc);
  81   void __libc_cfree(void* ptr)                    ALIAS(tc_cfree);
  82   void* __libc_memalign(size_t align, size_t s)   ALIAS(tc_memalign);
  83   void* __libc_valloc(size_t size)                ALIAS(tc_valloc);
  84   void* __libc_pvalloc(size_t size)               ALIAS(tc_pvalloc);
  85   int __posix_memalign(void** r, size_t a, size_t s)  ALIAS(tc_posix_memalign);
  86 }   // extern "C"
  87 #undef ALIAS
  88
  89 #endif  // #if defined(__GNUC__) && !defined(__MACH__)
  90
  91
  92 // We also have to hook libc malloc.  While our work with weak symbols
  93 // should make sure libc malloc is never called in most situations, it
  94 // can be worked around by shared libraries with the DEEPBIND
  95 // environment variable set.  The below hooks libc to call our malloc
  96 // routines even in that situation.  In other situations, this hook
  97 // should never be called.
  98 extern "C" {
  99 static void* glibc_override_malloc(size_t size, const void *caller) {
 100   return tc_malloc(size);
 101 }
 102 static void* glibc_override_realloc(void *ptr, size_t size,
 103                                     const void *caller) {
 104   return tc_realloc(ptr, size);
 105 }
 106 static void glibc_override_free(void *ptr, const void *caller) {
 107   tc_free(ptr);
 108 }
 109 static void* glibc_override_memalign(size_t align, size_t size,
 110                                      const void *caller) {
 111   return tc_memalign(align, size);
 112 }
 113
 114 // We should be using __malloc_initialize_hook here, like the #if 0
 115 // code below.  (See http://swoolley.org/man.cgi/3/malloc_hook.)
 116 // However, this causes weird linker errors with programs that link
 117 // with -static, so instead we just assign the vars directly at
 118 // static-constructor time.  That should serve the same effect of
 119 // making sure the hooks are set before the first malloc call the
 120 // program makes.
 121 #if 0
 122 #include <malloc.h>  // for __malloc_hook, etc.
 123 void glibc_override_malloc_init_hook(void) {
 124   __malloc_hook = glibc_override_malloc;
 125   __realloc_hook = glibc_override_realloc;
 126   __free_hook = glibc_override_free;
 127   __memalign_hook = glibc_override_memalign;
 128 }
 129
 130 void (* MALLOC_HOOK_MAYBE_VOLATILE __malloc_initialize_hook)(void)
 131     = &glibc_override_malloc_init_hook;
 132 #endif
 133
 134 void* (* MALLOC_HOOK_MAYBE_VOLATILE __malloc_hook)(size_t, const void*)
 135     = &glibc_override_malloc;
 136 void* (* MALLOC_HOOK_MAYBE_VOLATILE __realloc_hook)(void*, size_t, const void*)
 137     = &glibc_override_realloc;
 138 void (* MALLOC_HOOK_MAYBE_VOLATILE __free_hook)(void*, const void*)
 139     = &glibc_override_free;
 140 void* (* MALLOC_HOOK_MAYBE_VOLATILE __memalign_hook)(size_t,size_t, const void*)
 141     = &glibc_override_memalign;
 142
 143 }   // extern "C"
 144
 145 // No need to write ReplaceSystemAlloc(); one of the #includes above
 146 // did it for us.
 147
 148 #endif  // TCMALLOC_LIBC_OVERRIDE_GLIBC_INL_H_