third_party/tcmalloc/chromium/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 // MALLOC_HOOK_MAYBE_VOLATILE is defined at config.h in the original gperftools.
  39 // Chromium does this check with the macro __MALLOC_HOOK_VOLATILE.
  40 // GLibc 2.14+ requires the hook functions be declared volatile, based on the
  41 // value of the define __MALLOC_HOOK_VOLATILE. For compatibility with
  42 // older/non-GLibc implementations, provide an empty definition.
  43 #if !defined(__MALLOC_HOOK_VOLATILE)
  44 #define MALLOC_HOOK_MAYBE_VOLATILE /**/
  45 #else
  46 #define MALLOC_HOOK_MAYBE_VOLATILE __MALLOC_HOOK_VOLATILE
  47 #endif
  48
  49 #include <config.h>
  50 #include <features.h>     // for __GLIBC__
  51 #ifdef HAVE_SYS_CDEFS_H
  52 #include <sys/cdefs.h>    // for __THROW
  53 #endif
  54 #include <gperftools/tcmalloc.h>
  55
  56 #ifndef __GLIBC__
  57 # error libc_override_glibc.h is for glibc distributions only.
  58 #endif
  59
  60 // In glibc, the memory-allocation methods are weak symbols, so we can
  61 // just override them with our own.  If we're using gcc, we can use
  62 // __attribute__((alias)) to do the overriding easily (exception:
  63 // Mach-O, which doesn't support aliases).  Otherwise we have to use a
  64 // function call.
  65 #if !defined(__GNUC__) || defined(__MACH__)
  66
  67 // This also defines ReplaceSystemAlloc().
  68 # include "libc_override_redefine.h"  // defines functions malloc()/etc
  69
  70 #else  // #if !defined(__GNUC__) || defined(__MACH__)
  71
  72 // If we get here, we're a gcc system, so do all the overriding we do
  73 // with gcc.  This does the overriding of all the 'normal' memory
  74 // allocation.  This also defines ReplaceSystemAlloc().
  75 # include "libc_override_gcc_and_weak.h"
  76
  77 // We also have to do some glibc-specific overriding.  Some library
  78 // routines on RedHat 9 allocate memory using malloc() and free it
  79 // using __libc_free() (or vice-versa).  Since we provide our own
  80 // implementations of malloc/free, we need to make sure that the
  81 // __libc_XXX variants (defined as part of glibc) also point to the
  82 // same implementations.  Since it only matters for redhat, we
  83 // do it inside the gcc #ifdef, since redhat uses gcc.
  84 // TODO(csilvers): only do this if we detect we're an old enough glibc?
  85
  86 #define ALIAS(tc_fn)   __attribute__ ((alias (#tc_fn)))
  87 extern "C" {
  88   void* __libc_malloc(size_t size)                ALIAS(tc_malloc);
  89   void __libc_free(void* ptr)                     ALIAS(tc_free);
  90   void* __libc_realloc(void* ptr, size_t size)    ALIAS(tc_realloc);
  91   void* __libc_calloc(size_t n, size_t size)      ALIAS(tc_calloc);
  92   void __libc_cfree(void* ptr)                    ALIAS(tc_cfree);
  93   void* __libc_memalign(size_t align, size_t s)   ALIAS(tc_memalign);
  94   void* __libc_valloc(size_t size)                ALIAS(tc_valloc);
  95   void* __libc_pvalloc(size_t size)               ALIAS(tc_pvalloc);
  96   int __posix_memalign(void** r, size_t a, size_t s)  ALIAS(tc_posix_memalign);
  97 }   // extern "C"
  98 #undef ALIAS
  99
 100 #endif  // #if defined(__GNUC__) && !defined(__MACH__)
 101
 102
 103 // We also have to hook libc malloc.  While our work with weak symbols
 104 // should make sure libc malloc is never called in most situations, it
 105 // can be worked around by shared libraries with the DEEPBIND
 106 // environment variable set.  The below hooks libc to call our malloc
 107 // routines even in that situation.  In other situations, this hook
 108 // should never be called.
 109 extern "C" {
 110 static void* glibc_override_malloc(size_t size, const void *caller) {
 111   return tc_malloc(size);
 112 }
 113 static void* glibc_override_realloc(void *ptr, size_t size,
 114                                     const void *caller) {
 115   return tc_realloc(ptr, size);
 116 }
 117 static void glibc_override_free(void *ptr, const void *caller) {
 118   tc_free(ptr);
 119 }
 120 static void* glibc_override_memalign(size_t align, size_t size,
 121                                      const void *caller) {
 122   return tc_memalign(align, size);
 123 }
 124
 125 // We should be using __malloc_initialize_hook here, like the #if 0
 126 // code below.  (See http://swoolley.org/man.cgi/3/malloc_hook.)
 127 // However, this causes weird linker errors with programs that link
 128 // with -static, so instead we just assign the vars directly at
 129 // static-constructor time.  That should serve the same effect of
 130 // making sure the hooks are set before the first malloc call the
 131 // program makes.
 132 #if 0
 133 #include <malloc.h>  // for __malloc_hook, etc.
 134 void glibc_override_malloc_init_hook(void) {
 135   __malloc_hook = glibc_override_malloc;
 136   __realloc_hook = glibc_override_realloc;
 137   __free_hook = glibc_override_free;
 138   __memalign_hook = glibc_override_memalign;
 139 }
 140
 141 void (* MALLOC_HOOK_MAYBE_VOLATILE __malloc_initialize_hook)(void)
 142     = &glibc_override_malloc_init_hook;
 143 #endif
 144
 145 void* (* MALLOC_HOOK_MAYBE_VOLATILE __malloc_hook)(size_t, const void*)
 146     = &glibc_override_malloc;
 147 void* (* MALLOC_HOOK_MAYBE_VOLATILE __realloc_hook)(void*, size_t, const void*)
 148     = &glibc_override_realloc;
 149 void (* MALLOC_HOOK_MAYBE_VOLATILE __free_hook)(void*, const void*)
 150     = &glibc_override_free;
 151 void* (* MALLOC_HOOK_MAYBE_VOLATILE __memalign_hook)(size_t,size_t, const void*)
 152     = &glibc_override_memalign;
 153
 154 }   // extern "C"
 155
 156 // No need to write ReplaceSystemAlloc(); one of the #includes above
 157 // did it for us.
 158
 159 #endif  // TCMALLOC_LIBC_OVERRIDE_GLIBC_INL_H_