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))) 87extern "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. 109extern "C" { 110static void* glibc_override_malloc(size_t size, const void *caller) { 111 return tc_malloc(size); 112} 113static void* glibc_override_realloc(void *ptr, size_t size, 114 const void *caller) { 115 return tc_realloc(ptr, size); 116} 117static void glibc_override_free(void *ptr, const void *caller) { 118 tc_free(ptr); 119} 120static 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. 134void 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 141void (* MALLOC_HOOK_MAYBE_VOLATILE __malloc_initialize_hook)(void) 142 = &glibc_override_malloc_init_hook; 143#endif 144 145void* (* MALLOC_HOOK_MAYBE_VOLATILE __malloc_hook)(size_t, const void*) 146 = &glibc_override_malloc; 147void* (* MALLOC_HOOK_MAYBE_VOLATILE __realloc_hook)(void*, size_t, const void*) 148 = &glibc_override_realloc; 149void (* MALLOC_HOOK_MAYBE_VOLATILE __free_hook)(void*, const void*) 150 = &glibc_override_free; 151void* (* 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_ 160